葛亭煤礦設(shè)計(jì)【含CAD圖紙+文檔】

壓縮包內(nèi)含有CAD圖紙和說明書,均可直接下載獲得文件，所見所得，電腦查看更方便。Q 197216396 或 11970985 專題部分承壓水上采煤技術(shù)研究劉園（中國礦業(yè)大學(xué) 江蘇 徐州 01080112）摘 要：隨著煤炭科學(xué)技術(shù)水平的不斷進(jìn)步、煤礦開采技術(shù)水平的不斷提高，承壓水上安全采煤技術(shù)也在不斷發(fā)展。承壓水上采煤的問題越來越來顯出重要性和迫切性。本文敘述了承壓水上采煤底板突水因素與類型，并將遙感技術(shù)應(yīng)用于巖溶陷落柱分布的預(yù)測中。關(guān)鍵詞：承壓水上；底板突水；采煤技術(shù)；采煤方法1 地下水與含水層1.1定 義地下水系：指地面以下所有的水。由于地下水水文工作者主要研究飽和帶中的水，他們利用地下水運(yùn)動(dòng)這個(gè)術(shù)語表示飽和帶中的水。在農(nóng)田排水及農(nóng)藝學(xué)中，這個(gè)術(shù)語還表示潛水面以上不完全飽和地層中的水。本書中，利用地下水這一術(shù)語主要表示飽和帶中的水。承壓水上采煤；又名帶壓開采，是指開采煤層底板含水層中承壓水頭高度高于回采工作面水平條件下的回采。含水層：含水層是指具有下述兩種性質(zhì)的地層或巖層；含有水；一般的野外條件下允許大量的水在其中運(yùn)動(dòng)。阻水層：與含水層相反，是一種可以含水，但在一般的野外條件下，不能大量導(dǎo)水的地層。從實(shí)用的觀點(diǎn)出發(fā)，阻水層可以認(rèn)為是隔水層。隔水層；存在于含水層與開采煤層底板、巷道和采空區(qū)之間的能阻礙或減弱水流動(dòng)的巖層，該巖層內(nèi)的孔隙不連通，地下水無運(yùn)動(dòng)條件，常以吸著水存在，無重力水。亦稱不遠(yuǎn)水層或保護(hù)層。陰水系數(shù)：又稱阻水系數(shù)，是指各種巖石的等值隔水層厚度總和()減去等值隔水層厚度的修正值()，除以水壓(p)所得的值，即V隔水系數(shù)；等值隔水層厚度的修正值，在確定防水煤柱時(shí)，的值為10m，在確定主要巖層含水層的相對隔水層厚度時(shí)，值為8m，其他情況下，值為5m；P水壓，MPa；等值系數(shù)。；M。 為選取標(biāo)準(zhǔn)單位厚度(如泥巖)的隔水一阻水作用值；為與Mo相比較的不同質(zhì)量而單位厚度相同的巖層的隔水一阻水作用值。部分等值系數(shù)見表1-1。突水系數(shù)：指水壓值與隔水層厚度的比值，即 （1-1）T突水系數(shù)，MPam；p水壓值；MPa；m隔水層厚度，m 。弱透水層：與含水層相反，弱透水層是一種導(dǎo)水速度十分緩慢的半透水層。通常稱為越流地層。非含水層：是既不含水又不導(dǎo)水的地層?？障犊臻g：巖石中沒有被固體顆粒占據(jù)的那一部分叫做空隙空間(或孔隙空間、孔隙、空隙，裂隙)?？障犊臻g合有水和(或)空氣。在地層內(nèi)只有連通的空隙才能起導(dǎo)水通道的作用。圖11表示巖石空隙的幾種類型?？障兜拇笮】梢詮木薮蟮氖?guī)r洞穴到水主要靠吸附力存在于其中的微小的亞毛細(xì)孔洞。巖石的空隙一般分為兩種，即原生空隙與次生空隙。含水層的垂向分布；地面以下的水在垂宜剖面上的分布可以按照空隙空間中含水的相對比例劃分成兩個(gè)帶：飽和帶與充氣帶。飽和帶中的全部空隙充滿著水。充氣帶位于飽和帶之上，其中同時(shí)包含著氣體(主要是空氣及水蒸氣)和水。圖12表示地面以下水的分布概況。水(例如大氣降水或灌溉水)自地面滲入，在重力作用下向下運(yùn)動(dòng)和聚集，最后在某些不透水地層之上充滿巖石中所有相互連通的空隙。在不透水地層之上形成了飽和帶。飽和帶的上界面為潛水面，潛水面是一個(gè)其表面上壓力等于大氣壓力的面。1.2含水層的分類大多數(shù)含水層是由非固結(jié)或部分固結(jié)的砂礫石組成，它們分布在廢礦井、古河道、平原和山谷之中。其范圍大小不同。厚度也可以從幾米到幾百米。在砂和礫石固結(jié)類巖石中，由于顆粒被膠結(jié)在一起，滲透性減小。在世界的許多地方，厚度、密度、孔隙率和滲透性有很大變化的石灰?guī)r地層是重要含水層，尤其在大部分原生石灰?guī)r被溶蝕遷移的時(shí)候。石灰?guī)r中的洞穴可以從微小的原生小孔到形成地下河道的大裂縫及大洞穴。由于水流沿?cái)鄬蛹靶拖度芙鈳r石，因而隨著時(shí)間的推移，它們被不斷擴(kuò)大，從而增大了巖石的透水性，最后石灰?guī)r地區(qū)發(fā)展為巖镕(喀斯特)地區(qū)。就大范圍而言，喀斯特含水層的宏觀性狀大致與砂礫石含水層相似，是煤礦帶壓開采的最大威脅?；鹕綆r、玄武巖是相當(dāng)好的含水層。玄武巖含水層的孔隙也許比松散砂礫石含水層小，但由于大多數(shù)孔穴具有連通的特點(diǎn)，故其滲透性可以比砂礫石含水層大很多倍。以巖床、巖脈和巖頸等形式出現(xiàn)的許多淺層浸入巖，滲透性都很小，其中絕大多數(shù)不含水，因此可以作為地下水流的阻隔邊界。結(jié)晶巖與變質(zhì)巖屬于相對不透水層，它們構(gòu)成弱含水層。當(dāng)這類巖石出現(xiàn)在地表附近時(shí)，由于風(fēng)化與破碎，滲透性會(huì)逐漸變大。粘土及粘土與粗粒物質(zhì)的混合物，雖然孔隙串一級(jí)很高，但由于孔隙小，故為相對不遠(yuǎn)水層。含水層可以看成是受降水和河流自然補(bǔ)給或通過井孔及其他人工方式補(bǔ)給的地下水水庫。含水層中的水可以通過泉和河流自然地排泄，也可以用人工方法從井中排出。含水層可以根據(jù)潛水面是否存在劃分為無壓含水層和承壓含水層兩大類。1.2.1承壓含水層承壓水是指充滿于二個(gè)隔水層之間的地下水。由于隔水頂板的存在，它的補(bǔ)給區(qū)小于分布區(qū)，動(dòng)態(tài)較穩(wěn)定，不易被污染，承受靜水壓力，當(dāng)?shù)匦芜m宜時(shí)，鉆孔開鑿到含水層后，水即可噴出地表，形成自流，故承壓水又被稱為自流水。承壓水的形成首先決定于地質(zhì)構(gòu)造，在適宜的地質(zhì)構(gòu)造條件下，無論孔隙水、裂隙水、巖溶水都可以形成承壓水。坯適宜于形成承壓水的地質(zhì)構(gòu)造大體可分為向斜構(gòu)造和單斜構(gòu)造，這二種地質(zhì)構(gòu)造，在不同的地質(zhì)發(fā)展歷史過程中，可以被一系列的榴曲和斷裂所復(fù)雜化因此可以看出自流水的形成與地區(qū)的地質(zhì)發(fā)展史有著密切的關(guān)系。適宜于承壓水形成的盆地構(gòu)造或向斜構(gòu)造在水文地質(zhì)學(xué)中稱為自流盆地。自流盆地按照水文地質(zhì)特征可分為3個(gè)組成部分：。補(bǔ)給區(qū)，6承壓區(qū)，c排泄區(qū)，如圖13。承壓含水層的補(bǔ)給區(qū)有地表補(bǔ)給、潛水補(bǔ)給及承壓水含水層之間的補(bǔ)給，如圖14。圖16所示。承壓水的補(bǔ)給來源可以是多方面的。首先來自面頭區(qū)的大氣降水補(bǔ)給。補(bǔ)給量大小主要取決于露頭區(qū)范圍大小、降水量、降水性質(zhì)、出露地段地形、含水層透水性等因索。當(dāng)露頭區(qū)內(nèi)存在地表水體時(shí)，地表水也可成為承壓水的補(bǔ)給水源。地表水有時(shí)通過場洞，深切河谷，隔水層尖滅的“天宙”地段滲漏補(bǔ)給承壓水。當(dāng)承壓水補(bǔ)給區(qū)位于潛水層下面，潛水則可泄入承壓含水層。潛水也可通過隔水頂板尖滅地段或弱透水層越流補(bǔ)給承壓水。生活、工業(yè)廢水有時(shí)大量酒人承壓含水層，成為其補(bǔ)給源。當(dāng)包含有幾個(gè)承壓含水層的大型自流盆地或自流斜地，通過導(dǎo)水?dāng)嗔鸦蛉跬杆畬拥脑搅髯饔?，各承壓含水層之間可以發(fā)生相互補(bǔ)給或排泄的現(xiàn)象。圖17為上升泉的形成條件示意圖。一般情況下，承壓含水層的儲(chǔ)水量大，壓力高出的威脅日趨嚴(yán)重，是礦井突水的主要含水層。1.2.2潛水含水層潛水是埋藏在地表以下第一個(gè)穩(wěn)定隔水層以上，具有自由水面的重力水。潛水一般埋藏在第四紀(jì)松散沉積物的孔隙中和裸露基巖的裂隙、镕陳中。潛水的自由水畫稱為潛水面。潛水面至地面的鉛直距離為該處潛水的埋藏深度。水面的絕對標(biāo)高稱為該處的潛水位。由潛水面至隔水底板頂面之間，均充滿重力水，稱為潛水含水層，其距離則為含水層的厚度，如圖18所示。多數(shù)情況下，潛水的分布區(qū)就是其補(bǔ)給區(qū)，二者完全一致。潛水面的形狀大多為傾斜的拋物線型，在特定條件下也可以是水平的。潛水面坡度變化可以很大，首先與地區(qū)的地貌形態(tài)有關(guān)，在強(qiáng)烈割切的山區(qū)。沿山坡一帶可達(dá)百分之幾，在乎坦的平原區(qū)中則只有千分之幾。一般地面坡度愈大，潛水面的坡度也愈大，二者經(jīng)常一致，而且潛水面的坡度總是小于地面坡度。其次含水層的變厚或因含水層透水性變好時(shí)，潛水面坡度也會(huì)趨于平緩在盆地或洼地可形成潛水湖，如圖18、圖19所示。潛水的補(bǔ)給主要是大氣降水和地表水，有時(shí)通過斷裂構(gòu)造帶由承壓水補(bǔ)給。其排泄一般為蒸發(fā)或補(bǔ)給于地表河流。由于地形的影響使?jié)撍纬蓧毫μ荻榷l(fā)生徑流。潛水含水層也是煤礦開采的一大威脅，尤其是在徑流帶、自流盆地處，如裂隙或構(gòu)造斷裂發(fā)育，可涌人礦井而發(fā)生淹井事故。1.2.3越琉含水層不論是承壓含水層還是無壓含水層均能通過其上或(和)其下的封閉地層獲得水或漏失水，這種含水層叫做越流含水層。雖然這類封閉地層具有較高的滲透阻力，但是當(dāng)它們在大范圍內(nèi)與所研究的含水層接觸時(shí)，大量的水可以通過它們流入或流出含水層。在各種情況下，越流量與越流方向均受弱透水地層兩側(cè)測壓水頭差的控制。顯然，在每一種具體條件下，含水層上覆的某個(gè)地層是不透水層，還是弱透水層或僅僅是滲透性與所考慮的含水層不同的另一種透水地層并不是一件容易的事。通常，考慮成弱逆水層的地層(即越流層)都比主含水層的厚度小。位于弱透水地層之上的潛水含水層(或其一部分)是一種有越流的潛水含水層。至少有一個(gè)弱透水封閉層的承壓含水層(或其一部分)叫做有超流的承壓含水層。圖110表示幾種含水層和觀測孔。上部為潛水含水層，其下有兩個(gè)承壓含水層。在補(bǔ)給區(qū)含水層B變?yōu)闈撍畬?。含水層A、B和c的一部分是有越流的，越流方向流量的大小取決于每個(gè)含水層的測壓水面高度。由于潛水位和承壓水頭高度的變化，各水層承壓和無壓部分之間的界線可以隨時(shí)間而變化。潛水含水層的一種特殊信形是上層捕水含水層。當(dāng)在潛水面和地面之間分布有局部不進(jìn)水(或相對不透水)時(shí)，在這種不適力地層之上就會(huì)形成另一種地下水體上層滯水含水層。