【正文】
1 2 3 表 2 顯示,受到越來越多的構(gòu)造應(yīng)力,巷道頂板位移收斂到最大。煤巷道的邊幫和沿彼此在頂板和底板地層滑動(dòng),從側(cè)面墻壁的煤炭進(jìn)入巷道空間和在煤的墻壁成為明顯的塑料脹。側(cè)壓力系數(shù)增加,巷道表面位移變得迅速,尤其是變形后的頂板和底板的剪切破壞,地表位移也迅速增加。當(dāng)側(cè)壓力系數(shù) λ ,頂板逐漸下降,成為一個(gè)拱形,巷道頂部的測量點(diǎn)被破壞,地表位移難以測量。 從 實(shí)驗(yàn)中的錨桿強(qiáng)烈變形,我們得出這樣的結(jié)論:邊幫錨桿變形主要是由張力和變形主要由頂板錨桿剪切破壞引起。圖 5 表明,邊幫錨桿變形由拉伸引起,越靠上的錨桿受力荷載越大,越低的錨桿荷載越小。側(cè)壓力系數(shù)增加,錨桿的張力也逐漸增加。當(dāng)側(cè)壓系數(shù) λ ,錨桿的負(fù)荷變化不大。頂板錨桿主要是由剪切引起的變形。導(dǎo)線延長的長度小,錨桿的電阻變化也很小。頂板和底板的地層在構(gòu)造應(yīng)力作用下,有可能成為剪切破壞區(qū)。那里是一個(gè)松散的錯(cuò)位造成的膨脹,導(dǎo)致圍巖變形。錨桿的功能是限制地層沿軸線膨脹,并防止剪切垂直的軸向破壞。因此,錨桿必須有高強(qiáng) 度,高剛度和高剪切力的屬性,以便它可以抑制變形的巖石。 側(cè)壓力系數(shù) λ 側(cè)壓力系數(shù) λ 圖 5 錨桿上電信號(hào)的變化 這一分析表明端錨桿在很大程度上控制了巷道的邊幫,以防止變形進(jìn)入巷道空間,屋頂螺栓主要控制巷道的剪切破壞。當(dāng)巖石被破壞,錨桿提供約束力和增加巖石的殘余力量。在錨桿支護(hù)的設(shè)計(jì),我們應(yīng)該選擇具有較強(qiáng)的抗拉能力和較強(qiáng)抗剪切能力的錨桿,以釋放一些變形能量,這是適應(yīng)在邊幫煤炭的大變形。頂板錨桿應(yīng)選擇具有較高的抗剪切能力和高強(qiáng)度,以防止分離 、錯(cuò)位和頂板巖層剪切破壞。 5 結(jié)論 從我們的相似模擬在構(gòu)造應(yīng)力場的煤巷錨桿支持,我們得出如下結(jié)論: 1) 構(gòu)造應(yīng)力增加時(shí),巷道圍巖的破壞加速,由于剪切和彎曲能力的損失,使得階層之間形成軟弱結(jié)構(gòu)面,巷道的頂板和底板的錯(cuò)位在各階層之間越發(fā)明顯。最后頂板和底板的階層均形成剪切破壞區(qū),頂板錨桿失去它們的支撐功能并且逐漸脫落。隨著頂板偏移和位移的增加,煤礦從邊幫進(jìn)入巷道,而另一邊幫的完整煤礦依然保持它的完整性。 2) 邊幫錨桿變形,主要是由張應(yīng)力引起。當(dāng)上幫錨桿應(yīng)力較大時(shí),下幫錨桿應(yīng)力相對(duì)較小。當(dāng)側(cè)壓系數(shù)λ 時(shí),錨桿上的 應(yīng)力變化不大,頂板錨桿的負(fù)荷主要是由剪切變形引起的。當(dāng)巖層被破壞,屋頂螺栓提供了約束力,增加巖石的殘余力量。當(dāng)巖層被破壞,頂板錨桿提供了約束力,增加巖石的殘余力量。 3)巷道頂板塌陷是最嚴(yán)重的事件。在頂板和底板地層滑動(dòng)時(shí),邊幫的煤礦順勢進(jìn)入巷道空間。在煤礦邊幫塑膠脹是顯而易見的。當(dāng)側(cè)壓力系數(shù)增加時(shí),巷道的地表位移迅速增加。頂板和底板受剪切破壞后,地表位移大大增加。 致謝 這項(xiàng)工作的資金由國家煤炭資源重點(diǎn)實(shí)驗(yàn)室研究基金提供,和對(duì)中國礦業(yè)大學(xué)煤礦安全深表感謝。 英文原文 : Similarity simulation of bolt support in a coal roadway in a tectonic stress field LU Yan School of Mines,China University of Mining & Technology,Xu zhou,China LIU Chang you State Key Laboratory of Coal Resources and Mine Safety,Xu zhou ,China Abstract: In order to study the mechanism of bolt support and the behavior of strata in a coal roadway under tectonic stress, deformation and destruction of a roof,floor and sides were studied using an experiment in similarity simulation. We also studied the mechanism and types of bolt support functions in the coal roadway. The results show that with an increase in horizontal tectonic stress, the strata in the roof and floor of the roadway gradually separate and bee shear failure areas. Coal in side walIs moves, but its integrity remains intact. Side bolts are mainly affected by tension and roof bolts by the effect of shear. Keywords: tectonic stress; coal roadway; bolt support; similarity simulation 1 Introduction At present bolt support is mainly used in coal roadways. where strata behavior varies under different effects of tectonic stress. Research shows that tectonic stress call be approximately considered as horizontal stress. A considerable amount of research has been carried out on roadways under tectonic stress,both at home and abroad. However,there is little research on bolt support mechanism in the presence of tectonic stress . In our investigation, we used similarity simulation to study the deformation and destruction of roofs, floors and sides, as well as the mechanism and types of bolt support in coal roadways when under horizontal tectonic stress. From our experiment in similarity simulation, we provide a theoretical basis and guidance beneficial to nearby production and insure safe mining practices。 2 Main research content and scheme With similarity simulation, we studied three kinds of strata behavior of a coal roadway in a tectonic stress field。 i)developing conditions for the destruction of the rock surrounding a roadway; ii) the surface displacement of a roof,a floor and side walls ; iii)the mechanism of bolt support and the