इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 10434-1 (2003): Installation, Maintenance and Observation of Deformation Measuring Devices in Concrete and Masonry Dams - Guidelines, Part 1: Resistance Type Jointmeters [WRD 16: Hydraulic Structures Instrumentation] “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda ““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee”” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 10434(Part 1) :2003 *m Tiwl-w, hwT* (-dww WFTmf * IJI I mTliMmw%it@’n ( H7TJpl%wr) Indian Standard INSTALLATION, MAINTENANCE AND OBSERVATION OF DEFORMATION MEASURING DEVICES IN CONCRETE AND ! MASONRY DAMS — GUIDELINES . .. *,.* PART 1 RESISTANCE TYPE JOINTMETERS ..s . *62 First Revisio; ) ( ICS 93.160 0 BIS 2003 BUREAU OF IN DIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARC l NEW DELHI 110002 April 2003 Price Group 6 Hydraulic Structures Instrumentation Sectional Committee, WRD 16 FOREWORD This Indian Standard (Part 1)(First Revision) was adopted by the Bureau of Indian Standards, after the draft finalized by the Hydraulic Structures Instrumentation Sectional Committee had been approved by the Water Resources Division Council. To minimize cracking, large straight gravity and arch gravity dams are made in blocks, separated from each other by transverse and longitudinal contraction joints. To restore the dam to its monolithic state for integrated behaviour, contraction joints are grouted with cement grout. Grouting of joints is done when the joints have opened tomaximum. Measurement ofjoints movement during grouting operation will indicate how much grout should be pumped into the joints. Measurements ofjoint movements subsequent to the completion of the grouting of contraction joints, provides information regarding the behaviour of the grouted joints. Surface measurements and joint movements will be useful for watching shearing movement of joints. These measurements can bedone with mechanical strain gauges applied togauge inserts. However, full reliance cannot be placed on the surface measurements as all parts ofjoints do not open at the same time and not even the same amount. Internal joint movement may, therefore, also need to be measured. Vibrating wires type jointmeters for measurement ofjoint movement at the surface and in the interior of concrete and masonry dams are being separately covered. This standard has been published in two parts. Part 2of the standard covers foundation deformation measuring devices. This standard was first published in 1982. This first revision is being taken up to incorporate the knowledge gained during the use of the standard. In this revision reference clause has been added and some addition has been made in the method of installation of resistance type jointmeter. The composition of the Committee responsible for the formulation of this standard is given at Annex E. IS 10434 (Part 1): 2003 Indian Standard INSTALLATION, MAINTENANCE AND OBSERVATION OF DEFORMATION MEASURING DEVICES IN CONCRETE AND MASONRY DAMS — GUIDELINES PART 1 RESISTANCE TYPE JOINTMETERS First Revision) ( 1 SCOPE One 450 conical contact point is attached to each member. For taking measurements the conical points This standard (Part 1)covers the details ofinstallation, are inserted into the inserts fixed in the drilled holes maintenance and observation of resistance type defining apredetermined gauge length. The essential jointmeters of tie embedded type for measurement of features of the instrument are shown in Fig. 1A. joint movements at the surface and in the interior of concrete and masonry dams. NOTE —The gauge isavailable intwogauge lengths (254 mm and 508 mm) and appropriate gauge suitable for the given 2 REFERENCES situation should beused. The following standards contain provisions, which 3.1.2 Inserts through reference in this text constitute provisions of Inserts may be made ofmild steel orstainless steel, but this standard. At the time of publication the editions stainless steel inserts are recommended though they indicated were valid. All standards are subject to may be expensive. The mild steel inserts also last well revision and parties to agreements based on this without rusting, ifdue care is taken, such as cleaning standard are encouraged to investigate the possibility and greasing. Inserts of nylon or any other suitable of applying the most recent editions of the standards material may also be used. The insert shall have indicated below: conical depressions at the centre for providing line of IS No. Title contact with the conical points and a typical insert is 6524:1972 Code of practice for installation and shown in Fig. lB. observation of i nstruments for 3.1.2.1 The inserts are placed in such a position as to temperature measurement inside indicate opening and closing movements of the joint dams; resistance type thermometers and any sliding movement of the adjacent block. 