Is 875 Part 2 1987 Code of Practice for Design Loads (Othe

8/3/2019 Is 875 Part 2 1987 Code of Practice for Design Loads (Othe

1/20

Indian Standard

IS : 875 ( Part 2 ) - 1987(Reaffirmed 1997)

CODE OF PRACTICE FOR

DESIGN LOADS (OTHER THAN EARTHQUAKE)FOR BUILDINGS AND STRUCTURES

PART 2 IMPOSED LOADS

(Second Revision)~-Sixtll Reprint JUNE 1998

UDC 624~042.3 : 006.76

@ Copyright 1989

B U R E A U O F I N D I A N S T A N D A R D SM A N A K B H AVA N , 9 B A H A D U R S H A H Z A FA R M A R G

( Reaffirmed 2003 )


2/20


3/20

IS : 875 ( Part 2 ) - 1987

( Continuedfrom page 1 )

MembersS H R I M. C. S HARMAS H R I K. S. SRINIVASAN

S H R I A. K. L AL ( Alternate )SHRI SUSHJL KLIMAR

SHRI G. RAMAN,Director ( Civ Engg )

RepresentingIndia Meteorological Department, New DelhiNational Buildings Organization, New Delhi

National Building Construction Corporation, Limited,New Delhi

Director General, BIS ( Ex-officio Member )

Secretary

S HR I B. R. NARAYANAPPADeputy Director ( Civ Engg ), BIS

Panel on Loads ( Other than Wind Loads ), BDC 37 : P3

Convener

D R T. N. SUBBA RA OD R S. V. L ONKAR ( Alternate )

MembersD R T. V. S. R. APPA RA O

D R M. N. K ESHAVA R AO ( Alternate )S H R I S. R. KULKARNISHRI M. L. MLHTA

S H R I S . K. D AT T A ( Alternate )D R C . N . S R I N I VA S A NS U P E R I N T E N D I N G E N G I N E E R ( D )

E X E C U T I V E E N G I N E E R ( D ) VII ( Alternate )D R H. C. V I S V E S V A R A Y A

Gammon India Limited, Bombay

Structural Engineering Research Centre, CSIR Campus,Madras

M. N. Dastur & Co Ltd, CalcuttaMetallurgical & Engineering Consultants ( India ) Ltd.

Ranchi

M/s C. R. Narayana Rao, MadrasCentral Public Works Department ( Central Designs

Organization ), New Delhi

National Council for Cement and Building Materials,New Delhi


4/20


5/20

IS : 875 ( Part 2 ) - 1987

Indian Standard

CODE OF PRACTICEDESIGN LOADS (OTHER THAN

FOREARTHQUAKE)

FOR BUILDINGS AND STtiUCTURESPART 2 IMPOSED LOADS

(Second Revision)

0 . F O R

0.1 This Indian Standard ( Part 2 ) ( SecondRevision ) was adopted by the Bureau of IndianStandards on 31 August 1987. after the draftfinalized by the Structural Safety Sectional Com-mittee had been approved by the Buildmg Divi-sion Council.0.2 A building has to perform many functions

satisfactorily. Amongst these functions are theutility of the building for the intended useand occupancy, structural safety, fire safety;and compliance with hygienic, sanitation, venti-lation and day light standards. The design of the building is dependent upon the minimumrequirements prescribed for each of the abovefunctions. The minimum requirements pertainingto the structural safety of buildings are beingcovered in this Code by way of laying downminimum design loads which have to be assumedfor dead loads, imposed loads, snow loads andother external loads, the structure would berequired to bear. Strict conformity to loadingstandards recommended in this Code, it is hoped,

will not only ensure the structural safety of thebuildings which are being designed and construct-ed in the country and thereby reduce the hazardsto life and property caused by unsafe structures,but also eliminate the wastage caused by assumingunnecessarily heavy loadings.

0.3 This Code was first published in 1957 for theguidance of civil engineers, designers and archi-tects associated with the planning and design of buildings. It included the provisions for the basicdesign loads ( dead loads, live loads, wind loadsand seismic loads ) to be assumed in the designof buildings. In its firs! revision in 1964, thewind pressure provisions were modified on the

basis of studies of wind phenomenon and itseffects on structures, undertaken by the specialcommittee in consultation with the IndianMeteorological Department. In addition to this,new clauses on wind loads for butterfly typestructures were included; wind ,pressure coeffi-cients for sheeted roofs, both curved and sloping,were modified; seismic load provisions were delet-ed ( separate code having been prepared ) andmetric system of weights and measurements wasadopted.

