Analysis Of The Static And Dynamic Characteristics Of Earth-rock Dams Before And After Earthquake Action

Earth-rock dams are usually used for flood control,power generation and improvement of the surrounding ecological environment.However,most of the earth-rock dams are built in Gorges and earthquake-prone areas.Once the earth-rock dams are damaged by seismic loads,they will cause great disasters to the location of the project and downstream.In this paper,FLAC3 D non-linear elastic-plastic analysis method is used to study the characteristics of earth-rock dams under static loads.Then,the response characteristics of earth-rock dams under seismic loads are studied.Secondly,the response characteristics of earth-rock dams after earthquakes are obtained by comparing the static characteristics with those after earthquakes.A case study of Wangqinghe earth-rock dam project in Yanbian Autonomous Prefecture is carried out before and after earthquakes.The main contents of this paper are as follows:(1)The static-dynamic elastic-plastic analysis method of earth-rock dam is developed to verify the rationality of FLAC3 D program to simulate earth-rock dam.The methods of meshing,selection of constitutive model and selection of physical parameters are studied in detail when building earth-rock dam model by FLAC3 D.(2)Based on the solution of slope safety and stability factor,the basic principles and application scope of three methods,i.e.linear fracture surface method,arc strip distribution method and Bishop distribution method,are analyzed in depth.The influence of different slope gradients on the safety factor of earth-rock dam is studied in detail,and the criterion method for slope instability of earth-rock dam is developed.(3)Deeply study the theory of hydrostatic pressure,based on which the influence of hydrostatic pressure at different heights on earth-rock dams is analyzed concretely.At the same time,the influence of water seepage on earth-rock dams after impoundment is studied,and the pore water pressure at different heights of earth-rock dams is analyzed and studied emphatically.(4)The method of choosing seismic wave,mechanical damping and parameters in dynamic analysis of earth-rock dams is developed.Based on this,seismic wave in different directions(XX direction,YY direction,ZZ direction)and seismic acceleration of different magnitudes(0.4 times,0.6 times,0.8 times,1.0 times,1.3 times,1.4 times,1.6 times)are studied,The influence of dams.(5)The pore water pressure changes of earth-rock dam under the coupling action of seepage,hydrostatic pressure and seismic load have been considered.(6)The Mohr constitutive model and Elar constitutive model are adopted in the case of Wangqinghe earth-rock dam in Yanbian Autonomous Prefecture of Jilin Province.The actual boundary conditions and material parameters are given for specific analysis and study.It is concluded that the dynamic response of the earth-rock dam under local earthquake is safe.