Experimental Study on the Influence of Soil-Rock Ratio on the Dynamic Compaction Reinforcement Effect of High Fill Gravel Soil Subgrade

To investigate the effect of dynamic consolidation on bearing capacity and settlement deformation of high-fill gravel soil foundation, the gravel soil filler of a high-fill roadbed in Chongqing is taken as the main research object. According to the typical gradation of the site, apply a scale reduction to the filler size. the optimal soil-rock ratio of gravel soil material was determined by compaction test. Through the field dynamic consolidation test, the settling volume of gravel soil foundation and blow count of dynamic sounding under three different soil-rock ratios (4 : 6; 3 : 7; 6 : 4)were studied, and the influence of the soil-rock ratio on the reinforcement effect of dynamic consolidation was discussed. The test results show that the soil-rock ratio is the key factor affecting the compaction quality of the filler and the compaction effect of the soil-rock ratio of 4 : 6 is the best; Under the application of tamping energy of 3000 kN·m, the optimal tamping times of different soil-rock ratios are 7~8, the cumulative tamping settlement of soil-rock ratio 4 : 6 is the largest and the discrete degree of tamping settlement is large; After dynamic compaction, the average blow count of dynamic sounding of gravel soil foundation in the depth of 2~4 m is significantly increased, and the effective reinforcement depth of soil-rock ratio 4 : 6 is the largest; After tamping, the increased range of reinforcement effect under different soil-rock ratios is in the order of soil-stone ratio (4 : 6)> soil-stone ratio (3 : 7)> soil-stone ratio (6 : 4).