Study of calculation theory for retaining structure with prestressed double-row piles and its engineering application

Based on the previous study and comparative analysis of two current calculating models, a new calculating model of prestressed double-row piles is presented, considering the double-row piles and soil between piles as dimensional equivalent truss and pile end as elastic restraint and meanwhile adopting the method of exerting vertical prestress on back-row pile to balance pile-side soil pressure and improve the mechanical performance of front-row and back-row piles. The calculating models of dimensional equivalent truss and the method of exerting vertical prestress on back-row pile are essentially verified by comparative analysis of three calculating models and FEM programme. Combining with engineering example, the key factors influencing prestressed double-row piles are analyzed. Both the calculating analysis and the engineering application show that a satisfactory result can be obtained with spatial equivalent truss and the method of exerting vertical prestress on back-row pile.