Coupling Simulation Test Of Stone Compaction Process With Strength Difference Based On Discrete Element

As highway construction continues to go deeper into the western mountainous areas,the roadbed construction process often encounters some complex geology,and the strength of the stone materials obtained is different,and the mechanical properties of the stone have a great impact on the quality of the roadbed.In view of this,this study carried out a compacted simulation test based on computer technology.It provides construction parameter optimization and construction scheme for laying high quality roadbed with stone with complex geological strength difference.In this paper,a series of laboratory tests are carried out on the complex geological excavated stone,and the engineering properties of the stone are studied.Secondly,based on the discrete element method and 3D scanning technology,two different strength models of the same shape as the real rock were established.Then,the compaction test simulation of mixed specimens with different strengths of stone was carried out to analyze the influence of the strength of stone on the compaction performance.Finally,the dynamic software and discrete element software are coupled to simulate the compaction process of the vibratory roller on the rock-filled roadbed.The research results are as follows:(1)Compaction simulation test of stone particles with different strengths in large diameter test die,using different compressive strength to press real time,it is recommended to use large pressure to improve the compaction effect;When the mass ratio of high strength stone to low strength stone is 5:5,the compaction effect is the best.Stone particle shape recommended to use all the gravel shape than containing elliptical particles void fraction is lower.(2)In the large-diameter test mold,the compaction test simulation of different strength,particle size and shape of the broken stone particles by vibration action,the same particle size of different stone strength,low strength stone particles more fragile;Different particle size of the same strength stone,small particle stone more easily broken;The particle breakage rate is related to the particle size and strength of rock.(3)vibratory roller compaction process tonnage selection,comparative analysis of 12 t,18t,22 t roller compaction effect,22 t compaction effect is the best,tonnage increase can improve the compaction effect,but high tonnage roller has an optimal number of rolling,rolling too many times will cause voidage rebound,it is recommended to use 22 t roller compaction in the early stage,Later,18 t rolling was used.(4)The selection of the best speed in the compaction process of vibratory roller,comparative analysis of the compaction effect under the rolling speed of 0.6m/s,1m/s,2m/s,before and during compaction,0.6m/s low speed compaction effect is the best,in the later stage of compaction,low speed compaction accompanied by the phenomenon of pushing material,it is suggested to choose the lower rolling speed of 0.6m/s for compaction in the early stage.In the middle and late stage of compaction,use a medium speed of 1m/s rolling speed for compaction.