沉積物中的土及亞粘土透鏡體經(jīng)常有薄的上層滯水含水層，有時(shí)這些含水層只能存在一個(gè)比較短的時(shí)間，因?yàn)樯蠈訙梢粤魅讼虏康臐撍畬印?.3含水層的性質(zhì)含水層的導(dǎo)水、貯水和給水度是含水層的主要性質(zhì)。水力傳導(dǎo)系數(shù)表示在水力梯度作用下臺(tái)水層傳導(dǎo)地下水的能力，它是多孔介質(zhì)和其中流動(dòng)著的流體的一種組合性質(zhì)。如果含水層中的流動(dòng)基本上為水平流動(dòng)，則含水層的導(dǎo)水系數(shù)表示通過含水層整個(gè)厚度的導(dǎo)水能力。導(dǎo)水系數(shù)等于含水層的水力傳導(dǎo)系數(shù)與含水層厚度的乘積。含水層的貯水系數(shù)表示存貯在含水層中的水量變化和相應(yīng)的測壓面高度變化之間的關(guān)系。承壓含水層的貯水系數(shù)定義為水頭降低(或升高)一個(gè)單位時(shí)，從水平棧截面為一個(gè)單位的含水層垂直柱體中釋出(或存入)的水的體積，如圖111所示。在潛水含水層的情況下，水實(shí)際上是由于潛水位降低而從空隙空問中排出并為空氣所代替，然而重力排水并不能排出包含在空隙空間中的全部水。一定量的水在分子引力與表面張力的支持下能夠抗住重力而保持在固體顆粒之間的空隙中。因此，潛水含水層的貯水系數(shù)比孔隙串小，其差稱為持水串(土樣中反抗重力作用而保持下來的水分與土樣總體積之比)。為了反映這種現(xiàn)象，通常把潛水含水層的貯水系數(shù)稱為給水度。由含水層和水的壓縮性所引起的彈性貯水系數(shù)要比給水度小得多。具體地說，大多數(shù)承壓含水層的貯水系數(shù)在loIo之間，而大多數(shù)沖積層的給水皮為10x。這說明排出(或注入)相同體積的水，承壓含水層中水頭高度的變化要比無壓含水層中水位高度的變化大得多。在定義承壓含水層的貯水系數(shù)時(shí)，假定不存在時(shí)間延遲問題，并且認(rèn)為水是隨著水頭的下降而瞬時(shí)釋出的。然而，尤其是在紉顆粒物質(zhì)中，由于低水力傳導(dǎo)系數(shù)限制著水自貯存中釋放，因而可以發(fā)生明顯的時(shí)間延遲現(xiàn)象。對于潛水含水層來說也是如此，因?yàn)槭栌谶^程槽要一定的時(shí)間。表示越流含水層特征的一個(gè)參數(shù)是弱透水層(又稱半封閉層)的阻力系數(shù)。阻力系數(shù)定義為弱透水層厚度與其水力傳導(dǎo)系數(shù)之比。當(dāng)這值較大時(shí)，通過弱透水層的越流量則較小。另一個(gè)參數(shù)叫做越流因數(shù)。它等于含水層的導(dǎo)水系數(shù)與弱透水層的阻力系數(shù)的乘積的平方根。在確定某一地層是否為含水層以及為何種類型的含水層時(shí)，上述各種參數(shù)可作為指標(biāo)。2 底板突水類型煤層底板突水實(shí)質(zhì)是煤層下伏承壓水沿采煤工作面底板隔水層巖體內(nèi)部通道突破底板隔水層的阻隔，以突發(fā)、緩發(fā)或滯發(fā)的形式向上涌人工作面采空區(qū)的過程。研究它的發(fā)生、發(fā)展規(guī)律是進(jìn)行突水預(yù)測預(yù)報(bào)的前提，是制定合理開采方案和預(yù)防措施的依據(jù)。因此，研究突水的機(jī)理，對突水進(jìn)行分類是很重要的。同時(shí)各種不同類型的底板突水在其成分上是不同的，為了查明底板突水產(chǎn)生的原因和條件，首先因?qū)Φ装逋凰M(jìn)行分類。2.1按突水地點(diǎn)分為巷道突水和采場突水。巷道突水多以構(gòu)造破壞為主，承壓水通過斷裂或構(gòu)造破碎帶進(jìn)入底板，形成充水，一旦巷道揭露出來后，承壓水就迅速涌入。采場突水多以采礦破壞為主，礦山壓力破壞和消弱了底板隔水層的厚度和強(qiáng)度，造成與汗水層的密切水力聯(lián)系。2.2按突水的動(dòng)態(tài)分為爆發(fā)型、緩沖型和滯后型三種。爆發(fā)型主要是由于存在充水?dāng)鄬蛹由贤凰幍牡装甯羲芰苋跻鸬?，其突水的特點(diǎn)為來勢猛、速度快和沖擊力強(qiáng)等。緩沖型主要是由采礦、構(gòu)造破壞等迭加作用所造成的。由于突水處有一定的隔水能力，突水來的慢，量由小到大。滯后型主要是承壓水沿裂隙長期沖蝕及礦壓持續(xù)作用的結(jié)果。2.3按突水量大小分為特大型突水、大型突水、中型突水和小型突水，如表2-1：表2-1 按突水量大小底板突水分類突水類型小型中型大型特大型突水量/（）503 影響底板突水的主要因素煤層底板突水有兩個(gè)必要條件：一是要有突水的水源條件，二是要有能進(jìn)行突水的通道條件。3.1水源條件水源條件包括水量和水壓，水量愈豐富，突水條件越大，危險(xiǎn)也就愈大。水壓是突水的動(dòng)力，處于封閉狀態(tài)的巖溶水不斷溶蝕、沖刷裂隙，形成通道，由含水層進(jìn)入底板隔水層，水壓愈大，破壞愈嚴(yán)重。3.2地質(zhì)構(gòu)造地質(zhì)構(gòu)造主要指的是斷裂構(gòu)造，它是突水的主要控制因素，斷裂構(gòu)造的存在破壞了煤層底板的完整性，降低了巖體本身的強(qiáng)度，削弱了底板隔水層阻抗變形的能力。導(dǎo)致一定厚度的斷層或斷裂破碎帶的存在，如果為充水構(gòu)造或?qū)畼?gòu)造，那么當(dāng)工作面推進(jìn)到該斷裂帶，甚至接近該斷裂帶時(shí)，都將會(huì)導(dǎo)致承壓水的直接涌出，造成突水事故。3.3隔水層的阻水能力底板隔水層是唯一起阻隔突水作用的因素，隔水層的阻力能力取決于隔水層的強(qiáng)度、分層厚度和裂隙發(fā)育程度。在其他條件一定的情況下，隔水層厚度越大，強(qiáng)度越高，突水的機(jī)率也就越小。3.4礦山壓力開采引起的支撐壓力誘發(fā)底板突水，有以下規(guī)律：（1） 無周期來壓或周期來壓不明顯的頂板，支撐壓力較小，對底板破壞較輕；有周期來壓的頂板，底板突水多發(fā)生在初次來壓或周期來壓期間，只是由于來壓期間支撐壓力較正常推進(jìn)時(shí)大，對底板破壞嚴(yán)重。（2） 突水點(diǎn)位置多數(shù)在工作面后部采空區(qū)邊緣附近。這些位置處頂板垮落不充分，底板處于膨脹狀態(tài)，斷裂張開，阻水能力最弱。（3） 頂板初次來壓之前，在開切眼附近，由于基本頂大面積較長時(shí)間的懸露，或直接頂巖層跨落后不接頂，使底板巖層形成較大的自由面，給底板巖層的移動(dòng)與破壞創(chuàng)造了條件。（4） 工作面推進(jìn)速度慢，工作面突然停止推進(jìn)或在停采線處容易發(fā)生突水事故。這是由于支撐壓力作用的時(shí)間較長，底板破壞較嚴(yán)重。工作面推進(jìn)速度快時(shí)，采空區(qū)底板未形成較大裂隙就會(huì)由膨脹狀態(tài)變?yōu)閴嚎s狀態(tài)，這有利于防止底板突水。4 承壓水體上采煤4.1承壓水體上采煤底板突水的一般規(guī)律經(jīng)過長期的研究和實(shí)踐，我國已經(jīng)基本能掌握影響承壓水體上采煤底板突水的主要因素及一般規(guī)律。主要包括以下幾點(diǎn):（1）突水水源為底板強(qiáng)承壓含水層，大多為富水性好、水壓力大的灰?guī)r含水層。（2）在開采工作面，突水點(diǎn)大多分布在工作面煤壁附近、上下平巷邊緣以及切眼、停采線處的煤壁附近。（3）突水事故與構(gòu)造特別是斷層密切相關(guān)，70%以上的突水事故都與構(gòu)造影響相關(guān)。（4）底板承壓含水層水壓、底板隔水巖層的厚度及隔水性能對底板突水有顯著影響。底板承壓含水層水壓越大，底板隔水巖層的厚度越小，隔水層的阻水能力越差，越容易發(fā)生突水事故。（5）底板突水與采動(dòng)礦壓顯現(xiàn)有很強(qiáng)的一致性，而且絕大多數(shù)都發(fā)生在頂板來壓前后，頂板的初次來壓和二次來壓時(shí)，發(fā)生底板突水事故占總底板突水事故的 90%。（6）底板突水與原始導(dǎo)高有一定關(guān)系。底板含水層地下水未受采動(dòng)影響時(shí)，沿隔水巖層底部導(dǎo)水裂隙上升一定高度，這個(gè)高度稱為原始導(dǎo)高。原始導(dǎo)高越大，越容易發(fā)生底板突水。4.2承壓水體上采煤技術(shù)在承壓水體上采煤，要根據(jù)具體的地質(zhì)和開采技術(shù)條件，選擇合適的治理方案。根據(jù)我國近幾年來的實(shí)踐，主要有以下幾種方法:（1） 疏水降壓技術(shù)。疏水降壓是指煤層頂?shù)装搴畬踊蛎合档貙雍畬?，通過地表及地下疏干方式，并借助疏水巷道、抽水鉆孔和吸水鉆孔及相應(yīng)的排水設(shè)備，使煤層頂?shù)装搴畬铀畨航档椭敛擅喊踩畨?。?） 帷幕注漿堵水技術(shù)。帷幕注漿堵水是煤礦實(shí)現(xiàn)疏堵結(jié)合的有效措施之一。帷幕工程的目的是使外來水源中的大部分截堵在煤層開采范圍之外，而開采區(qū)域內(nèi)部可以通過疏水降壓等方法實(shí)現(xiàn)安全回采。（3） 帶壓采煤綜合治理技術(shù)。帶壓開采就是利用隔水層采煤。一定厚度的隔水層具有一定抵抗水壓的能力，并可以安全開采到一定深度的煤層。帶壓開采無需事先專門排水，一般也可以做到安全生產(chǎn)，但是，在水文地質(zhì)條件復(fù)雜的地區(qū)，卻存在底板突水的危險(xiǎn)，并且當(dāng)開采深度延伸后，水壓增大到隔水層厚度不能抵抗的時(shí)候，又會(huì)給帶壓開采帶來很大的難度。因此，這里提出了帶壓開采綜合治理方案，其特點(diǎn)和內(nèi)容主要包括: “以防為主，帶壓開采，適當(dāng)疏排，輔以截堵”。具體說就是以防水為指導(dǎo)思想，在查清區(qū)域和礦井水文地質(zhì)條件的基礎(chǔ)上，進(jìn)行帶壓采煤。在采前和采煤過程中，可在礦區(qū)外圍截堵地下補(bǔ)水源，盡量減少奧灰水的動(dòng)儲(chǔ)量; 同時(shí)，在帶壓采煤中，根據(jù)礦井涌水量大小和水壓大小，進(jìn)行適當(dāng)?shù)氖杷祲?，最終實(shí)現(xiàn)安全開采的目的。4.3底板突水的防治措施底板防治水技術(shù)措施可根據(jù)具體的地質(zhì)水文條件來選擇，同時(shí)還受到礦井的生產(chǎn)實(shí)際、采煤方法以及經(jīng)濟(jì)投入能力等多因素制約，因此需要根據(jù)多方面的綜合分析后，并在試驗(yàn)的基礎(chǔ)上，確定較為合理的底板防治水技術(shù)措施。（1） 全礦井疏水降壓。從理論上看，當(dāng)?shù)装宄袎汉畬铀畨哼^大，水體上煤層開采安全性不足時(shí)，可以采取疏水降壓等技術(shù)措施，降低底板承壓含水層水壓，將其控制在安全范圍之內(nèi)，從而消除底板承壓含水層的突水威脅，解放水體上壓煤資源。（2） 局部疏水降壓。當(dāng)?shù)装宄袎汉畬痈凰院?