大断面硐室围岩变形机理及控制技术研究

发布时间：2018-06-12 00:47

本文选题：大断面硐室 + 尺寸效应　；参考：《北方工业大学》2015年硕士论文

【摘要】：复杂地质条件下大断面硐室围岩变形机理及控制技术是当今地下工程中一项困难的研究课题。硐室断面尺寸大、围岩条件差、构造应力显著及采动应力场分布复杂等因素的影响,使得大断面巷硐与传统的中小断面巷硐相比,存在着更为特殊复杂的围岩变形破坏规律,在硐室掘进过程中常产生一系列严重的围岩变形失稳问题,常规的支护方法已无法满足其使用要求。文章以山西潞安王庄煤矿+540水平井下大断面支架换装硐室为研究背景,分别从大断面硐室围岩变形破坏机理,稳定性控制原理以及支护技术方案等方面入手,采用现场资料收集、理论分析、数值模拟以及现场监测的方法,对复杂地质条件下大断面硐室围岩变形机理及控制技术进行了较为深入的研究,主要成果如下： (1)提出大断面硐室围岩塑性变形计算公式,对大断面硐室围岩塑性变形的尺寸效应进行研究分析。建立FLAC3D数值模型,分析硐室断面面积、围岩性质、构造应力、邻近硐室布置距离等因素对大断面硐室围岩变形,应力和塑性区分布特征的影响规律,揭示大断面硐室围岩变形机理。 (2)结合大断面硐室围岩的变形特征,对大断面硐室开挖围岩变形控制进行研究。首先,对大断面巷硐掘进常用的三种方法(双侧壁导坑法、中隔壁法、正台阶法)进行数值模拟分析,对比三种不同开挖方法下大断面硐室围岩应力及变形破坏特征,得出采用正台阶法开挖能更好的控制硐室围岩稳定性的结论。然后,通过多种围岩控制方案对比分析,提出“加长锚杆、锚索+注浆锚索+底板长锚索”联合支护技术。该方案可使硐室围岩形成多层次承载圈,在提高围岩力学特性的同时充分发挥围岩的自承载能力,很好的保证了硐室围岩的稳定性。 (3)将所提出的围岩控制方案应用到王庄煤矿大断面支架换装硐室开拓延伸实际工程中。对围岩变形监测结果进行分析可知,采用此方案后,硐室围岩稳定性得到了很大的改善。
[Abstract]:The deformation mechanism and control technology of surrounding rock in large section cavern under complex geological conditions is a difficult research subject in underground engineering nowadays. Due to the influence of large section size, poor surrounding rock condition, obvious tectonic stress and complex distribution of mining stress field, the large section tunnel has more complex deformation and failure law than the traditional medium and small section tunnel. A series of serious surrounding rock deformation and instability problems often occur in the process of chamber tunneling, and the conventional supporting methods can no longer meet the requirements of their application. This paper takes the large section support changing chamber under 540 horizontal well of Shanxi Lu'an Wangzhuang Coal Mine as the research background. Starting with the mechanism of deformation and failure of surrounding rock in large section chamber, the principle of stability control and the technical scheme of support, the methods of field data collection, theoretical analysis, numerical simulation and field monitoring are adopted. In this paper, the deformation mechanism and control technology of surrounding rock in large section chamber under complex geological conditions are studied. The main results are as follows: 1) the formula for calculating plastic deformation of surrounding rock in large section chamber is put forward. The size effect of plastic deformation of surrounding rock in large section chamber is studied and analyzed. A numerical model of FLAC3D is established to analyze the influence of factors such as section area of chamber, nature of surrounding rock, tectonic stress and arrangement distance of adjacent chamber on the distribution characteristics of surrounding rock deformation, stress and plastic zone of large section chamber. The deformation mechanism of surrounding rock in large section chamber is revealed. The deformation control of surrounding rock in excavation of large section chamber is studied in combination with the deformation characteristics of surrounding rock in large section chamber. First of all, the numerical simulation and analysis of three common methods (double sidewall tunnel method, middle wall method, positive step method) for large section tunnel excavation are carried out, and the stress and deformation failure characteristics of surrounding rock of large section chamber under three different excavation methods are compared. It is concluded that the stability of surrounding rock of chamber can be better controlled by using step method. Then, through the comparative analysis of various surrounding rock control schemes, the combined support technology of "lengthening anchor rod and grouting anchor cable bottom slab long anchor cable" is put forward. This scheme can make the surrounding rock of the chamber form a multi-layer bearing ring, and give full play to the self-bearing capacity of the surrounding rock while improving the mechanical characteristics of the surrounding rock. The stability of the surrounding rock of the chamber is well guaranteed. The proposed control scheme of surrounding rock is applied to the practical project of the large section support changing chamber in Wangzhuang coal mine. By analyzing the monitoring results of surrounding rock deformation, we can see that the stability of surrounding rock is greatly improved by using this scheme.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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