优化方法在弹性、横观各向同性以及弹塑性围岩变形观测反分析中的应用

本文采用四种最优化方法对地下工程围岩的岩体力学参数和初始地应力进行了优化位移反分析研究工作,编制了一套平面问题直接算法有限元程序,能解决弹性、横观各向同性及弹塑性等多种岩体互层的复杂围岩的优化位移反分析问题。结合两个工程实例进行了计算,结果是令人满意的。

APPLICATION OF OPTIMIZATION METHODS IN BACK ANALYSIS OF DEFORMATION MONITORING IN FLASTIC, TRANSVERSALLY ISOTROPIC AND ELASTOPLASTIC SURROUNDING ROCKS

This paper presents a research on the optimization methods of back analysis for rock mechanics parameters and initial ground stresses in the surrounding rocks of underground works. Four kinds of optimization methods are used, viz., the Simplex Acceleration Method, Complex Acceleration Method, New Powell Method and SUMT Method. An FEM programme, which can be used to solve plane problems by a direct algorithm and can automatically select the proper ones from the above-mentioned four methods, back analysis parameters and loading ways, is compiled. The programme can solve complicated optimization and back analysis problems of elastic, elastoplastic and orthogonally anisotropie surrounding rocks. It can also take tunnel supporting, multistep excavation and anchored jointed rock masses into consideration. Optimal back analyses of elastic, elastoplastic and transversally isotropic problems have been conducted in connection with two practical engineering projects with satisfactory results.