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Guidelines for building bamboo-reinforced masonry in earthquake-prone areas in India

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Guidelines for building bamboo-reinforced masonry in earthquake-prone areas in India

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Content INFORMATION TO USERS This manuscript has been reproduced from the microfilm master UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. ProQuest Information and Learning 300 North Zeeb Road. Ann Arbor, Ml 48106-1346 USA 800-521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. GUIDELINES FOR BUILDING BAMBOO-REINFORCED MASONRY IN EARTHQUAKE-PRONE AREAS IN INDIA by Sreemathi Iyer A Thesis Presented to the FACULTY OF THE SCHOOL OF ARCHITECTURE UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements of the Degree MASTERS OF BUILDING SCIENCE M ay 2002 Copyright 2002 Sreemathi Iyer Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 1411790 _ _ ® UMI UMI Microform 1411790 Copyright 2003 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UNIVERSITY OF SOUTHERN CALIFORNIA The Graduate School University Park LOS ANGELES, CALIFORNIA 90089-1695 Thi s thesi s, w ritten by Under the direction o f h .t.t.. Thesi s Commi ttee, and approved by a ll its members, has been presented to and accepted by The Graduate School , in p a rtia l fu lfillm en t o f requirements fo r the degree o f J M A S 1 E & , s a m L J E - Dean o f G raduate Studies Date I, Loo ^ • SI S C O M M ITTEE k 4 d d L — yChairperson Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Dedication This thesis is dedicated to my family in India who m ade my dream a reality. Sreemathi Iyer Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Acknowledgements This thesis owes its successful completion to the contribution of numerous individuals and groups. Firstly the members of my thesis committee for their undaunted support and encouragement. Prof. Goetz Schierle for spending all the hours helping me to solve all my problems. Prof. Marc Schiler for all the timely advice, feedback, and of course tools. Prof. Yan Xiao guiding me and allowing me to use the Civil Engineering lab facilities. Special thanks to Lance Hill, the Civil Engineering Lab manager, without whom my tests would not have been possible. Sumit Mohanty, my best friend, for boosting my morale and turning up when needed. My MBS classmates, especially Kang Kyu Choi and Suganya Thiagarajan, for all the timely help. Ralph Evans (Botanical Partners Ltd.) and Mark (Frank Cane & Rush supply) for their insights into bamboo. Rajib Shaw (EDM) for giving me access to all the background information I needed to get going in the right direction. CUREe, for giving me the opportunity to participate in seismic research, thereby consolidating my foundation in seismic design. Sreemathi Iyer h i Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table of Contents Dedication................................................................................... ii Acknowledgements............................................................................................................. iii List of tables........................................................................................................................... v List of figures.......................................................................................................................... vi List of graphs......................................................................................................................... ix Abstract................................................................................................................................. x -Key words Hypothesis.............................................................................................................................. xi I. Background 1. Seismic 1 Introduction..................................................................................................... 1 2 Seismicity in India .............................. 2 3 Bhuj Earthquake: January 26, 2001 disaster statistics................................. 7 4 General Construction Practices in Bhuj....................................................... 10 5 Proposed rehabilitation technique for RC structures................................. 18 6 Good Performances in the Bhuj Earthquake.............................................. 19 7 Uniform Building Code (UBC) equivalent static force method of seismic design................................................................................................................ 20 8 Conclusions & further research..................................................................... 24 2. Bamboo 9 Introduction to bam boo................................................................................ 26 10 Bamboo properties....................................................................................... 28 1 1 Bamboo use in construction......................................................................... 32 II. Reasearch 3. Introduction 12 Initial assumptions & calculations................................................................. 38 13 Testing needs............................................................... 39 14 Test protocol.................................................................................................... 40 15 Test apparatus................................................................................................. 46 16 Test results........................................................................................................ 51 4. Seismic design guidelines 17 Computations.................................................................................................. 59 18 Guidelines for building bamboo-reinforced masonry homes................... 66 19 Cost comparison............................................................................................ 77 in Conclusions and recommendations........................................................................... 78 IV Bibliography.................................................................................................................... 79 iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. List of Tables Table 2.1 History of earthquakes in India......................................................... 2 Table 7.1 Z-factors according to seismic zones in the United States............ 20 Table 10.1 Strength of bamboo acc. to "Kerala State Bamboo Corpn. Ltd." Tests. 28 Table 10.2 Strength of bamboo according to Francis E. Brink & Paul J. Rush......... 29 Table 10.3 Species of bamboo commonly available in India....................................29-30 v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. List of Figures Fig 2.1 Seismicity map of South-east Asia..................................................................... 3 Fig 2.2 Tectonic Map of India........................................................................................ 4 Fig 2.3 M ap of seismological observatories in India by IMD...................................... 5 Fig 2.4 Seismic Zoning Map of India............................................................................. 6 Fig 3.1 Map showing the Bhuj Earthquake.................................................................. 7 Fig 3.2 Map of showing affected areas around Bhuj................................................. 8 Rg 4.1 View of Bhonga - exterior &interior................................................................ 1 1 Fig 4.2 Bhongas that survived the earthquake.......................................................... 1 1 Fig 4.3 Bhongas that collapsed in the calam ity......................................................... 12 Fig 4.4 Typical masonry house plan............................................................................. 12 Fig 4.5 Typical brick masonry house............................................................................ 12 Fig 4.6 Typical cement block masonry house............................................................ 12 Fig 4.7 Collapsed unreinforced brick house............................................................... 13 Fig 4.8 Collapsed Cement block masonry structure ..................................... 13 Fig 4.9 Plan of typical RC apartment complex.......................................................... 14 Rg 4.10 View of a typical RC complex......................................................................... 15 Rg 4.11 Typical structural systems used in initial construction.................................... 15 Rg 4.12 Typical methods used in retrofit construction................................................ 16 Rg 4.13 Absence of plinth beams................................................................................. 17 Fig 4.14 Discontinuous members................................................................................... 17 Fig 4.15 Inadequate load transfer mechanism........................................................... 17 Rg 4.16 No support for rooftop w ater tanks................................................................ 17 vi Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Rg 4.17 Collapsed soft stories....................................................................................... 17 Fig 5.1 Typical failures in RC structures...................................................................... 18 Fig 5.2 Glass fiber roll, precured GFRP plate and rebar......................................... 18 Rg 6.1 Examples of good performances during the Bhuj Earthquake................. 19 Rg 7.1 Lateral forces increase with height due to increasing acceleration 22 Fig 8.1 Comparison of popular building techniques in Gujarat and Bhuj' 24 Fig 9.1 Various types of Bamboo............................................................................... 26 Fig 9.2 Bamboo clumps.............................................................................................. 27 Fig 9.3 Bamboo building by J, Moran, Guayaquil, Ecuador.................................. 