运输巷倾斜顶板用端头支架的研制

为了对大倾角工作面运输巷倾斜顶板进行有效支护,研制了一种新型运输巷倾斜顶板专用端头支架。支架顶梁能够随着巷道顶板倾斜角度变化而变化,对顶板进行有效支护;顶梁内的伸缩梁和底座防滑装置对第1架过渡支架能够进行有效的防倾倒和防滑控制;沿巷道方向,前、后两架互为支点,交替前移。

缓倾斜弹性薄板顶板力学模型分析

针对缓倾斜顶板稳定性分析问题,基于三维模型进一步分析在一定倾角以及受非均布荷载情况下顶板的破坏规律。根据弹性薄板小挠度理论对缓倾斜顶板建立不同边界条件下的薄板力学模型,分别对四边固支薄板、两边固支两边简支薄板以及四边简支薄板模型进行力学分析,运用伽辽金法计算各薄板力学模型的挠度公式,并求出相应弯矩以及应力解。运用MATLAB软件绘出工程实例的挠度曲线和弯矩曲线,分析得到顶板应力分布特征以及破断机理。结果表明,顶板形成“长边—短边—中部”的破坏机制,由整体破坏过程来看,也可看作顶板形成“O-X”型的破断模式,可为缓倾斜顶板支护以及顶板破断机理分析提供了理论依据。

煤巷倾斜层状顶板变形影响因素及变形规律

针对煤巷倾斜层状顶板的结构特点，建立煤巷倾斜顶板的简支梁力学模型，推导顶板挠曲线的计算公式和巷道顶板最大下沉位置。结果表明：倾斜层状顶板最大下沉位置不在巷道中心线上，而是向巷道底帮偏移；影响倾斜巷道顶板下沉曲线的因素主要有顶板岩层弹性模量、岩层厚度、顶板关键层位置、巷道宽度和顶板倾斜角度,其中弹性模量和岩层厚度仅影响顶板下沉量，但不影响顶板最大下沉位置，而关键层位置、巷道宽度和顶板倾斜角度对两者均产生影响；随着关键层与顶板距离的增大，最大下沉位置向巷道中心线移动；随着巷道宽度和顶板倾斜角度的增大，顶板最大下沉位置均向巷道底帮移动。现场工业性试验的实测结果较好地验证了理论推导的结果，因此，建议将顶板中部锚索位置整体向巷道底帮偏移10-30cm,以便更好实现顶板变形控制。

煤巷倾斜层状顶板变形失稳机理及支护技术

针对鹤壁矿区二1煤层回采巷道顶板变形严重支护困难,从倾斜岩层非对称作用、水平构造应力、煤帮软弱失稳、底鼓塑性流动诱发等方面分析揭示了顶板失稳力学机理。采用高预拉力、高刚度护表构件控制围岩浅部离层,利用围岩深部自承能力;锚索减跨强力悬吊,帮角弱化区补强支护整体促稳等支护对策,并提出了预拉力锚网索梁联合支护技术参数。结果表明:掘进期,新支护方案下的巷道顶板最大下沉量44 mm,降低75%;两帮移近量最大77 mm,减小60%;回采期,顶板最终下沉量138 mm,两帮移近量为179 mm,巷道支护状况有了明显改观。

倾斜空区顶板三铰拱轴曲线结构自稳分析

研究发现动采应力再分布使空区顶板在失稳前两拐角处形成塑性铰区,承载机构转为充分自稳的三铰拱形.针对这一特点,提出将空区顶板近似为半跨的三铰拱轴曲线结构,并建立以空区跨度L、拱失f、顶板岩层载荷q(x)为变量的力学模型,推导冒落线方程y(x)和拱轴压力N(x)方程,分析空区顶板的稳定性和冒落线形式,并计算空区的临界跨度和临界暴露面积.以排山楼金矿空区为例,利用模型得出活动延深方向临界跨度70 m,走向140 m,临界暴露面积7 693 m2.提出禁止间柱回采,及时充填空区的治理方法,保障井下安全.

