A load combination results when more than one load type acts on the structure. Building codes usually specify a variety of load combinations together with load factors (weightings) for each load type in order to ensure the safety of the structure under different maximum expected loading scenarios.

## Which load combination is correct?

What are the load combinations of ASD and LRFD?

ASD

LRFD-LC1 1.4(D+F)
LRFD-LC2a 1.2(D + F + T) + 1.6(L + H) + 0.5Lr
LRFD-LC2b 1.2(D + F + T) + 1.6(L + H) + 0.5S
LRFD-LC2c 1.2(D + F + T) + 1.6(L + H) + 0.5R
LRFD-LC2i 1.2(D + F + T) + 1.6(L + H) + 0.2Di + 0.5S

What is the most common load combination?

These are also known as ultimate load combinations:

• 1.4D.
• 1.2D + 1.6L + 0.5(Lr or S or R)
• 1.2D + 1.6(Lr or S or R) + (L or 0.5W)
• 1.2D + 1.0W + L+0.5(Lr or S or R)
• 1.2D + 1.0E + L +0.2S.
• 0.9D + 1.0W.
• 0.9D + 1.0E.

### Is 1893 a load combination?

For IS 1893:2016, the maximum load combination factor is 1.5 and for NBC 105:1994 the maximum load combination factor is 1.3.

It focuses on the requirements for general structural design, as well as providing a means for determining loads (dead, live, soil, flood, snow, rain, ice, earthquake, wind) and their combinations. Allowable Strength Design (ASD) involves eight basic load combination equations.

Today, the Bureau of Indian Standards (BIS) has the following seismic codes: IS 1893 (Part I), 2002, Indian Standard Criteria for Earthquake Resistant Design of Structures (5th Revision) IS 4326, 1993, Indian Standard Code of Practice for Earthquake Resistant Design and Construction of Buildings (2nd Revision) IS 13827 …

#### How many load combinations are there in LRFD?

seven
Load and Resistance Factor Design (LRFD) involves seven basic load combination equations.