刘宁

摘 要：针对平朔矿区4号煤层的实际赋存情况，研究浅埋深特厚煤层综放开采时，为提高其在综放开采过程中顶煤冒放性，运用FLAC 3D数值试验，采用正交试验方法，对影响顶煤破坏的煤厚、埋深、工作面长度、支架支撑力和煤单轴抗压强度等五个因素进行试验，研究结果为：得出了各个因素对顶煤破坏的影响规律;顶煤破坏综合指标定义是合理的。通过改变可变因素的数值大小，可有效提高顶煤冒放性，为实际综放开采提高回采率提供参考。

关键词：综放采场;顶煤破碎;FLAC 3D

中图分类号：TD355     文献标识码：A     文章编号：1003-5168（2021）36-0066-04

The Analysis of Factors Affecting Top Coal Breakage in Fully Mechanized Caving Stope of Shallow Deep and Thick Coal Seam

LIU Ning

（Equipment installation branch of China Coal Pingshuo Development Group Co. ，Ltd， Shuozhou Shanxi 036001）

Abstract：In view of the actual occurrence of No.4 coal seam in Pingshuo mining area，this paper studies the length of the working face with thick buried depth which affects the failure of top coal in order to improve the caving ability of top coal in fully mechanized caving mining of shallow and thick coal seam Five factors，such as support support force and coal uniaxial compressive strength，are tested.The results are as follows：the influence law of each factor on top coal failure is obtained.The comprehensive index definition of top coal failure is reasonable.By changing the value of variable factors，the caving property of top coal can be improved effectively，which provides reference for improving recovery rate of fully mechanized caving mining in practice.

Keywords：fully-mechanized sublevel caving face;top coal damage;FLAC 3D

依據放顶煤开采相关理论，顶煤的冒放性是决定放顶煤开采回采率的关键所在，而提高顶煤的冒放性的前提条件是必须保证顶煤能有效破碎[1]。

依据对综放开采中顶煤冒落相关研究规律，顶煤冒落受诸多因素影响，既有内部因素，也有外部因素。其中，影响顶煤冒放性主要因素有煤层埋藏深度、煤层强度、煤层厚度、支架初撑力和工作面长度布置等。

煤层赋存深度直接影响着原岩应力的大小，煤层埋藏深度越深，煤层内的原岩应力值越大，顶煤越容易碎裂，顶煤的冒放性越好。

顶煤较薄时，会随采随冒，有利于提高煤炭回收率。随着顶煤厚度越大，上部顶煤将很难得到充分松动破碎，冒放性变差。

煤层的抗压强度愈大，其内摩擦角和黏结系数愈大，其稳定性越强，越不容易碎裂，影响顶煤冒放性。

按煤层开采理论，工作面矿山压力随着工作面长度变长而变大，随之，顶煤越容易破碎[2]，支架上的顶煤冒放性越好。……