27 FiglO.l Full culms and splints........................................................................................ 28 Fig 11.1 Example of Bamboo house........................................................................... 32 Fig 11.2 Bamboo scaffolding....................... 33 Fig 11.3 Bamboo board................................................................................................ 34 Fig 11.4 Bamboo m at wall............................................................................................ 35 Fig 11.5 Bamboo tile roofing......................................................................................... 35 Fig 11.6 Bamboo shingles.............................................................................................. 36 Fig 11.7 Bamboo truss.................................................................................................... 36 Rg 11.8 Simon Velez pavilion of bam boo................................................................. 37 Rg 11.9 Bamboo-reinforced concrete silo................................................................. 37 Rg 11.10 Bamboo reinforcement.................................................................................. 39 Rg 14.1 Wooden support for specimen...................................................................... 40 Rg 14.2 Specimen loaded in tester.............................................................................. 40 Rg 14.3 Glued specimen loaded for testing.............................................................. 41 Rg 14.4 Glued support end.......................................................................................... 41 vii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Fig 14.5 Doweled support............................................................................................. 41 Rg 14.6 Specimen with no supports loaded in tester............................................... 42 Fig 14.7 Single node test specimen............................................................................ 42 Rg 14.8 Mortar sample loaded in tester..................................................................... 43 Fig 14.9 Mortar sample................................................. 43 Fig 14.10 Brick sample loaded in tester........................................................................ 44 Rg 14.11 Brick with em bedded splint........................................................................... 44 Rg 14.12 Mortar Block for Comparative test............................................................... 45 Fig 15.1 5590 HVL series Universal tester and com puter for operation.................. 46 Fig 15.2 Parts of Universal tester 559o HVL series...................................................... 47 Fig 15.3 Dual test space in Universal tester............................................................... 47 Fig 15.4 Crosshead styles............................................................................................ 48 Fig 15.5 In-head grip options...................................................................................... 48 Rg 15.6 User control panel.......................................................................................... 49 Fig 15.7 Bamboo splitting m ethod............................................................................. 50 Fig 15.8 Splitter............................................................................................................... 50 Fig 15.9 Rubber Mallet................................................................................................. 50 Fig 16.1 Failed support ................................................... 52 Rg 16.2 Failed bam boo splint - single and double node........................................ 54 Fig 17.1 Assumed one-story residence....................................................................... 60 Rg 17.2 Plan of brick wall............................................................................................. 61 Fig 17.3 Full culm ............................................................................................................ 62 Rg 17.4 1/10th splint........................................................................................................ 62 Rg 17.5 Shear wall cover............................................................................................. 62 viii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Rg 17.6 Shear wall cover............................................................................................ 64 Fig 18.1 Shear wall placem ent.................................................................................... 67 Fig 18.?. Shear wall in elevation.................................................................... 67 Rg 18.3 Foundation rebars........................................................................................... 68 Fig 18.4 Full culm and splint......................................................................................... 69 Fig 18.5 Crossbar splitter.............................................................................................. 71 Fig 18.6 Other tools for splitting................................................................................... 71 Fig 18.7 Mechanical splitter......................................................................................... 71 Fig 18.8 Section thru’ foundation............................................................................... 73 Fig 18.9 Stretcher bond................................................................................................ 75 Fig 18.10 Plan of cavity wall.......................................................................................... 75 Fig 18.11 Isometric view of cavity wall......................................................................... 75 Fig 18.12 Section thru’ wall............................................................................................ 75 Rg 18.13 Reinforcing around window.......................................................................... 76 Fig 18.14 Reinforcing around door............................................................................... 76 Fig 18.15 Collar beam above wall................................................................................ 77 Fig 18.16 Collar beam in cavity..................................................................................... 77 ix Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. List of Graphs Graph 3.1 Comparison of different types of property damages......................... 9 Graph 16.1 Failure due to support slippage............................................................. 51 Graph 16.2 Failure due to cracking of glued supports............................................ 52 Graph 16.3 Tensile test with doweled supports........................................................ 53 Graph 16.4 Successful tensile test with double node specimen ........... 54 Graph 16.5 Tensile test with single node specimen.................................................. 54 Graph 16.6 Bond test with specimen em bedded in mortar block......................... 55 Graph 16.7 Bond test with specimen em bedded in brick pier............................... 56 Graph 16.8 Bond test with specimen em bedded in equivalent area mortar block 57 Graph 16.9 Comparison of Bond Strength between presence & absence of node in mortar block................................................................................ 57 Graph 16.10 Comparison of Bond Strength between varying size of bam boo splints 58 x Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Hypothesis In response to the devastating Earthquake of January 26, 2001 in Bhuj, India, it is assumed a low-cost alternative with better seismic performance can be developed and tested, using bamboo-reinforced masonry, similar to the traditional technology prevalent in the region. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 1. Introduction The recent earthquake in India, that literally shook peoples lives on January 26, 2001, was an event of catastrophic proportions. It caused widespread dam age to life and property, both of which if not avoided could have been minimized. The count of human life losses rose above 25,000. Over 370,000 houses were com pletely destroyed and over 922,000 partially destroyed, total damages exceeding 5 billion U S Dollars. Around 50% of this dam age, upto 2.5 billion U S Dollars, were incurred due to household property damage. It is obvious that a lot of these losses could have been minimized if the houses were better engineered. However, an expectation of this sort is quite difficult to fulfill. In a developing country like India, a person from the lower economic strata is incapable of building engineered houses. Most "lower-income" group houses are built by just hiring a mason or a contractor, neither qualified to engineer the building. Also the chief building system preferred by these people is bearing masonry using brick, clay block or cement block. These systems, if not reinforced, are most susceptible to com plete collapse during seismic activity. The objective of this thesis is to provide a comprehensive set of guidelines for the benefit of the average house-builder to construct seismically safe, reinforced bearing masonry using bam boo as alternative reinforcing material. Researches in the past have proved bamboo to be the fastest renewable natural building material and a worthy alternative to steel. However, the merits of bam boo have been continuously overlooked with the advent of "modernity" in building construction. 