E W O R D

0.3.1 With the increased adoption of the Code,a number of comments were received on the pro-visions on live load values adopted for differentoccupancies. Simultaneously live load surveyshave been carried out in America and Canada toarrive at realistic live loads based on actual deter-mination of loading ( movable and immovable )in different occupancies. Keeping this in viewand other developments in the field of windengineering, the Sectional Committee responsiblefor the preparation of the Code has decided toprepare the second revision of IS : 875 in thefollowing five parts :

Part 1 Dead loadsPart 2 Imposed loadsPart 3 Wind loadsPart 4 Snow loadsPart 5 Special loads and load combinationsEarthquake load is covered in a separate

standard, namely IS : 1893-1984* which shouldbe considered along with above loads.

0.3.2 This Code ( Part 2 ) deals with imposedloads on buildings produced by the intendedoccupancy or use. In this revision, the followingimportalit changes have been made:

a) The use of the term live load has beenmodified to imposed load to cover notonly the physical contribution due topersons but also due to nature of occu-pancy, the furniture and other equipmentswhich are a part of the character of theoccupancy.

b) The imposed loads on floors and roofshave been rationalized based on the

codified data available in large numberof latest foreign national standards, andother literature. Further, these valueshave been spelt out for the major occu-pancies as classified in the NationalBuilding Code of India as well as thevarious service areas appended to the majoroccupancies.

*Criteria for earthquake resistant design of structures(fourth revision ).

4


6/20

C)

4

e)

f >

g>

The reduction of imposed loads fordesign of vertical supporting membersin multi-storeyed b u i l d i n g s h a s b e e nfurther increased from 40 to 50 percent.Provision has been included for signposting of loads on floors in view of the different loadings specif ied. for

different occupancies and to avoid possi-ble misuse in view of conversion of occupancies.The value of loads on parapets andbalustrades have been revised with itseffect taken both in the horizontal andvertical directions.In the design of dwelling units plannedan d executed in accordance withIS : 8888-1979*, an imposed load of 1.5kN/m* is allowed.SI Units have been used in the Code.

0.3.3 The buildings and structural systems shallprovide such structural integrity that the hazardsassociated with progressive collapse such as thatdue to local failure caused by severe overloads orabnormal loads not specifically covered thereinare reduced to a level consistent with goodengineering practice.

0.3.4 Whenever buildings are designed for futureadditions of floor at a later date, the number of storeys for which columns/walls, foundations, etc,have been structurally designed may be posted ina conspicuous place similar to posting of floorcapacities and both could be placed together.

0.4 The Sectional Committee responsible for thepreparation of this Code has taken into account- -

*Guide for requirements of low income housing.

IS : 875 ( Part 2 ) - 1987

the prevailing practices in regard to loadingstandards followed in this country by the variousmunicipal authorities and has also taken note of the developments in a number of countries abroad.In the preparation of this Code, the followingnational standards have been examined :

a) BS 6399 : Part 1 : 1984 Design Loading forBuildings Part I: Code of Practice forDead and Imposed Loads. British Stand-ards Institution.

b) AS : 1170, Part 1-1983 - SAA LoadingCode, Part I Dead and Live Loads.Australian Standards Institution.

c) NZS 4203-1976 New Zealand StandardGeneral Structural Design and DesignLoading for Building. Standards Associa-tion of New Zealand.

d) ANSI. A 58.1 - 1982American StandardBuilding Code Requirements for Minimum

Design Loads in Buildings and OtherStructures.

e)

f )

!?I

h)

National Building Code of Canada ( 1977 )Supplement No. 4. Canadian StructuralDesign Manual.

DIN 1055 Sheet 3 - 1971 Design Loadsfor Buildings - Live Load ( West GermanLoading Standards ).

IS0 2103-1986 Loads due to use andoccupancy in residential and public build-ings.

IS0 2633-1974 Determination of Impos-ed Floor Loads in Production Buildingsand Warehouses. lnternational Organiza-tion for Standardization.

1. SCOPE

1.1 This standard ( Part 2) covers imposed loads*( live loads ) to be assumed in the design of build-ings. The imposed !oads, specified herein, areminimum loads which should be taken into con-sideration for the purpose of structural safety of buildings.

1.2 This Code does not cover detailed provisionsfor loads incidental to construction and specialcases of vibration, such as moving machinery,heavy acceleration from cranes, hoists and thelike. Such loads shall be dealt with individuallyin each case.

