具有随机参数的盾构管片弹性密封垫防水性能优化分析

Waterproofness Optimization for Elastic Rubber Gaskets in Shield Tunnels With Random Parameters

盾构管片接缝弹性密封垫断面的几何尺寸极易受生产工艺的影响而呈现出随机性,从而对盾构管片弹性密封垫的防水性能产生影响.该文选取密封垫的孔洞圆心坐标、孔径、断面宽度、断面高度等参数作为随机输入变量,运用ANSYS-PDS模块得出了各随机参数对密封垫防水性能的灵敏度数值,结果显示圆孔孔径对闭合压力及接触应力的影响较其他几何尺寸更大;圆孔垂向位置改变对闭合压力及接触应力的影响较横向位置更大.在此基础上,应用ANSYS优化设计模块,选取密封垫闭合压力和下表面平均接触应力作为状态变量,以在闭合压力不超过某一定值的条件下接触应力最大为目标函数,对密封垫进行几何参数优化分析,得出了某盾构隧道弹性密封垫优化断面,试验结果很好地验证了优化计算结果的可靠性.

Geometric parameters of elastic rubber gaskets in shield tunnels often present stochasticity influenced by the manufacturing process. Accordingly, the waterproof performance of elastic rubber gaskets will be affected. The coordinates of the hole center, the hole diameter, the section width and height were selected as the input random variables, and the sensitivity values with respect to these random parameters of the gasket＇ s waterproof performance were obtained by means of the ANSYS PDS module. The results show that the hole diameter has larger effect on the closure pressure and the contact stress than other geometric parameters. At the same time, the vertical position of the hole has greater influence than the horizontal one. On this basis, the closure pressure and the contact stress on the lower surface were selected as state variables, and the maximum contact stress was deemed as the objective function with the closure pressure not higher than a set value. The ANSYS design optimization module was used to conduct the parameter optimization for rubber gaskets, and give a new optimal gasket sec- tion geometry for one shield tunnel. The full-size test results verify the reliability of the optimal analysis.