，或補(bǔ)給條件好、動(dòng)儲(chǔ)量大、全礦井疏降底板承壓含水層難度很大，不具備技術(shù)經(jīng)濟(jì)合理性時(shí)，在一定條件下，在開采工作面周圍局部疏水降壓，使開采工作面底板含水層在開采期間和開采后一定時(shí)間內(nèi)持續(xù)處于安全范圍內(nèi)，可有效避免底板突水。（3） 底板隔水層注漿改造。在底板隔水巖層隔水性能差、有底板突水危險(xiǎn)時(shí)，采用注漿方法加固改造隔水巖層，主要是通過鉆孔進(jìn)行注漿，堵塞石灰?guī)r溶洞，加固破碎帶和裂隙帶，并封閉奧陶系石灰?guī)r的補(bǔ)給通道，以實(shí)現(xiàn)在承壓水體上安全采煤。4.4承壓水上采煤方法4.4.1條帶采煤方法關(guān)于條帶開采法王作宇(1993)已作了詳盡的研究，此方法是把煤層劃分為比較正規(guī)的條帶狀進(jìn)行開采，采一條，留一條，其回采率低，工作面搬家次數(shù)較多，不利于機(jī)械化開采，但由于條帶采煤法能夠大幅度降低覆巖移動(dòng)強(qiáng)度，穩(wěn)定底扳，特別是在煤層上覆巖層中有厚層狀堅(jiān)硬巖層，煤層底板巖層也較堅(jiān)硬時(shí)，效果更為顯著。所以條帶法開采是承壓水上采煤的主要開采方法之一。4.4.1.1條帶煤柱的圖設(shè)原則 (1)能使煤柱起到長期支撐覆巖的作用，不被壓垮或破壞。 (2)在一般情況下，條帶煤柱寬高比為：充填條帶大于2，冒落條帶大于50 (3)煤層底板只發(fā)生輕微的、均勻的移動(dòng)和變形，不產(chǎn)生較大的破壞，仍能起到阻止承壓水上移的作用。4.4.1.2條帶開采法分類(1)冒落和充填條帶開采。采用全部垮镕法管理頂板的方法稱冒溶條帶法。日落條帶法則具有工藝簡單等優(yōu)點(diǎn)。采用充填法管理頂板的開采方法稱為充填法。充填物不僅可以支承頂板，更主要的是對保留煤柱的維護(hù)，由單向受力狀態(tài)轉(zhuǎn)變?yōu)槿蚴芰顟B(tài)，提高煤往的承載能力，有助于頂板的長期穩(wěn)定。(2)定采留比和變采留比條帶開采。在一個(gè)工作面內(nèi)采留比是固定不變的，叫定采留比條帶開采，定采留比的條帶布置要求嚴(yán)格，適用于采區(qū)地質(zhì)條件比較簡單的地段。在一個(gè)工作面內(nèi)采留比不是固定的，叫變采留比條帶開采。變采留比的條帶布置靈活，在采區(qū)地質(zhì)條件變化較大的地段采用有一定的優(yōu)越性。(3)傾斜條帶開采和走向條帶開采。傾斜條帶開采的條帶長軸順煤層傾斜布置。它的適應(yīng)性較強(qiáng)缺點(diǎn)是工作面搬家次數(shù)頻蟹。走向條帶開采的條帶長軸顧煤層走向布置。它適應(yīng)于傾角較緩的煤層，解決了工作面搬家次數(shù)領(lǐng)繁問題，但增加了巷道掘進(jìn)量。正確確定條帶尺寸，是取得條帶法開采良好效果的決定性因宏。在確定條帶尺寸時(shí)，必須道守兩個(gè)基本原則，一是確保開采后條帶煤柱應(yīng)有足夠的強(qiáng)度和穩(wěn)定性，以承受上覆巖層的壓力，減小覆巖的礦壓顯現(xiàn)。二是條帶開采的每一采出寬度，其尺寸應(yīng)足以使底板巖層移動(dòng)員小，最大限度地減小底板破壞深度。生產(chǎn)實(shí)踐及理論研究證明，煤柱尺寸取決于采深、采厚、采寬，上覆巖層容雹、煤的抗拉強(qiáng)度、底板水壓值等因索。采寬則取決于煤往尺寸、頂?shù)装宓牧W(xué)特性及底板水力值等。4.4.2短壁式采煤方法工作面長度是影響底板破壞深度的主要因素之一，減小工作面長度是控制底板突水的主要開采措施。水文地質(zhì)條件較復(fù)雜的礦區(qū)如采用長壁開采存在底板突水危險(xiǎn)時(shí)，可用短壁式開采，以減少突水幾率保證安全采煤。因?yàn)槎瘫谑讲擅悍捎行У販p弱底板破壞強(qiáng)度，縮小破壞深度，增大中部未破壞層的厚度，有效地阻止底板巖溶承壓水的浸入。在相同工藝和水文地質(zhì)條件下，走向長壁工作面的走向長度改變后不會(huì)導(dǎo)致礦壓的改變，因?yàn)椴珊笥?0m以外的壓力恢復(fù)區(qū)可表現(xiàn)為采后壓力常態(tài)區(qū)；基本接近來前狀態(tài)。對礦壓大小起作用的是采后o60m左右的老頂懇頂距及堵落情況。但當(dāng)工作面長度變化時(shí)，底板抗水壓的能力逐漸降低，在印m以外，抗水壓能力幅度減小不明顯，如圖4-1所示。從底板破壞帶實(shí)測資料分析中得知，工作面條件基本相似的情況下，工作面長度增加33倍，底板破壞深度增加4倍，在底板隔水層厚度不變的前提下，減小工作面長度，可減小底板破壞深度，增大相對隔水層厚度，增強(qiáng)抗水壓能力。因此，短壁式采煤法在防止底板突水方面具有重要作用。4.4.3 采區(qū)內(nèi)分段后退式采煤方法除上述介紹的方法以外，承壓水上采煤常用的方法還有：琉水降壓法、帳幕法、底板隔水層帶壓開采法等。一般情況下，由于礦區(qū)水系龐大、補(bǔ)給好、水頭高、奧灰水層厚，疏水降壓法和帳幕法實(shí)施的可能性較小。這些方法對地下水資源破壞嚴(yán)重，是環(huán)保法所不容許的。因此，尋求安全、高效的承壓水上開采方法是煤炭工業(yè)面臨的重大課題。圖4-1 工作面斜長(L)與底板承壓水壓力(p)的關(guān)系曲線4.4.3.1 帶壓分段后退式開采布局目前國內(nèi)外廣泛采用的開采順序在傾斜方向上有前進(jìn)式和后退式兩種，但在承壓水上采煤中，大都采用前進(jìn)式。這種方法具有先易后難，先淺后深，逐漸實(shí)現(xiàn)安全帶壓開采，初期投資小、見效快等優(yōu)點(diǎn)，缺點(diǎn)是；避災(zāi)困難由于每個(gè)工作面總是處于采空區(qū)的最低位量，其下僅有容量有限的水倉，一旦發(fā)生突水，首先淹沒工作面，直接威脅礦工和設(shè)備的安全。始終處于危險(xiǎn)狀態(tài)下開采，每個(gè)工作面總是在頂、底板充分?jǐn)_動(dòng)情況下回采的突水的可能性最大、最危險(xiǎn)。一個(gè)工作面一旦發(fā)生突水，只好關(guān)閉采區(qū)，其余區(qū)段將無法采出。救災(zāi)困難，由于突水位于最低點(diǎn)，欲堵水恢復(fù)生產(chǎn)，必須輔以強(qiáng)大的排水系統(tǒng)采區(qū)水位降至最低點(diǎn)，并在最危險(xiǎn)的狀態(tài)下，實(shí)施堵水?；谝陨先秉c(diǎn)，經(jīng)過深入理論分析和開采實(shí)踐總結(jié)，作者提出了“帶壓分段后退式開采布局法”。首先，根據(jù)承壓水上采煤理論和實(shí)踐及礦區(qū)水文地質(zhì)與工程地質(zhì)條件，做出正確的帶壓開采分區(qū)，即按突水系數(shù)和煤層標(biāo)高劃分為安全區(qū)、較安全區(qū)和危險(xiǎn)區(qū)等，如圖85所示。如東山煤礦?650m水平以上，突水系數(shù)小于O4，為安全區(qū)I；十550+650m水平，突水系數(shù)04O5，為安全區(qū)；十450+550m水平，突水系數(shù)0.50.6，為較安全區(qū)；+450m水平以下，突水系數(shù)大于0.6，為危險(xiǎn)區(qū)IV o根據(jù)目前礦井的開采技術(shù)和管理水平，+450M水平以上為可采區(qū)，+450m水平以下為暫不開采區(qū)。然后，根據(jù)采區(qū)的頂、底板巖性和斌存特征，依據(jù)工作面長度與底板承受的水壓關(guān)系，確定每個(gè)區(qū)的安全開采工作面長度和首采工作面長度，確保首采工作面安全開采。如東山煤礦底板隔水層厚度平均79m，依據(jù)我國帶壓開采突水的實(shí)踐，確定第l安全區(qū)的工作面長度為120m，推進(jìn)長度為8001000m，第2安全區(qū)工作面長度為如90m推進(jìn)長度500800M；較安全區(qū)的工作面長度為60M，推進(jìn)長度300500m，在這樣的采空面積條件下，可確保首采工作面安全回采(斷層構(gòu)造區(qū)除外)。最后，在每個(gè)分區(qū)內(nèi)，每個(gè)采區(qū)的區(qū)段實(shí)行由下向上的上行后退式回采，也就是說，每個(gè)分區(qū)的每個(gè)采區(qū)的首采工作面是在最危險(xiǎn)區(qū)，但恰在員安全的狀態(tài)下回采，其原則是：在監(jiān)測、排水、堵水、管理、未擾動(dòng)的最安全狀態(tài)下，用小面快速推進(jìn)開采本分區(qū)最深處的一個(gè)工作面，從而解放其他工作面。5 工程實(shí)例煤層頂?shù)装宀蓜?dòng)研究工作的深入,促進(jìn)了承壓水上采煤技術(shù)的迅速發(fā)展。多種采煤方法的運(yùn)用,擴(kuò)大了水上采煤范圍,使承壓水上采煤成為礦井挖潛增產(chǎn)、減少資源積壓和浪費(fèi)的重要途徑。由于多年的開采,焦煤公司朱村礦資源現(xiàn)已枯竭,主采煤層二1煤只剩下些殘留煤柱,目前大量開采一5煤已提上日程。一5煤層地質(zhì)構(gòu)造比較復(fù)雜,斷裂較發(fā)育,底板巖層含水量較大,水壓較高,屬于承壓水上煤層。為有效防止一5煤突水事故的發(fā)生,在主采盤區(qū)(54區(qū))采用膏體充填技術(shù)處理采空區(qū)并結(jié)合帶壓開采綜合防治方法,有效地防止了工作面突水。5.1底板突水因素分析5.1.1水源條件根據(jù)巖性和地下水的貯存埋藏條件及含水性等特征,朱村礦一5煤層底板自上而下主要有2個(gè)含水層。(1)L2灰?guī)r巖溶裂隙含水層。該層厚2281000 m,平均693 m,分布較穩(wěn)定。其巖溶裂隙發(fā)育很不均勻,靠近斷層帶巖溶裂隙較發(fā)育,富水性好;在完整地段發(fā)育較差。該層水在遇斷層或礦壓集中地帶多發(fā)生底鼓突水,突水量一般為1550m3/min,最大達(dá)10 m3/min,該層水富水性強(qiáng),水源充沛,是一5煤開采時(shí)底板突水威脅最大的含水層。(2)O2灰?guī)r溶洞裂隙含水層。該層厚350400 m,為上部煤系地層的基底,其巖溶裂隙非常發(fā)育。該含水層以間接方式補(bǔ)給上覆石炭系各層灰?guī)r含水層,對一5煤開采一般不會(huì)直接造成威脅,但由于斷層錯(cuò)動(dòng),使O2灰?guī)r與石炭系L8灰?guī)r、L2灰?guī)r對接或使它們之間的距離變短,也會(huì)造成礦井突水或突水量增大,威脅礦井安全生產(chǎn)。5.1.2礦山壓力在支承壓力1作用下,從煤體邊緣到采空區(qū)一定距離和一定深度內(nèi)的底板出現(xiàn)水平拉應(yīng)力;在壓縮區(qū)和膨脹區(qū)分界處的底板中出現(xiàn)剪應(yīng)力。拉應(yīng)力和剪應(yīng)力使底板出現(xiàn)了一系列垂直于層面的裂隙。垂直裂縫交叉,形成底板破壞帶,從而在煤層底板形成了“下三帶”,如圖5-1所示。