WO2019109700A1 - 基于顶板稳定性的煤巷强顶护帮锚杆支护方法 - Google Patents

基于顶板稳定性的煤巷强顶护帮锚杆支护方法 Download PDF

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WO2019109700A1
WO2019109700A1 PCT/CN2018/105350 CN2018105350W WO2019109700A1 WO 2019109700 A1 WO2019109700 A1 WO 2019109700A1 CN 2018105350 W CN2018105350 W CN 2018105350W WO 2019109700 A1 WO2019109700 A1 WO 2019109700A1
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roof
rock
bolt
anchor
coal
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PCT/CN2018/105350
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French (fr)
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张农
谢正正
伍业伟
韩昌良
姚文浩
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中国矿业大学
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Publication of WO2019109700A1 publication Critical patent/WO2019109700A1/zh

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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D20/00—Setting anchoring-bolts
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/24—Earth materials

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  • the invention relates to a coal roadway support technology, in particular to a coal roadway strong roof protection bolt support method based on roof stability.
  • coal mining technology has basically achieved modernization and mechanization.
  • the excavation process only coal, coal and coal transportation have been mechanized, and the support technology still relies on human tactics.
  • a large number of roadways need to be excavated in the underground.
  • the total length of newly-built roadway in state-owned large and medium-sized coal mines is about 8,000 km per year, and more than 80% of them are excavated in coal seams. Therefore, the speed of coal roadway driving directly affects mine mining succession.
  • the object of the present invention is to overcome the deficiencies in the prior art, and to provide a coal road strong roof protection bolt support method based on roof stability.
  • the roof roof stability support bolt support method of the roof stability comprises the following steps: dividing the roadway roof into different regions, drilling cores in each region, and analyzing each region. Core information to obtain rock integrity in all areas of the roof;
  • the core integrity of the detected area exceeds the preset value, it is judged that the rock formation in this area is a relatively complete rock layer or a complete rock layer, and the core of the area is subjected to uniaxial compression test, and the test results of each area are analyzed to determine the rock of each area of the roof.
  • Body mass index when the obtained regional rock mass quality index is greater than the preset value, then the roof plate is evenly and vertically arranged in the area, and multiple anchor bolts or anchor cables are single strengthened support, and the vertical direction is uniform in the corresponding range of the coal seams on both sides. Arrange multiple anchors.
  • the roof plate is evenly and vertically arranged with 4-6 anchor bolts or anchor cable single strengthening support in the roadway. 3 to 4 anchor rods are evenly arranged vertically in the corresponding range on both sides of the coal.
  • the tensile strength of the roof bolt or anchor cable exceeds 1600 MPa, and the length of the bolt is 3.5 m to 5.0 m; the tensile strength of the gang bolt exceeds 300 MPa, and the length of the bolt is 1.2 m to 2.0 m.
  • the roof bolt or anchor cable needs to be vertically arranged, and the allowable error cannot exceed 3°; the gang bolts need to be vertically arranged, and the allowable error cannot exceed 5°.
  • the bolt support row spacing is 1.5m ⁇ 2.0m.
  • the top anchor or anchor cable pre-tightening force is 180kN-250kN; the gang bolt pre-tightening force is 60kN-100kN.
  • the traditional support row spacing ⁇ 1m directly increased to the row spacing of 1.5m or more, greatly improved the bolt support row spacing, saving the support time, and significantly improving the coal roadway excavation
  • the speed and the effect of the roadway control are greatly improved.
  • the construction process of the tunneling is simplified, and the tunneling speed is further improved.
  • FIG. 1 is a schematic view showing a form of support and deformation of a roadway in the prior art
  • FIG. 2 is a schematic diagram of a coal roof strong roof protection bolt support method and a roadway deformation diagram based on roof stability according to the present invention.
  • the method for supporting the bolting method of the coal roof strong roof protection of the present invention is as follows: the coal roof panel 2 is divided into different regions, and the worker drills the top plate of each region on the bottom plate 4 Core, analyzing the core information of the top plate 2 of each region, thereby obtaining the rock mass integrity of the roof 2 of each region;
  • the core integrity of the detected area exceeds the preset value, it is judged that the rock formation in this area is a relatively complete rock layer or a complete rock layer, and the core of the area is subjected to uniaxial compression test, and the test results of each area are analyzed to determine the area of the top plate 2
  • the rock mass quality index when the obtained rock mass quality index is greater than the preset value, the top plate 2 is evenly arranged vertically in the area, and multiple anchor bolts or anchor cables 6 are single strengthened support, and correspondingly on both sides of the coal gang 3 A plurality of anchors 7 are evenly arranged vertically in the range.
  • the rock mass quality index of the top plate 2 is BQ>451
  • the roof plate 2 is evenly arranged vertically with a plurality of anchor rods or a single reinforcing support of the anchor cable 6
  • a plurality of anchor rods 7 are evenly arranged vertically in the corresponding range of the coal gangs 3 on both sides, and 3 to 4 anchor rods are uniformly arranged in the corresponding range of the coal gang 3 on both sides of the roadway 1, the top plate 2 anchors or anchor cables 6
  • the tensile strength exceeds 1600MPa, the length of the bolt is 3.5m ⁇ 5.0m; the tensile strength of the bolt 7 exceeds 300MPa, the length of the bolt is 1.2m ⁇ 2.0m, and the row spacing of the bolt is 1.5m ⁇ 2.0m.
  • the top plate 2 anchor or anchor cable 6 needs to be arranged vertically, and the allowable error cannot exceed 3°; the gang bolt 7 needs to be vertically arranged, and the allowable error cannot exceed 5°.
  • the top plate 2 anchor or anchor cable 6 has a pre-tightening force of 180 kN to 250 kN; and the gang bolt 7 has a pre-tightening force of 60 kN to 100 kN.