1 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 2. Seismicity in India Seismicity of a place can be defined as the distribution of earthquakes in space, time and magnitude in that area. India, being a large landmass, experiencing the constant "continental drift” northward, has definitely had a large number of earthquakes. A list of significant ones in the last 180 years is as below (Earthquakes of magnitude 8 or greater have been highlighted): DATE EPICENTRE LOCATION MAGNITUDE Lat( Deq N ) Lonqf D eq E ) 1819 JUN 16 23.6 68.6 KUTCH.GUJARAT 8.0 1869 JAN 10 25 93 NEAR CACHAR. ASSAM 7.5 1885 MAY 30 34.1 74.6 SOPOR. J&K 7.0 1897JUN 12 26 91 SHILLONGPLATEAU 8.7 1905 APR 04 32.3 76.3 KANGRA. H.P 8.0 1918JUL08 24.5 91.0 SRIMANGAL. ASSAM 7.6 1930 JUL02 25.8 90.2 DHUBRI. ASSAM 7.1 1934JAN 15 26.6 86.8 BIHAR-NEPALBORDER 8.3 1941 JUN 26 12.4 92.5 ANDAMAN ISLANDS 8.1 1943 OCT 23 26.8 94.0 ASSAM 7.2 1950 AUG 15 28.5 96.7 ARUNACHAL PRADESH -CHINA BORDER 8.5 1956 JUL2I 23.3 70.0 ANJAR. GUJARAT 7.0 1967 DEC 10 17.37 73.75 KOYNA, MAHARASHTRA 6.5 1975 JAN 19 32.38 78.49 KINNAUR. HP 6.2 1988 AUG 06 25.13 95.15 MANIPUR-MYANMAR BORDER 6.6 1988 AUG 21 26.72 86.63 BIHAR-NEPAL BORDER 6.4 1991 OCT 20 30.75 78.86 UTTARKASHI, UP HILLS 6.6 1993 SEP 30 18.07 76.62 LATUR-OSMANABAD, MAHARASHTRA 6.3 1997 MAY 22 23.08 80.06 JABALPUR.MP 6.0 1999 MAR 29 30.41 79.42 CHAMOLI DIST, UP 6.8 2001 JAN 26 23.6 69.8 BHUJ. GUJARAT 7.6 Table 2.1: History of Earthquakes In India (IMD website, 2002) Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The following map will help to get a better understanding of the seismicity of South- East Asia. The concentration of earthquake occurrences almost along the border of India can be explained by continental drift of the Indian Peninsula northward into Asia (earlier Eurasia). Seismidty of Southern Asia (above magnitude 3.0 Ms) % I n n n m c . i i KEY- / t o ' I! / / 00 » t o o * O O “ I • • — • • “ ■ Fig 2.1: Seismicity Map of South-East Asia (B ritish Geological Survey. 2001) 3 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The seismicity in the country can be better understood by tectonic plate map of India, which is as below: i ? 100’ 104* n — r Pdshowar T IB E T A N ~ ^ PLATEAU Delhi,?' S* s' * & t i s s t e v 5 » » / ' K V . - ' ; V V , 0 ' ^ Bomba OfliPHlCf I M DI Afi OCEAN 9 6 * ICO* 104 Fig 2.2: Tectonic Map of India (National Geophysical Research Institute - India. 2001) The tectonic plate studies and seismological studies are being advanced by setting up multiple observatories and using advanced instruments. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. JODHPUR EDABAD SURAT RAUHKE JABALPUR HYDERABAD BANGALORE Fig 2.4: Seismic Zoning Map of India The Seismic Zoning Map shown above divides the sub-continent into zones based on the intensity of earthquakes in the area. Zone I has the lowest and Zone V has the highest magnitude or probability of earthquakes. 6 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 3. Bhuj Earthquake: January 26,2001 disaster In the early hours of the Republic day of India, January 26 2001, people of India experienced violent tremors. The day the Constitution of Independent India had been written, 54 years ago, the residents of Bhuj and the neighboring areas experienced a powerful earthquake, with a magnitude of 6.9 on Richter scale. iwm.mtpaottndla.eom \ THE SEVERE EARTHQUAKE THAT HIT INDIAN SUBCONTINENT ON t)AMMU ft KASHMm / JAN 26TH 2001 .S rin.fl.r (M agnitude- 6.9 on Richter Scale) N n y HIMACHAL ____ \ PRAOESH CHINA s . \ (Tibet) n o n ** jafdtgarh UTTARANCHAL \ ARUNACHAL PRAOESH HARYANA OELHI . UTTAR \ \ PRAOESH^ - *" RAJASTHAN Jaipur z DADAR HAVEU KARNATAKA Blangalorc* LAKSMAOWEEP * • i SIKKIM Gangtok tjnagar \ • Lucknow I \ # Kanpur Patna IlHAR •^ s p u f .NAGALAND Mlogg ^ MEGHaC aYA? . MANIPUR # B h o p a l j ) '* MADHYA PRAOESH JHARKHIfijO B E N G A ^ j 0 V A M!Z0RAM ;ur»* J * lnd0,r CHHATTISGARH Calju|}ft) \ \-> J ^iigpur • \ I a H a ra s h tra / * oRresA j BANGLADESH v / BhuoaneaAwar / (Bombay) / , y Puna / • !s ' t Hydatabad VMakhapatnam ^ ANDHRA f Z P an a j^r" PRADESH,. / YANAM /B A Y O F B E N G A L GOA-W / (Pondicherry) / B h u j-B p ic a n tra a f tfca la rtk a w b a (Madraif ^ PONDICHERRY Coimbatore!^ (Puduchcbery) -onaTcharry) \ #TAMILNAOtlKARAlKAL KERALA X ( 5 ondicherry) ^ Madurai) Thiru 0 O \ ° Port Blair Q ANDAMAN & NICOBAR ISLANDS 8 Copyright (C) Compare Infobasa Pvt. L td 2000*2001 Fig 3.1: Map showing the Bhuj Earthquake (www.mapsoflndia.com) Bhuj' was earlier believed to be the epicenter as is noted in the map above. The epicenter of the earthquake was, however, 13 kilometers North-West of a town called Bhachau (Kutch, Gujarat). The quake was felt all over India and even in parts of Bangladesh, Nepal, and Pakistan. 7 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PAKISTAN RANN OF KACHCHH , Khavda S A B tl M O U A K * 4 * P i £ f i 9 « 3 N S » H im iV W Lo d ran i' / N wl00Kot..hwitahJduli PH » l'P u f — aPyi'QC OPaXandhro I ; ' v " " * ’ t i!a ro $ ir& 1 I3S ^ ffitiy a * a n y a fl2 ^ — t e i _ T 1 1 C*M ota-no-m adh Ratadiya '"^ Q R a v a b a r ° \ l ^ >3S4fv« * . ^ ^ R a m v a d i N efia Khan VsTdasar * Adeaar* o Bhojardo Bhimaaar Cnobari ffra la s a v a QNiruna OQhimoar Taper RaiHI 1 1 A & todai udramata O ~ *” B h m p h M u w — > > Chiral 0 Samakhiya#l' *' Q f • kh *p" ° ^ s^ B '-"Kaehel. R a fn a / O vizan U K^thara Kotdl j SuntharP A q ° Godhaiaa \ Koday A y i j W ^ % « V s . , ? T Mo napar M apnttjaSeala JAMNAOAR Copyriflh1(c)CQmpare Inlobase Pvt.Ltd.2000-2001 Fig 3.2: Map ot showing affected areas around Bhuj (www.mapsoffndla.com) This map takes a closer look at Bhuj and the neighbors marking out areas on the basis of the amount of dam age due to Bhuj. A general overview of the dam age provides the following numbers (Survey, 2001): 1.59 m of 3.78m population affected • Villages dam aged • Deaths • Injured Critically Inj'ured • Livestock (cattle) loss - 7,900 - 20,000 - 166.000 - 20,700 - 20,700 8 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Comparison of property damages during the Bhuj Earthquake Commercial Industrial Infrastructure Q - Public Utilities Household 0 500 1000 1500 2000 2500 3000 Household Public Utilities Infrastructure Industrial Commercial Series I 2500 125____________225 1000___________ 625 _ Loss value in US Dollars (100.000 $) Graph 3.1: Comparison of different types of property damages Studies estimate the total monetary loss to be close to 5 billion U S Dollars. The graph above compares the losses to different types of establishments in U S Dollars highlighting the extensive dam age to households, which has far exceeded that of any other kind of establishment. The losses to life and residential property alike have been phenomenal. This brings forth a need to study them in greater detail and provide adequate retrofit and mitigation methods for this section of construction. This shall be the focus of the chapters hereafter. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. a. Traditional Kutchchi houses fBhonaa) This traditional type of housing is typically circular in plan with a conical roof. The inner diameter varies between 3 to 6 meters. A bhonga typically has walls of sun- dried mud (adobe) blocks and a bamboo-framed roof covered with thatch. In some cases, use of lintel bands at the top of the walls and bam boo framing in the walls is possible. I Fig 4.1: View of a Bhonga -exterior & interior Seismic Performance Some examples of this ancient building tradition have performed surprisingly well in the Bhuj earthquake. An analysis of the structures shows the following strengths and weaknesses. Strengths • Circular shape, hence excellent resistance to lateral forces • Thick adobe walls - high in-plane stiffness . Light-weight roofing with ductile materials Ffg b h o n g a s that survived the earthquake • Use of lintel bands and collar bands in some cases as reinforcing members II Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Weaknesses • Poor quality of materials used for construction • Use of one single post to support the roof at the center Fig 4.3: Bhongas that collapsed in the calamity b. Unreinforced Burnt Brick Masonry & Cement Block Masonry These structures are typically single-storied brick masonry structures, have an exterior wall thickness of 300 - 350 mm (11.8" - 13.7") and interior walls are about 230 mm (9"). In case of cem ent block masonry structures the wall thickness is uniform 200 mm (7.8") for exterior » n IS n- Room 1 E.7 n W 1 02 8 .Q a W2 Fig 4.4: Typical masomy house plan and interior walls. Both types have roofs consisting of bam boo/ wood purlins covered with clay tiles. In some cases, a concrete slab of about 100 mm (4") thickness may also be used. Fig 4.5: Typical brick masomy house Fig 4.6: Typical cement block masonry house 12 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Seismic Performance Though these are relatively stronger when compared with the bhongas, but they have their own problems in case of seismic activity. Their seismic strengths and weaknesses are as below: Strengths • Use of lintel bands and collar bands in some cases as reinforcing members Weaknesses • Improper connections • Openings very close to corners • Inadequate shear resistance near openings • Damage to light-weight roofs • Asymmetrical plan 13 F ig 4.7: Collapsed Unreinforced brick house Fig 4.8: Collapsed Cement Block masonry structure Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. c . Reinforced Concrete Reinforced Concrete structures are normally multi-storied structures. The structural system consists of moment-resisting frames resting on shallow isolated footings. The structures have infill wall panels of brick, cut-stone or cement block. Fig 4.9: Plan of a typical RC apartment complex Initially RC structures built for office or commercial purposes and residential dwellings were more of the single-family independent house type. However, shortage of land and high land values necessitated the building of multi-storied residential complexes. RC is a better solution with respect to seismic activity and is a labor- intensive type of construction, advantageous for India with a large labor force. 