2. TERMINOLOGY

2.0 For the purpose of this Code, the followingdefinitions shall apply.

*The word imposed load is used through out insteadof live load which is synonymous.

2.1 Imposed Load - The load assumed to beproduced by the intended use or occupancy of abuilding, mcluding the weight of movable parti-tions, distributed, concentrated loads, load dueto impact and vibration, and dust load but ex-cluding wind, seismic, snow and other loads dueto temperature changes, creep, shrinkage, differ-ential settlement, etc.2.2 Occupancy or Use Group - The principaloccupancy for which a building or part of a build-ing is used or intended to be used; for the pur-pose of classification of a building according tooccupancy, an occupancy shall be deemed toinclude subsidiary occupancies which are contin-gent upon it. The occupancy classification isgiven from 2.2.1 to 2.2.8.

2.2.1 Assembly Buildings - These shall includeany building or part of a building where groupsof people congregate or gather for amusement,recreation, social, religious, patriotic, Civil, traveland similar purposes, for example, theatres,motion picture houses, assembly halls, city halls,

5


7/20

IS : 875 ( Part 2 ) - 1987

marriage halls, town halls, auditoria, exhibitionhalls, museums, skating rinks, gymnasiums,restaurants ( also used as assembly halls ), placesof worship, dance halls, club rooms, passengerstations and terminals of air, surface and otherpublic transportation services, recreation piersand stadia, etc.

2.2.2 Business Buildings-

These shall includeany building or part of a building, which is used fortransaction of business ( other than that coveredby 2.2.6 ); for the keeping of accounts and recordsfor similar purposes; offices, banks, professionalestablishments, court houses, and libraries shallbe classified in this group so far as principal func-tion of these is transaction of public businessand the keeping of books and records.

2.2.2.1 Ofice b u i l d i n g s - The buildingsprimarily to be used as an office or for office pur-poses; office purposes include the purpose of administration, clerical work, handling money,

telephone and telegraph operating and operatingcomputers, calculating machines; clerical workincludes writing, book-keeping, sorting papers,typing, filing, duplicating, punching cards ortapes, drawing of matter for publication and theeditorial preparation of matter for publication.

2.2.3 E d u c a t i o n a l B u i l d i n g s - These shallinclude any building used for school, college orday-care purposes involving assembly for instruc-tion, education or recreation and which is notcovered by 2.2.1.

2.2.4 Industrial Buildings - These shall includeany building or a part of a building or structure inwhich products or materials of various kinds andproperties are fabricated, assembled or processedlike assembly plants, power plants, refineries, gasp!ants, mills, dairies, factories, workshops, etc.

2.2.5 Institutional Buildings - These shall includeany building or a part thereof, which isused forpurposes, such as medical or other treatment incase of persons suffering from physical and mentalillness, disease or infirmity; care of infants, con-valescents of aged persons and for penal or cor-rectional detention in which the liberty of theinmates is restricted. Institutional buildingsordinarily provide sleeping accommodation forthe occupants. It includes hospitals, sanitoria,custodial institutions or penal institutions like jails, prisons and reformatories.

2.2.6 Mercantile Buildings -These shall includeany building or a part of a building which is usedas shops, stores, market for display and sale of merchandise either wholesale or retail. Office,storage and service facilities incidental to the saleof merchandise and located in the same buildingshall be included under this group.

2.2.7 Residential Buildings - These shall includeany building in which sleeping accommodation is

provided for normal residential purposes with orwithout cooking or dining or both facilities( except buildings under 2.2.5). It includes one

multi-family dwellings, apartment housesphats ), lodging or rooming houses, restaurants,hostels, dormitories and residential hotels.

2.2.7.1 Dwellings - These shall include anybuilding or. p;i:t occupied by members of single/ multi-family units with independent cookingfacilities. These shall also include apartmenthouses ( flats ).

2.2.8 Storage Buildings - These shall includeany building or part of a building used primarilyfor the storage or sheltering of goods, wares ormerchandize, like warehouses, cold storages,freight depots, transity sheds, store houses, gara-ges, hangers, truck terminals, grain elevators,barns and stables.

3. IMPOSED LOADS ON FLOORS DUE TOUSE AND OCCUPANCY

3.1 Imposed Loads - The imposed loads to beassumed in the design of buildings shall be thegreatest loads that probably will be produced bythe intended use or occupancy, but shall not beless than the equivalent minimum loads specifiedin Table 1 subject to any reductions permittedby 3.2.

