为探求金刚石串珠绳锯煤层割缝卸压增透机理，结合开滦矿区某矿煤层绳锯割缝的工程背景，采用相似模拟试验研究了绳锯煤层割缝缝槽上下方煤岩层裂隙、应力、位移分布特征，建立了煤样3次等压循环加卸载应力-渗透率公式，基于FLAC3D开发了煤层瓦斯渗透率计算程序，通过数值模拟分析了绳锯切割过程中缝槽上方煤层渗透率分布特征及演化规律，研发了金刚石串珠绳锯煤层割缝系统及工艺，开展了大范围连续煤层割缝试验。研究表明：金刚石串珠绳锯切割煤层形成缝槽后，在上方形成较小范围的断裂带和弯曲下沉带，在缝槽上下方煤体中形成了应力降低区，该区内随着远离缝槽其应力变化幅度减小；金刚石串珠绳锯割缝缝槽上方形成了一定范围的增透区，其分布特征是起割位置附近和收割位置附近渗透率提高幅度大，中间部分由于应力恢复的影响煤体渗透率提高幅度较小；缝槽上方区域的渗透率随着至缝槽距离的增加而逐渐降低，达到某一阈值后，割缝对提高煤体渗透率将失去作用；金刚石串珠绳锯煤层割缝效率约80 m2/h，工作效率和连续割缝范围均大于水力化割缝措施。

In order to explore the mechanism of seam pressure relief and permeability enhancement of diamond beaded wire saw cutting in coal seam, combined with the engineering background of wire saw cutting seam in Kailuan Mining Area, similar simulation tests are used to study the distribution characteristics of fracture, the seam cracks and stresses of the upper and lower coal seams of the wire saw coal seam,the stress-permeability formula of coal sample with three isobaric cycles under loading and unloading was established, and a calculation program of coal seam gas permeability was developed based on FLAC3D and the distribution characteristics and evolution law of permeability coefficient of coal seam above the seam slot in the process of wire saw cutting were studied by using numerical simulation method.The seam cutting system and technology of diamond wire saw have been developed, and a large-scale continuous seam cutting test has been carried out. Research results show that after cutting coal seam with diamond beaded wire saw to form seam slots, a small range of fracture zones and curved subsidence zones are formed above, and a stress reduction zone is formed in the upper and lower overburden rocks. The stress variation amplitude decreases as it stays away from the slot; a certain range of anti-reflection zone is formed above the slot, which is characterized by a large increase of permeability near the starting position and the stopping position, and a small increase of permeability in the middle part penetrates due to the effect of stress recovery.The permeability above the slot gradually decreases with the increase of the distance to the slot. When it reaches a certain threshold, the slitting will lose its effect on increasing the permeability. The cutting efficiency of diamond wire saw is about 80 m2/h, and the working efficiency and continuous cutting range are greater than hydraulic slotting measures.

0 引言

1 绳锯煤层割缝相似模拟试验

   1.1 试验原型及试验过程

   1.2 试验结果及分析

2 绳锯煤层割缝下煤层渗透率变化数值模拟

   2.1 数值模拟方法

   2.2 绳锯煤层割缝煤层渗透率变化特征分析

3 金刚石串珠绳锯煤层割缝的工程应用

   3.1 金刚石串珠绳锯煤层割缝工艺简介

4 结论