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इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

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“Step Out From the Old to the New”

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“The Right to Information, The Right to Live”

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“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 15180 (2002): Guidelines for Use in Prediction ofSubsidence and Associated Parameters in Coal Mines HavingNearly Horizontal Single Seam Workings [CED 48: RockMechanics]

IS 15180:2002

W’wfhm

FTm-ema-fawq-vi-wmm?n+rml

Indian Standard

GUIDELINES FOR USE IN PREDICTION OFSUBSIDENCE AND ASSOCIATED PARAMETERS

IN COAL MINES HAVING NEARLY HORIZONTALSINGLE SEAM WORKINGS

ICS 73.020, 73.040

(3 BIS 2002

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

. .

September 2002 Price Group 6

(Reaffirmed - 2012)

Rock Mechanics Sectional Committee, CED 48

FORE WORD

This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the RockMechanics Sectional Committee had been approved by the Civil Engineering Division Council.

Subsidence is a very comman hazard in tunneling works. This standard provides necessary information forpredicting the subsidence in single seam coal mines.

The composition of Committee responsible for the formulation of this standard is given at Annex A.

For the purpose of deciding whether a particular requirement of this standard is complied with the final value,observed or calculated expressing the result of a test or analysis, shall be rounded off in accordance with1S2:1960 ‘Rules for rounding off numerical values (revised)’. The number of significant places retained in therounded off value should be the same as that of the specified value in this standard.

f

!4

/

l“:

*-

IS 15180:2002

Indian Standard

GUIDELINES FOR USE IN PREDICTION OFSUBSIDENCE AND ASSOCIATED PARAMETERS

IN COAL MINES HAVING NEARLY HORIZONTALSINGLE SEAM WORKINGS

1 SCOPE

1.1 This standard applies to the approximate predictionof subsidence in coal mines. Prediction of horizontaland vertical displacements, slope and horizontalstrains for horizontal or nearly horizontal seams aredealt with in this standard.

1.2 The provisions of this standard are applicable to asingle seam mine at a time.

2 TERMINOLOGY

2.0 For the purpose of this standard the followingdefinitions shall apply.

2.1 Apparent Angle of Dip (CZ)— The apparent angleof dip of the seam with respect to horizontal plane.

2.2 Angle of Draw (Q — The angle between thevertical line and the line connecting the upper edge ofthe working to the edge of the subsidence trough(see Fig. 1).

SUBCRITICAL WIDTH

\

\

t

L-CRITICAL wIDTH—+ ~

1- SUPER CRITICAL WIDTH

FIG. 1 SUCCESSIVEDEVELOPMENTOF SUBSIDENCEPROFILE

1.

IS 15180:2002

2.3 Subsidence (S) — The vertical movement of anypoint on the surface caused by an undergroundexcavation (see Fig. 1).

2.4 Maximum Subsidence (S.) — The maximumvertical displacement caused by an undergroundexcavation on the surface in a subsidence affected area(see Fig. 1).

2.5 Maximum Possible Subsidence (S~J — Themaximum vertical movement that can be caused onthe surface in a given locality by an undergroundexcavation of such a critical dimension (see Fig. 1).

2.6 Panel –-A part of the mine workings from wherethe mineral or coal has been or is being mined out.

2.7 Pillar — A block of coal left unexcavated to offersupport to the roof of the workings.

2.8 Critical Length or Width — The length or widthof excavation or working panel that causes maximumpossible subsidence (S&J at a single point on thesurface (see Fig. 1).

2.9 Super-Critical Length or Width — The lengthor width of the panel larger than critical dimension(see Fig. 1).

2.10 Sub-Critical Length or Width — The lengthor width of the panel smaller than critical dimension(see Fig. 1).

2.11 Curvature (1/P ) — The reciprocal of the radiusof curvature of any part of the subsided surface profile.

2.12 Depth (d) of Overburden — The verticaldistance from the roof of the extracted seam to a pointvertically above it on the surface.

2.13 Slope (g) — The slope of any part of thesubsidence profile or subsidence trough.

2.14 Strain (e+) — Change per unit length in thedistance between any two points on the surface in aspecified direction. The tensile strains are consideredas positive (e.+)and the compressive strains as negative

(e_).

