基于位移反分析的浅埋偏压隧道有限元模拟分析

Finite Element Modeling of Shallow Buried Tunnel based on Displacement Back Analysis

为了更加准确地获取有限元模拟分析中围岩的力学参数,以广西隆林～百色高速公路某隧道为例,采用一种基于位移反分析的围岩力学参数选取方法。根据现场实测数据,采用BMP90位移反分析程序进行反分析得到等效弹性模量及侧压力系数,并在进行ANSYS有限元模拟计算时分别选用由反分析得到的等效弹性模量及侧压力系数和规范建议的取值,将最终计算结果与实测数据进行对比,结果发现基于位移反分析的计算结果与实测值较为接近,表明由反分析得到的围岩参数与工程实际更加吻合。研究内容能为隧道工程围岩力学参数的赋值选取提供一定的参考。

In order to more precisely to acquire the mechanics parameters of surrounding rock for finite element modeling, on the basis of a tunnel of Longlin-Baise Expressway in Guangxi Zhuang Autonomous Region, the method of acquiring the mechanics parameter of surrounding rock based on displacement analysis is applied. According to the field measurement raw data, the equivalent elastic modulus and lateral pressure coefficient are acquired by means of the displacement back analysis program, as BMP90. In the finite element modeling analysis, the equivalent elastic modulus and lateral pressure coefficient and parameters suggested from related standard are applied. The calculation results and the field measurement raw data are compared, and it shows that the calculated results based on the back analysis is more consistent with the field measurement raw data, and the surrounding rock parameters based on the displacement back analysis is more coincide with the real engineering. The study can provide certain reference for selection of mechanics parameters of surrounding rock.