二维非测速条件下声发射震源定位方法试验研究

Experimental research on two-dimensional acoustic emission source locating without knowing the velocity profile

针对岩体工程震源定位问题,基于已有的二维非测速条件下声发射震源定位方法,将传感器布设方式由等腰直角三角形改进为任意三角形,实现传感器布设一般化,并将其推广为适用于岩石材料的震源定位方法。开展花岗岩平板定位试验研究,选取3种典型传感器布设方式(等腰直角三角形、一般直角三角形、等边三角形)验证该方法的适用性。结果表明:(1)采用互相关技术能够准确计算相似波形信号之间相位差及声发射信号到达相邻传感器的时延;(2)震源定位结果均分布在实际震源周边,定位误差较小,且6次重复试验定位结果均方差较小,离散性低;(3) 3种传感器布设方式震源定位结果的较优点比例分别为82.6%,84.0%和71.0%。验证了该定位方法在岩石类非连续介质中的适用性与准确性,相关研究成果可为深部围岩开挖诱发的板裂破坏监测定位提供理论支撑。

Aiming at the problem of source locating in rock engineering,the two-dimensional acoustic emission source locating algorithm without knowing the velocity profile by T. Kundu was modified. The shape of sensor cluster was extended from isosceles right triangle to arbitrary triangle for the generalization of the sensor layout. The modified locating algorithm was verified by a series of tests on a granite plate with three typical sensor layouts(isosceles right triangle,common right triangle and equilateral triangle). The results indicate that time delay of similar waveform between the adjacent sensors can be obtained accurately by means of cross-correlation technique. The located sources are close to the actual source. For each synthetic source,the mean square deviation of six repeated tests is very small. The better points ratios of 3 typical sensor layouts are 82.6%,84.0% and 71.0% respectively,which verified the applicability and accuracy of the source locating algorithm in the discontinuous materials like rock.