钢筋混凝土桩组合拱基坑支护结构的框架分析法

THE METHOD OF FRAME ANALYSIS OF BUILT-UP-ARCH STRUCTURE WITH RC PILES FOR SUPPORTING DEEP EXCAVATION

介绍了一种新的钢筋混凝土桩组合拱基坑支护结构的计算法———框架分析法。该法将钢筋混凝土桩组合拱支护结构进行简化 ,并假定在基坑开挖面以下一定范围内将桩固定 ,取出空间框架结构的计算模型。接着 ,利用无梁楼盖的等代框架法的思想 ,确定该框架中各层桩的等效抗弯刚度 ,用平面框架中的“D”值的思想计算桩顶侧移及桩身内力。最后 ,用三种分析方法进行计算 ,并结合工程实测资料对框架分析进行了验证和对比。

A new design method which can be applied to the built up arch structure with RC piles for deep excavation is presented,which is executed by the analysis of space frame.The structure is simplified and the piles are supposed to fix at certain place under the bottom of the deep excavation,then the model of space frame is obtained.Subsequently, the idea of transformed frame in the flat slab is used to calculate the piles'equivalent bending stiffness at each layer of the frame,so the displacement at the top of piles and the inner force of piles are acquired through the way of `D'value in the plane frame.In the end, a built up arch structure with RC piles in practice is recomputed by three methods,and the results are compared and verified with the spot measurement of a project.