開灤礦業(yè)集團有限責(zé)任公司呂家坨東礦1.5Mta新井設(shè)計【含CAD圖紙+文檔】
開灤礦業(yè)集團有限責(zé)任公司呂家坨東礦1.5Mta新井設(shè)計【含CAD圖紙+文檔】,含CAD圖紙+文檔,開灤,礦業(yè)集團,有限責(zé)任公司,呂家坨東礦,mta,設(shè)計,cad,圖紙,文檔
翻
譯
部
分
附錄1：資料原文
淺析煤礦深井開采礦壓顯現(xiàn)規(guī)律與控制
摘 要：開采深度的增加是礦井生產(chǎn)的自然規(guī)律，隨之而產(chǎn)生巖石溫度增加，地壓增大，巖石破壞過程強化，巷道圍巖變形劇烈，沖擊地壓強度增大和頻度增加等自然現(xiàn)象。深部煤層開采復(fù)雜化的主要影響因素是礦山壓力，在高應(yīng)力作用下，圍巖移動更為劇烈，巷道產(chǎn)生變形和破壞也更為嚴重，巷道圍巖變形速度快、變形量大，巷道周邊變形范圍大；巷道對支架的工作特性要求高，初撐力、工作阻力和可縮量均大，即使開掘在底板巖石中的巷道，用拱形金屬支架和各種結(jié)構(gòu)封閉式支護的巷道有時也遭巨大變形。
關(guān)鍵詞：深井開采沖擊地壓巷道布置,深部開采,地溫,瓦斯,地壓
1 深部開采出現(xiàn)的問題
1.1 地溫增高
地溫增高是礦井開采深度增加時出現(xiàn)的突出問題之一。一般來說,開采深度每增加100 m ,巖石溫度增高3～5 ℃,在深度為1 000 m 時,地溫達30～50 ℃。我國保安規(guī)程定,采掘工作面的最高溫度不超過26 ℃,同時規(guī)定采掘工作面氣溫超過30 ℃,機電峒室的氣溫超過34 ℃,必須采取降溫措施。目前,堿場和雞東兩礦向下延深,都面臨溫度超限問題,堿場煤礦目前的巖石溫度已達2415 ℃。每延深100 m增溫4 ℃,預(yù)計開采深度超過700 m 時,工作面的溫度將達到保安規(guī)程規(guī)定的26 ℃極限,因此,向深部延深時應(yīng)注意溫度的變化。
1.2 瓦斯涌出量增加
開采深部井田時,瓦斯涌出量一般比較大,但又不完全受開采深度的影響,經(jīng)常與煤層賦存條件和地質(zhì)構(gòu)造有關(guān),在不同礦區(qū)有很大差別。堿場礦資料表明(見圖1) ,隨著開采深度的增加,瓦斯涌出量增大,但開采深度超過400～500 m以后,瓦斯涌出增長趨緩或不再增長。堿場煤礦一井最大瓦斯涌出量達到66 m3/ t·d ,開采深度為500～600 m ,分析認為主要受到深部的斜交向斜及斷層帶的影響,超過600 m 深度時,瓦斯涌出量急聚下降,預(yù)計向深部開采瓦斯涌出量將穩(wěn)定在40～50m3/ t·d ,緩慢地增長。資料還說明,堿場礦先采2下煤層或3 # 煤層,兩煤層為非近距煤層,對瓦斯涌出量的影響不大,說明兩煤層之間瓦斯?jié)B透性較差。雞東礦資料顯示,礦井集中生產(chǎn),開采強度加大,產(chǎn)量增加,瓦斯涌出量有下降的勢頭,同時也顯示,當(dāng)煤層間距超過50 m 以上時,煤層之間的瓦斯?jié)B透性很小,作為解放層開采效果不會太好。礦井向深部開采至700～800 m 深時,由于受近似于走向一級褶曲的影響,瓦斯涌出量可能急聚增大。
1.3 礦山壓力
礦山壓力增大也是礦井深部開采中普遍出現(xiàn)的問題之一,特別表現(xiàn)為開拓巷道的圍巖變形量增加,維護困難。據(jù)國外一些觀測和研究結(jié)果,開采深度每增加100 m ,巷道頂?shù)装逡平吭黾? % ,巷道維護困難,特別是圍巖松軟時更為突出。變形量主要來自底鼓,所以隨著開采深度的增加,巷道斷面也就應(yīng)逐漸加大。
2. 煤礦深井巷道礦壓顯現(xiàn)特點
2.1巷道變形量大
深井巷道礦壓顯現(xiàn)的顯著特點之一是巷道開挖就產(chǎn)生大的收斂變形量。這一特點是由深井巷道圍巖處于破裂狀態(tài)和深井巷道圍巖有較大的破裂范圍決定的。
