| High earth-rockfill dams will have serious consequences if they are damaged by earthquakes.Therefore,the research on failure mechanism of high embankment dam and seismic strengthening measures has been a hot project.In recent years,geogrid has been wisely applied to construction of earth-rockfill dam,such as Qingfengling reservoir,Nanxunhe Yele hydropower station,Nuozhadu core wall rockfill dam,etc.While,the dam reinforcement schemes often used engineering analogy,which reinforcement mechanism of geogrid reinforced high earth-rockfill dams is not clear,resulting in the lack of theoretical basis for the practical application of the engineering.This paper is supported by the Natural Science Foundation of China（Grant No.51409076）"Dynamic Analysis for High Earth-rockfill Dam with Geogrid Reinforced Based on Generalized Plastic Theory".The article studies the reinforcement effects of geogrid reinforced high earth-rockfill dam under earthquake action to determine the best geogrid laying method.In order to evaluate the stability of the dam body,a method to calculate the dynamic safety coefficient of dam is developed.These research processes use finite difference code(Itcasca-FLAC3D),and verified by examples.The main content of this article is as follow:（1）The deformation of geogrid reinforced high earth-rockfill dam under strong earthquake is analyzed.The calculation results show that the high earth-rockfill dam reinforced by geogrid,its crest settlement,horizontal displacement and vertical displacement have been reduced.By changing the elastic modulus and length of the geogrid and the layer spacing of the geogrid,the optimal geogrid laying method is determined by using the deformation parameters of the dam.（2）The stability analysis of the dam body is carried out by two methods,quasi-static method and dynamic time history method.The results show that the slope slide of dam slope moves towards the inside of the dam and increases the stability of the dam slope,after the geogrid reinforcement.By the time-history analysis,it can be found that with the reinforcement of the dam,the safety factor becomes larger.Then,the optimal geogrid laying method is selected by the stability analysis.（3）Finally,referring to the actual data of Shuangjiangkou dam,the actual engineering dam is reinforced by the optimal geogrid laying method.The calculation results show that the permanent deformation of the dam decreases,the safety factor increases obviously and the ultimate seismic capacity also increases obviously,which verifies the correctness of the method. |
