IS 10434-1: Installation, Maintenance and Observation of Deformation Measuring Devices in Concrete and Masonry Dams - Guidelines, Part 1: Resistance Type Jointmeters

17 Pages·2003·1.5 MB·English

by  Bureau of Indian Standards

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