2.15 Critical Area (AC,it) — The minimum area ofexcavation that causes maximum possible subsidenceof one point cm the surface (see Fig. 1).

2.16 Sub-Critical Area (AJ — An excavation areasmaller than the critical area. The subsidence causedby this area is smaller than maximum possiblesubsidence (S~J at any point (see Fig. 1).

2.17 Super-Critical Area (A,UP) — An area ofexcavation larger than the critical area. The subsidencecaused by this area of excavation is equal to the

maximum possible subsidence (S~J at floor of thesubsidence trough (see Fig. 1).

3 PREDICTION OF MAXIMUM POSSIBLESUBSIDENCE (S~J

3.1 Data Required for the Prediction of ~~a,

The following data is required for calculating theanticipated magnitude of S~OXfor a given mining andgeological situation:

a)

b)

c)

d)

e)

o

Extracted thickness of the seam (m);

Extraction ratio (ER) that is the ratio ofextracted volume of coal or mineral to its totalvolume in the given panel;

Method of goaf support that is caving,stowing, etc;

Depth of workings (d) below the surface level;

Angle of dip (a) of the seam; and

The Young’s modulus Ev (in the directionperpendicular to the bedding plane) and theshear modulus G, of the rockmass. In theabsence of homogeneity; the overall(weighted average) vaiues of Ev and G shouldbe used for the following situations:

1) Presence of hard rock layers, namely,sandstone, limestone, etc, in theoverburden rockmass;

2) Presence of old or current workings inthe vicinity of the panel and the partingbetween them; and

3) Presence of geological discontinuities,namely, joints, fractures, etc.

3.2 Prediction of S~oX

The maximum possible subsidence in a given areadue to critical or super-critical excavation is givenby:

s ~ax = mef gf Rf dfd’t ....... (1)

where

m=

ef =

gf =Rf =

d, =#=

t=

2

Extracted seam thickness,

Extraction factor,

Goaf treatment factor,

Rock factor for the combined effect ofcomposition and condition of theoverburden rockmass,

Factor for the effect of depth of working,

Factor for the effect of dip of the seam,and

Time factor (taken to be unity for finishedsubsidence).

%.’

3.2.1 Extraction Factor (e~)

The effect of partial extraction on S~oXis given by theextraction factor equal to (ER)K where ER is theextraction ratio (ratio of extracted volume to the totalvolume of the coal within the panel, in fkaction) andK is a constant. The value of K may be taken equal toI for general cases of soft coal seam and 2 for hardcoal seams and may be interpolated between 1 and 2for intermediate cases. Alternatively, the value ofextraction factor should be taken from Fig. 2. Coalhaving uniaxial compressive strength of 15 MPa(150 kg/cm2) or more should be considered as of ‘hard’quality and less than that of ‘soft’,

3.2.2 Goaf Treatment Factor (@

The value of this factor should be taken as 0.95 forcaving cases and 0.07 to 0.10 for cases of hydraulicsand-stowing as goaf support.

3.2.3 Depth Factor (dJ

The factor for the depth of coal seam should be takenequal to 0,87 for depths up to 250 m; 0.96 for depthsbetween 250 and 400 m and 1.0for depths beyond 400 m.

3.2.4 Factor for the Apparent Dip of the Seam (d’)

This factor should be taken as equal to cosct, where ciis the angle of apparent dip in degrees (for its valuesup to 20”).

3.2.5 Rock Factor (RJ

The effect of composition and condition of overburdenrockmass on S~mshould be quantified by a factor called

Is 15180:2002

rock factor R~ whose value lies between O for nosubsidence to 1.0 for the maximum value of S~aX.Thepresence of hard rock layers in the overburdenrockmass results in the reduction of subsidence,whereas its fragmentation makes it weaker, thusincreasing the subsidence.

