深部厚煤層動(dòng)靜載荷下區(qū)段煤柱損傷演化分析

雷照源 李團(tuán)結(jié) 崔峰 郭超奇 易瑞強(qiáng)

摘 要：深部厚煤層綜采工作面沿空開采下引發(fā)的煤柱動(dòng)力失穩(wěn)，是嚴(yán)重影響礦井的安全生產(chǎn)條件之一。以陜西某礦區(qū)留設(shè)35 m段煤柱穩(wěn)定性為研究對(duì)象，通過賦存條件調(diào)查、理論分析、數(shù)值計(jì)算、現(xiàn)場監(jiān)測等方法，分析區(qū)段煤柱在動(dòng)、靜載荷下的演化特征。研究表明：煤柱在靜載向動(dòng)載荷的轉(zhuǎn)化過程中，35 m煤柱內(nèi)部兩側(cè)的應(yīng)力峰值從2 m遷移至8 m，雙側(cè)擾動(dòng)下的應(yīng)力明顯高于煤體的抗壓強(qiáng)度;內(nèi)部的塑性破壞占比從9.52%增加至40%，最終35 m煤柱內(nèi)部形成“梯型”穩(wěn)態(tài)結(jié)構(gòu)。根據(jù)現(xiàn)場煤柱動(dòng)載荷影響，結(jié)合巷道布置方式提出進(jìn)行分區(qū)支護(hù)原則。實(shí)踐表明：巷道頂板及煤柱幫經(jīng)歷3種變化的位移特征，在距采空區(qū)70～90 m范圍的運(yùn)動(dòng)達(dá)到極限。因此，35 m煤柱能滿足開采極限條件下的支撐作用，滿足生產(chǎn)的實(shí)際需要。關(guān)鍵詞：深部厚煤層;動(dòng)載荷;靜載荷;區(qū)段煤柱

中圖分類號(hào)：TD 324

文章編號(hào)：1672-9315（2022）01-0091-08??????????? 文獻(xiàn)標(biāo)志碼：A

DOI：10.13800/j.cnki.xakjdxxb.2022.0113開放科學(xué)（資源服務(wù)）標(biāo)識(shí)碼（OSID）：

Damage evolution analysis of section coal pillar under

dynamic and static load in deep thick coal seam

LEI Zhaoyuan1，2，4，LI Tuanjie4，CUI Feng1，2，3，GUO Chaoqi4，YI Ruiqiang4

（1.College of Energy Science and Engineering，Xi’an University of Science and Technology，Xi’an 710054，China;

2.Key Laboratory of Western Mine Exploitation and Hazard Prevention，Ministry of Education，

Xi’an University of Science and Technology，Xi’an 710054，China;

3.Key Laboratory of Coal Resource Exploration and Comprehensive Utilization，

Ministry of Land and Resources，Xi’an University of Science and Technology，Xi’an 710054，China;

4.Shaanxi Shanmei Huangling Mining（Group）Co.，Ltd.，Huangling 727307，China）Abstract：The dynamic instability of coal pillar caused by gob mining in fully mechanized mining face of deep thick coal seam seriously affects the safety of mine production.

The section coal pillar（35 m） at a coal mine in Shaanxi province is taken as the research object.The research means are applied including occurrence condition investigation，theoretical analysis，numerical calculation and field monitoring to study evolution characteristics of section coal pillar under dynamic and static loads.Research shows that：under different loads，the peak stress on both sides of the 35 m coal pillar moves from 2 m to 8 m，and the stress under bilateral disturbance is obviously higher than the compressive strength of the coal.The proportion of plastic failure inside increases from 9.52% to 40%，and? a trapezoidal structure is formed inside of 35m pillar.According to the different mining influence of roadway in the field，the principle of partition support is proposed.It turns out that roof and coal pillar undergo three kinds of displacement characteristics，and the movement of goaf reaches the limit at 70 to 90 m.Therefore，35m coal pillar can play a good supporting role under the mining limit conditions and meet the production needs.Key words：deep thick coal seam;dynamic load;static load;section coal pillar

0 引 言

深部煤層賦存原巖應(yīng)力大，厚煤層回采擾動(dòng)應(yīng)力及影響范圍大，易導(dǎo)致回采期間面臨礦壓顯現(xiàn)強(qiáng)烈、巷道變形量大等現(xiàn)象的發(fā)生[1]。根據(jù)煤柱作用不同，主要分為4類[2]。區(qū)段煤柱作為工作面形成的基礎(chǔ)，合理的煤柱尺寸在其內(nèi)部彈性核的作用下起到保護(hù)巷道安全的作用。巷道成型及回采過程中，煤柱內(nèi)部應(yīng)力釋放分別呈現(xiàn)緩慢釋放和快速釋放2種不同模式，深部厚煤層開采進(jìn)一步導(dǎo)致煤柱劇烈變形，給災(zāi)害防治帶來的挑戰(zhàn)。近年來眾多學(xué)者充分考慮地質(zhì)構(gòu)造、開采時(shí)空關(guān)系等影響因素，分析了地表與采動(dòng)的關(guān)系[3-5]。隨著煤柱型動(dòng)力災(zāi)害在采動(dòng)下發(fā)生，通過多手段相結(jié)合模式，針對(duì)“一礦一特色”提出了與之相適應(yīng)的煤柱監(jiān)控檢測技術(shù)[6-9]。宋錄生等提出并建立了立“頂板-煤層”結(jié)構(gòu)體模型，通過對(duì)4種不同模型的沖擊傾向性試驗(yàn)，得出“頂板-煤層”結(jié)構(gòu)體沖擊傾向性高于純煤層或巖層測定結(jié)果[10]。陳紹杰等對(duì)不同高比的5組頂板砂巖-煤柱結(jié)構(gòu)體進(jìn)行單軸壓縮試驗(yàn)，得出不同的3種結(jié)論和砂巖破壞的動(dòng)態(tài)過程[11]。祁和剛等針對(duì)深部高應(yīng)力區(qū)段煤柱留設(shè)合理性，開展了并提出了“一高一低”的高應(yīng)力區(qū)段煤柱綜合卸荷技術(shù)的研究[12]。付玉凱等在分析煤柱留巷圍巖破壞機(jī)制的基礎(chǔ)上，提出深部煤柱留巷“卸-支-注”協(xié)同控制原理，術(shù)有效改善了煤柱留巷的圍巖力學(xué)屬性和應(yīng)力狀態(tài)[13]。王濤等分析了臨空煤柱巷道側(cè)沖擊地壓的成因和受夾持煤體的沖擊失穩(wěn)過程，得出了斷頂卸壓爆破可以有效切斷堅(jiān)硬懸板對(duì)煤柱的應(yīng)力傳遞[14]。伍永平等基于大傾角煤層長壁工作面“R-S-F”系統(tǒng)，研究了區(qū)段煤柱的應(yīng)力分布規(guī)律和失穩(wěn)破壞準(zhǔn)則，最終確定了區(qū)段煤柱寬度k滿足kZHo7ROntxU6O+CnUVXU1+oTLFKUt/OQ0u8RGzfWuhBeVk=