关键词: 深基坑, 排桩支护结构, 变形协调, 空间效应

Abstract: This paper aims to propose an analytical method for complex supporting problems of deep foundation pit using elastic resistance method and structure mechanical method, with considerations of compatibility of deformation and spatial effects for retaining pile, crown beam, and braces. Comparisons between calculation results and field data indicate the effectiveness of the proposed method, and further parametric study investigates the spatial and size effects of crown beam and braces on the deformation of retaining piles. Results show that the deformation of retaining structure is nonlinearly related to the dimensions and spatial distributions of crown beam and braces. For retaining structure without waist retaining, the maximum displacement of the crown beam increases exponentially with the brace spacing, and the maximum displacement of retaining pile occurs at a depth of about 1/3 of the pile length which gradually shifts to the pile top with the increase of brace spacing. The effect of increasing bracing stiffness to prevent the deformation of retaining structure is limited when the bracing stiffness is larger than a certain limit, and the displacement of crown beam in the side span is shown greater than that in the middle span. Increasing the sectional width of crown beam by certain significance could restrain the maximum displacement of the crown beam.

Key words: deep foundation pit, row-pile retaining structure, compatibility of deformation, spatial effects