【作者】 龙景奎；

【导师】 蒋斌松；

【作者基本信息】 中国矿业大学 ， 岩土工程， 2015， 博士

【摘要】 深部煤矿开采的一个关键问题是巷道围岩稳定性控制。近年来随着锚固材料、设备和施工技术等方面的发展,锚网索锚固已成为煤矿巷道主导的控制方式。然而,锚固设计仍主要依据经验方法而缺乏基础理论指导,其不足主要体现为：一是锚固系统子系统内部因素之间的协同作用不足,导致子系统功能得不到强化；二是子系统之间的协同作用不足,从而带来锚固系统没有产生协同增强效应,表现出整体效能不足。这样既不能有效保证锚固效果与安全性,也不利于提高掘进效率。论文以煤矿深部巷道工程为研究对象,将协同学原理应用于巷道围岩稳定性控制。首先论证了协同学相关理论应用于巷道锚固系统的可行性、合理性与适用性,建立包含锚固系统、围岩系统和环境系统在内的深部巷道围岩稳定性控制系统；通过分析巷道围岩位移与锚固系统控制变量和状态参量的相互关系,论证以位移作为协同锚固系统序参量的合理性,以此建立深部巷道围岩协同锚固系统的力学模型；协同锚固系统在宏观整体上大于各子系统之简单总和,即产生“1+1>2”协同正效应。在此基础上,论文通过理论分析、模型试验、数值模拟和工程实践等多种方法,多层面、多角度研究协同锚固机理、作用机制和协同效应,建立协同锚固技术体系与评价指标,并多次应用于工程实践和取得良好效益,使协同锚固机理研究与技术应用实现一体化。论文获得以下主要结论和创新成果：(1)通过研究,证明了协同作用和协同效应在巷道围岩锚固系统中的客观存在,并且可以通过调整和优化锚固变量来更好地实现子系统之间的协同作用和锚固系统的协同效应,能够显著地提高巷道锚固岩体的整体强度和刚度,促使巷道变形、围岩应力分布、锚杆(索)受力等都趋于均匀协调,从而明显地提高巷道锚固岩体的承载能力和抗变形能力。(2)提出协同增量△Si和协同指数()的概念和计算方法,并分别作为协同作用和协同效应程度的评价指标。当△Si>0时,表明产生协同作用,其值越大作用越强；当△Si<0时,表明没有产生协同作用或产生负作用；当△Si=0时,表明处于协同作用“临界”状态。对应地,当(?)>0时,表明产生协同效应,且其值愈大,协同效应愈强；当(?)<0时,表明没有产生协同效应或产生负效应；当(?)=0时,表明处于协同效应“临界”状态。(3)通过试验,研究锚杆预紧力、布置密度和组合构件对锚固体的锚固作用,获得了在一定预紧力作用下单根、两根锚杆对锚固体内协同作用、协同效应和应力场分布的作用规律。采用灰色关联分析方法,获知锚杆预紧力与密度共同作用时,锚杆密度对锚固体内产生协同效应范围的影响更为明显。另外,组合构件的使用,能够增强锚固岩体内的协同作用程度和协同效应范围,并让锚固体表面得到更加有效的控制。(4)通过模拟,获知锚杆(索)预紧力、密度、长度、角度等锚固变量内部及相互之间均存在协同作用关系,且当它们之间的协同关系得到满足时,能够使锚固系统产生协同作用和协同效应,从而带来系统功能在宏观整体上大于各子系统、要素之简单总和,而协同关系没有得到满足时则不会产生“1+1>2”的协同效应现象。(5)在锚固变量的协同作用下,沿锚杆钻装方向,锚固体内协同效应范围呈现出轴向长、横向短的“橄榄球”型形状,且协同效应范围随着锚固变量的变化而变化,并在轴向上表现得更为敏感。另外,在非全长锚固作用下,锚固段锚杆与周围岩体通过粘接作用形成一个“大托盘”,并对一定范围内的岩体产生明显的挤压和加固作用,有效提高了锚固岩体的强度和刚度,这一现象的发现也进一步丰富和完善了锚杆加固拱理论。(6)建立锚杆(索)协同锚固作用的实现机制,包括预紧力协同、结构协同、变形协同、锚固时机协同、强度协同、刚度协同和参数设计协同等,获得不同协同作用机制的实现方式。在此基础上,将协同锚固机理及技术应用于工程实践,成功解决了部分深部高应力软岩巷道和其它复杂条件巷道围岩稳定性控制所遇到的难题,取得了良好成效。协同锚固机理是将协同学原理应用于巷道围岩稳定性控制而提出的一个全新概念,这种尝试可给研究者提供一个新的视角,为巷道及类似工程控制机理研究提供一种科学导向和理论依据,并获得可靠、适用而有效的协同锚固技术体系。更多还原

