本文選題：緩傾斜多煤巖層 + 上保護(hù)層��； 參考：《中國(guó)礦業(yè)大學(xué)》2017年碩士論文

【摘要】：鉆孔或保護(hù)層采動(dòng)卸壓過程中煤巖體裂隙的產(chǎn)生和演化過程是其損傷的發(fā)展和累積過程,而瓦斯在損傷煤巖體中的流動(dòng)過程是一個(gè)瓦斯運(yùn)移與煤層變形之間相互耦合的復(fù)雜過程。本文根據(jù)巖體力學(xué)、損傷力學(xué)、流體力學(xué)等理論,進(jìn)一步完善考慮損傷的Terzaghi有效應(yīng)力,推導(dǎo)以應(yīng)變?yōu)閮?nèi)變量的損傷演化方程和彈塑性損傷本構(gòu)方程,確立煤體滲透率方程;結(jié)合解吸-滲流-擴(kuò)散力學(xué),建立考慮損傷的滲流-應(yīng)力-損傷的含瓦斯煤巖固氣動(dòng)態(tài)耦合模型,對(duì)實(shí)驗(yàn)區(qū)C13煤層底板巖巷穿層鉆孔抽采瓦斯規(guī)律進(jìn)行研究和理論分析,并與現(xiàn)場(chǎng)工程對(duì)比分析,以驗(yàn)證數(shù)值分析的可行性。綜上所述,本文主要的研究結(jié)論如下:分析謝一礦望峰崗井突出危險(xiǎn)性和瓦斯地質(zhì)規(guī)律等相關(guān)資料,結(jié)合礦區(qū)煤層特征,謝一礦具備優(yōu)越的保護(hù)層開懫條件,同時(shí)進(jìn)行C13煤層的卸壓瓦斯抽采,可以從根本上改變謝一礦瓦斯治理的被動(dòng)局面。采用宏觀和微觀分析相結(jié)合的方法得出淮南煤與瓦斯突出煤層(分層)煤樣具有孔隙結(jié)構(gòu)曲線呈雙“S”形、吸附常數(shù)b0.5MPa-1的孔隙結(jié)構(gòu)特征。通過模型分析:開采保護(hù)層,在采空區(qū)頂(底)板一定范圍的煤巖層內(nèi)形成的卸壓區(qū),在工作面前方和開切眼外側(cè)形成應(yīng)力集中。隨著工作面的繼續(xù)推進(jìn),卸壓保護(hù)范圍增大,卸壓區(qū)底鼓量增大,同時(shí)被保護(hù)煤層工作面前方應(yīng)力集中區(qū)向前移動(dòng)。工作面推進(jìn)超過100m后,被保護(hù)層膨脹帶內(nèi)的最大膨脹率達(dá)到3.2‰,膨脹帶長(zhǎng)期保持并逐漸向回采工作面位置轉(zhuǎn)移,同時(shí),壓實(shí)區(qū)壓縮率也逐漸達(dá)到1.3‰。隨著抽放時(shí)間的持續(xù),抽采瓦斯的影響范圍逐漸擴(kuò)大,鉆孔周圍瓦斯壓力逐漸降低,瓦斯進(jìn)一步解吸,煤層等效應(yīng)力減小,煤層被壓實(shí),其透氣性亦逐漸減弱,鉆孔抽采速率逐漸減小,最終趨于穩(wěn)定。抽采150天后,瓦斯的抽采速率接近27L/min,有效抽采半徑近2m�，F(xiàn)場(chǎng)工程表明:隨著保護(hù)層工作面的向前推進(jìn),測(cè)定卸壓區(qū)C13煤層開始最大相對(duì)膨脹變形為4‰;-780m C13南北底板巖巷穿層鉆孔抽采瓦斯南段,單孔平均流量逐漸增大,最大值為22.0156L/min后逐漸衰減。北段單孔平均流量1.157~2.083 L/min。
[Abstract]:The formation and evolution of fractures in coal and rock mass during the mining and unloading process of borehole or protective layer is the development and accumulation process of its damage. The flow process of gas in damaged coal and rock mass is a complicated process of coupling between gas migration and coal seam deformation. Based on the theories of rock mechanics, damage mechanics and fluid mechanics, the effective stress of Terzaghi considering damage is further improved, and the damage evolution equation and elastic-plastic damage constitutive equation are derived, and the permeability equation of coal body is established. Combined with the mechanics of desorption, percolation and diffusion, the dynamic coupling model of gas-bearing coal and rock with seepage, stress-damage and damage is established, and the law of gas extraction through boreholes in rock roadway of floor of coal seam C13 in experimental area is studied and analyzed theoretically. In order to verify the feasibility of numerical analysis, it is compared with field engineering. To sum up, the main research conclusions of this paper are as follows: analyzing the relevant data, such as outburst risk and gas geological law of Wangfenggang well in Xieyi Mine, combining with the coal seam characteristics of mining area, Xie I Mine has superior conditions for opening protective layer. At the same time, the passive situation of gas control in Xieyi Coal Mine can be fundamentally changed by discharging pressure gas from coal seam C13. By combining macro and micro analysis, it is concluded that the coal samples in Huainan coal and gas outburst coal seam (stratified) have double "S" shape pore structure curve and adsorption constant b0.5MPa-1. Through model analysis: the stress concentration is formed in the pressure relief area formed in a certain range of coal and rock strata of the top (bottom) plate of the goaf and in the front of the face and the outside of the opening hole. As the working face continues to advance, the pressure relief protection range increases, the pressure relief area increases, and the stress concentration area in front of the protected coal face moves forward. The maximum expansion rate of the protected layer in the expansion zone is 3.2 鈥，

本文編號(hào)：2033319