Disclosure to Promote the Right To Information

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इंटरनेट मानक

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

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 13365-1 (1998): Quantitative classification system ofrock mass - Guidelines, Part 1: RMR for predicting ofengineering properties [CED 48: Rock Mechanics]

IS 13365 ( Part 1 ) : 1998 Reaffirmed 2010

~~~~~-~ff~

'q11J 1~~c6~c6~~mnt~ (am'tRam)

Indian Standard

QUANTITATIVE CLASSIFICATIONSYSTEMS OF ROCK MASS — GUIDELINES

PART 1 ROCK MASS RATING (RMR) FOR PREDICTINGENGINEERING PROPERTIES

ICS 93.020

© BIS 1998

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

July 1998 Price Group 6

AMENDMENT NO.1 OCTOBER 2008TO

IS 13365 (pART 1): 1998 QUANTITATIVECLASSIFICATION SYSTEMS OF ROCK

MASS - GUIDELINES

PART 1 ROCK MASS RATING (RIIR) FOR PREDICTINGENGINEERING PROPERTIES

(Page 4, Fig. 1) - Substitute the following for the existing figure:

to'101.00.1

20+----t-----+---+------........-r;---~...----+...-.--I

15

e 10+-----+---------t--~~------...~

I e +-----.+------....e-+r---___+_-

I 2~+--~~+---+-------I

STAND-UP nME. hr

FlO. 1 STAND-UP TIME VIS UNSUPPORTED SPAN AS PER RocK. MAss RATING

(CED48)

RepJ'Oll'lPhy Unit, BIS,New Delhi. Indi.

Rock Mechanics Sectional Committee, CED 48

FOREWORD

This Indian Standard (Part I) was adopted by the Bureau of Indian Standards, after the draft finalized by theRock Mechanics Sectional Committee had been approved by the Civil Engineering Division Council.

Quantitative classification of rock masses has many advantages. It provides a basis for understandingcharacteristics ofdifferent groups. It also provides a common basis for communication besides yieldingquantitative data for designs for feasibility studies ofproject. This is the reason why quantitative classificationshave become very popular all over the world.

Rigorous approaches of designs based on various parameters could lead to uncenain results because ofuncertainities in obtaining the correct value of input parameters at a given site of tunnelling. Rock massclassifications which do not involve uncertain parameters are following the philosophy of reducinguncertainities. Part 2 of this standard presents Quantitative Classification System, and Part 3 offers details ofSlope Mass Rating.

Technical Committee responsible for the formulation of this standard is given in Annex D.

In reporting the result of a test or analysis made in accordance with this standard, if the final value, observed orcalculated, is to be rounded off, it shall be done in accordance with IS 2 : 1960 'Rules for rounding off numericalvalues (revised)'. The number of significant places retained in the rounded off value should be the same as thatof the specified value in this standard.

IS 13365 ( Part 1 ) : 1998

Indian Standard

QUANTITATIVE CLASSIFICATIONSYSTEMS OF ROCK MASS - GUIDELINES

PART 1 ROCK MASS RATING (RIA", FOR PREDICnNGENGINEERING PROPERTIES

1 SCOPE

This standard (Part 1) covers the procedure fordetermining the class of rock mass based ongeomechanics classification system which is alsocalled the Rock Mass Rating (RMR) system. Theclassification can be used for estimating theunsupported span, the stand-up time or bridge actionperiod and the support pressures of an undergroundopening, It can also be used for selecting a method ofexcavation and permanent support system. Further,cohesion, angle of internal friction and elasticmodulus of the rock mass can be estimated. In itsmodified fonn RMRcan also beused for predicting theground conditions for tunnelling.

It is emphasized that recommended correlationsshould be used for feasibility studies andpreliminarydesigns only. In-situ tests are essential for final designof important structures.

2 REFERENCES

The Indian Standards given in Annex A containprovisions which through reference in this text,constitute provision of this standard. At the time ofpublication, the editions indicated were valid. Allstandards are subject to revision. and parties toagreements based on this standard are encouraged toinvestigate the possibility of applying the most recenteditions of the standard indicated.

3 PROCEDURE04 ..

To apply the geomechanics classification system, agiven site should be divided into a number ofgeological structural units in such a way that eachtype of rock mass present in the area is covered. Thefollowing geological parameters are determined foreach structural unit:

a) Uniaxial compressive strength of intact rockmaterial (IS 8764),

b) Rock quality designation [IS 11315 (part 11)],c) Spacing of discontinuities [IS 11315 (Part 2)],d) Condition ofdiscontinuities [IS 11315 (Part 4)],e) Ground water condition [IS 11315 (Part 8)]. andt) Orientation of discontinuities [IS 1131S

(Part 1)].

