【摘要】：巖體中節(jié)理的存在,導(dǎo)致其宏觀力學(xué)性能大大降低,給支護(hù)工程的設(shè)計提出了很大的挑戰(zhàn)。錨桿錨固技術(shù)由于其安全可靠、經(jīng)濟(jì)實(shí)用的特點(diǎn),備受工程師的青睞。該技術(shù)經(jīng)過一個多世紀(jì)的發(fā)展,但是對錨桿加固的機(jī)理的系統(tǒng)的研究仍然缺乏。拉拔試驗(yàn)是加錨巖體力學(xué)試驗(yàn)中的基本試驗(yàn),可以為今后調(diào)整錨桿的結(jié)構(gòu)參數(shù)、改進(jìn)錨桿的制作工藝提供參考,而剪切試驗(yàn)對于認(rèn)識錨桿對弱面抗剪能力的加固特性,具有重要的意義。因此,本文以全長粘結(jié)式錨桿為研究對象,系統(tǒng)的研究加錨巖體的力學(xué)特性。本次論文采用RFPA系列軟件,既考慮到了細(xì)觀的破壞特點(diǎn),也能模擬宏觀破壞行為,同時考慮了巖體、粘結(jié)材料、錨桿三者之間的相互作用和整體聯(lián)系。分別模擬加錨巖體的拉拔試驗(yàn)和加錨節(jié)理巖體的剪切試驗(yàn),獲取加錨巖體的破壞特征、極限荷載與變形參數(shù),旨在研究不同因素水平對加錨巖體力學(xué)性能的影響,確定錨桿的極限承載能力,揭示錨桿內(nèi)力傳遞規(guī)律與加固機(jī)制。本文首先開展錨桿的拉拔試驗(yàn),與經(jīng)典的Phillips理論進(jìn)行結(jié)合,并與其他學(xué)者的物理實(shí)驗(yàn)進(jìn)行驗(yàn)證對比,驗(yàn)證數(shù)值模型的可行性,然后根據(jù)已有的全長粘接式錨桿的拉拔物理試驗(yàn),設(shè)計了相應(yīng)的數(shù)值正交試驗(yàn),對數(shù)值模擬結(jié)果進(jìn)行整體性的數(shù)理統(tǒng)計分析,并與物理試驗(yàn)結(jié)果進(jìn)行比對,研究了抗拔力與巖石彈模、錨桿埋深的關(guān)系,總結(jié)了錨固巖體的破壞形式和特點(diǎn)。在單根錨桿的拉伸試驗(yàn)基礎(chǔ)上,進(jìn)一步模擬了錨桿間距間的影響和群錨效應(yīng)對破壞效果的影響,系統(tǒng)研究了群錨結(jié)構(gòu)在拉拔和剪切作用下的力學(xué)性能,揭示出其與單錨結(jié)構(gòu)的不同特點(diǎn)。在剪切試驗(yàn)中,本文主要驗(yàn)證加錨節(jié)理巖體抗剪性能的增強(qiáng)機(jī)制,探討加錨注漿節(jié)理面的抗剪性能,揭示錨桿傾角對加錨注漿節(jié)理巖體抗剪性能的影響規(guī)律,總結(jié)錨桿傾角與加錨起伏節(jié)理面抗剪性能的關(guān)系。研究結(jié)果表明：節(jié)理巖體的抗剪強(qiáng)度可以通過錨固的方式得以加強(qiáng)；較小的錨桿傾角具有較大的抗剪能力,而這種提高是犧牲錨桿抗拔能力獲得的,具有一定局限性；當(dāng)起伏角為17°的起伏節(jié)理面時,錨桿傾角α=45°時試樣的抗剪效果最好；為了提高巖體的綜合抗剪能力,可以采用增加節(jié)理單位面積內(nèi)的錨桿數(shù)或者在節(jié)理面注入水泥砂漿的方法。本文的研究結(jié)果,不僅有助于了解加錨巖體的力學(xué)性能,也可以為設(shè)計可靠有效的巖體錨固方案,提供有力的試驗(yàn)數(shù)據(jù)和理論基礎(chǔ)。
[Abstract]:Because of the existence of joints in rock mass, the macroscopic mechanical properties of rock mass are greatly reduced, which poses a great challenge to the design of supporting engineering. Anchorage technology is favored by engineers because of its safe, reliable, economical and practical characteristics. The technology has been developed for more than a century, but the systematic research on the mechanism of anchor reinforcement is still lacking. Drawing test is the basic test in mechanical test of bolted rock mass, which can provide a reference for adjusting the structural parameters of anchor rod and improving the manufacture technology of anchor rod in the future. It is of great significance. Therefore, the mechanical properties of bolted rock mass are systematically studied in this paper. In this paper, RFPA series software is used, which not only takes into account the characteristics of mesoscopic failure, but also simulates the macroscopic failure behavior. At the same time, the interaction and the whole relation among rock mass, bond material and anchor rod are considered. The tensile test of anchored rock mass and shear test of anchored jointed rock mass are simulated respectively to obtain the failure characteristics, ultimate load and deformation parameters of anchored rock mass. The purpose of this paper is to study the influence of different factor levels on mechanical properties of anchored rock mass. Determine the ultimate bearing capacity of anchor, reveal the law of internal force transfer and reinforcement mechanism. In this paper, the drawing test of anchor rod is first carried out, combined with the classical Phillips theory, and compared with the physical experiments of other scholars to verify the feasibility of the numerical model, and then according to the physical test of the full-length adhesive anchor rod, The corresponding numerical orthogonal test is designed, and the numerical simulation results are analyzed and compared with the physical test results. The relationship between the pull-out force and the elastic modulus of rock and the buried depth of the anchor rod is studied. The failure forms and characteristics of anchoring rock mass are summarized. Based on the tensile test of single anchor rod, the influence of the spacing between anchors and the effect of group anchor effect on the failure effect is further simulated, and the mechanical properties of the group anchor structure under the action of drawing and shearing are systematically studied. The difference between the structure and the single anchor structure is revealed. In the shear test, this paper mainly verifies the strengthening mechanism of the shear resistance of the anchored jointed rock mass, discusses the shear behavior of the bolted grouting joint plane, and reveals the influence law of the anchor inclination angle on the shear property of the bolted grouting jointed rock mass. The relationship between Anchorage angle and shear resistance of Anchorage undulating joint is summarized. The results show that the shear strength of jointed rock mass can be strengthened by the way of anchoring, and that the small inclination angle of anchor rod has larger shear resistance ability, and this increase is obtained by sacrificing the pulling ability of anchor rod, and has some limitations, and the results show that the shear strength of jointed rock mass can be strengthened by means of anchoring. When the fluctuation angle is 17 擄, the shear effect of the specimen is the best when the Anchorage angle is 45 擄. In order to improve the comprehensive shear resistance of rock mass, the method of increasing the number of anchors in the joint unit area or injecting cement mortar into the joint surface can be adopted. The results of this paper not only help to understand the mechanical properties of anchored rock mass, but also provide a strong experimental data and theoretical basis for the design of reliable and effective rock mass anchoring scheme.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU45

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相關(guān)期刊論文 前2條

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本文編號：2213809