圆拱效应等效支撑的计算方法

Calculation method of equivalent support for round-arch effect

圆形基坑受力具有明显的空间效应,为了将空间效应量化以便合理的应用于实际工程中,沿用现行规范推行的“平面竖向弹性地基梁法”的理念,利用弹性力学中圆筒受均布荷载的解析解,推出拱效应等效刚度系数,系数值即为目前工程中常用到的支护设计软件在设置虚拟支撑时所需要的重要参数,从而实现圆拱效应的量化。并将此方法同三维连续介质有限元法对某“圆筒状”竖井从地连墙水平位移变化曲线以及基坑稳定性两方面进行对比分析,发现两者计算结果差距较小。

Round foundation pit force has obvious spatial effect. In order to quantify space effect to reasonable application in practical engineering, using the current specification of "plane vertical elastic foundation beam" concept, and using elastic cylinder by uniform load, the arch effect equivalent stiffness coefficient is deduced, with is the current engineering support design software in the virtual support required important parameters, so as to realize the quantification of round arch effect. This method and the three-dimensional continuous medium finite element method are compared and analyzed on the horizontal displacement change curve of a "cylindrical" shaft from the ground wall and the stability of the foundation pit, and the difference between the calculation results of the two is small.