基于地震波法测定岩体弹性抗力系数

Rock Mass Elastic Resistance Coefficient Measurement Based on the Seismic Wave Method

  • 摘要: 围岩弹性抗力系数是隧道结构设计的重要参数, 其原位测试具有难度大、 费用高的特点。基于此, 文章提出一种根据隧道地震波反射法进行超前地质预报实测的围岩地震波波速计算其弹性抗力系数的方法。首先根据实测地震波波速计算围岩的动弹性参数, 然后利用前人得出的岩体动、 静弹性参数关系计算围岩的静力学参数,以此为基础计算围岩的弹性抗力系数。文章以赣龙汀州隧道为例, 采用上述方法获得了该隧道Ⅲ、 Ⅳ级围岩的弹性抗力系数, 分别为0.54~1.19 GPa/m和0.24~ 7.6 GPa/m。计算数值与我国 《铁路隧道设计规范》 中Ⅲ、 Ⅳ级围岩的弹性抗力系数吻合, 这说明根据地震波反射法进行超前地质预报所获得的围岩地震波波速确定围岩弹性抗力系数是一种可行的方法。

     

    Abstract: The elastic resistance coefficient of surrounding rock is an important parameter of tunnel structure design, and is characteristically difficult and expensive in terms of in-situ testing. A method is proposed for calculating the elastic resistance coefficient based on the measured seismic wave velocity of the surrounding rock in advance geological forecasts based on the seismic reflection method. Specifically, the dynamic elastic parameters of the surrounding rock are calculated using the measured seismic wave velocity, then the static parameters of the surrounding rock are calculated based on the relationship between the dynamic and static elastic parameters of the rock mass, and the elastic resistance coefficient of the rock mass is derived. Taking the Tingzhou tunnel of the Ganlong line as an example, it is determined that the coefficients of the tunnel surrounding rock of grade Ⅲ and Ⅳ are 0.54~1.19 GPa/m and 0.24~7.6 GPa/m respectively. The above calculated values are consistent with the data for elastic resistance coefficients of surrounding rock of grade Ⅲ and Ⅳ specified in the "Code for Design of Railway Tunnels."

     

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