基于周边收敛的初始地应力场反分析

Inverse analysis on initial stress field based on peripheral displacement convergence

基于隧道开挖导致的周边收敛量测值,结合FLAC^(3D)正分析得出的一些位移基础量,通过分解、模拟自重应力场及边界构造应力场,建立周边收敛位移的线性方程组,并采用最小二乘法矛盾方程,然后反推出初始地应力场。将反演分析得出的初始地应力场的结果代入FLAC^(3D)进行数值模拟计算,正算该典型断面在开挖完成以后,下台阶收敛测线的最终净空收敛值,并将其与现场监控量测得到的实测数据进行对比分析。分析表明两者基本吻合,验证了反演分析的合理性。

Based on peripheral convergence measurement value caused by tunnel excavation and basic displace- ment proposed by FLAC3D, system of linear equations of peripheral displacement convergence was established in this paper by disassembled and simulated self- weight stress field. By virtue of least square method, the incon- sistent equation was solved, and the inital stress field was then datermined. Plugging the inverse analysis results into FLAC3D, the clearance convergence value in the bottom bench convergence survey line after the excavation of the typical sections is analyzed and the result was compared with the test data. The result show that the measured value basically agrees well with calculated value, which verifies the rationality of the inverse analysis.