【作者】 林永亮；

【导师】 范文；

【作者基本信息】 长安大学 ， 地质工程， 2004， 硕士

【摘要】 在土力学中，计算土体作用在结构上的力是一个古老的课题，经典的Coulomb(1776)和Rankinc(1857)土压力理论，因其计算简便和力学概念明确而一直为工程设计所采用。但经典土压力理论都把挡土结构视为刚性体，土体是理想刚塑性，服从Mohr-Coulomb强度准则。显而易见，这些计算方法都有一个共同的理论基础—Mohr-Couiomb强度理论，均未考虑中间主应力效应的影响。但俞茂宏的统一强度理论恰恰能弥补此不足之处，该强度理论具有一个统一的力学模型、统一的理论假设以及统一的数学表达式能灵活地适用于从金属到岩土类的各类材料。根据统一强度理论能够得到一系列的解，经典理论为其特例。由于统一强度理论在土压力中的应用还很少，基于此，本论文对土压力问题进行了一些探索性的研究。 将统一强度理论的抗剪强度统一表达式引入到平面应变问题的极限平衡理论中，推导了考虑变位模式的主动土压力公式，推广了现有的计算公式；根据普朗特尔理论，从地基强度角度出发，推导了具有对数螺线滑动面的统一土压力公式；在土压力的塑性极限分析中，详细推导了有限范围内土压力的上限解，现有的计算公式为其特例：在分析各向异性损伤对土压力的影响时，引入了统一弹塑性损伤模型，推导出了考虑各向异性损伤时的统一土压力公式，可以灵活地适用于岩土材料。 南于桩排式支护结构被广泛的应用，在研究基坑支护中的土压力时，以其为例，根据桩后土体的三维破坏模式，详细推导出了考虑中间主应力效应的主动土压力公式的上限解。更多还原

【Abstract】 The determination of forces on structures which are connected to earth mass is of paramount importance in applied Geotechnical Engineering. Classical soil pressure theories enunciated by Coulomb and Rankine have been widely used for the soil pressure analysis and the design of the retaining structures within the validity of the assumptions of these theories. The solutions based on the Mohr-Coulomb theory are not considering influence of the intermediate principal stress, but the unified strength theory by Yu-Maohong can solve the problem well. The unified strength theory is a new kind of strength theory to have unified mechanical model and theoretical assumption, and a simple, linear and unified mathematical expression adapted for many kinds of materials. The study on soil pressure based on the unified strength theory is rather little, so a series of new achievements in this aspect are acquired.The shear strength unified formula of the unified strength theory under the condition of plane strain is introduced into limit equilibrium, and then the formula of active earth pressure is deduced for the wall movement modes. The tradition formula is popularized by the unified strength theory. According to the theory of Prandle, the unified earth pressure formula of retaining wall with logistic spiral sliding surface is derived. The calculation of normal earth pressure is based on semi-infinite assumption , so the unified formula of finite soil pressure is obtained through the limit analysis of soil mass. In the earth pressure on retaining wall influenced by anisotropic damage, the unified equations are obtained and they are suitable for geomaterials.Pile row structure is one of the most common retaining structures for deep excavation. In the last, so the active earth pressure considering the intermediate principal stress is deduced through the three-dimensional failure of soil mass.更多还原