3.1 Collection of Field Data

Various geological and other parameters givenin 3.1.1 to 3.1.6 should be collected and recorded indata sheet shown in Annex B.

3.1.1 Uniaxial Compressive Strength of Intact RockMaterial (qc)

The strength of the intact rock material should beobtained from rock cores in accordance withIS 9143 or IS 8764 or IS 10785 as applicable based onsite conditions. The ratings based on uniaxialcompressive strength andpoint load strength aregivenin Annex B (Item I). However the use of uniaxialcompressive strength is preferred over that of pointload index strength.

3.1.2 Rock Quality Designation (RQD)

Rock quality designation (RQD) should bedetermined as specified in IS 11315 (part 11). Thedetails of rating are given in Annex B (Item Il),

Where the rock cores are not available, RQD can bedetermined with the help of following formula:

RQD = 115-3.3Jv

= 100 for J; < 4.5

where

J, =numberof joints per metre cube.

Minimum value ofRQD is taken as 10even ifit is zero.

3.1.3 Spacing ofDiscontinuities

The term discontinuity covers joints, beddings orfoliations. shear zones, minor faults, or other surfacesof weakness. The linear distance between twoadjacent discontinuities should be measured for allsets of discontinuities. The details of ratings are givenin Annex B (Item III).

3.1.4 Condition ofDiscontinuities

This parameter includes roughness of discontinuitysurfaces, their separation, length or continuity,weathering of the wall rock or the planes of weakness.and infilli ng (gauge) material. The details of rati ng aregiven in Annex B (Item IV).The description of theterm used in the classification is given in IS 11315(Part 4) and IS 11315 (Part S).

IS 13365 ( Part 1 ) : 1998

3.1.5 Ground Water Condition

In the case of tunnels, the rate of inflow of groundwater in litre per minute per 10m length of the tunnelshould be determined.• or a general condition can bedescribed as completely dry, damp, wet, dripping,and flowing. If actual water pressure data areavailable, these should be stated and expressed interms of the ratio of the water pressure to the majorprincipal stress. The latter should beeither measuredfrom the depth below the surface (vertical stressincreases with depth at 0.27 kg/cm2 per metre of thedepth below surface). The details are given in AnnexB (Item V).

Rating of above five parameters (see 3.1.1 to 3.1.5)is added to obtain what is called the basic rock massrating (RMRbasic).

3.1.6 Orientation ofDiscontinuities

Orientation of discontinuities means the strike anddip of discontinuities. The strike should be recordedwith reference to magnetic north. The dip angle isthe angle between the horizontal and thediscontinuity plane taken in a direction in which theplane dips. The value of the dip and the strike shouldbe recorded as shown in Annex B (Item VI) for eachjoint set ofparticular importance that are unfavourableto the structure. In addition the orientation of tunnelaxis or slope face or foundation alignment should alsobe recorded.

The influence of the strike and the dip of thediscontinuities is considered with respect to theorientation of tunnel axis or slope face or foundationalignment. To facilitate the decision whether the strikeand dip are favourable or not, reference should bemade to Annex C, Tables Cl and C2 which giveassessment of joint favourability for tunnels and damsfoundations respectively. Once favourability ofcritical discontinuity is known, adjustment fororientation ofdiscontinuities is applied as per Item VII,Annex B in earlier obtained basic rock mass rating toobtain RMR.

4 ESTIMATION OF ROCK MASS RATING(RMR)

4.1 The rock mass rating should be determined asan algebraic sum of ratings for all the parametersgiven in Items I to VI after adjustments for orientationof discontinuities given in item vn of Annex B. Thesum of Items II to V is called Rock Condition Rating(RCR) which discounts the effect of compressivestrength of intact rock material and orientation ofjoints. This is also called as the modified RMR.

4.2 On the basis of RMR values for a givenengineering structure, the rock mass should beclassified as very good (rating 100-81). good (80-61),fair (60-41), poor (40-21) and very poor «20) rockmass.

4.3 RCR may also be obtained from Q.SRF value asfollows:

RCR =8 In (Q.SRF)+30

Q.SRF has been named as rock mass number anddenoted by N. By doing so, the uncertainities inobtaining correct rating of SRF is eliminated asexplained below:

Q = (RQDIJn)(JrlJa)(JwISRF)

or N =Q.SRF = (RQDIJn)(JrlJa)Jw

It can be seen in above equation that N is free fromSRF. RQD, In, Jr. la, and Jw are parameters as definedin IS 13365 (Part 2).

