基于分区刚体-界面元方法的重力坝深层抗滑稳定分析

Stability Analysis of Deep Anti-sliding of Gravity Dam Based on Partitioned Rigid Body and Interface Element Method

将坝体及坝基系统分界为可变形滑动界面、刚性滑动块体和刚性基床三部分,建立了基于滑动界面应力变形协调、分区刚体静力平衡的分区刚体—界面元分析方法,其未知量仅包含分区刚体变形及滑动界面上的接触力。结合基于极限平衡方程的迭代解法,可快速准确求解重力坝深层抗滑稳定安全系数。对局部滑面未知情形,可通过搜索求解最危险滑动面。该方法可同时满足上限极限分析的运动许可条件和下限极限分析的应力许可条件,克服了现有规范分析方法通过假定来满足下限极限分析条件的缺点。最后通过某重力坝深层抗滑稳定分析算例验证了该方法的准确性。

The dam body and dam foundation system are divided into three parts:deformable sliding interface,rigid sliding block,and rigid foundation.A partitioned rigid body interface element analysis method was established based on the stress-deformation coordination of the sliding interface and the static equilibrium of partitioned rigid bodies.The unknown variables in this method only include the deformation of the partitioned rigid bodies and the contact forces on the sliding interface.Combined with an iterative solution based on the limit equilibrium equation,it can quickly and accurately solve the deep-seated anti-sliding stability safety factor of gravity dams.For unknown conditions of local sliding surfaces,the most critical sliding surface can be determined through a search.This method can simultaneously satisfy the kinematic admissibility condition of upper bound limit analysis and the stress admissibility condition of lower bound limit analysis,overcoming the limitations of existing code-based analysis methods that rely on assumptions to meet the conditions of lower bound limit analysis.The accuracy of this method is demonstrated through an example of deep-seated anti-sliding stability analysis of a gravity dam.