【作者】 张召千；

【导师】 康立勋；

【作者基本信息】 太原理工大学 ， 岩土工程， 2010， 博士

【摘要】 煤巷围岩大多属于层状或块状结构,其本身强度较低,且节理裂隙发育,完整性较差;同时受复杂外部工程环境的影响,煤巷围岩控制和支护越来越成为煤矿生产与安全的重要难题。究其原因,主要存在的问题是:①对煤巷围岩地质力学特性和工程环境条件缺乏准确的掌握和科学的评价;②对煤巷围岩的变形失稳机理的认识不够清楚;③缺乏针对煤巷围岩力学特性的围岩控制和锚固理论;④未能对煤巷围岩的稳定性做出科学有效的评价;⑤煤巷围岩稳定性评价与支护设计不能紧密结合,不能用于指导围岩控制和支护设计。目前人们对特定条件下煤巷围岩稳定性缺乏科学定量的判断手法,缺乏对不同巷道围岩稳定性进行科学评价的理论体系,从而影响煤巷围岩控制和支护效果。因此,深入探讨煤巷围岩稳定性控制及锚固理论,运用岩层控制学及地质力学理论系统研究大断面煤巷围岩的地质力学特性和所处工程环境条件的影响,准确掌握围岩结构及其对围岩稳定性的影响,探索出一条以支护设计为中心的适用于大断面煤巷的围岩稳定性评价体系成为急待解决的技术课题。煤巷围岩稳定性控制与评价的目的是科学准确的反映巷道围岩结构的复杂性,为煤巷围岩控制和支护设计提供可靠依据。总结国内外对煤巷围岩的各种评价方法,发现存在反映的全面性不足,侧重点和选用指标以及分级方法也欠准确。目前国内外对煤巷围岩稳定性控制和评价研究主要表现为如下特点:(1)对煤巷围岩地质力学特性和工程环境条件的研究不够全面和准确,对煤巷围岩的变形失稳机理的认识不够清楚;缺乏针对煤巷围岩力学特征的稳定性控制及锚固理论。(2)围岩稳定性分类现在虽然由单因素定性分级向多因素定性和多因素定量动态模式发展,但影响围岩质量的多种因素具有明显的不确定性、复杂性和模糊性特征,用少数几个固定评价指标和简单的数学表达式难以准确、全面地概括其真实情况,围岩质量的完全定量化分级只能具有数学意义。(3)各类围岩质量的评价方法都是从不同侧面选择几个固定的参评因素,按一定标准进行简单的线性运算,从而得出围岩质量的单一评分,并据此进行围岩稳定性分类。这些方法虽然简单方便,但无法反映复杂多变的地质情况,只能反映围岩稳定性的某一方面特征。由于影响围岩稳定性的因素常具有多层次性、模糊性、不确定性等复杂特点,对于不同地质背景和具体工程,其影响因素及权值都不是固定的,既有共同性,又有特殊性。(4)围岩稳定性的分类主要是针对矿区地质条件下巷道具有的共性进行分析,而在同一矿区甚至同一巷道,巷道围岩状况具有很大的差异,受地质构造和相邻工程环境影响的不同形成局部的特殊性。在同一矿区巷道围岩稳定性各不相同,进行评价时应充分考虑地质构造和工程环境的影响。因此,巷道围岩稳定性评价应当采用静态和动态等多种评价方法从不同侧面进行围岩稳定性的动态评价。在同一矿区进行巷道稳定性评价时应充分考虑个体巷道所处不同的地质构造和工程环境的影响。本文以上述观点为基础,以山西亚美大宁能源有限公司大断面煤巷和矿区地质构造为研究对象,采用理论分析、现场实测、数值模拟计算和工业性试验等方法,对煤巷围岩稳定性控制理论、地质力学评价与支护设计、扰动因素影响加权与修正、数值模拟分析与验证优化等几个方面做了探索性研究;形成了煤巷围岩稳定性控制和动态评价体系。主要研究成果如下:(1)以煤巷围岩地质力学特性为基础,研究煤巷围岩应力分布特征和支护对煤巷围岩稳定性的影响机理,探讨煤巷围岩的变形破坏规律。(2)运用弹塑性理论分析煤巷围岩的稳定性状态,揭示煤巷围岩失稳破坏机理,依据裂隙体及破碎体的煤体力学特征,运用厚板(体)理论进行煤体两帮锚固体厚度、锚杆几何和力学参数设计。(3)研究煤巷在不同围岩稳定性平衡状态下的控制和锚固原理;提出对围岩稳定性状态较好的围岩采用状态控制原理,对稳定性状态差的大变形围岩采用变形控制原理;对围岩整体强度低,围岩应力状态呈静水压力状态的采用整体锚固结构原理。(4)以煤巷围岩控制和支护设计为中心,运用岩层控制学和地质力学理论,采用地质力学评价与支护设计、扰动因素影响加权与修正、数值模拟分析与验证优化,形成了三位一体的巷道围岩稳定性动态评价体系。(5)运用现场取芯和实验室力学测试方法,研究分析15m范围内围岩各岩层的地质力学特性指标。进行煤巷围岩稳定性初步评价和支护方案设计。建立地质力学特性分析—稳定性评价—支护设计为一体的地质力学评价方法。(6)确定了外部扰动因素(地质构造、相邻工程、采动压力)对围岩稳定性影响的重要性;针对煤巷所处工程环境特点,分析地质构造、相邻工程、采动压力外部扰动因素对煤巷围岩稳定性的影响范围及影响等级,确定扰动因素权值,进行影响程度评价和对初步支护方案进行修正,形成了独特的扰动因素加权评价方法。(7)运用数值模拟方法分析煤巷在无支护状态下和在支护方案条件下围岩的应力和变形分布规律。验证煤巷围岩的稳定状态,优化支护设计方案和支护参数。总之,本文通过系统研究,建立了大断面煤巷围岩稳定性控制及动态评价体系,解决了大断面煤巷围岩稳定性控制和支护存在的实际问题,为今后煤巷围岩控制、稳定性评价和支护设计提供科学依据。更多还原

【Abstract】 Most surrounding rocks in coal roadway belong to layered or massive structure with low intensity, joint fissures, and poor integrity; influenced by many project environmental factors simultaneously, it becomes a difficult problem more and more that how to control and support the surrounding rock for production and safety in coal mine. Tracing its reasons, the main problems include:①it lacks accurate mastering and scientific appraisement about geological mechanical properties and project environmental condition;②there is no clear recognition to the deformation destabilizing mechanism of roadway surrounding rock;③there is no enough stability control and anchorage theory aimed at the mechanical properties of roadway surrounding rock;④accurate and scientific appraisement on the stability of roadway surrounding rock cannot be made;⑤the surrounding rock stability appraisement cannot be combined with support design closely and cannot guide the surrounding rock control and support. There is no scientific quantitative judgment technique direct to the stability of roadway surrounding rock under special conditions; it lacks scientific theory system for appraising on the stability of different roadway surrounding rocks, which all influence the stability control and support effect of roadway surrounding rock. Therefore, it is a technique subject pressing for solution to further discuss on stability control and anchorage theory of roadway surrounding rocks, systematically study the influence of geological mechanical properties of surrounding rock in large section roadway and project environmental condition utilizing strata control science and geological mechanical theory, accurately