回采工作面顶板控制设计的方法与步骤

系统地介绍了工作面顶板控制设计的方法与步骤.

薄基岩下巷道掘进顶板管控技术研究

煤炭是我国的主要能源,是我国经济发展的基础产业。在煤矿开采的过程当中,为了保证煤矿开采的安全以及煤炭资源开发的质量,需要对煤矿掘进巷道技术和巷道顶板管理等一系列的技术进行研究,顶板事故在煤矿开采的过程中占有很大的比重,甚至会在掘进过程中造成冒顶事故。因此,只有在煤矿掘进过程中全面加强对顶板的控制和管理,才能保证安全掘进。本文结合实际薄基岩下巷道掘进对顶板管理的案例,主要分析薄基岩下巷道掘进顶板管控技术的应用。

哈拉沟煤矿特殊采掘条件顶板管控技术

为解决哈拉沟煤矿采掘工作面特殊条件顶板管控难题,分析了综采面各类顶板灾害发生的机理,并实施综合顶板管控技术,确保了综采面过特殊条件区域顶板安全;同时从设计源头着手,充分分析掘进地质条件,采取有效的掘进、支护手段,确保了掘进面过特殊条件区域顶板安全。结果表明:综采面过空巷老顶超前断裂,易发生滑落失稳,采取泵送支柱支护技术能够实现综采面安全过空巷群;综采面过沟存在过沟底薄基岩区域全厚切顶和上坡段切顶压架危险,通过实施井下提前疏放水、薄基岩注浆加固和危险区域预测等综合措施能够确保综采面安全过沟谷。通过对比断层上、下盘标高,采取钻探、巷探验证,优化了掘进过断层方案,实现了巷道最少化掘进;采取层间岩层加固、锚索穿层支护和架棚支护措施,为重叠巷道分叉区域下方巷道掘进顶板管控提供了保障。

长壁综采充填前顶板不可控下沉量研究

充填前顶板下沉量是引起充填开采地表沉陷的主要因素之一,受充填回采工序的影响,充填前顶板下沉量较常规回采工作面大且仍没有有效办法加以控制,此处将该下沉量定义为充填前顶板不可控下沉量;以邢台矿7608充填工作面为工程背景,对充填前顶板不可控下沉量进行研究,通过弹性地基梁理论对不可控下沉量影响因素进行定性研究;利用FLAC3D数值模拟和相似模拟试验对充填前顶板不可控下沉量的影响因素进行定量研究。结果表明:煤层埋深和顶板岩性对该下沉量影响较大,同时通过优化采高和控顶距及提高液压支架的初撑力和工作阻力可以缓减充填前顶板不可控下沉量。

大采高综采工作面沿空留巷工艺顶板管控技术分析

为研究沿空留巷工艺在大采高综采工作面顶板管控方面支护的可靠性,针对大柳塔煤矿52605综采工作面施工的大采高沿空留巷工程顶板管控方法和留巷施工区顶板支护技术机理进行了分析与总结,利用数值模拟软件对支护参数进行验证,结合工程现场上传的砼墙应力监测、尤洛卡应力监测、顶板离层和围岩移近量观测数据,论证了该工程支护方案的可行性,并且提出了针对该工程留巷段顶板管控的方案与措施,为近似采场条件和该盘区下一接续工作面沿空留巷顶板管控提供借鉴。

坚硬石灰岩顶板矿压规律研究及其控制方法

文章对凤矿一五二盘区首采面采场矿压监测数据及其显现形式进行了分析研究,在原有坚硬石灰岩顶板破断规律及控制技术基础上,通过采取相应顶板管控措施,为盘区后续工作面的顶板管理提供了一定的参考与指导依据。

画眉沟矿采场顶板管控技术措施

采场顶板的有效管理和控制,对于改善深井开采作业环境、避免发生顶板安全事故、提高生产效率具有重要意义。针对画眉沟矿的生产实际情况,提出了用锚杆+金属网加固顶板、合理确定矿房(柱)尺寸、利用压力拱原理控制顶板应力、及时检撬顶板、用废石充填采空区等顶板管控技术措施。该类措施的成功运用,该矿未发生冒顶事故及冒顶未遂事故,由于采空区被充填,陷落区被逐步压实,地压区段的岩体沉降速度大大减慢并趋于稳定,经GPS定位监测,地面未出现塌陷,地表民宅和工业建筑得到了有效保护。实践证明:锚杆+金属网支护、矿房矿柱的技术参数选择较合理,可供类似矿山参考。

厚层坚硬难冒顶板安全初放技术研究与实践

谢桥矿在8煤回采过程中遇厚层坚硬难冒顶板,对采面生产和安全带来极大威胁,通过回采实践,初步掌握了厚层坚硬难冒顶板初放期间安全管理技术,为今后安全高效的开采相邻阶段采面或相似地质条件采面提供了一定技术管理经验。

