摘要:
现有工作面矿压规律研究主要是针对浅埋深大采高工作面矿压规律和顶板结构进行研究，针对浅埋深综放工作面强矿压显现规律和控制技术研究较少。针对该问题，以某煤矿42202工作面为研究背景，采用工作面支架监测和微震监测相结合的实测方法，研究了工作面的强矿压显现规律：42202工作面的初次来压步距为60 m，周期来压步距为18~26 m，来压时支架动载系数高达1.58，片帮深度达1 100 mm，立柱下缩量为50~80 mm，强矿压导致工作面压架，来压时中部压力大、两侧小，表明工作面来压时矿压显现较为剧烈；微震事件主要集中在工作面超前位置及辅运巷，日累计能量与日频次变化趋势基本相同。分析了浅埋深综放工作面的强矿压机理，指出浅埋深综放工作面强矿压显现的主要原因是采场覆岩高位关键层形成的砌体梁结构与低位关键层形成的悬臂梁结构发生联动失稳效应。针对强矿压显现问题，提出了水压致裂的顶板弱化措施，采取水压致裂措施后，支架工作阻力最大值由59.1 MPa下降到50.1 MPa，降低了约15%；深孔最大应力降低了15%，浅孔最大应力降低了32%，表明水压致裂对顶板弱化和减弱巷道围岩应力有较显著作用。
Abstract:
Current research on mine pressure law of working face mainly focus on mine pressure law and roof structure of large mining height working face with shallow burial depth, but there's few researches on behaviors law and control technology of strong mine pressure of fully mechanized top coal caving mining face with shallow burial depth. For the above problem, taking 42202 working face of a coal mine as research background, behaviors law of strong mine pressure of working face was researched using actual measurement method combining support monitoring and micro-seismic monitoring of working face: the first weighting interval of 42202 working face is 60 m, and periodic weighting interval is 18-26 m. When pressure is weighting, dynamic load coefficient of the support is as high as 1.58, depth of rib spalling is up to 1 100 mm, and shrinkage of the support is 50-80 mm. The strong mime pressure causes working face to crush support. When pressure is applied, the pressure in the middle part is large, while pressure on both sides are small, indicating that mine pressure appears more violently when working face pressure comes; Micro-seismic events are mainly concentrated in the advance position of the working face and auxiliary transportation roadway, and the change trend of daily cumulative energy and daily frequency is basically the same. The mechanism of strong mine pressure of fully mechanized top coal caving mining face with shallow burial depth was analyzed, it is pointed out that the main reason of the strong mine pressure on working face is joint instability effect between "voussoir beam" structure formed by upper key strata and "cantilever beam" structure formed by lower key strata. In view of the problem of strong mine pressure, weakening measure of roof caused by hydraulic fracturing was proposed. After adopting hydraulic fracturing measure, the maximum working resistance of support decreases from 59.1 MPa to 50.1 MPa, reducing by about 15%.The maximum stress of deep hole decreased by 15%, and the maximum stress of shallow hole decreased by 32%, indicating that hydraulic fracturing had a significant effect on roof weakening and roadway surrounding rock stress weakening.
百度学术
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