On the basis of its condition, the overburden rockmassis classified from subsidence point of view into fivecategories as given in Table 1. In Table 1, E, is the

Young’s modulus of overburden rockmass in adirection perpendicular to the bedding plane and G isshear modulus. The ratio G/Ev represents the strengthof rockmass in which Ev may be empirically corelatedto the presence of hard rock layers in the overburdenby the following formula:

E, (in MPa) = 500 + (195 x percentage of hardrock layers in the overburden)

The condition of the overburden rockmass that is thepresence of natural discontinuities and the degree offragmentation caused in it because of repeated workingmay be expressed in terms of G/Ev ratio. The range ofG/Ev ratio for each classification of rockmass is alsogiven. The rock classification for a given overburdenrockmass should be found out either from its G/Evratio or from the description given in Table 1.

The rock factor R~should be obtained for a given

rockmass (as classified in Table 1), either by knowingits Young’s modulus Ev and shear modulus G, or byknowing the percentage of hard rock layers in theoverburden from the respective curve given in Fig. 3.

t

(ER)

1.0 -

08 -

06 - /

K/

/0

O*L -

00

0— SOFT COAL

00 --- HARD COAL

0.2 - ~~.

11 I i 1 t # I

0“4 0“5 0“6 o ‘7 0“8 0.9 1.0

ER (EXTRACTION RATIO )-

FIG. 2 EFFECTOFPARTIALEXTRACTIONONSUBSIDENCE

3

IS 15180: 2002

1.0

049 -

:Lo.ol----! 0.6

a-.05

a01- 1v4 0.4 Iu. I

0.3 -

:1 :

0.0 10 20 30 ho 50 60 TO 80 90 10

PERCENTAGE OF HARD ROCK LAYERS~IN THE OVERBURDEN

FIG. 3 RELATIONSHIPBETWEENR~ANDHARD ROCKLAYERSINTHEOVERBURDEN

Table 1 Classification of Overburden Rockmass

(Clause 3.2.5)

SI ClassificationNo.(1) (2)0 Competent

rockmassii) Undisturbed

rockmassiii) Partially

disturbedrockmass

iv) Disturbedrockmass

v) Highly disturbedrockmass

G/E,

(3)0.07-0.38

0.03-0.07

0.016-0.03

0.oo5-0.016

<0.005

Description

(4)Massiverockmasswithfewplanesof weaknessesNo previousminingbut fewnatural dkxontinuitiesParting between the minedseams more than 5 times theseam thickness; or caseswith no previous mining butmany natural dk.continuitiesParting between the minedseams not more than 5times the seam thickness; orhaving over lyinghrnderlying or side lying workingsin the vicinity of the panel.Highly fragmentedrockmass with repetitiveworkhrgs or having verythick seams mined indescending slicing

.,

4 PREDICTION OF MAXIMUM SUBSIDENCEFOR ASUB-CRITICAL AREA OF EXTRACTION

4.0 The maximum possible subsidence S~moccurs ator near the certtre of the panel when its length (/) andwidth (W), each is more than or equal to criticaldimension.

4.1 If the length of the panel is critical or super-criticaland width is sub-critical, the maximum subsidence SOnear the centre of the panel will be less than S~aXandis given by:

s= sMaxw’ ....... (2)

whereW’= [ 1- exp{–n(W/d)2}] ....... (3)

4.2 If besides the width, the length of thepanel is also of sub-critical dimension, the maximumsubsidence SOwill be given by:

SO= SMmW’L’ .. ..... (4)

whereL’= [ 1- exp{ -n(//d)2}] ....... (5)

4

i,:,,,

where n is an empirical constant value of which liesbetween 2.5 and 3.5 (average 3.0)

5 SUBSIDENCE PROFILE FOR ARECTANGULAR PANEL

The subsidence at any point along the central line ina rectangular panel and along the other lines parallelor perpendicular to the central line can be predictedby knowing:

a)

b)

c)

d)

e)

the maximum subsidence due to theexcavated panel,

the maximum subsidence along the givenline,

distance of the line from the point undergoingmaximum subsidence in whole of the panel,

the distance of the given point from the pointundergoing maximum subsidence along thatline, and

the angle of draw on both ‘sides of thesubsidence profile.

5.1 Angle of Draw (~

Figure 4 gives the magnitude of angle of draw 41 indegrees on the commencing side (or static end) fordifferent W/d ratios and for a given rockmassrepresented by rock factor RF The angle of draw 62on

IS 15180:2002

the other end (dynamic end or moving face side)should be found out from Fig. 5.

