不同断面的巷道对爆破地震波的响应规律数值分析

    Numerical analysis of the response laws of roadways with different sections to blasting seismic wave

    • 摘要: 为了有效减弱爆破地震波对既有巷道的不利影响,需根据巷道对爆破地震波的响应特点采取合理措施。采用数值模拟的方法,研究了正入射爆破地震纵波作用下,不同断面形式巷道的洞壁和围岩振动响应。结果表明,相同爆破地震波作用下,组合式断面巷道的振动响应近似等于对应基本断面式巷道的振动叠加。直墙式巷道的洞壁振速放大效应强于圆形、椭圆形巷道,其振速沿洞壁分布的空间变异性也更大。在迎爆侧,振速放大效应主要发生在距洞壁1倍洞高范围内的围岩体上,距洞壁越近的岩体,振速放大效应越严重。巷道洞壁振动响应对爆破地震波振动频率的变化较为敏感,随振动频率的变化,洞壁振动响应的强度、空间分布均发生变化,由断面几何性质导致的振动响应差异也随振动频率的增加而增大。

       

      Abstract: In order to effectively reduce the adverse effects of blasting seismic waves on existing roadways, reasonable measures should be taken based on the actual response characteristics of roadways to the blasting seismic wave.The response of roadway walls with different sections and surrounding rock mass to the normally incident blasting seismic wave was studied using numerical simulation method.The results show that the vibration response of roadway with composite section is approximately equal to the superposition of which with the corresponding basic section under the same impact.The vibration velocity magnification effect of roadway wall with the section containing straight wall is stronger than that of the circular or elliptical ones, and its spatial distribution variability along the wall of vibration velocity is greater.Vibration amplification effect mainly occurs in rock mass from the distance of 1 times the height of the tunnel wall, and the closer from the wall, the more serious vibration amplification is.The vibration response of roadway wall is remarkably sensitive to the change of vibration frequency of blasting seismic wave.The magnitudes and spatial distribution of vibration response change with the variety of vibration frequencies.Differences of vibration response caused by geometric properties of section increase with the increase of vibration frequencies.

       

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