4.4 In the case of larger tunnels and caverns,RMR may be somewhat less than obtained fromdrifts. In drifts, one may miss intrusions ofother rocksand joint sets.

4.5 Separate RMR shall be obtained for differentorientation of tunnels after taking into account theorientation of tunnel axis with respect to the criticaljoint set (Item VI, Annex B).

4.6 Wherever possible, the undamaged face should beused to estimate the value of RMR, since the overallaim is to determine the properties of the undisturbedrock mass. Severe blast damage may be accounted forby increasing RMR and RMRbasic by 10.

S ENGINEERING PROPERTIES. OF ROCKMASSES

5.1 The engineering properties of rock masses canbeobtained from this classification as given inTable 1 based on assumptions given in 5.1.1 to 5.1.3.If the rock mass rating lies within a given range,the value of engineering properties may beinterpreted between the recommended range ofproperties.

5.1.1 Average Stand-up Time

The stand-up time depends upon effective span of theopening which is defined as size of the opening orthe distance between tunnel face and the adjoiningtunnel support, whichever is minimum (see Fig. 1).For arched openings the stand-up time would besignificantly higher than that for flat roof openings.Controlled blasting will further increase the stand-uptime as damage to the rock mass is decreased.

5.1.1 Cohesion and Angle ofInternal Friction

Assuming that a rock mass behaves as a Coulombmaterial, its shear strength will depend upon cohesionand angle of internal friction. Usually the strengthparameters are different for peak failure and residualfailure conditions.

The values of cohesion for dry rock masses of slopesare likely to be signficantly more.

2

For underground openings, the values ofcohesion willstill be higher (see 5.1.5 and 5.1.6).

5.1.3 Modulus ofDeformation

There are three correlations for determiningdeformation modulus of rock mass.

5.1.3.1 Figure 2 gives correlations between rock massrating (RMR) and modulus reduction factor (MRF) ,which defined as ratio of modulus of elasticity (see IS9221) of rock core to elastic modulus of rock mass.Thus, modulus of deformation of rock mass bedetermined as product of modulus of elasticity of rockmaterial (Er) and modulus reduction factorcorresponding to rock mass rating from the equationbelow (for hard jointed rock).

Ed = Er.MRF

The correlation for MRF is shown in Fig. 2.

5.1.3.2 There is an approximate correlation betweenmodulus of deformation and rock mass rating forhard rock masses (qc;; ~ 50 MPa).

Ed = 2 x RMR-lOO, in GPaorEd = 10(RMR-:-IO)/40, in GPa (for all values of

RMR)

These correlations are shown in Fig. 3.

For dry soft rock masses (qc < 50 MPa) modulus ofdeformation is dependent upon confining pressuredue to overburden.

Ed = O.3zQ I O(RMR- 20)/38, in GPa

(X = 0.16 to 0.30 (higher for poor rocks)

z = depth of location under considerationbelow ground surface in metres (fordepths ~ 50 m).

The modulus of deformation of poor rock masseswith water sensitive minerals decreases significantlyafter saturation and with passage of time afterexcavation. For design of dam foundations, it isrecommended that uniaxial jacking tests with borehole extensometers, wherever feasible, should beconducted very carefully soon after the excavation ofdrifts particularly for poor rock masses in saturatedcondition,

I

5.1.4 Allowable Bearing Pressure

Allowable bearing pressure is also related to RMR andmay be estimated as per IS 12070.

S.I.5 In stability analysis of rock slopes, strengthparameters are needed in cases of rotational slides.The same may be obtained from RMR parameters

IS 13365 ( Part 1 ) : 1998

which is sum of rating of Items I to IV of Annex 8.The seepage condition should be considered in theanalysis. The same strength parameters are also ap­plicable in case of wedge sliding along discon­tinuous joint sets (see 5.1.6 and Table 2). However,it would be better if strength parameters are obtainedfrom back analysis ofdistressed slopes in similar rockconditions near the site.

5.1.6 Shear Strength ofJointed Rock Masses

The shear strength (e) for poor rock masses are givenby:

't = A (0' + nB

= 0 if 0< 0

where

constants A,T andB are givenin Table 2 both for dryand saturated conditions and Natural Moisture Con­tent (nmc) also. It may be noted that shearstrength decreases significantly after saturation.Block shear tests suggest that shear strength is inde­pendent ofqc for poor rock masses (RMR < 60 and Q< 10). Further, much higher shear strength is likelyto be mobilised in underground openings than thatobtained from block shear tests or Table 2.

