基于二次正交试验优化的隧道围岩稳定可靠度方法

Reliability degree method for stability of surrounding rock of tunnels based on quadratic orthogonal experimental optimization

通过把二次回归正交组合试验设计和显著性检验结合起来,构建出了各类因素对结构特征值影响程度的判别方法。将该方法植入隧道围岩稳定响应面可靠性分析程序中,建立了具有识别基本因素重要性程度功能的状态函数优化方法,消除了序列响应面状态函数建立时不能判断基本因素对结构状态重要性程度的缺陷。利用MATAB搜索技术求解基于状态函数优化方法改进的响应面可靠度指标,解决了分析结果失真问题。上述两者的结合形成了具有较高效率的复杂地层隧道围岩稳定可靠度响应面分析技术。通过某工程实例研究,演示了该技术的运行过程和操作程序,并在效率、分析结论的准确性等方面进行了对比验证。

By integrating the quadratic regression analysis of orthogonal composite design and the statistical significance testing, a discriminant method to describe the effect degree of various factors on structural eigenvalue is established. By introducing such a method into the reliability analysis process of response surface for the stability of the surrounding rock of tunnels, an optimum approach for identifying the degree of importance with respect to basic ingredients for state function is developed, which can eliminate the drawback of being incapable of assessing the importance degree of basic ingredients on the structural state when establishing a series of response surfaces for the state funetion. A MATLAB-based search technology is utilized to solve the reliability index of the improved response surface by means of the optimum approach developed for the state function, which figures out the problem of result distortion. On the basis of the integration between both the above methods, a response surface analysis technique with relatively high computational efficiency is then proposed for the reliability evaluation of the surrounding rock of tunnels in complicated stratum. The proposed technique is illustrated by a certain practical example, in which the running process and operating procedure are demonstrated, and then several aspects related to this technique such as the computational efficiency and accuracy of the results are also verified, showing its validity and applicability.