As~Vol I, May 2011

Bulletin

A Monthly Newsletter

Association of Structural RehabilitationC-2099, Oberoi Garden Estate, Chandivali, Andheri-E, Mumbai-400072, Tel: 022- 2857 5786, Email: info@indianastr.comweb: www.indianastr.com, Societies Reg Act , Public Trust’s Act Reg no. F-39736no. 1216

Tool for Rehabilitation

The Committee Members

President:

Chairman:

Secretary:

Jt. Secretary:

Treasurer:

Organising Secretary:

Public Relations:

Coordinators:

Dr. G.R. Reddy,

Prof. K.M. Bajoria,

Dr. Gopal Rai,

Prof. A.K. Singh,

Dr. M.K. Kamat,

Naresh Sanghvi

Mr. Akanshu Sharma,

Mr. Sandeep Ranshur

Mr. Vrijesh Sharma

Mr. Yogesh Indolia

BARC

IIT Bombay

R & M International

Bhagubhai

Krishna ConChem

BARC

Bhagubhai

R&M International

21 SHM Consultants

Consultant

Local ChaptersMaharashtra

Mangalore

Bengaluru

Goa

President:

President:

President:

President:

Prof. B.N. Pandya

Prof. K. S. Babunarayan

Dr. R. Ramesh Babu

Mr. Madhav N. Kamat,

Emritus Prof. SPCE

NIT Suratkal

CPRI Bangalore

M.K. & Associates

Secretary:

Secretary:

Chairman:

Vice-President:

Dr. Abhay Bambole

Dr. Katta Venkatramana

NIT Suratkal

Shri B. N. Nagraj

Dr. C.S. Gokhale

Prof. and HOD, SPCE

Binyas Contech Pvt. Ltd.

Goa College of Engg.

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As you all know that one hand aged structures are becoming threat to the nation and to the life of thepeople. The problems are more sever in the case of RCC structures. There are large numbers of structures beingcollapsed every year under normal loads. It is very difficult to quantify the loss both in life and economy when theaged structures are subjected to natural events such as earthquakes. This is also true in some of the new structures.On the other hand we have technology which helps to make the nation very safe. The difficulty is that one way thetechnology is not transferred to the need in simple and adoptable means. Other way is that the public awareness ofthe technology is minimal. Some times it is an assumption made that the cost of repair or retrofitting is veryexpensive. More times the technology is applied in ineffective way.

To take care of these gaps a group of Engineers of India have formed Indian Association of StructuralRehabilitation ( ASTR) which will work towards achieving excellence by delivering Engineering Services for any kindof Civil Engineering Structures meeting need based rehabilitation requirements. Indian ASTR got registered and isa non governmental, non profitable and social association. Some of the objectives to be met by the association areas follows.

Cater to the need of sick Civil Engineering Structure with Assessment & Diagnosis in a Scientific &Technical manner.

Evolve a unified standard practice in Structural Rehabilitation Engineering for Assurance of Quality basedProfessional Engineering Services.

Share the knowledge, expertise and experience of Structural rehabilitation through publications.Create and sustain atmosphere of Correct Engineering Practice.Develop competency of Technical Persons through Training and Continuous Education program to inculcate

right Attitude, Approach & Behavior.Earn the Confidence, Approval & Appreciation from Society and Nation.

To fulfill the objectives, research community, designer community, industrial/application community andadministrative community need to join the hands. There is large gap among these communities. The appliedresearch should be on need based and researchers need to understand the industrial/application communityrequirements. There should be good interactions between the designer and the researcher to see the new researchwork is completely understood and applied through industry and administration.

To initiate interactions among all of us and to fulfill the objectives, the association has initiated publishingbulletins. The first volume is with you and you are requested to read it and raise questions if any and also requestedto contribute articles for the bulletin.

Looking forward for your positive and active participation to serve the nation and take it to the level ofdeveloped countries

With best wishes

a.

b.

c.d.e.

f.

Dr. G.R. ReddyPresident ASTR

Presidents Address

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About Prof. Kamal BajoriaProfessor, Dept. of Civil EngineeringIIT-Bombay

He completed his B.E. Civil from nagpur university with gold medal in 1980. Then he didMtech in structures from IIT Bombay in 1982 where he was awarded Batnagar award fortopping in class. Subsequently he did his Ph.D from Cambridge University, USA.

As a working professional Prof. Bajoria started as a technical assistant and researchassociate at Cambridge University along with his Ph.D.In the year 1987 he joined IIT Bombay as a Assistant professor. In 2005 he became AssociateProfessor in 2005 and subsequently became Professor in 2011.

