Study On Seismic Behavior Mechanism Of Reinforced Earth-Rockfill Dams

Seismic safety of earth-rockfill dams has always been the focus of earth-rockfill dam research.Studies have shown that when the dams are subjected to earthquakes,due to the “whiplash effect”,the seismic response within 1/5 of the top of the dams is greater.At present,the geosynthetic reinforcement technology is widely used in soft foundation reinforcement,embankments,retaining walls and other projects,and has achieved good engineering results and economic benefits.Inspired by this,In the construction of high earth-rockfill dams in earthquake areas,earth-rockfill dams are often reinforced by means of reinforcing the upper part of the dam body.Compared with the traditional anti-seismic reinforcement measures can save a lot of engineering materials.A large number of reinforced earth-rockfill dams are examples double-side reinforced treatment in the upper 1/5 area of the crest.However,for earth-rockfill dams with large water level fluctuations,the upstream side of the dam will easily cause seepage destruction of the dam.In this paper,shaking table test is used to test the unreinforced earth-rockfill dam model,the reinforced earth-rockfill dam model within1/5 of the downstream side of the crest,the reinforced earth-rockfill dam model within2/5 of the downstream side of the crest,and the traditional upper and lower crest of the crest.Analysis of reinforced earth-rockfill dams in the 1/5 range on both sides,comparing the effect of different types of reinforcements on earth-rockfill dams for aseismic reinforcement,and discussing the use of single-side reinforcement for downstream earth-rockfill dams for earth-rock dams with large variations in water level difference.The feasibility of reinforcement treatment.The specific work and achievements are as follows:(1)According to the research status at home and abroad,the analysis methods of dynamic response and static response of earth-rockfill dams are summarized.The theory of friction-reinforcement and quasi-cohesion are used to deeply understand the mechanism of reinforced earth-rockfill dams.Analysis and in-depth discussion of the calculation model and constitutive relationship of reinforced soil.(2)Through analogy,the earth-rockfill dams were respectively reinforced in the non-reinforced,1/5 extent reinforced on the downstream side crest,2/5 extent on the downstream side crest,and the traditional upstream and downstream crests 1/5Acceleration response of the four kinds of reinforced models,deformation of the dam body,strain of the sturdy material,and earth pressure at the bottom of the dam.And draw some regular conclusions.(3)Reinforcement can increase the local stability of the dam crest area,increase the maximum acceleration of the dam body,reduce the displacement of the dam,and inhibit the crest cracking.(4)Increasing the amount of ribs can enhance the seismic capacity of the dam and reduce the occurrence of cracks on the slope surface,so that the sliding surface moves below the reinforced area.(5)The unilateral reinforcement can not only change the local stability of the dam on the reinforcement side,but also have a positive effect on the non-reinforced side,increasing the amount of reinforcement and the range of reinforcement,and this effect is even more pronounced.Therefore,according to the actual needs of the project,for earth-rockfill dams with large variations in water level difference,the earth-rockfill dam can be reinforced by means of one-side downstream reinforcement.