Floors shall be investigated for both theuniformly distributed load ( UDL ) and the cor-responding concentrated load specified in Table 1and designed For the most adverse effects but

they shall not be considered to act simultaneously.The concentrated loads specified in Table 1 maybe assumed to act over an area of 0.3 x 0.3 m.However, the concentrated loads need notbe considered where the floors are capable of effective lateral distribution of this load.

All other structural elements shall be investi-gated for the effects of uniformly distributed loadson the floors specified in Table 1.

N OT E 1 - Where in Table 1, no values are given forconcentrated load, it may be assumed that the tabula-ted distributed load is adequate for design purposes.

N OT E 2 - The loads specified in Table I are equiva-lent uniformly distributed loads on the plan area andprovide for normal effect of impact and acceleration.They do not take into consideration special concentra-ted loads and other loads.

N OT E 3 - Where the use of an area or floor is notprovided in Table 1, the imposed load due to the useand occupancy of such an area shall be determinedfrom the analysis of loads resulting from:

a!

b)

weight of the probable assembly of persons;

weight of the probable accumulation of equipmentand furnishing;

4 weight of the probable storage materials; and

4 impact factor, if any.

6


8/20


9/20


10/20

I S : 875 ( Par t 2 ) - 1987

TABLE 1 IMP OSED FLOOR LOADS FOR DIFFERENT O CCUPANCIES - C o d

SL O CCUPANCY C LASSIFICATIONNo.

( 1 ) ( 2 )

c) Dining rooms, cafeterias andrestaurants

d) Toilets and bathrooms

e) X-ray rooms, operating rooms,general storage areas -to be cal-culated but not less than

f) Office rooms and OPD rooms

g) Corridors, passages, lobbies andstaircases including fire escapes -as per the floor serviced but not lessthan

h) Boiler rooms and plant rooms - tobe calculated but not less than

j) Balconies

iv) ASSEMBLY BUILDINGS

a) Assembly areas:

1) with fixed seatsz

2) without fixed seats

b) Restaurants ( subject to assembly ),museums and art galleries andgymnasia

c) Projection rooms

d) Stages

e) Office rooms, kitchens and laundriesf) Dressing rooms

g) Lounges and billiards rooms

h) Toilets and bathrooms j) Corridors, passages, staircases

including fire escapes

k) Balconies

m) Boiler rooms and plant roomsincluding weight of machinery

n)- Corridors, passages subject to loadsgreater than from crowds, such aswheeled vehicles, trolleys and thelike. Corridors, staircases and pas-sages in grandstands

UNIFORMLY CONCENTRATEDDISTRIBUTED

LOAD ( UDL )

( 3 )kN/m

3.0t

2.0

30

25

40

50

LOAD

( 4 )kN

2.7

-45

27

45

4.5

Same as the rooms towhich they give access butwith a minimum of 4.0

15 per metre run concen-trated at the outer edge

40

50

4.0

5 ' 0

50

3020

2.0

2.0

40

Same as rooms to whichthey give access but witha mintmum of 4.0

75

50

-

3.6

4.5

-

4.5

4.518

2.7-

4.5

1.5 per metre run concen-trated at the outer edge

45

4.5

v) BUSINESS AND OFFICE BUILDINGS ( see ulso 3.1.2 )

a) Rooms for general use with separate 25storage

27

b) Rooms &thout separate storage 4.0 4.5

I Continued )

9


11/20

IS : 875 ( Part 2 ) - 1987

TABLE 1 IMPOSED FLOOR LOADS FOR DIFFERENT OCCUPANCIES - Contd

SL O CCUPANCY C LASSIFICATION UNTFORMLY C ONCENTRATEDNo. D ISTRIBUTED L OA D

L OAD ( UDL )

(1) (2) ( 3 ) ( 4 )

kN/m kNec) Banking halls 30 2.7

d) Business computing machine rooms( with fixed computers or similarequipment )

e) R ecords/files store rooms andstorage space

35 4.5

50 4.5

f) Vaults and strong room - to becalculated but not less than

50 4.5

g) Cafeterias and dining rooms

h) Kitchens

j) Corridors, passages, lobbies andstaircases including fire escapes - asper the floor serviced (excludingstores ) but not less than

k) Bath and toilet rooms

m) Balconies

3.0t 2.7

3.0 2.7

4.0 4.5

2.0

Same as rooms to whichthey give access but witha minimum of 4.0

.-.

