本文通过侧向卸荷应力路径试验；分析了天然固结地基土在基坑开挖侧向卸荷过程中墙后土体的变形规律；根据双曲线假定；并基于Duncan-Chang模型的计算参数推导其模量公式。公式能够较真实地反映侧向卸荷应力路径上土体变形规律；其计算参数可以通过常规三轴试验获得；因而易于在实际工程中推广应用。

提出了基于二维数学模型对溢洪道下游三维复杂运动流场进行模拟计算的一种新方法。通过对泄洪建筑物下游河道复杂流场水流运动及河床冲刷状况的分析，研究了自由面流消能区水流扩散方式、流动特征及相关水力要素的概化确定。根据主流下回流区和表层水股之间质量交换很小的特点，提出了把底部回流区域作为河道无实际过流部分即修正河流下边界条件，对溢洪道挑坎下游复杂流场进行二维数值模拟的方法。利用上述方法对某工程实例进行了数值模拟计算，计算结果与实际流场状况比较一致，较为真实的反映了自由面流区的流动。

本文基于拱梁法；通过把围护结构分析中常用的弹性抗力法与拱梁法有机地结合在一起；将拱梁法改造成为计算拱形围护结构的一种方法。这种计算方法能考虑拱脚桩变形的影响；能考虑有支撑的情况；在开挖线以下拱脚桩和拱壁假定由土弹簧约束；因此更合理地反映了拱形围护结构的实际情况。该方法计算所需准备的数据与弹性抗力法类似；所需输入数据少；计算速度快。通过工程实例计算表明；该方法的计算结果与实测结果吻合较好；可应用于工程实际。

本文针对悬臂式拱形围护结构的性状作了较系统地分析，考虑了插入深度、坑底土质、拱形状、拱壁刚度等因素对悬臂式拱形围护结构性状的影响。文中详细地分析了各因素对悬臂式拱形围护结构性状的影响规律，这些规律对悬臂式拱形围护结构的设计与应用具有重要的参考价值。

In this paper, the erosion-resisting coefficient is introduced to compute bed deformation in a crush bedrock river. In the case of crush bedrock, there is no proper control equation to describe bed stability, which leads to difficulty in calculation of the bed deformation through conventional method. The data from field survey are used to generalize the erosion-resisting capability where erosion-resisting coefficient describes. After the determination of longitudinal distribution expressed by polynomial regression and transversal distribution expressed by normal distribution function, the plane distribution of erosion-resisting coefficient in a crush bedrock river is obtained. With the computational results from horizontal 2-D flow mathematical model, erosion-resisting coefficient and controlling condition of local stability are employed to compute the values of bed deformation when riverbed is stable. The above method is applied in a case study, and the computational results of flow and bed deformations are in good agreement with physical model test data.