摘要
无煤柱自成巷技术的核心是通过切顶卸压释放顶板中积聚的能量,利用采空区碎胀岩体的承载特性实现成巷围岩自平衡.坚硬顶板条件下,采空区顶板不易及时垮落,存在悬顶距离长、矸石块度大、碎胀不充分等问题.本文以坚硬顶板无煤柱自成巷为背景,首先分析了无煤柱自成巷碎胀平衡机理,得到了采空区矸石不同时段碎胀承载力学方程;然后,建立了坚硬顶板切顶短臂梁结构模型,明确了顶板变形的可控因素.在此基础上,以减小垮落矸石块度、增大碎胀程度为目标,提出了深浅孔耦合聚能爆破、预裂孔双量控制、支架循环加卸载等坚硬顶板碎胀综合调控方法,并于坚硬砂岩组顶板、巨厚砂砾岩顶板以及厚层灰岩顶板条件进行了工程试验.典型坚硬砂岩组顶板矿井朱家峁煤矿1310工作面采用碎胀综合调控系列技术后,矸石初始碎胀系数、残余碎胀系数分别增大了0.7和0.5;沿倾斜方向地表沉降减小了0.33 m;留巷段未出现底鼓、帮鼓等明显矿压显现.其他类型坚硬顶板矿井应用后,采空区顶板垮落及时且充填密实,验证了坚硬顶板碎胀平衡调控的有效性.
The core of the non-pillar mining with automatic entry formation technique is to release the accumulated energy in the roof by cutting and relieving the pressure, and achieve self-balancing of the surrounding rock by utilizing the load-bearing characteristics of the fragmented and bulking rock mass in the goaf. Under the condition of a hard roof, the goaf roof is not easily collapsed in a timely manner, resulting in challenges such as a long hanging roof distance, large block sizes of waste rocks, and insufficient bulking. In this study, conducted within the context of coal pillar-free roadways with a hard roof, the equilibrium law of bulking in non-pillar mining with automatic entry formation was analyzed. The mechanical equations for the bulking and load-bearing capacity of the waste rock in the goaf at different stages were derived. Additionally, a structural model of a short-arm beam for cutting the hard roof was established to identify the controllable factors of roof deformation. Based on this, in order to reduce the collapsed gangue block degree, increase the degree of bulking as the goal, a comprehensive control method for the bulking of a hard roof, consisting of deep and shallow hole coupled energy accumulation blasting, double quantity control of pre splitting holes, and cyclic loading and unloading of supports, was proposed. Engineering experiments were conducted under the conditions of a hard sandstone group roof, a thick sand and gravel roof, and a thick layer of limestone roof. Among them, the 1310 working face of Zhujiamao Coal Mine, a typical hard sandstone roof mine, adopted a series of comprehensive control method for the bulking of a hard roof, resulting in an increase of 0.7 and 0.5 for the initial and residual bulking coefficients of the gangue, respectively. The surface subsidence along the inclined direction decreased by 0.33 m. There were no signs of pressure such as floor heave or side heave in the reserved roadway. The application results of other types of hard roof mines also indicate that the roof collapse in goaf is timely and densely filled, which verifies the effectiveness of comprehensive control method for the bulking of a hard roof.
作者
何满潮
盖秋凯
高玉兵
张星星
HE Manchao;GAI Qiukai;GAO Yubing;ZHANG Xingxing(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2023年第5期831-844,930,共15页
Journal of China University of Mining & Technology
基金
国家自然科学基金项目(52204164)
中国科协青年人才托举工程项目(2021QNRC001)
中央高校基本科研业务费项目(2022XJSB03)。
关键词
坚硬顶板
无煤柱自成巷
切顶卸压
垮落矸石
碎胀调控
hard roof
non-pillar mining with automatic entry formation
roof cutting and pressure relief
collapsed gangue
fragmentation and bulking control
