【作者】 韩丽娟；

【导师】 栾茂田；

【作者基本信息】 大连理工大学 ， 岩土工程， 2004， 硕士

【摘要】 桩土相互作用问题是近年来桩基工程中的研究热点与难点课题。通常各类建筑工程中的桩基础主要是主动受荷桩，即上部结构的荷载通过承台传递给下部的桩基础，由桩土间的相互作用来分担上部结构荷载。然而，在桩基工程中仍有许多情况是桩基承受被动荷载，即桩周土体竖向或水平运动行为引入的荷载，如粘性土的固结、膨胀土的膨胀或沉降、隧道的开挖、洞穴扩展及边坡滑动等对桩基础所产生的荷载。其表现为在桩基中引起附加作用力和附加应力，这将对桩基的承载机制与变形特性产生重要的影响。 本文针对大面积地面堆载条件下的邻近桩基进行分析，假定桩为简单的弹性地基梁，而桩周土作为弹塑性变形体。基于桩与土的变形协调条件，确定桩侧土压力的表达式，在此基础上建立桩身挠曲控制微分方程，联合采用非线性p-y曲线与有限差分法进行求解，并编制了相应的计算程序。通过算例分析，验证了所建议分析方法的合理性和实用性。同时，对影响被动桩桩—土体系变形的各种复杂因素进行了系统的比较分析，结果表明：桩的水平位移与桩的抗弯刚度以及桩土间水平作用力密切相关，相应的桩周土的位移取决于土体强度、桩土间相互作用力以及自由场地的土体水平运动等。通过分析还得出了其它一些有意义的结论。更多还原

【Abstract】 The issue of pile-soil interaction is the research hotspot and difficult subject in pile foundation engineering for recently several years. The majority of piles are designed to support "active" loadings, that is to say, loads from upper structure are directly transferred to the pile foundation by the cap. However, there are many cases in which the piles have to withstand "passive" loading, i.e. loads in the piles are often induced by the movement of soils past the piles vertically and/or horizontally. Examples include consolidation of clay; swelling or shrinking of an expansive clay; tunneling; excavation; cavity development; slope movement. These externally-imposed soil movements will lead to additional forces and stresses into pile foundations. Therefore, it is very important to reasonably assess these forces and the corresponding effects on the bearing and deformation performance of pile foundation.This paper analyzes the pile-soil interaction adjacent to superficial surcharge, the pile is modeled simple elastic foundation beam, soil to be elastic-plastic deformation body. Based on the compatibility condition of deformation of piles and surrounding soils, the expression formulation of lateral earth pressure on piles is presented. And then the partial differential equation for governing deflection of pile is established and is numerically solved by combining non-linear p-y relationship curve of pile and finite difference procedure. The author encodes the corresponding program. Through an example analysis, the reasonability and applicability of the proposed method are verified. Therefore this simplified method can be useful in evaluating the interaction behavior of pile and soils under passive state. Moreover, the author studies the complicated factors that affect the deformation of pile-soil system. The result indicates that the lateral displacement of the pile can be related to the pile bending stiffness and horizontal pile-soil interaction stresses, the lateral displacement of the corresponding soil is related to the soil stiffness, the pile-soil interaction stresses, and the free-field horizontal soil movements, and so on. According to the comprehensive analyses, the author draws some significant conclusions.更多还原