10334:1982 Code ofpractice forselection, splicing, NOTE — Adequate protective covers over each installation of ,,,, installation and providing protection to inserts maybeprovided toguard against damage due tomisuse. li the open ends of cables used for 3.2 Number, Location and Layout connecting resistance type measuring The inserts should be installed on the surface atpoints devices inconcrete and masonry dams corresponding tothe locations ofjointmeters inside the 3 MEASUREMENTS OF JOINT dam. These should also befixed inside galleries across MOVEMENTS OF SURFACE BY joints, where these are accessible and at points DETACHABLE GAUGES corresponding to thejointmeter locations. 3.1 Prhciple and Construction 3.2.1 Where surface cracks are present and are considered capable of influencing the structural Measurements ofjoint movements at surface or at the integrity ofthe dam, inserts shall also be placed across locations accessible from galleries are made by such cracks for observation of crack behaviour under detachable gauges. imposed loadings. 3.1.1 Whittemore Type Gauge 3.2.2 The arrangement for fixing the inserts across the The gauge is a self-contained instrument consisting joint is shown in Fig. 1C and 1D. The arrangement essentially of two frame members bounded together shown inFig. 1C ispreferable as itgives the width of by two elastic hinges for parallel frictionless motion. opening simply by the difference in readings. 1 IS 10434 (Part 1) :2003 3.3 Method of Installation standard unstressed invar bar placed in the immediate vicinity of observation station. After the concrete is well set, holes should be drilled carefully at specified locations. The holes shall be 3.4.1 A proforma for the record of observations is cleaned of all loose material. The insert shall then be given in Annex A. placed in the holes and aligned so as to be normal to 3.5 Analysis of Data the surface of concrete in which it is being fixed. The space around the insert shall be backfilled with Analysis ofobserved data incase of the instrument not expansive mortar. Suitable gauges shall be used in compensated for temperature correction is made as aligning the axes of inserts and in getting the gauge under: length accurately. If readings at time tlare p, and i, for the concrete and 3.4 Observations invar and for time t2are p2and iz, the variation in the The inserts shall be well cleaned for taking the joint opening is given by: readings so that the instrument pins are placed in P-p’-)(i2-i’) ‘x= exactly the same position. The detachable gauge shall be placed into the inserts and the readings on the dial In the case of arrangement of inserts shown in gauge shall be observed. In order to correct the Fig. 1 D, measurements are made to determine the detachable gauges for the effect of temperature distances Al, B, and C,. varia~ions, readings of the gauge shall be taken on a ._ . 1A Schematic View ofWhittemore Type Gauge u 17 1B Whittemore and Marion Gauge Inserts 1C Position ofthe Gauge Inserts 1D Position ofthe Gauge Inserts Relative to the Joints Relative to the Joints AHdimensions inmillimetres. FIG. 1 INSTRUMENTS FORMEASUREMENTSOFJOINTMOVEMENTSATSURFACE I 2 IS 10434 (Part 1) :2003 The horizontal distance xl at time [1is obtained from 4.101.1 Construction and principle the equation: The meter is in the form of a long brass cylinder with a flange at one end and athreaded hub on the other to x,. - fit atapped socket. In practice, the socket isembedded and vertical distance in the concrete of a leading monolith to form the anchorage for the meter on one side of the contraction A;- B;+C; joint to be measured. The flange on the meter is ‘y,= 2A, engaged and held by the embedding concrete in the following monolith on the opposite side of the joint. where, at time tl Inside the brass case, a steel framework supports AI= measured distance