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  • Life Sciences & Earth Sciences (AREA)
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  • General Physics & Mathematics (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
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  • Environmental & Geological Engineering (AREA)
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  • Structural Engineering (AREA)
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  • Piles And Underground Anchors (AREA)

Abstract

一种基于顶板稳定性的煤巷强顶护帮锚杆支护方法，将巷道（1）顶板（2）划分为不同区域，分析各个区域的岩芯信息，从而获得顶板（2）各个区域的岩体完整性；通过分析各区域测试结果，判定顶板（2）各区域岩体质量指标，当岩体质量指标大于预设值时，则在该区域内顶板（2）均匀垂直布置多根锚杆或锚索单一强化支护，并在两侧煤帮（3）相应范围内均匀垂直布置多根锚杆。

Description

基于顶板稳定性的煤巷强顶护帮锚杆支护方法 技术领域
本发明涉及一种煤巷支护技术，尤其涉及基于顶板稳定性的煤巷强顶护帮锚杆支护方法。
技术背景
我国煤矿经过40余年的高速发展，采煤技术已经基本实现了现代化和机械化，而掘进工序中仅破煤、装煤和运煤实现了机械化，支护工艺仍靠人海战术。随着高产高效综采工作面的快速推进，需要在井下开掘大量的巷道，据不完全统计，国有大中型煤矿每年新掘进的巷道总长度高达8000km左右，80％以上是开掘在煤层中的巷道，因此，煤巷掘进的速度直接影响到矿井采掘接替。
近年来，随着掘进机、连采机、掘锚机等机械设备在巷道掘进施工中的大量应用，巷道掘进的机械化水平得到一定程度的提升，但远远不能满足现场要求，因为巷道的支护速度跟不上掘进速度，锚杆支护的时间占总掘进时间比重大。
现在煤巷支护大多采用的锚杆索联合支护，虽然在一定程度上能够满足工程现场需要，但是支护密度过大，支护工艺复杂，主动支护强度较小，使得巷道变形量较大，明显制约掘进速度，并时有发生顶板跨冒事故。
发明内容
本发明的目的是克服已有技术中的不足，提供一种基于顶板稳定性的煤巷强顶护帮锚杆支护方法。
为实现上述技术目的，本发明的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，包括步骤如下：将巷道顶板划分为不同区域，在各个区域中钻取岩芯，分析各个区域的岩芯信息，从而获得顶板各个区域的岩体完整性；
若检测的区域岩芯完整性超过预设值，则判断此区域岩层为较完整岩层或完整岩层，对此区域岩芯进行单轴抗压测试，通过分析各区域测试结果，判定顶板各区域岩体质量指标，当获得的区域岩体质量指标大于预设值时，则在该区域内顶板均匀垂直布置多根锚杆或锚索单一强化支护，并在两侧煤帮相应范围内均匀垂直布置多根锚杆。
详细步骤如下：
a)将巷道顶板划分为不同区域，在各个区域中钻取岩芯，统计分析岩芯中的节理裂隙f米每条,利用公式：Kv＝-0.0286f+0.836，求出岩体完整性指数Kv，从而获得顶板各个区域岩体的完整性；
b)当检测的区域岩芯完整性指数Kv≥0.55时，判断此区域岩层为较完整岩层或完整岩 层，将此区域岩芯加工成标准试件，并测定标准试件的单轴抗压强度σc；