I.5 per metre run concen-trated at the outer edge

n) Stationary stores

p) Boiler rooms and plant rooms - tobe calculated but not less than

q) Libraries

vi) MERCANTILE BUILDINGS

a) Retail shops

b) Wholesale shops - to be calculatedbut not less than

c) Office rooms

d) Dining rooms, restaurants and cafe-terias

e) Toilets

f) Kitchens and laundries

g) Boiler roooms and plant rooms -to be calculated but not less than

h) Corridors, passages, staircasesincluding fire escapes and lobbies

j) Corridors, passages, staircases subject to loads greater than fromcrowds, such as wheeled vehicles,trolleys and the like

k) Balconies

40 for each metre of storage height

50

see Sl No. ( ii )

4.0 3.6

60 4.5

25

30t

2.0

30

50

4.0

5.0

27

2.7

-

45

6.7

4.5

4.5

Same as rooms to whichthey give access but witha minimum of 4.0

1.5 per metre run concen-trated at the outer edge

10


12/20


13/20

IS : 875 ( Part 2 ) - 1Yar

N OTE 4 - While selecting a particular loading, thepossible change in use or occupancy of the buildingshould be kept in view. Designers should not neces-sarily select in every case the lower loading appropriateto the first occupancy. In doing this, they might intro-duce considerable restrictions in the use of the build-ing at a later date and thereby reduce its utility.

N OTE 5 - The loads specified herein which arebased on estimations, may be considered as thecharacteristic loads for the purpose of limit statemethod of design till such time statistical data areestablished based on load surveys to be conducted inthe country.

N OTE 6 - When an existing building is altered byan extension in height or area, all existing structuralparts affected by the addition shall be strengthened,where necessary, and all new structural parts shall bedesigned to meet the requirements for building there-after erected.

NOTE 7 - The loads specified in the Code does notinclude loads incidental to construction. Therefore,close supervision during construction is essential toeusure that overloading of the building due to loadsby way of stacking of building materials or use of equipment ( for example, cranes and trucks ) duringconstruction or loads which may be induced by floor tofloor propping in multi-storeyed construction. does notoccur. However: if construction loads were of shortduration, permissible increase in stresses in the case of working stress method or permissible decrease in loadfactors in limit state method, as applicable to relevantdesign codes, may be allowed for.

N OTE 8 - The loads in Table 1 are grouped togetheras applicable to buildings having separate principaloccupancy or use. For a building with multiple occu-pancies, the loads appropriate to the occupancy withcomparable use shall be chosen from other occupancies.

N OTE 9 -- Regarding loading on machine roomsinc!uding storage space used for repairing liftmachines, designers should go by the recommendationsof lift manufacturers for the present. Regarding theloading due to false ceiling the same should be con-sidered as an imposed load on the roof/floor to whichit is fixed.

3.1.1 Load Application - The uniformly distri-buted loads specified in Table 1 shall be appliedas static loads over the entire floor area underconsideration or a portion of the floor area which-ever arrangement produces critical effects on thestructural elements as provided in respectivedesign codes.

In the design of floors, the concentrated loadsare considered to be applied in the positions whichproduce the maximum stresses and where deflec-tion is the main criterion, in the positions whichproduce the maximum deflections Concentratedload, when used for the calculation of bending andshear are assumed to act at a point. When usedfor the calculation of local effects, such as crush-ing or punching, they are assumed to act over anactual area of application of 0.3 x 0.3 m.

3.1.2 Loads Due to Light Partitions - In officeand other buildings where actual loads due tolight partitions cannot be assessed at the time of planning, the floors and the supporting structuralmembers shall be designed to carry, in addition toother loads, a uniformly distributed load persquare metre of not less than 339 percent of

weight per metre run of finished partitions,subject to a minimum of 1 kN/m2, provided totalweight of partition walls per square metre of thewall area does not exceed 1.5 kN/m2 and thetotal weight per metre length is not greater than4.0 kN.

3.2 Reduction in Imposed Loads on Floors

3.2.1 For Floor Supporting Structuraal Members -Except as provided for in 3.2.1.1, the followingreductions in assumed total imposed loads onfloors may be made in designing columns, loadbearing walls, piers, their supports and founda-tions.