Prof. Kamal Bajoria has more than 25 papers in refered international journals andconferences. He has also won many awards and during his student and professional life.

Prof. Kamal M. Bajoria,Chairman

Professor of Civil Engineering Department, IITBombay, have been appointed of ASTR with effect fromMarch 2011.

Appointmentof Chairman

Past Events

Annual General Meeting- AGM

On 28th August 2010, AGM was organized at sardarpatel college of engineering. All the organizingmembers and members were invited for themeeting.

Engineers Day, Mhada4th October 2011,Karamveer Dadasaheb GaikwadSanskritik Kendra.

Mhada with ASTR organized Engineers Day andWorld Habitat day. The function attracted Peoplefrom Bodies from public sector like MMRDA, MSRDC,MCGM etc.

Engineers Day, MCGM30th September 2011,Yeshwant Natya Mandir, Dadar

Mumbai Municipal Corporation organized EngineersDay for appreciating the spirit of engineers.Manyrenowed consu l tant s , cont racto r s , c iv i ladministrative officers and Public Bodies took part.The function saw a large crowd to celebrateengineering

Special lecture and Talk, IEIMumbai15th October 2010

A lecture on “Pushover Test on Prototype RCCBuilding at CPRI, Bangalore” at Institution ofengineers MSC, Mahalaxmi by our president Dr. G. R.Reddy. This lecture was the first event organized by IEIMumbai Centre. The event was also supported by 21SHM Consultants, Mumbai as sponsors.

Felicitation of Prof. B. N. Pandya.26th March 2011

Our Maharashtra chapter president Prof. B.N.Pandya recently got retired from his service as aprofessor in Sardar Patel College of Engg. A one daySymposium on Finite Element Method was organizedin his honour at SPCE.

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Forthcoming Events

“National Conference on Repair and Rehabilitation of ConcreteStructures” at Power Management Institute, Sector 16A, Noidaon 6-7th May 2011.

The Conference is jointly organized byand

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Indian Concrete Institute, IndianAssociation of Structural Engineers Association of StructuralRehabilitation(ASTR)

Themes:Condition Assessment & Distress- Diagonastic TechniquesCause of distressRepair Rehabilitation and retrofitting techniques for buildings, bridges, dams etc.Material for repair, rehabilitation and retrofitting.Durability, Serviceability and economyNew techniques and materials for repair/ rehabilitation/ retrofitting and their life cycle

evaluation.Long term health monitoring of structuresCase studies

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Workshop on Rehabilitation and Retrofitting of Structures, 2011

After grand success of the first workshop in IIT Bombay, The next editionwill be held this year and the dates and venue will be announced soon.

The Proceedings of the first edition of WSRR is available. To get acopy kindly contact ASTR coordinators.

Cover

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Structural Strengthening of ROB, JNPT, Navi Mumbai

Case Study

Introduction:Port at Nhava-Sheva, Navi Mumbai is managed by Jawaharlal Nehru Port Trust (JNPT). This port which isone of the busiest port and handles about 70% of container traffic of INDIA has constructed Rail overbridge at Karal Junction for efficient traffic flow. The construction of this bridge was completed andopened for traffic since 1991. This bridge consists of 36 spans of varying lengths with 37 expansion joints.The total length of bridge is 700 m.The Rail Over Bridge at Karal Junction has heavy traffic movement due to which it had started showingsigns of distress.The bridge was functionally designed for crossing railway line and was structurally designed for IRC 45Rloading. As per the revised recommendations of IRC and prevailing practice, the bridge is now requiredto sustain IRC Class 70 R loading.

1. Expansion joints were not functioning properly. In the original design there was no provision ofappropriate expansion joint.2. Slab area of expansion joint was found to be damaged severely due to heavy vehicular movement.The gap between two spans has become significant and concrete had deteriorated.3. The neoprene/elastomeric bearings provided in bridge were inadequate for heavy vehiclemovements. They appear to be bulging out and damaged.4. There was a visible sag in the superstructure in many spans. The typical structural failure cracks in thegirders were observed.5. The new expansion joints could not last long due to excessive vibrations and the poor quality of deckconcrete at the end of span.6. The substructure/piers appeared to be sound.

Some distress are shown in Fig.1 and Fig.2 . The major observation duringthe site visit are as follows.

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Contributers:Prof. R.S. Jangid,

Prof. Abhay Bambole, and

IIT Bombay

SPCE

Dr. Gopal Rai, R & M International

Fig 1: Cracks on Girders Fig 2: Slab sagged

In view of above observations it seemed that the structural health of the bridge was not very good. Theproposed strengthening measures for the bridge by the consulting team are as follows. (Fig 3)

1. Strengthening of girder by steel truss system-The girders and slabs are to be strengthened by placing additional steel truss systems which will supportthe bridge deck/slab/girders with M32 high strength bolts. This was designed to take about 50% of loadcarrying capacity of girders.

