Study On Dynamic Response To Rolling Dynamic Compaction Of Sand

At present,the impact rolling technology has been widely used in the engineering practice of soft foundation,special soil foundation and filled subgrade.However,as an economic,environmental and sustainable foundation treatment technology,impact rolling technology has little research on the mechanism,reinforcement effect and influencing factors of foundation reinforcement,so this paper carries out this research.Based on the development of impact roller compaction model test equipment,this paper studies the sand sample preparation method before impact roller compaction process,the dynamic stress response law in soil during impact roller compaction process and the analysis of displacement response characteristics in soil.The research work in this paper is as follows:(1)The research is based on self-developed rolling dynamic simulation test equipment,which is mainly composed of four parts including model box,model impact wheel,simple buffer device and traction system.The test equipment can simulate the impact rolling process of impact roller,and can be used to study the mechanism of rolling dynamic reinforcement and the influencing factors of rolling dynamic reinforcement effect.(2)The full-scale model test of sand foundation consolidation by rolling dynamic was carried out by using impact rolling simulation test equipment.The forms of impact load and the transmission forms of impact energy along vertical and horizontal directions in soil during rolling dynamic were obtained,and the movement of impact wheels with different shapes and different impact velocities in soil was also obtained.Stress variation characteristics.The research shows that the impact load produced by the impact process of the non-circular impact wheel of the impact roller is a single pulse form,and the impact energy mainly transfers along the vertical direction in the soil,and rapidly decreases along both sides of the impact center.In addition,the impact energy produced by the triangular impact wheel in the process of impact rolling is better than that produced by the quadrilateral and pentagonal impact wheel.(3)The semi-model test of sand foundation consolidated by rolling dynamic is carried out by using rolling dynamic simulation test equipment,and the variationcharacteristics of particle displacement in soil under rolling dynamic are obtained.The research shows that the displacement of impact zone and rolling zone in soil decreases with the increase of depth and horizontal distance,and the horizontal and vertical components of displacement generated by rolling in the whole rolling zone are rapid along the depth direction at different times of rolling.In addition,under the action of triangular and pentagonal impact wheels,the displacement of soil is obviously larger than that of quadrilateral impact wheels,while under the three traction speeds of 0.4m/s,0.7m/s and 1.0m/s,the displacement of soil is basically similar.