多次爆破振动下巷道围岩松动圈变化规律研究

Research on Roadway Surrounding Rock Loose Circle Change Law Under Multiple Blasting Vibrations

为了探究巷道围岩在多次爆破振动下松动圈的变化规律,通过单孔超声波测试技术测定了每一次爆破后围岩松动圈的变化范围。根据测试结果确定出8次爆破后各测点松动圈大小相比爆破前平均增大了2.25%,最终巷道围岩松动圈范围为1.14 m左右。结果表明:在多次爆破振动的反复作用下,围岩松动圈在增大,但并不是每一次爆破振动都会引起围岩松动圈的改变。同时对于爆源中远区,爆破振动对各测点松动圈的影响是随机的,和爆心距没有一定的相关性。

In order to explore the roadway surrounding rock loose circle change law under multiple blasting vibrations,we measure the surrounding rock loose circle range by single- hole ultrasonic testing technology after each blast. According to the results of the test,we determined that the loosing circle size after the blasting of the eight times increased 2. 25% averagely compared to that before the blasting. The final scope of roadway surrounding rock loose circle is about 1. 14 meter. Results indicate that： under the action of the repeated blasting vibration wave in the cycle,loose circle are rising. However,it is not every blasting vibration can cause the change of the surrounding rock loose circle. Meanwhile,for far from center of explosion,the influence of loose blasting vibration on the measuring point circle is random,which has no correlation with distance from center of explosion.