基于非线性有限元的马吉拱坝整体稳定分析

马吉水电站是怒江开发规划中的重要梯级电站。最大坝高为290m,属于超高拱坝,地质条件与岩体力学环境复杂,其应力和坝肩稳定对确保工程安全具有重要的意义。基于非线性有限元分析,采用变形加固理论,使用三维非线性有限元程序TFINE,对马吉拱坝进行三维弹塑性有限元数值模拟,对该拱坝在正常工况下的位移、坝体应力和拱端推力进行分析。采用余能范数对马吉拱坝的整体稳定性进行评价,采用不平衡力对左右坝趾及基础中峰值振动速度回归趋势对比软弱带的稳定性进行分析,并对软弱带进行敏感性分析。结果表明,马吉拱坝的位移、应力和超载稳定能力均达到稳定要求,马吉拱坝现施工方案基本可行。

ANALYSIS OF GLOBAL STABILITY OF MAJI ARCH DAM BASED ON NONLINEAR FINITE ELEMENTS

Maji hydroelectric power station with the dam height of 290 m is a major station of Nujiang river. The geological conditions and rock mechanics environment of Maji arch dam are complex；the stress and the abutment stability are significant for engineering safety. Based on nonlinear finite element analysis and deformation reinforcement theory，three dimensional elastoplastic numerical simulation of Maji arch dam has been carried out with code TFINE. The displacements，stresses and abutment forces of dam under normal working conditions were analyzed. Then the global stability and overloading analysis of dam were made based on complementary energy norm. The dam toe and faults in foundation were analyzed based on unbalanced force. The results show that the displacements，stresses and overloading capacity of Maji arch dam meet the requirement of stability；and the current construction project for Maji dam is feasible.