Block shear tests on saturated rock blocks shouldbe conducted for design of concrete dams andstability of abutments. For hard and massive rockmasses (RMR > 60), shear strength (t) is governed by(see the first row of Table 2):

'en = A(on + T)B

= 0 if 011 -c 0

where

'to = 'TIqt

an = O'lqc

qt = mean uniaxial compressi ve strengthof intact rock material, and

A,T,B are constants.

In case of underground openings, the increase instrength occurs due to limited freedom of fracturepropagation in openings than that in block sheartest. Another reason for strength enhancement is thatthe in-situ stress along the axis of tunnels and cavernsprestresses rock wedges both in roof and walls. Themobilised uniaxial compressive strength of rock massmay be estimated from the following correlations fortunnels and caverns:

qc mass = 70 YQII3 in kg/cm2; Q S 10; s; = 1;

qc < lOOMPa

tan + = J,/Ja S 1.5

3

IS 13365 ( Part I ) : 1998

Table 1 Enllneerlog Properties 01Rock Mass(Clause 5.1)

lIem Rock Mass Ratina 100-81 80-61 60-41 40-21 <20I. Class I II III IV V2. Classification of rock mass Very good Good Fair Poor Very poor3. Average stand-up time 10years 6 months I week IOh 30 min for

Cohesion of rock mass (kglcm2) 1)for IS m span for 8 m span for Sm span for 2..5 m span I mspan

4. >4 3-4 2-3 1-2 <I5. Angle of internal friction of >45 3S-45 25-35 15-2S 15

rock mass l )

I) Values are applicable for saturated rock masses in slopes.

o

o

VERYGOOD

CROCKIo

2"'---"

1

20 ....---......--....--.....,~--,..,.~~.,

10 ----.....-~.,.8 -----+-..,.6 1-1.------1........,..4 ....----...,

EI

Z

~if)

ow~a=oa.a.:::Jtf)Z::::» 0·5 1-.4...£ ......__.... .....__....__.......

10 10 10 10

STAND -UP TIME I HOURS

10

FIG. I GEOMECHANICS CLASSIFICATION OF ROCK MASSES IN TUNNELS

1-0---------...---.......----r---~,.....,

D

•

o KOTLIE l DAMX TEHRI DAM• CASE HISTORIES

OF BE~IAWSK'

(/)

::J..J

g 0·2i-----'-----6---~~+_---.......------to~

'-

~ 0·8 '-----+------f.----t-----+----iIo------1"0

LLJ

Q:ot-U4 0·6 I-----~----I------+----..-",.....---tu..Zot­U::;)

o O·41------+----......---......---....~---_tUJc:

1

1008020 40 60RMR--

FIG. 2 RELATIONSHIP BETWEEN RMR AND MODULUS REDUCTION FACTOR

4

IS 13365 ( Part 1 ) : 1998

Correlations

where

y = unit weight of rock mus in glee,

Q .= rock mass quality [IS 13365(Part 2)],

J, = joint roughness number, and

J« = joint alteration number.

5.1.7 Estimation ofSupport Pressure

The short-term support pressures for archedunderground openings in both squeezing andnon-squeezing groundconditionsmay be estimatedfrom the following empirical correlation in the case oftunnelling by conventional blasting method usingsteel rib supports:

Proof = (7.5 If.l Jf.s - RMR)nRMR, inkg/cm2

5.1.8 Prediction ofTunnelling Conditions

Ground conditions for tunnelling ean be predicted byusinl the followingcorrelations (s~e Fig. 4):

SINo. GroundConditio,.

i) Self·lupportiD, H < 23.4 tf···. S-o·1 and 1 000 ~.I

Ii) Non-lqUeezlDl 23.4lI·a S-o·1 < H< 275 fIl33 rdJ

ill) Mild aqueezinl 275,.p·33 8-0·1 < H < 4501fU3 g4J.t

iv) Moderate squeezin. 450 !-p.33 ~.I < H < 630 1'P33 B-G·l

v) Hip aqueezinl H > 630 NJ-33 ~.I

In above correlations, N is the rock mass number, asdefined in 4.3. H is the overburden in metres and B isthe tunnel width in metres.

