中文摘要：

由于支护空间受到限制等原因,一类双排桩支护型式设计为前后排桩之间没有土体,形成只有后排桩挡土的空间门架式结构,国内外目前尚无此类双排桩支护结构内力计算方法。针对这类双排桩,把前后排桩看作是竖放的弹性地基梁,用土弹簧模拟基坑开挖面以下的土抗力,根据弹性地基梁的挠曲微分方程对双排桩进行分段,建立各自的内力方程。利用幂级数法结合桩端边界条件求出开挖面以下桩身的内力及变形,然后由连系梁中间截面的变形协调条件,建立力法方程,求解出连系梁中间截面的内力,进而求出前后排桩各截面的内力。结合工程实例对这一类型式的双排桩支护结构进行计算并与实测值作对比分析,提出对这一类双排桩支护结构设计有参考价值的建议。

英文摘要：

For the reason that the retaining space suffers from the restraint, a type of retaining structure with double-row piles is designed as the structure without soil solum between the pre-row pile and post-row pile, to form the soil-retaining spatial door-frame structure in the post-row pile. At present, there is no calculation method for internal force of such kind of retaining structure with double-row piles. For this type of double-row piles, the pre-row pile and the post-row pile are both considered as elastic foundation beam placing upright. The soil spring is employed to simulate the soil resistance under excavation surface. The sections of double-row pile are divided on the basis of differential equations of elastic foundation beam deflection to establish internal force equations of sections. The power series method is used to determine the internal force and deformation of the pile body below the excavation surface with the boundary condition of pile tip. Under the deformation compatibility condition of middle section of coupling beam, a equation of force method is established to get the internal force of middle section of coupling beam; and then the internal forces of different sections of the pre-row pile and the post-row pile are obtained. Finally, combining with the engineering examples, this type of retaining structure with double-row piles is calculated and the calculation results are compared with the measured statistics. Some valuable suggestions are put forward for design of this type of retaining structure with double-row piles.