Ground response to dynamic compaction of dry sand
Ground response to dynamic compaction of dry sand
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DOI：
10.1680/geot.2002.52.7.481
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发表时间：
2002-09
期刊：
影响因子：
5.8
通讯作者：
Q. Gu;F. Lee
中科院分区：
文献类型：
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作者：
Q. Gu;F. Lee
本文采用二维有限元法，采用大应变动力方程和土的帽盖模型，对强夯机理进行了研究。与离心模型计算结果的对比表明，应力波衰减和改善效果的预测是符合实际的。分析表明，在初始冲击阶段，由于侧向惯性，应力波的传播引起瞬态弹塑性K0压缩。这保持了平面波前，并降低了动态应力随深度的衰减率。随着多次打击，效果改变为三轴压缩：这对近场可以实现的改善程度设置了限制。在更深处，波前呈子弹形状，衰减率上升：这限制了改善的深度。这两种现象是一致的存在的“阈值”状态，已注意到在以前的文献中的强夯。结果还表明，该...
The mechanics of dynamic compaction are studied in this paper using two-dimensional finite element analyses with a large-strain dynamic formulation and a cap model for soil behaviour. Comparison with centrifuge model results shows that stress wave attenuation and improvement effects are realistically predicted. The analyses show that, in the initial blows, stress wave propagation induces transient elasto-plastic K0 compression due to lateral inertia. This preserves the plane wavefront and reduces the attenuation rate of the dynamic stresses with depth. With multiple blows, the effect changes to one of triaxial compression: this sets a limit on the degree of improvement that can be achieved in the near field. Deeper down, the wavefront adopts a bullet shape, and the attenuation rate rises: this sets a limit on the depth of improvement. Both these phenomena are consistent with the existence of a ‘threshold’ state that has been noted in previous literature on dynamic compaction. The results also show that th...