Number of Floors ( I n & d - Reduction in Totaling the Roof) to be Carried Distr ibuted Imposed

by Member under Load on all Floors toConsideration be Carried by the

Member under Consideration

( Percent )

1

2

3

4

5 to 10Over 10

0

10

20

30

40

50

3.2.1.1 N O reduction shall be made for anyplant or machinery which is specifically allowedfor, or in buildings for storage purposes, ware-houses and garages. However, for other buildingswhere the floor is designed for an imposed floorload of 5.0 kN/m or more, the reductions shownin 3.2.1 may be taken, provided that the loadingassumed is not less than it would have been if allthe floors had been designed for 5.0 kNjmZ withno reductions.

N OTE -In case if the reduced load in the lowerfloor is lesser than the reduced load in the upper floor,then the reduced load of the upper floor will beadopted.

3.2.1.2 An example is given in Appendix Aillustrating the reduction of imposed loads in amulti-storeyed building in the design of columnmembers.

3.2.2 For Reams in Each Floor Level - Wherea single span of beam, girder or truss supportsnot less than 50 m2 of floor at one general level,the imposed floor load may be reduced in thedesign of the beams, girders or trusses by 5 per-cent for each 50 ma area supported subject to amaximum reduction of 25 percent. However, noreduction shall be made in any of the followingtypes of loads:

a) Any superimposed moving load,

12


14/20


15/20

IS : 875 ( Part 2 ) - 1987

along the line of seats and O-15 kN per linearmetre perpendicular to the line of the seats.These loadings need not be applied simultaneously.Platforms without seats shall be designed to resista minimum horizontal force of O-25 kN/m of plan area.

6. LOADING EFFECTS DUE TO IMPACTAND VIBRATION

6.0 The crane loads to be considered under impos-ed loads shall include the vertical loads, eccentri-city effects induced by vertical loads, impact

factors, lateralacting acrossrespectively.

and longitudinal braking forcesand along the crane rails

6.1 Impact Allowance for Lifts, Hoists and Machi-nery - The imposed loads specified in 3.1 shall beassumed to include adequate allowance for ordi-nary impact conditions. However, for structurescarrying loads which induce impact or vibration,as far as possible, calculations shall be made forincrease in the imposed load, due to impact orvibration. In the absence of sufficient data for

TABLE 2 IMPOSED LOADS ON VARIOUS TYPES OF ROOFS

SL TYPE OF R OOFNo.

(1) (2)

i) Flat, sloping or curved roof with slopes up to and includ-ing 10 degreesa) Access provided

( Clause 4.1 )

U NIFORMLY D ISTRIBUTEDIMPOSED LOAD M EASUKED

ON PLAN ARE A

(3)

15 kN/m

b) Access not provided 0.75 kN/m2except for maintenance

ii) Sloping roof with slope greaterthan 10 degrees

iii) Curved roof with slope of lineobtained by joining spring-ing point to the crown withthe horizontal, greater than10 degrees

For roof membrane sheets or pur-lins-0.75 kN/mZ les s 0.02 kN/mfor every degree increase in slopeover 10 degrees

( O;le ; 0.52 ya ) kN/m

y = h/lh = the height of the highest

point of the structuremeasured from its spring-ing; and

I = ;hord width of the roof singly curved and

shorter of the two sidesif doubly curved

Alternatively, where structuralanalysis can be carried out forcurved roofs of all slopes in asimple manner applying the lawsof statistics, the curved roof shallbe divided into minimum 6 equalsegments and for each segmentimposed load shall be calculatedappropriate to the slope of thechord of each segment as given in( i ) rind ( ii ) above

M INIMUM IMPOSED LOA DM EASURED ON PLA N

(4)

3.75 kN uniformly distributedover any span of one metrewidth of the roof slab and 9 kNuniformly distributed over thespan of any beam or truss orwall

1.9 kN uniformly d is t r ibutedover any span of one metrewidth of the roof slab and 4.5kN uniformly distributed overths span of any beam or trussor wall

Subject to a m i n i m u m o f 0.4 kN,W

Subject to a minimum of 0.4 kN/m*

N OTE 1 - The loads given above do not include loads due to snow, rain, dust collection, etc. The roof shallbe designed for imposed loads given above or for snow/rain load, whichever is greater.

NOTE 2 - For special types of roofs with highly permeable and absorbent material, the contingency of roof material increasing in weight due to absorption of moisture shall be provided for.

14


16/20

IS : 875 ( Part 2 ) - 1987

TABLE 3 HORIZONTAL LOADS ON PARAPETS, PARAPET WALLS AND BALUSTRADES

( Cfause 5.1 )

SLNo.