master the structure of surrounding rock and its influence on surrounding rock stability, and taking support design as the central explore a surrounding rock stability appraisement system which is suitable for large section roadway.The surrounding rock stability control and appraisement in coal roadway aims to reflect the complexity of surrounding rock structure scientifically and accurately and to provide a reliable basis for the roadway surrounding rock control and support design. Summarized all kinds of appraisement methods at home and aboard, we can see that those methods had insufficient integrity, the emphasis points, the selected indicators and grading methods were diffident. At present the studies on surrounding rock stability control and appraisement in coal roadway at home and aboard mainly have the following characteristics:(1) The study on geological mechanical properties and project environmental condition of surrounding rock in coal roadway is not very comprehensive and accurate. There is no clear recognition to deformation destabilizing mechanism of roadway surrounding rock. There is no enough stability control and anchorage theory aimed at the mechanical properties of roadway surrounding rock.(2) The classification of surrounding rock stability is developing from the mode of single factor and qualitative graduation to the dynamic mode of multi-factors and quantitative graduation. However, the factors influencing surrounding rock quality have obvious characteristics of uncertainty, complexity and fuzziness. It is difficult to generalize the practical situations accurately and comprehensively by minority fixed appraisement indicators and simple mathematical expressions, and the complete quantitative graduation of surrounding rock quality only has mathematical significance.(3) All kinds of surrounding rock quality appraisement methods select several fixed participating factors from different sides, and carry on simple linear operation according to certain standards, then obtain single scores of surrounding rock quality, and then based on these scores make classification about the stability of surrounding rock. Although these methods are simple and convenient, they cannot reflect the complicated and diversified geological situation, but only reflect one aspect characteristic of surrounding rock stability. The factors influencing the surrounding rock stability usually have complex characteristics of multi-levels, fuzziness, uncertainty, etc. Regarding the different geological backgrounds and the concrete project, their influencing factors and weights are not fixed, which both have the intercommunity and the particularity.(4) The classification of rock stability is founded on analysis mainly on the intercommunity of geological condition in mining areas. However, in same mining area even in same roadway, the rock condition has great difference and each forms partial particularity as result of the different influence of geologic structure and neighboring project environment. The rock stability is different in same mining roadway, so we should consider the influence of geologic structure and project environment completely while carrying on appraisement.Therefore, the stability appraisement of roadway surrounding rock should adopt both static and dynamic appraisement methods to dynamically appraise from different sides. In same mining area we should consider the influence of geologic structure and project environment where the individual roadway locates while carrying on appraisement.Based on the above viewpoints, taken large section coal roadway of Shanxi Yamei Daning energy Limited company and geological structure as the study objects, this paper has adopted theoretical analysis, field measurement, numerical simulation calculation, industrial experiment and other methods