大采高短壁综采工作面矿压规律研究及顶板管理

在矿井厚煤层开采过程中,有时受条件限制需要布置短壁综采工作面,以提高矿井安全可靠度和煤炭资源采出率。大采高短壁综采工作面受煤层赋存条件、工作面布置、采高设计、生产组织等影响,采空区顶板不易垮落,容易出现采空区大面积悬顶,从而引发工作面漏风、低氧、有害气体超限、飓风冲击、设备损坏等灾害事故;另一方面,由于回采过程中矿压显现与传统的长壁综采工作面不同,因此单一的研究方法很难准确总结出矿压规律。为更好地指导安全生产,通过采取矿压数据统计分析、钻孔裂隙窥视、地表塌陷对比等综合分析方法,对大采高短壁综采工作面矿压显现规律开展研究,证实了大采高短壁综采工作面矿压显现不明显,生产过程中一般不会出现立柱安全阀开启、漏顶、煤壁片帮、巷道离层或变形等现象;得出了大采高短壁综采工作面基本顶周期断裂位置并未出现在煤壁前方,一般也不会出现在支架控顶范围,而是折断于支架切顶线后方采空区内的结论。针对工作面存在的大面积悬顶事故风险,提出了工作面两端头顶板退锚、三角区顶板高压水预裂、施工临时挡风墙、三角区顶板预裂爆破、安全生产标准化管理等顶板管控措施。实践证明,通过采取上述措施,大采高短壁综采工作面采空区大面积悬顶问题得以解决,采空区顶板能够及时垮落,支架后及三角区充填效果良好,有效避免了顶板灾害及次生、衍生事故的发生。

综采工作面破碎顶板管理技术及措施

介绍了开滦东欢坨9煤层的基本情况，结合3093综采工作面，对松软破碎煤层顶板频繁冒落的原因进行了分析，总结了在松软破碎煤层条件下开采过程中，过顶板破碎区顶板控制的技术与措施。

高瓦斯综放工作面末采阶段的瓦斯管控方法探究

对于末采阶段的高瓦斯综放工作面,在现场实际情况允许的情况下,通过改变工作面通风方式、堵塞采空区漏风通道、控制工作面顶板煤体、煤帮和工作面工程质量等途径,实现瓦斯的综合治理,为工作面正常回采并最终顺利形成撤架通道创造安全可靠的条件。结合成庄矿2317综放工作面末采阶段瓦斯治理情况进行具体探讨。

补连塔煤矿22310综采面回采经验分析

针对大采高综采工作面回采过程中顶板压力大、顶板控制难、出现底鼓难等一系列现场管理难题。以补连塔煤矿大采高综采工作面为例,介绍了7 m大采高综采工作面回采过程中支架工作阻力确定方法、顶板管控办法、末采贯通顶板控制。为类似地质条件的大采高综采工作面顶板管理提供一定的借鉴。

综采工作面初采阶段关键技术探讨

初采在综采工作面回采过程中出现的问题最多,其中,顶板是最主要的影响因素,出现的问题也最多。通过对初采历次出现的问题进行分析,找出了减少乃至消除影响的共性措施和办法,以降低综采工作面初次来压对工作面的破坏程度,为工作面快速、安全、高效地推进提供技术指导。

Review of roadway control in soft surrounding rock under dynamic pressure

The basic characteristics of the soft rock roadway under the dynamic pressure are analyzed. At the same time, the three fundamental approaches for controlling the surrounding rock are proposed, which are improving the surrounding rock strength, lowering the rock mass stress and selecting the reasonable supporting technology. The research results are elucidated, including the distribution of the surrounding rock plastic zone, the movement and damage of the surrounding rock under the dynamic pressure, controlling the floor heave through reinforcing the roadway walls and corners, the new route to develop the roadway metal supporting technique, the key theory and technique for the bolt supporting in the coal roadway, the performance and prospect of the ZKD high water content quick setting material, and so on. Finally, some personally views are put forward about the roadway metal supporting, bolt supporting, new material and the stress relief under the high stress condition.

Study on strata control by delay grouting in soft rock roadway

The properties of broken rock before and after grouting reinforcement are studied. Testing results show that grouting can raise the residual strength of broken rock, and the broken rockness by grouting can keep the steady supporting capacity within a relatively large deformation range. Revealing of the characteristics of stage deformation and damage process comes to the conclusion that the supporting of soft rock roadway should be analyzed in a dynamic view, and the grouting should be delayed at a proper occasion. Based on the above, the stepwise reinforcement technology characterized by immediate shotcreting, timely bolting and delay grouting is put forward and illustrated with a successful engineering practice.

