冲击地压矿井“零冲击”防治研究

Study on “zero coalburst” prevention and control in coalburst mines

  • 摘要: 针对我国冲击地压矿井的安全需求,为落实国家无人员伤亡、无巷道破坏、无设备损坏的“零冲击”管理目标,提出了“零冲击”防治分级目标及技术路径。① 最高目标为“冲击不发生”,技术路径为“应力不超限”。理论推导得到了煤体压缩型冲击地压、顶板拉伸型冲击地压和断层剪切型冲击地压等3类冲击地压的临界应力公式。对“应力不超限”进行分析,系统地研究了3类冲击地压的实际应力与开采条件和地质条件的影响关系,以及临界应力与煤岩变形系统的几何参数和自身物理力学参数的关系。“应力不超限”可通过降低实际应力和提高临界应力实现,并系统地梳理了3类冲击地压降低实际应力和提高临界应力的工程措施。② 基本目标为“冲击不破坏”,技术路径为“能量无剩余”。理论推导得到了3类冲击地压的能量释放和能量吸收公式。对“能量无剩余”进行分析,系统地研究了3类冲击地压的最大释放能量和吸收能量,开展了岩石试样及支护结构的冲击试验,结果表明:岩石试样钻孔结构能够吸收冲击能量,减少岩石试样的整体破坏。吸能装置能够大幅度提高支架吸能能力,吸能装置吸能量占支架总吸能量的78.6%。“能量无剩余”可通过减小冲击地压释放能量和增大围岩与支护吸收能量实现。系统地梳理了减小3类冲击地压释放能量的工程措施,以及增大围岩吸收能量和增大支护吸收能量的工程措施。③ 底线目标为“冲击不伤人”,技术路径为“空间有保障”。分析得到冲击伤人的巷道变形量为:断面收缩率超过20%,支护变形量超过20 cm。“空间有保障”可通过吸能装置实现,吸能装置通过让位变形分担液压支架的冲击变形量可达70%,对巷道支护结构形成保护并将支护变形量控制在20 cm以内。工程措施为:巷道采用吸能液压支架进行加强支护,根据冲击地压最大释放能量、冲击载荷方位以及巷道条件选取合适类型及型号的吸能液压支架。研究证实,“零冲击”防治目标可通过控应力、控能量、控空间实现,为冲击地压矿井实现“零冲击”提供理论与技术支撑。

     

    Abstract: To address the safety needs of coalburst mines in China and fulfill the national “zero coalburst” management objectives of no casualties, no roadway damage, and no equipment damage, this study proposes the hierarchical prevention and control objectives and technical paths for “zero coalburst”: ① The highest objective is “no coalburst occurrence” with the technical path of “no stress overrun”. Through theoretical derivation, critical stress formulas were obtained for 3 types of coalbursts, namely coal compression-type coalburst, roof tensile-type coalburst, and fault shear-type coalburst. An analysis was conducted on “no stress overrun”, systematically investigating the influence relationships between the actual stress of the 3 types of coalbursts and mining conditions as well as geological conditions, and the relationships between critical stress and the geometric parameters of the coal-rock deformation system and its own physical and mechanical parameters. "No stress overrun" can be achieved by reducing actual stress and increasing critical stress; on this basis, engineering measures for reducing actual stress and increasing critical stress for the 3 types of coalbursts were systematically sorted out. ② The basic objective is “no coalburst damage” with the technical path of “no residual energy”. Through theoretical derivation, formulas for energy release and energy absorption of the 3 types of coalbursts have been obtained. An analysis was performed on “no residual energy”, systematically studying the maximum released energy and absorbed energy of the 3 types of coalbursts. Impact tests on rock samples and support structures were carried out, and the results showed that the drilling structure of rock samples can absorb impact energy and reduce the overall damage of rock samples. Energy-absorbing devices can significantly improve the energy absorption capacity of supports, with the energy absorbed by the energy-absorbing devices accounting for 78.6% of the total energy absorbed by the supports. "No residual energy" can be achieved by reducing the energy released by coalbursts and increasing the energy absorbed by the surrounding rock and supports. The engineering measures for reducing the released energy of the 3 types of coalbursts, the engineering measures for increasing the absorbed energy of surrounding rock and supports were systematically sorted out. ③ The bottom-line objective is “no coalburst injuries” with the technical path of “adequate space guarantee”. The roadway deformation values causing coalburst injuries were analyzed and determined as follows: the section shrinkage rate exceeds 20%, and the support deformation exceeds 20 cm. “Adequate space guarantee” can be achieved by energy-absorbing devices. Energy-absorbing devices can share up to 70% of the impact deformation of hydraulic supports through yielding deformation, which protects the roadway support structure and controls the support deformation within 20 cm. The engineering measures are as follows: Roadways shall be reinforced with energy-absorbing hydraulic supports, and the appropriate type and model of energy-absorbing hydraulic supports shall be selected based on the maximum released energy of coalburst, the direction of impact load and the roadway conditions. This study confirms that the “zero coalburst” prevention and control objective can be achieved through stress control, energy control, and space control, providing theoretical and technical support for coalburst mines to realize “zero coalburst”.

     

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