Abstract: Composite gravity retaining wall is one type of excavation support structure that in between gravity retaining wall and piled supporting structure. Since the complicated relationship of this internal structure of the retaining wall, there has not been an appropriate deformation estimation method other than the finite element method. Based on the elastic Winkler model, this paper proposes a twostep iterative calculation method considering its spatial effects. The first step of the calculation is a conventional method in accordance with the Winkler model, the second step is to superpose an additional moment generated by friction of interpolated reinforcement structure to the grid point on the Winkler beam, using the deformation curve obtained by the first step. Through an engineering example, the method is validated.  

Key words: Composite Gravity Dam, Deep Excavation Support, Spatial Effects, TwoStep Method