水下钻孔爆破水击波衰减规律及大坝动力响应特征分析

Analysis of the attenuation law of underwater borehole blasting water strike waves and dynamic response characteristics of dams

为研究青狮潭水库附近水下钻孔爆破施工对大坝的影响,采用多物理场仿真软件COMSOL模拟水下钻孔爆破作用过程,建立数值仿真计算模型,对水下钻孔爆破过程中水击波的传播衰减特征进行分析,同时分析水下钻孔爆破过程中地震波作用下水库大坝的动力响应特征。结果表明,在水下钻孔爆破产生的水击波和地震波协同作用下,水域中峰值振动速度随着爆心距增加而呈指数型衰减,水下钻孔爆破水击波的影响范围约200 m;大坝迎爆面底部的动应力响应和峰值应力最明显,振动速度达0.201 cm/s,峰值应力达0.013 MPa。研究结果可为评估水下钻孔爆破过程中水中建(构)筑物的稳定性提供数据支撑。

In order to study the impact of underwater drilling and blasting on the dam of Qing Shitan Reservoir,the multiphysics field simulation software COMSOL was used to simulate the process of underwater drlling and blasting,and a numerical simulation model was established.Based on the established numerical simulation model,the propagation and attenuation characteristics of water shock waves during underwater drilling and blasting were analyzed,and the dynamic response characteristics of the dam under the action of seismic waves during underwater drilling and blasting were also analyzed.The results show that under the synergistic effect of water shock waves and seismic waves generated by underwater drlling and blasting,the peak vibration velocity in the water decays exponentially with the increase of the blast center distance,and the impact range of water shock waves from underwater drilling and blasting is about 200 m.The dynamic stress response and peak stress at the bottom of the blast-face of the dam are the most obvious,with the vibration velocity reaching 0.201 cm/s and the peak stress reaching 0.013 MPa.The peak vibration velocity at the bottom of the dam was much smaller than the blasting vibration safety control value,and the results of the study provided data support for assessing the stability of the building(structure)in water during underwater drilling and blasting.