, PRECAUTIONS

where

B = span of opening in metres,

H = overburden or tunnel depth inmetres (> SOm), and

Proof = short-term roof support pressurein kg/cm2

•

The support pressures estimated from Q-system[IS 1336S (Part 2)] are more reliable if StressReduction Factor (SRF) is correctly obtained.

It must be ensured that double accounting forparameters should not be done in analysis of rockstructures and rating of rock mass. If pore waterpressure is being considered in analysis of rockstrucmres, it should not be accounted for in RMR.Similarly, if orientation of joint sets areconsidered in stability analysis of rock structures,the same should not beaccounted for in RMR.

NOTE-Fortbepurposeofeliminatinldoubtsdueto individualjudaements, theralinl for different....,neten shouldbe liven• ran. in preference to a sinsJe value.

90 10010 20 30 40 50 60 10 80~

GEOMECHANICS ROCk MASS RAT'NG (RMR)

1 I I II

-'

· ( 1) E .1: 2RMR -100 I

(2) E =10 (AMR-10)/40 /A· (3) E :It 10 TO 40 LOG 10Q r· Y; ~' ..~

.. iCASE HISTORIES: V'f'~ .+ BIENIAWSKI 1978(1)

~,

• SERAFIM AND vI-

PEREIRA 1983(2) ,?, ~. ...

e¥.-. ~---...~...1--

t~!. ...." ~--.., ~

-- ....-...oo

50

10

20

10

60

90

80

FlO. 3 CORRELATION BETWEEN THE IN-SffU MODULUS OF DBPORMAnON AND mB GEOMBCH~NICS

CLASSIFICATION [ROCK MAssRATINO (RMR)] FOR HARD ROCKS (IGPa =10000 kg/em)

s

Tab

le2

Rec

omm

ende

dM

oh

rEnv

elop

esfo

rJo

inte

dR

ock

Mas

ses

(Cla

use

5.1.

6)

tn=~,

On=~;

oin

kg/c

m2

;t=

0if

o<

0qc

qc

S=d

egre

eof

satu

ratio

n[

aver

age

valu

eof

degr

eeof

satu

ratio

nis

show

nby

Say)

=I,

forc

ompl

etel

ysat

urat

edro

ckm

ass

Roc

kTyp

eL

imes

tone

Sla

te,X

enol

ith,

Phy

llit

eS

ands

tone

,Qua

rtzi

teQ

uali

ty

Goo

dR

ock

Mas

stn

(nm

c)=

0.38

(Q,

+0.

(05)

°.66

9t n

(nm

c)=

0.42(~+

0.0(

4)0.

613

Tn("

RIC

)=

0.44(~+

0.00

3)°·6

95R

MR

=61-

80

Q=

10

40

tn(s

al)

=0.

35(a

.;.

0.00

4)0.

669

'tn(s

at)

=0.

38(Q

a+

0.(0

3)0.

613

fa(s

al)=

0.43(~+

0.(0

2)°.

695

[5=

1][S

=I]

[S=

I)

Fair

Roc

kM

ass

t(nm

c)=2

.60

(0+

1.25

)°·6

62't(

nmc)

=2.7

S(0+

-1.1

5)0.6

75't(

nllM

:)=2.

85(0

+1.

10)°

·611

RM

R=

41-6

0[S

.v=O

.25]

(S.v

=O.1

5]Q

=2·

10't(

sao=

1.95

(0+

1.20

)0.6

62't

(sat

)=2.

15(0

+1.

10)0

.675

't(sa

t)=

2.25

(<1

+1.

05)0

.611

[S=

I][5

=1]

[S=

I]

Poor

Roc

kM

ass

't(nm

c)=

2.50

(0+

0.80

)0.6

46t(

nm

c)=2

.65(

0+0.

75)0

.655

't(ft

IDC

)=2.

85(0

'+0.

70)°

·672

0\

RJl

R=2

1-40

[S.y

::.i).

20]

[S.v

=O.4

0][S

.v=O

.2S]

Q=

0.5-

2't(

51I)

=1.

50(0

+0.

75)°

·646

t(sal

)=1.