c)根据岩体质量指标BQ公式：BQ＝90+3σc+250Kv,计算顶板岩体质量指标BQ，当顶板岩体质量指标BQ≤451时,判断顶板岩体为软岩或较软岩，则采用常规锚注支护；
d)当顶板岩体质量指标BQ＞451时,判断顶板岩体为硬岩或较硬岩，则在该区域内顶板均匀垂直布置4～6根锚杆或锚索单一强化支护，在巷道两侧煤帮相应范围内均匀垂直布置3～4根锚杆。
所述的顶板锚杆或锚索抗拉强度超过1600MPa，锚杆长度为3.5m～5.0m；所述的帮部锚杆抗拉强度超过300MPa，锚杆长度为1.2m～2.0m。
所述的顶板锚杆或锚索需垂直布置，允许误差不能超过3°；所述的帮部锚杆需垂直布置，允许误差不能超过5°。
所述的锚杆支护排距为1.5m～2.0m。
所述的顶板锚杆或锚索预紧力180kN～250kN；所述的帮部锚杆预紧力60kN～100kN。
有益效果：
(1)运用该支护方法后，由传统支护排距≤1m，直接提高到排距1.5m以上，大幅提高了锚杆支护排距，节省了支护时间，明显提升了煤巷掘进速度，同时巷道控制效果大幅度改善，单一化支护后，巷道掘进的施工工艺简化，进一步提高了掘进速度。
(2)由于顶板锚杆强度和长度的增加，锚杆预紧力的增大，锚杆的灵敏性也会大幅度提高，使得顶板岩层可实现多层双向联动，从而使顶板可形成足够厚度的锚固岩梁，提高巷道整体稳定性。
(3)顶板形成完整的锚固岩梁后，会大幅度缓解煤帮的压力，同时将帮部峰值压力的位置转移到靠近煤壁侧，从而促使煤帮由“支”向“护”的转变，使得煤帮可用强度较低的短锚杆即可控制帮部的变形，如此进一步提高帮部支护速度，从而提高巷道的掘进速度。
附图说明
图1为现有技术中支护形式及其巷道变形示意图；
图2为本发明的基于顶板稳定性的煤巷强顶护帮锚杆支护方法及其巷道变形示意图。
图中：1-巷道；2-顶板；3-煤帮；4-底板；5-裂隙；6-顶板锚杆或锚索；7-帮部锚杆。
具体实施方式
下面结合附图对本发明做更进一步的解释：
如图1和图2所示，本发明的一种煤巷强顶护帮锚杆支护方法步骤为：将煤巷顶板2划分为不同区域，工作人员在底板4上钻取各个区域顶板2岩芯，分析各个区域顶板2的岩芯 信息，从而获得各个区域顶板2的岩体完整性；
若检测的区域岩芯完整性超过预设值，则判断此区域岩层为较完整岩层或完整岩层，对此区域岩芯进行单轴抗压测试，通过分析各区域测试结果，判定顶板2各区域岩体质量指标，当获得的区域岩体质量指标大于预设值时，则在该区域内顶板2均匀垂直布置多根锚杆或锚索6单一强化支护，并在两侧煤帮3相应范围内均匀垂直布置多根锚杆7。
详细步骤如下：
a)将巷道1顶板2划分为不同区域，在各个区域中钻取岩芯，统计分析岩芯中的节理裂隙5,利用公式：Kv＝-0.0286f+0.836，求出岩体完整性指数Kv，f为节理裂隙(条/m)，从而获得顶板各个区域岩体的完整性；
b)当检测的区域岩芯完整性指数Kv≥0.55时，判断此区域岩层为较完整岩层或完整岩层，将此区域岩芯加工成标准试件，并测定标准试件的单轴抗压强度σc；
c)根据岩体质量指标BQ公式：BQ＝90+3σc+250Kv,计算顶板2岩体质量指标BQ，当顶板2岩体质量指标BQ≤451时,判断顶板2岩体为软岩或较软岩，则采用常规锚注支护；
d)当顶板2岩体质量指标BQ＞451时,判断顶板2岩体为硬岩或较硬岩，则在该区域内顶板2均匀垂直布置多根锚杆或锚索6单一强化支护，并在两侧煤帮3相应范围内均匀垂直布置多根锚杆7，在巷道1两侧煤帮3相应范围内均匀布置3～4根锚杆，所述的顶板2锚杆或锚索6抗拉强度超过1600MPa，锚杆长度为3.5m～5.0m；所述的帮部锚杆7抗拉强度超过300MPa，锚杆长度为1.2m～2.0m，锚杆支护排距为1.5m～2.0m。
所述的顶板2锚杆或锚索6需垂直布置，允许误差不能超过3°；所述的帮部锚杆7需垂直布置，允许误差不能超过5°。
所述的顶板2锚杆或锚索6预紧力180kN～250kN；所述的帮部锚杆7预紧力60kN～100kN。