當(dāng)h2=0時(shí),極易使破壞帶與含水層或?qū)龓噙B通,發(fā)生突水事故。5.1.3隔水層對一5煤開采威脅最大的是L2灰含水層,L2頂距一5煤底10252117 m,平均1576 m,隔水層巖性為泥巖、粉砂巖及薄層灰?guī)r(L4、L3),該區(qū)隔水層厚度分布情況是:西部厚(20742117 m),東部薄(11561340 m);北部厚,南部薄。O2灰?guī)r上距一5煤底35214945 m,平均4163 m;O2灰?guī)r上距L2底1364206 m,平均1720 m;L2底距O2頂?shù)母羲畬訋r性為粉砂巖、煤線及鋁土。上述隔水層具有一定的阻水能力,但由于巖溶較發(fā)育,水文地質(zhì)較復(fù)雜,大大影響了隔水層的阻水性能,使突水危險(xiǎn)性加大。圖5-1 底板下三帶示意圖5.1.4補(bǔ)給條件該區(qū)南界的三號(hào)井?dāng)鄬幽仙苯?造成該斷層南盤的O2灰?guī)r與該區(qū)的L8、L5、L2灰?guī)r對接,成為該區(qū)L8、L5、L2灰?guī)r的強(qiáng)大補(bǔ)給水源,因此三號(hào)井?dāng)鄬訛閷?dǎo)水?dāng)鄬?。斷裂?gòu)造可以充水導(dǎo)水,使隔水層的實(shí)際強(qiáng)度降低,使底板隔水層的有效厚度減小或消失,從而導(dǎo)致突水事故。5.2承壓水上采煤方法5.2.1膏體充填開采技術(shù)膏體充填開采就是把煤礦附近的煤矸石、粉煤灰、爐渣、劣質(zhì)土、城市固體垃圾等在地面加工成不需脫水的牙膏狀漿體(低成本的特殊“混凝土”),利用充填泵或重力作用通過管道輸送到井下、適時(shí)充填采空區(qū)的采礦方法,對煤礦采空區(qū)進(jìn)行充填,達(dá)到支撐上覆巖層、防止地表沉陷的目的。該礦54002工作面采用普采,使用膏體充填技術(shù)處理采空區(qū)。在工作面的推進(jìn)過程中,對工作面兩巷進(jìn)行礦壓觀測和對工作面底板進(jìn)行注水試驗(yàn)得出了一些工作面頂?shù)装遄冃魏推茐囊?guī)律。5.2.1.1工作面礦壓觀測在54002工作面膠帶巷和軌道巷分別建立測站2進(jìn)行觀測,以期得出充填體對圍巖控制作用的效果和規(guī)律,最大限度地控制圍巖變形,防止底鼓突水和地表下沉,保證工作面兩巷完好。礦壓觀測結(jié)果如圖5-2、圖5-3所示。圖5-2 巷道頂?shù)装逡平繄D5-3 巷道兩幫移近量工作面采用膏體充填法開采,頂板結(jié)構(gòu)在工作面煤壁前方受煤體的支撐,在工作面內(nèi)受支柱或支架支撐,而在采空區(qū)受充填體支撐,形成了“煤壁回采工作面支架(支柱)采空區(qū)充填體”的支撐體系。在上述支撐體系的作用下,頂板結(jié)構(gòu)保持完整,基本頂在變形過程中能夠較好地受到由“頂板充填體底板圍巖”力系的約束,礦壓顯現(xiàn)明顯緩和,圍巖移近量很小。(1)工作面前方1020 m處煤層上覆巖層開始運(yùn)動(dòng),但下沉速度很小,為巖層起始沉降期。(2)由進(jìn)、回風(fēng)巷測站工作面推過后期測量數(shù)據(jù)看出,工作面前后1015 m范圍內(nèi),巷道頂?shù)装逡平兓俣仍龃?下沉量占最終下沉量的80%左右,為巖層主要下沉期。在此區(qū)域工作面及兩巷支撐壓力較大,做好對工作面前后支撐壓力范圍內(nèi)的強(qiáng)有效的支護(hù),在控制巷道變形的作用中至關(guān)重要。(3)工作面后方20 m以外,上覆巖層沉降速度減緩并基本趨于穩(wěn)定,下沉量占最終下沉量的15%左右,稱為巖層沉降衰減期。(4)由觀測數(shù)據(jù)可知,頂?shù)装遄畲笠平繛?5mm,兩幫最大移近量為225 mm,礦壓顯現(xiàn)較緩和,膏體充填效果明顯。5.2.1.2底板注水試驗(yàn)為有效防止工作面突水,在54002工作面進(jìn)風(fēng)巷進(jìn)行鉆孔注水試驗(yàn)。共施工8個(gè)鉆孔(圖5-4)。圖5-4 鉆孔布置及局部地質(zhì)從距工作面50m進(jìn)行觀測，到工作面采過30m結(jié)束，得到的觀測數(shù)據(jù)如圖5到圖7所示。由觀測數(shù)據(jù)分析得出以下結(jié)論:(1)在受斷層影響被3條斷層切割的塊狀區(qū)域內(nèi),終孔位置距離斷層交界面10 m左右的1#5#鉆孔在開采過程中受斷層面活化影響較小;其注水量明顯變化的2#鉆孔是由于其部分測試段位于小煤層,而從其他鉆孔的注水量來看,巖層沒有因采礦引起整體破壞,推斷因礦壓造成的直接底破壞深度小于5 m。(2)斷層交界面的6#鉆孔表明,受采礦、區(qū)域水文地質(zhì)和承壓水影響,斷層面附近破碎帶活化,破碎帶滲透性大大增強(qiáng),L4灰?guī)r與石英砂巖等破碎帶富水區(qū)域的水能夠通過巖層與層的離層和溝通裂隙涌出至直接底板。所以6#鉆孔可以看作是受斷層影響較為劇烈的典型地點(diǎn),從而推斷在受斷層影響較為劇烈區(qū),底板破壞深度大于10 m,參考7#鉆孔注水曲線,可以判斷破壞深度在1012 m。且斷層附近巖層受擾動(dòng)是在工作面前方10m處,但受采礦影響最為明顯的區(qū)域是在工作面后20m處,底板突水應(yīng)多為滯后突水,所以在受大斷層影響突水危險(xiǎn)性很高的局部區(qū)域,注漿鉆孔應(yīng)提前打在工作面-1020 m范圍內(nèi),這時(shí)底板原生裂隙開始擴(kuò)展溝通,是注漿的最佳地段,以此防止底板滯后突水。(3)斷層附近深孔8#孔再次導(dǎo)升破碎帶高度在46 m,按照底板“下三帶”的理論,一5煤底板有效隔水層為厚47m的石英砂巖,這是按照底板鉆孔的底板巖層柱狀圖資料計(jì)算得到的。5.2.2帶壓開采綜合治理方法帶壓開采綜合治理方法是在查清區(qū)域地質(zhì)、礦井水文地質(zhì)及構(gòu)造地質(zhì)情況的基礎(chǔ)上進(jìn)行帶壓開采。焦作礦區(qū)采取“堵、疏、探、排”相結(jié)合的帶壓開采綜合治理方案,在防治底板突水方面取得了比較明顯的效果。該方法采取水文地質(zhì)分析及物探手段,正確分析突水水源和富水區(qū),弄清導(dǎo)水通道,然后根據(jù)礦井的涌水量和水壓選擇以疏排為主,還是以堵排為主。朱村礦54區(qū)一5煤底板距L2灰10252117 m,平均1576 m,由于局部地區(qū)地質(zhì)條件復(fù)雜,水壓較大,底板注漿比較困難,采取以疏排為主、帷幕注漿為輔的方法,開采前在斷層附近預(yù)注漿,并打鉆孔排水,以降低水壓,確保安全生產(chǎn)。采用這種方法后,54002工作面在開采過程中,基本上未發(fā)生過突水事故,達(dá)到了安全生產(chǎn)的目的。對場地進(jìn)行了填洼整平,既不占用農(nóng)田,又解決了場地?cái)U(kuò)建問題,保證了施工圖設(shè)計(jì)質(zhì)量。平頂山市衛(wèi)東區(qū)某煤業(yè)有限公司技改設(shè)計(jì)工業(yè)場地防洪與排澇設(shè)計(jì)中,設(shè)計(jì)按規(guī)范規(guī)定礦井井口防洪標(biāo)準(zhǔn)設(shè)計(jì)重現(xiàn)期為100 a,校核重現(xiàn)期為300 a,工業(yè)場地防洪標(biāo)準(zhǔn)設(shè)計(jì)重現(xiàn)期為100 a。防洪設(shè)計(jì)高程也按重現(xiàn)期的計(jì)算水位(包括壅水和風(fēng)浪襲擊高度)加安全高度進(jìn)行了計(jì)算,并以校核標(biāo)準(zhǔn)檢驗(yàn),按二者的大值確定。但在現(xiàn)場深入細(xì)致的調(diào)查中發(fā)現(xiàn),該礦井井田的南部為平煤集團(tuán)鐵路專用線,鐵路路基比正常地面高10余m,排洪涵洞斷面較小, 700 m范圍內(nèi)只有1個(gè), 1998年與該礦井鄰近的小煤礦遭遇重現(xiàn)期為50 a的洪水,因山洪暴發(fā),枯樹等雜物堵塞排洪涵洞,鐵路路基形成攔水壩,洪水回灌,以致井口灌水,形成淹井事故。根據(jù)調(diào)查了解的情況,對原設(shè)計(jì)方案進(jìn)行了優(yōu)化,通過技術(shù)分析和多方案比較,適當(dāng)加高了防洪設(shè)計(jì)高程,在井田范圍外距涵洞口30m處設(shè)置鋼筋篦子攔截雜物,并對排洪涵洞進(jìn)行清挖處理,保證了礦井安全,也避免了多余投資。(3)管路布設(shè)。井下通信線路、壓風(fēng)管路、消防灑水管路在安裝、施工設(shè)計(jì)時(shí)即按煤炭工業(yè)礦井設(shè)計(jì)規(guī)范進(jìn)行設(shè)計(jì),實(shí)際施工時(shí)也按此要求。2007年7月底發(fā)生的河南陜縣支建煤礦透水事故中,正是因?yàn)橛辛藭惩ǖ耐ㄐ啪€路、壓風(fēng)管路的給氧送風(fēng)、消防灑水管路輸送的牛奶面湯和科學(xué)施救措施,才挽救了69位礦工的生命。5.3重視對計(jì)算成果和過程的合理性分析在對中小煤礦技改工程設(shè)計(jì)中,對有關(guān)的計(jì)算成果和計(jì)算過程一定要進(jìn)行定性、定量分析,對使用各種公式的應(yīng)用條件要進(jìn)行分析,因?yàn)檫@些計(jì)算參數(shù)、使用公式應(yīng)用條件的選擇是否恰當(dāng),是否符合所應(yīng)用工程的具體條件,會(huì)直接影響到設(shè)計(jì)成果的合理性。如,礦井提升絞車的選型設(shè)計(jì)中,提升能力的計(jì)算規(guī)定較多,且規(guī)范用語以“不宜”、“不應(yīng)”較多,有時(shí)提升容器的質(zhì)量及鋼絲繩直徑的選擇也會(huì)影響提升絞車選型計(jì)算設(shè)計(jì)的結(jié)果。因此,地方中小煤礦技改工程的設(shè)計(jì),除嚴(yán)格執(zhí)行設(shè)計(jì)規(guī)范和各類煤礦規(guī)范規(guī)定外,還必須在設(shè)計(jì)前對每一項(xiàng)計(jì)算成果和參數(shù)進(jìn)行合理性分析和檢查,必要時(shí)應(yīng)進(jìn)行重新計(jì)算和核定,才能保證施工圖設(shè)計(jì)文件的質(zhì)量,為工程施工提供正確、安全、合理的數(shù)據(jù)。5.4不斷學(xué)習(xí)和積累專業(yè)知識(shí),提高綜合能力專業(yè)技術(shù)水平和工作能力的提高,離不開持續(xù)學(xué)習(xí)和經(jīng)驗(yàn)的積累。