圆形地连墙环向刚度非线性及自锁效应的研究

Research on the Hoop Rigidity Non-Linear and Self-locking Effect of Circular Diaphragm Wall

圆形支护形式因其结构稳定、变形较小,具有拱效应等特点,使得混凝土能充分发挥其抗压能力,得以广泛应用于盾构施工工作井中。通过考虑圆形地连墙槽段间接缝泥皮的压缩变形,进而提出环向刚度折减系数的非线性变化计算方法。结果表明:地连墙环向刚度随位移增加而增加,从而发现圆形支护在变形中具有较好的自锁效应,说明其具有较好的安全性,与通常按圆形地连墙环向刚度等值折减的计算方法相比更安全且符合实际。用于珠三角水资源配置工程中开挖最深的LG03#圆形竖井进行支护变形内力分析,与实测数据进行比较,发现考虑环向刚度非线性的技术方法更符合实际,可为圆形地连墙提供一种新的计算方法。

The circular support forms have the characteristics of stable structure,small deformation,and arching effect,so that the concrete can give full play to its compressive capacity and this kind of support can be widely used in shield construction work wells.A calculation method for the non-linear change of the hoop rigidity reduction coefficient is proposed by considering the compression deformation of the mud in the indirect joint of the circular ground wall groove segment.The calculation results show that the circumferential stiffness increases with the increase of displacement and it is found that the circular support has a better self-locking effect in deformation,which shows that the circular support has better safety.It is also safer and more practical than the usual calculation method of equivalent reduction of the hoop rigidity of the circular ground wall.This method is used in the deepest excavated circular shaft named LG03#shaft in Pearl River Delta Water Resources Allocation Project to analyze the internal force of the support deformation.Compared with the actual measurement data,it shows that the technical method considering the non-linearity of the hoop rigidity is more realistic and can provide a new calculation method for this structure.