U SAGE A R E A INTENSITY OF HORIZONTALLOAD , kN/m RUN

(2)

Light access stairs-gangways and the like notmore than 600 mm wide

(3)

0.25

ii) Light access stairs. gangways and thelike, more than 600 mm wide: stairways,landings, balconies and parapet walls( private and part of dwellings )

0.35

iii) All other stairways, landings and balco-nies, and all parapets and handrails toroofs except those subject to overcrow-ding covered under ( iv )

0.75

iv) Parapets and balustrades in place of assembly, such as theatres, cinemas,churches, schools, places of entertain-ment. sports, buildings likely to be over-

crowded

225

N O T E - In the case of guard parapets on a floor of multi-storeyed car park or crash barriers provided in

certain buildings for fire escape, the value of imposed horizontal load ( together with impact load ) may bedetermined.

such calculation, the increase in the imposed loads 6.2 Concentrated Imoosed Loads with Imuact andshall be as follows:

Structures

For frames supporting liftsand hoists

For foundations, footingsand piers supporting liftsand hoisting apparatus

For supporting structuresand foundations for lightmachinery, shaft or motorunits

For supporting structuresand foundations for reci-procating machinery orpower units

Impact Allowance

Min100 percen

40 percent

Vibration - Concentrated imposed loads withimpact and vibration which may be due to instal-led machinery shall be considered and providedfor in the design. The impact factor shall not beless than 20 percent which is the amount allow-able for light machinery.

20 percent

50 percent

6.2.1 Provision shall also be made for carryingany concentrated equipment loads whiIe theequipment is being installed or moved for servic-mg and repairing.

6.3 Impact Allowances for Crane Girders - Forcrane gantry girders and supporting columns, thefollowing allowances shall be deemed to cover allforces set up by vibration, shock from slipping orslings, kinetic action of acceleration, and retarda-tion and impact of wheel loads :

Type of Load Additional Load

a) Vertical loads for electric overhead cranes 25 percent of maximum static loads forcrane girders for all classes of cranes

25 percent for columns supporting ClassIJI and Class IV cranes

10 percent for columns supporting Class Iand Class II cranes

No additional load for design of founda-tions

b) Vertical loads for hand operated cranes 10 percent of maximum wheel loads forcrane girders only

(Continued)

15


17/20

IS : 813 ( rart L ) - 1Y17

c) Horizontal forces transverse to rails:

1) For electric overhead cranes withtrolley having rigid mast for suspen-sion of lifted weight ( such as soakercrane, stripper crane, etc )

2) For all other electric overhead cranesand hand operated cranes

d) Horizontal traction forces along therails for overhead cranes, either electri-cally operated or hand operated

-10 pe rcen t o f we igh t o f c r ab and t heweight lifted by the cranes, acting on anyone crane track rail. acting in either direc-tion and equally distributed amongst allthe wheels on one side of rail track

For frame analysis this force shall beapplied on one side of the frame at a timein either direction

-5 percent of weight of crab and the weightlifted by the cranes, acting on anyonecrane track rail, acting in either directionand equally distributed amongst thewheels on one side of rail track

For the frame analysis, this force shall beapplied on one side of the frame at a timein either direction

-5 percent of all static wheel loads

Forces specified in ( c ) and ( d ) shall beconsidered as acting at the rail level and beingappropriately transmitted to the supporting sys-tem. Gantry girders and their vertical supportsshall be designed on the assumption that either of the horizontal forces in ( c ) and ( d ) may act atthe same time as the vertical load.

NOTE-&e IS : 807-l!%+ for classification ( ClaSSeS1 to 4 ) of cranes.

6.3.1 Overloading Factors in Crane SupportingS t t u t w es - For all ladle cranes and chargingcranes, where there is possibility of overloading

from production considerations, an overloadingfactor of 10 percent of the maximum wheel load-ing shall be taken.

6.4 Crane Load Combinations - In the absenceof any specific indications, the load combinationsshall be as indicated in the following sub-clauses.

6.4.1 Vertical Loads - In an aisle, where morethan one crane is in operation or has provisionfor more than one crane in future, the followingload combinations shall be taken for verticalloading:

a)

b)

Two adjacent cranes working in tandemwith fu l l load and wi th overloadmgaccording to 6.3( a ); and

For long span gantries, where more thanone crane can come in the span, the girdershall be designed for or.e crane fully loadedwith overloading according to 6.3(a)plus as many loaded cranes as can be

-*Code of practice for design, manufacture, erection

and testing ( structural portion ) of cranes and hoists(first revision ).

accommodated on the span but withouttaking into account overloading accordingto 6.3( a ) to give the maximum effect.

