【作者】 陈辉；

【导师】 王旭春；

【作者基本信息】 青岛理工大学 ， 岩土工程， 2008， 硕士

【摘要】 地下开采是目前我国获得矿产资源的重要途径。在深厚煤层开采中,随着工作面的开采完成,采区的工程环境在不断变化,采空区也越来越大,使得采场的稳定性问题更为突出,而煤柱是决定采场稳定性的重要结构单元,对采空区起支撑作用,不但维护着采场顶板及围岩的稳定性,而且稳定的煤柱对煤炭回采率的提高有极大的潜在作用。其中煤柱煤岩体的流变是确定煤柱长期强度的基础,也是评价采场长期稳定的重要依据。本文对厚煤层开采煤岩体的蠕变特征、长期强度、破坏特征,以及煤岩体结构和围压的变化及时间相依性进行了深入系统的研究。具体内容如下:（1）在煤柱力学响应方面,系统总结煤柱强度和变形规律的各种基础理论,结合煤柱破坏机理分析,得出煤柱载荷与强度是煤柱稳定性分析的基础。（2）通过煤体的流变理论研究,对深厚煤层确定采用改进的Burgers模型—cvisc模型作为煤岩的蠕变模型,初步探讨时间因素对煤柱稳定性的影响。（3）以兴隆庄煤矿主采厚煤层3煤为研究对象,采用FLAC^3D实现开采过程的数值模拟,直观地揭示覆岩和煤柱的位移场、应力场和屈服区的分布情况,通过煤柱的应力应变规律总结和长期稳定性分析,再现采区覆岩、煤柱的变形破坏过程,同时对煤柱破坏特征进行初步探讨。（4）根据蠕变理论分析,建立相应的蠕变模型,结合实验结果确定煤岩体蠕变参数,利用数值模拟得到煤岩体的长期强度指标并进行评价。（5）通过对煤柱蠕变特征的分析,选取应力、应变和塑性区为评价指标,对煤柱稳定程度进行定量的分区判别,为煤矿开采和采后维护采场稳定防护重点提供指导和依据。事实上,采动岩体的变形、破裂、移动整个动态力学过程完全是一种独具特色的流变学现象,而且当前仍然只是从弹塑性方面分析采场的各种变形,本文通过将煤岩体视为粘塑性介质,利用数值分析得到煤柱保持稳定的必要条件和参数,为采煤塌陷区的长期稳定性分析提供理论性和实际性的指导作用。更多还原

【Abstract】 The underground mining is an important way to acquire the mineral resources in our country currently. The mining area of the environment is constantly changing, increasingly mined-out area, and the stability of stope is more important with the face of mining completed in the deep coal mining. The coal-pillar is a pivotal stope unit and it supports stope, so, it not only ensures stability of roof beam and wall rock, but also stability coal-pillar increases the mining rate of coal body obviously. Among them, the coal rock body flows is to determine the long-term pillar of strength, is fundamental evaluation of mining an important basis for long-term stability. The paper carried out the research deeply and systematicly on the creep characteristics of the coal rock in the thick seam of coal mining, long-term strength and damage features, and the coal rock structure and confining pressure changes and time dependence. The specific contents are as follows:（1） In the coal-pillar mechanical response, summarized the various basic theories of the coal-pillar strength and deformation law, comprehensive analysis the coal-pillar destruction mechanism, getting that the coal-loading and strength is the coal-pillar stabilities analytical foundation.（2） Evolution through coal theoretical study, it is determined for the deep coal seam to adopt the improvement Burgers model-cvisc model as the coal-rock creep model. Preliminary study on the time factor to the stability of coal-pillar.（3） With the main 3-thick coal seam in Xinglong Coal Mine as the study object, using FLAC^3D achieve the numerical simulation of the mining process, keep the view ground announce to public the distribution condition of the cover and coal-pillar, in displacement, stress and knuckling under area. Through summary of stress and strain law of the coal-pillar and analysis of long-term stability, reproduction the process of deformation and damage of the cover rock and coal in mining area, while initially discussing the destroy characteristic of the coal-pillar at the same time.（4） According to creep theoretical analysis, build the corresponding creep model, combining the experimental results identified the coal-rock creep parameters. And then using numerical simulation of coal to accept the long-term strength index and evaluate it.（5） Through study the creep characteristic of coal-pillar, select the stress, strain and state zone for the evaluation, determine the stability of coal-pillar in distroct, providing guidance and protection bases for coal mining and mining stope stability after maintaining.In fact, the deformation of mining rock, breaking, moving entire dynamic mechanical process is one kind of the flowing deformation learning phenomenon having a characteristic alone completely. And be only analyzing the various deformation of stope from elastic-plastic aspect currently still. This paper passes to treat the coal-rock as visco-plasticity, making use of numerical analysis to get necessary conditions and parameters with keeping coal-pillar stability, providing theory and actuality directive function for the long-term stability analysis in subsidence area.更多还原