Abstract: According to construction characteristics of deep foundation pile anchor retaining structure engineering, an incremental method to design and investigate the deep foundation pile anchor retaining structureis proposed.The nonlinear problem of pile displacement caused by excavation is solved approximately by the linear method, namely, the nonlinear curves are replaced by a series of segmented linear lines. By taking into account the influence of displacement of pile anchor retaining structure during excavation of the base pit, a displacement calculation formula for the soil pressure model based on the pile displacement has been derived. Then the pile displacement calculated in each step is revised by an iterative method, so as to avoid the error accumulation caused by incremental method. Combined with an engineering example, the above proposed method is programmed with MATLAB, and corresponding calculated results are compared directly with those predicted by both finite element simulation software PLAXIS and the conventional incremental method, the correctness and rationality of the method are verified.The proposed simplified method is closer to engineering practice and predictions by the method are more accurate than those by conventional incremental method.

Key words: deep excavation, pile anchor retaining, incremental iterative method, displacement earth pressure, pile displacement