5.2 Subsidence Trough Due to Nearly HorizontalRectangular Excavation

The subsidence trough in a horizontal or nearlyhorizontal excavation goes upto a distance r, equal tod tan & on the commencing side and up to a distancerz equal to d tan <2beyond the limit of excavation onthe dynamic face side as shown in Fig. 6.

The point undergoing maximum subsidence SOor Sht,,rlies in the centre of a sub-critical and critical panelrespectively. In case of super-ciritical panel, an areaon the surface above the central portion of the panelundergoes the maximum possible subsidence.Therefore in such cases a subsidence trough with alevel floor at full subsidence S~a is produced. Thepoints undergoing full subsidence along a longitudinalor transverse central line profile are situated betweentwo points X‘ and X” (see Fig. 6) lying at a distance ‘r, equal’ to d tan <1 and at a distance r2 equal to

dtan <2respectively from the stationary rib and movingtowards the centre of the panel. Alternately these twopoints~ ‘andX” are situated at a distance of (W/2 - r,)and (W/2 – r2) ffom centre of the panel towards thecommencing and finishing sides respectively (see Fig.6), where w is the width of the panel.

Rf (091- 1.00)---- —-——- -— –-–—45°

/./

/*

// Rf(O~66- 0.90)/ .I. 35°

/

/

/ ++

// + o 0/ Rf(o.36-0*65)

/ ++

/

25°0

0 %0o

/A Rf(< o.36)

16”

f

+ AA

01 I 1 1 I t 11 2 3 4 5 6

W/d RATlO

FIG. 4 ANGLEOFDRAW ONCOMMENCINGSIDE(~) FORDIFFERENTW/d RATIOSANDR~VALUES

5

IS 15180:2002

●

Rf (091- +00) _ _ _350.- -.—— —--- --—-

/ ●

/ +/

/ Rf (046 -0.9)/

28°

A-’’”// +/++:0 0 Rf(O.36-O.65)

++ ~ 20°

(+

//.

0’=%0 00 Rf(O-O.35)

10°

A

/A

I I , 1 , t

o 1 2 3 4 5 6W/d RATIO

FIG. 5 ANGLEOFDRAW ONFINISHINGSIDE(&2) FORDIFFERENTW/d RATIOSANDR~VALUES

—r.

.. ..

I

4 *r -4FIG. 6 SUBSIDENCETROUGHDUETOSUPER-CRITICALEXCAVATION

5.3 Subsidence Profile for Rectangular Excavationin Nearly Horizontal Seams

The vertical displacements SXthat is subsidence at apoint at a distance x from the centre of a sub-criticalpanel may be found as shown in Fig. 8:

SX=SO[exp { –M(.Y/(r +X)2 }] . ..(6)

and, for critical and super-critical extractions;

SX= S~ax[ exp { – M(x/(r + X)2}] . ..(7)

where

x = distance of the given point from the centreof a critical or sub-critical panel, or

= distance of the given point from the nearestpoint undergoing S~a along that profile

6.,

r=

J/f.

line (see Fig. 6) inpanel.

Critical diameter =

case of super-critical

(r]+ r,)Profile constant on which the shape of thesubsidence profile depends. Vaiue of Mmay be found out from Fig. 7 dependingon the value of R~. The higher value of Rr(that is, for more disturbed rockmass) themore is the value of Mand the sides of thesubsidence trough will be steeper.

5.4 Subsidence Trough for Panels with IrregularBoundaries

An example of extraction area with irregular boundaryis shown in Fig. 8. The value of S~aXor SOshould befound out from equations (1) and (4) by averaging the

IS 15180:2002

2 “o I 1 I 1 i I I 1 I I I 10 0 “2 0“4 O “6 0“8 1.0 1.2

Rf

FIG. 7 RELATIONSHIPBETWEENR~ANDM

1I II II

r ..—1

I

I fI 4II+* 4I 1 I (1

I III

IIII

0 !ji SUBSIDENCE AT THE CENTRES OF IMAGINARY PROFILES

● Sj SUBSIDENCE AT THE CENTRES OF ACTUAL pROFll ES

---- IMAGINARY PROFILES CONSIDERING RECTANGULAR BOUNOARY

— ACTUAL PROFILES CONSIDERING ACTUAL BOUNDARY

FIG. 8 IMAGINARYANDACTUALPROFILELINESINEXCAVATIONSWITHIRREGULARBOUNDARY

boundaries of the excavation and simulating it to beof rectangular shape. Two main profile lines onelongitudinal and the other at right angles to this andboth passing through the centre of the panel shouldbe drawn.