Claims (6)

  1. 一种基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是包括步骤如下：将巷道顶板划分为不同区域，在各个区域中钻取岩芯，分析各个区域的岩芯信息，从而获得顶板各个区域的岩体完整性；
    若检测的区域岩芯完整性超过预设值，则判断此区域岩层为较完整岩层或完整岩层，对此区域岩芯进行单轴抗压测试，通过分析各区域测试结果，判定顶板各区域岩体质量指标，当获得的区域岩体质量指标大于预设值时，则在该区域内顶板均匀垂直布置多根锚杆或锚索单一强化支护，并在两侧煤帮相应范围内均匀垂直布置多根锚杆。
  2. 根据权利要求1所述的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是详细步骤如下：
    a)将巷道顶板划分为不同区域，在各个区域中钻取岩芯，统计分析岩芯中的节理裂隙f米每条,利用公式：Kv＝-0.0286f+0.836，求出岩体完整性指数Kv，从而获得顶板各个区域岩体的完整性；
    b)当检测的区域岩芯完整性指数Kv≥0.55时，判断此区域岩层为较完整岩层或完整岩层，将此区域岩芯加工成标准试件，并测定标准试件的单轴抗压强度σc；
    c)根据岩体质量指标BQ公式：BQ＝90+3σc+250Kv,计算顶板岩体质量指标BQ，当顶板岩体质量指标BQ≤451时,判断顶板岩体为软岩或较软岩，则采用常规锚注支护；
    d)当顶板岩体质量指标BQ＞451时,判断顶板岩体为硬岩或较硬岩，则在该区域内顶板均匀垂直布置4～6根锚杆或锚索单一强化支护，在巷道两侧煤帮相应范围内均匀垂直布置3～4根锚杆。
  3. 根据权利要求2所述的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是：所述的顶板锚杆或锚索抗拉强度超过1600MPa，锚杆长度为3.5m～5.0m；所述的帮部锚杆抗拉强度超过300MPa，锚杆长度为1.2m～2.0m。
  4. 根据权利要求2所述的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是：所述的顶板锚杆或锚索需垂直布置，允许误差不能超过3°；所述的帮部锚杆需垂直布置，允许误差不能超过5°。
  5. 根据权利要求2所述的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是：所述的锚杆支护排距为1.5m～2.0m。
  6. 根据权利要求2所述的基于顶板稳定性的煤巷强顶护帮锚杆支护方法，其特征是：所述的顶板锚杆或锚索预紧力180kN～250kN；所述的帮部锚杆预紧力60kN～100kN。
PCT/CN2018/105350 2017-12-08 2018-09-13 基于顶板稳定性的煤巷强顶护帮锚杆支护方法 WO2019109700A1 (zh)