在中小煤礦技改工程設(shè)計(jì)和施工中,由于煤礦工程涉及面廣,設(shè)計(jì)人員應(yīng)熟練掌握煤炭工業(yè)設(shè)計(jì)規(guī)范、煤炭工業(yè)礦區(qū)設(shè)計(jì)規(guī)范、煤炭工業(yè)小型礦井設(shè)計(jì)規(guī)范、煤炭工業(yè)礦區(qū)機(jī)電設(shè)備修理設(shè)施設(shè)計(jì)規(guī)范、煤礦井下消防、灑水設(shè)計(jì)規(guī)范、煤礦安全規(guī)程等現(xiàn)行的煤礦規(guī)范規(guī)程,對即將實(shí)施的煤礦規(guī)范也應(yīng)認(rèn)真學(xué)習(xí),如煤礦井底車場硐室設(shè)計(jì)規(guī)范、煤礦斜井井筒及硐室設(shè)計(jì)規(guī)范、煤礦井下熱害防治設(shè)計(jì)規(guī)范、煤礦井下供配電設(shè)計(jì)規(guī)范等,還需加強(qiáng)對工程力學(xué)、結(jié)構(gòu)力學(xué)等專業(yè)知識(shí)的學(xué)習(xí),加強(qiáng)對工業(yè)及民用建筑等方面行業(yè)規(guī)范(如荷載設(shè)計(jì)規(guī)范、結(jié)構(gòu)設(shè)計(jì)規(guī)范規(guī)定)的學(xué)習(xí)。例如,平頂山市郟縣某煤業(yè)有限公司主井井底車場工程、地面主井絞車房工程都進(jìn)行了全面的受力計(jì)算,才確保工程設(shè)計(jì)有了可靠的依據(jù),彌補(bǔ)了原施工圖設(shè)計(jì)的缺陷,保證了工程設(shè)計(jì)、施工的質(zhì)量。這得益于對專業(yè)知識(shí)的強(qiáng)化學(xué)習(xí)和掌握。因此,從事煤礦工程設(shè)計(jì)和施工的技術(shù)人員不但要有扎實(shí)的專業(yè)知識(shí),而且還要熟悉和掌握有關(guān)門類的專業(yè)知識(shí)和規(guī)范。只有這樣,才能保證煤礦工程從設(shè)計(jì)到施工符合實(shí)際情況,少出問題,多出優(yōu)良工程。6 結(jié)語我國存在著嚴(yán)重的煤礦底板突水問題，頻繁發(fā)生的突水事故嚴(yán)重威脅著煤礦的安全生產(chǎn)運(yùn)。采取合理的預(yù)測方法和相應(yīng)的防治技術(shù)措施，才能有效地預(yù)防和控制底板突水事故的發(fā)生。參考文獻(xiàn)：1趙陽生，胡耀青著，承壓水上采煤理論與技術(shù)，煤炭工業(yè)出版社，20042白海彼，陳忠勝，鄭步連，葛均剛，奧灰隱伏陷落校特大突水的水源判別及治理。煤炭工程師No6，19983卜昌森礦壓作用下地質(zhì)構(gòu)造對底板突水的影響山東煤炭科技1996.14I高延法，李白英受奧灰承壓水威脅煤層底板變形破壞規(guī)律研究J。煤炭學(xué)報(bào)，2000,255胡耀青，趙陽升，楊棟等。礦區(qū)突水監(jiān)控理論及模型J。煤炭學(xué)報(bào)，2000,2（3）翻 譯 部 分英文原文Study on mining the protective seam with the manless working face in coal and gas outburst minesFang Xin-qiua,b, Zhao Jun-jiea,b, He Jiea,b, aSchool of Mines, China University of Mining & Technology, Xuzhou 221116, China bState Key Laboratory of Coal Resources and Safety Mine, Xuzhou 221008, ChinaAbstract: In order to solve the problems of backward equipments, low recovery, security issues, high mortality in the coal industry, the technology of manless working face in mine which combined the traditional mining process with the automatic technology is proposed based on the scientized mining, meanwhile, the idea of exploiting the protective seam in the coal seam group of the coal and gas outburst mines with manless working face technology is also proposed so as to liberate other high gas coal seams. Then, making the third coal seam in Shaqu coal mine which is a coal and gas outburst mine as the protective seam was being exploited and carried out the designs which included roadway, equipments selection and mining process. Finally, based on the theoretical analysis and numerical simulation, the gas extraction arrangements is designed, which provides the scientific basis and method for industrial experiment of the third coal seam. Key words: scientized mining; coal seam group; protective seam; manless working face; gas extraction1. IntroductionThe scientized mining means mining the coal with the highest efficiency on the precondition of safety and environment friendly 1. Chinas coal output is very big, the advanced mining machines must be used in order to adapt to the construction of modern mine, furthermore, the manless working face should also be used in some difficult conditions such as thin coal seam or coal and gas outburst seam. Although the mining technology develops rapidly, the overall level is still relatively backward. In order to solve this problem, change the present situation and keep the sustainable development of coal resources 2, the author proposes that the protective seam is mined with the manless working face in the coal and gas outburst mines. Then other high-gas coal seams can be liberated and the gas concentration can also be decreased, so there will be a safe condition for mining. Finally, the safe and high efficient green mining will be achieved 3.2. Mining the protective seam in high outburst minesThe coal seam group is one character of the high gas mining area in china and the permeability of coal seam is very low 4. Therefore, gas is the primary factor which prevents this kind of mines from safety and high efficiency.The protective seam mining is widely used in these high outburst mines in China so as to solve this problem. In addition, this is the most scientific method to prevent the regional gas outburst under the condition of mining the coal seam group in high outburst mines 5, 6.When there is a coal seam group in the gas outburst mine, the no-outburst seam or little-outburst seam will be firstly exploited, and this kind of coal seam is called the protective seam. The original equilibrium state of stress will be broken after the protective seam is exploited. Besides, with the development of roof and floor, the strata stress will be redistributed. The roof strata can be divided into caving zone, fractured zone, and bending zone 7, the floor strata will generate floor heave and fractures 8. The fractures contain bedding joint and cross-fracture, the degree of the fracture development of the floor is in inverse proportion to the spacing of layers. The methods of gas extraction can be