14 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The seismic strengths of RC structures are: • RC moment-resisting frame with brick infill most effective in areas prone to seismic activity. • Rectangular plans, symmetric framing system without horizontal or vertical discontinuities quite effective. • Symmetrical lift cores act like shear walls. Fig 4.10: View of a typical R C complex • Closely-place stirrups with ends bent add to the ductility factor. In order to understand the seismic weakness of RC construction, it is necessary to look into the typical structural systems used in RC construction for initial construction and retrofitting structures. m i m i m i m i m i n n V S / S / S A B l l " Fig 4.11: Typical Structural systems used in initial construction S (si) Type (i) - Framed structure with soft story. Type (ii) - Framed structure with upper floors cantilevered beyond the soft story. Type (iii) - Framed structures with a concrete shear core. 15 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Seismic Weaknesses • Configuration problem - building wings must be separated by seismic joints • Inadequate soil tests for foundation design • No plinth beams for reducing slenderness of ground floor columns • Discontinuous horizontal and vertical members • Inadequate transfer mechanism of lateral loads from other areas to lift cores • Inadequate support to water tanks on roof • Inadequately strengthened soft stories for parking • Poor quality of concrete Fig 4.15: Inadequate transfer mechanism Fig 4.13: Absence of plinth beams Fig 4.14: No Support for rooftop water tanks Fig 4.14: Discontinuous members Fig 4.17: Collapsed soft stories 17 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 6. Good Performances in the Bhuj Earthquake Though there was widespread dam age that seemed to be the most common feature of the landscape after the seismic disaster, there were examples of structures that surprisingly held their own. Some of these were located quite close to the epicenter. These structures were analyzed to learn the reasons for the good performance. They are as below: • These structures were mostly industrial facilities. • This could mean that they were built to higher standards of construction and better quality materials. • Often times the construction companies that are commissioned to build industrial facilities in India are international - like American or German companies. This highlights the possibility of greater quality control. J h n fe flK S Ss_- ■ - R M s d L .. • R u i a i w ^ * .... 311522 (2 Fig 4.1: Examples of Good Performances during the Bhuj Earthquake 19 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 7. Uniform Building Code (UBC) Equivalent Static Force Method of Seismic Design Seismic base shear is based on Newton's law: f = m a (Force = Mass x Acceleration) The UBC Static Method defines base shear using the following acceleration: Base Shear, V = Dead Load x Seismic Acceleration ZIC Base Shear, V = W--------- Rw Where, W= Building dead load (DL) + 25% live load (LL) of warehouses only Z = Seismic Zone factor I = Seismic Importance factor C= Ground Motion Amplification Coefficient Rw= Lateral-force-resisting system Coefficient (min 4 to a max 12) ■ Seismic Zone Factor (Z1: The seismic zone factor, 1, corresponds to the expected peak ground acceleration as defined by the Seismic Zone map for the United States (UBC Figure 16-2). Z-factors are defined as: Zones: ZoneO Zone 1 Zone2A Zone 2B Zone 3 Zone 4 Z-factors 0 0.075 0.15 0.2 0.3 0.4 Table 7.1: Z-factors according to seismic zones in the United States 20 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ■ Seismic Importance Factor (I): The seismic importance factor. I = 1.25, for essential or hazardous facilities (hospitals, police and fire stations) and I = 1 for all other occupancies. Increasing the importance factor can be looked at increasing the seismic forces expected to act on the structure. ■ Ground Motion Amplification Coefficient (C): The ground motion amplification coefficient, C, is a coefficient that accounts for the effect of periodic modes of vibration, damping, and soil quality on a building’s response to typical seismic ground motion. C= 1.25 S / T 2/3 Where, S = Site Coefficient Si= 1.0 rock-like and stiff dense soil < 200' deep Sj = 1.2. medium-dense or stiff soil > 200' deep S 3 = 1.5 (default), soft to medium stiff soil > 20’ deep S < = 2.0, soft clay > 40’ deep T = Period of Vibration of the structure T = Ct h »/« Ct = 0.035 for steel moment frames Ct = 0.03 for concrete moment frames and eccentrically braced frames Ct = 0.02 for all other structures h = height of the structure above the ground 21 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ■ Lateral- Force-resistina system Coefficient (Rw) The lateral-force-resisting system coefficient Rw, relates the building's structural system (specifically, the part of the structural system that resists horizontal forces) to its performance under seismic loads. In particular, the structure's ability to absorb energy (ductility) is rewarded in assigning values to Rw. These values range from 12 for steel or concrete "special moment-resisting frames" down to 4 for various bearing wall systems including concrete and heavy timber braced frames resisting both gravity and lateral loads. The structure is assumed to behave like a vertical cantilever rigidly attached to the ground. Hence lateral forces at higher stories will be greater. Fig 7.1: Lateral forces increase witti height due to increasing acceleration (Schierte. 1994) Lateral forces per level are computed as: F * = (V - Ft) W xhx / Xwihi Where F x = Lateral force at each story W= total dead weight of story h = height of story above ground n = number of stories F » = whip force on top of the building in addition to F n F » is computed as: F » = 0.07TV <= 0.25 V for T > 0.7 seconds Y 22 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Shear distribution: Shear increases from top to bottom since each floor resists its own force plus all forces above. Overturning moment distribution: The overturn moment at each level is the sum of all forces above that level multiplied by their respective lever-arm to the level considered. 23 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Further Research It has been proved [n previous researches that the best way to seismically strengthen masonry structures is to reinforce them. Steel rebars are commonly used for this purpose. However, steel is an expensive material for a third world country like India and most people living in unreinforced masonry structures do so because of insufficient money for better houses. Steel is practically unaffordable to this kind of people. It is therefore necessary to propose an alternative material to be used as rebars. In my further research, I propose to study the use of bam boo as a rebar for masonry construction. Why Bamboo? • It is the fastest-growing renewable natural building material. • It is much less expensive than steel. • The material is very familiar to the people of Bhuj. • Tests have proven that bamboo is a viable (if not better!) alternative for steel, concrete and masonry as an independent building material. 25 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 9. Introduction to Bamboo Bamboo is primarily a type of giant grass with woody stems. The stems are called “shoots" when the plant is young and "culms" when the plant is mature. Fig 9.1: Various types of Bamboo Each bam boo plant consists of two parts - the "culm’Vstem that grows above the ground and the underground "rhizome" that bears the roots of the plant. Bamboo grows in either clumps or like runners. Bamboo growing in a clump adds a new shoot around one central culm thereby increasing the clump size radially. As for runners, they just literally "run" around, growing in a haphazard manner. "A single bam boo clump can produce up to 15 kilometers of usable pole (up to 30 cm in diameter) in its lifetime." 26 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 10. Bamboo Properties The primary focus of this study is the use of bamboo in the field of construction. Hence this chapter shall concentrate on the properties of bam boo that are useful for building. Researches in the past have yielded knowledge of over 27 species of timber bamboo, having varying resistance to cold, sunlight, diameter, height. Bamboo used in construction maybe used as a full culm or splits (3/8" - 1 /2" w ide). Fig 10.1: Full culms & splints Studies carried out to test the structural properties of bamboo by the "Kerala State Bamboo Corporation Ltd." show the following results (converted to psi): Tensile strength test a) Tensile strength parallel to the grain direction of cross band 6450 b) Tensile strength perpendicular to the grain direction of cross band 1590 Flexural strength test a) Flexural strength parallel to the grain direction of cross band 12,200 b) Flexural strength perpendicular to the grain direction of cross band 6060 Compressive strength test a) Compressive strength parallel to the grain direction of cross band 5435 b) Flexural strength perpendicular to the grain direction of cross band 3265 Table 10.1: Strength of bamboo acc. to “Kerala State Bamboo Corpn. ltd." tests 28 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Francis E. Brink and Paul J. Rush did a study and calculations way back in February 1966 incorporating bamboo as rebar in RC beams and columns. This project was carried out at the U.S. Naval Civil Engineering Laboratory, Port Hueneme, California. This study assumes the following values for the mechanical properties of the material: Mechanical Property Symbol Value (psi) Ultimate compressive strength 8,000 Allowable compressive stress a 4,000 Ultimate tensile strength 18,000 Allowable tensile stress a 4,000 Allowable bond stress u 50 Modulus of elasticity E 2.5x106 Table 10.2: Strength of bamboo according to Francis E . Brink ft Paul J. R u s h Since bamboo is a natural material, different species perform differently for the same set of tests. The above-mentioned values are only ballpark figures to use in calculations. To be more accurate, the right kind of bamboo to be used for construction might have to be subjected to the standard tests to be able to determine a value for calculation purposes. The following species of bam boo are commonly found in India (listed alphabetically by botanical names): 1. B am b u sa lo n g is p fc u la ta C om m o n N am e: "M itenga" Bengal) &'Thaikwa"( Burma), Origin: Bangladesh/India., Specification: 1 Bm x 10cm to +5 d e g C., Forms beautiful o pen clumps with w ell-spaced straight ivory-striped greyish-green culms. Large d eco rative leaves a n d structurally g o o d . S p e c ta c u la r light b lu e /g re e n edible shoots a re striped c re a m , h a v e a scattering o f strong, dark contrasting hairs on th e culm le a f a n d a wrinkled, hairless fairly flat b ro ad b la d e ._________ Table 10.3: Species of bamboo commonly available in India 29 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 2. B a m b u sa o iiv e ria n a C om m o n N am e: "W apgusan". Origin: Burma and India., Specification: 10m x 5cm to 0 d e g C . A very pretty m o d e ra te sized dense clum ping b a m b o o with thick-w alled strong, straight, glossy, g reen culms. Smallish, very p o in te d d e lic a te leaves. Edible shoots are purple tinged green sporting b lack hairy stripes on the blades. Very q o o d for fishinq poles. 