论文部分内容阅读
当矿工被困于封闭的采煤面和巷道时,为了及时联络遇险人员,救护人员往往采取敲击岩体的方式,发出规定的信号,遇险人员也能以同样的方式发出求救的信号。 井下利用敲击岩体所激发的声波,是一种振动波,其频率在200～600赫之间,在岩体中可以穿透5米左右,最高达50米,如果频率相当高,可以传播500米以上,当频率处于超声时,必须有特殊的接收装置才能接收。岩体结构内的弱面愈少,测得的纵波速度愈接近新鲜完整岩体内的测定值。弱面增多,波经多次折射、反射或绕射后才能穿过岩体,因而声波衰减明显。我们可以通过测试波速变化来判断岩体的结构。
When the miners are trapped in the closed mining face and roadway, in order to promptly contact the distress officers, the ambulance personnel often adopt the way of rocking the rock body to issue the prescribed signal and the distress personnel can also send out the signal of distress in the same way. The sound waves excited by the percussive rock mass underground is a type of vibrational wave whose frequency is between 200 and 600 Hz and can penetrate about 5 meters and up to 50 meters in the rock mass and can propagate if the frequency is quite high 500 meters or more, when the frequency is ultrasound, you must have a special receiving device to receive. The less weak face in the rock mass structure, the closer the measured P wave velocity is to the measured value in the fresh intact rock mass. Weak face increased, after repeated refraction, reflection or diffraction can pass through the rock mass, and thus sound attenuation obvious. We can determine the structure of rock mass by testing the change of wave velocity.