1. State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu　 610065,China; 2. College of Hydraulic and Hydroelec- tric Engineering,Sichuan University,Chengdu　 610065,China; 3. Key Laboratory of Energy Engineering Safety and Mechanics on Disaster,Ministry of Educa- tion,Chengdu　 610065,China; 4. State Key Laboratory of Coking Coal Exploitation and Comprehensive Utilization,China PingmeiShenma Group,Pingdings- han　 467000,China; 5. China PingmeiShenma Group,Pingdingshan　 467000,China

浅部矿产资源日益枯竭,深部地下开采将成为常态。因此,对不同赋存深度,尤其是超千米深煤岩开展系统研究具有重要的工程意义。现有研究大多通过改变围压、温度等条件来模拟岩体所处的外在环境,并未采用真实赋存深度样品开展研究,同时忽略了原位岩体初始结构、物质组成和性质的差异。对取自平顶山矿区己组煤层300,600,700,850和1 050 m五个不同深度的煤岩开展系统试验,研究不同赋存深度煤岩成分、细观结构、瓦斯吸附及声学特性。测试结果表明:随着赋存深度增加,煤的组成和结构发生改变,变质程度增大,结构更为致密,瓦斯吸附能力增强,超声波在其内传播发生散射和折射的几率减少,损耗能量降低,纵波波速增大。该成果可为后续开展不同赋存深度煤岩宏观力学特性相关研究提供借鉴。

With the reduction of shallow resources gradually,a deep mining will be a major way to acquire mineral and energy resources. Therefore,it is of great importance to explore the coal from different covered depths,especially from more than 1 000 meters. Previous studies have commonly simulated the external environment of the rock mass at differ- ent depths by changing conditions such as the confining pressure and temperature. However,these studies did not test the rock samples from different depths and overlooked the initial structure,material composition and properties of in-si- tu rock mass. In this study,the coal samples were collected from one coal seam at five different depths (300,600,700, 850 and 1 050 meters) in a mining area. A series of tests were conducted to assess the effect of depth on the composi- tion,meso-structure,gas absorption and acoustic properties of coal. The results showed that as the depth increased,the compositions and meso-structure changed significantly:the metamorphic grade of the coal increased,and its structure became more compact. With the depth increase,the gas absorption capacity of the coal raised,the probability of ultra- sonic scattering and refraction during wave propagation decreased,thus,the energy dissipation decreased and the ultrasonic longitudinal wave velocity increased. These results lay a foundation for the subsequent studies of the effect of depth on the macro-mechanical properties of coal.

LIU Qianying,ZHANG Ru,WANG Man,et al. Physical properties of coal from different depths[J]. Journal of China Coal Society,2017,42 (8):2101-2109.