3. B a m b u sa tu ld a C om m o n N a m e : Bengal B am boo. Origin: India, w h ere it is a m ajor source o f p a p e r pulp.. Specification: 25m x 8 cm to -2 d e g C . A fast grow ing often deciduous superior structural b a m b o o (tensile strength tested a t 52,000 psi). It has large leaves on u p p e r branches a n d fe w e r smaller leaves low er dow n. Fairly straight very smooth d ark green culms. Edible slightly bitter shoots (often pickled) h a v e sp ectacu lar bulging p a le blue p o w d e r co vered sheaths with w id e green blades that flair out alm ost horizontal to th e shoots' surface. Used extensively for furniture, basket m aking a n d a w id e ran g e of household utensils a n d as co ncrete reinforcing. The sacred flute called "Eloo" used by th e priests of A runachal Pradesh is m a d e from B tulda. 4. D e n d ro c a la m u s b ra n d ls ii C om m o n N am e: Sweet D ragon, Origin: India., S pecification: 36m x 20cm to -4 d e g C. The tallest b a m b o o in the world, this vigorous giant produces thick-walled strong green culms co vered with a velvet bloom o f p a le hairs im parting a slightly milky a p p e a ra n c e . Strong aerial root grow th on the low er nodes. Lower culms branchless for m any m eters then masses o f very large light g reen rough textured leaves. Huge delicious ed ib le shoots a re dark bronze a n d hair c o v e re d with purple blades. Extensively used for house construction, furniture m aking an d p a p e r production b ut b ecom in g hard to find in Asia. 5. D e n d ro c a la m u s strlctus C om m on N am e: "M ale B am boo”. Syn Bambusa stricta., Ongin: India., Specification: 18m x 8cm to -7 d e g C . A drought-resistant b a m b o o with small light g reen furry leaves. Its strong low er e re c t grey-green slightly rough culms a re often w ithout hole for a b o u t half their length a n d a re w ithout low er branches or leaves displaying the extrem ely tightly clu m p ed culms. The pendulous u p p e r culms a n d their fine le a fe d display are very g raceful. An a d d e d feature is th e visible retained paper-like low er culm leaves. The shoots light g reen a n d lightly p o w d e re d a re e d ib le . A m a jo r p a p e r pulp a n d structural b a m b o o o f India. Table 10.3: Species of bamboo commonly available In India (contd.) 30 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Of the species mentioned in Table 10.3, all except the Bambusa oliveriana could be used for construction purposes. Apart from these species, the Bambusa tuldoides, originating in China also has a very high tensile strength and is recommended for use in construction. 31 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 11. Bamboo in Construction Bamboo is the fastest growing, renewable natural resource known to us. It is a small wonder, therefore, that this material was used for building extensively by our ancestors. Bamboo being a natural material has its disadvantages like infection by insects and fungi, poor fire-resistance. Bamboo used in the construction industry can be either in the form of full culms or splits. Boards and mats are also m ade from bamboo for building. Bamboo is maybe used as any one of the following building components: • Foundations • Framing • Scaffolding • Flooring • Walls • Roof • Trusses Fig 11.1: Example of Bamboo house Foundations For use as foundation, the bam boo poles are directly driven into the ground. They have to, however, be pre-treated for protection from rot and fungi. This prolongs the life of the foundation beyond that of an untreated bamboo pole. 32 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Framing Many rural and semi-urban areas, hardwoods are preferred to bam boo as framing of a building. This is because hardwoods provide better rigidity, which is interpreted as better strength and most hardwoods are better resistant to rot and fungi than untreated bamboo. There is also a certain amount of prestige associated with using hardwoods as they are more expensive and hence a potential symbol of wealth. However, in earthquake prone areas, bam boo is given higher preference because of higher resilience. Scaffolding Since ancient times, bam boo poles have been tied together and used as scaffolding. The properties of bamboo such as resilience, shape and strength make it an ideal mterial for the purpose. The working platforms for masons can also be built of bamboo. Flooring Fig 11.2: Bamboo scaffolding Earlier most houses had a floor of rammed earth raised above the ground a little with filling to prevent flooding due to drainage. Later houses had raised floors. This was more hygienic and had a serviceable area underneath that could be put to good use. Bamboo was used for this purpose. The higher resilience of bam boo culms m ade them better than conventional timber for floor beams. These would then be covered by either small whole culms, strips or bamboo boards m ade by opening and flattening out culms attached to the beams by wire lashings or small nails. 33 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. • Mat wall Mat walls are constructed by nailing a thin bamboo mat to either sides of a braced timber frame. These walls may then be plastered with cowdung, mud, sand or lime. Fig 11.4: Bamboo mat wall • Solid wall This wall uses full or split sections of bam boo side by side vertically in a frame. The wall may be made water-tight by cladding with closely woven mats. Roof Bamboo is used commonly as both framing and roofing. The following are the three most common types of bamboo roofing: • Bamboo tile roofing concave side up and the second layer interlocks over the first with convex side up. Though a very simple method, it can be completely watertight. The minimum pitch of the roof should be 30°. This is the simplest form of bamboo roofing. The culms are split into halves. The first layer of bamboo splits are layed the diaphragms scooped out and these run full length from eave to ridge. Fig 11.5: Bamboo tile rooting 35 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. • Bamboo shingle roofing Shingles are made from mature bam boo culms, typically 3-4 cm wide, and air-dried. These are attached to bam boo battens atleast 4 cm wide. The battens are tied or nailed to bam boo purlins not less than 7 cm in diameter. The F|g,, 6. Bamboo jh|ng|ej minimum pitch of the roof should be 30°. • Thatch roofing The roof is framed using bam boo purlins and rafters. The thatch is tied to this framing. Split bamboo is used to pin down the thatch at valleys and ridges. Trusses For the spanning larger distances in public utility buildings like schools, storage areas, commercial buildings, bamboo is utilized as a truss member. Bamboo has a high strength/weight ratio and hence is a good alternativve for roof framing. 36 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. An award-wining example of bamboo being used in modern day construction is the pavilion designed by Simon Velez, architect-artist-engineer in Manizales, Colombia. It was an exact replica of the EXP02002 paviliion desined by him in Hannover, Germany. He designed the pavilion with bam boo to take 7 feet plus of overhangs. He filled the joints with concrete to increase the traction strength of bamboo making it stronger than steel. He married organic and inorganic materials for a second time when he used bam boo fiber reinforced cement board for the roofing. The bamboo was Hg „ . 8: simon Velez pavilion of bamboo, protected from insects and pests by an age-old Japanese technique of "smoking bamboo". Besides the use of bam boo as a building material, there have been proposals in the past to use bam boo as reinfocement in RC columns, beams and slabs. One of the examples is a silo m ade of bamboo- reinforced concrete. This is the avenue for further research in the process of combining the ancient of bamboo building with modern materials like concrete. 1 Fig 11.9: Bamboo-reinforced concrete silo Fig 11.10: Bamboo reinforcement 37 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 12. Initial Assumptions and Calculations Based on data available from previous research by Francis E . Brink and Paul J. Rush (Feb 1966) certain calculations were made to estimate the required shear wall length, rebar spacing and bond length. The following values were assumed for calculations: Assumed values Steel Bamboo Allowable tensile stress 24,000 4,000 Unit bond stress (given) 150 50 Area of reinforcing, Av #4 bar = 0.19 0.216 Wail thickness, t 12" 12" The following table compares the results from the calculations performed using the above values for steel and bamboo Results Steel Bamboo Required spacing, s 16" I3 /," Required shear wall length in each direction, d 20’-4” 15’-8” Required bond length 22" 16" In the calculation of the required bond length for bamboo splints and additional Factor of Safety of 1.5 was assumed. This is to account for the fa ct that bamboo is non-uniform and hence will bond differently in the areas with and without nodes. