Stress Deformation And Seepage Analysis Of Earth-rock Dam Based On MIDAS/GTS

Because of its simple structure and convenient construction,earth-rock dams are widely distributed in China.The stress deformation and seepage of the dam is the main factor for the safety and stability of the earth-rock dam.For the core wall and the filter layer,the permeable brick is covered in the upstream and downstream,and the filling materials in the upstream and downstream areas are the same,but there is less research on this special earth-rock dam without the transition layer and the secondary rockfill area.A special earth-rock dam Yingwu Reservoir was studied to study the stress deformation and seepage of earth-rock dams.In this paper,the three-dimensional finite element model of the earth-rock dam of Yingwu Reservoir is established by using MIDAS/GTS software.The Duncan-Chang(Duncan-Chang E-B)model is adopted for the dam body and foundation,and the linear elastic model is selected for the concrete material.The two methods of straight wall and inclined core wall are selected to study the stress and strain of the dam;Applying the rational software to analyze the stability of the dam body on the two-dimensional dam slope.The study draws the following conclusions:1.Select two kinds of working conditions in construction period and completion period.The settlement of straight wall in construction period and completion period is smaller than that in inclined wall;the maximum vertical displacement of dam in straight wall construction period is 12.26 cm,which occurs in The middle of the dam is near 1/2 to 1/3 of the top of the dam;the horizontal displacement is lower than the downstream horizontal displacement,but the values are not large;the maximum compressive stress of the dam appears at the bottom center of the dam,and the maximum tensile stress appears at Both sides of the dam are covered with permeable bricks.2.During the water storage period,the displacement calculation is carried out considering three working conditions(normal water storage level,design flood level,and check flood level),the horizontal upstream displacement is reduced,and the horizontal downstream displacement is increased;The settlement displacements are 12.57 cm,12.64 cm and 12.75 cm respectively,which are increased compared with the construction period.The stresses of the three working conditions increase,and the maximum compressive stress of the dam body appears at the bottom center of the dam body,and the maximum tensile stress appears.At the permeable bricks on both sides of the dam,the upstream stress on the same horizontal line is greater than the downstream stress.3.Simulate the calculation of stratified filling and one-time filling construction of the dam.The maximum vertical settlement of the dam once filled is 25.6cm;the maximum vertical settlement of the stratified filling is 12.26 cm.Layered filling is better than one-timefilling.4.Change the parameters such as elastic modulus,failure ratio,cohesion,friction angle of the dam material,and the parameter down-regulation has greater influence on the dam settlement.During the construction of the project,the material strength and construction quality of the dam must be guaranteed.5.Select three working conditions(normal water level,design flood level,check flood level)to calculate the pore water pressure of the core wall,the total head of the dam,the pressure head,and the seepage flow.The overflow point is located above the toe of the downstream from 2~3 meters.The distribution of pore water pressure in the core wall is consistent with the law of seepage deformation.6.Apply the rational software to calculate the stability of the dam on the dam.The calculation results of the two working conditions(normal water storage level,check flood level)are greater than the standard of 1.35,which meets the dam stability requirements.The results calculated in this paper can provide a certain reference for the dam type similar to the structure of this project.