倾斜复合型顶板综采工作面超前支护研究

在综采工作面回采过程中,两顺超前支护的顶板管理十分重要,它是保证回采工作顺利进行的最重要因素之一。而复合型顶板具有易离层、易折断、稳定性差、支护难度大的特点,在顶板安全管理上,是一个长期困扰综采两顺巷道维修工作的难题。大兴煤矿通过采取有力措施,及时、合理改变支护方式,达到了对顶板的有效控制,保证了安全生产和回采工作的顺利进行。

缓倾斜复合顶板综放开采顶板运动规律研究

采用理论分析和相似材料模拟实验方法,对缓倾斜复合顶板综放工作面的顶板运动规律进行了综合研究。理论计算周期来压步距37m,周期来压步距12m。相似材料模拟确定基本顶来压步距42m,周期来压步距10m^12m,研究确定的矿压参数与工作面实际矿压显现规律是一致的。确定的矿压显现规律指导工作面矿山压力控制,保证了工作面顶板的稳定。

南凹寺煤业顶板倾斜探水钻孔封孔技术优化

南凹寺煤业30407下顺槽掘进前期施工完成后的顶板倾斜探水钻孔,存在封孔效果差、钻孔易塌陷、水压大卸压困难等问题。结合矿区内同类型地质条件下水害治理经验,提出了顶板倾斜探水钻孔“两堵一注”配备自动卸压控水装置的封孔工艺,有效解决了原封孔工艺上存在的弊端,确保了探放水钻孔施工和放水作业的安全。

倾斜厚层坚硬顶板沿空留巷围岩控制研究

总结倾斜厚层坚硬顶板沿空留巷围岩控制规律,针对倾斜厚层坚硬顶板沿空留巷围岩控制技术难题,设计围岩支护方案:巷内围岩支护采用“锚杆+锚索”联合支护并设计三种支护方案、两侧煤帮加铺钢丝网,巷旁支护采用“预裂爆破切顶卸压+‘L’型护墙钢筋网+巷旁支护体”联合支护,超前加强支护在工作面前方10 m采用双排单体液压支柱、前方10~20 m采用单排单体液压支柱,滞后补强支护在工作面后方90 m范围内采用双排单体液压支柱并补打密集锚索。并采用FLAC 3D数值模拟对比围岩应力特征和围岩位移特征确定最优巷内围岩支护方案。

悬轨翼式液压锚杆钻车优化研究

为解决长城六矿大倾角倒梯形巷道倾斜顶板支护困难,掘进效率低下的问题,在研究其煤层地质条件及围岩情况的基础上,引入了悬轨翼式液压锚杆钻车,配合悬臂式掘进机进行掘进施工。并依据现场钻车的应用情况进行信息反馈,以数值模拟方式对钻车临时支护平台进行优化改进。现场应用表明:钻车行走于断面上部空间,与悬臂式掘进机错步施工,临时支护平台很好地契合倾斜顶板,能够完成特殊断面的支护作业;锚杆锚索施工效率提高60%以上,锚杆钻车巷道掘进支护月平均进尺达到350 m。临时支护平台优化改进后,钻车临时支护平台的承压效果更好,极大降低了结构发生应力集中现象的概率,关键部位的结构位移减少了63.72%,对特殊断面形式的支护装备应用及优化具有重要的参考意义。

特厚倾斜复合顶板巷道破坏特征与稳定性控制

大倾角特厚复合顶板巷道因其围岩原位强度低、层间黏结力弱,在复杂应力作用下巷道围岩具有非对称破坏特征。结合具体工程实例,采用相似模拟试验、FLAC3D数值模拟和工程测试等方法,分析不规则梯形与拱形巷道在常规对称支护和非对称强力支护条件下围岩应力、位移等变化规律,揭示特厚倾斜复合顶板巷道的非对称破坏机理。研究表明:受岩层赋存特征影响,巷道围岩结构和应力分布的非对称性是造成巷道非对称性破坏的根本原因;复合层状岩层结构面法向约束力减小与钝角部位应力集中直接导致弱面剪切滑移失稳;采用拱形巷道与非对称强力支护能有效改善围岩应力状态、减小围岩变形,提高巷道支护体系的平衡承载能力。

异型巷道立式导向杆机构超前支架设计研究

分析了我国煤矿目前对顶板倾斜工作面异型巷道支护的现状及其存在的问题,设计开发了适应顶板倾斜工作面的异型巷道超前支架,填补了国内外在该领域的空白,并在矿山应用,效果良好。