classified as short distance, medium distance and long distance through the relative spacing of layers which is based on the concrete geological conditions of the coal mines 9, which provides a theoretical guidance to the gas control of coal seamgroup. The practice of mining the protective seam shows that the gas permeability of the upper outburst-relieved seam increases 1000-3000 times, while that of the lower outburst-relieved seam increases about 1000 times. This provides a good chance for gas extraction. So the effect of the increased gas permeability should be fully utilized to extract the gas by arranging kinds of drillings or roadways which not only ensures the safety of mines but also guarantees the extracted green and efficient gas energy for industry. Then the simultaneous extraction of coal and gas can be realized. The concrete methods are as follows:(1) Extracting the gas by ground surface drilling. This method is applied successfully in America 10, besides,Huainan, Huaibei, and Tiefa mining bureaus also made some tests or applications 11. Although they have got some effect, the stability of the drillings are not very well so that they are broken before the expected life for the different geological conditions between China and America and the influence of the movement of the overlying strata.(2) Arranging some drillings and roadways in the coal seam or strata to extract the gas which is the main method widely used in solving the gas outburst problem.3. Analysis of the feasibility and application in manless working face3.1. Analysis of the feasibilityThe modern manless working face is proposed with the principle of scientized mining and comprehensive utilization of coal resources 12. Based on the concrete conditions of China, we analyze the feasibility of manless working face:The gas emission of the thick and medium-thickness coal seam is more thinner than coal seam, so the thin coal seam is the first choice as protective seam. At present, although the mining degree of chanization and automationin thick and medium-thickness coal seam is relatively high, but in thin coal seam is relatively backward. Blasting mining is the main method of mining the thin coal seam, on the one hand, the mining production rate is low and the partial coal resource is lost 13. On the other hand, the working environment is bad and the labor intensity is big.Considering these unfavorable factors, many coal mines give up exploiting the thin coal seams. This action not only wastes the coal resources seriously but also shortens the service life of the mines, meanwhile, it also restricts the development of the protective seam in the coal seam group of the coal and gas outburst mines. So the urgent affair in mining field is to develop the high yield and high efficiency mining technology.Based on the system model of the manless working face, we make some integrated innovations on the modern technology and analyze the needed technology of every subsystem such as self-positioning and automatic navigationtechnology of the shearer, automatic vertical steering technology of the shearer, automatic recognition technology between coal and strata, electro-hydraulic control technology of the hydraulic support, automatic traction technology of the scraper conveyor, two-way communication technology of high-speed in the underground, component based coalmine software as well as the model technology, database technology and multi-sensor technology.After being combined with these technologies, the manless working face technology can greatly improve the mining rate and promote the security.Coal is the main energy resource in China, the healthy development of the coal industry is related to the energy security and economic sustainable development of China. The coal is non-renewable resource and the service life of the mine is certain. If the thin coal seam can be exploited through the existing production system, the recoverable reserves will be increased, and then the economic benefit will also be increased.At present, gas explosion has the highest proportion in all kinds of the coal mine accidents in China. There were 182 coal mine accidents in 2008, the death toll was 778. So the preventing of gas accidents shoulders heavy responsibilities.3.2. ApplicationBased on the scientific mining, exploiting the protective seam with manless working face is proposed combined with these analyses in coal seam group of the coal and gas outburst mines. After the gas in the coal seam group is released, it can be extracted by the reasonable drillings. It is a win-win method, not only will the frequent gas overrun, frequent gas accidents and the limitation of scale be solved, but also the problems of great difficulty in mining and low mining