桩锚结构变形协调方法的改进研究

桩锚结构变形协调条件是桩锚结构设计中内力计算的关键点。现行桩锚结构变形协调条件是在锚索施加预应力后桩身向坡内变形十分微小而忽略不计的条件下推导得到的，只适用于锚索预应力微小或为0的情况。但在许多工程实例中，锚索的预应力较大，导致的桩身变形不能被忽略。因此，现行的变形协调条件假设与桩锚结构的实际工作状态不一致。利用结构力学理论，在研究桩锚结构体系的两阶段变形过程的基础上，对变形协调方程从2个方面改进，其一是改变原有方法中抗滑桩滑面处位移和转角的计算方法；其二是改变第j排锚索对桩身 点处位移贡献的计算形式。算例分析表明，改进桩锚结构变形协调条件，可以更好地为工程设计服务。

Improvement of compatible distortion method for structure of pile-anchor

Compatible distortion method of structure of pile-anchor is a key point in internal force computing of structure of pile-anchor. The present method is derived from a hypothesis that the distortion of the pile is very small, or even can be ignored. Thus the method can be used only when the prestressed force of cable is very small or null. But in a lot of engineering case, the prestressed force of cable is significant and the distortion of pile can’t be ignored. So, the hypothesis of present method is not in accordance with the working condition of the structure of pile-anchor. Based on studying on the two steps of distortion process, the present method is improved with structural mechanics theory in two aspects. Firstly, the calculating method of the distortion and rotation in the slipping surface is modified. Secondly, the formula which is used to count the distortion made by the anchor on the j row to the i point on the pile is improved. An example is given to prove that the improved method is more useful to the engineering design.