학술논문
干砂地基初始应力对爆炸波传播影响的模型试验 / Model test on influence of initial stress on blast wave propagation in dry sand foundation
Document Type
Academic Journal
Author
陈加浩; 李俊超; 朱斌; 卢强; 汪玉冰; 管龙华; 赵凤奎; CHEN Jiahao; LI Junchao; ZHU Bin; LU Qiang; WANG Yubing; GUAN Longhua; ZHAO Fengkui
Source
浙江大学学报（工学版） / Journal of Zhejiang University(Engineering Science). 58(3):579-634
Subject
Language
Chinese
ISSN
1008-973X
Abstract
为了研究砂土地基初始应力对爆炸波压力峰值、上升时间、传播速度和初始应力动态卸载等传播规律的影响,开展多组干砂地基常重力和超重力爆炸模型试验.试验结果表明,初始自重应力会抑制爆炸波近区压力峰值的增长,而对远区的影响较小.初始应力的增加使得爆炸波上升时间更长,更易由冲击波衰减为弹塑性波,并使得爆炸波波速增大.超重力试验通过还原砂土地基的原型自重应力,能够模拟爆炸荷载诱发砂土地基初始应力动态卸载的过程,形成爆炸压力和土体初始应力动态卸载拉应力的耦合波,动态卸载拉应力持续时间更长.与爆炸波压应力的比冲量相比,初始应力动态卸载拉应力的比冲量随着传播距离的增加逐渐成为爆炸能量的主要部分,其产生的破坏作用不可忽视.
Several sets of blast model tests were conducted on dry sandy foundation with both normal gravity and supergravity,in order to investigate the effects of initial stress of sandy soil on the propagation characteristics of blast waves,such as peak pressure,rise time,propagation velocity,and dynamic unloading of initial stress.Experimental results showed that the initial self-weight stress inhibited the growth of the peak pressure of the blast wave in the near zone and had little effect on the far zone.The increase of initial stress made the rise time of the blast wave longer and more susceptible to attenuation from the shock wave into the elastic-plastic wave,and the propagation velocity of the blast wave was increased.The supergravity test could simulate the process of dynamic unloading caused by the blast load by restoring the original self-weight stress of the sandy soil,forming coupling wave of explosion pressure and soil initial stress dynamic unloading tensile stress.The dynamic unloading tensile stress lasted longer.The dynamic unloading tensile stress specific impulse magnitude gradually became the main part of the explosion energy with the increase of propagation distance,as compared to the specific impulse magnitude of the blast pressure.The damage effect caused by the dynamic unloading tensile stress specific impulse magnitude cannot be ignored.
Several sets of blast model tests were conducted on dry sandy foundation with both normal gravity and supergravity,in order to investigate the effects of initial stress of sandy soil on the propagation characteristics of blast waves,such as peak pressure,rise time,propagation velocity,and dynamic unloading of initial stress.Experimental results showed that the initial self-weight stress inhibited the growth of the peak pressure of the blast wave in the near zone and had little effect on the far zone.The increase of initial stress made the rise time of the blast wave longer and more susceptible to attenuation from the shock wave into the elastic-plastic wave,and the propagation velocity of the blast wave was increased.The supergravity test could simulate the process of dynamic unloading caused by the blast load by restoring the original self-weight stress of the sandy soil,forming coupling wave of explosion pressure and soil initial stress dynamic unloading tensile stress.The dynamic unloading tensile stress lasted longer.The dynamic unloading tensile stress specific impulse magnitude gradually became the main part of the explosion energy with the increase of propagation distance,as compared to the specific impulse magnitude of the blast pressure.The damage effect caused by the dynamic unloading tensile stress specific impulse magnitude cannot be ignored.