to make an exploratory research on the surrounding rock stability control theory in coal roadway, geological mechanical appraisement and support design, the influencing weight and revision of the disturbance factors, numerical simulation and verified optimization, and formed the surrounding rock stability control and dynamic appraisement system. The main research achievements as follows:(1) Based on geological mechanical properties in coal roadway surrounding rock, the paper has studied the characteristic of stress distribution and the mechanism that support influence roadway surrounding rock stability, and discussed on the rule of deformation and destruction of coal roadway surrounding rock.(2) The research has analyzed the stability condition of coal roadway surrounding rock utilizing elastic-plastic theory, exposed the destabilization and destruction mechanism of surrounding rock, and also according to coal seam’s mechanical properties of cracked body and coal body studied how to design the anchorage wall’s thickness, bolts’geometric and mechanical parameters of the broken sides using thick plate theory.(3) The paper has researched the principle of control and anchorage under the different equilibrium states of surrounding rock stability; and suggested adopting the principle of state control for surrounding rock with good stable condition, the principle of deformation control for surrounding rock with bad stable condition, and the principle of whole anchorage structure for surrounding rock with low intensity and hydrostatic pressure state.(4) Taken stability control of roadway surrounding rock and support design as the central, utilizing strata control science and geological mechanical theory, the paper has formed a trinity dynamic appraisement system of roadway surrounding rock stability based on geological mechanical appraisement and support design, the influencing weight and revision of the disturbance factors, numerical simulation and verified optimization.(5) Through taking the core on spot and testing it in the laboratory, the paper has made experimental analysis on each layer’s geological mechanical properties in 15m scope. Also it has made preliminary appraisal on surrounding rock stability and design of support scheme, and constructed the appraisement method based on the trinity of geological mechanical properties of surrounding rock, stability appraisement and support design.(6) The paper has confirmed the importance that the exterior disturbance factors (geological structure, neighboring project) had influence on surrounding rock stability; In view of the characteristic of project environment where the coal roadway locates, the paper has analyzed the influencing scope and graduation of each exterior disturbance factor including geologic structure, neighboring project environment and mining pressure to the stability of roadway surrounding rock, fixed the weight of disturbance factors, appraised the influence and revised the supporting scheme of surrounding rock stability, and formed a unique appraisement system based on the disturbance factor weight.(7) Utilizing numerical simulation analysis, the paper has researched the stress and deformation distribution rule and the characteristic of abscission layer under supporting and non-supporting roadway surrounding rock. And through the analysis on the stability state of surrounding rock, the paper identified and optimized the supporting scheme.In a word, this paper constructed the surrounding rock stability control and dynamic appraisement system of large section roadway through systematic research, which has solved the actual problems existing in the surrounding rock stability control and support of large section roadway and provided a scientific basis for the future control and support of surrounding rock in coal roadway.更多还原