强夯法加固煤矸石地基动应力模型试验研究

通过强夯法加固煤矸石地基物理模型试验，用 DH5939 动态应变仪完整地记录了强夯每一击作用下煤矸石地基中的 动应力 ，系统地研究了不同夯击能和夯击次数作用下不同深度煤矸石地基动应力的分布特征及其衰减规律。结果表明，在强夯冲击荷载作用下，动应力为单一的波峰，沿夯锤不同深度的动应力达到峰值具有明显的时滞性。强夯动应力在水平方向的衰减速度比竖直方向快，竖直方向的影响范围比平方向大。在相同的夯击能作用下，动应力峰值随深度衰减很快，近似呈负幂指数规律衰减。另外，对不同的测点，在夯击能一定的条件下，随着夯击次数的增加，有效加固范围内的动应力增加明显，但在 3 ～ 6 击后基本稳定。研究为精确模拟分析强夯加固机理提供了有效途径。

Model tests on dynamic stress in colliery wastes improved by dynamic compaction

Through physical model tests on colliery wastes improved by dynamic compaction,the dynamic strain gauge DH5939 is used to record the induced dynamic stress.The distribution and rules of the dynamic stress at different depths under different impact loadings and numbers of dynamic compaction are studied.It is shown that the dynamic stress has a single peak,and it has a significant decay to reach the peak under the impact loadings along the depth of the hammer.The decay speed of the horizontal dynamic stress is faster than that of the vertical one,and the range of influence of the vertical dynamic stress is more extensive than that of the horizontal one.The peak value of the dynamic stress attenuates quickly with the depth and similar in an approximate way of negative exponential decay law under the same tamping energy.In addition,for different measuring points,with the increase of compaction number,the dynamic stress tends to be stable after three to six blows.It may provide an efficient way to analyze the mechanism of dynamic compaction.