Analysis of stability of support and surrounding rock in mining top coa of inclined coal seam

The study analyzes the characteristics of roof movement in mining top coal of inclined coal seam,and establishes the mechanical model of support and surrounding-rock stability in inclined coal seam.Besides,this study carries out the numerical calculation and field observation of roof movement and support stability,and provides the critical control measures.The results show that the fracture firstly appears in middle-upper roof and extends upwards in top coal caving in inclined coal seam;regular and irregular caving zones appear in middle-upper stress concentration region,and the asymmetric caving arch is finally formed.Support load of middle-upper working face is larger than that of the middle-lower face;dynamic load coefficient of upper support is large,and the load on the front of support is larger than that on the rear of it,which leads to poor support stability.Stability of support and surrounding-rock system depends mainly on upper-support stability.

Underground pressure appearance laws analysis for fully mechanized top coal slice caving on high-dipping thick coal seams

Taking Adaohai Coal Mine as the example, underground pressure appearance laws of fully mechanized top coal slice caving on high-dipping and thick coal seams. Through site visit, theoretical analysis and discrete element calculation, the research shows that, as the mining deepens, underground stress of lower sublevels is more obvious and higher than that of upper sublevels and is higher in the air return roadway than that in the air intake roadway in the area that is near to the top coal. Because the top coal is thick and gangue is caved above the support, underground pressure to the working face is relatively gentle. Immediate roof will mainly fall down along the floor. Main roof and the rock bed above the main roof will move to the mined out area along the fault in the early stage and then fall down with the mined out area later. In addition, roof pressure mainly periodically appears in two directions along the trend and the dip.

Stability of roof structure and its control in steeply inclined coal seams

To improve the effectiveness of control of surrounding rock and the stability of supports on longwall topcoal caving faces in steeply inclined coal seams, the stability of the roof structure and hydraulic supports was studied with physical simulation and theoretical analysis. The results show that roof strata in the vicinity of the tail gate subside extensively with small cutting height, while roof subsidence near the main gate is relatively assuasive. With increase of the mining space, the caving angle of the roof strata above the main gate increases. The characteristics of the vertical and horizontal displacement of the roof strata demonstrate that caved blocks rotate around the lower hinged point of the roof structure, which may lead to sliding instability. Large dip angle of the coal seam makes sliding instability of the roof structure easier.A three-hinged arch can be easily formed above both the tail and main gates in steeply inclined coal seams. With the growth in the dip angle, subsidence of the arch foot formed above the main gate decreases significantly, which reduces the probability of the roof structure becoming unstable as a result of large deformation, while the potential of the roof structure's sliding instability above the tail gate increases dramatically.

倾斜煤层沿空异形巷道煤柱宽度与围岩控制研究

为了探究倾斜煤层沿空掘巷留窄煤柱的合理宽度,采用传统矿压"内外应力场"理论和偏应力第二不变量表征特性对不同宽度煤柱影响下巷道围岩破碎机理与控制展开研究。通过建立沿空斜顶巷道力学模型,推导出倾斜煤层"内应力场"影响范围为12.2～12.8 m。与水平煤层不同,倾斜煤层巷道顶板围岩在一定深度开始受到其相邻采空区应力影响,引起偏应力值再次攀升,计算应力波动值结合巷道围岩位移变化情况,最终确定合理窄煤柱宽度为10 m。异形巷道断面特征导致围岩应力分布和破碎呈现不对称性,继而提出顶板预应力锚杆+高强度单体锚索+桁架锚索支护耦合作用下的非对称围岩控制技术,最后经50 m试验段作为工程检验,成功应用于工程现场。

Study on stress distribution and failure criterion of the roof for the severely inclined coal seam under long wall working

By turning to the theory of elastic thin plates, a mechanical model of the main roof breaking for severely inclined seam under long wall working was esbalished, in which formulaes were deduced for the calculation of the stress distribution. When the main roof stress distribution was characterized, the failure form of the roof in the long wall coal seam under work was given with the failure criterion deduced. The deduced failure criterion was then applied to the No.3232（3） face of the Li- zuizi Coal Mine; the first pressure for the working face was accurately predicted. Results of the field application show that the main roof of the severely inclined coal seam under long wall working breaks in the O-X pattern, which is basically in accor- dance with the reality.