岩体工程特性研究中弹性波速参数取值方法探讨

Study on methods of how to select reasonably elastic wave velocity parameters of engineering rockmass

工程岩体的各向异性特征导致了弹性波速的各向异性。因此,在岩体工程特性研究、岩体质量评价等方面,应注意合理地应用岩体弹性波速资料。笔者分析了岩体波速的各向异性特征,并指出:由于波速各向异性的存在,在岩体完整性系数计算中,岩体波速应取不同方向波速的几何平均值。当利用文中所给公式进行岩体孔隙率计算时,建议波速取最小值;在进行节理、裂隙发育的优势方向判断时,则取不同方向的波速值分别进行计算;当计算弹性模量时,必须取与岩体受力方向相一致的波速值。并给出了利用波速进行有关参数计算的实例。

It should have been paid attention to how to apply reasonably wave velocity data in the research of engineering rockmass characteristics and the appraisal of rockmass quality, etc. for reasons of the anisotropy of elastic wave velocity caused by rockmass anisotropy. The anisotropic characteristics of wave velocity of rockmass are analysed. Geometrical mean of wave velocity in different orientation should be applied in the calculation of sound degree coefficient of rockmass; when using the formula to calculate rockmass porosity, the minimal value of wave velocity is advised; The wave velocity of different orientation can be adopted separately to calculate rockmass porosity and to judge the dominant orientation of joints or cracks. It is necessary that the wave velocity, of which the orientation in accordance with the load orientation of rockess is adopted in the calculation of elastic modulus of rockmass. The examples of calculating rockmass parameters from wave velocity data are discussed.