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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。
On the basis of the advanced geologic wave reflection method of the Tingzhou tunnel of the Ganzhou-Longzhou Railway, we selected 57 test results recorded by the seismic wave well. Through the statistical analysis of the wave velocity differences between the surrounding rock and the vertical shear wave induced by seismic waves, The anisotropy of surrounding rock is studied. The data analysis shows that the shear wave velocities in horizontal and vertical directions of surrounding rock are different, showing different degrees of shear-wave anisotropy. The surrounding rock of Tingzhou tunnel in Ganlong Railway generally shows the vertical shear wave velocities in horizontal direction For the anisotropy, the anisotropy coefficient of shear wave in the surrounding rock is mostly within ± 10%, and the distribution range of dynamic elastic modulus, dynamic shear modulus and dynamic anisotropy coefficient of moving poisson are -15% ~ 15% , -20% -20% and -20% -15%. The degree of anisotropy of surrounding rock is closely related to the grade of surrounding rock, the longitudinal wave velocity of seismic wave and the tunnel depth. When the seismic wave velocity of surrounding rock is in the range of 3 800 ~ 5 000 m / s or tunnel depth between 60 ~ 100 m, the shear wave anisotropy coefficient is more dispersed. In the tested Ⅱ ~ Ⅴ surrounding rock, the shear wave anisotropy The highest degree of dispersion, the lowest grade Ⅱ rock.