rate. Furthermore, the green mining of coal resources can be realized by simultaneousextraction of coal and gas.4. Example of mining designs in manless working face4.1. Condition of text areaThe Shaqu coal mine of the HUAJIN coking-coal company is a coal and gas outburst mine. The absolute outflow of gas is 344.43 m3/min and the relative outflow of gas is 61.8 m3/t. It is a short distance coal seam group and the minable seams are the second, third, forth and fifth coal seam (Fig.1).Fig. 1. Columnar section of coal and strata seamThe article 193 of coal mine safety regulation prescribes that the protective seam should be exploited preferentially when mining the coal seam group in coal and gas outburst mine. The article 198 prescribes that the gas of liberated seams should be extracted when mining the protective seam 14. So the Shaqu coal mine constitutes the regional gas government which the third coal seam is mined to liberate the second and third coal seam in order to guarantee the safety and efficient mining.4.2. Design of the working faceThe 13301 working face of Shaqu coal mine is chosen as the experimental area where U-type ventilation is designed in line with reducing the amount of roadway as well as decreasing the gas concentration. In order to extract the gas of 13301 working face, the inclined dense drillings are bored in the return airway by the ADR 250 High-Efficiency drilling rig (Fig.2).Fig. 2. Schematic diagram of gas extracting drilling in 13301The aperture of the drilling rig is 250 mm and its very rare home and broad. The big aperture which is beneficial to extract the gas can greatly improve the extraction rate. The length of the working face is 150 m and the length of the drilling is 140 m, arranging the drilling every 6 m in the direction of tendency and all the drillings are parallel.The distance between open-off cut and the first drilling is 15 m and the last one is at the stopping line, so there are altogether 160 drillings. Using the spiral-welded steel pipe as the main pipe which is laid along the floor and UPVC as the branch pipe which is suspended from the roof, the size of the former is DN820mm12mm and the latter is D225mm10mm. The connection model is flange joint.The shape of the roadway is rectangle using the combined support of anchor, metal net and W-type steel band to support the roadway. Both the width of the conveyance roadway and return airway is 4.5 m, the height of the roadway is 2.8 m.4.3. Selection of the equipments in the working faceChoice of shearerFully automatic mining system of the plough is an effective way to realize high production and efficient 15. The features of little depth-web, fast advance speed and high adaptability make it the first choice in mining the thin coal seam. In order to realize the high production, high efficient and high automation, the GH9-34ve/4.7 plough of the DBT Company is selected combined with the concrete conditions in Shaqu coalmine. The rated power of this plough is 160/315 kW and the production capacity is 900 t/h. It can meet the requirement of high production and high efficient.Choice of hydraulic supportFollowing the principle of reliable system and the priority of domestic equipment, we select the Germany PM4 control unit combined with the domestic hydraulic support. The concrete type is ZY4800/6.5/16.5D of the middle hydraulic support and ZZ5800/16/30 of the terminal hydraulic support. Choice of scraper conveyorThe current proportion between the scraper conveyor and shearer is 1.21.4:1. In order to exert the capacity of the scraper conveyor, we select the PF2.30/732 scraper conveyor.The capacity of the fully mechanized mining equipments should be based on the capacity of the shearer.Meanwhile, the principles of the speed-matching, connection-matching, etc. should also be taken into consideration.Then the main equipments of the working face can be determined (Table 1).Table 1. Main equipments of the working faceEquipment nameTypePloughGH9-34ve/4.7scraper conveyorPF2.30/732Middle hydraulic supportZY4800/6.5/16.5DTerminal hydraulic supportZZ5800/16/30Transfer machineSZZ764/132CrusherPEm1000650Belt conveyorSSJ1200/m4.4. Mining technologyBy means of the combined auto-control shearer and hydraulic support, the automatic coal cutting, automaticadvancing support and the linkage of the scraper conveyor can be realized, meanwhile, using the centralized control and sequential start-stop to realize the automatic control (Fig.3).Fig. 3. Technological process4.5. Design of gas extraction4.5.1. Numerical simulationThe numerical simulation software UDEC is adopted to provide the theoretical basis for the gas extraction so that the gas outburst of the first mining seam and the contiguous seams can be governed well. Taking the strike sectionof