基于实测地震波波速的围岩各向异性分析——以赣龙铁路汀州隧道为例

发布时间：2018-02-25 21:04

  本文关键词： 地震波 围岩 各向异性 动参数 结构面　出处：《岩土力学》2016年05期 　论文类型：期刊论文

【摘要】：在赣龙铁路汀州隧道地震波反射法超前地质预报的基础上,选取地震波记录较好的57次测试成果,通过地震波激发炮孔段围岩水平、竖直方向横波波速差异性的统计分析,对围岩的各向异性进行研究。数据分析表明:围岩水平和竖直方向的横波波速不同,表现出不同程度的横波各向异性;赣龙铁路汀州隧道围岩总体上表现出竖直方向的横波波速高于水平方向的各向异性特点,围岩横波各向异性系数绝大部分在±10%以内,动弹性模量、动剪切模量、动泊松比各向异性系数的分布范围分别为-15%~15%、-20%~20%和-20%~15%;围岩的各向异性程度与围岩级别、地震波纵波波速和隧道埋深有较密切的关系;当围岩的地震波纵波波速在3 800~5 000 m/s之间或隧道埋深在60~100 m之间时,横波各向异性系数离散程度较大;在测试的Ⅱ~Ⅴ级围岩中,Ⅳ级围岩的横波各向异性离散程度最高,Ⅱ级围岩的最低。
[Abstract]:On the basis of advanced geological prediction of seismic wave reflection method in Tingzhou Tunnel of Ganlong Railway, 57 test results with good seismic wave record are selected, and the statistical analysis of the difference of shear wave velocity in vertical direction and level of surrounding rock in the borehole section is made by seismic wave. The anisotropy of surrounding rock is studied. The data analysis shows that the shear wave velocities in horizontal and vertical direction of surrounding rock are different, showing different degree of shear wave anisotropy. The shear wave velocity in the vertical direction is higher than that in the horizontal direction, the anisotropy coefficient of the surrounding rock is mostly within 卤10%, the dynamic modulus of elasticity and the dynamic shear modulus of the surrounding rock show that the shear wave velocity of the surrounding rock is higher than that of the horizontal direction in the surrounding rock of Tingzhou Tunnel on the Ganlong Railway. The distribution range of the anisotropy coefficient of dynamic Poisson's ratio is -15% and -20%, respectively, and the anisotropy of surrounding rock is closely related to the level of surrounding rock, the velocity of longitudinal wave of seismic wave and the buried depth of tunnel. When the longitudinal wave velocity of the surrounding rock is between 3 800 ~ 5 000 m / s or the depth of the tunnel is between 60 ~ 100 m, the anisotropy coefficient of the shear wave is large, and the shear wave anisotropy of the fourth grade is the highest in the measured rock of class 鈪，

本文编号：1535135