中文摘要：

在洞室黏弹性位移参数反分析中，对分层优化方法存在初始值选取困难、计算量大等问题进行了探讨，提出了基于最小二乘法的模式分层运算方法，改变参数求解机制，避免了由于初始值选取不当造成迭代不收敛的现象，加强了求解搜索的有效性，提高解的精度和稳定性，通过工程实例进行验证。数值计算结果表明，模式分层运算对洞室黏弹性多参数位移反分析计算的结果真实、可靠。

英文摘要：

There are some thorny problems such as uncertainty and instability solution produced by initial parameters when hierarchical optimization is applied to the viscoelastic cavern displacement in parameter inversion. A simple search method is used in the hierarchical optimization. The hierarchical pattern search is provided to solve these problems. A new method has some computing strategies based on least-square method, which can avoid iterative non-convergence when initial parameters are not optimally selected. Numerical results show that the hierarchical pattern search is nearly independent of the original value; and the method has high accuracy and validity for the viscoelastic cavern displacements of parameter inversion.