爆炸波在非饱和钙质砂中的传播规律

以球形TNT药包作为爆源，在密实的非饱和钙质砂中进行了一系列大尺寸爆炸模型试验。主要研究在不同药包质量、埋深及砂土试样含水率条件下，密实钙质砂中爆炸波的主要基本参数随传播距离增加而变化的规律。试验结果表明爆炸波主要以弹塑性波的形式在密实钙质砂中传播，在干燥和潮湿试样中塑性纵波波速随试样初始密度的增大或含水率的降低而增大，且范围分别为250～282 m/s和302～339 m/s。集团装药情况下，非饱和钙质砂中封闭爆炸的临界比例埋深约为2.25 m/kg1/3。在试验范围内，密实钙质砂中爆炸波的法向应力峰值及法向比冲量的衰减均服从爆炸相似律。封闭爆炸时，干燥钙质砂中爆炸波的应力衰减指数在测点比例爆心距大于或小于0.75 m/kg1/3处分别为2.94或1.37；潮湿钙质砂中爆炸波的应力衰减指数随含水率升高而增大，其范围为1.39～1.79。法向比冲量衰减指数随试样含水率升高而减小，其范围为0.97～1.18。

The propagation laws of blast wave in unsaturated calcareous sand

A series of large-scale explosion model tests were carried out in dense unsaturated calcareous sand using spherical TNT explosives. The propagation laws of the blast wave in dense calcareous sand were studied under various conditions, such as explosive mass, buried depth and water content of sand sample, based on analyzing the changes of major parameters of blast wave. The results show that the blast wave propagates mainly in the form of elastic-plastic wave in dense calcareous sand. Moreover, the plastic longitudinal wave velocity increases with the increase of initial density in the dry sand sample. For the wet sand sample, the plastic longitudinal wave velocity increase with the decrease of the water content. More specifically, the corresponding longitudinal wave velocity ranges from 250 to 282 m/s in the dry sand and ranges from 302 to 339 m/s in the wet sand. In the case of concentrated charge, the critical scaled buried depth of closed explosion in unsaturated calcareous sand is about 2.25 m/kg1/3. In the test range, the attenuations of peak normal stress and specific normal impulse of the blast wave in dense calcareous sand obey the explosion similarity law. The stress attenuation coefficient of blast wave in dry calcareous sand is 2.94 or 1.37 respectively at the measured points whose scaled distances are greater than or less than 0.75 m/kg1/3. The stress attenuation coefficient of explosion wave in wet calcareous sand increases with the increase of water content and ranges from 1.39 to 1.79. The attenuation coefficient of the specific normal impulse decreases with the increase of the sample water content, and the range is 0.97 to 1.18.