A method for analyzing anti-overturning stability of global retaining structures for deep slender foundation pits near bank slopes

The retaining structures for deep slender foundation pits near bank slopes are likely to overturn globally. The overturning failure mode is studied through indoor model tests and finite element numerical simulation, and a new method for analyzing the factor of safety of anti-overturning of retaining structures in sandy soils is suggested. The spatial effects of a retaining structure for a deep slender foundation pit as well as the influences of the earth pressures from the limited soil masses both inside and outside the pit are taken into account in the calculation of the factor of safety. From the calculated results of some exemples, it is found that the factor of safety of anti-overturning stability increases with the unit weight and the angle of internal friction of the soil. The further the bank slope is away from the retaining structures, the smaller the slope angle and the shallower the slope, the larger the factor of safety of the structures is. The larger the value of the surcharge loading on the side away from the bank slope is, the unsafer the structures are. However, when the distance between the structures and the bank and the slope depth reach respectively their certain values, the factor safety will be a constant value.