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 13. Testing Needs The results from the previous chapter of “required bam boo rebar spacing", cast doubts over the validity of the value of shear strength assumed. Also due to the non homogeneity of bamboo, it was considered advisable to the results to verify the values. For this purpose the following tests were proposed to be carried out: I . Tensile tests - to determine the ultimate and allowable values for bamboo culms or splints. Crips for Holding Specimen Firmly' Force Measurement Fixed Head Test Specimen Fixed Head Thickness 1/8" Constant Rate of Motion Fig 13.1: Tensile test principle 2. Bond tests - to determine the strength of bonding between bam boo, mortar and brick. A testing mechanism similar to the one above can be used for performing a “pull test" on a sample. In this case a bamboo splint em bedded in mortar to test the bond strength. 39 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 14. Test Protocol This chapter describes in brief the test protocol adopted for performing the tensile and bond tests on bamboo. Tensile Test 1: Bamboo specimen with wooden supports According to the manual for Laboratory testing of bamboo, a bam boo specimen tested without supports is bound to slip out of the testing machine. It is, therefore, advised to make wooden supports for the bamboo specimen to provide better grip. Fig 14.1: Wooden support for specimen The supports were prepared according to the specifications in the Figure 14.1 from the manual. Figure 14.2 shows the specimen loaded in the tester ready for testing. Fig 14.2: Specimen loaded in fester HnM’ isometric view Cross sections 40 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Tensile Test 3: Bamboo specimen with no supports Test 3 aimed to test the bam boo specimen by itself, without any supports. Before starting the test. the bamboo specimen was just held in place in on the grip jaws. As the load was applied, the jaws the machine without applying too much pressure the grip on the specimen with increase in load. bit" into the specimen, automatically tightening Fig 14.4: Specimen with no supports loaded in tester Tensile Test 4&5: Bamboo specimen with single node Earlier tensile tests used a bamboo specimen with two nodes. Tests 4 & 5 were conducted to compare the difference in results between a specimen having two nodes v/s a specimen having a single node in the test length. Two tests were conducted with two such bam boo specimens. F ig 14.7: Single Node Test specimen 42 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Bond Test 2: Bamboo specimen embedded in brick pier In order to validate the values obtained from the earlier bond test and to simulate a condition similar to real-life masonry construction, the next specimen for the bond test was prepared by embedding the bamboo splint in a brick pier. The brick pier was prepared using standard red bricks used in masonry construction with the same mortar mix as the previous test (1:3 mix of cement to sand). The pier was allowed to set for 7 days before testing. The mortar was cured regularly during this period. Fig 14.10: Brick sample loaded in tester 44 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 15. Test Apparatus In order to test the modulus of rupture and bond strength of bamboo, the 5590 HVL series Universal Hydraulic Tester (for compression and tension) by SATEC Instron was used. The Civil Engineering Lab of University of Southern California provided this facility. The salient features of the tester are as under: • Load capacities range from 67,000 lb through 600,000 lb • Frame design features dual test space which eliminates the need to change fixing when performing both tensile and compression testing • Variety of crosshead styles permit easy loading of specimens • Variety of grip actuation options include: crank and pinion, lever arm, or hydraulic grip • Superior load cell technology increases accuracy and reliability of test result Fig 15.1:5590 HVL series Universal tester and computer for operation 46 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Frame Design A typical 5590-HVL frame includes a tension crosshead, adjustable crosshead, compression table, screw columns, notched columns, a protective piston boot, a load cell or nest of load cells, a cylinder and a piston. Ill 1 1 1 ! 1 1 iff ©oo Fig 15.2: Parts of Universal tester 5590 HVL series The dual test space design of a 5590-HVL system provides the capability of performing both tension and compression testing without changing fixtures. Tension tests are performed in the upper test space between the tension crosshead and the adjustable crosshead. Compression tests are performed in the lower test space between the adjustable crosshead and the compression table. Fig 15.3: Dual test space in Universal tester 47 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Along with these features the Universal Tester is also supported by 5500 Series Control Electronics and Partner software 5500 Series Control Electronics Instron's 5500 electronics allows accurate and advanced real-time control. These control the frame using any combination of load, strain, or speed rates. They also have automatic recognition and calibration of transducers to ensure safe and proper testing. The salient features of the Controller are 40,000 Hz data sampling, 500 Hz selectable data capture, 32-bit DSP technology, 1 9-bit resolution. User Control Panel Universal hydraulic testers include a modern user panel. Operators can perform important test control functions such as start, stop and return conveniently at the load frame. F ig 15.6: User control panel Partner software It is designed and written for the Windows® platform. Partner software allows easy multitasking of materials testing capability with the Microsoft® Office suite. Partner manages and automates the entire testing process from entering pretest parameters through report generation and distribution. Application-specific modules allow test technicians to quickly perform tensile, compression, shear, bend, or torsion 49 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. testing. Partner has networking capability, database structure, and built-in E-mailing capability allows users to share test results with other. Other tools used for the preparation of the test specimen are as shown below: • Bamboo Splitter The 6-way splitter is m ade of cast iron and used to split the full bamboo culm into splints. These splints were used as specimen for tensile strength tests or for embedding in mortar for bond tests. Fig 15.7: Bamboo Splitting method Fig 15.8: Splitter • Rubber mallet This hammer is used in conjunction with the splitter to split the bam boo culms. A rubber/wooden mallet must be used in place of a regular metal hammer to prevent dam age to the cast-iron splitter. * Fig 15.9: Rubber Mallet 50 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Tensile Test 2: Bamboo specimen fixed to wood supports Test 2a had the wooden supports glued to the bamboo specimen with an epoxy. The test failed due to cracking of the wooden supports and not the specimen. Fig 16.1: Failed support i i i i i i i i i Graph 16.2: Failure due to cracking of glued wooden supports 52 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 12000 10000 8000 8000 4000 2000 T e n s ile le s t 3 on Bamboo Specimen fwood tunaarM 0 > n — — - — C N P o s itio n (in.) Graph 16.3: Tensile test with doweled supports Tensile Test 3&4: Bamboo specimen with no supports The second set of tests was conducted with no supports for the bamboo specimen and using double node specimen and single node specimen. These were successful in both cases. The values were however, higher with the single node test as compared with the double node test. Fig 16.2: Failed Bamboo splint - single node and double node 53 m Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Bond Tests I s 1 set: Bamboo specimen embedded in mortar block and brick pier These were performed to check the bond strength of bamboo em bedded in mortar. The values were higher when the bamboo splint was embedded in a brick pier, as com pared with bamboo em bedded in a mortar block. But the sizes of both the splints and the area of mortar in which the bam boo splint was em bedded were different so there was actually no ground for comparison. B o nd Ted •suectsful s . t± i'W '* . ^ ^ < ■ j *> »i ' ■ > \ - ‘ - m m m m m f j \ S l& t t M s iW . . . . . - - , f j 4 - n E T i S U T y j . » « I J j X A Sijjsiaisriieisis' t 5 5 * j b ««s v * O' O' Q V O ' Q- O' O ' o ' o ' O' O' O p O ' O ' O ' o “ O- O ' O’ O' O ' O' P o s itio n (in.) Graph 14.6: Bond test with specimen embedded in mortar block 55 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. B on d tod with brick sample 140.00 160.00 S S » (« S > S S 5 iS s S K 140.00 'iTTii^i||i|iii|,|#d^i'111'ii['"iiimi1 Ti['iI"ii 'i|| « r« o 3 W S H ¥ S S S H ® « ! 12000 K S B fe S ^ S J p 100.00 m&f&mksetwmatx-sA 4000 - # 6 5 s fe « *a & « SSMg? ________________________ rr ■>wnT'?-,j .:?T - y- . v * r s S ^ i» < a f c S - ^ W - - w j o - •• ^ s e s 3 a ® i® ^ < t% © s«^ 5fer5E i*fei¥i3^ s? s g ^ jiy;'? i? ? iV : 60.00 - jK S g s s w 1 ?®^ ‘i . f ;. + ,'t - j - • ' • 'J T V • ,»f- v ? > i M C ^ - X L L v'-‘ .*;v .V .w ^ V -v - \ 7-_i>{' ~ ..« - ■ ’ —.- • \^ * i* U .r r l- «**■»-.-.’ ..,' • . . c?c^ ^ ^ ^ ffi* ^ * 4 * rJ * t* 3 i? < 5 ^ *}* *? f rf1 ^ Q* O* CK Or Cr O ' O ' O ' Op O* O* O ’ O* O’ O ' O* O ' O* O’ O1 O* O* i (in.) Graph 16.7: Bond test with specimen embedded in brick pier Bond tests - 2n d set: Comparative tests These were performed to compare all the parameters that affect the bond strength of bamboo in mortar. The first test was performed on bam boo specimen in equivalent mortar block to compare the results with bamboo in brick pier. This test yielded lower values than bamboo in brick pier. 56 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Comparison between brick sample and mortar block 180.00 180X0 140X0 fcjiW 120X0 J w S S m S & s ? 5 ^ J rE « B 100X0 r^Trg^r^a3afiS%* Mortar Block Brick Sample 5 80X0 : siXsitii « ® ifc rs .