8.7.1 Stability analysis - NPTEL（8.7.1稳定性分析- NPTEL）.pdf

Design of Steel Structures Prof. S.R.Satish Kumar and Prof. A.R.Santha Kumar 8.7. Design procedure for foundation The design of any foundation consists of following two parts. 8.7.1 Stability analysis Stability analysis aims at removing the possibility of failure of foundation by tilting, overturning, uprooting and sliding due to load intensity imposed on soil by foundation being in excess of the ultimate capacity of the soil. The most important aspect of the foundation design is the necessary check for the stability of foundation under various loads imposed on it by the tower, which it supports. The foundation should remain stable under all the possible combinations of loading, to which it is likely to be subjected under the most stringent conditions. The stability of foundations should be checked for the following aspects. Check for bearing capacity The total downward load at the base of footing consists of compression per leg derived from the tower design, buoyant weight of concrete below ground level and weight of concrete above ground level. While calculating over weight of concrete for checking bearing capacity of soil, the position of water table should be considered at critical location i.e., which would give maximum over weight of concrete. In case of foundation with chimney battered along the slope of leg, the center line of chimney may not coincide with the