【正文】
the support system can easily bear the static load of gateway itself. With the working face advancing, the gateway begin to sense the dynamic action of the working face. When the distance between the face and monitoring area is around 20 meters, the deforming velocity of surrounding is increasing obviously and the strata is moving remarkably, such response of the gateway is the dynamic action of the working face. The testing results show that the reinforced distance should be more than 20 meters. However , from the overall status of the surrounding rock, the gateway is in stable conditions and can satisfy the demand of coal transportation, air intake and other engineering function. In spite of the fact that there are 2~3 groups of joints distinctively shown if the roof, the roof is, however stable under the bined action of roof bolts and steel bens. The upper sidewall coal fails and falls in some places, but the depth is limited within . Based on the facts in field, in brief, the support scheme is rational and effective. Good economic and rechnical benefit were obtained. 5. Conclusion The failure pattern of gateway in inclined seam is remarkably anisotropic. The failure zone is not only related to the mechanical properties of strata, but also closely to the stability of sidewall coal body. The sidewall coal failure causes the abutment points to transfer into deep solid coal, increase the free span of the roof and therefore worsen the roof integrity. It is, thus a key task to keep the gateway sidewall sound in gateway maintenance. By gateway loosed zone testing, bined with the inclined bined beam model, bolt parameters can be readily determined. Discrete element method can be adopted to verify the rationality and make some amendment . As for the roof with multiple soft and loose layers, ensuring bolt pretension and installing roof bolts as early as possible are the keys to make the roof stable. Meanwhile, to keep roof integrity with steel bends (sometimes metal is needed) is another important measure. It is proved that bolting can be use in gateway with fragile and weak roof as long as necessary measures are taken, considerable economic benefit can be obtained. References 1. 陶連金 . 大傾角煤層開采礦山壓力顯現(xiàn)及其控制 [學(xué)位論文 ]. 沈陽(yáng):東北大學(xué) . 1996。離散元素法被用于評(píng)估錨桿支護(hù)方案,并且取代了在現(xiàn)場(chǎng)上經(jīng)常采用的監(jiān)測(cè)手段。 巷道 。涉及到地層控制的問題,很少被研究,并且研究地層巷道的學(xué)者就更少了。這些研究在巷道的維護(hù)過程中,起到了積極的作用?;谶@些監(jiān)控結(jié)果,一種螺栓連接的 方法被提出。巷道上緊接著的頂是 2 米厚的沙巖和頁(yè)巖,施加全部的載荷是低的。邊墻的煤卻是又軟又松,很容易掉下來。由于緊鄰頂?shù)牡蛷?qiáng)度,常常會(huì)出現(xiàn)穿透緊鄰頂?shù)拈L(zhǎng)裂縫。 當(dāng)巷道被挖掘好以后,在處應(yīng)力的作用下,上方邊墻的煤層首先破裂,接著下方邊墻的煤層的表面開始屈服變形。 圖 1 離散元素模型的巖石分割 圖 2 巷道周 圍圍巖的狀況 結(jié)果表明兩個(gè)邊墻煤層的失效是不同的,上方的煤層比下方煤層更容易破裂。這樣保證整個(gè)傾斜煤層巷道的穩(wěn)定性的關(guān)鍵就是保證邊墻的堅(jiān)實(shí)和完整。巷道被兩個(gè)到頂?shù)? 米的錨噴支護(hù)支撐,錨噴支護(hù)內(nèi)有一點(diǎn)混凝土預(yù)應(yīng)力。 因此傾斜煤層的巷道很難維護(hù),而且維護(hù)費(fèi)用非常高。一種典型的傾斜組合橫梁模型如圖4 所示。除了以上提到的條件,組合橫梁的安全性一定要被檢查,以保證它的縱向的穩(wěn)定性。 4 巷道的錨桿支護(hù)及其評(píng)定 離散元素法的支撐評(píng)定 我們考慮到兩種情形來比較, 一種是只有頂被錨桿支護(hù);另一種是頂和邊墻都被支護(hù)。 在第二種情形,邊墻煤層的變形和失效被邊墻的錨桿嚴(yán)格控制,邊墻是穩(wěn)定的。因此采用一種全面的包括邊墻錨桿支護(hù)形式是非常重要的。對(duì)于已經(jīng)形成的裂縫,鋼結(jié) 構(gòu)同錨桿頂板一起使用,來保證支撐應(yīng)力和預(yù)防局部頂板掉落。 對(duì)于前面的鄰接壓力所影響的區(qū)域,增加了加固支護(hù)。 更多的關(guān)注應(yīng)該投向巷道的挖掘過程。 巷道的最終測(cè)試 為了評(píng)定支護(hù)方案的效果,在巷道的推進(jìn)和工作面的撤退過程中,巷道就被監(jiān)測(cè)起來。巷道的這些變化是因?yàn)楣ぷ髅娴膭?dòng)力作用。上方邊墻煤層失效而且掉落在某些地方,但深度控制在 米。失效的區(qū)域不只是與地層的機(jī)械性質(zhì)有關(guān),而且與邊墻煤層的穩(wěn)定性有密切關(guān)系。離散元素法可以被采用來檢驗(yàn)合理性,并做一些改善。 英文 參考文獻(xiàn) 1 陶連金 . 大傾角煤層開采礦山壓力顯現(xiàn)及其控制: [學(xué)位論文 ] 沈陽(yáng):東北大學(xué) ~ 79 2 侯朝炯,郭宏亮 . 我國(guó)煤巷錨桿技術(shù)的發(fā)展方向:煤炭學(xué)報(bào) (2):113~ 118 3 陳炎光主編 中國(guó)煤礦巷道圍巖控制 徐州:中國(guó)礦業(yè)大學(xué)出版社 ~ 25 4 陶連金 . 寶山煤礦巷道圍巖松動(dòng)范圍測(cè)試建井技術(shù) .1993(34):67~ 70 5 劉明遠(yuǎn),陶連金,李芳成等 錨桿預(yù)緊 力標(biāo)示圈 . 1993,國(guó)家專利號(hào): 6 張倬元,王士天 . 工程動(dòng)力地質(zhì)學(xué) . 北京: 中國(guó)工業(yè)出版社 , 1964 7 張倬元 . 工程地質(zhì)分析原理 . 北京:地質(zhì)出版社 , 8 張卓元 . 工程地質(zhì)勘探 . 北京:地質(zhì)出版社 , 1981 。同時(shí)用鋼結(jié)構(gòu)(有時(shí)金屬網(wǎng)也需要)來使頂板完整是另一種重要的措 施。因此在巷道的維護(hù)中關(guān)鍵是要保證巷道邊墻的穩(wěn)定性。在經(jīng)濟(jì)和技術(shù)方面獲得很好的益處。然而從整個(gè)圍巖的底層來看,巷道是處在穩(wěn)定的條件下,并且可以滿足煤炭安全運(yùn)輸、通風(fēng)口和其他工程功能的要求。隨著工作面的推進(jìn),巷道開始受到工作面變應(yīng)力的影響。最多延遲時(shí)間不要超過 6 個(gè)小時(shí),否則將會(huì)使頂板變形嚴(yán)重且完整性降低。加固的距離是在工作面前方 25 米。 邊墻的煤層被間距是 米的木料錨桿加固,木料錨桿對(duì)于上方邊墻是 米長(zhǎng),下方邊墻是 米