Analysis on Forced Deformation of Double Row Piles Considering Pile-pile Interaction in Layered Foundation

Based on the force and deformation characteristics of the double-row pile retaining structure in the layered foundation, the front and rear row piles were regarded as elastic foundation beams inserted vertically into the layered foundation, and the interaction between the front and rear row piles and the layered soil is simulated by a series of horizontal springs with different stiffnesses. Taking the contact surface of each soil layer as the interface, the front and rear row pile support structures are divided into several parts. The active earth pressure acting on the rear row piles is calculated by Rankine earth pressure theory, and the passive earth pressure below the bottom surface of pit foundation of the front row pile is calculated by elastic resistance method, taking into account the linear variation of resistance coefficient of foundation along the depth. Based on the theory of Euler-Bernoulli double-layer foundation beam, the pile-pile and pile-soil interaction are considered to obtain the differential equations and the power series solutions of double-row pile support structure in the layered foundation. Then, according to the continuous conditions of internal force and displacement and the boundary conditions of pile top and bottom, the horizontal displacement, rotation, shear force and the bending moment of any depth of pile can be obtained. Finally, through one engineering example, the calculation results of this method are compared with the reported results, which verifies the feasibility of the proposed method. © 2020, Editorial Department of Journal of Hunan University. All right reserved.