围岩-充填体组合承载宏细观损伤演化机理

充填体与围岩共同承载地应力,揭示其组合体宏细观损伤演化机理有助于完善充填体与围岩相互作用理论和优化充填体的配比和强度设计.开展不同灰砂比的围岩-充填体组合体单轴压缩试验和数值模拟,分析宏观下应力-应变曲线、力学参数及破坏模式,细观下裂纹扩展、能量变化及损伤演化规律.结果表明：灰砂比越高,组合体的峰值强度和弹性模量越大,峰值应变越小;组合体发生张拉剪切混合式破坏,低灰砂比时接触界面产生断裂破坏,高灰砂比时分层界面产生宏观裂隙;峰前阶段,接触界面和分层界面等薄弱部分先出现微裂纹,组合体以弹性应变能的转化为主,伴随小幅度能量损耗,损伤程度较低;峰后阶段,组合体耗散能急速增长并超过弹性应变能,内部损伤程度加速恶化.围岩内部裂纹数量大幅增加并迅速扩展贯通,率先出现宏观断裂面,充填体内部裂纹汇聚合并于分层界面,在高灰砂比时发挥良好的协同支护作用.     

pH值对高水固结充填材料凝结性能的影响机理

针对高水固结充填材料的凝性能随原材料的来源及直体配比不同而不同的问题，进行了高水材料的凝结时间与pＨ值的关系的实验；根据溶液中电解质的电离理论和热力学基本原理， 分析了高水材料浆液中形成钙矾石的各种离子开矿及其匹配关系，结果表明，高水材料浆液在pＨ〉１１时能凝结，pＨ约为１２时凝结时间最快（约２０ｍｉｎ）；在pＨ〉１１时， 高水材料泺注保Ｃａ（ＯＨ）２ａｑ，ＳＯ４ａｑ＾２－和Ａ１（ＯＨ）４ａｑ＾－的离子     

壁后充填体刚度对支架与围岩的作用分析

通过建立的力学模型分析了壁后充填体刚度对围岩和支架压力与位移的影响，提出了发迹充填体刚度的措施。     

固体充填体压实特征下岩层移动规律研究

基于充填材料压实特性试验,结合具体工程实例,推导出充填体弹性模量与垂直应变之间的关系,利用FLAC3D软件内置FISH语言,编制相应的充填体非线性压实程序,准确地模拟矸石充填采空区后上覆岩层移动规律.研究结果表明:充填采煤工作面顶板下沉量随着工作面的推进而逐渐增大,整体以缓慢弯曲下沉为主,没有出现激增的现象;超前支撑应力分布与垮落法开采相似,其超前支承应力峰值及影响范围均要比垮落法开采低;矸石充填体内部应力呈现"拱形"分布,随着工作面的推进,矸石充填体内部应力逐步升高,增幅逐渐减小.现场实测数据与数值模拟结果基本吻合,验证了研究成果的科学性.     

巷道围岩应力分布影响因素的研究

通过有限元计算和光弹模拟方法对影响巷道自稳结构形状的因素进行了探讨，分析了埋深，侧压秒数，巷道形状及裂隙等因素的变化对集中应力圈的作用，为合理选择巷道支护手段提供依据。     

地震对隧道围岩稳定性影响的数值模拟分析

利用ANSYS软件的谱分析，研究了地震对隧道围岩稳定性的影响规律，得出在不同岩性、跨度、地震波的类型情况下地震作用对隧道围岩产生拉应力和位移的特征，指出围岩的位移差异是破坏衬砌的主要原因，提出隧道支护应注意的问题，定量解释了大量调查资料中地震破坏隧道现象的成因。     

沿空留巷巷旁充填体宽度计算与分析

采用沿空留巷技术是目前解决高瓦斯深井开采难题的关键技术,而充填体是沿空留巷围岩结构的一个重要组成部分,其稳定特性直接影响着巷道整体的稳定性,关系高瓦斯深井开采的成功与否。因此,确定合理的巷旁充填体宽度也成为沿空留巷成功的关键因素之一。本文以谢桥煤矿11426工作面沿空留巷为工程背景,采用理论计算和数值模拟相结合的方法分析了巷旁充填体宽度对巷道围岩受力规律的影响,为今后类似工程提供技术依据。     

尾砂胶结充填体与岩体耦合作用机理研究

充填法开采被广泛应用于隐患资源2次开采中,研究充填体与岩体耦合作用机理,对充分利用矿产资源、保护地表建筑物、延长矿山服务年限等方面具有十分积极的作用.以程潮铁矿西区选厂下遗留矿柱2次开采为研究背景,通过对尾砂胶结充填体的无侧限单轴抗压正交力学试验,得到了不同灰砂比、不同浓度、不同龄期参数与充填体单轴抗压强度的曲线关系和多参数线性回归方程式,同时分析了影响充填体抗压强度的主次因素.最终依据充填体与岩体能量匹配原则,通过数值模拟并充分考虑回采中爆破震动对采场稳定性的影响,得出最优充填方案.     

