Experimental Study And Analysis On Stress Arch Effect In Sand

Sand is a common material in civil engineering.Due to the friction and the rotation characteristics of the particles inside the sand,the direction of the force of the particulate matter will change,forming a stress arch effect and resulting in stress redistribution and stress saturation phenomenon.Based on previous research,this paper analyzes the mechanism of stress arch effect of different factors on the sand by testing the stress of the static sand pile,silo sand pile,sand cushion and retaining wall,and analyzes the stress arch effect A brief analysis of the application in engineering.The research results and conclusions of this article are as follows:(1)The sand piles and silo sand piles formed by localized-source procedure have obvious stress arch effect,which leads to the distribution of compressive stress at the bottom of the sand piles showing central dip and stress saturation of silo sand piles.(2)Through conical sand pile and wedge-shaped sand pile compressive stress test,it is found that the stress dip phenomenon at the bottom of the sand pile caused by the stress arch effect changes with the particle size composition,the shape of sand pile and the method of accumulation.(3)Through the silo model test,the variation law of the bottom saturation stress due to the stress arch effect with the particle size composition,accumulation mode and side wall boundary conditions was obtained,and the stress depression phenomenon at the bottom of the silo was discovered for the first time.(4)Through sand cushions compressive stress and retaining wall side stress and compressive stress test at the bottom of the filler,the non-uniform distribution of sand pad stress due to stress arch effect is obtained,which changes with the pad thickness and sand mechanical parameters(c,φ value),and found the stress depression at the bottom of the filler and the pressure saturation on the side of the retaining wall(5)Based on the non-uniform distribution of stresses obtained from the model tests of sand piles,silos,sand cushions and retaining walls,the analysis of the compressive stress and lateral pressure of foundation cushions and fill retaining walls can be used for engineering design reference.