蘇聯(lián)的研究表明，隨開采深度加大，巷道變形量呈近似線性關(guān)系增大，從600m 開始，開采深度每增加100m，巷道頂?shù)装逑鄬σ平科骄黾?0％～11％[2]，如圖1 所示。理論分析表明，深部開采的巷道變形量隨開采深度增大呈近似直線關(guān)系增大，如圖2 所示，開采深度每增加100m 的巷道變形增量與巖體強度有關(guān)。
1-σc=3.8MPa， σc*=0.2MPa， φ=25°，k=1 ；
2-σc=9.8MPa， σc*=0.49MPa， φ=30°，k=1
國內(nèi)外深部開采的實踐表明，開采深度為800～1000m時，巷道變形量可達1000～1500mm甚至更大，與開采深度和巖石力學(xué)性質(zhì)(破裂區(qū)厚度)等因素有關(guān)。由于深井巷道變形量大，若支護不合理(如采用剛性支架或支架的可縮量不足)時，巷道變形、破壞嚴重，因此，深井巷道的維修工作量大，維護費用高。實踐表明，深部開采的巷道翻修率(損壞率)可達40％～80％(部分是由于支護不當(dāng)造成的)，甚至高達100％,與開采深度、巖石力學(xué)性質(zhì)、支護方式、支架力學(xué)性能與參數(shù)，特別是可縮量等有關(guān)。
2.2掘巷初期變形速度大
深井巷道礦壓顯現(xiàn)的另一個顯著特點是，巷道剛掘出時的變形速度很大。根據(jù)現(xiàn)場觀測表明，深井巷道剛開挖時的變形速度可達50mm/d以上。觀測巷道為趙各莊礦13 水平東翼階段運輸巷(現(xiàn)場稱為電車道)，埋深1159m，圍巖為煤至半煤巖，錨噴網(wǎng)支護。巷道掘出后，變形速度隨時間的延續(xù)呈負指數(shù)曲線急劇衰減，經(jīng)過一定時間后趨于穩(wěn)定，如圖3 所示。巷道收斂變形主要是由于處于殘余強度狀態(tài)的破裂區(qū)圍巖破裂膨脹變形的結(jié)果。因此，深井巷道變形速度的上述規(guī)律表明：
（1）巷道圍巖破裂區(qū)的形成經(jīng)歷了一個時間過程(此時間過程的長短與圍巖破裂范圍即破裂區(qū)厚度有關(guān))；
（2）深井巷道圍巖破裂的發(fā)展速度在巷道剛開掘時較快，以后逐漸衰減，直至破裂區(qū)完全形成。
2.3變形趨于穩(wěn)定的時間長和長期蠕變
變形趨于穩(wěn)定要經(jīng)歷一個較長的時間過程是深井巷道礦壓顯現(xiàn)的又一大特點。從圖3可見，趙各莊礦13 水平東運輸大巷的變形穩(wěn)定期(變形趨于穩(wěn)定經(jīng)歷的時間)約兩個月。巷道變形穩(wěn)定期與圍巖破裂范圍大小有關(guān)——破裂區(qū)厚度越大，巷道變形穩(wěn)定期越長。雖然深井巷道開掘后要經(jīng)過較長時間變形才能趨于穩(wěn)定，但巷道的收斂變形大部分發(fā)生在開掘后較短的一段時間內(nèi)。掘巷引起的巷道圍巖變形趨于穩(wěn)定后，變形速度維持在一個較低水平。此后，巷道圍巖保持這一速度不斷變形，長時期處于蠕變狀態(tài)，直至受采動影響。
2.4巷道底臌量大
底臌量大是深井巷道礦壓顯現(xiàn)的又一個顯著特點。而且，從國內(nèi)外的有關(guān)報道看，深部開采的巷道底臌現(xiàn)象具有普遍性[3]。據(jù)蘇聯(lián)對部分深井資料的統(tǒng)計分析，底臌現(xiàn)象及底臌量與開采深度有很大關(guān)系：即隨開采深度增大，易于產(chǎn)生底臌的巷道比重越來越大，底臌量及其在頂?shù)装逑鄬σ平恐兴嫉谋戎仉S開采深度增大而增大。
2.5沖擊地壓發(fā)生的頻率和強度增大
理論研究和生產(chǎn)實踐都表明，礦山?jīng)_擊地壓的發(fā)生、發(fā)生的頻率和沖擊強度與開采深度有密切的關(guān)系。隨開采深度增加，煤、巖體因變形而積聚的能量呈二次方關(guān)系增加。因此，在深部開采條件下，煤、巖體中積聚了巨大的能量，當(dāng)采礦活動引起的能量釋放速度大于煤、巖體破壞消耗的能量速度時，導(dǎo)致沖擊地壓的發(fā)生。實踐表明，深部開采發(fā)生沖擊地壓的頻率大大增加，沖擊的強度顯著增大。深部開采的沖擊地壓問題在巖體強度較大的礦山更為突出。
3. 煤礦深井回采工作面礦壓顯現(xiàn)特點
3.1老頂?shù)某醮蝸韷?