壁后充填对提高巷道支护阻力的研究

支护阻力和可缩量是巷道支架的主要参数，高阻和可缩是确保软岩巷道稳定性的关键．支架的实际工作阻力经常远低于理论承载能力，主要原因往往是支架与围岩之间存在空穴、支架受力条件恶化等严重抑制着巷道支架支承能力的发挥．实施支架壁后充填，使围岩－充填体－支架结构三者形成共同的力学承载体系，可大幅度提高支架的工作阻力，有效地控制围岩的强烈变形，这是改进软岩巷道支护的重大措施．     

复杂条件下巷道围岩破坏机理及支护方案研究

从许厂煤矿复杂的地质构造入手,分析了复杂地质构造所引起的高应力特征,并结合围岩物理力学特性对巷道围岩变形破坏特点及破坏机理进行了分析,提出了复杂地质构造及高应力条件下软岩巷道的安全支护技术措施.该结果对同类型工程的设计与施工具有重要的参考价值.     

Temperature field distribution of burnt surrounding rock in UCG stope

In order to study temperature field distribution in burnt surrounding rock and to determine ranges of burnt surrounding rock, coal-wall coking cycle and heat influence in the underground coal gasification (UCG) stope, based on the Laplace transform and inversion formula, we studied the temperature analytical solution of one-dimensional unsteady heat conduction for multi-layer overlying strata under the first and the forth kinds of boundary conditions, and we also carried out a numerical simulation of two-dimensional unsteady heat conduction by the COMSOL multiphysics. The results show that when the boundary temperature of surrounding rock has a linear decrease because of a directional movement of heat source in the UCG flame working face, the temperature in surrounding rock increases first and then decreases with time, the peak of temperature curve decreases gradually and its position moves inside surrounding rock from the boundary. In the surrounding rock of UCG stope, there is an envelope curve of temperature curve clusters. We analyzed the influence of thermophysical parameters on envelope curves and put forward to take envelope curve as the calculation basis for ranges of burnt surrounding rock, coal-wall coking cycle and heat influence. Finally, the concrete numerical values are given by determining those judgement standards and temperature thresholds, which basically tally with the field geophysical prospecting results.     

破碎围岩巷道支护技术研究及工程应用

以平煤六矿新建斜井巷道穿越采空区为工程背景,采用数值计算分析、现场监测等方法研究了采空区覆岩破断及其矿压显现特征。针对斜井穿越采空区段围岩破碎的特点,提出了金属网+全断面U型钢+反底拱连锁梁+浇筑混凝土+壁后注浆的支护方案,其通过"双壳支护"形成的内外承载结构能在很大程度上提高采空区破碎岩体的整体性。现场监测表明:斜井穿越采空区段巷道两帮的移近量为26 mm,顶底板移近量为47 mm,达到了有效控制巷道围岩变形的目的。     

直墙拱形巷道围岩应力场分析

为得出直墙拱形巷道围岩应力分布规律,应用复变函数弹性理论推导了直墙拱形巷道围岩应力分布的解析表达式。对直墙拱形巷道边界的围岩应力和巷道水平线方向的围岩应力分布规律进行分析,并考虑直墙拱形巷道断面高宽比和侧压系数对其影响规律。研究表明：在不同巷道断面高宽比、侧压系数下,直墙拱形巷道围岩应力集中区域主要集中在直墙底部底角处、拱形顶板中点附近和底板中部3个位置。不同巷道断面高宽比下,直墙拱形巷道沿水平线的应力分布规律基本相同。侧压系数大于1时,采用巷道断面高宽比小于1较有利于巷道稳定;侧压系数小于等于1时,采用巷道断面高宽比大于1较有利于巷道稳定。     

Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.     

