综放工作面开采速率对围岩应力环境影响的研究

综放工作面开采速率影响着工作面围岩应力重新分布和变形破坏的结果。主要归结于：（1）开采速率的不同影响围岩应力转移过程的完整程度；（2）开采速率的不同造成单位时间开采截深的变化，从而影响了围岩的加卸载过程以及加载速率的变化；（3）开采速率的不同对岩石蠕变时间有一定的影响，从而影响岩石的变形及应力分布。以谢桥煤矿为工程背景，通过数值模拟分析，揭示开采速率对工作面围岩应力影响的规律。随着综放工作面推进速度的增加，工作面周围应力降低区的面积减小：与之对应，工作面周尉岩体破坏区的范围减小工作面前方峰值应力向丁作面靠近，峰值应力变大；围岩岩体的变形时间缩短，工作面周围岩体的位移减小。提出适当提高综放开采推进速度有利于工作面管理和安全生产。

STUDY ON INFLUENCE OF MINING RATE ON STRESS ENVIRONMENT IN SURROUNDING ROCK OF MECHANIZED TOP CAVING MINING FACE

The mining rate affects the results of stress distribution,deformation and failure process in surrounding rocks in mechanized top-caving mining face.The rate effect can be summarized as follows:(1) the completion of stress transition in surrounding rock under different mining rates;(2) the variation of loading and unloading rate in process of different cutting depths in unit period of time;(3) the development of deformation and stress distribution in rock due to creep behavior.Based on the mining state in Xieqiao Colliery,numerical investigation is carried out to reveal the fact that the reduced stress zone around the mining face decreases with the increase of mining rate.Consequently,the failure zone decreases,and the peak stress locates nearer the mining face while the stress value increases.Since the deformation period becomes shorter,as a result,the displacement reduces.The study points out that appropriately increasing the mining rate of mechanized top caving mining face will benefit the mining face management and safe production.