论文部分内容阅读
钙质砂是一种特殊的海洋沉积物,开展钙质砂在爆炸作用下动力响应特性研究具有重要的理论意义和工程实用价值。通过室内小型爆炸试验,研究饱和钙质砂在爆炸作用下土压力、孔隙水压力和质点振动加速度等参数的变化规律。结果表明:饱和钙质砂中爆炸应力波随距离增大而衰减,但随爆心距增大衰减速度呈减小趋势;随试样相对密度增大爆炸应力波的衰减速度趋缓;爆炸引起的超孔隙水压力在10～30 ms内到达峰值,在前3 min内快速消散,消散幅度达90%以上;双发雷管微差起爆相对于单发起爆,最大单段起爆药量相同,但微差起爆由于爆炸应力波的叠加,使得钙质砂动力响应加剧。与相同试验条件下石英砂爆炸响应对比表明,相同测点处钙质砂动力响应弱于石英砂,应力波在钙质砂中衰减速度远比石英砂快,说明饱和钙质砂对爆炸应力波有着极强的吸收和衰减作用;爆炸近区钙质砂颗粒大量破碎,形成爆炸破碎和压缩区,形成这几个区域所耗损的爆炸冲击能量大约占总能量的25%左右。
Calcareous sand is a kind of special marine sediment. It has important theoretical significance and engineering practical value to study the dynamic response of calcareous sand under explosion. Through indoor small explosion test, the variation regularity of soil pressure, pore water pressure and particle vibration acceleration of saturated calcareous sand under blasting are studied. The results show that the explosion stress wave attenuates with the increase of distance in saturated calcareous sand, but the decay rate decreases with the increase of distance from the center of gravity of the calcareous sand. With the increase of relative density, the decay rate of explosive stress wave slows down. The pore water pressure reached its peak within 10-30 ms and dissipated rapidly over the first 3 minutes with a dissipation range of more than 90%. The differential detonation pressure of double-detonator was the same as that of single initiation and maximum single-stage initiation, but the micro- Poor detonation due to the superposition of explosive stress waves, making the dynamic response of calcareous sand aggravate. Compared with the quartz sand blasting response under the same experimental conditions, the dynamic response of calcareous sand at the same measuring point is weaker than that of quartz sand, and the decay rate of the stress wave in calcareous sand is much faster than that of quartz sand, indicating that the saturated calcareous sand has an obvious effect on the explosion stress wave Has a strong absorption and attenuation; near the explosion of calcareous sand particles a large number of broken to form explosive crushing and compression zone, the formation of these areas consumed by the explosion impact energy accounts for about 25% of the total energy.