Research On Compaction Performance Of Mechanical Driven Single Drum Vibratory Roller

In the process of laying the road,the single-drum vibratory roller is one of the very important compaction machines,which is used for the compaction of the base or fill.During compaction,the compacted material is pushed horizontally by the steel wheel,resulting in surface cracks or cracks,especially when the steel wheel is non driving wheel,which affects the compaction quality of the compacted material.Therefore,it is very important to analyze the mechanism of cracks on the surface of compacted material for improving or improving the performance of single drive vibratory roller.Based on the shear strength theory of soil and the interaction model of vibratory wheel and soil,the calculation formulas of normal stress and shear stress of soil under the non driven steel wheel are obtained,and the main factors affecting the shear strength of soil are analyzed theoretically.The shear strength test of graded soil is completed.The test results show that moisture and dry density are the two main factors that affect the shear strength of graded soil.Under the same water content,with the increase of dry density,the shear strength parameter cohesion c and internal friction angleφof the graded soil increase accordingly.With the same dry density,the shear strength parameters c and?of graded soil decrease.The value of cohesion c of graded soil samples is approximately exponentially correlated with water content w,the value of internal friction angleφis approximately linearly correlated with water content w,and the value of cohesion c of graded soil and the value of internal friction angleφare There is a linear relationship between dry density?_d.The fitted functional relationship can be used to calculate the normal stress and shear stress of the soil under the non-driving steel wheel.The vibration compaction test of the single-drum vibratory roller was completed,and the crack width,crack interval,compaction degree and settlement of the compacted soil were measured.The test results show that the degree of compaction increases with the increase of the number of compaction passes.After twelve times of compaction,the average compaction degree of the surface layer was 93.25%,the average compaction degree at the depth of 20 cm was 94.14%,and the average compaction degree at the depth of 40 cm was 91.33%.The cumulative settlement increases with the increase of the number of compaction passes,and the relative settlement decreases with the increase of the compaction passes;the soil vertical stress amplitude decreases with the increase of soil depth;The magnitude of the directional stress increases as the number of compaction passes increases.Using the results of the positive pressure test,the soil shear stress at different times of compaction was calculated,and the calculation results showed that the shear stress it received exceeded the shear strength value.The crack width of the compacted surface gradually decreases with the increase of the number of compaction passes.The reason is that as the density increases,the shear strength of the soil increases,and the shear resistance of the non-driven steel wheel increases.