海石湾矿风井井筒含油气岩层突出危险性预测

为了预防砂岩突出，通过实验室测定了油气岩石的力学性质、岩石成分、显微结构、油气含量及透气系数，现场测定了片状岩芯的比例、钻孔变形、油气压力、油气岩石排放半径以及钻孔内油气排放量等． 根据上述多方面的测定结果，综合判断岩石突出的危险程度，为预防岩层突出提供了参数．

Water resistant features of high-risk outburst coal seams and standard discriminant model of mining under water-pressure

It is important to emphasize the value of research in safe mining technology of high-risk water outburst coal seams. We describe briefly current conditions abroad and in China. Based on an Ordovician limestone aquifer with high-risk water outburst seams in the Feicheng coal field, we analyzed the water-resistant characteristics of a coal floor aquifuge and the behavior of water head intrusion of a confined aquifer and propose a safe criterion model and relevant technology of mining above aquifers. This has brought satisfactory results in engineering practice.

Study of the features of outburst caused by rock cross-cut coal uncovering and the law of gas dilatation energy release

To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the equations of elastic potential of coal and gas dilatation energy theory were set up to process a contrast calculation of the sizes of two kinds of energy. The results show that gas dilatation energy is the uppermost energy source causing outburst occurrence. Furthermore, the mathematical model of spherical flow field gas dilatation energy release was established and MATLAB software was applied to make a numerical calculation analysis on the law of gas dilatation energy release. The results indicate that the gas dilatation energy is closely related to gas parameters and its energy index does reflect the possibility of coal seam outburst.

Geotechnical risk management to prevent coal outburst in room-and-pillar mining

A coal outburst is a severe safety hazard in room-and-pillar mining under deep cover. It is more likely to occur during pillar retreating. Multi-seam mining dramatically increases the risk of coal outburst within the influence zones created by remnant pillars and gob-solid boundaries. Though coal outburst is generally associated with heavy loading of coal pillars,its occurrence is difficult to predict. Risk management provides a proactive tool to minimize coal outburst in room-and-pillar mining under deep cover. Risk assessment is the first step in identifying and quantifying outburst risk factors. The primary risk factors for coal outburst are overburden depth,roof and floor strength,geological anomalies,mining type,multi-seam mining,and panel width. A risk assessment chart can be used to proactively screen out mining sections with high risk of coal outburst for further analysis. Gob-solid boundaries and remnant pillars are critical factors in evaluation of the coal outburst risk of multi-seam mining. Risk identification,risk assessment,geologic influence mapping,geotechnical evaluation,risk analysis,risk mitigation,and monitoring are essential elements of coal outburst risk management process. Training is an integral part of risk management for risk identification and communication between all the stakeholders including management,technical and safety personnel,and miners.

深立井过瓦斯抽排孔群扰动煤岩层损伤评估与支护优化

针对深立井过受瓦斯抽排孔群扰动的煤岩层工程安全问题,分析了钻孔群对煤岩层的扰动影响,基于损伤力学理论建立了定量的扰动损伤评估模型,对淮北海孜煤矿千米立井过受瓦斯抽排孔群扰动煤岩层的稳定性及井筒掘砌过程进行了数值模拟,根据分析结果优化了受扰动煤岩层的加固与井筒掘砌支护方案。研究结果表明:瓦斯抽排钻孔群对煤岩层的扰动评估应综合考虑钻孔水"冲刷效应"、煤岩体"卸压效应"及"孔群效应",3种效应相互作用使得煤与软弱泥岩受损程度远大于稳定粉砂岩层;煤与软弱泥岩层受瓦斯抽排孔扰动后易于出现大范围失稳;井筒掘砌过相应扰动层位前,可利用瓦斯抽排孔进行预注浆加固受损围岩,通过加强掘进初期支护、提高井壁混凝土抗拉性能及壁后注浆等综合措施确保围岩稳定与支护安全。