2. Replacement of bearings-The existing neoprene/elastomeric bearings should be replaced by new elastomeric bearings. Shore-a-hardness hardness of rubber material used should be 60.

3. Provision of new expansion joints-It was recommended to replace the expansion joints with Wabocrete Strip Seal Expansion Joint System.It is a superior joint system, which can be rapidly installed in failed expansion joints and also is suitable forheavy vehicle bridges.

4. Pre-Stressing using C-fibre Laminate and Carbon fibre wrapping of girder and slab :-To further increase the structural strength of the bridge, it was recommended to strengthen the bridgeusing the carbon fibre composite wrapping around the girder and slab. At the bottom of each girder 3Pre-stressed Carbon Fibre Composites (CFC) laminates i.e. 2- 80/1.4mm and 1- 50/1.4mm was proposedto be placed. The load to be given to prestressed laminates should be 8-9 tons. The deck slab was alsorecommended to be strengthened by putting CFC laminates 80/1.4 at 50 mm c/c at the bottom. Theproperties of required laminates and wrap were specified.

Steel Girders Bearings Replacement Pre-stressed Laminates

Carbon Fiber Wrapping

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Steel Girder Fabrication Approach Slab Casting

Fig 3: Rehabilitation Process for Bridge

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NDT on Superstructure ConcreteTwo type of non-destructive test have been performed on the bridge superstructure are to assess qualityand in-situ strength of concrete are presented below:1. Testing of Bridge girder using UPV (Ultrasonic Pulse velocity) to on obtain quality of concrete. All thegirders will be tested at minimum 3 locations on each under direct transmission.2. Testing of Bridge girder using Rebound hammer to estimate the characteristic strength of the girderconcrete. All the girders have been tested at minimum 12 locations on each (6 locations on each faceof the girder).

4) Shear strains have been measured with the help of foil type ElectricalResistance Strain gages mounted on the side face (vertical) of the two girder, near the support theoriented at 45 to the beam axis. Two gages per span have been used for measurement (girder No. 1-LHSand girder No. 5-RHS) for standard loaded vehicle positioned to induce maximum shear. Change inshear strains values before and after rehabilitation indicates the strengthening effect with regard toenhancement in shear stiffness of girders.

Measurements on Superstructure to Assess Effect of RehabilitationFive different types of tests have been performed on the bridge superstructure to assess effect ofrehabilitation (before and after) and presented below (Fig 4):1) Deflection has been measured with the help of Linear Potentiometersmounted at centre of the girder on bottom face. Four sensors (Girder Nos. 1, 3, 5 and 7) have been usedfor measurement with standard loaded vehicles positioned to induce maximum deflection. Change indeflection values measured before and after strengthening is the primary indicator of the strengtheningeffect.2) Flexural strains have been measured with the help of foil type OmegaType Transducer at the centre of girder on bottom face. Two Transducers have been used formeasurement with standard loaded vehicles positioned to induce bending moment. The change inflexural strain values indicates the strengthening effect with regard to enhancement in flexural stiffnessof girders.3) Change in crack–width have been measured with thehelp of omega type Displacement Transducers (strain gage based) mounted on the side (vertical) faceof four girders oriented perpendicular to the diagonal shear cracks. Four sensors have been used formeasurement (Girder No. 1-Right Hand Side (RHS), 3-Left Hand Side (LHS), 5-RHS and 7-LHS) withstandard loaded vehicles positioned to induce maximum shear. Change in crack width indicates thestrengthening effect with regard to enhancement in shear stiffness of girders.

Measurement of Deflection:

Measurement of flexural strain:

Measurement of shear strain/crack-width:

Measurement of shear strain:

Instrumentation and Testing of BridgeThe purpose of the instrumentation is to obtain reliable and consistent measurement of the various keyparameters such as deflection, strain and vibration of the selected bays of the bridge. It is envisagedthat due to strengthening and retrofitting, strains and deflections of the girders shall be further reduceddue to application of standard static loads. Besides, there would be reduction in vibrations as well duringapplication of dynamic load. Extensive measurements of all these parameters are proposed to berecorded before and after strengthening. The various measurements to ascertain strengthening effecthas been presented below.1. Measurement of strain, deflection and vibration of three spans of the Rail Over Bridge of JNPT at theidentified locations under the static and rolling load before rehabilitation/retrofitting.2. Measurement of strain, deflection and vibration of the three spans of the Rail Over Bridge of JNPT atthe same identified locations under the same static and rolling load after retrofitting.Besides this, to estimate condition of concrete in existing structure, Rebound hammer tests andUltrasonic Pulse Velocity (UPV) tests were also proposed before strengthening.

