采矿与安全工程学报 ›› 2016, Vol. 33 ›› Issue (4): 684-691.

• 论文 • 上一篇    下一篇

沙吉海煤矿弱胶结膨胀性软岩巷道大变形控制对策

  

  1. 1.中国矿业大学(北京)力学与建筑工程学院,深部岩土力学与地下工程国家重点实验室,北京 1000832.湖南科技大学能源与安全工程学院,湖南 湘潭 4112013.华北理工大学矿业工程学院,河北 唐山 063009
  • 收稿日期:2015-10-20 出版日期:2016-07-15 发布日期:2016-07-25
  • 作者简介:郝育喜(1985—),男,安徽省淮北市人,博士研究生,从事冲击地压和深井软岩巷道支护方面的研究。
  • 基金资助:

    国家自然科学基金项目(51374214);国家自然科学基金青年科学基金项目(51404278)

Large deformation control technology for expansive and weak-cemented soft rock roadways in Shajihai coal mine

  • Received:2015-10-20 Online:2016-07-15 Published:2016-07-25

摘要: 针对沙吉海煤矿弱胶结膨胀性软岩巷道开挖后出现冒顶、溃帮和底鼓等严重大变形现象,巷道难以维护的问题,采用X-ray衍射、SEM扫描、物理力学试验和吸水软化试验等方法,研究了弱胶结膨胀性软岩特性;结合现场实际对巷道变形破坏机理进行研究。结果表明:围岩的胶结程度差、膨胀性强、支护强度低,在剧烈开挖扰动作用下传统锚杆索支护与围岩变形不协调,不能充分发挥围岩自身承载能力,是弱胶结膨胀性软岩巷道破坏的主要原因。基于此,采用提高围岩自身承载能力、让压吸能、及时封闭、隔水加固的理念和以恒阻大变形为核心的让压吸能支护原理,提出恒阻大变形锚杆+钢筋网+混凝土喷层+恒阻大变形锚索+底角注浆锚管的支护方案,现场监测表明新支护较好地控制了弱胶结膨胀性围岩变形,应用效果良好。

关键词: 弱胶结软岩, 膨胀性, 恒阻大变形锚杆, 大变形控制, 数值分析

Abstract: The roadways excavated in expansive and weak-cemented soft rocks in Shajihai coal mine have caused serious large deformation problems such as roof failing, side collapse and floor heave in the field. In this paper the X-ray diffraction, SEM scanning, mechanical tests and water absorption tests have been performed to study the characteristics of this soft rock and mechanism of deformation and failure of roadway based on the actual site situation. Research on deformation mechanisms have shown that the main reasons for roadway failure is that the surrounding rocks are with features of weak-cemented and strong swelling ability. When exposed to severe excavation disturbance and low strength support, the surrounding rock cannot match the deformation of the support system by traditional anchor-bolt-mesh support, and the capacity of surrounding rock is wasted in roadway supporting system. Based on the above, the support capacity of surrounding rock has been employed for energy absorbing and ground pressure decreasing, and water isolation for reinforcement has also been performed. Based on the theory of absorbing energy support using Constant Resistance and Large Deformation (CRLD) bolts and anchors, a new support scheme has been put forward, which is the CRLD bolt + mesh + sprayed concrete layer + CRLD anchor + bottom anchor pipe. Field monitoring results have shown that the large deformation of weak-cemented soft rock has been better controlled than before by the application of new support scheme.

Key words: weak-cemented soft rock, expansive characteristic, constant resistance and large deformation bolts, large deformation control, numerical analysis