當(dāng)老頂達到極限跨距而且斷裂時形成三鉸拱式的平衡以后，隨著工作面繼續(xù)推進，將導(dǎo)致新巖塊A 的斷裂，如圖4 所示。此時由于巖塊A 的力矩之和ΣM0≠0，迫使巖塊A 發(fā)生回轉(zhuǎn)。老頂?shù)氖Х€(wěn)將對工作面帶來嚴重的礦山壓力顯現(xiàn)，甚至危及生產(chǎn)和人身安全。因此，把由于老頂?shù)谝淮问Х€(wěn)而產(chǎn)生的工作面頂板來壓稱為老頂?shù)某醮蝸韷骸?
當(dāng)老頂巖塊失穩(wěn)時，形成了巖塊滑落，對工作面安全造成嚴重威脅。由于老頂破斷巖塊回轉(zhuǎn)的影響，工作面頂板必然發(fā)生下沉?；夭晒ぷ髅婷罕谏纤惺艿闹С袎毫㈦S著老頂跨度的加大而增加。即剛從開切眼推進時為最小，在初次來壓前則達到最大。由于煤壁前方強大的支承壓力，可能導(dǎo)致直接頂在煤壁前方形成剪切破壞，從而形成頂生裂隙。這對回采工作空間的頂板管理顯然也是不利的。
老頂初次來壓比較突然，來壓前回采工作空間上方的頂板壓力比較小。初次來壓時，老頂跨距比較大，影響的范圍也比較廣，工作面易出現(xiàn)事故。
3.2老頂?shù)闹芷趤韷?
老頂初次來壓后，回采工作面繼續(xù)推進，裂隙體梁所形成的結(jié)構(gòu)將發(fā)生以下變化。如圖5 表示了這個變化過程。由圖中a 進入b，A 巖塊將由穩(wěn)定狀態(tài)進入斷裂狀態(tài)。此時，按結(jié)構(gòu)的自由度計算，結(jié)構(gòu)將進入不穩(wěn)定狀態(tài)。隨著回采工作面的推進，在老頂初次來壓以后，裂隙帶巖層形成的結(jié)構(gòu)，將始終經(jīng)歷“穩(wěn)定—失穩(wěn)—再穩(wěn)定”的變化[3]。這種變化將呈現(xiàn)周而復(fù)始的過程。由于結(jié)構(gòu)的失穩(wěn)導(dǎo)致了工作面頂板的來壓。這種來壓也將隨著工作面的推進而呈周期性出現(xiàn)。因此，由于裂隙帶巖層周期性失穩(wěn)而引起的頂板來壓現(xiàn)象稱之為工作面頂板的周期來壓。
周期來壓的主要表現(xiàn)形式是：頂板下沉速度急劇增加，頂板的下沉量變大；支柱所受的載荷普遍增加；有時還可能引起煤壁片幫、支柱折損、頂板發(fā)生臺階下沉等現(xiàn)象。如果支柱參數(shù)選擇不合適或者單體支柱穩(wěn)定性較差，則可能導(dǎo)致局部冒頂、甚至頂板沿工作面切落等事故。
4 礦井深部開采通常的技術(shù)措施
4.1 降溫措施
一般情況主要降溫措施為增大風(fēng)量和改變通風(fēng)系統(tǒng)。我國安全規(guī)程規(guī)定,回采工作面的風(fēng)速不超過410 m/ s ;為加大風(fēng)量,相應(yīng)地增加回采工作面的最小通風(fēng)斷面。增加回采工作面的風(fēng)量,除了保證回采工作最小通風(fēng)斷面外,更主要的是礦井要有足夠的通風(fēng)能力;回采工作面進回風(fēng)道要有足夠的通風(fēng)斷面。將常用的U 型通風(fēng)系統(tǒng)改為Y型或W型通風(fēng)系統(tǒng)。Y型通風(fēng)系統(tǒng)可大量增加工作面進風(fēng),降溫效果明顯,但須增一條采區(qū)邊界回風(fēng)道和保護一條回采工作面上回風(fēng)道,在目前地溫并不太高的情況下,采用W 通風(fēng)系統(tǒng)可有效提高工作面供風(fēng)能力,降低回風(fēng)溫度。
4.2 防治瓦斯及瓦斯突出措施
防治瓦斯除通常采用加大風(fēng)量、提高風(fēng)速以外,還有開采上部或下部解放層釋放瓦斯;采取抽放瓦斯措施并對瓦斯加以利用;采取煤層注水用以改變煤的物理力學(xué)性質(zhì),降低瓦斯應(yīng)力。
