卸压爆破下强冲击危险巷道围岩振动规律试验分析

发布时间：2019-07-15 14:47

【摘要】：针对目前参数设计不合理的卸压爆破常常导致巷道围岩损伤破坏,降低防冲效率的问题,采用PASAT-M型便携式微震探测系统,在煤矿井下现场原位开展煤层爆破振动试验,并结合预先加窗短时Fourier变换技术,定量研究卸压爆破下强冲击危险巷道围岩的振动规律。研究表明:(1)在距震源20 m范围内,爆破帮的振动主频随距震源距离的增大呈指数关系增大,顶板的振动主频随距震源距离的增大呈线性关系单调递增,而非爆破帮的振动主频随距震源距离的增大呈二次曲线关系先升高再降低;(2)爆破帮的振幅随距震源距离的增大呈指数关系衰减,超过20 m范围卸压爆破对围岩的损伤破坏效应变得十分微弱;(3)由于巷道各个方位的围岩受到面波和体波的影响程度各不相同,导致了不同方位围岩振动特征(类型、主频和振幅)的差异性;(4)卸压爆炸下巷道各方位围岩的振动类型、主频和幅值并不一致,由此爆破震动波下的损伤破坏效应也有较大区别。结合上述现场实测结果和现有理论,从控制卸压爆破振动的幅值、频率和持续时间3个指标以及增加巷道围岩抗震性能方面,提出优化爆破参数,防止卸压爆破对巷道围岩损伤的建议。
[Abstract]:In order to solve the problem that pressure relief blasting with unreasonable parameter design often leads to damage and destruction of surrounding rock of roadway and reduces flushing efficiency, the vibration test of coal seam blasting is carried out in situ in coal mine with PASAT- M portable microseismic detection system, and the vibration law of surrounding rock of dangerous roadway with strong impact under pressure relief blasting is quantitatively studied in combination with pre-windowed short-time Fourier transformation technology. The results show that: (1) in the range of 20 m from the source, the main vibration frequency of the blasting gang increases exponential with the increase of the distance from the source, and the main vibration frequency of the roof increases linearly with the increase of the distance from the source, while the main vibration frequency of the non-blasting bank increases at first and then decreases with the increase of the distance from the source; (2) the amplitude of blasting gang decreases exponential with the increase of source distance, and the damage and failure effect of pressure relief blasting in the range of more than 20 m becomes very weak. (3) because the surrounding rock in all directions of roadway is affected by surface wave and body wave, the vibration characteristics (type, main frequency and amplitude) of surrounding rock in different directions are different, and the vibration characteristics (type, main frequency and amplitude) of surrounding rock in different directions are caused by the difference of vibration characteristics (type, main frequency and amplitude) of surrounding rock in different directions. (4) the vibration type, main frequency and amplitude of surrounding rock in all directions of roadway under pressure relief explosion are not consistent, so the damage and failure effect under blasting vibration wave is also quite different. Combined with the above field measurement results and existing theories, from the aspects of controlling the amplitude, frequency and duration of pressure relief blasting vibration and increasing the seismic performance of roadway surrounding rock, some suggestions are put forward to optimize blasting parameters and prevent the damage of roadway surrounding rock caused by pressure relief blasting.
【作者单位】：煤炭科学研究总院开采设计研究分院;天地科技股份有限公司开采设计事业部;
【基金】：国家自然科学基金青年基金项目(51204097) 中国煤炭科工集团有限公司科技创新基金项目天地科技“公司开发项目”(KJ 2015 TDKC 05,KJ 2015 TDKC 11)~~
【分类号】：TD324

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