冲积土中封闭填实爆炸自由场应力波传播特性的实验研究

Propagation Characteristics of Free Field Stress Wave Induced by Confined and Tamped Explosions in Alluvium

为研究冲积土中地下爆炸自由场应力波的传播特性,利用中心起爆的10 kg TNT和30 kg TNT炸药球,开展了3发不同埋深的地下封闭填实爆炸试验,获得了该场地自由场加速度、速度及位移等冲击参数。通过对实测数据的分析得出,不同当量的地下封闭填实爆炸激发的粒子比加速度、粒子速度及粒子比位移符合爆炸相似率,实测加速度、速度及位移参数的峰值约为经验拟合公式的0.4~1.6倍;不同当量爆炸实验获得的粒子速度上升时间不符合爆炸相似率,上升时间与粒子速度峰值和当量均有一定相关性,上升时间和速度峰值之间的关系不能视为材料自身属性;当爆炸当量为基准实验当量的0.3~3.4倍时,可用基准实验测定的上升时间和速度峰值之间的关系来预测评估其他当量爆炸的实验结果,超出上述范围时,预测的结果可能会造成较大偏差。

To study the propagation characteristics of free field stress wave induced by underground explosion in alluvium,three underground confined and tamped explosion tests with different buried depths are carried out by using 10 kg TNT and 30 kg TNT spherical explosive charges detonated at the center.Ground shock parameters,such as acceleration,velocity,and displacement in the test site,are obtained.Through the analysis of the measured data,it is concluded that the peak values of the scaled particle acceleration,particle velocity,and scaled particle displacement induced by the underground confined and tamped explosions with different explosion yields accord with the blasting similarity law.The deviation between the measured stress wave parameters and the empirical fitting formula is proposed.The measured peak values of acceleration,velocity,and displacement parameters are about 0.4 to 1.6 times of the empirical fitting formula.The rising time of particle velocity obtained by the tests with different explosion yields does not accord with the blasting similarity law.The rising time is not only related to the peak velocity,but also to the explosion yields.The experimental results show that when the explosive yields is 0.3-3.4 times of the benchmark experiment,the relationship between the rising time and the peak velocity of the benchmark experiment can be used to predict and evaluate the relevant experimental results of the other test.Beyond the above range,the predicted results may result in large deviations.