75(

0+0.

70)O

.6.5

S1:

(sal)=

2.00

(0+

0.6

5)0.

672

(5=

1][S

=I]

[S=

I]

Ver

yPo

orR

ock

Mas

s't(

a.m

c)=

2.25

(01-

0.65

)00

534

't(1U

IIC)=

2.45

(0+0

.60)

0.53

90.S

46't«

(nlD

C)=

2.65~

0.55

)R

MR

<21

t(sal

)=0.

80(d

)o.S

34't

(sat

)=0.

95(0

)°.5

39't(

sat)

=1.

05(0

)Q

=<

0.5

[5=

1)[S

=I]

[S=

1)

Tra

p,M

etab

8sic

t n(R

IDe)

=0.

50(Q

a+0

.00

3)0

.·[5

.=0.

30]

'to(s

al)=

0.49

(G.+

0.00

2)0.

·[5

=1]

t(nm

c:)=

3.0S

(0

+1'

(1J)

0..

1

[S.v

=O.3

S]t«

51

I)=

2.45

(0+

0.95

)Q.6

91[5

=1]

t«1M

DC)=

3.00

(0+

0.65

)0.6

76

[S.v

=O.IS

]t«

sat)

=2

.25

(0+

0.50

)0.6

76[S

=I)

't({D

BIC

)=2.

90(0

+O

.50)

o.st

It(

(sat

)=1.

25(0

)CL5

4I

(5=

1]

Pil .. ~ Ut~ :II :s. .... '-

' .... i

IS 13365 (Part 1 ) : 1998

4000-ca----......---......----...---~......--_..

+

•

+.

..

+

a

1000 --...--- --~......,---W'I ...-----e800 ---"'"----=:...- ~..-lt--...,..--#--t----__t

500 --...-I-.........,&..-+rwtF--...~~.....----+----....0-1

HB

10L----~-~-'----~~--~~--~0-01 0·1 '-0 10 100 1000

ROCK MASS NUMBER N c Q.SRF

+ SELF SUPPORTING • MODERA1E SQUEEZHG

c NON-SQUEEZING 6 HIGH SQUEEZ~G

o MILD SQUEEZING G) ROCK BURST

a

20 I-----~-----It'+-----+--..oz'-___tr_--__,

20001-----1--------t---.......-~,....___+-~,.. .....

FlO. 4 CRITERIA FOR PREDICTING GROUND CONDITIONS USING ROCK MASS

NUMBER, TONNEL DEPTH AND TuNNEL WIDTH

ANNEX A

(Clause 2)

LIST OF REFERRED INDIAN STANDARDS

11315 Method for the quantitativedescription of discontinuities inrock mass:

(Part 1) : 1981 Orientation

[SNo.

8164: 1978

9143 : 1979

9221 : 1979

Title

Method of determination of pointload strength index of rocks

Method for the determination ofunconfined compressive strength ofrock materials

Method for the determination ofmodulus of elasticity andPoisson's ratio of rock materials inuniaxial compression

IS No. Title

(Part 2) : 1987 Spacing

(Part 3) : 1987 Persistence

(Part 8) : 1987 Seepage

(Part 11): 1987 Core recovery and rock quality

12070: 1987 Code of practice for design andconstruction of shallowfoundation on rock

13365 Quantitative classification"(Part2) : 1992 systems of rock mass-

Guidelines: Part 2 Rock massquality for prediction of supportpressure in undergroundopenings

7

IS 13365 ( Part 1 ) : 1998

ANNEX B

(Clauses 3.1,4.1 and 5.1.5)DATA SHEET FOR GEOMECHANICAL CLASSIFICATION OF ROCK MASSES (RMR)

Name of project .. Location ofsite .Survey conducted by :................ Date- .Type of rock mass unit "'1'" •••••••• Origin of rockmass .

The appropriate rating may be encircled as per site conditions.

