强夯双向土压力模型试验测试及加固效果分析

Model Test of Vertical and Radial Soil Pressure and Reinforcement Effect Research Under Dynamic Compaction

【目的】从土体应力分布特征的角度研究不同夯击方式对砂土强夯加固效果的影响。【方法】通过室外场地进行的强夯模型试验对夯击过程中土体内部的竖向与径向土压力以及落锤加速度进行监测,并结合数值模拟的方法对土体内部的位移进行分析。【结果】研究得出:在强夯法施工中竖向土压力存在冲击与震荡衰减两种波形,径向土压力则主要以冲击波形为主;在砂土强夯加固过程中存在两种加固模式,夯击点正下方土体主要以竖向压实为主,而斜下方土体同时兼有显著的径向挤密作用;在同能级强夯施工中,“重锤低落”组合适合对深层土体与径向土体进行加固,“轻锤高落”组合适合对浅层土体进行快速加固。【结论】研究成果对同能级强夯夯击方式的选用具有一定的指导意义。

【Purposes】 To investigate the influence of different tamping methods on the reinforcement effect of sand dynamic compaction,this research has been done from the perspective of soil stress distribution characteristics.【Methods】 The dynamic compaction model test was carried out in the outdoor field to monitor the vertical and radial soil pressures in the soil and falling weight acceleration during tamping process,and the displacements in the soil were analyzed by numerical simulation method.【Findings】 It is concluded that in the construction of dynamic compaction method,the vertical soil pressure waveform is the shock wave waveform or the vibration attenuation wave shape,and the radial earth pressure waveform is the impact waveform;There are two reinforcement modes in the process of dynamic compaction,the soil under tamping point is mainly vertically compacted,while the soil side of tamping point also has significant radial compaction;At the same level of dynamic compaction,heavy falling weight is suitable for deep soil and radial soil reinforcement,while light falling weight is suitable for rapid reinforcement of shallow soil.【Conclusions】 The research results have a certain guiding significance for the selection of tamping methods of the same energy level dynamic compaction.