强夯法加固粉土地基室内模型试验研究

Model test study on silt foundation improvement by dynamic compaction

为了研究强夯法的加固机理和强夯过程中土体的变形规律,根据模型试验的相似第二定理和量纲分析方法,采用半圆模型夯锤,进行强夯法加固粉土地基室内模型试验;分析了不同夯击次数时,夯沉量和影响深度的变化规律,并对夯击时土体内部的动应力进行了研究。试验结果表明,夯锤夯沉量和影响深度均随夯击次数的增加而增加,并且增幅呈平滑的减缓趋势;当夯击数超过11击后,影响深度与夯沉量之比约为3左右;在土层较浅处,动应力衰减较快,而较深处土体,动应力衰减较慢。

In order to analyze the effect of dynamic compaction method on the ground foundation,a series of model tests of silt foundation improvement by dynamic compaction,which is designed by the authors with similarity theory and analyzed method of dimension,is carried out in a model box.The relationships of influence depth,settlement of dynamic compaction and drop numbers,are studied.The dynamic stress during dynamic compaction is also presented.The experimental results show that,by increasing drop numbers,the influence depth and the settlement of dynamic compaction is increasing,and the amplitude is getting smaller and smaller.The influence depth is about 3 times deeper than the settlement of dynamic compaction after 11drops.The speed of attenuation of the dynamic stress is faster in the upper of the foundation than that in the lower of the foundation.