【摘要】：節(jié)理巖體的失效破壞往往是由于賦存于其中的原生節(jié)理在荷載作用下產(chǎn)生新生裂紋,并且逐漸擴(kuò)展,使巖橋貫通造成的。錨桿已經(jīng)在巖體邊坡和隧道開挖加固中得到了成功的應(yīng)用,但錨桿錨固段內(nèi)的具體受力分析仍然沒有得到清楚的解決。明確錨固力學(xué)傳遞規(guī)律、建立準(zhǔn)確的界面應(yīng)力理論模型以及采用合理的數(shù)值計(jì)算方法都是進(jìn)行錨桿錨固研究的關(guān)鍵。 利用巖石模擬材料研究了受壓巖石裂紋起裂和擴(kuò)展的力學(xué)機(jī)制,具體通過在長方體石膏試件中設(shè)置中心斜裂紋,觀測到單軸壓縮荷載作用下裂紋的擴(kuò)展過程。試驗(yàn)中觀察到兩種分支裂紋(翼型裂紋和次生裂紋)的產(chǎn)生,并得到了其相應(yīng)擴(kuò)展規(guī)律。同時(shí)利用ABAQUS結(jié)合擴(kuò)展有限元法(XFEM)理論編制單元子程序(UEL),其中假設(shè)巖體的線彈性本構(gòu)關(guān)系和最大主應(yīng)力起裂準(zhǔn)則,模擬了翼型裂紋擴(kuò)展的全過程,其結(jié)果與試驗(yàn)結(jié)果進(jìn)行了對比,重點(diǎn)考察了裂紋傾角、厚度和摩擦系數(shù)對裂紋擴(kuò)展的影響,同時(shí)也考慮了尺寸效應(yīng)的影響。 從錨固段受力連續(xù)性理論出發(fā),采用界面剪應(yīng)力重分布假設(shè),定義出剪切剛度的軟化曲線,并利用ABAQUS軟件自帶的彈簧模型,對典型拉拔試驗(yàn)進(jìn)行了數(shù)值分析,證明了改變砂漿層的尺寸和強(qiáng)度會(huì)對錨桿最大拉拔荷載產(chǎn)生影響。與實(shí)際試驗(yàn)結(jié)果相比,數(shù)值解和實(shí)測值有相當(dāng)?shù)囊恢滦�。借助于三維有限元計(jì)算,嘗試采用ABAQUS中實(shí)體單元與cohesive單元相結(jié)合的形式模擬了在剪切荷載作用下全長注漿錨桿加固節(jié)理巖體中桿體與砂漿、砂漿與巖體的相互作用,并采用接觸定義模擬節(jié)理面之間的作用,進(jìn)一步揭示了錨桿對巖體加固的影響效果。
[Abstract]:The failure and failure of jointed rock mass is usually caused by the original joints occurring in the joints which produce new cracks under the action of load and gradually expand so that the rock bridges are connected. The bolt has been successfully applied in rock slope and tunnel excavation and reinforcement, but the concrete stress analysis in the anchor section has not been solved clearly. The key of anchoring research is to make clear the transfer law of Anchorage mechanics, to establish accurate theoretical model of interface stress and to adopt reasonable numerical calculation method. The mechanical mechanism of crack initiation and propagation in compressed rock is studied by means of rock simulation materials. The crack propagation process under uniaxial compression is observed by setting a central oblique crack in a rectangular gypsum specimen. Two kinds of branch cracks (airfoil crack and secondary crack) were observed and their propagation laws were obtained. At the same time, the element subprogram (UEL), is compiled by means of ABAQUS and (XFEM) theory, in which the linear elastic constitutive relation and the maximum principal stress initiation criterion are assumed to simulate the whole process of crack propagation of airfoil. The results are compared with the experimental results, and the effects of crack inclination, thickness and friction coefficient on crack propagation are mainly investigated, and the effects of size effect are also taken into account. Based on the theory of mechanical continuity of Anchorage section, the softening curve of shear stiffness is defined by using the assumption of redistribution of interfacial shear stress, and the typical pull-out test is numerically analyzed by using the spring model with ABAQUS software. It is proved that changing the size and strength of mortar layer will affect the maximum pull-out load of anchor rod. Compared with the experimental results, the numerical solutions are in good agreement with the measured values. With the aid of three-dimensional finite element calculation, the interaction between bar and mortar, mortar and rock mass in jointed rock mass strengthened by full-length grouting bolt under shear load is simulated by means of the combination of solid element and cohesive element in ABAQUS. The contact definition is used to simulate the action between joints, which further reveals the effect of anchor rod on rock mass reinforcement.
【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】：2013
【分類號(hào)】：TU45

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 高永濤,吳順川,孫金海;預(yù)應(yīng)力錨桿錨固段應(yīng)力分布規(guī)律及應(yīng)用[J];北京科技大學(xué)學(xué)報(bào);2002年04期

2 楊新輝,欒茂田,楊慶,葉祥記,樊成;簡化脆性斷裂裂尖模型及復(fù)合型斷裂判據(jù)[J];大連理工大學(xué)學(xué)報(bào);2005年05期

3 方修君;金峰;;基于ABAQUS平臺(tái)的擴(kuò)展有限元法[J];工程力學(xué);2007年07期

4 趙艷華;陳晉;張華;;T應(yīng)力對Ⅰ-Ⅱ復(fù)合型裂紋擴(kuò)展的影響[J];工程力學(xué);2010年04期

5 雷曉燕;三維錨桿單元理論及其應(yīng)用[J];工程力學(xué);1996年02期

6 朱維申,陳衛(wèi)忠,申晉;雁形裂紋擴(kuò)展的模型試驗(yàn)及斷裂力學(xué)機(jī)制研究[J];固體力學(xué)學(xué)報(bào);1998年04期

7 寇劍鋒;徐緋;郭家平;許秋蓮;;黏聚力模型破壞準(zhǔn)則及其參數(shù)選取[J];機(jī)械強(qiáng)度;2011年05期

8 李錄賢,王鐵軍;擴(kuò)展有限元法(XFEM)及其應(yīng)用[J];力學(xué)進(jìn)展;2005年01期

9 杜效鵠;段云嶺;;準(zhǔn)脆性材料中強(qiáng)不連續(xù)問題的數(shù)值方法若干應(yīng)用及其研究進(jìn)展[J];力學(xué)進(jìn)展;2006年02期

10 方修君;金峰;王進(jìn)廷;;基于擴(kuò)展有限元法的粘聚裂紋模型[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年03期

相關(guān)博士學(xué)位論文 前4條

1 郭少華;巖石類材料壓縮斷裂的實(shí)驗(yàn)與理論研究[D];中南大學(xué);2003年

2 董偉;混凝土Ⅰ-Ⅱ復(fù)合型裂縫起裂準(zhǔn)則的試驗(yàn)研究與裂縫擴(kuò)展過程的數(shù)值模擬[D];大連理工大學(xué);2008年

3 李強(qiáng);壓縮作用下巖體裂紋起裂擴(kuò)展規(guī)律及失穩(wěn)特性的研究[D];大連理工大學(xué);2008年

4 周紹青;工程斷裂中的T應(yīng)力及其對裂紋擴(kuò)展路徑的影響[D];中南大學(xué);2010年

，

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