Experimental Study On Failure Mechanism Of Reinforced Earth Retaining Wall Under Impact Of Rockfall

Rockfall disaster is a common geological disaster in mountainous areas of China.This disaster will seriously threaten the safety of traffic,buildings and people’s lives and property without properly managed.Therefore,it is very important to take reasonable and effective measures to control this disaster.At this stage,the reinforced earth retaining wall has been widely used in civil engineering because of its excellent performance such as good rock interception effect,strong impact resistance,good economy and recoverability.Due to the lack of research on the dynamic response and failure mechanism of reinforced earth retaining wall under the impact load,the design and application of this retaining wall are still based on the traditional theory and engineering experience.Therefore,it is necessary to research the dynamic response and failure mechanism of reinforced earth retaining wall under impact load.In this paper,the dynamic response and failure mechanism of reinforced earth retaining wall under the impact load of rockfall were studied by experimental research,theoretical analysis and numerical simulation.The main contents include:(1)The model test of reinforced earth retaining wall under the impact load of rockfall was carried out.The deformation of the wall,the distribution of the additional stress of the fill,the distribution of the acceleration and the strain of the reinforcement material were obtained through the model test of reinforced earth retaining wall under different impact height.At the same time,the failure mode of the reinforced earth retaining wall was revealed,and the three stages of the failure were analyzed.In addition,the dynamic response and failure mechanism of reinforced earth retaining wall and ordinary semi-rigid rock retaining wall were compared and analyzed.The results showed that the reinforced earth retaining wall has the characteristics of strong absorption of impact energy,better interception effect and better economy than the ordinary semi-rigid retaining wall.(2)The safety and stability analysis of reinforced earth retaining wall was carried out.Based on the characteristics of failure stage evolution of reinforced earth retaining wall model test,this paper proposed a simplified model of failure mode of reinforced earth retaining wall along potential slip surface,and discussed the relevant impact parameters in theoretical analysis.At the same time,the energy method based on the upper limit theorem was used to calculate the safety and stability of reinforced earth retaining wall.The theoretical analysis showed that the reinforced earth retaining wall can make full use of the tensile properties of the reinforcement material to consume the impact energy of rockfall.The safety and stability of reinforced earth retaining wall were greater than that of the ordinary semi-rigid retaining wall.(3)The numerical simulation of reinforced earth retaining wall under the impact load of rockfall was carried out.The ABAQUS software was used to simulate the rockfall impact of reinforced earth retaining wall under the condition of different height,to explore and analyze the dynamic response and failure form of reinforced earth retaining wall.The numerical simulation results showed that with the increase of impact energy(impact height),the initial stage of instability of reinforced earth retaining wall is the deformation of wall,and then develops into the failure stage along the slip surface.