外文翻譯--煤巷中相似模擬錨桿支護(hù)的構(gòu)造應(yīng)力場(chǎng)-全文預(yù)覽
【正文】 nt， the surface displacement of the roadway bees rapidly deformed， especially after the shear destruction of the roof and floor and the surface displacement rapidly increases． When the side pressure coefficient λ2． 0， the roof gradually falls， being an arch， the measuring point of the roadway top is destroyed and surface displacement is hard to measure． Functional mechanism of bolt support in coal roadway From the macro deformation of the bolts in the experiment， we conclude that the deformation of the side bolts is mainly caused by tension and the deformation of the roof bolts mainly by shear． Fig 5 shows that the side bolts are deformed because of tension， where the load on the upper shoulder bolt is largest and on the lower bolt smallest． With an increase in the side pressure coefficient， the tension in the bolts gradually increases． When the side pressure coefficient λ2． 0， the load on the bolts changes little． The roof bolts are deformed mainly because of shear． The length of the extension of the lead wire is small， so that the change in resistance of the bolts is also small． Under the effect of tectonic stress， the roof and floor strata are likely to bee shear failure areas． There is a loose swell caused by dislocation， causing deformation in the surrounding rock． The function of the bolts is to constrain the strata from swelling along the axis and to prevent shear perpendicular to the axis． Therefore， the bolts must have properties of high strength， high stiffness and a high shear force， so that it can restrain deformation of the rock． Fig． 5 Changes in electrical signals in bolts This analysis shows that side bolts largely control the sides of the roadway in order to prevent deformation into the roadway space and that roof bolts mainly control shear failure of the roadway． When the rocks are destroyed， the bolts provide the binding force and increase the residual strength of the rocks． In the design of bolt support， we should select bolts with strong tensile ability and high elongation as side bolts， in order to release some deformation energy and which are adaptable to large deformations of the coalin side walls． Bolts with high antishear ability and high stiffness should be selected for roof bolts， to prevent separation， dislocation and shear failure of roof strata． 5 Conclusions From our similarity simulation of bolt support for a coal roadway in a tectonic stress field， we conclude the following． 1)With an increase in tectonic stress， the destruction of the roadway rock accelerates， there is dislocation between the strata in the roof and floor of the roadway and separation between strata gradually increases， 1eading to strata weakness because of shear and a loss of bending ability。 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。當(dāng)側(cè)壓力系數(shù)增加時(shí)，巷道的地表位移迅速增加。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。 2） 邊幫錨桿變形，主要是由張應(yīng)力引起。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。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。導(dǎo)線延長(zhǎng)的長(zhǎng)度小，錨桿的電阻變化也很小。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。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。頂板逐漸陷入一個(gè)拱形；煤巷邊幫顯示整體向巷道空間的趨勢(shì)。當(dāng)λ = ，頂板脫落到巷道內(nèi)，成為曲線向上的拱形。實(shí)驗(yàn)結(jié)果表明，當(dāng)側(cè)壓系數(shù)λ = ，進(jìn)入巷道巖石拉伸，在頂板和底板的地層之間有一個(gè)斷層，但巖石保持完整。位移計(jì)被放置在巷道表面，巖內(nèi)提前埋錨桿。原巖的容重 pγ 是 2． 50 3/cmg ，容重相似性常數(shù) γα 是 ，強(qiáng)度相似常數(shù) tσα =lα γα =33． 4。 3）、在穩(wěn)定的條件下，受高壓控制的液壓系統(tǒng)，可 以裝載很長(zhǎng)一段時(shí)間的模型。平面應(yīng)變模型
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