6.4.2 Latera l Surge - For design of columnsand foundations, supporting crane girders, thefollowing crane combinations shall be considered:

a)

b)

6.4.3

For s ingle-bay f rames - Effect of onecrane in the bay giving the worst effectshall be considered for calculation of surgeforce, and

For mul t i -bay f r ames - Effect of twocranes working one each in any of twobays in the cross-section to give the worsteffect shall be considered Ior calculationof surge force.

Tractive Force

6.4.3.1 Where one crane is in operation withno provision for future crane, tractive force fromonly one crane shall be taken

6.4.3.2 Where more than one crane is inoperation or there is provision for future crane,tractive force from two cranes giving maximumeffect shall be considered.

N OTE - Lateral surge force and longitudinal trac-tive force actingacross and along the crane rail respec-tively, shall not be assumed to act simultaneously.However, if there is only one crane in the bay, thelateral and longitudinal forces may act together simul-taneously with vertical loads.

7. OTHER LOADS

7.1 Dead Load - Dead load includes the weightof all permanent components of a building includ-ing walls,partitions, columns, floors, roofs, finishes

16


18/20

IS:875(Part2)-1987

and fixed permanent equipment and fittings thatare an integral part of the structure. Unit weightof building materials shall be in accordance withIS : 875 ( Part 1 )-1988:

7.2 Wind Load -- The wind load on buildings/ structures shall be in accordance with IS : S75( Part 3 )-1988.

7.3 Seismic I;;;;t dfeismic load on buildings/ structures , in accordance with

IS : 1893-1984*.

7.4 Snow Load - Snow loading on buildingsshall be in accordance with IS : 875 ( Part 4 )-I 988.

7.1 Special Loads and Load Combinations-

Special loads and load combinations shall be i naccordance with 1s : 875 ( Part 5 )-1988.

*Criteria for eartnquakeresistant design of structures( fc;ur/h r e v i s i o n ).

A P P E N D I X A

( Clause 3.2.1.2 )

ILLUSTRATIVE EXAMPLE SMOWING REDUCTION OF UNIFORMLY DISTRIBUTEDIMPOSED FLOOR LOADS IN MULTI-STOREYED BUII,DINGS FOR DESIGN

OF COLUMNS

A-l. I he total imposed loads from different floorlevels ( including the roof) coming on the central

Floor loads do.not exceed 5-O kN/m.

column of a multi-storeved building ( with mixedoccupancy ) is shown in Fig. I. Calculate the

A-l.1 Applying reduction coefficients in accor-dance with 3.2.1, total reduced floor loads on the

reduced imposed load for the design of column column at different levels is indicated along withmembers at different floor levels as given in 3.2.1. Fig. 1.

17


19/20


20/20

Bureau of Indian Standards

BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goods andattending to connected matters in the country.

Copyright

BIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations.Enquiries relating to copyright be addressed to the Director (Publication), BIS.

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 reaffirmed when 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 latest amendments or edition by referring to the latest issueof BIS Handbook and Standards Monthly Additions.

Amendments Issued Since Publication

Amend No. Date of Issue Text Affected

BUREAU OF INDIAN STANDARDS

Headquarters:Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002Telephones: 323 01 31,323 33 75,323 94 02

Regional Offices:

Telegrams: Manaksanstha(Common to all offices)

Telephone

Cen t r a l : Manak Bhavan, 9 Bahadur Shah Zafar MargNEW DELHI 110002

Eas t e rn :

Northern :

l/14 C.I.T. Scheme VII M, V.I.P. Road, ManiktolaCALCUTTA 700054

SC0 335-336, Sector 34-A, CHANDIGARH 160022

Southern : C.I.T. Campus, IV Cross Road, CHENNAI 600113

Western :

Branches :

Manakalaya, E9 MIDC, Marol, Andheri (East)MUMBAI 400093

AHMADABAD. BANGALORE. BHOPAL. BHUBANESHWAR.COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI.HYDERABAD. JAIPUR. KANPUR. LUCKNOW. NAGPUR.PATNA. PUNE. THIRUVANANTHAPURAhl.

32376 17,3233841

337 84 99,337 85 61337 86 26,337 9120

{60 38 4360 20 2.5

1235 02 16,235 04 422351519,2352315

{832 92 95,832 78 58832 78 91,832 78 92

Irintedat Printograpb, New Delhi, Ph : 5726837

Documents

Is 875 Part 2 1987 Code of Practice for Design Loads (Othe