爆炸地震地面运动竖向加速度的实验研究

摘要

The vertical ground acceleration caused by the seism of the gr ound and the nearground surface explosion is studied experimentally. The 2kg TNT charges are se t and ignited on the ground surface or at different heights above the ground, an d the vertical ground accelerations generated by their explosion seismic effects are measured. The analyses of experimental data show that the amplitude-time h istory envelope of vertical ground acceleration may be approximately described b y a double exponential function, the attenuation of maximum acceleration, whose value and rate is related to the chosen charge form, follows the relation with negative power of the distance. The presented results may provide the theoretica l fundamentals for the description of random excitations in predicating the dyna mic responses of structures to explosion seism.%对地面和地面以上爆炸地震引起的地面竖向振动加速度进行了实验研究。用药量为2k g的TNT药包放置于地面和地面以上不同高度处引爆，通过测试获得了离开爆炸源不同距离处地面的竖向振动加速度。实验数据分析表明，加速度幅值的时间历程可以用一个双指数函数给出近似的包络过程，最大加速度随距离的衰减服从负幂函数关系，其取值和衰减速度与爆炸方式存在一定的联系。所提出的研究结果为爆炸地震效应的结构响应随机振源描述提供了理论基础。