Deformation effect of lateral roof roadway in close coal seams after repeated mining

This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the roadway of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the proposed method was beneficial in field cases.

Roof filling control technology and application to mine roadway damage in small pit goaf

To recover coal resources that have been damaged by traditional mining methods and ensure stability of the lower roadway in a small pit goaf,the goaf area must be filled and reinforced.In this research,the 1202 working face of the Hanzui mine is considered as an example for classifying the roof of the mining tunnel under the small kiln destruction zone,the effect of the goaf on the roadway is determined based on the radio tunnel penetration method,a mechanical model to determine the roof filling control mechanism was established,and the duct foaming system and roof filling process were designed.The results show that the scope and degree of influence of the goaf on the mining lane are large,but safe tunneling can be ensured through the use of a steel shed and advanced grouting techniques.When the roof conditions are not similar,materials with different filling heights and filling strengths can be used to control the roof filling of the roadway.By combining field experience and laboratory tests,it was determined that a high-foaming material with a water-cement ratio of 1:0.6,a suitable high-foaming additive,and a water volume ratio of 1:30 is cost-efficient for filling and meets the filling strength requirements.Finally,the reliability of the proposed technology was verified by field experiments,which provide a reference for filling operations in similar mines.

复采条带煤柱沿空掘巷稳定性研究

详细分析了条带煤柱复采时沿空掘巷的支护特点。顶板锚杆对沿空掘巷的总体稳定性无法起到有效的控制作用,只有提高围岩的强度,发挥围岩的自承能力才能对巷道起到有效的支护作用。针对岱庄煤矿矿2351工作面的具体地质条件确定了具体的支护方式。通过对巷道的支护效果监测分析在该支护方式下,巷道两帮及顶板在巷道开挖初期变形明显,两帮变形尤其是非生产帮变形明显大于顶板变形;由于采空区上方顶板跨落倾斜作用于非生产帮外侧,非生产帮2.2 m处所受压力大于1.0 m处所受压力;巷道掘进完成以后变形和压力仍然有所增加,但最终趋于稳定。研究表明采用高强度左旋连续螺纹锚杆加低松弛预应力锚索的联合支护方式能够保证巷道两帮及顶板围岩的稳定性。

采空区复采巷道掘进施工方法

采空区复采巷道的掘进一般围岩较破碎,需要先把前探钢钎插入掘进工作面内,再进行装药、爆破等工作,确认安全后,铺设联顶网,使用液压支柱配合长木料将顶网顶起,然后移前探梁,放棚梁,再出煤(矸),栽棚腿,以此为一个巷道掘进循环。在掘进工程的探索中,发明了一种采空区复采破碎围岩掘进超前支护装置,保证了掘进工作面爆破掘进时顶板的完整性,缩短了采空区复采巷道掘进的时间。

煤矿掘进巷道顶板事故预防及断面优化设计

煤矿掘进巷道顶板事故是煤矿生产的主要灾害之一,分析了顶板事故的影响因素,并提出了断面优化和支护施工的方式,从而正确支护井巷、掘进巷道断面,预防顶板事故,保障煤矿工人的安全。

松软破碎煤层综采放顶煤回采巷道布置优化

通过数值模拟、理论分析及现场观测对五阳煤矿综采放顶煤7603工作面回采巷道的布置及快速掘进优化进行了研究,得出对于煤层厚而松软破碎的情况下,综采放顶煤开采回采巷道传统的沿底布置,顶煤不易管理,存在顶煤随掘随冒的现象,严重影响掘进效率,而采用沿顶掘进解决了随采随冒现象,基本实现了快速掘进,也为相同开采条件矿井回采巷道布置提供了参考。

峻德矿特厚煤层综放面顶板下斜钻孔防火实践

因无灌浆系统,选择在顶板巷打下斜防火注浆钻孔,合理布置钻孔位置,使采空区全面受浆,取得了较好效果。

残煤复采综放工作面液压支架选型研究

为对残煤复采综放工作面液压支架进行合理的选型,以晋煤仙泉煤矿2201残煤复采综放工作面为研究背景,采用现场地质资料调查、理论分析、数值模拟等方法,对该地质条件下的工作面液压支架进行合理的选型。结果表明:复采工作面过空巷时形成的基本顶长关键块长度为空巷宽度、煤柱失稳极限宽度、基本顶周期来压步距之和,并通过分析最终确定的支架合理工作阻力为9 532 k N、初撑力为7 144 k N(31.5 MPa)、中心距为1 750 mm、支架高度为2.5~4.2m。通过研究结果结合复采工作面现场情况,选定ZFY10200/25/42两柱掩护式放顶煤液压支架为合理架型。

重复采动下顶板含水巷道顶底板变形机理及控制

针对内蒙古巴彦高勒煤矿重复采动下影响顶板含水层回风巷道顶底板变形较大的问题,采用现场实测及理论分析方法,通过分析巷道围岩松动圈的成因及影响因素,对巷道顶底板变形较大的机理及控制措施进行了研究。结果表明:初次采动影响时,支承压力主要作用于护巷煤柱,巷道顶板松动圈范围较小,护巷煤柱应力在巷道底板释放导致局部的底鼓现象,但巷道顶底板整体变形不明显;重复采动影响时,巷道顶板承受支承压力较大、两帮应力在底板释放,顶底板松动圈范围扩大,顶板松动圈发育至含水层后,顶板水弱化顶底板煤岩体强度,导致顶底板松动圈进一步增大,巷道顶底板变形较大;提出了相应的巷道变形控制措施,在现场应用效果显著。