between inserts on line ceramic pulleys and a long single loop of steel wire, parallel tojoint plane, which isheld intension bysmall coil springs. Agreater B1= distance between upper two inserts across the part of the displacement which the meter undergoes in joint, and use is taken up by the springs (see Fig. 2). The brass tube iscompletely filled with acorrosion resistant oil. Cl = distance between lower-two inserts across the Aseparate sealing chamber isprovided forterminating joint. the three rubber covered conductor cables that connect Similarly X2and y?at time tzare calculated. Between thejointmeter to the terminal boxes in the galleries. times [.land [~,the horizontal movement of thejoint is M – xl and slide movement isy2–yl. The instrument is designed to take advantage of two electrical properties of steel wire, namely, resistance 3.6 Source of Error varies directly with temperature and resistance varies Seating the gauge is one of the chief sources of error. directly with tension. When the ends of thejointmeter Application of excessive longitudinal force should be are pulled apart by opening of a joint, the outer or avoided for seating the points in the inserts. Other expansion loop elongates and increases in tension and sources of error are the dial indicator and temperature consequently in resistance as well. At the same time, changes. the inner orcontraction loop decreases inresistance as itshortens. The ratio of the resistance of the expansion 4 MEASUREMENT OF INTERNAL JOINT loop divided by the resistance of the contraction loop MOVEMENTS BY JOINTMETERS is used as a measure ofjoint opening. Temperature is %1 Jointmeters measured by taking the sum of the resistances of expansion and contraction coils. Two kinds ofjointmeters for internal joint movement measurements are in use: Since there may be considerable shearing or a) Unbended resistance type, and movement incontraction joints asadjacent blocks cool b) Vibrating wire type. at different rates, the jointmeter is designed to withstand ashearing movement of2.5 mm byreducing 4.1.1 Unbended Resistance Type Joint meter the frame section atthe ends to serve as elastic hinges. (Curl.son Type) A flexible bellows forms the central section of the ~-:--v”----“-‘- - – 260-- —- 255 . I, +..—....—- II I flTAPE SLEEvING IN pLAcE 200– ----——————Y ‘“a \,,,,,,,,,,, 57 krl~li BRAEINDDEDANFCAHBORFRILCATSLSETEEVIENLGSpRIN‘G.,- MUSIC IPIANO) WIRE COs--nI-Ln---FR{.N. P.I--A--I-EcND ANCHOR ~\~REo ‘ Rl--3.nU)-lCBVOBENEROREUDCTCOARBLE ‘L ‘WHITE TOP VIEW (INTER-COIL NOT SHOWN) BLACK All dimensionsinmillimetres. FIG.2 ELASTICWIRESTRAINMETER(CARLSONTYPE) 3 IS 10434 (Part 1) :2003 jointmeter to take the longitudinal and shear motions not more than 15 cm below the top of the lift of the case without undue straining. for easy installation. b) Screw the socket cmthe plug. Measurements of resistance ratio and resistance are c) When socket installation is complete, care made by connecting the three conductor cables to the should be taken by the workmen not to hang binding posts of astandard wheatstone bridge, circuit things on the socket or use itasastep ingetting test set in specified order in accordance with the out of the form or misuse it in any other way manufacturer’s instructions. as tocause misalignment. As aprecaution itis 4.2 Number and Location good practice to run a few stay wires to the form tokeep the socket inposition and prevent 4.2.1 Number ofjointmeters required to be provided its misalignment. The arrangement isshown in in any given dam will depend upon the dimensions, Fig. 3. block layout, provision of transverse and longitudinal d) If it is considered that for the particular con- joints or transverse joints only, configuration of the crete being used, the force exerted by the nails foundation profile, presence of specially treated in the plug and ties is greater than the bond foundation features under the dam, and the extent to resistance on the socket, to prevent pulling it which measurements of joint behaviour would prove out during form removal. The anchor should adequate in representing the joint movements for the necessarily be provided in the case of masonry entire structure. dams. 4.2.2 In the case of dams built in V-shaped canyon, e) If the cable leads are to run in the block in jointmeters should be installed inat least three blocks, which the socket