對于開采深部瓦斯涌出量大的礦井,采用通常U 型通風(fēng)系統(tǒng)時,經(jīng)常出現(xiàn)回風(fēng)流中瓦斯超限、瓦斯積聚、工作面和巷道中風(fēng)速過大問題,并且使采區(qū)漏風(fēng)量較大。為此,國內(nèi)外近年來試行了采區(qū)內(nèi)改用直線通風(fēng),工作面下行通風(fēng),及Y型、Z 型、W型通風(fēng)系統(tǒng),除了可以有效地沖淡瓦斯、減小風(fēng)速、避免瓦斯積聚、降低工作面溫度外,還可以減少含塵量,有利于提高工作面產(chǎn)量。與上行通風(fēng)系統(tǒng)相比,工作面回風(fēng)流瓦斯可降低20 %～50 % ,工作面溫度降低2～5 ℃,煤塵減少十余倍,工作面產(chǎn)量可提高50 %～100 %。采區(qū)及工作面采用直線式通風(fēng)系統(tǒng),被認為是一種安全可靠性較高和經(jīng)濟效果較好的通風(fēng)系統(tǒng)。
4.3 減少巷道壓力措施
深部巷道地壓顯現(xiàn)主要表現(xiàn)在巷道掘進后圍巖在較長時間內(nèi)產(chǎn)生蠕變變形,使巷道支架承受很大的壓力。變形速度最快是在掘進后的10～15 天范圍內(nèi),瞬時蠕變的時間可達60～90 天,180 天后尚趨向穩(wěn)定。在礦壓大的情況下。采用錨桿和各種支撐式支架的混合支護方式能獲得較好的效果。單獨采用錨桿或發(fā)雙層料石碹解決深部巷道支架問題既無效又不經(jīng)濟。深部軟巖巷道變形區(qū),存在著塑性帶和松動帶,支護應(yīng)采用與圍巖共同作用的錨噴支護,而錨桿的長度要大于松動帶的深度。若錨桿深不足,應(yīng)采用噴錨網(wǎng)噴復(fù)合支護結(jié)構(gòu),并與外部支護聯(lián)合支護。礦壓大和有底鼓的軟巖巷道支護,國內(nèi)外都有采用爆破裂縫卸載和底板巖石加固的方法。
5. 煤礦深井巷道的礦壓控制
5.1優(yōu)化巷道布置
采準巷道的布置應(yīng)避開煤柱集中應(yīng)力、構(gòu)造集中應(yīng)力、采動應(yīng)力的影響,選擇在巖性較為穩(wěn)定的巖石中。深部采區(qū)主要準備巷道應(yīng)以巖巷為主或至少布置一條巖巷。隨著深度的增加,回采工作面推進后煤體塑性區(qū)增加,致使區(qū)段煤柱留設(shè)寬度隨之增加,為保證采區(qū)回收率,減少巷道維護,工作面回風(fēng)(運輸)平巷宜采用無煤柱護巷的形式。巷道施工在遇到以壓應(yīng)力為主的褶曲、逆斷層時,巷道方向盡量與褶曲軸或斷層走向垂直或斜交;在遇到以拉應(yīng)力為主的正斷層時,巷道方向則與斷層走向一致或斜交,從而達到減小礦壓顯現(xiàn)的目的?；夭上锏啦贾玫姆轿粦?yīng)使工作面離開斷層推進,使采區(qū)一翼內(nèi)工作面同向推進。避免巷道相向掘進和巷道近距離平行布置,減少相交巷道(或避開銳角),從而減小應(yīng)力集中,減少發(fā)生沖擊地壓的危險性。
5.2改革巷道支護形式
對國內(nèi)外大量深井開采礦井的研究表明，布置在中硬以下巖層中的巷道變形破壞嚴重（特別是受采動影響后），當(dāng)采深在800～1000m 以上時，在中硬及中硬以上巖層內(nèi)布置的巷道，若采用傳統(tǒng)的支護方式，巷道維護仍很困難[4]。因此，深井中，除要求合理布置巷道位置外，還應(yīng)根據(jù)深井礦壓特點，巷道支護必須滿足既能加固圍巖又能提供較大的支護力、具有較大的可縮性和一定的初撐力等要求，根據(jù)圍巖狀況和巷道條件，采用不同的支護形式。
目前，深井巷道應(yīng)采用的主要支護及控制措施有以下幾方面。
(1)在采準巷道中發(fā)展多種形式的U 鋼可縮性支架，是解決圍巖高應(yīng)力、大變形的有效支護形式。提高支架架設(shè)質(zhì)量，加強壁后充填，改善支架受力狀況。
(2)發(fā)展以錨桿為主體的新型支護，即錨噴支護、錨梁網(wǎng)組合支護、錨桿與可縮性支架聯(lián)合支護以及可縮性錨桿等。合理選擇支護形式和參數(shù)，加強質(zhì)量管理，完善檢測手段等是錨桿支護應(yīng)用的重要問題。
(3)針對采準巷道不同時期，采動影響引起的不同圍巖移動特征，采用改變巷道支護方式、調(diào)節(jié)巷道支護強度的非等強多次支護工藝，對改善深井巷道的技術(shù)經(jīng)濟效益有重要意義。
(4)錨噴網(wǎng)聯(lián)合支護在服務(wù)年限長，圍巖較穩(wěn)定的深井巷道中廣泛應(yīng)用，這一支護形式能充分發(fā)揮圍巖自承能力，防止水及空氣對圍巖的風(fēng)化作用。