*i • IS lllg llj'S iy S i 80X0 - 20X0 Graph 16.8: Comparative Bond test with specimen embedded in equivalent area mortar block Comparison o f B o n d S treng th between presence and absence ol node m Without node With node f T » V ^ g S . £ ^ ^ .S b » X : Graph 16.9: Comparison of Bond Strength between presence & absence of node in mortar block 57 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 17. Computations For the purpose of guiding the layman about the step-by-step construction of bamboo-reinforced masonry, some basic calculations are required to estimate the amount of material required, bond strength etc. Unlike steel rebars, allowable tensile stress for bam boo reinforcement cannot be used to the maximum because the bam boo "splint" will fail long before in shear. Hence modulus of rupture is assumed as yield stress for calculation purposes. The following calculations are based on the values taken from tests and some values from the United Nations publication jointly prepared by D. Narayanmurthy and Dinesh Mohan of India (Narayanmurthy 1972) [noted with *]. Test results conducted for this thesis also yielded similar results (see chapter 16). Available Data: Bamboo: * Average modulus of rupture fy’ = 18,460 psi -* use fY ’ = 18,000 psi Allowable tensile stress, F a = 0.4 fy = 0.4 xl 8,000 psi Fa = 7,200 psi Allowable compressive stress F a = 0.4 x 18,000 Fa = 7,200 psi Modulus of Elasticity Eb = 2.2 x 10* psi Masonry: Masonry modulus of elasticity (per 1988 UBC) Em = 750 fm Asssumed specified compressive strength f m = 1500 psi For f’m = 1500 psi -»• E m = 750 x 1500 Em =1.125 x 10* psi Bond strength U u h =140 psi Allowable bond strength= Uu»/3 u = 47 psi 59 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PART I: CONCRETE SLAB Total dead load W = 308psf (1000 ff2)/1000 W = 308 k Base shear (to be multiplied by 1.5 per UBC, section 1628) V = 1.5 V = 1.5 ZIC W 0.4x2.75 308 = 0.275x308 V = 85 k Calculations: Thickness of wall = 12" Specified compressive strength of masonry, fm = 1500 psi rebar mortar brick Fig 17.2: Plan of wall Assuming masonry resists all shear Allowable masonry shear stress, F v = 1 .oVf7 ^ = 1.0Vl 500 F v = 38.7psi According to UBC section 1603.5, the stresses have to be increased by 33%. Therefore F v=l .33 x 38.7 = 51.47 psi. In case of non-inspected masonry, the maximum allowable shear stress is 50% of F v (m a x ) = 26 pSU... ................... (1) 61 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Rebar area - assuming 12 nos. of bam boo splints from a pole of 0 = 3" and wall thickness * %" (Refer table) A v = ■ 12 1 A v = — [2.16] = 0.18sq.in. Rebar spacing (Av x Fs) S = (Fv x b) 0.18x7200 26x12 = 4.15” =4" • (2) Fig 17.3: Full culm 1/12 th splint Fig 17.4:1/12* “splint” Required effective wall length d= V/(FvXb) =85x1000/(26x12] Use two walls in each direction (one for each exterior wall) L = d/2 + 4" (4" reinforcing cover on one side) L = 272.45/2 + 4=140.25 -> 140"/12 = 11.67’ d * 272.45" -i r-8" ' * "4 COVER Fig 17.5: Shear wall cover UseL= H ’-8" The above calculations are per UBC code and the UBC code is designed for a wall of nominal thickness of 7.625". By increasing the wall thickness, only load is increased and not base shear. Therefore, an adjustment factor can be applied as follows: Adjustment factor = 12 7.625 = 1.57 = 1.5. -(3) The spacing of the rebars and corresponding shear wall lengths can be increased by this factor. 62 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Therefore, Required rebar spacing = 4.15x1.5 = 6" Required shear wall length = 1 1 ’-8" xl .5 = 17’-6" The bond stress developed on the surface area of the bamboo splint em bedded in the mortar can be given by. Bond Stress, u = Tensile force Total surface area of em bedded splint fs x Av Perimeter x Bond Length Therefore, Bond Length,! = - fs x Av 7200 x 0.18 * 15" •(4) Perimeter x u 1.93 x 47 This means that each bamboo splint has to be embedded in atleast 15" of mortar at its free end. PART II: PITCHED ROOF Total dead load W = 190 psf (1000 ft*)/1000 Base shear (to be multiplied by 1.5 per UBC) ‘ ZlC W = 190 kip V = 1.5 Rw W V = 1.5 0.4x2.75 190 = 0.275x190 V=53 kips 63 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Calculations: 12" nominal wall, effective thickness = 12" Specified compressive strength of masonry, f'm = 1500 psi Assuming masonry resists all shear Allowable masonry shear stress. Rebar area, [From (2)] Rebar spacing S = (Av x Fs) (Fv x b) 0.18x7200 26x12 = 4.15"= 4" F v =26 psi Av=0.18 sq.in S = 4.15" Required effective wall length d= V/(FvXb) = 53x1000/(26x12] Use 2 walls in each direction (one for each exterior wall) L = d/2 + 4" (4" reinforcing cover on one side) -T-5" T-V d= 170" 4" COVER Fig 17.6: Shear wall cover L = 170"/2 + 4" = 89" -> 89"/12 = 7.42’ Use L= 7’-5” Using the adjustment factor of 1.5 from equation (3) Rebar spacing, S Shear wall length = 6” = 11’-2" 64 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Since the area of rebar, perimeter of the bar, tensile strength and bond strength dre the same, the bond length = 15" [From (4)] This means that each bam boo splint has to be em bedded in atleast 15" of mortar at its free end. Also horizontal reinforcement should be provided @ 0.07% of the shear wall area. Therefore, .. . t . 0.0007 x Thickness of wall x Length of wall Number of splints = ------------------------------------------- 2------------- Area of 1 splint 0.0007 x lZ ’x 12" 0.18 = 0.56 Place splints at every 2’ distance for horizontal spacing 65 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 18. Guidelines for building bamboo-reinforced masonry homes The guidelines for building will be divided into five main categories: 1. Calculation of required bam boo poles. 2. Purchase, transportation and storage tips (from earlier research by others). 3. Splitting & sizing techniques (standards previously established). 4. Treatment for water-resistance and insect/fungi resistance. 5. Building guidelines for: (a) Foundation (b) Walls (c) Windows & doors (d) Roof - pitched & flat slab 6. Precautions & forewarnings. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 1. C alculation of required bam boo poles To begin the process of building a bam boo- reinforced brick/cemenf block house, some basic calculations are needed to estimate the number of poles to be purchased for the purpose. Calculations for the spacing between bam boo “splints" (part of a whole bam boo pole/"culm "), with the strength of masonry (brick and cement block) taken into consideration, yield the following results. For a house of total floor area = 1000 sq. ft. R eqd . e ffe c tiv e length of shear w all in e a c h direction Min. required spacing b etn . splints C o n e . Slab (L=) Pitched roof (LP) C one. S lab/ Pitched roof 3 5 ’-0 ” 22’-4” 6” Using the above, one can calculate the length of shear wall required for one’s house by. Reqd. Length of'' Shear Wall in each direction -lc /2 or Lp/2- -Lc/2ortp/2- Fig 18.1 -Shear wall placement Min. Shear wall in each direction = L c or L P Wall A + B = L c or L P Wall C + D + E= Lc or L P Own house area (sq.ft.) 1000 X (Lc or Lp) Fig 18.2-Shear wall in elevation The shear wall length maybe subdivided into smaller lengths to suit the elevation but should not be made smaller than 4’. 67 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Lc/4 a lp/4 / / lc/4 oi lp /4 Upon calculating the length of TOTAL shear wall length required (A+B+C+D), an approximate number of splits required can ''Reqd. No.' of Splints for walls f Reqd. No.') of Splints for walls _ TOTAL shear wall length x 12 (Reqd. spacing for splint) (A + B + C + D)xl 2 * * * * * * * * * * \ I be determined as follows. N ote: The m ultiplication b y 12 is to convert the w all length dimension from ‘fe e t’ to ‘inches’. Also horizontal splints should be provided @ 2‘ distance. Therefore for a 9‘ high wall, 4 horizontal splints will be required. In case of foundation for the walls, at least 2 splints must be provided along the length of the concrete the footing. The total length of splints required for the foundation of a single story house can be roughly estimated from the adjoining figure. 'Total Length of splints forFoundn. = 2(X + Y).............. (2) Fig 18.3-Foundation rebars 68 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The Total number of bam boo splints required (for the walls, foundation, floors and collar beams) may be provided with a contingency of 2% to arrive at the final figure for required number of splints. Bamboo culms available in India are roughly of 3 different sizes - 3", 4", The adjoining table gives the number of the number of splints of V*' width that each of the culms can yield: : • — - 3 4" WIDE 03" - SPLINT Fig 18.4-Full culm and splint Upon deciding the species of bamboo to be used, the number of poles to be purchased can be determined by No o f poles Total no.of splints reqd N o.of splints for species selected Based on this calculation, one can buy the number of poles required for the project. Common Species of Bamboo used in bldg. t of culm No.of splints 8ambusa tulda & Dendrocalamus Stricta 3" 12 Bambusa Longispiculata 4” 16 Dendrocalamus brandisii 8" 33 69 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 3. Splitting and sizing techniques for the bam boo poles Bamboo to be used for the purposes of reinforcement is most effective in the form of bamboo splints due to increased surface area for bonding. The common tools used for splitting and sizing bamboo poles are: a. Cross-bars In this technique, crossbars of iron/wood (about 1" thick) are supported by posts set firmly in the ground. Some initial splits are opened into the edge of the culm with an axe. These are held apart by wedges and the culm is placed in position on the crossbars. The culm is then manually pushed/pulled to split it. b. Steel Wedaes These are used for splitting quartered culms. c. Mechanical splitters Mechanical devices can also be used for splitting the culms. These are more expensive but also more precise. Fig 18.5 -Crossbar splitter Fig 18.6 -Other tools tor splitting Fig 18.7 -Mechanical splitter 71 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 4. Treatm ent for w ater-resistance and insect/funai infection The recommended preservation technique for bamboo poles/splints used in construction is "hot-dipping" of air-dried culms. The cheapest and most-effective preservative is a mixture of coal tar creosote and fuel oil (50:50 by weight). 