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桩排式支护是目前国内各地普遍采用的一种深基坑支护形式， 但迄今对该支护形式中的主要受力构件——护壁桩的受力特点尚不十分明确， 护壁桩桩侧土压力的分布和取值以及桩身内力的分析方法也是工程应用中亟待解决的问题。针对这种情况， 主要开展了以下工作：（１） 结合工程实测资料， 对无锚撑和单锚桩排式支护结构中护壁桩的工作性能进行分析；（２） 根据由桩身钢筋应力推算出的桩身弯矩， 采用数值分析， 对桩侧土压力的分布和取值、护壁桩的变形形态、桩顶圈梁的约束作用以及锚杆拉力等进行分析， 结果表明， 现行设计方法不能完全反映工程的实际情况；（３） 应用土拱原理对桩侧土压力进行计算分析， 将间隔布桩的护壁桩桩侧土压力分为直接土压力和间接土压力两部分。应用小主应力拱的概念对直接土压力进行分析， 用水平面上的大主应力拱分析桩间土体产生的间接土压力， 并在分析护壁桩变形的基础上， 对基坑底面以下桩段上作用的土压力作了假设；（４） 提出了适于桩排式支护结构护壁桩内力分析的计算模型， 该计算模型可以综合考虑护壁桩的入土深度、桩身变形及桩顶圈梁的约束作用， 能较好地反映基坑支护中护壁桩的受力状态；（５） 通过控制桩间土体允许剥落范围， 提出了间隔布桩时护壁桩?
Pile-row support is a form of deep foundation pit support commonly used at home and abroad. However, the stress characteristics of the main force-supporting component in the form of support are not yet clear. The distribution and value of the lateral earth pressure and the analysis method of the internal force of the pile body are also problems to be solved urgently in the engineering application. In response to this situation, the following work was mainly carried out: (1) Based on actual engineering survey data, the performance of the retaining wall piles in the support structure without anchor and single anchor piles was analyzed; (2) According to the reinforcement of the piles The calculated bending moments of the piles were numerically analyzed. The distribution and value of the lateral earth pressures on the piles, the deformed shape of the retaining wall piles, the restraining effect of the pile top beam, and the anchor bolt tension were analyzed. The results showed that the current design The method can not fully reflect the actual situation of the project; (3) Apply the principle of soil arch to calculate and analyze the lateral earth pressure, and divide the lateral earth pressure of the retaining piles of interval piles into direct earth pressure and indirect earth pressure. The concept of small principal stress arch is used to analyze the direct earth pressure, and the major principal stress arches on the horizontal surface are used to analyze the indirect earth pressure generated between the soils of the piles. On the basis of the analysis of the deformation of the retaining wall piles, the foundation piles below the bottom of the foundation pit are analyzed. The hypothesis of the earth pressure acting on it was given; (4) A calculation model suitable for analysis of the internal force of retaining piles of pile retaining structures was proposed. This calculation model can comprehensively consider the depth of earth penetration of the retaining wall piles, the deformation of the piles, and the top beam of the piles. The restraint function can better reflect the stress state of the retaining wall piles in the foundation pit support; (5) By controlling the allowable spalling range of the soil between the piles, the retaining wall piles are proposed when the piles are spaced.