The extraction area should be treated as rectangularin shape, considering the longest dimension as itslength and the longest dimension perpendicular to thisas its width. The value of subsidence Si for all pointsat a suitable distance interval & along these two mainprofiles are calculated by profile function that is fi-omequations (6) and (7). Imaginary profile lines, paralleland equal in length to the main transverse profile aredrawn (at a distance dx apart) and undergoing

subsidence Siat their centres are calculated. The valuesof subsidence Sj at all the points at a distance a!xapartalong these imaginary profiles (with respect to theassumed rectangular extraction) are calculated withequations (6) and (7) given in 5.3 by replacing Si forSOor S~oX.The subsidence values ~ thus obtained aredue to assumed rectangular excavation.

Now considering each transverse profile of its actuallength (or width) intercepted between actualexcavation boundary, their centres are found out atwhich subsidence value Sj is known already. Themagnitude of angle of draw for each actual width (orlength) ratio is found out from Fig. 4 and Fig. 5 forcalculating the extent of each profile. The subsidence

, -----

7.

IS 15180:2002

—ACTUAL BOUNDARY; - --— IMAGINARY BOUNDARY

FIG. 9 SUBSIDENCEPROFILESBYINTERPOLATION

at all points at a distance & apart along these actualprofiles (see Fig. 9) is now estimated from equations(6) and (7) by substituting Sj for S~aX.

6 PREDICTION OF OTHER ASSOCIATEDPARAMETERS

6.1 The parameters associated with subsidencemovements, which may have damaging impacts onvarious surface properties and structures are, the slopeof the subsidence profile curve, horizontaldisplacements of the surface points, horizontal strainsthe ground points experience and the curvature of theground.

6.2 Determination of Slope or Tilt

Slope or tilt gives the variation of differentialsettlement between two points on the ground. Theslope gi, of a subsidence profile at the ith point at adistance x from the centre of the panel is the derivativeof subsidence with respect to the distance. The slopebetween two consecutive points say ith and (i – l)thfrom the panel centre can geometrically be obtainedas:

gi=AJAX= (Si– Si_,)/Ax .......(8)where

Siand Si-l are the vertical settlements (or subsidence)of the ith and (i – 1)th points and AXis the distancebetween these two points. Therefore the slope is thedifferential subsidence between two consecutive pointson subsidence profile situated at 1 m apart and isexpressed in mm/m.

6.3 Determination of Horizontal Displacement

The surface points in a subsidence trough are subjected

to vertical as well as horizontal displacements. Theprofile curve of horizontal displacements is similar innature to the profile curve of slopes. A linearproportionality exists between the two curves. Thehorizontal displacement Uiat ith point from the panelcentre is given by

where

g, =

B=

Ui = Bg.I ......(9)

slope at the ith point,

Proportionality constant which isdependent on the nature of the overburdenrockmass that is the rock factor RP and onthe W/d ratio of the extracted panel (seeFig. 10).

6.4 Determination of Horizontal Strains

The horizontal strains (ei,j are given by:

Au,eii -

AX ...... (lo)

where

u. = Difference in horizontal displacements ofthe two consecutive points that is ith and(i- l)th which were originally situated ata distance AXapart. Aui is found out asfollows:

Aui = Ui– Ui_, ......(11)

The horizontal strains as obtained from equation ( 10)are positive (e+) or tensile for points situated in theouter areas of the subsidence trough and are negativeor compressive (e] for points situated towards thepanel centre.

8

60 -

50 -

m.

5 40 .$mzov

53 0

20i=

~2 o-0aa

10-

1S 15180:2002

II oI I , I 1 , I I

o 0.4 0“8 1.2 1,6 2.0 2“4

wld

FIG. 10 VALUESOFB FORDIFFERENTW/d Ihmo

6.5 Determination of Surface Curvature

The curvature of the ground (Ki) is the first derivativeof the slope. It is the change in the slope per unitlength.

