口孜东矿11-2煤顶板离层实测及层间离层分离

发布时间：2018-07-12 09:35

本文选题：巷道 + 稳定性　；参考：《安徽建筑大学》2015年硕士论文

【摘要】：巷道的稳定性主要与顶板离层有关,而顶板离层分为两类,分别为塑性离层和层间离层。两类离层发生的机理不同,且应对这两类离层所采区的支护特点也有区别。但工程中并不区分两种离层,直接以顶板总离层值作为巷道稳定性的判别标准,给生产安全带来严重隐患。所以研究顶板离层特点,从总离层中分离出塑性离层与层间离层,将对工程实践具有现实意义。本文以口孜东矿11-2煤采区行人上山为工程背景,从以下几个方面对顶板离层进行了研究:首先通过现场取顶板岩芯,进行实验室实验,测定11-2煤顶板岩石力学参数,并初步判断顶板岩层构成及其稳定性。其次以工程实况为模型,采用ANSYS软件对顶板受力情况进行数值模拟,研究巷道顶板应力分布特征,并针对法向拉应力出现位置,对工程实测过程中的测点布置环节进行分析,提出测点优化方案。然后系统分析了塑性离层与层间离层的变形特征,并以此为基础得出两种离层的分离方法。最后采用多点位移计、顶板离层仪等仪器对11-2煤采区进行工程实测,收集实测离层数据后将顶板总离层分离为塑性离层和层间离层,并将总离层与分离后的离层通过列表进行对比分析。得到的主要结论如下:1、口孜东矿11-2煤采区巷道顶板属于典型的复合顶板,顶板岩体的完整度和力学性质都较差,结构面多且含有软弱夹层,因此顶板稳定性低,支护难度较大。2、顶板上方岩层间的法向拉应力是引起顶板离层的主要原因,法向拉应力一般出现在岩体结构面处,尤其是软弱夹层部位其法向拉应力分布范围最广且数值最大。在各岩层之间,垂直于巷道中心位置的拉应力值最大,随着向巷道两帮移动,拉应力递减。3、工程实测中的测点位置选取对离层分析的准确性影响较大,结合顶板拉应力分布特征,得出进行测点布置时,应首先对顶板岩性进行观测,了解岩层大致分布后将测点优先布置在顶板上方软弱夹层附近,其次是各个结构面处。4、在顶板变形初期,塑性离层发展较快,同时其变形速度衰减也快;层间离层在巷道开采初期,形变量较小,但是其变形速度衰减较慢,变形持续时间较长。以此为依据,忽略变形初期0-30d内的顶板层间离层,以实测顶板总离层减去前30d的离层量作为顶板层间离层值;将0-30d内实测的顶板总离层作为塑性离层值。5、通过对口孜东矿11-2煤顶板离层分离,得出了在一般地质条件下,层间离层值较小,顶板总离层与分离后的层间离层数值相差较大,顶板变形主要以塑性离层为主。在顶板软弱夹层以及结构面密集的位置,因法向拉应力较大,顶板变形主要呈现为层间离层。本文的研究成果可为巷道顶板离层临界值的确定以及巷道支护方案的选取提供技术参考。
[Abstract]:The stability of roadway is mainly related to the roof layer, and the roof layer is divided into two categories: plastic layer and interlayer layer. The mechanism of the two types of separation strata is different, and the supporting characteristics of the two types of separation strata are also different. However, there is no distinction between the two kinds of layers in the engineering, and the total roof separation value is taken directly as the criterion for judging the stability of roadway, which brings serious hidden trouble to the safety of production. Therefore, it is of practical significance for engineering practice to study the characteristics of roof layer separation and to separate plastic and interlayer layers from the total separation layer. In this paper, based on the engineering background of walking up the mountain of 11-2 coal mining area in Kou Zidong Coal Mine, the roof dissociation layer is studied from the following aspects: firstly, the rock mechanics parameters of 11-2 coal roof are measured by taking the roof core in the field, carrying out laboratory experiments, and measuring the rock mechanics parameters of the 11-2 coal roof. The composition and stability of roof strata are preliminarily judged. Secondly, the stress distribution characteristics of roadway roof are studied by using ANSYS software, which is based on the model of actual engineering, and the location of normal tensile stress is analyzed, and the layout of measuring points in the process of engineering measurement is analyzed. The optimization scheme of measuring point is put forward. Then, the deformation characteristics of plastic and interlaminar layers are analyzed systematically, and two separation methods are obtained. Finally, the data of 11-2 coal mining area are measured by means of multi-point displacement meter and roof layer separator, and the total roof layer is separated into plastic layer and interlayer layer after collecting the measured data. The total dissociation layer is compared with the separated layer through the list. The main conclusions are as follows: the roof of roadway in 11-2 coal mining area is typical composite roof, the integrity and mechanical properties of roof rock mass are poor, the structure plane is many and contains weak intercalation, so the roof stability is low. The normal tensile stress between the strata above the roof is the main cause of the roof separation. The normal tensile stress generally appears in the rock mass structure plane, especially in the weak intercalation. The normal tensile stress distribution range is the most extensive and the value is the largest. The tensile stress perpendicular to the center of the roadway is the largest among the rock layers, and the tensile stress decreases with moving to the two sides of the roadway. The selection of the location of the measured points in the engineering field has a great influence on the accuracy of the analysis of the separation layer. According to the characteristics of tensile stress distribution of roof, it is concluded that when the measuring points are arranged, the lithology of the roof should be observed first, and then the measuring points should be preferentially arranged near the weak intercalation above the roof after the understanding of the general distribution of the strata. Secondly, at the beginning of roof deformation, plastic dissociation develops faster and its deformation rate decays rapidly, and the deformation of interlayer is smaller at the early mining stage of roadway, but its deformation rate attenuates slowly in the early stage of roadway mining. The deformation lasted longer. On the basis of this, the amount of the total roof separation layer minus the former 30 days is taken as the value of the layer separation between the top layer and the roof layer, which is ignored in the initial deformation period of 0-30 days. Taking the total roof dissociation layer measured within 0-30 days as the plastic dissociation layer value .5, through the separation of 11-2 coal roof separation layer in Zidong Coal Mine, it is concluded that under general geological conditions, the value of interlayer separation layer is smaller, and the difference between the total roof separation layer and the separated layer separation layer value is large. The main deformation of roof is plastic dissociation. In the position of weak intercalation of roof and dense structure plane, the deformation of roof is mainly interlaminar because of the large normal tensile stress. The research results in this paper can provide technical reference for the determination of the critical value of roadway roof separation and the selection of roadway support scheme.
【学位授予单位】：安徽建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD322.4

【参考文献】