is embedded, recess should namely, one central block representing deepest and be provided adjacent to the socket into which maximum section of the dam, and a block each in the not less than 1mof the cable should be coiled. abutment portions representing blocks built onsteeply 4.3.1.3 After the low block reaches the elevation in sloping abutments. Inother cases they maybe installed which the jointmeter itself is to be embedded, the one in the overflow section and one in the following procedure shall be followed: non-overflow section or any other representative block as may be decided. At a given elevation, the a) After the form is removed, remove the plug, jointmeters ineach of these blocks should be installed fill greased cloth and screw in the hexagonal at the centre of the transverse dimensions of the headed plug; monoliths in the blocks, and should be spaced about b) Complete the lift at thejointmeter location; 15 m vertically in the height of the longitudinal and c) Dig back at the location until the plug is un- transverse contraction joints as the grouting lifts covered leaving a small trench about 30 cm x (zoning ofjoints byprovision ofmetal seal) are limited 30 cm; toabout 15m inheight. This spa cing may be modified d) Back out the plug and greased cloth and insert in the top portion of the joint ifjo int height does not the jointmeter, screwing it uprigh~ permit of 15m spacing for the entire height. e) While fixing the moveable end ofjointmeter, allowance may be given for the meter, to 4.3 Method of Installation respond for expansion and contraction that is 4.3.1 Unbended Resistance Ty@eJoin[meter in both the directions. f) Tie thejointmeter cable lead out of the pour (if 4.3.1.1 Prior to the embedment of the jointmeters, cable isembedded inthe high block) and back- each instrument should be thoroughly checked for the fill with 75 mm maximum concrete, hand pud- meter resistance as also for the lead resistance and dling the concrete around the meten and these should be entered in the proforma given in g) Next day, splice the meter cable; and the cable Annex B. The resistance ratios before splicing and extension may preferably be done at the time after splicing should also be recorded in the above of embedment to allow observation to be proforma. made. 4.3.1.2 Jointmeters are supplied equipped with a 4.4 Cables and Conduits socket which should be first embedded in the high block. The socket is further provided with a slotted Guidelines regarding this aspect are provided in plug in which two holes are drilled. Procedure for the IS 10334. installation ofjointmeter atacontraction joint consists 4.4.1 Additional length of cable should be attached to of the following steps: the jointmeter by means of splicing, done either with a) Nail the plug, slotted side out, to the wooden the help of electric heat vulcanizer or by applying self form atthejointmeter location. This should be bonding tape. 4 IS 10434 (Part 1) :2003 W.-?”.-.:: K* WfOODEN RECESS Box ‘~” =CABLE WRAPPED IN x...~:~ ‘.: BURLAP ANO FRICTION Jl\l,,.-...:i.”..: b’..,.“.*,... ...b.,*.”....”.mi-”(----- & CTAOPILEEDFOIRNSI4O5EcmREACNEDSS 1 1 BOX. END SEALED. Step 1 installation in High Block J!!lHwOLE DUO AFTER COMPLETION CABLE SPLICED OF LIFT JOINTMETER SCREWED CABLE TIED UP OUT OF AFTER COMPLE- INTO SOCKET,AND BACKFILL CONCRETE LIFT HEXA- TION OF LIFT PLACED BY HANO ROUND JOlN7- GOtd HEAD PLUG HHI METER BEFORE INITIAL SET. n f . [it f h.1 a Step 2 Preparation inLow Block Step 3 Jointmeter installation FIG.3 JOINTMETERINSTALLATION 4.4.2 Provision of 10 percent or 1.5 m whichever is identification number marked on white tape should be more, over the estimated length of cable should be placed around the cable near the reading end. allowed for possible variation from selected route. 4.4.4 Provision contained in 4.3 of IS 6524 shall also 4.4.3 Each meter should be identified by a letter apply to thejointmeter installations. prefix. The normal prefix used forjointmeter isJM-1, JM-2, etc. After splicing, a copper band with the 4.5 Terminal Boards instrument identification number stamped or punched Cables shall be terminated in suitable terminal boards. on it is crimped to the cable about 1m from the free Jointmeter numbers shall be indicated in the terminal end. In addition a few more marks consisting of the boards also asdescribed in4.4.3. Ifthe terminal boards 5