论文部分内容阅读
Greco提出的临界滑裂面搜寻的Monte Carlo搜索技术具有原理简单、适应性强、搜索性能好及容易编程实现等优点,目前该类方法已在边坡稳定的优化计算中有许多成功的应用。为能够在多块体上限法求解地基极限承载力的优化计算中应用Monte Carlo搜索技术,基于上限法相容速度场的要求及地基承载力问题的特点,对Monte Carlo搜索技术实现中的目标函数、几何约束条件、初始破坏面的产生以及收敛准则等重新进行了设置。由于Monte Carlo搜索技术随机性的特点,某一次的搜索优化往往存在陷入局部极值的危险,为解决这一不足,采取了随机设置多次初始破坏面分别进行搜索优化的办法,计算表明,优化效果很好。通过对实际问题的计算以及对比发现,Monte Carlo搜索技术在此处多块体上限法求解地基承载力问题中的优化应用是相当成功的。此外,由于此处的优化是以破坏面上的节点为对象的,因此,不但可以方便地考虑三角形块体的优化,而且也可以方便地考虑四边形块体的优化问题,其适用性更强。
The Monte Carlo search technique based on Greco’s critical slip surface has the advantages of simple principle, strong adaptability, good search performance and easy programming. At present, this kind of method has been successfully applied in the optimization of slope stability. In order to be able to apply Monte Carlo search technique in the optimal calculation of the ultimate bearing capacity of foundations by multi-body upper bound method, based on the requirements of upper bound compatible velocity field and the characteristics of bearing capacity of foundation, the objective function of Monte Carlo search technology , Geometric constraints, the initial failure surface generation and convergence criteria set again. Due to the random nature of Monte Carlo search technology, a certain search optimization often has the risk of falling into local extremum. To solve this problem, a random set of initial destructive planes are used to search optimization separately. The calculation shows that optimization good results. Through the calculation and comparison of practical problems, it is found that the Monte Carlo search technique has been quite successful in solving the optimal application of the foundation bearing capacity problem by using the multi-block upper bound method. In addition, since the optimization here is aimed at the nodes on the destruction surface, the optimization of the triangle block can be easily considered, and the optimization problem of the quadrilateral block can be easily considered, which is more applicable.