基于正交试验的隧道开挖面位移释放分析

针对目前关于位移释放系数的计算方法比较复杂的问题，基于二次回归正交组合试验设计方法，提出了位移释放系数公式构建方法，应用该方法对静水应力场中圆形隧道进行了一系列数值试验，建立了考虑多个因素的开挖面位移释放系数拟合公式，比较了各影响因素的敏感性大小.通过数值算例和工程实例分析，初步验证了该方法的有效性.研究结果表明：对于不同级别岩体，同一因素对开挖面位移释放系数的影响程度不一；地应力水平、岩体扰动、地质强度指标、H-B常数和泊松比对开挖面位移释放系数的影响较大，而岩石单轴抗压强度和变形模量影响较小.
The existing computational methods of displacement release coefficient are too complex. Based on quadratic regression orthogonal design，a construction method of displacement release coefficient formula was given，and a series of numerical experiments of a circular tunnel in hydrostatic stress field were carried out by the above method. The regression equation of displacement release coefficient was established，and the sensitivity of parameters was determined. Through analysis of numerical examples and a case history，the equation was proved to be reasonable and effective. The results indicate that for different levels of surrounding rock，the effect of the same factor on the displacement release coefficient of the tunnel face is different. Stress level，disturbance of rock mass，GSI，H-B material constant and Poisson's ratio have a great influence on the displacement release of tunnel face，while the intact rock strength and deformation modulus have little influence.