含孔洞岩样中超声波传播特性的数值模拟研究

Numerical simulation of ultrasonic wave propagation in rock samples with holes

在地下施工过程中,由于岩土体自身存在缺陷,在人工扰动的情况下极易造成失稳破坏。为探究不同孔洞形态下超声波传播特性,利用COMSOL软件建立不同孔洞尺寸、角度和形状模型,分析了单孔洞下尺寸、角度、形状三个单因素变量对超声波传播规律的影响。研究表明:孔洞几何特征对超声波传播产生的影响关系为孔洞尺寸>孔洞角度>孔洞形状;超声波透射信号和波幅透射系数与垂直于声波传播方向孔洞尺寸或面积存在负相关性,表明垂直于声波传播方向孔洞尺寸或面积是造成声波能量衰减的主要原因;声压极大值峰值时间点和大小与孔洞尺寸呈正相关,声压极大值峰值时间点与孔洞角度呈负相关,与峰值大小呈正相关,声压极大值最大峰值时间点和大小与孔洞平行声波传播方向的尺寸呈正相关。

In the process of underground construction,due to the defects of the rock and soil itself,it is very easy to cause instability and damage in the case of artificial disturbance.In order to explore the characteristics of ultrasonic propagation under different hole shapes,the COMSOL software was used to build models with different hole sizes,angles and geometry shapes,and the ultrasonic propagation laws on a single hole rock sample under the influence of three factors were analyzed.The results show that:the influence relationship of hole geometry on ultrasonic propagation is hole size>hole angle>hole shape;there is a negative correlation between the ultrasonic transmission signal and the amplitude transmission coefficient and the hole size or area perpendicular to the sound wave propagation direction,indicating that the hole size or area perpendicular to the sound wave propagation direction is the main reason for the attenuation of the sound wave energy;the peak time point and size of the maximum sound pressure are positively correlated with the hole size,the hole angle is negatively correlated with the peak time point of the maximum sound pressure,and positively correlated with the peak size,the time point and size of the maximum peak value of sound pressure are positively correlated with the size of the hole parallel to the propagation direction of the sound wave.