【摘要】：隨著地下礦開采強(qiáng)度與規(guī)模的擴(kuò)大，為滿足大型開采設(shè)備的使用、運(yùn)輸以及礦井通風(fēng)等要求，巷道尺寸不斷增加。巷道尺寸的增大降低了圍巖的穩(wěn)定性，這給巷道支護(hù)工作帶來新的挑戰(zhàn)。大斷面巷道的支護(hù)已成為一個(gè)亟待解決的難題。 本文以納林河煤礦大斷面巷道支護(hù)問題為背景，通過現(xiàn)場(chǎng)調(diào)研、理論分析、數(shù)值模擬等研究手段，對(duì)大斷面巷道圍巖破壞機(jī)理及其錨網(wǎng)索聯(lián)合支護(hù)技術(shù)進(jìn)行研究，并針對(duì)納林河煤礦的具體地質(zhì)條件和支護(hù)問題提出相應(yīng)支護(hù)對(duì)策。 （1）分析了大斷面巷道變形破壞機(jī)理。大斷面巷道開挖后，巷道圍巖平衡時(shí)的三向應(yīng)力失衡轉(zhuǎn)變?yōu)槎驊?yīng)力，巷道兩幫和頂?shù)装寰霈F(xiàn)應(yīng)力集中現(xiàn)象，造成巷道圍巖強(qiáng)度的降低，最終導(dǎo)致圍巖的變形和破壞。 （2）通過FLAC3D數(shù)值模擬軟件，分析了大斷面巷道尺寸對(duì)巷道穩(wěn)定性的影響。研究結(jié)果表明，巷道斷面積越大，圍巖塑性區(qū)范圍增大，，巷道寬度對(duì)巷道穩(wěn)定性的影響尤其重大，當(dāng)巷道寬度從4m增大到6.5m時(shí)頂板最大位移從65mm增大至85mm，造成巷道支護(hù)難度加大。 （3）分析了錨網(wǎng)索聯(lián)合支護(hù)對(duì)大斷面巷道的作用機(jī)理。巷道支護(hù)后，錨索和錨桿預(yù)緊力的作用可以使圍巖重新恢復(fù)三向應(yīng)力狀態(tài)，有效控制圍巖變形，從而維持巷道圍巖的穩(wěn)定。支護(hù)后錨索可以深入頂板圍巖深處，對(duì)可能發(fā)生松動(dòng)和破裂的巖石起到懸吊作用，由于大斷面巷道跨度比較大，錨索還起到了減跨的作用，降低了頂板的沉降量；兩幫的錨桿可以加固表面破碎煤體，使其同深部穩(wěn)定煤體形成一個(gè)大的錨固體，抑制深部煤體發(fā)生離層，可以有效的控制巷道兩幫的變形。 （4）通過FLAC3D數(shù)值模擬軟件對(duì)錨桿長(zhǎng)度、間排距、夾角、預(yù)緊力大小等對(duì)支護(hù)效果的影響。研究結(jié)果表明，增大錨桿長(zhǎng)度可以使預(yù)緊力有效向圍巖深部擴(kuò)散，壓應(yīng)力主要作用區(qū)為錨桿1/2長(zhǎng)度以內(nèi)；錨桿間排距及夾角的減小可使錨桿之間的作用力相互疊加形成一個(gè)整體的壓縮區(qū)，起到對(duì)圍巖的整體加固作用；增大預(yù)緊力能夠提高錨桿的主動(dòng)支護(hù)效果，隨著錨桿預(yù)應(yīng)力的增大，錨桿群在圍巖中產(chǎn)生的壓應(yīng)力的強(qiáng)度和范圍都有所增加，錨桿預(yù)緊力為50KN時(shí)的最大主應(yīng)力為0.02MPa，預(yù)緊力增大到200KN后最大主應(yīng)力增大至0.09MPa。 （5）針對(duì)納林河煤礦大斷面巷道變形破壞特征及現(xiàn)有支護(hù)方案的不足，提出錨網(wǎng)索聯(lián)合支護(hù)方案并在現(xiàn)場(chǎng)加以應(yīng)用。現(xiàn)場(chǎng)監(jiān)測(cè)結(jié)果表明，該支護(hù)方案有效控制了圍巖變形，支護(hù)效果較為理想。
[Abstract]:With the expansion of underground mining intensity and scale, the size of roadway is increasing in order to meet the requirements of large-scale mining equipment, transportation and mine ventilation. The increase of roadway size reduces the stability of surrounding rock, which brings new challenge to roadway support. The support of large-section roadway has become a difficult problem to be solved. Based on the support problem of large section roadway in Nalinghe coal mine, the failure mechanism of surrounding rock and the combined support technology of anchor, mesh and cable are studied by means of field investigation, theoretical analysis, numerical simulation and so on. According to the concrete geological conditions and supporting problems of Nalinhe coal mine, the corresponding supporting countermeasures are put forward. The main contents are as follows: (1) the deformation and failure mechanism of large section roadway is analyzed. After the excavation of large section roadway, the three direction stress imbalance of roadway surrounding rock balance is changed into two direction stress, and the stress concentration phenomenon appears in both side of roadway and roof and floor, which results in the decrease of surrounding rock strength of roadway, and finally leads to the deformation and destruction of surrounding rock. (2) the influence of roadway size on roadway stability is analyzed by FLAC3D numerical simulation software. The results show that the larger the roadway area is, the larger the plastic zone of surrounding rock is, and the more the influence of roadway width on roadway stability is, when the roadway width increases from 4m to 6.5m, the maximum displacement of roof increases from 65mm to 85mm. The difficulty of roadway support is increased. (3) the action mechanism of bolting, mesh and cable combined support on large section roadway is analyzed. After roadway support, the action of anchor cable and bolt pre-tightening force can restore the three-way stress state of surrounding rock, control the deformation of surrounding rock effectively, and maintain the stability of roadway surrounding rock. After supporting, the anchor cable can go deep into the surrounding rock of the roof and suspend the rock which may be loosened and ruptured. Because of the large span of the roadway with large section, the anchor cable also plays the role of reducing the span and reducing the settlement of the roof. The bolt of the two sides can strengthen the surface broken coal body, make it form a large anchor body with the deep stable coal body, restrain the deep coal body from breaking off, and effectively control the deformation of the two sides of the roadway. (4) the influence of the length of bolt, the distance between rows, the angle of the bolt, the magnitude of pretension force on the support effect by FLAC3D numerical simulation software. The results show that increasing the length of anchor rod can effectively spread the pretightening force to the deep surrounding rock, and the main area of compressive stress is within 1 / 2 of the length of anchor rod. The reduction of the row distance and the angle between the anchors can make the interaction between the anchors superimposed to form a whole compression zone, which can strengthen the surrounding rock as a whole. With the increase of anchor prestress, the strength and range of compressive stress produced by anchor group in surrounding rock are increased, and the maximum principal stress of anchor is 0.02MPa when the pre-tension force of anchor rod is 50KN. The maximum principal stress of 200KN increases to 0.09 MPA. (5) aiming at the characteristics of deformation and failure of large section roadway in Nalinghe coal mine and the deficiency of existing supporting scheme, the combined support scheme of anchor, mesh and cable is put forward and applied in the field. The field monitoring results show that the supporting scheme can effectively control the deformation of surrounding rock and the support effect is ideal.
【學(xué)位授予單位】：內(nèi)蒙古科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TD353

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相關(guān)期刊論文 前2條

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本文編號(hào)：2348785