小净距隧道围岩稳定性的影响因素

近年来市政隧道工程蓬勃发展,许多城市公路隧道受建筑、管线等因素的限制,并为节约用地、缩短工期等目的,大多被设计成小净距隧道.小净距隧道在施工过程中与分离式隧道最显著的区别是中隔岩柱受力状态复杂、稳定性难以控制.通过理论推导,对浅埋超小净距隧道土质中隔岩柱的失稳机理进行系统研究,基于小净距隧道中隔岩柱承载模型确定中隔岩柱...     

孤岛工作面围岩支承压力分析与沿空掘巷支护参数优化

为研究孤岛工作面围岩支承压力特征与沿空掘巷支护参数优化,建立了三维数值模型,制定了相应的试验方案,研究了孤岛工作面沿空掘巷支护参数变化和围岩控制效果之间的相互关系,支护系统整体的协调性,并确定了最优支护方案.研究结果显示:随着锚杆长度增加,形成的组合梁厚度加大,孤岛工作面沿空掘巷的顶板岩层内的压应力增加,拉应力降低,减小锚杆的间排对于巷道有明显的支护效果,但锚杆长度和间排距均存在最优值;锚索长度对孤岛工作面沿空掘巷顶板内的压应力没有作用,而巷道两帮围岩水平方向的拉应力升高;支护系统最大应力随着锚索间排距的增加,而支护系统的单根锚索应力降低.现场实测验证了围岩控制效果.     

隧洞掘进机开挖的围岩-支护系统联合承载数值分析

对隧洞掘进机(TBM)开挖过程围岩-支护的联合承载特性进行了数值分析.首先详细分析了在TBM掘进时,围岩和支护的相互作用过程和各种荷载的属性.然后,提出了TBM施工围岩稳定和支护受力的计算方法,主要考虑了施工作用力、开挖荷载和外水压力荷载.提出了确定TBM施工过程中围岩单独承担开挖荷载比例的计算方法.最后结合某大型供水工程,采用上述方法分析了TBM掘进段II—V类围岩稳定和支护受力特性.计算结果既符合一般规律,也提供了定量评估围岩承载能力的方法,能够充分反应不同岩性下围岩-支护系统的联合承载特性,并从数值分析角度论证了衬砌设计的合理性.     

隐伏溶洞对隧道围岩稳定性影响规律及处治技术

以鄂西山区隧道工程实例为依托,在溶洞调查与统计分析的基础上,从岩溶的溶洞体积、形态特征、溶腔充填物特征以及涌水通道类型等方面,对鄂西山区岩溶进行分类,得到鄂西山区岩溶发育特征,即溶腔体积不等、形态多样、溶腔充填物种类多、涌水通道复杂。采用数值模拟方法,分析不同位置的隐伏溶洞对隧道围岩的应力场、位移场影响情况,得出随隐伏岩溶位置变化,围岩应力分布有所不同;溶洞位置由隧道顶部向隧道底部变化过程中,隧道顶部围岩最大沉降由大到小依次为拱肩延长线、边墙一侧、拱脚延长线、拱顶上方、底板下方;随着溶洞位置的降低,隧道拱顶围岩水平最大收敛值由大到小依次为拱肩延长线、拱顶上方、边墙一侧、底板下方、拱脚延长线;随着溶洞位置的降低,隧道周边围岩沉降量由大到小均为拱顶、拱腰、拱脚、底板。基于岩溶类型特征、数值模拟围岩应力场、位移变化情况结果,提出岩溶区隧道揭露溶洞处治原则。以花果山隧道为例,开展溶洞处治原则与方法应用,提出针对性的处治方案。     

Rock-breaking mechanism and experimental analysis of confined blasting of borehole surrounding rock

The rock-breaking mechanism and effect of confined blasting were analysed by blasting and impact dynamic mechanics, fluid dynamic mechanics, fracture mechanics as well as blasting experiment. The results showed that the fracturing of surrounding rock in confined blasting condition is the result of coaction of rock pre-cracking by shock wave and stress wave and the continuing expanding crackenhancement of confined medium, and the model of crack development of borehole surrounding rock in confined blasting condition was established. This study acquired the damage range of surrounding rock under the action of shock wave and stress wave, as well as the crack development characteristics of surrounding rock after the wedge-in confined medium into the crack space. Deep-hole confined blasting experiment on large rock showed that the high-efficient utilisation of in-hole explosive was achieved and the safety of rock blasting operation was ensured. Safe static rock-breaking under the action of high-efficient explosive blasting was achieved as well as the unification of super dynamic load of explosive blasting and static rock-breaking of water medium.