预应力双排支护桩的计算理论研究及工程应用

在总结以往研究成果的基础上，对比分析现有的两种计算模型，提出新的计算模式，将双排桩及桩间土体视为空间等代桁架，并将前后排桩的底端视为弹性约束，同时采用对后排桩施加竖向预应力的方法，来平衡桩侧土压力和改善前后排桩的受力性能。利用有限元程序，通过对3种计算模型的对比分析，并与实测数据的对比，对所提出的计算模型和方法进行了必要的验证。结合工程实例，对影响预应力双排支护桩的关键因素进行了分析，计算分析和工程实例都表明：利用空间等代桁架模型和对后排桩施加竖向预应力的方法可以取得满意的结果。

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.