Study On Dynamic Response Of Earth-rock Dam Under Traffic Load

With the development of China’s water conservancy industry and traffic road industry,earth-rock dams and gravity dams all require a certain traffic carrying capacity of the dam crest roads,and the load-bearing vehicles can pass safely and comfortably at a certain speed.The traffic load has a great influence on the dam body,which is easy to produce irreversible deformation.To ensure the safety of the project,it is of great significance to analyze the influence of traffic load on the stability of the dam and reveal the change law of the dam under the working condition of traffic load.Because of the huge differences in materials and construction methods between earth-rock dams and conventional fill roadbeds,this poses a higher challenge to the construction of earth-rock dams.By studying the dynamic response law of earth-rock dams,this paper can provide a basis for future earth-rock dam body,road design and project management.As the traffic volume and load capacity increase,the impact of traffic loads on the dam gradually increases.Different from highways and railways,the analysis of earth and rock dam body needs to take into account the effect of seepage,which is simplified into a wetting line.In the modeling,the parameters used were taken in the field and tested in the laboratory,and the dam saturation line was taken into account to model.In terms of the simplification of the load,the car is simplified to a two-sided single wheel for simulation,the contact surface is simplified to a rectangular shape,and the size is simplified to apply a half sinusoidal load.On the basis of reasonable assumptions and simplifications,the dynamic response of the dam under different load and different speed conditions is studied.The conclusions are as follows:(1)As the depth of the subgrade increases,the stress peaks of the selected nodes gradually decrease,and the stress and strain curves show different volatility at different depths.This change indicates that the dynamic stress generated by the car on the dam is attenuated with increasing depth.The depth of influence obtained in this paper is about 5m.(2)The vehicle load of 100 kN and 200 kN is selected as the research object.As the load of the vehicle increases,the stress and strain response of the shallow surface of the dam is severe,and the vertical dynamic stress changes the most.(3)The vehicle loads at speeds of 20km/h,30km/h and 40km/h are selected to study,and it is concluded that the vehicle speed has less influence on the model.(4)When analyzing the displacement time history curves of selected nodes at different depths of the dam body,it is concluded that under the action of traffic load and hydrostatic pressure,the deformation in the middle depth of the dam body is the largest,and the shallow surface and the dam bottom are affected smaller.(5)Due to the influence of seepage in the dam body,the stress and strain changes caused by traffic loads are asymmetrically distributed,and the changes caused by the water-sag slope are significantly larger than those of the backwater slope.