极松软煤层抗剪强度的水敏性试验研究

发布时间：2018-03-31 00:34

本文选题：极松软煤层　切入点：煤层注水　出处：《煤炭科学技术》2017年05期

【摘要】：为分析极松软煤层注水防止片帮的效果,研究了极松软煤层注水后抗剪强度的变化。基于非饱和土理论及直剪试验,采用极松软煤体重塑煤样,进行了一系列不同含水率及法向应力下不固结不排水直剪试验的研究,提出了以含水率为中心,以黏聚力和内摩擦角为主要指标的抗剪强度分析方法,采用试验和理论方法综合分析研究了含水率对极松软煤的抗剪强度的影响。研究结果表明:在低法向应力状态下,试样剪应力易发生软化现象,而在高法向应力状态下,试样易发生硬化现象;重塑煤样的黏聚力随含水率的增加先增大,达到最适含水率后(约17.64%),黏聚力随含水率的增加反而减小;含水率对重塑煤样的内摩擦角影响不明显,证实松软煤层注水防止片帮的工程控制技术是有效的。
[Abstract]:In order to analyze the effect of water injection in extremely soft coal seam to prevent the shearing strength, the change of shear strength after injection was studied. Based on the theory of unsaturated soil and the direct shear test, the extremely soft coal body was used to remould the coal sample. A series of unconsolidated and undrained direct shear tests with different moisture content and normal stress were carried out, and a method of shear strength analysis was put forward, which took water content as the center and the cohesion and the angle of internal friction as the main indexes. The influence of moisture content on shear strength of extremely soft coal is studied by means of experimental and theoretical methods. The results show that the shear stress is easy to soften in low normal stress state, but in high normal stress state. The cohesion of remolded coal increases first with the increase of moisture content, and then decreases with the increase of moisture content (about 17.64%), and the effect of moisture content on the internal friction angle of remolded coal sample is not obvious. It is proved that the engineering control technology of water injection prevention in soft coal seam is effective.
【作者单位】：中国矿业大学矿业工程学院;煤炭资源与安全开采国家重点实验室;晋城煤业集团长平煤业有限责任公司;
【基金】：国家高技术研究发展计划(863计划)资助项目(2012AA062101) 教育部新世纪优秀人才支持计划资助项目(NCET-10-0770) 国家自然科学基金资助项目(51074164)
【分类号】：TD823.49

【相似文献】