This section presents some general statements regarding the implementation of Indian Standard code of practice (IS:800-1984) for structural steel design in STAAD.Pro. The design philosophy and procedural logistics for member selection and code checking are based upon the principles of allowable stress design.

Two major failure modes are recognized:

1. failure by overstressing
2. failure by stability considerations.

The flowing sections describe the salient features of the allowable stresses being calculated and the stability criteria being used. Members are proportioned to resist the design loads without exceeding the allowable stresses and the most economic section is selected on the basis of least weight criteria. The code checking part of the program checks stability and strength requirements and reports the critical loading condition and the governing code criteria.

It is generally assumed that the engineer will take care of the detailing requirements like provision of stiffeners and check the local effects such as flange buckling and web crippling.

There are no special provisions specifically for double-I sections in IS 800-1984. Therefore, these sections are designed in STAAD.Pro as other general sections using the section property values of the double-I section specified.