Abstract: With the largescale development of construction, the width and depth of the foundation of highrise buildingsismore and more large,and the boundary conditions of the foundation become more and more complex. Besides,in order to satisfy the requirements of a variety of functional use, there increasingly emerged with manyconditions such as the podium designed as a whole with the main building, or the adjacent buildings approaching so close to the main building edges, when determining the characteristic values of the bearing capacity of the foundation, the specificationdoesn'tdefine how to reasonably consider the influence of the ground overload on the depth correction. For a variety of complex foundational boundary conditions, the adjacent overloading situations above the foundation vary differently, based on the theory of limit equilibrium of soil , this paper discussed how the depth correctionof subgrade bearing capacity is considered and how to judge the depth and range of the overload correctly and reasonably.

Key words: mainand attached building, subgrade bearing capacity, depthmodification, plan surcharge, characteristicvalue of bearing capacity