长期浸润状态下煤岩损伤机制研究  

Damage evolution mechanism of coal rock under long-term soaking

作　　者：张慧梅[1,2] 夏浩峻 张嘉凡[1] 杨更社[2] 袁超 申艳军 路亚妮 ZHANG Huimei;XIA Haojun;ZHANG Jiafan;YANG Gengshe;YUAN Chao;SHEN Yanjun;LU Yani(School of Science,Xi'an University of Science and Technology,Xi'an 710054,China;School of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;School of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054,China;School of Civil Engineering,Hubei Engineering University,Xiaogan 432000,China)

机构地区：[1]西安科技大学理学院,陕西西安710054 [2]西安科技大学建筑与土木工程学院,陕西西安710054 [3]西安科技大学地质与环境学院,陕西西安710054 [4]湖北工程学院土木工程学院,湖北孝感432000

出　　处：《岩土工程学报》2024年第6期1206-1214,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(12172280,42077274,41907259,42277172);陕西省自然科学基金重点资助项目(2020JZ-53)。

摘　　要：富水状态下煤岩力学性能的持续劣化是导致煤矿水害的重要原因,为探究长期浸润作用下煤岩的渐进损伤特征,以神木地区弱黏煤为研究对象,首先以无压力水浸泡的方式模拟煤岩的长期浸润(15,30,60,120,240 d);然后对干燥及浸润试样进行渐进破坏试验,辅以声发射(AE)监测,定量分析煤岩的软化特性;最后利用扫描电镜(SEM)和核磁共振(NMR)研究不同浸润时长下煤岩孔隙结构的劣化规律。研究表明:(1)煤岩饱和度随浸润时长的增加而增加,增加速度先快后慢,最后达到稳定。(2)随饱和度的增加,煤岩力学性能劣化;饱和后,随浸润时长的持续增加,煤岩力学性能仍持续劣化,表现为抗压强度、弹性模量的减小和累计振铃数的增加;(3)干燥处理后,原状煤岩表面干燥收缩,浸水后吸水膨胀,随着浸润时间的增加,小孔隙逐渐增多,孔隙结构趋于复杂。研究结果可为浸水煤岩失稳破坏问题提供有益参考。The deterioration of the mechanical properties of water-rich coal rock is a predisposition to many mine geologic hazards.To explore the progressive damage characteristics of coal rock under long-term soaking,the weakly caking coal of the Shenmu region is selected as the research object.Firstly,the long-term soaking tests on coal rock are carried out without pressures for 15,30,60,120 and 240 days.Then,the uniaxial compression tests with acoustic emission(AE)monitoring are carried out on the dry and then soaked coal rock to analyze its water-softening characteristics.Finally,the evolution of pore structure of coal rock under different soaking durations is studied using the scanning electron microscope(SEM)and nuclear magnetic resonance(NMR).The results show that:(1)The water saturation of coal rock increases with the duration of soaking,and the increase rate continuously decreases,and tends to a constant.(2)In the process of saturation,the mechanical properties of coal rock deteriorate,and those of saturated coal rock still deteriorate with the increase of the soaking duration,characterized by the decrease of the compressive strength and elastic modulus,and an increase in the cumulative AE ringing numbers.(3)A surface shrink may occur after the drying process,and during the soaking tests,the small pores of samples gradually increase,and the pore structure becomes more complex with the increase of the soaking duration.The research results can provide useful prevention for the instability and failure of coal rock under water-rich conditions.

关 键 词：煤岩 浸润时长 力学特性 多尺度 损伤机制 

分 类 号：TU452[建筑科学—岩土工程]