the 13301 working face as field model, then, the numerical model can be built length of tendency length of inclination=25055 m, the elevation of the third coal seam is 450 m. The left hand, right hand and lower boundaries of the model are displacement boundary. The left and right boundaries constrain the displacement in x-direction and the lower boundary constrains the displacement in y-direction (Fig.4).Fig. 4. Simulation modelThe change law of the mining influence, height of fractured zone in the roof and floor and the change law of fractured zone with the advancing of working face are simulated in this numerical simulation. The results are as follows:When the advance distance is 40 m (Fig.5), basic roof begins to collapse. The height of the caving zone is about 6m and the strata near basic roof are destroyed by tension. The vertical fracture and interlayer fracture are generated in the overlying strata and the height of breaking though fracture is about 10 m. There is some deformation in floor of the goaf, which can be seen from the displacement curve of the floor that the maximum compression deformation is 7 m around the lateral of cutting hole and 7 m around the front of the working face. The maximum floor heave deformation is 5 m around the medial of the cutting hole and 5 m around the rear of the goaf. The maximum deformation is 30 mm. When the advance distance is 60 m (Fig.6), the overlying strata and floor strata are destroyed by the interaction of principal stress and shear stress, moreover, the vertical fracture and interlayer fracture develop constantly. With the advancement of the working face, interlayer fracture is the main fracture above the basic roof of the goaf. The main range of vertical fracture is 5 m away from the roof and floor.Fig. 5. Movement status and fracture distribution of surrounding rock (a) when the excavation distance is 40 m; (b) when the excavation distance is 60 m4.5.2. Design of the gas extraction arrangementIt can be obtained from the theoretical analysis and numerical simulation that the second coal seam is in the fractured zone of the third coal seam and the forth coal seam is in the deformation zone of the third coal seam. So the gas can be largely extracted after arranging some drillings in the fractured zone of the roof and deformation zone of the floor.The DDR1200 directional drilling rig which introduced by the Shaqu coal mine can be controlled artificially to drill along the roof or floor at some angle. The aperture is 170 mm and the drilling length is 1200 m. The 13301 working face is selected as the experimental area and the concrete schemes are:Four drillings were born when they reached the forth coal seam, then, boring in the forth coal seam. These drillings can extract the pressure relief gas of forth coal seam and the gas between the third and the forth coal seam.Four drillings were born when they reached the upside of the second coal seam and the vertical distance between the second coal seam and the drillings is 3 m, then, bore along the direction of parallel to second coal seam.So the second coal seam can be liberated. The profile drawing of the drillings is shown in Fig.7.So the coal seam group can be liberated and the problem of gas outburst can also be well solved.Fig. 7. Schematic diagram of profile in 133015. ConclusionsThe problems of coal mining in China are researched and the manless working face is proposed, which is based on the automatic conditions of fully mechanized mining coal face ,It is an important way to realize the sustainable development of coal industry.The idea of mining the protective seam with the manless working face in the coal seam group of the coal and gas outburst mines is proposed. Not only the problem of hard-mining in coal and gas outburst mines will be solved but also the problem of hard-mining in thin coal seam can be solved.Working face design, equipments selection and mining technology design are carried out to the third coal seam based on the concrete conditions of the Shaqu coal mine.Feasibility of making the third coal seam as protective seam is verified based on the theoretical analysis and numerical simulation and it provides a new thought to the safe and high efficient coal mining.AcknowledgementsFinancial support for this work, provided by the National Natural Science Foundation of China, is gratefully acknowledged.References1 M.G. Qian, On scientized mining. Journal of Mining & Safety Engineering. 25 (2008) 1-10.2 L.S. Shi, Analysis of Chinas energy and development plan of renewable energy. Policy and Management. 117 (2005) 1-4.3 M.G. Qian, X.X. Miu and J.L. Xu, Resources and environment harmonics (green) mining and its technological system. 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