1% of dieldrin can be added to this mixture in termite-infested areas and 1% of pentachlorophenol can be added in areas of high decay. In this process, splints are immersed in a tank of preservative, which is heated either directly over a fire or through steam coils. The tank can be easily made by and cutting the cylinders into half and welding them together along the length. An alternative process is that “ pressure treatment". This process is found suitable for dry culms. The same preservative as mentioned above may also be used for the pressure process. There are certain other prescribed chemical preservatives like • Copper-chrome-arsenic composition • Acid-cupric-chromate composition • Copper-chrome-boric composition • Chromated Zone chloride These may also be used for treating the splints. Apart from these the splints should also be treated for water-resistance. Asphalt or coal tar emulsion is considered the best option to provide adequate water- resistance to the splints. However an excess of asphalt might reduce the bonding between the splint and the mortar. 72 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 5. Building guidelines This section is aimed at providing the homebuilder with basic information about using bamboo splints as reinforcement in masonry construction. It is divided into 4 parts: a. Foundation The foundation for a bearing masonry structure should be a continuous bed of at least 1:2:4 mix of concrete (cement: sand: aggregate). The width of the concrete bed required can be calculated as under: • One story residence - (Wall thickness + 4") • Two story residence - (Wall thickness x 2) The depth of the footing from the top of soil/ground should be kept at a minimum of 2’ to get adequate anchorage into the soil. The minimum thickness of the concrete bed is given by [reqd.bond length for bamboo" Miathickness = + 3" cover = 15"+3"= 18- In case of inadequate thickness of the bed, additional reinforcing may have to be tied in at 90°. win. 2 5 * JPliCE GJFQUHO lEVEl -SENT SEINEORCE- •MENf FO* 'NAQEGUAfE OEPTH w in . r Fig 18.8 -Section thru' foundation 73 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. It is advisable to have atleast 2 splints in the longitudinal direction of the concrete bed as reinforcement. The splints should have a cover of atleast 3". The dowel bars should have an overlap of atleast 25" with the wall reinforcement splints. b. Wall: After pouring the concrete bed and curing it for the requisite period of time, one can start with construction of the wall. For wall building, it is advisable to use a mortar mix of 1:6 (cement: sand). Appropriate grade of cement should be used to get desired strength of bonding. Wall construction may be of two main types- solid wall and cavity wall construction. i) Solid wall construction This is the most common wall type for the unreinforced type of masonry construction. It is, however, highly difficult to adapt this kind of wall construction for reinforced masonry because of the likelihood of high wastage of bricks. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ii) Cavity wall construction: This is a more feasible option for reinforced masonry. The adjoining figure shows the “stretcher bond” which is the typical brick bond used for cavity wall construction, as there is minimal wastage of brick. Fig 10.9 -Stretcher bond • -------------- B A M B O O SPLINTS During the construction of a cavity wall, care should be taken to ensure that the width of the cavity is atleast 3” to ensure proper embedding of bam boo splints in the mortar. According to calculations, the maximum spacing between the splints required to get the optimum performance out of the bamboo splints is 6” on center in both the horizontal and vertical direction. The adjoining isometric gives a good idea of the construction of a cavity wall and spacing of splints. The two sides of the cavity wall should also be is. connected to each other by using metal or ® bamboo ties. J '-'O .C . M O R TA R *— ----------- + F ig 18.10 -Plan of cavHy wall Fig 18.11 -Isometric view of cavity wall i - METAL/BAMBOO T IE S Fig 18.12 -Section thru' the wall 75 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. b. Windows and doors During wall construction, certain special precautions are to be taken into consideration are required to be made about providing reinforcing around the window and door openings. The UBC code requires that a reinforcing bar is provided on top of doors and windows have a bearing of atleast 24" into the adjoining masonry. Vertical reinforcing bars must also be provided on either side of the openings. -24’’- ' Fig 18.13-Reinforcing around window '-2 4 " ' '-2 4 ’’-' c. Collar beam & roof For better seismic safety of reinforced masonry structures, it is advisable to provide a collar beam of concrete at the top of the wall before the roof is constructed. The collar beam binds the entire masonry wall into a frame and makes it better resistant to seismic forces. It is advisable to use a 1:3:6 mix of concrete for the collar beam. The required depth of the collar beam can be calculated as under Reqd. depth of collar beam = Min. bond length of splint +1 ’ = 15"+1"= 16” Fig 18.14-Reinforcing around door 76 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The collar beam can be provided in two ways as is illustrated in the adjoining figures: i) The first option tops the brick wall with a concrete collar. This option is easy to cast, but not very aesthetically appealing to the eye as an elevation feature. ii) The second option involves casting the collar in the cavity of the wall. The process of casting this collar is more cumbersome but it is more aesthetically appealing. The roof may be pitched roof with tim ber/bam boo purlins and tiles or concrete slab. Depending on the type of roof, the spacing of the reinforcement splints and length of shear wall required will change. It is also advisable to use timber or bamboo trusses for supporting the pitched roof to provide additional stability. F ig 18.15 -Collar beam above wall 'C O N C . C O IL A I fig 18.15 -Collar beam in cavity 77 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Cost comparison Assuming the current rates of steel rebars and bam boo splints, a comparison between the cost of using steel rebars v/s using bam boo splints yielded the following results fro a 1000 sq.ft of house. 4 2 0 400 350 300 a GO Z J C © < J •c a. 150 100 50 0 250 200 Cod Comparison between steel and bamboo reinforcing (for 1000 sq.(l house) Steel rebate Bam boo Splints Category Rg 19.1: Graph comparing the cost of steel rebars v/s bamboo splints The graph clearly highlights the cost advantage of using bamboo as reinforcing in bearing masonry. Though, bamboo might not be a good alternative for high-rise structures, for single or double story structures, commonly built by lower-income communities in India, it is a worthy alternative. 78 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Ill Conclusions & Further Recommendations The tests conducted for shear and bond stresses during this thesis show contrasting results. For better shear resistance, larger area of bamboo splint is preferred and for better bonding, lesser splint area is advisable. In order to strike a balance, a set of possible results has been provided for the benefit of the user. Depending on the available labor expertise, a suitable result can be chosen and used in the building. This thesis concludes that it is possible to use bamboo splints as reinforcing for masonry structures. Thought the tensile strength of bamboo is about l/3 rd that of steel, this is sufficient for masonry structures and provides a more economical and environment-friendly alternative that is accessible to every section of the society. However, there is still ample scope for research on the subject. Further research may be conducted to determine the following: ■ Splicing length for bamboo splints. ■ Factor of Safety to calculate allowable stresses of bamboo to be used in calculation. ■ Adaptation of calculations and guidelines to the Indian Standard Code. • Economical and mechanical splitting methods for bamboo culms. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Bibliography Amrhein, James E.(1998) Reinforced Masonry Engineering Handbook-Clay and Concrete Masonry California: Masonry Institute of America, 1998 Narayanmurty, D. & Mohan, Dinesh The Use of Bamboo and Reeds in Building Construction New York: United Nations Publication, 1972 Schierle, G G (1996) Lecture Notes on Seismic Design, USC California: USC, 2001 Vitra Design Museum / ZE R I /C.I.E.R.C.A Grow your own house Websites Bhatia S.C. A probabilistic seismic hazard map of India and adjoining regions <http://seismo.ethz.ch/gshap/ict/fig 1 .gif> British Geological Survey, Seismicity of Southern Asia fabove magnitude 3.0 Ms) <http://www.gsrg.nmh.ac.uk/images/southern_asia_seismicity.jpg> Indian Meteorological Department, List of some significant earthquakes in India and its neighbourhood <http://www.imd.ernet.in/section/seismo/static/signif.htm> Mukherjee, Abhijeet A Novel Rehabilitation Technique for RCC Structures Affected in Gujarat Earthquake <http://www.civil.iitb.ernet.in/-abhiiit/Rehab.htm> Murty, C.V.R. Preliminary field report on Gujarat Earthquake <http://www.icionline.com/mar01_earth.htm> Shaw, Rajib Bhuj Earthquakeof January 26, 2001-Consequences and Future Challenges < http://www.edm.bosai.go.jp/lndia2001/Surveyl /report_e.htm> 80 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

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Asset Metadata

Creator Iyer, Sreemathi (author)

Core Title Guidelines for building bamboo-reinforced masonry in earthquake-prone areas in India

School School of Architecture

Degree Master of Building Science / Master in Biomedical Sciences

Degree Program Building Science

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Architecture,engineering, civil,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Schierle, G. Goetz (committee chair), Schiler, Marc E. (committee member), Xiao, Yan (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c16-295046

Unique identifier UC11341531

Identifier 1411790.pdf (filename),usctheses-c16-295046 (legacy record id)

Legacy Identifier 1411790.pdf

Dmrecord 295046

Document Type Thesis

Rights Iyer, Sreemathi

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA