深部开采软岩巷道耦合支护数值模拟研究

通过对深部开采软岩巷道的变形破坏机理的研究发现，巷道变形破坏主要是由于支护体力学特性与围岩力学特性在强度、刚度以及结构上出现不耦合所造成的；且变形首先从关键部位开始，进而导致整个支护系统的失稳．因此，要保证深部软岩巷道围岩的稳定性．必须实现支护体与围岩的耦合．数值模拟研究表明，当锚杆与围岩在刚度上实现耦合时，能最大限度地发挥锚杆对围岩的加固作用；当锚网与围岩在强度上实现耦合时，将会使围岩的应力场和位移场趋于均匀化；当锚索与围岩在结构上耦合时，可以充分利用深部围岩强度来实现对浅部围岩的支护．实践证明，软岩巷道耦合支护可以有效解决深部开采软岩巷道支护问题。     

三软煤层巷道支护方式及围岩控制效果分析

在分析三软煤层极不稳定煤巷矿压特点基础上，研制了适应两帮大变形的可缩性工字钢支架、适应两帮及顶底严重变形特别是底鼓的U29可缩性环形支架，设计了锚架注联合支护的参数与工艺，并在同一采区先后进行了工业性试验．采用数值模拟方法研究了三软条件下锚梁网索支护不同参数选取、不同布置形式对围岩变形的控制效果，优选了支护参数并进行了现场试验，比较试验结果，表明极不稳定煤巷围岩变形主要特点是强烈和持久的两帮移近及底鼓，锚梁网索支护是控制围岩大变形的有效方法，其技术关键是提高锚杆初锚力、布置底角锚杆及顶角锚索．     

深井软岩巷道底板卸压钢丝绳网锚注支护技术研究

针对平顶山天安煤业股份有限公司一矿深井软岩回风上山巷道工程地质条件和围岩变形特征,采用数值计算方法,研究了底板卸压槽卸压前后巷道围岩应力场、塑性区的变化规律,分析了底板卸压槽卸压机理,提出了钢丝绳网锚注支护技术,并进行了工业性试验。研究结果表明:(1)巷道底板开掘卸压槽卸压后,底板围岩垂直应力和水平应力的高应力区及其峰值应力均向底板深部转移。卸压后底板同一深度的围岩应力均小于卸压前的围岩应力;卸压后巷道顶底板和两帮围岩的塑性区范围均增大,底板卸压效果明显。(2)深井巷道围岩的破碎区和部分塑性区是支护的重点。回风上山巷道采取开挖底板卸压槽、钢丝绳网锚杆支护和围岩注浆加固等支护措施后,在围岩中形成了锚注体支护圈,提高了围岩的强度和自身承载能力。巷道围岩经历加速变形阶段、减速变形阶段和稳定变形阶段后,一直处于稳定变形状态。卸压槽+钢丝绳网锚注支护在回风上山巷道的支护试验取得成功,可为深井软岩巷道支护提供参考依据。     

煤巷锚网索支护矿压显现规律数值模拟研究

本文结合观台矿实际情况,采用数值模拟方法对煤巷锚网索支护进行分析研究,得出了不同支护参数条件下巷道围岩变形规律,以及高水平应力是导致巷道加剧变形直至破坏的主要原因,既验证了支护参数合理性,又对支护效果进行预测,为优化支护参数提供理论依据.     

深部回采巷道支护参数的正交数值模拟

平顶山矿区深部主采煤层回采巷道矿压显现强烈,普通锚网支护难以适应深部开采的要求,高强度、高刚度、高预紧力的强力支护是控制深部围岩变形的有效途径.采用正交数值方法对平顶山矿区主采煤层回采巷道的支护参数进行了模拟分析,确定了影响围岩变形主次因素.应用多元回归分析法,拟合了巷道断面收敛系数与综合岩体强度、顶板锚索根数、锚杆预紧力、垂直应力和动载系数的关系式,对平煤股份十一矿高强锚网索支护的丁5-6-26071风巷断面收敛变形进行了预测,与现场矿压测试结果基本吻合.     

深部软岩巷道围岩变形分析与控制

针对某深部软岩巷道支护困难问题,首先对围岩进行力学性能试验,然后利用有限元分析方法,在基于不同埋深软岩巷道围岩变形特征研究的基础上,从巷道开挖和围岩支护两方面对深部高地应力软岩巷道围岩变形与控制进行深入研究.结果表明:随软岩巷道埋深增大,巷道围岩变形呈线性增大趋势;在深部高地应力下掘进巷道时,全断面开挖法围岩变形最大,台阶法次之,CD法最小;支护时采用柔性与刚性联合支护,围岩变形最小.联合支护技术能充分释放软岩巷道围岩变形能,发挥围岩自承能力并与支护体系共同作用,可以有效控制深部软岩巷道围岩变形,从而保证深部软岩巷道围岩的稳定性.     

软煤层巷道支护数值模拟研究

针对新义煤矿11011工作面回采巷道煤层松软、围岩变形大、现有微拱工字钢支护难以满足生产安全需要的问题,利用FLAC数值模拟软件分别对微拱工字钢和外扎腿U型钢支护下的巷道位移矢量特征、应力特征及塑性区范围进行了分析．结果表明,外扎腿u型钢支护,能有效地改善围岩的应力状态和控制围岩的变形量,适合该矿软煤层特征;通过对12011皮带运输巷进行的工业性试验的实测变形数据分析表明,外扎腿u型钢支护,降低了顶板与两帮收敛速度与位移,提高了软岩巷道围岩强度和自承能力,维护了巷道围岩的稳定性,支护效果良好,能满足新义煤矿安全生产的要求,可为类似条件下的巷道支护提供参考．     

潘三V类较软围岩巷道,交岔点锚喷网支护试验研究

用松动圈支护理论确定的锚喷网支护参数、施工工艺，通过在淮南潘三矿较软围岩巷道、交岔点软岩中进行工业试验研究，表明合理、安全可靠，提高了施工速度，降低了支护成本．该支护设计方法和施工工艺，在同类围岩中有推广价值     

大跨度切巷锚网索联合支护技术的应用研究

根据黄沙矿2147采煤工作面地质条件,通过理论计算,设计2147采煤工作面切巷的锚网索支护参数,并提出具体的施工工艺,为切巷施工提供了技术依据.切巷的支护效果观测表明,切巷的表面位移量、顶板离层量及锚杆锚固力均控制在切巷围岩变形允许的范围内,切巷锚网索支护效果较好,满足了切巷的服务要求.     

千米深井软岩巷道破坏机理及支护技术研究

基于矿井开采逐渐向深部发展,巷道围岩呈现高地压、大变形、难支护的特点,常规锚网支护已难以控制巷道围岩变形的情况.通过对华丰煤矿-1?100水平巷道破坏机理的研究,提出了采用马蹄形巷道支护断面和全封闭支护的理念,加强底板承载能力和巷道抗蠕变能力;根据千米深井巷道围岩流变特性,研究得出了围岩地压得到合理释放趋于稳定时进行永久支护的时机和距离,并在永久支护中实施锚注加固,使松散破碎岩块胶结成整体提高了围岩的内聚力和内摩擦角,使围岩由“软”变“硬”,使无支护作用的围岩体变为支护结构,同时锚注锚杆成为全长锚固锚杆,加强了围岩的加固效果,达到安全永久支护巷道的目的.     

Support technology for mine roadways in extreme weakly cemented strata and its application简

For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, I-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.     

Influence of dynamic pressure on deep underground soft rock roadway support and its application

Due to high ground stress and mining disturbance, the deformation and failure of deep soft rock roadway is serious, and invalidation of the anchor net-anchor cable supporting structure occurs. The failure characteristics of roadways revealed with the help of the ground pressure monitoring. Theoretical analysis was adopted to analyze the influence of mining disturbance on stress distribution in surrounding rock,and the change of stress was also calculated. Considering the change of stress in surrounding rock of bottom extraction roadway, the displacement, plastic zone and distribution law of principal stress difference under different support schemes were studied by means of FLAC3D. The supporting scheme of U-shaped steel was proposed for bottom extraction roadway that underwent mining disturbance. We carried out a similarity model test to verify the effect of support in dynamic pressure. Monitoring results demonstrated the change rules of deformation and stress of surrounding rock in different supporting schemes. The supporting scheme of U-shaped steel had an effective control on deformation of surrounding rock. The scheme was successfully applied in underground engineering practice, and achieved good technical and economic benefits.     

跨采软岩巷道锚注加固技术的实验研究

针对鲍店煤化北翼采区受放顶煤工作面跨采影响的下部主要岩石集中巷,对巷道采用不同支护形式的支护效果进行了相似模拟试验研究,得到了受跨采影响的软岩巷道在不同支护条件下的变形特征,为同类软岩巷道支护提供了科学的依据。     

支护阻力对不同岩性围岩变形的控制作用

在理论分析和数值计算的基础上,研究了不同岩性条件下支护阻力对围岩变形的作用和机理。阐述了硬岩巷道中支护要是控制塑性区的范围,软岩道中支护阻力提供围压,影响周力岩体的软化笥,遏制围岩破碎区的发展,从而控制围岩的变形。结果表明,岩性质越差,支护阻力控制围岩变形的作用越大,巷道位移量与支护阻力呈负指数函数关系。     

Principle and practice of coupling support of double yielding shell of soft rock roadway under high stress

In order to ensure the safety and stability of the soft rock roadway under high stress, based on the characteristics of the surrounding rock deformation and failure, this paper presented the support technology “coupling support of double yielding shell”, then gave the design method of inner and outer shells and analyzed the principle and requirements of the support technology by taking the −850 m east belt roadway of Qujiang coal mine as the background. The field application results show that the support technology can control the soft rock roadway deformation better under high stress. The displacement between roadway sides was 851 mm, the displacement of the roof was 430 mm, and the displacement of the floor was 510 mm.     

软岩巷道支护荷载的确定方法

通过分析巷道围岩与支护的相互作用原理 ,得出了软岩巷道失稳的原因是由于围岩自承力与支护力不足的结果 .认为一个优化的软岩巷道支护设计应在确保支护稳定的前提下 ,最大限度地释放围岩的能量 ,使以变形形式转化的工程力达到最大 ,同时最大限度地发挥围岩的自承能力 ,使工程支护力达到最小 ,而其关键是确定变形能释放时间和最佳支护时间 .软岩巷道开挖后 ,通常在巷道周围形成塑性软化区和塑性流动区 ,实施支护力就是要控制塑性流动区的范围与发展 ,达到最佳支护时间时的支护荷载为最小支护荷载 ,可以通过塑性软化区和塑性流动区内岩石的重力求得     

巷道围岩强度弱化规律及其应用

认为软岩巷道稳定性应采用动态支护的观点分析．用巷道周边位移表达的损伤因子来描述围岩阶段性变形特征及破坏过程,分析与之对应的围岩强度弱化规律,在此基础上提出了喷锚注分阶段加固技术,并对合理滞后注浆时间的确定进行了研究．最后,介绍了一个应用实例     

Deformation characteristics of surrounding rock of broken and soft rock roadway

A similar material model and a numerical simulation were constructed and are described herein. The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models. The deformation of the roof and floor, the relative deformation of the two sides and the deformation of the deep surrounding rock are predicted using the model. Measurements in a working mine are compared to the results of the models. The results show that the surrounding rock shows clear rheological features under high stress conditions. Deformation is unequally distributed across the whole section. The surrounding rock exhibited three deformation stages: displacement caused by stress concentration, rheological displacement after the digging effects had stabilized and displacement caused by supporting pressure of the roadway. Floor heave was serious, accounting for 65% of the total deformation of the roof and floor. Floor heave is the main reason for failure of the surrounding rock. The reasons for deformation of the surrounding rock are discussed based on the similar material and numerical simulations.     

Bolt-grouting combined support technology in deep soft rock roadway

Analyzing the mineral composition, mechanical properties and ground stress testing in surrounding rock,the study investigated the failure mechanism of deep soft rock roadway with high stress. The boltgrouting combined support system was proposed to prevent such failures. By means of FLAC3D numerical simulation and similar material simulation, the feasibility of the support design and the effectiveness of support parameters were discussed. According to the monitoring the surface and deep displacement in surrounding rock as well as bolt axial load, this paper analyzed the deformation of surrounding rock and the stress condition of the support structure. The monitor results were used to optimize the proposed support scheme. The results of field monitors demonstrate that the bolt-grouting combined support technology could improve the surround rock strength and bearing capacity of support structure, which controlled the great deformation failure and rheological property effectively in deep soft rock roadway with high stress. As a result, the long term stability and safety are guaranteed.     

Wide pillar roadway retained in the deep high gas coal seam

According to the geological and mining conditions of deep high gas coal seam, this paper established the mechanical model of stope surrounding rock, and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar. The research determined the arrangement mode that adjacent working faces retain wide pillar, and the reasonable support method of roadway that the combined support of roof and grouting combined together. The reasonable time of reinforced roadway was determined. Through analyzing the mechanical model of the ways of roadway supporting, this research drew the conclusions as follows: the combined support of roof and working slope improved the support strength and range of surrounding rock, optimized the support by adjusting the angle of anchor, and reached the support requirements by using cement grouting in working slope and chemical grout in roof. The technology was applied in 15104 working face of Baoan Mine, and obtained good results.