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CN108035752A (zh) * 2017-12-08 2018-05-15 中国矿业大学 基于顶板稳定性的煤巷强顶护帮锚杆支护方法
CN111259542B (zh) * 2020-01-15 2024-03-08 中国矿业大学 一种巷道顶板锚固支护抗冲击能力的计算方法
CN111707548B (zh) * 2020-06-30 2021-08-27 中国矿业大学 一种基于裂隙和能量演化的锚杆支护效果评价方法
CN117145477B (zh) * 2023-10-30 2024-01-30 华能煤炭技术研究有限公司 一种地表均匀沉降的煤矿开采方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103225510A (zh) * 2013-03-22 2013-07-31 上海建科工程咨询有限公司 一种隧道掘进机隧道施工风险地图的构建方法
WO2016161480A1 (en) * 2015-04-10 2016-10-13 Fero Group Pty Ltd Improved drilling assembly comprising a friction bolt
CN106570292A (zh) * 2016-11-14 2017-04-19 中建山东投资有限公司 一种基于超大断面隧道的围岩分级方法
CN106780284A (zh) * 2016-12-28 2017-05-31 中铁工程装备集团有限公司 隧道洞壁围岩完整性信息采集装置及评价方法
CN107067333A (zh) * 2017-01-16 2017-08-18 长沙矿山研究院有限责任公司 一种高寒高海拔高陡边坡稳定性监控方法
CN108035752A (zh) * 2017-12-08 2018-05-15 中国矿业大学 基于顶板稳定性的煤巷强顶护帮锚杆支护方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104806275A (zh) * 2015-02-12 2015-07-29 中铁工程装备集团有限公司 不稳定围岩条件下的煤巷快速支护方法
CN106485031B (zh) * 2016-11-04 2019-08-30 青岛理工大学 一种风化岩体边坡预应力锚杆加固长度的优化设计方法
CN107288670B (zh) * 2017-08-10 2022-07-01 中国神华能源股份有限公司 一种对巷道进行支护的支护方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103225510A (zh) * 2013-03-22 2013-07-31 上海建科工程咨询有限公司 一种隧道掘进机隧道施工风险地图的构建方法
WO2016161480A1 (en) * 2015-04-10 2016-10-13 Fero Group Pty Ltd Improved drilling assembly comprising a friction bolt
CN106570292A (zh) * 2016-11-14 2017-04-19 中建山东投资有限公司 一种基于超大断面隧道的围岩分级方法
CN106780284A (zh) * 2016-12-28 2017-05-31 中铁工程装备集团有限公司 隧道洞壁围岩完整性信息采集装置及评价方法
CN107067333A (zh) * 2017-01-16 2017-08-18 长沙矿山研究院有限责任公司 一种高寒高海拔高陡边坡稳定性监控方法
CN108035752A (zh) * 2017-12-08 2018-05-15 中国矿业大学 基于顶板稳定性的煤巷强顶护帮锚杆支护方法

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