RatingIS12742Io

Rating20IS1085

Rating20171383

Point Load Strength>84-82-41-2

Use of uniaxial compressivestrength is preferred

Very wideWideModerateCloseVery close

ExcellentGoodFairPoorVery poor

m SPACING OF DISCONTINUITIESSpacing, m

>20.6-2

0.2-0.60.06-0.2<0.06

I STRENGTH OF INTACT ROCK MATERIAL (MPa)Compressive Strength

Exceptionally strong >2S0Very strong 100-250Strong 50-100Average 2S-50Weak 10-2SVery weak 2-10Extremely weak <2

n ROCK QUALITY DESIGNATION (RQD)RQD

90-10075-9050-7525-50<25

Slickensided wall 5 mm thickrock surface or 1-5 soft gaugemm thick gauge or 5 mm wide1-5 mm wide open- continuousing, continuous discontinuitydiscontinuity

Slightly rough andmoderately fo highlyweathered wall rocksurface, separation-cl mm

NOTE - If more than one set of discontinuity is present and the Spacinl of discontinuities of each set varies, consider the set withlowest rating.

IV CONDITION OF DISCONTINUITIESVery rough and UD- Rough and slightlyweathered wall rock, weathered wall rocktight and discon- surface, separationtinuous, no separation <1 mm

Rating 30 25 20 10

V GROUND WATER CONDITIONInflow per 10 m tunnel length, none <10 10-25(litre/min)Joint water pressure/major 0 0-0.1 0.1-0.2principal stressGeneral description Completely Damp Wet

dryRating IS 10 7VI ORIENTAnON OF DISCONTINUITIESOrientation of tunneVslopeifoundation axis .

Set-I Average strike (from to )Set-2 Average strike (from to )Set-3 Average strike (from to )

o

25-125 >125

0.2-0.5 >0.5

Dripping Flowing

4 0

Dip .Dip .Dip .

8

IS 13365 ( Part 1 ) : 1998

VB ADJUSTMENT FOR JOINT ORIENTATION (see Annex C)

Vf'ryUnfavourable-12-35

FairFavourable Un­Favourable

-2 -5 -10-2 -7 -IS

Use slope mass rating (SMR) as per IS 13365 (Part 3)

VeryFavourableoo

Str;u and dip orienuulonofjoints forTunnelsRaft foundationSlopes

vm ROCK MASS RATING (RMR)

ANNEX C

(Clause 3.1.6)

ASSESSMENT OF JOINT FAVOURABILITY FOR TUNNELS AND DAMS FOUNDATIONS

Table Cl Assessment of Joint Orientation FavourabUlty in Tunnels(Dips are Apparent Dips Alonl Tunnel Axis)

Strike Perpendicular to Tunnel Axis

r

,Drive with Dip

'+ , Drive Against DipAn ,

Strike Parallelto Tunnel Axis

r

Irrespecnveor Strike

Dip 200-45° Dip 20°-45° Dip 45°-900 Dip 0°· 20°

Very favourable Favourable Fair Unfavourable Fair Very unfavourable Fair

Table C2 Assessment of Joint Orientation Favourability forStabUlty or Raft Foundation

,10°·30°

Dip Direction,..

Dip

Upstream Downstream

Veryfavourable

Unfavourable Fair Favourable Very unfavourable

9

IS 13365 ( Part 1 ) : 1998

ANNEX D(Foreword)

COMMITEE COMPOSITION

Rock Mechanics Sectional Committee, CED 48

ChairmanPROF RHAWANI SINGH

MembersASSISTANT RESEARCH OffiCER

DRR. L. CHAUHAN

CUIEF ENGINEER (R & D)DIRECTOR (ENOO) (Alternate)

SHRI DADESHWAR GANGADHAR DHAYAGUDE

SHRI ARUt'J DATTATRAYA JOSHI (Alternate)DR A. K. DU8E

StiRI A. K. 'SONI (Alternate)DR G. S. MEHROTRA

SHRI A. GHOSH (Alternate)DIRECTOR

SHRI KARMVIR

DIRECTOR

SHRI B. M. RAMA GOWDA (Alternate)ENGG MANAGER

DR R. P. KULKARNI

MEMBER SECRETARY

DIRECTOR (C) (Alternate)SHRI D. N. NARESH

SHRI M. D. NAIR

SHRI B. K. SAIOAL (Alterntlte)SI-IRI D. M. PANCUOl.l

DRU. o. DATIR

SCIF.NTIST-IN-CIIARGE

PROF T. RAMAMlIR'n~Y()R G. V. RAO (Alternate)

SHRI S. I). BHARAnlA

SHRI T. S. NARAYANA DAS (Alternate)DM A. K. DHAWAN

SIIRI JITINDRA SINGH

SItRI D. K. JAIN (Alternate)SIIRI P. J. RAo

SI-IRI D. S. TOLIA (Alternate)SURI RANJODH SINGH

DRP. K. JAIN

DRM. N. VILADKAR (Alternate)DIRECTOR & SECRETARY

I)R V. K. SINHA

DR V. V. S. RAO

SHRI U. S. RAJVANSHI

DR J. L. JETlIWA

DR V. M. SHARMA

SHRI VINOD KUMAR.

