Abstract: Based on the introduction of surrounding pile-soil coupling anti-slide structure, a numerical analysis model of this new structure is set up. By analyzing the characteristics of stress and strain, soil-arching effect about surrounding pile-soil and coupling effect of the entire structure are discussed. Furthermore, by the model test, soil pressure distribution before and after surrounding pile and sorrounding pile bending moment distribution are tested. The mechanism of surrounding pile-soil coupling effect is proved. Finally, according to relative horizontal displacement of pile-soil coupling, the influences of the distance of behind pile, different depths of plan and different parameters of soil strength and varying effect of soil arching effect are discussed. Then, the main conclusions are drawn as follows: (1) There are four arch forms among the couple structure, such as expanding arch close to the surrounding piles, hyperbola arch between surroundind piles, hyperbola arch protruding outside between surrounding piles and hyperbola arch protruding inside between surroundind piles. (2) Anchoring to a definite depth, it can form a coupling anti-slide structure in the condition of about 4 times diameter space between surrounding piles, horizontal section using hexagon and the top using a ring girder. It can provide a guide to use the new anti-slide structure.

Key words: surrounding pile, anti-slide structure, soil arching effect, coupling effect, numerical analysis, model test