Types of Load:

All structures are subjected to such occasional gravitational loads which they are purported to bear as their basic function. For example, a railway bridge has to carry all the loads due to the various trains moving on it; highway bridges similarly have to carry vehicular traffic loads, and buildings have to carry the loads of the furniture, equipment and stores or of people inhabiting it. Such loads are called live loads. Further to that there might be stresses caused due to physical conditions, e.g. temperature, impact, fatigue, deformation, secondary stresses, erection stresses, stress-concentration, and many more.

It is often difficult to estimate the exact value of these loads, but from experience and experimental evidence an estimate can be made which are encoded in the codes of practice published by the various user organizations. A short list is given below:

(a)  Buildings: (IS: 875) (all parts) Structural Safety of Buildings: Loading Standards (Bureau of Indian Standards).

(b)  Earthquake resistant design of structure IS: 1893.

(c)  Blast-resistant design of structure IS: 4991.

(d) Storage Tanks (IS: 803 and IS: 804).

(e) Overhead travelling cranes and gantry cranes (IS: 3177 and IS : 4137).

(f) Overhead transmission line towers (IS: 802).

(g) Steel bridges (IS: 1915).

(h) Standard Specifications and Code of Practice for Road Bridges (Indian Roads Congress).

(i) Railway Bridge Loading Standards (Railway Design and Standard Organization).

A designer has to be guided through the relevant code of practice while designing a particular structure.