【Abstract】 Stability control of the surrounding rock is one of the key issues in deep coalmining. In recent years, development of anchor material, equipment, and construction techniques has made net- cable anchorage the prevailing control method of roadways. Its design, however, is conducted more by experiences than by the fundamental theory. It leads to two major shortcomings. One is a lack of synergistic effect among the factors within the subsystem of the anchorage system, which fails to maximize the function of the subsystem. The other is a lack of synergistic effect among the subsystems, which brings little synergistic enhancement efficiency to the anchorage system and leads to an insufficient integral effectiveness. As a result, it can neither guarantee the anchoring effect and safety, nor improve drilling efficiency.This thesis studies the deep roadway engineering in the coal mine, and applies synergic principles to stability control of the roadway surrounding rock. It firstly discusses the feasibility, reasonableness and applicability of using synergy in roadway anchorage, and builds a deep roadway stability control system composed of the subsystems of anchorage, surrounding rock and environment. By analyzing the relationship between the displacement of the surrounding rock and the system’s control variable and state parameter, this thesis discusses the reasonableness of using displacement as the system’s order parameter, and thereby builds the system’s mechanical model. The whole anchorage system, macroscopically, achieves more than the simplistic sum of all its subsystems, or the positive synergic efficiency of 1+1 2.On this basis, this thesis makes a multi-level and multi-angle study of the principle, mechanism and efficiency of synergistic anchorage by means of theoretical analysis, model test, numerical simulation and engineering practice. It accomplishes the technical system of synergistic anchorage, and its evaluation index. The whole system performs well in several engineering practices, and achieves integration between the study and its technical application.The thesis draws the following major conclusions.1 The study proves the objective existence of synergistic effect and efficiency in the anchorage system of roadway surrounding rock. What’s more, adjustment and optimization of the anchorage variable can improve both the synergistic effect among the subsystems and the synergistic efficiency of the whole anchorage system, raise significantly the integral strength and stiffness of the anchored rock, and lead to a uniform roadway deformation, a homogeneous surrounding rock stress distribution, and an even load on the anchor bolt(cable). As a result, the anchored rock in the roadway increases greatly its bearing capacity and deformation resistance.2 The study proposes the concept of synergistic incrementi?S and synergistic index iξ, develops their calculation formulae, and adopts them as the evaluation of synergistic effect. When i?S 0, synergistic effect appears and grows as the value rises. When i?S 0, there is zero synergistic effect or even negative effect. When i?S 0, synergistic effect reaches its critical state. Accordingly, when iξ 0, synergistic efficiency appears and grows as the value rises. Wheniξ 0, there is zero synergistic efficiency or even negative efficiency. When iξ 0, synergistic efficiency reaches its critical state.3 Experiments are conducted to study the fixation effect on the anchorage body produced by bolt preload, distribution density and composite members, and find out the working law of synergistic effect, synergistic efficiency, and stress distribution within the anchorage body in case of one and two bolts. With Grey Relational Analysis it is known that when bolt preload and density changes simultaneously, bolt density leaves more obvious influence on the scope of synergistic efficiency within the anchorage body.4 It is known from simulation that synergistic effect exists both within and among such anchorage variables as bolt(cable) preload, density, length, and angle. If they are synergistic, the anchorage system is synergistically more effective and efficient. So the system as a whole functions better than the sum of all its subsystems and single elements. If they are not synergistic, there is no synergistic efficiency of 1 1 2.5 Under the synergistic effect of the anchorage variable, the scope of synergistic efficiency within the anchorage body takes, along the drilling direction of the bolt the shape of an American football which is axially longer and horizontally shorter. As the anchorage variable changes, the scope varies more apparently along the axle. Besides, with the partial length anchorage, the anchoring section and the rock surrounding it form a “big tray” as a result of adhesion. It extrudes and strengthens apparently the rock within a certain range. Thus, the strength and stiffness of the anchored rock rises effectively. This discovery enriches and improves the theory of anchorage reinforcement arch.6 This study establishes the anchorage mechanism to realize the synergistic effect of bolt(cable), including preload synergy, structural synergy, deformation synergy, anchorage timing synergy, strength synergy, stiffness synergy and parameter design synergy. It develops various methods to implement these synergistic mechanisms. On this basis, this study applies the principle and technique of synergistic anchorage to engineering practice, and solves the problems concerning the stability control of the surrounding rock in some deep roadways of high stress and soft rock, and other roadways under complex conditions.As a new concept, synergistic anchorage applies synergistic principles to stability control of the surrounding rock. It offers a new perspective to researchers, provides a scientific guidance and theoretical basis to the study of engineering control mechanism in roadway and similar projects, and develops a reliable, applicable, and effective system of synergistic anchorage technology.更多还原