沉积相变岩体声波速度特征的试验研究

声波测试技术发展至今已有30多年的历史,但对声波速度与岩石力学特性相关联的问题研究还只是处于起步阶段。以淮南潘三矿区地质条件为研究背景,以相似物理模拟试验和数值模拟技术为主要研究手段,研究潘三矿区沉积相变岩体声波速度特征及其影响因素,得出岩体中相变体的存在改变岩体应力分布特征:在相变体上部一般为承压区,端部为应力集中区。相变体的存在也使模型中声波速度产生新的分布,相变体上部声波速度较其下部速度大,相变体中声波速度一般较低,经过相变介质声波速度受相变体影响速度变小。研究结果对地下工程声波探测及煤田地震进行精细构造勘探具有重要意义。

EXPERIMENTAL STUDY ON VELOCITY CHARACTERISTICS OF LITHOFACIES TRANSITION ROCK MASS

Based on case of the colliery No.3 of Huainan coalfield in Anhui Province,the relations of sonic velocity and mechanical characteristics of the lithofacies transition rock mass are investigated by the physical modeling study and numerical simulation technique. It is found that the stress and sonic velocity are controlled by the lithofacies and its thickness. During mining processes,the existence of lithofacies transitions in rock mass changes the stress distribution of the roof in the mining faces as follows(:1) the top of lithofacies transition body is artesian flow areas;and (2) the port is located in the stress concentration position. Meanwhile,it shows that the lithofacies transition body influences the sonic velocity of the propagation in the rock mass. Upon the body,the sonic velocity propagating in the rock mass is greater than that in the below. Usually,when the sonic wave passes through the phase transition body,the sonic velocity changes to the lower,which can be used to interpret the detections some geological circumstances in the underground works and seismic exploration.