A numerical study on 2-D compressive wave propagation in rock masses with a set of joints along the radial direction normal to the joints
A numerical study on 2-D compressive wave propagation in rock masses with a set of joints along the radial direction normal to the joints
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DOI：
10.1016/j.compgeo.2007.01.002
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发表时间：
2007-11
影响因子：
5.3
通讯作者：
W. Lei;A. Hefny;S. Yan;J. Teng
中科院分区：
文献类型：
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作者：
W. Lei;A. Hefny;S. Yan;J. Teng
钻孔中的爆炸或隧道中的意外爆炸会产生一种二维（2-D）压缩波，该波穿过围岩。针对具有平行节理的岩体中二维压缩波沿与节理垂直的径向传播问题，采用通用离散元程序对其传动比和最大回弹比进行了参数化研究。将传动比随接头间距与波长之比的变化规律归纳为特征曲线，可作为估计传动比的预测模型。最大回弹比与影响因素之间的关系以图表形式给出。这些图表可以作为估计最大回弹比的预测模型。所建立的传动比和最大回弹比预测模型已应用于新加坡Mandai现场爆炸试验。利用所提出的沿节理法向传动比预测模型，估计了测点处粒子速度峰值（PPV）的最小可能值。另一方面，利用所提出的沿同一径向方向的最大回弹比预测模型，估计了PPV的最大可能值。结果表明，现场记录的ppv值与Mandai试验监测点的最小可能ppv值和最大可能ppv值估算的ppv值范围吻合较好。估算值与现场实测值之间的良好一致性验证了所提出的预测模型在具有一组节理的岩体中由于在隧道或钻孔边界施加压缩波而产生的峰值颗粒速度的估计。
An explosion in a borehole or an accidental explosion in a tunnel will generate a two-dimensional (2-D) compressive wave that travels through the surrounding rock mass. For the problem of 2-D compressive wave propagation in a rock mass with parallel joints in the radial direction normal to the joints, parametric studies on the transmission ratio and the maximum rebound ratio are performed in universal distinct element code. The variation of the transmission ratio with the ratio of joint spacing to wavelength is generalized into a characteristic curve, which can be used as a prediction model for estimating the transmission ratio. The relationship between the maximum rebound ratio and the influence factors is obtained in charts. The charts can be used as a prediction model for estimating the maximum rebound ratio. The proposed prediction models for estimating the transmission ratio and the maximum rebound ratio are applied to a field explosion test, Mandai test in Singapore. The minimum possible values of peak particle velocity (PPV) at the monitoring points are estimated by using the proposed prediction model for estimating the transmission ratio along the radial direction normal to the joints. On the other hand, the maximum possible values of PPV are estimated by using the proposed prediction model for estimating the maximum rebound ratio along the same radial direction. The comparison shows a good agreement between the field-recorded PPVs and the estimated range of PPVs given by the minimum possible PPVs and the maximum possible PPVs at the monitoring points in Mandai test. The good agreement between the estimated and field-recorded values validates the proposed prediction models for estimating peak particle velocity in a rock mass with a set of joints due to application of a compressive wave at the boundary of a tunnel or a borehole.