萬磊 孫茂如 郭輝
摘 要:隨著煤炭開采深度不斷增加,很多礦區(qū)在工作面布置上都存在近距離煤層采空區(qū)下回采的問題。由于上覆工作面回采后采空區(qū)內(nèi)垮落不充分,礦山壓力分布規(guī)律性不強(qiáng),且采空區(qū)下巷道掘進(jìn)期間,受二次擾動(dòng)影響易造成頂板裂隙發(fā)育,對(duì)上覆采空區(qū)形成漏風(fēng)通道,容易引發(fā)采空區(qū)內(nèi)有毒有害氣體外溢和采空區(qū)內(nèi)遺煤自燃事故,極近距離煤層采空區(qū)下大斷面巷道掘進(jìn)問題尤為突出。本論文以新集二礦2201采區(qū)首個(gè)采空區(qū)下工作面切眼掘進(jìn)為研究背景,制定了極近距離煤層上覆采空區(qū)下大斷面巷道掘進(jìn)施工方案,取得了成功并形成了類似條件下的安全掘進(jìn)綜合技術(shù)措施,為后續(xù)指導(dǎo)極近距離煤層上覆采空區(qū)下開采拓展了思路。
關(guān)鍵字:極近距離煤層;采空區(qū)下;大斷面;巷道掘進(jìn)
中圖分類號(hào):TD822? ?文獻(xiàn)標(biāo)識(shí)碼:A? ?文章編號(hào):1003-5168(2021)21-0067-04
Research on Tunneling Technique for the Cut-hole with the Large Section under Goaf in Extremely Close Coal Seams
WAN Lei? ? SUN Maoru? ? GUO Hui
(The Second Coal Mine of Xinji, China Coal Xinji Energy Co., Ltd, Huainan Anhui 232180)
Abstract: With the increasing of coal mining depth, many mining areas have the problem of mining under goaf in t extremely close coal seams. Because of the overlying after mining face goaf caving inadequate, the mine pressure distribution regularity is not strong, and under the goaf roadway drivage, affected by the secondary disturbance of the roof fracture, the overlying goaf air leakage passage formation, which is easy to cause the toxic or harmful gases within the mined-out area and traces of mined-out area in coal spontaneous combustion accident, the drivage problem with large section roadway under goaf in extremely close to the coal seams is particularly prominent. The research background of this pa per is the cut hole under goaf in 2201 mining area of xinji no.2 mine. The construction plan of the large section roadway under the extremely close coal seams is formulated. The comprehensive technical measures for safe tunneling under similar conditions have been developed successfully. The train of thought is expanded for the follow-up guidance of mining under goaf of the extremely close coal seams.
Keywords: extremely close coal seams; under goaf; large section; roadway excavation
新集二礦1煤組資源量約10 632.6萬t,保有儲(chǔ)量約6 393.5萬t,可采儲(chǔ)量約3 327.7萬t,其安全開采經(jīng)濟(jì)效益顯著、社會(huì)效益長(zhǎng)遠(yuǎn)。新集二礦1煤組由1上煤和1煤組成,其煤質(zhì)為1/3焦煤,其中1上煤厚度為3.3~3.8 m,平均厚度約3.6 m;1煤層厚度為2.6~3.6 m,平均厚度約3.0 m;兩次層夾矸為泥巖,厚度約為0.8~1.2 m,平均厚度約為1.0 m。受副井罐籠空間限制,最大可提升ZZ9200-24/50型液壓支架,其能力不能滿足1煤組一次采全高要求,因此,礦井針對(duì)1煤組開采時(shí)采取分層開采方式,即先開采1上煤工作面,待采空區(qū)冒落穩(wěn)定后再開采1煤工作面。
由于上覆工作面回采后采空區(qū)內(nèi)垮落不充分,礦山壓力分布規(guī)律性不強(qiáng),且?guī)r體受采動(dòng)影響裂隙較發(fā)育,極易形成漏風(fēng)通道,對(duì)工作面圍面及回采都將帶來很大的影響。雖然有些學(xué)者已對(duì)近距離煤層下行開采條件下的采場(chǎng)覆巖應(yīng)力演化[1-2]、工作面開采技術(shù)[3]、巷道掘進(jìn)支護(hù)方案[4-6]等方面進(jìn)行了深入研究,但對(duì)無法采取錨網(wǎng)支護(hù)的采空區(qū)極近距離煤層大斷面切眼掘進(jìn)支護(hù)工藝還沒有過多研究。
本文結(jié)合新集二礦極近距離煤層開采條件,制定了上覆采空區(qū)下極近距離煤層大斷面巷道掘進(jìn)支護(hù)方案和防治采空區(qū)遺煤自然發(fā)火措施,實(shí)現(xiàn)了首個(gè)極近距離煤層采空區(qū)下大斷面切眼安全施工,并保證了工作面支架順利安裝及回采,對(duì)類似條件下資源安全開采具有借鑒指導(dǎo)意義。