6、煤礦深井回采工作面的礦壓控制
6.1深井回采工作面礦壓控制的特點
深部采場礦壓控制特點由深部采煤工作面頂板巖性變化特點和可能發(fā)生的冒頂事故類型決定。經(jīng)調(diào)查，深礦井開采煤層的頂板巖性變化隨著采深增加,頂板巖層有逐漸變碎和強度降低的趨勢；隨采深增加,斷層、裂隙、層理和節(jié)理逐漸發(fā)育,同一層位的巖層分層厚度逐漸變薄,弱面增多,采場頂板懸頂長度逐漸減小,由不容易垮落變得容易垮落；在頂板巖層變碎和強度有所降低的情況下,深井采場出現(xiàn)漏垮型冒頂事故的可能性加大[2]。
6.2深井回采工作面礦壓的控制措施
(1)對工作面前方已產(chǎn)生裂隙的煤、巖體,超前工作面注漿,注入樹脂類粘結(jié)劑,使其固化,提高煤巖體自身強度,保證其穩(wěn)定性；也可采用深孔樹脂錨桿加固頂板和煤壁。
(2)盡量縮小端面空頂距,減小無支護面積。若液壓支架前探梁有伸縮功能,更有利于新暴露頂板的及時維護,特別有利于片幫后裸露頂板的管理。
(3)提高前梁支撐力,及早地使支撐力與頂板壓力取得平衡,減小新暴露頂板的離層、撓曲機率。加強移架工序的管理,盡力減少破碎頂板的活動程度。
(4)對單體支柱工作面,頂梁上盡量鋪笆或金屬網(wǎng),若有漏頂,應(yīng)及時構(gòu)頂填實,以防頂板失控,導(dǎo)致支架的失穩(wěn)。
(5)要有合理的開采順序和回采方向,避免應(yīng)力疊加造成煤壁壓酥,頂板破壞。
(6)工作面上、下出口及上、下順槽超前支承壓力的應(yīng)力疊加帶,應(yīng)優(yōu)先選用穩(wěn)定性較好的十字鉸接頂梁支護系統(tǒng)。
(7)要踏實地做好測壓工作，掌握初次垮落、初次來壓、周期來壓步距、超前支承壓力的有害影響范圍、支柱載荷及巷道圍巖變形規(guī)律,以便針對性地做好量化管理。
7. 結(jié)論
（1）深井巷道礦壓顯現(xiàn)的顯著特點之一是巷道開挖就產(chǎn)生大的收斂變形量。這一特點是由深井巷道圍巖處于破裂狀態(tài)和深井巷道圍巖有較大的破裂范圍決定的。
（2）國內(nèi)外深部開采的實踐表明，巷道變形量與開采深度和巖石力學(xué)性質(zhì)(破裂區(qū)厚度)
等因素有關(guān)。
（3）深部開采發(fā)生沖擊地壓的頻率大大增加，沖擊的強度顯著增大。深部開采的沖擊地壓問題在巖體強度較大的礦山更為突出。
（4）避免巷道相向掘進和巷道近距離平行布置,減少相交巷道(或避開銳角),可以有效地減小應(yīng)力集中,減少發(fā)生沖擊地壓的危險性。
(5) 深部開采,巷道無論采取何種支護方式,巷道斷面的設(shè)計都應(yīng)考慮頂?shù)装宓囊平亢拖锏罃嗝娴氖湛s量;擴大巷道斷面和巷道高度,一般斷面增加20 %～35 % ,中高增加30 %以上。
(6) 減少圍巖變形量的有效措施。一是增加支撐強度。二是采用混合支護,如錨、支、錨、網(wǎng)、噴等支護方法。采用砌碹或雙層料石碹的效果不好。
(7) 混合支護時,要根據(jù)深部礦壓特點適當(dāng)掌握錨桿和支撐支護架設(shè)時間,才能起到良好作用。錨桿應(yīng)即時打,支撐支架及發(fā)旋碹應(yīng)在15～20 天以后進行。
(8) 巷道底鼓多采用爆破卸載或掏槽卸壓的方法,輔以灌水泥漿。
(9) 在生產(chǎn)過程中,應(yīng)認真研究礦井和采區(qū)對無煤柱開采與留煤柱開采主要參數(shù)的確定,通過實驗,不斷總結(jié)經(jīng)驗。
參考文獻
[1] 錢鳴高. 礦山壓力及其控制［M］. 煤炭工業(yè)出版社， 1991.3
[2] 錢鳴高，石平五. 礦山壓力與巖層控制［M］. 礦業(yè)大學(xué)出版社，2003.11
[3] 郭立，邵武等. 深井開采的巖石力學(xué)研究及工程應(yīng)用［J］. 礦冶工程. 2001 21(3) ：7-9
[4] 董隴軍，李夕兵等. 深井開采災(zāi)害應(yīng)對決策技術(shù)綜述［J］. 有色金屬. 2009 61(1) ：4-6
附錄2：原文
Of deep mining in coal and control of pressure behavior
