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REF:- Reinforced Concrete Design Manual,2008,CSI,using different codes ACI-318-2008, Design Load Combinations The design load combinations are the various combinations of the load cases for which the structure needs to be designed. For ACI 318-08, if a structure is subjected to dead load (D), live load (L), pattern live load (PL), snow (S), wind (W), and earthquake (E) loads, and considering that wind and earthquake forces are reversible, the following load combinations may need to be considered(ACI 9.2.1): ********************************************************* ***************** 1.4D (ACI 9.2.1) ********************************************************* ***************** 1.2D + 1.6L (ACI 9.2.1) ********************************************************* ***************** 1.2D + 1.6 (0.75 PL) (ACI 13.7.6.3) ********************************************************* ****************************

Load Combinations According to BS, ACI & Indian Codes

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Load Combinations according to BS, ACI & Indian codes

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Page 1: Load Combinations According to BS, ACI & Indian Codes

REF:- Reinforced Concrete Design Manual,2008,CSI,using different

codes

ACI-318-2008, Design Load Combinations

The design load combinations are the various combinations of the load cases

for which the structure needs to be designed. For ACI 318-08, if a structure is

subjected to dead load (D), live load (L), pattern live load (PL), snow (S), wind

(W), and earthquake (E) loads, and considering that wind and earthquake

forces are reversible, the following load combinations may need to be

considered(ACI 9.2.1):

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1.4D (ACI 9.2.1)

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1.2D + 1.6L (ACI 9.2.1)

**************************************************************************

1.2D + 1.6 (0.75 PL) (ACI 13.7.6.3)

*************************************************************************************

0.9D ± 1.6W,,,,,,,,,,,,,,,,,if W is based on service-level wind loads

0.9D + 1.0W

1.2D + 1.0L ± 1.0W

1.2D+1.0L±1.6W,,,if W is based on service-level wind loads (ACI 9.2.1)

*************************************************************************************

0.9D ± 1.0E

0.9D ± 1.4E ,,, ,,,if E is based on service-level forces

1.2D + 1.0L ± 1.0E (ACI 9.2.1)

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1.2D + 1.6L + 0.5S

1.2D + 1.0L + 1.6S

1.2D + 1.6S ± 0.8W

1.2D + 1.0L + 0.5S ± 1.6W

1.2D + 1.0L + 0.2S ± 1.0E (ACI 9.2.1)

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The IBC 2006 basic load combinations (Section 1605.2.1) are the same.

Page 2: Load Combinations According to BS, ACI & Indian Codes

The structural effects of load T shall be considered in combination with other

loads. The load factor on T shall not have a value less than 1.0 (ASCE-SEI-7-

10-2010) &( ACI-318M-2011, 9.2.3-Self-straining effect ).

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1.2D + 1.2 T + 1.6L ,,, Design of Concrete Structures, Nilson, Darwin &

Dolan,2010,14th ed, Table 1.2 page 18 & Reinforced Concrete-a

Fundamental approach-1,E.G.Nawy-5th ed,2005, page 82

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BS-8110-1997, Design Load Combinations

The design load combinations are the various combinations of the load cases

for which the structure needs to be designed. The design load combinations

are obtained by multiplying the characteristic loads by appropriate partial

factors of safety, γf (BS 2.4.1.3). For BS 8110-1997, if a structure is subjected

to dead load (D), live load (L), pattern live load (PL), snow (S), and wind (W)

loads, and considering that wind forces are reversible, the following load

combinations may need to be considered (BS 2.4.3).

**********************************************************************

1.4D

1.4D + 1.6L (BS 2.4.3)

*********************************************************************

1.4D + 1.6(0.75PL) (BS 2.4.3)

*********************************************************************

1.0D ± 1.4W

1.4D ± 1.4W

1.2D + 1.2L ± 1.2W (BS 2.4.3)

*********************************************************************

1.4D + 1.6L + 1.6S

1.2D + 1.2S ± 1.2W

1.2D + 1.2L + 1.2S ± 1.2W (BS 2.4.3)

Page 3: Load Combinations According to BS, ACI & Indian Codes

Indian Code- Design Load Combinations

IS-875-5-1987(2003),General Combinations

a) DL

b) DL+LL

c) DL+ WL

d) DL+EL

e) DL+TL

f) DL+LL+ WL

g) DL+LL+EL

h) DL+ LL+ TL

i) DL+ WL+ TL

k) DL+EL+ TL

m) DL+LL+WL+TL

n) DL+LL+EL+TL

(( DL = dead load, LL = imposed load, WL = wind load, EL = earthquake load,

TL = temperature load ).

IS 1893-2002-Pt.1- 6.3.1.1

Load factors for plastic design of steel structures

In the plastic design of steel structures, the following load combinations shall

be accounted for:

1) 1.7(DL.+LL )

2) 1.7(DL*EL)

3) 1.3(DL+LL+EL)

IS 1893-2002-Pt.1- 6.3.1.1

Partial safety factors for limit state designof reinforced concrete and

prestressed concrete structures

In the limit state design of reinforced and prestressed concrete structures, the

following load combinations shall be accounted for:

1) 1.5( DL+LL)

Page 4: Load Combinations According to BS, ACI & Indian Codes

2) 1.2( DL+LL+EL)

3) 1.5( DL+EL)

4) 0.9DL* 1.5EL

****************************************************************************************

Other loads to be considered, but not listed in the Code (Table 18) include

0.75 (1.4 DL + 1.4 TL + 1.7 LL)

1.4 (DL + TL) Reinforced Concrete Design,Pillai & Menon,3.6.3 page 89

Serviceability limit states :

1.0 (DL + LL)

1.0 (DL + EL)

1.0 DL + 0.8 LL + 0.8 EL

Reinforced Concrete Design,Pillai & Menon,3.6.3 page 88

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