The curvature is given by:

......(12)

where

gi = difference in slope at ith and (i – l)thpoint.

7 NON-EFFECTIVE WIDTH

The maximum width of an underground opening that

does not produce any significant movement on theground surface is called the non-effective width(NEW). The concept of NEW is helpful in the designof the underground excavations and in controlling orminimizing the subsidence movements by keepingthem within tolerable limits. The value of NEW isnormally expressed as the ratio of this width to thedepth of the excavation. The value of NEW dependson the nature of overburden rockmass, the thicknessof the coal seam and the extraction ratio. The valuesof NEW for longwall workings (100 percentextraction) and for 50 percent extraction in board andpillar workings are given in Fig. 11 and Fig. 12 forindifferent seam thicknesses.

9

,

IS 15180:2002

1-0

0.8

3uz

0.

NEW— NON EFFECTIVE WIDTHNEW FOR 50% EXTRACTION IN BOARDAND PILLAR WORKINGS

m=lm

m.2m

m=3mm=5m

I I 1 I 1 i I 1 1

0.2 o.L O ‘6 04 1.0

Rf

FIG. 11 VALUESOFNEW FOR50 PERCENTEXTRACTION

.

NON EFFECTIVE WIDTH [NEw)

FOR LONGWALL WORKINGS

[100% EXTRACTION)

m . THICKNESS OF SEAM.

m=lm

1

m=zmm=3mm=~m

I 1 I 1 1 I

) 0“2 0“4 0.6 0’8 1“oRf

,

FIG. 12 VALUEOFNEW FORLONGWALLWORXINGS

10

IS 15180:2002

ANNEX A

(Foreword

COMMITTEE COMPOSITION

Rock Mechanics Sectional Committee, CED 48

Organization

[n personal capacity (1 66/2, Vikas Nagar University of Roorkee,Roorkee-247667)

AFCONS Infrastructure Ltd, Mumbai

AIMIL Ltd, New Delhi

Central Board of Irrigation& Power, New Delhi

Central Building Research Institute, Roorkee

Central Ground Water Board, New Delhi

Central Mining Research Institute, Dhanbad

Central Road Research Institute, New Delhi

Central Soil & Material Research Station, New Delhi

Central Water & Power Research Station, Pune

Engineer-in-Chiefs Branch, New Delhi

Geological Survey of India, Lucknow

Gujarat Engineering Research Institute, Vadodara

Himachal Pradesh State Electricity Board, Shimla

IndianGeotechnical Society,New Delhi

IndianInstituteofTechnology, New Delhi

IrrigationDepartment, Government of Mahamsht~ Nasik

Irrigation ~epartment, Government of Haryana

Irrigation Department, Government of Gujarat, Gandhinagar

Irrigatio!tResearch Institute, Roorkee

Irrigation andPowerDepartment,ChandigarhKamatakaEngineeringResearch Station, Krkhnarajasagar (Kamataka)

Naptha Jakri Power Corporation, Wimla

National Geophysical Resewch Institute, Hyderabad

National Thermal Power Corporation Ltd, Noida

Universityof Roorkee, Roorkee

Representative(s)

DR BHAWAM SrNGH(Chhnon)

SHRSA.D.LONOHESHRSV.S. KUrMRM(Alterrrute)

Smu M. D. NMRSmu B. K. SASGAL(Alternate)

DIRECTOR(WR)GENERALMANAGER (Alternatz)

SHNPRABHATKOMAR

Ssau V.~SHNA (Alternate)

SHSUo. P. PAL

DR R. K. GOELSEUUJ. R. MOHNOT(Alrerrrate)

%U 0. p. YADAV

DR KISHORKUMAR(Alternate)

JorNTDLRECTOR

DR R. B. SrNGH(Alternate)

DIRKTOR

Mu B. K. RAMSGOWDA (Alternate)

SHRSD. K. JAINSmuV. S. ARoru+(Allernate)

SW B.DEBNAIHDR U.P. GGPTA(Alternate)