5) Frequency of vibration of girder has been measured with the helpof piezoelectric accelerometers mounted at centre of the two girders on bottom face in midspan position. Four piezoelectric accelerometers sensors have been used for measurementwith standard loaded vehicles moving at 25 kmph. Frequency measurement will also indicateof the strengthening effect with regard to enhancement in overall stiffness of girders.

Measurement of vibration:

The procedure followed for taking measurements on each span before and after strengthening isexplained in the following paragraphs.Standard vehicle having distance of 3.1 meter between front and middle axel and 1.4 meter betweentwo rear axels and weighing 32 Ton each (average weight) were used for loading each span before andafter strengthening. Six different static load cases and two dynamic load cases were consideredmeasurements. Two standard vehicles have been placed side by side for static measurement. Standardvehicle in Load Case -1, generates maximum shear stress on main girders near support B (towards JNPT)of the span for east side carriageway.Dynamic load cases were recorded with an initial no load signal for ambient vibrations, if any. Vibrationsignals were recorded on multi-channel vibration recorder and analyzer, for load case A. Similarlyvibration signals were recorded for load case B.

Acknowledgements:

We would like thank authorities and engineers of Jawharlal Nehru Port Trust, for their co-operation.Special thanks are due to Shri. N. Deshpande, Manager –I, Port Planning and Development (PPD)Department, JNPT and Shri. R. R. Gaikwad, Asst. Manager PPD Department, JNPT, for their support andco-operation during the work which is being carried out of Karal ROB, Nhava Sheva.We would like to thanks Bluestar Const. Co. for there support in providing infrastructure and localassistance. We are also thankful to Sanfield india for supporting and working with us.We would also like to thank Dr. B., N. Pandya, Head, Structural Engineering Department, for support intesting the bridge.

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Fig 4: Different Sensors. Namely (L-R) Omega Transducer, Linear Potentiometer, Strain Gauge

Fig 5: The Data Acquisition system for taking testing data (Static and Dynamic)

“ASTR” Member List

P.B. NemadeVasantha PremrajSanjay Deoram MahajanSharad M. DhopeDilip Dhondu GarjeKatwate Kishorekumar LaxmanraoRekha Mangulal PathareSalunkhe Shivaji BhausahebPawar Pradip BaburaoSurendra Kumar ChoubeyBharat H. JankoliKumbhar Pandit ChanduramSadanand Laxman PagdhareSatish LohokareSanjay Jagannath JadhavYuvraj Shivraj NakhadeKelgandre Kishor BalasahebDr. Wayal Abhaykumar ShivajiraoSawant Sanjay MahadevHrikesh N. AherYogesh SinghDeepa A. JoshiAmrutlal Laxmidas ArdeshanaNemichand Ghewarchand BogawatSalim A. JawadwalaDr. Urmil V. DaveAbner Manuel RodriguesShenvi Nilay N.Sharang Vaman TotekarOmkar A. GaitondeBappi T. GoraiShet Marathe Neha AudhutRamanand Raghunath DesaiTanvi V. KeniRayesh Ratnakar RaikarTanmay Tushar UsgaokarRaisa Ninoshka MesquitaKamlesh Shashikant DalalSuresh Manubhai PatelDr. H.S. PatilDr. C.D. ModheraDr. Atul K. DesaiS.N. DesaiPatel Ramjibhai T.Dr. S.A. VasanwalaAshok Kumar J ShahPatil Yogesh DeoramGaurang R. VesmawalaAnant M. ParghiMayank DelwadiaSurwanshi Shiwanand RohidasSailesh Ramanlal MahimturaDr. C.S. GokheleJitendra GaonkarJennifer Lewis E. KamatMadhav N. KamatUlhas G. SawaikarSunil Bhikaji BhadangeShriram Gajanan BapatJayant Anant KulkarniVasaikar Hemant BabulalPatil Dnyanraj MarutiraoSuresh M. AhujaShubhash Yashwant DalviAnil Kumar SachanVivek Ganesh AbhyankarPriti A. Patel