Director (Civ Engg)

RepresentingUniversity of Roorkee, Roorkee

Irrigation Department, UPHimachal Pradesh State Electricity Board, ShimlaIrrigation Department. Haryana

Asia Foundations and Constructions Ltd. Mumbai

Central Mining Research Institute (CSIR), Roorkee

Central Building Research Institute (CSIR), Roorkee

Geological Survey of India. CalcuttaIrrigation and Power Department. PunjabCentral Water and Power Research Station. Pune

Hindustan Construction Co Ltd. MumbaiIrrigation Department, Maharashtra. NasikCentral Board of Irrigation and Power. New Delhi

National Thermal Power Corporation Ltd, New DelhiAssociated Instrument Manufacturers (I) Pvt Ltd. New Delhi

Irrigation Department. Government of Gujarat, GandhinagarGujarat Engineering Research Institute, VadodaraNational Geophysical Research Institute. HyderabadIndian Institute of Technology. New Delhi

Karnataka Engineering Research Station, Krishna Rajasager, Kamataka

Central Soil and Materials Research Station, New DelhiEngineer-in-Chiers Branch. New Delhi

Central Road Research Institute. New Delhi

Naptha Jhakri Power Corporation. Shimla

University of Roorkee, Roorkee

Central Ground Water Board, New DelhiCentral Mining Research Institute. DhanbadIndian Geotechnical Society, New DelhiIn personal capacity (KC-J8, Kavinagar, Ghal.;abad, UP)

In personal capacity (CMRI, Nagpur)

In personal capacity (ATES. Hew Delhi)

Director General, BIS (Ex-officio Member)

Member Secretary

SHR' W. R. PAUL

Joint Director (Civ Engg). BIS

( Continued on page 11)

10

IS 13365 (Part 1 ) : 1998

( Continued from page 10)

Field Testing of Rock Mass and Rock Mass Classification Subcommittee, CED 48: 1

ConvenerSHRI U. S. RAJV ANSHI

KC-38. Kavinagar. Ghaziabad. UP

M,mbersSHRI VrrrAL RAMORO. S. MEHROTRA

SHRI U. N. SINHA (Alternate)DIRECTOR

CHIEF ENOINEERINO-eUM-DIRECTOR

ReSEARCH OFFICER (Alternate)SHR) 8. M. RAMA GOWDA

SHRI 8. K. SAHA (Alternate)GENERAL MANAOER (DESIGN)

DR GOPAL OHAWAN (Alternate)SHRI D. M. PANCHOLI

DRU. D. DATIRORO. V. RAO

DR K. K. GUPTA (Alternate)DRR. 8. SINOH

DR P. K. JAIN

DRANBALAOAN (Alternate)RESEARCH OFFICER (SR & P DIVISION)

CHIEF ENGINEER (DAM DESIGN)

Assn ENGINEER (lRI) (Alternate)REPRESENTATIVE

ORA. K. DUDE

DR V. M. SHARMA

RepresentingIrrigation Department, HaryanaCentra18uilding Research Institute (CSIR). Roorkee

Geological Survey of India, CalcuttaIrrigation and Power Department, Punjab

Central Water & Power Research Station, Pune

National Hydro Electric Power Corporation Ltd, Faridabad

Irrigation Department. Government ofOujarat, GandhinagarGujarat Engineering Research Institute, VadodaraIndian Institute of Technology, New Delhi

Central Soil and Materials Research Station, New DelhiUniversity of Roorkee, Roorkee

Mahara.c;htraEngineering Research Institute, NasikU.P.lnigation Research Institute, Roorkee

Indian School of Mines. DhanbadCentral Mining Research Institute. DhanbadIn personalcapacity (ATES. N~w D~lhi)

Member.fDRR. K. GOEL

PROF 8HAWANI SINGH

Panel for Rock Mass Clasification, CED 48 : IIPI

Central Mining Research Institute. RoorkeeUniversity of Roorkee, Roorkee

II

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