Abstract: The increase of mining depth is the natural law of mine production, the attendant increase in rock temperature, ground pressure increases, the failure process of strengthening, deformation of surrounding rocks dramatic increase burst strength and frequency of natural increase of the phenomenon. Deep coal mining complex, the major factor is the ground pressure, high stress, the more violent surrounding rock, tunnel deformation and damage are more severe roadway deformation speed, large deformation, deformation of the surrounding roadway large range; roadway support the work of the characteristics of the high requirements, setting load, working shrinkage resistance and may have large, even digging the tunnel in the rock floor, with arched metal stand and support the various structures of the tunnel is sometimes closed has been a great distortion.
1 deep mining problems
Temperature increased 1.1
Temperature increase is the increase of mining depth, when one of the outstanding problems. In general, the mining depth for each additional 100 m, the rock temperature is increased 3 ~ 5 ℃, 1 000 m in depth, the ground temperature reached 30 ~ 50 ℃. Set of Security procedures, mining face the maximum temperature does not exceed 26 ℃, also provides for excavation working temperature than 30 ℃, mechanical and electrical chamber of the temperature exceeded 34 ℃, cooling measures must be taken. At present, the base field and the downward Jidong two deep mine, the temperature gauge problems are facing, base rock temperature field mine now reached 2415 ℃. Each extension 100 m depth temperature 4 ℃, the anticipated mining deeper than 700 m, the face of the temperature will reach 26 ℃ under security procedures limit, therefore, extend to the deep depth should pay attention to changes in temperature.