A holistic examination of the load rating design of longwall shields after more than half a century of mechanised longwall mining

It is a commonly asked question:how big should the longwall shields be? The answer is a key aspect of a longwall mining feasibility study when the consequences of inadequately rated shields are considered.This paper addresses this question based on the measured nature of the loading environment in which shields are required to operate,the various geological and geometrical controls of that environment and the various links between their load rating,a range of other relevant shield design factors and the loss event they are required to prevent a major roof collapse on the longwall face.The paper concludes that despite the tremendous advances that have been made in shield design and load rating over the past50 years,the same drivers that caused longwall miners of the past to seek improved roof control on the longwall face via the use of ever-higher rated shields,are still as relevant today.However at the current time,the limits of the largest available longwall shields have yet to be tested,therefore industry focus for the foreseeable future should possibly be in achieving the maximum level of roof control on the face via their optimum operational use rather than considering further shield rating increases and incurring the inevitable downsides in terms of capital cost and shield weight.

Field investigation into directional hydraulic fracturing for hard roof in Tashan Coal Mine

t Research and development of safe and effective control technology of hard roof is an inevitable trend at present. Directional hydraulic fracturing technology is expected to become a safe and effective way to control and manage hard roof. In order to make hard roof fracture in a directional way, a hydraulic fracture field test has been conducted in the third panel district of Tashan Coal Mine in Datong. First, two hydraulic fracturing drilling holes and four observing drilling holes were arranged in the roof, followed by a wedge-shaped ring slot in each hydraulic fracturing drilling hole. The hydraulic fracturing holes were then sealed and, hydraulic fracturing was conducted. The results show that the hard roof is fractured directionally by the hydraulic fracturing function of the two fracturing drilling holes; the sudden drop, or the overall downward trend of hydraulic pressure from hydraulic monitoring is the proof that the rock in the hard roof has been fractured. The required hydraulic pressure to fracture the hard roof in Tashan coal mine, consisting of carboniferous sandstone layer, is 50.09 MPa, and the fracturing radius of a single drilling hole is not less than 10.5 m. The wedge-shaped ring slot made in the bottom of the hydraulic fracturing drilling hole plays a guiding role for crack propagation. After the hydraulic fracturing drill hole is cracked, the propagation of the resulting hydraulic crack, affected mainly by the regional stress field, will turn to other directions.

煤矿井下掘进工作面安全高效过断层方法

屯宝煤矿I0110502上顺槽掘进过程中遇7条断层。针对井下煤矿掘进过断层期间顶板管控的难题,对巷道施工工艺、支护方法进行优化,调整巷道坡度,加注加固材料,加密支护间距,增加U形钢支架补强支护。围岩变形监测数据表明,过断层期间顶板管控良好,巷道围岩稳定性高,未发生顶板事故,证明该方法有效。

Research into stope roof control of compound roof by solid backfilling mining

Based on the analysis of the failure characteristics and backfilling effect of the compound roof at 1801 backfilling workface in Taiyuan coal mine, China, we propose a method of controlling the pre- subsidence of a compound roof by using pre-stressed bolts to improve the backfilling ratio of the work- face so as to maintain the global stability of the stope roof. In addition, PHASE simulation software was employed to analyze the influence law of pre-stressing force, length, and interval on roof subsidence at the workface. On the basis of the numerical simulation results, a model for calculating the pre-stressing force and length of the bolts, the interval between the bolts, as well as roof subsidence at the workface, was established by using SPSS regression analysis software. Moreover, the research results were applied successfully to the 1801 filling workface. According to the monitoring data of roof closure, it was found that the final subsidence value for the goal roof was 350 mm and the filling ratio at the workface was 86%, which could fully meet the demand for safety production at the workface. The safe and effective control of the stope roof was therefore realized, which achieves the goal of safe and efficient backfilling mining under a compound roof.

Mechanism and practice of rock control in deep large span cut holes

Deep large span cut holes are difficult to stabilize. The 7801 cut hole in the Lu'an Wuyang Mine was used as this project's background. The main factors affecting large span cut hole stability are analyzed. Pre- stressed bolting theory was used to design a roof control method for a large span roadway. By reducing the span and applying equal strength coordinated supports the rock could be stabilized. The control prin- ciples and methods are given herein along with the analysis. A double micro arch cross section roadway is defined and its use in solving the current problem is described. Beam arch theory was used to build a model of the double micro arch cross section roadway. A support reverse force model for the arch foot intersection was also derived. A support method based upon reducing the width of the large span in the cut hole is presented. These results show that the reduced span of the roadway roof plus the use of cable anchors and single supports gives an effective way to control the large span cut hole. On site monitoring showed that the reduced span support from the double micro arch cross section roadway design had a significant effect. The roadway surface displacement was small and harmful deformation of the cut hole was effectively controlled. This will ensure its long term stability.