爆破地震波作用下圆形洞室围岩振动速度分布规律

Distribution of Vibration Velocities in Rock Mass of Circular Tunnels Subjected to Blasting Seismic Waves

为了探究岩石开挖爆破地震波作用下邻近圆形洞室的动力响应规律,采用FLAC3D数值模拟软件研究爆破地震波作用下不同埋深圆形隧道洞壁和地表振动速度的缩放规律,以及对不同频率平面简谐P波入射时,隧道洞壁及地表振动速度的分布规律进行研究,并通过理论计算结果的对比分析,检验了数值模拟的可靠性。研究结果表明:隧道埋深会引起隧道洞壁及地表振动速度产生缩放效应:隧道埋深较浅时,隧道洞壁上半部分缩放效应大于下半部分,振动速度放大系数随埋深增加而减小;埋深较深时时,隧道洞壁各位置质点振动速度放大效应随埋深的增加呈现递增规律;地表振动速度放大系数峰值随隧道埋深的增加向背爆侧偏移;迎爆侧洞壁振动速度随入射波频率增加呈增大趋势;地表振动速度放大系数峰值随入射波频率增加向爆源方向偏移。

In order to investigate the dynamic response of adjacent circular tunnels by blast-induced seismic waves, the numerical simulation software FLAC3D was adopted to study the laws of the peak particle velocity（PPV） in the surrounding rock of circular tunnels and surface with various depths, and the laws when time harmonic plane P-waves with various frequencies are also introduced. The results were validated by theoretical results in the same condition. The results show that the PPV in the surrounding rock of circular tunnels and surface are influenced by the depth of tunnel. The depth of tunnel and the frequency of incident waves will influence the distribution of PPV at the tunnel wall and on the ground. The PPV in the surrounding rock of top half circular tunnels is greater than that of bottom half when the depth of tunnel is shallow; the PPV in the surrounding rock of circular tunnels increase with the increase of the tunnel buried depth when the depth of tunnel is deep; the PPV on surface moves to the back-blast side with the increasing of the tunnel buried depth; the PPV in the surrounding rock of circular tunnels increases with the increasing of frequency; the PPV on surface moves to explosion source with the increasing of frequency.