1.2 The increase in gas emission
When mining depth portion well field, the gas discharge quantity is quite generally big, but receives not completely mines the depth the influence, saves the condition and the geologic structure frequently with the coal bed tax related, has the very wide difference in the different mining area. The alkali field ore material indicated that (see Figure 1), along with mining depth's increase, the gas discharge quantity increases, but after the mining depth surpasses 400~500 m, the gas discharge growth becomes slower or no longer grows. An alkali field coal mine well biggest gas discharge quantity achieves 66 m3/td, the mining depth is 500~600 m, the analysis thought that mainly receives the depth portion the oblique syncline and the fault zone influence, when surpasses 600 m depths, the gas discharge quantity gathers anxiously the drop, estimated that will stabilize to the deep mining gas discharge quantity in 40~50m3/td, grows slowly. The material also explained that the alkali field ore picks 2 coal bed or 3
1.3 Ground pressure
The underground pressure increases is also one which of questions in the mine pit deep mining appears generally, displays specially for developing entry's adjacent formation amount of deformity increases, maintains the difficulty. According to the overseas some observations and the findings, the mining depth increases 100 m every time, the tunnel goes against the ledger wall to move to near quantity to increase 7%, the tunnel maintenance difficulty, the adjacent formation is specially soft when is more prominent. The amount of deformity mainly comes from the bottom drum, therefore along with mining depth's increase, the tunnel cross section should also enlarge gradually.
2. Coal Mine Roadway pressure behavior in deep
Roadway deformation exceeds 2.1
Deep Mine strata behavior is one of the significant features of tunnel excavation on the deformation produced large convergence. This feature is broken by the deep state and the surrounding rock in deep rupture roadway greater the scope of the decision.
Soviet studies show that with the increase of mining depth, roadway nearly linear relationship between the deformation increases, starting from the 600m, mining depth for each additional 100m, roadway floor closer to an average increase of 10% to 11% [2], shown in Figure 1. Theoretical analysis shows that deep mining of the tunnel deformation with the increase of mining depth was increased approximately linear relationship, shown in Figure 2, mining depth for each additional 100m of roadway deformation increment and rock intensity.
1-σc=3.8MPa， σc*=0.2MPa， φ=25°，k=1 ；
2-σc=9.8MPa， σc*=0.49MPa， φ=30°，k=1
The domestic and foreign deep mining's practice indicated that when the mining depth is 800~1000m, the tunnel amount of deformity may reach 1000~1500mm to be even bigger, with the mining depth and the rock mechanics nature (ruptured zone thickness) and so on factors concerns. Because the deep well tunnel amount of deformity is big, when supports and protects unreasonable (for example uses unyielding support or support may shrink quantity insufficiency), the tunnel distorts, the destruction to be serious, therefore, the deep well tunnel's service work load is big, the maintenance cost is high. The practice indicated that deep mining's tunnel reconditioning rate (damage rate) may reach 40%~80% (part is because supports and protects creates improper), even reaches as high as 100%, with the mining depth, the rock mechanics nature, the supports and protections way, the support mechanical properties and the parameter, specially may shrink the quantity and so on to concern.
2.2 digs lane initial period strain rate
(1) rupture of the Formation of the roadway through a time course (this time the length of the course and scope of the rupture zone broken rock thickness);
(2) the development of deep rupture rate of roadway in the tunnel when the just-dug faster, then gradually fading, until the rupture zone completely formed.
2.3 distortions tend the stable time long and long-term slow change
the distortion tend stable must experience a long time process are the deep well tunnel ore press the appearance another major characteristic. From Figure 3 obviously, east the Zhaogezhuang ore 13 levels transports the big lane's distortion stabilization period (distortion tends stable experience time) the approximately two months. The tunnel distortion stabilization period and adjacent formation breakage scope size related - - ruptured zone thickness is bigger, the tunnel distortion stabilization period is longer. Although after deep well tunnel digging, must pass through the long time to distort can tend to be stable, but tunnel's restraining distorts occurs majority of after digging in short period of time. After digging the lane to cause the tunnel adjacent formation distortion which tends stable, the strain rate maintains at a low level. Hereafter, the tunnel adjacent formation maintains this speed distorts unceasingly, the
2.4 Roadway large floor heave
Large amount of floor heave deep rock pressure is another show notable feature. Moreover, the reports from abroad to see, deep mining of opening floor heave phenomenon is universal [3]. According to Soviet data on some deep statistical analysis of the phenomenon of floor heave and volume of floor heave a great relationship with the mining depth: that with the increase of mining depth, easy to generate an increasing share of floor heave of the tunnel large amount of floor heave and its amount of roof and floor is relatively closer to the proportion with the increase of mining depth.
