基于承载复合体的隧道位移反分析研究

初期支护与松动圈围岩的协调作用表现出很大的不确定性,其主要影响因素包括:初期支护施工本身导致初期支护的不均匀性,实际围岩的不确定性对初期支护的影响,围岩释放应力的不均匀性导致的初期支护内力分布的不确定性。文章把初期支护的支护和围岩自身自稳能力看成是双介质的承载复合体,采用最小二乘法建立目标函数,结合单纯形算法,进行初期支护与扰动区的联合位移反分析,充分揭示了初期支护与围岩松动圈之间的协调作用;结合实际工程与不考虑初期支护不确定性因素影响的反演分析进行对比,结果显示本文方法反演精度提高39％,预测精度提高了13％。

BEARING-COMPLEX MODEL FOR BACK-ANALYSIS OF TUNNEL DISPLACEMENT

The coordinating function between the primary supporting and the broken rock has the prominent character of uncertainty.The main effecting factors are as follows: the non-uniformity of primary supporting coming from the construction,the effect coming from the uncertainty of actual surrounding rock,the uncertainty of internal force distribution in primary supporting coming from the non-uniformity of releasing stress on surrounding rock.The retaining of primary supporting and the self-stabilization capability of rock are regarded as a dual-media(i.e.,the bearing complex model).The displacement objective function is constructed by the least square formulas.Combining with the optimization method of simplex,the model with the "bearing complex" is applied to back-analysis of road tunnel.The results reveal the coordinating function between the primary supporting and the broken rock zone.In contrasts to the inversion result without considering the uncertainty of the primary supporting,the accuracy of inversion is improved 39% and the accuracy of prediction is improved 13%.Thus,The proposed method and the results can be used as reference to the construction and design of road tunnel with similar conditions.