摘要
强度折减法比极限平衡法理论上更加严密,而局部强度折减法相对于整体强度折减法更加接近岩土工程破坏的实际.为解决深厚覆盖层上碾压混凝土重力坝抗滑稳定计算问题,进一步完善局部强度折减法,针对局部强度折减法中的数值病态、多场耦合求解、初始参数确定、折减过程中相关参数和折减区域动态调整等问题,分别采用h型自适应网格、COMSOL Multiphysics多物理场耦合有限元、粒子群分区反演、渗透率随围压变化、根据应变状态接近屈服的程度及速率大小动态获取折减区大小等一系列措施,提出了改进局部强度折减法.实际工程中河床溢流坝段和左岸岸坡坝段三维有限元模拟结果表明,所提出的方法能克服常规局部强度折减法带来的计算异常,合理获取应急除险加固后大坝的抗滑稳定安全系数.
The strength reduction method is more strict than the limit equilibrium method in theory.Compared with the overall strength reduction method,the local strength reduction method is closer to the actual geotechnical engineering destruction.In order to solve the calculation problem of the anti-slide stability calculation of the roller compacted concrete gravity dam on the thick overburden layer,the local strength reduction method is further improved.In view of the problems of the numerical morbid of the local strength reduction method,the multi-field coupling solution,the initial parameter determination and the dynamic change of the relevant parameters and reduction region in the course of reduction,a series of measures are adopted respectively,such as H type adaptive grid,COMSOL Multiphysics multi-physical field coupling finite element,particle swarm partition inversion,permeability variation with confining pressure,and obtaining the size of the reduction area according to the degree of strain state and the rate of yield dynamically,and then a modified local strength reduction method is proposed.In the actual project,the three-dimensional finite element simulation results of the overflow dam section of the river bed and the bank slope in the left bank show that the proposed method can overcome the calculation abnormality caused by the conventional local strength reduction method and reasonably obtain the anti-sliding stability safety factor of the dam after danger-elimination and reinforcement for emergency.
作者
方卫华
王润英
杜智浩
FANG Weihua;WANG Runying;DU Zhihao(Nanjing Automation Institute of Water Conservancy and Hydrology,Nanjing 210012;Research Center on Hydrology&Water Resources Monitoring,Ministry of Water Resources,Nanjing 210012,China;College of Water Conservancy&Hydropower Engineering,Hohai University,Nanjing 210098,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2020年第1期40-49,共10页
Journal of Basic Science and Engineering
基金
国家自然科学基金项目(51479054)
江苏省自然科学基金项目(BK20151070)
南京水利科学研究院重点基金项目(Y717007).