2.5 impact geostatic pressure occur the frequency and the intensity increase the fundamental research and the production practice indicated that the mine impact geostatic pressure's occurrence, occurs the frequency and the shock strength and the mining depth have the close relationship. Increases along with the mining depth, the coal, the rock mass because of distort the energy which agglomerates to assume the quadratic relations to increase. Therefore, under the deep mining condition, in the coal, the rock mass agglomerated the huge energy, when mining causes when the energy liberation speed is bigger than the coal, the rock mass destruction consumption energy velocity, causes the impact geostatic pressure the occurrence. The practice indicated that the deep mining has the impact geostatic pressure frequency to increase greatly, the impact intensity obviously increases. Deep mining's impact geostatic pressure question is more prominent in the rock mass intensity big mine.
3. The coal mine deep well stopping working surface ore presses appearance characteristic
3.1 The roof of the initial pressure
When the old roof and breaking the limit span of the formation of three-hinged arch when the balance after the advance to continue with the face, will lead to a new rock A's fault, shown in Figure 4. A rock at this time because the moment of and ΣM0 ≠ 0, force the rock A turn occurred. Unstable roof mines will face serious pressure behavior, and even endanger the production and personal safety. Therefore, the roof for the first time since instability arising from roof to roof as the initial pressure to pressure.
When always goes against the clod jitter, formed the clod to fall, posed the threaten seriously safely to the working surface. Because always goes against the breaking clod rotation the influence, the working surface roof has the submersion inevitably. On the stopping working surface coal wall withstands the force of support along with will always go against the span to enlarge increases. Namely just from opened cuts time the eye advancement to be smallest, before first presses achieves in a big way. Because front coal wall formidable force of support, possibly causes to go against directly forms the shearing failure front the coal wall, thus forms goes against lives the crevasse. This to the stopping working space's roof control is also obviously disadvantageous.
always goes against first presses is quite sudden, before presses, above the stopping working space roof pressure to be quite small. When first presses, always goes against the span to be quite big, the scope which affects is also quite broad,
3.2 always go against after the cycle presses
always goes against first presses, the stopping working surface continues to advance, crevasse body Liang forms the structure will have the following change. Like Figure 5 expressed this change process. A will enter the b, A clod by the chart to enter the break condition by the steady state. This time, according to the structure degree-of-freedom computation, the structure will enter the non-steady state. Along with stopping working surface advancement, after always goes against first presses, the crevasse belt rock layer forms the structure, will experience “the stable - jitter throughout - again stable” change [3]. This kind of change will present the process again and again. Because the structure jitter caused the working surface roof to press. This kind will press will also assume the periodicity along with the working surface advancement to appear. Therefore, the roof which causes as a result of the crevasse belt rock layer periodic jitter presses the phe
The cycle presses the main manifestation is: Roof-to-floor convergence speed sharp growth, the roof submersion quantitative change is big; The prop receives the load increases generally; Sometimes also possibly causes the coal wall cave-in of sides, the prop buckle, the roof to have phenomena and so on stair submersion. If the prop parameter choice inappropriate or the monomer prop stability is bad, then possibly causes the partial roof failure, even the roof to cut along the working surface falls and so on accidents.
4 deep mining usual technical measures
4.1 temperature decrease measure
ordinary circumstances main temperature decrease measure to increase the amount of wind and the change ventilation system. Our country safety regulation stipulated that the stopping working surface's wind speed does not surpass 410 m/s; In order to enlarge the amount of wind, increases the stopping working surface slightly to ventilate the cross section correspondingly. Increases the stopping working surface the amount of wind, is smallest besides the guarantee stopping work ventilates the cross section, what is main is the mine pit must have the enough well ventilated ability; The stopping working surface enters the air return way to have the enough well ventilated cross section. The commonly used U ventilation system will change Y or the W ventilation system. The Y ventilation system may increase the working surface to enter the wind massively, the temperature decrease effect is obvious, only want increases a working boundary air return way and protects in
4.2 prevention gas and gas prominent measure
the prevention gas besides usually uses enlarges the amount of wind, to enhance the wind
收藏