高饱和度饱和土中爆炸波的传播特性

利用φ2．5×5m爆炸模拟装置进行饱和土接触爆炸模拟试验，在获得爆炸波在饱和土自由场中传播的试验数据的基础上，拟合出压力、动量、上升时间随比例距离变化的公式，通过综合分析给出了饱和土中波传播的规律。理论分析揭示了饱和土中应力波传播时出现流体动力区和冲击波形成等性质，建立了饱和土双线性递增硬化本构关系；在饱和土试验中，存在由冲击波向弹性波转化的分界压力，这个分界压力是与介质性质有关的参数，在不同的土中产生冲击波的条件不相同。高饱和度的饱和土中应力波在点爆炸条件下的三维弥散空间中也较容易产生冲击波，因此，在同样的爆炸条件下，饱和土中结构具有更大的破坏可能性。

Characteristics of Blast Wave Propagation in Saturated Soil with High Degree of Saturation

The test simulating contact explosion in saturated soil was completed in the ψ2.5 × 5m pothole. Through the experiment, the data of the free-field in the saturated soil was obtained. The formulas of pressure, momentum and rise time with distance were fitted out based on a large number of test data. According to analysis of the test data, the spreading law of the wave in free-field of saturated soil was obtained. Theoretical analysis showed that saturated soil had the nature of liquid-dynamic area appearing and shock wave forming when the stress wave spread in the saturated soil. The bilinear progressively increasing-harding constitutive relation in saturated soil was established. Dividing pressure was determined and that was the value from shock wave to elastic wave. Moreover, the diving pressure related to media character was different in various soils. Because shock wave was formed easily, the structures in saturated soils had much higher risk of failure under the same explosive conditions.