DRV.S.Brwmmarwrr@EARCH Gmcm (Alternate)

DRR.L. CHAUHAN

DRK. S. RAO

SrmrK.K. GIJPTA

DRR.P. KULRARNS

C= ENOUWES(R& D)~R (ENGINEERMG)(Alternate)

SsmrD. M. PANCHOU

ASSISTANTksEARCH~CER

SsarrK.m04vm

SmuB.G.MUDHOLSHRIJAGANNATHARAO(Alternate)

SHRSRANJODHsrNGH

SHRSA. K. CHADDHA(Alternate)

scENnsPrN-CH.mGE

DR D.N. NARESHSmrrR.R.MAURYA(Alternate)

PROPP. K. J.MN

DR M. N. VILADKAR(Alternate)

(Continuedonpage 12)

11

Is 15180:2002

(Corr[irruecifrmrpage11 )

Organization

In personal capacity (A TES, AIMIL Ltd, Delhi-Mathura Road,New De[hi -110 044)

BIS Directorate General

Representative(s)

DR V.M. SHARMA

Srou S. K. JAIN,Director & Head (Civ Engg)~epresenting Director General (Ex-oficio)]

Member Secreta~

SirruD.K.kRAWALJoint Dhector (Civ Engg) BIS

Underground Opening and Field Monitoring Subcommittee, CDE 48:3

Universityof Roorkee, Roorkee

AIMIL Ltd, New Delhi

AdvancedTechnology&Engineering Services,New Delhl

Central Building Research Institute, Roorkee

Central Mining Research Institute, Roorkee

Central Mining Research Planning and Design Institute,Ranchi

Central Soil & Material Research Station,New Delhi

Central Water Commission, New Delhi

Geological Survey of Indi~ Kolkata

Gujarat EngineeringResearch Institute,Vadodara

Indian Instituteof Technology, Mumbai

Indian Instituteof Technology,New Delhi

Indian InstituteofTechnology, Kanpur

Jaiprakash Associates Pvt Ltd, New Delhi

Konkan Railway, Navi Mumbai

Kvamer Cementation India Ltd, Kolkata

M. S. Univerity,Vadodara

Maharashtra Research and Physics Division, Nasik

National Institute ofRock Mechanics, Kolar

Universityof Roorkee, Roorkee

VisvesvarayaRegional College of Engineering,Nagpur

DR SURHASHMrrRA (Convener)

Stnu M. D. NAIRStmrB. K. SAIGAL(Altermte)

SHRIB. DASGUPTA

%0 A. GHGSHSHRIY. PAmEY (Alternate)

DR R. K.GOEL

DR k SWARGGP (Alternate)

,%U S. &WRALIORIYDR M. M. SOM (Alternate)

DRA. K.~WANSHSUR.msvKumrt(AJternate)

-OR (SSPH)DIRECFOR(Drv II) (Alternate)

SHIUA.BH.MTACHARAYAS-auS.K.MUKHOPADHVAY (Aknate)

Smu U.D. DATTR

DRG. VENKMWCHALAM

DR K. G. SHMMA

DRsARvEsHcH4NGR4

Smu D. G. KADRAGE

SHWR. K. JMN (Alternate)

SHIUNARAYANAN

Smu S. B. SENSrmrP. S. Sarwr.rmA(AL@rrate)

DR A. V. SHRGFP

Rt3E4RcHGFFrcm

SmuN. M. RAJU

Smu B. SmuNo,wmrrr (Alternate)

DRM.N. VrLADKAR

DRA.G. Pmmrmwwt

12

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8 & ‘,’

Bureau of Indian Standards

BISisastatutoV institution established under the BureuuoJZndian Standards Act, 1986 topromote harmoniousdevelopment of theactivities of standardization, marking andquali~certification ofgoods and attending toconnected matters in the countq’.

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Review of Indian Standards

Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewedperiodically; a standard along with amendments is reatTmmedwhen such review indicates that no changes areneeded; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standardsshould ascertain that they are in possession of the kitest amendments or edition by referring to the latest issue of‘BIS Catalogue’ and <Standards: Monthly Additions’.

This Indian Standard has been developed from Dot: No. CED 48 (5605).

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

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