Karvekar Arvind VishnuDr. S. ShanmugamDr. V. G. ShrisanthiMohite Santosh ShankarJaydeep Mohanrao ShindeSarita R. KhotAmit Raosaheb ChaughlePimple Rohit PromodUmesh SinghAvinash Prakash PanhaleSnehrox R. DeoreLaxman Tejbhadur GuptaVenkatesh Rajan IyapillaiSurjit YadavMuke R. Y.Dr S. D. BhartiDr A. A. BageKame Ganesh ShamraoPrasad Moreshwar GharatDr. Mohan M MurudiPankaj P. BhosaleAshok B. KarpeNamdev Pandurang ManePrakash Bahnudas AwalkarRajendraprasad Dattatraya MakaneSunhash Ramkrishna ShindeMangesh Ramchandra JagushteVaity Navneet M.Taware Mangesh DnyondeoAbhishek Raminiklal JainUsha S. KarthaS. Robert RaviSudhir Bhagwat NimbalkarDilip GangadharanZope Purushotam EknathK. GiridharChandan K. ParabDr. Jagdish G. KoriR. B. RathiNitin S. Sonar

Tanuja P. BandivadekarSandanand S. ShettyPuneet GuptaProf. Ganesh HegdeSayeed SulaimanRavi Kumar C.K.Arun Kumar S. N.A. RamchandranPankaj Subhash ShahAlpesh Ramesh ChutaliaJain Shantilal H.Dr. Mahendra Kumar ShrimaliArun SohaniJayesh KothariNagraj T. ChinivarG. R. ChahalDeepak G. Nihalaney

Kailas Natha ThoratShaahank Chandrakant GharatRajendra Murlidhar JoshiKiran Bansidhar BochareT. Kishor KumarKanhaiya SinghRajiv NayanP. ManoharanR.B. Sastry

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K. S. BabunarayanKatta VenkatramanaM. H. PrashanthH C Chinnagiri GowdaShamir RDevraj ManaiSathyaranjana Rao MK Anil HegdeSudhir Bhandarkar BP Ekanath DandekeryKenet D'SouzaS K Anand KumarSathish BBabu M BhajantriShantharam PatilM Gopal BhatH M MahendraChandrashekhar ARajendra KalbaviAnand R BandageAnil V Baliga MKeertan KumarM C NarasimhanK T Prakash AlvaAnand Bhat HRajesh D MaistryU Raviprasad UpadhyayaSuresh Pai PHarsha UrvalGopinatha NayakPremanand ShenoyD C VirupakshaVijaya Vishnu Mayya TC J LoboR ShivashankarBalasubramanya MVimal Keethi JainSubhash C YaragalR. Ramesh BabuB. N. NagrajD. Kotresh PrabhuV. Srinivasa MurthyK. R. Sunder KumarK. ChethanBalasaheb Shivaji ToraskarAniket Arun KadamJayshree Shantaram ChawhanKishori J. ThakurManoj KothariSameer JoshiMridul GoyalViral JasubhaiMehul ParikhImran M. MerchantPatil Suresh JanardanRameshwar SharmaRai Nishant KishorAjay ShiroleV. S. PanikanthKulvinder Singh SagguPadmakar Kodavati GantiProf. A.K. SinghDr. Madan KamatDr. R. S. Jangid

Chetan KhnnaGaurao D. PokaleMahindra Ashok MokalProf. Sangeeta GadveAman DeepDr. Mukund R. ShiyekarProf. Hanamnt Shamrao JadhavPatil Pandurang ShankarMehta Vaibhav AshokkumarVineet JainShivaji Krishna WandreProf. V. JothiprakashMushtaq AhmedDeepak K. ShahM. M. AcharekarAshok C. DaryananiAtul T. DesaiBinu R. PatelBhosle Suraj UttamraoPatil Leena SudhakarNilekha Digambar MhapsekarPathan Mohsin M. K.Khedekar Sahim A. R.Narendra Swamy KoppulaPulari Satish NarayanraoYadav Manish BhalchandraSagar Sadanand PatilChoudhary RupeshPunit GoelP. R. RoyVikas Prakash GholapAjay SharmaMadhekar Suhasini M.D. S. JoshiDr. B. N. PandyaHitesh C. ChotaliaDr. C. NatrajanSuhas Pramod BhaveDr. Kapilesh BhargavaRishee R. BhatiaAshok G. PatelC. J. RaoDr. Abhay N. BamboleDr. A. K. DhawanHemanshu M. ShahD. N. NagrajA. Raffi MohamedKalyan Barta RoyAjitkumar R. KanteliaAtul B. SinghSatish Kumar SainiPradeep AgarwalAshok C. NaikV. VenkatrajUpendra Kumar SinghGautam ChatterjeeSantosh BhiseYogita M. ParulekarDisha Rajendrabhai MistryNiddish Gunawat ShahIshan Rahul ShahVinod B. VanvariRedij Dashrath ShriramSandeep Narayan RanshurK. P. Jayateerth

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ASTR Member List Contd.

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