本文選題：花崗巖　切入點(diǎn)：巖爆　出處：《廣西大學(xué)》2015年碩士論文

【摘要】：巖爆是深埋地下工程巖體在人為開挖或者外界擾動(dòng)的作用下產(chǎn)生的一種工程災(zāi)害,隨著國(guó)內(nèi)深埋水工隧洞及其他地下工程的增多,巖爆災(zāi)害發(fā)生的頻率也日趨升高,巖爆的發(fā)生會(huì)使工程中的圍巖突然向臨空面發(fā)生大面積巖塊彈射、拋擲等破壞現(xiàn)象,這將嚴(yán)重影響工程施工進(jìn)度和威脅施工人員的安全。本文在室內(nèi)花崗巖巖爆試驗(yàn)的基礎(chǔ)上,采用三維離散單元軟件3DEC對(duì)室內(nèi)巖爆試驗(yàn)開展模擬研究�；陔x散元軟件3DEC的功能,對(duì)將進(jìn)行數(shù)值模擬的完整花崗巖試樣離散成大小不一的巖塊單元,巖塊單元之間由接觸面連接,通過選取合適的材料參數(shù)和本構(gòu)模型,結(jié)合軟件隨機(jī)給接觸面賦參數(shù)功能將各接觸面的力學(xué)參數(shù)隨機(jī)化來滿足巖石材料的非均勻性,實(shí)現(xiàn)室內(nèi)花崗巖試樣巖爆彈射破壞過程的三維離散元數(shù)值模擬。結(jié)果表明,模擬結(jié)果與試驗(yàn)結(jié)果基本吻合,表明了本文模擬方法的可行性,克服了以往很多采用基于連續(xù)介質(zhì)的數(shù)值模擬難以模擬巖爆彈射破壞非連續(xù)變形力學(xué)行為的局限性,為研究巖爆破壞機(jī)理提供了一定的幫助。結(jié)合數(shù)值模擬對(duì)物理巖爆試驗(yàn)的模擬,從巖爆破壞過程中巖石內(nèi)部的位移場(chǎng)、應(yīng)力場(chǎng)、能量演化過程三個(gè)方面來開展相關(guān)研究。數(shù)值試驗(yàn)結(jié)果表明,從位移場(chǎng)來分析,巖石在進(jìn)行單面卸載發(fā)生巖爆后,巖石塊體的位移會(huì)向臨空面增大,而未彈射的一些塊體會(huì)發(fā)生微小的位移回彈,同時(shí)在靠近卸載面處的塊體之間會(huì)發(fā)生比較大的剪切位移；從巖石內(nèi)應(yīng)力場(chǎng)來分析,巖石在卸載后,靠近臨空面的巖石在巖爆破壞過程中受到張拉應(yīng)力和剪切作用,表明巖爆發(fā)生過程是在拉剪共同作用的情況下產(chǎn)生的；從能量演化過程來分析,巖石處在未卸載前的真三軸壓縮狀態(tài)時(shí)巖石內(nèi)部一直在聚集彈性應(yīng)變能,且在彈性階段聚集最多,巖石在進(jìn)行單面卸載后,集聚在巖石內(nèi)部的彈性應(yīng)變能開始釋放,釋放的能量大約只有0.84%轉(zhuǎn)換成塊體的動(dòng)能,其中99.16%的能量轉(zhuǎn)換成耗散能,其中耗散能主要用于巖塊單元間裂紋的萌生、擴(kuò)展及貫通。
[Abstract]:Rock burst is a kind of engineering disaster caused by artificial excavation or external disturbance of deep buried underground engineering rock mass. With the increase of deep buried hydraulic tunnel and other underground engineering in China, the frequency of rock burst disaster is also increasing day by day. The occurrence of rock-burst will make the surrounding rock in the engineering suddenly burst into the face of the sky with a large area of rock mass ejected and thrown, which will seriously affect the construction progress of the project and threaten the safety of the constructors. Three dimensional discrete element software (3DEC) was used to simulate the rock burst test in laboratory. Based on the function of discrete element software 3DEC, the intact granite samples were discretized into blocks of different sizes. By selecting appropriate material parameters and constitutive models and combining with the function of randomly assigning parameters to the contact surface, the mechanical parameters of each contact surface are randomized to satisfy the nonuniformity of rock materials. Three-dimensional discrete element numerical simulation of rock burst and ejection failure process of granite samples in laboratory is realized. The results show that the simulation results are in good agreement with the experimental results, which indicates the feasibility of the simulation method in this paper. It overcomes the limitations of many previous numerical simulations based on continuous medium which are difficult to simulate the mechanical behavior of discontinuous deformation of rockburst ejection failure. It provides some help for studying the failure mechanism of rock burst. Combined with numerical simulation to simulate the physical rock burst test, the displacement field and stress field of rock in the process of rock burst failure are analyzed. The results of numerical experiments show that the displacement of rock mass increases to the face of the void after rock burst occurs when the rock is unloaded on one side from the displacement field. However, some blocks without ejection will have a small displacement rebound, and a relatively large shear displacement will occur between blocks near the unloading surface, and from the stress field inside the rock, the rock can be unloaded. The rock near the goaf face is subjected to tensile stress and shear action during the rock burst failure, which indicates that the rock burst occurred under the joint action of tension and shear, and analyzed from the energy evolution process. When the rock is in the true triaxial compression state before unloading, the elastic strain energy has been accumulated in the rock, and the elastic strain energy has been accumulated most in the elastic stage. The elastic strain energy accumulated in the rock begins to release after unloading on one side. Only about 0.84% of the energy released is converted into kinetic energy of the block, of which 99.16% of the energy is converted into dissipative energy. The dissipative energy is mainly used for crack initiation, propagation and penetration between rock blocks.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU45

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前1條

1 侯發(fā)亮;;巖爆的真三軸試驗(yàn)研究[A];第四屆全國(guó)巖石動(dòng)力學(xué)學(xué)術(shù)會(huì)議論文選集[C];1994年

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本文編號(hào)：1657848