大型洞室群稳定性与优化的进化有限元方法研究

随着地下洞室群规模的日益扩大，迫切需要一种更新的全局优化方法以提高效率、优化结构在保证工程稳定性的同时能最大限度地减小工程造价。遗传算法的最新发现使得大型洞室群稳定性的最优建模和获得全局最优解成为可能。针对某地下洞室群工程，提出了进化有有限元方法，对工程软岩置换方案进行了优化。将有限元与遗传进化算法相结合，由遗传算法产生一组初始可行方案，以洞室开挖引起的破损区体积大小与参考值的增量比为评价指标，经过遗传变异操作，产生一组新的软岩置换方案，对每种方案进行应力分析，确定破损区大小，最终得到损坏区体积最小的方案即为最优软岩置换方案。这种方法可以优化得到全局最优解，并且搜索速度较快，较目前其它方法更易于在微机上实现。运用于实例中，得出了合理的置换方案，并提出了施工的合理化建议。

The research of evolutionary finite element method of the stability and optimization at large cavern group

With ever enlarging scale of the underground cavern group,a new way of global optimization is badly in need,which would lead to higher efficiency,better structure and minimum cost with assured stability at the same time.Recent developments in Genetic Algorithms(GAs)make it possible to optimally model and obtain global optimal solutions in the stability of large cavern group.A new method of replacement optimization of soft rock mass was proposed and applied to a large cavern group.The method combines FEM and Genetic Algorithms (GAs).At the beginning,a set of initial tentative replacement schemes was randomly generated.The volume of damage zone was calculated for each tentative replacement scheme to evaluate applicability of the scheme.A group of new schemes was then generated by operation of GAs.The process continued until the best solution was found.Compared with the other existing methods,this new method has a faster speed,is easier to be carried out on personal computer,and can obtain optimum solution in global space.An example of application was given.The feasible scheme was obtained and the reasonable suggestions were also given for the safe construction.