Abstract
The purpose of present study is to propose the approximate technique taking deflection of foundation girders and pile-soil into consideration for structural analysis. Separation of the upper structure from the pile-soil structure is the practical method in case of structural frames with foundation girders constructed from reinforced concrete of high stiff ness, but it isn't a general method in case of foundation girders of finite rigidity. In the pres ent analysis, two approximations are applied, and those enable to separate the analysis of the upper structure from that of the pile-soil structure. This is proposed as a new approximation method of rotation-rigidity.
