本文選題：高地應力 + 側(cè)壓力系數(shù)　； 參考：《武漢理工大學》2013年博士論文

【摘要】：隨著礦業(yè)工程、水電工程和隧道工程逐步向深部巖體發(fā)展,深部硬脆巖體開挖擾動造成局部應力集中,圍巖所受應力梯度增大,伴隨而來的巖爆災害也逐步增加。而對于不同應力環(huán)境和應力路徑下巖體開挖擾動產(chǎn)生應力梯度對巖爆災害的研究非常少,且目前巖爆試驗還大多處于小尺寸試件的均布加卸載階段,為研究梯度加載對巖體受力直至發(fā)生巖爆的影響,本文通過對在地下工程不同應力環(huán)境與應力路徑下巖體的受力變化進行分析,總結(jié)深部巖體開挖引起圍巖應力場分布的主要形式,采用典型的應力梯度加卸載路徑,結(jié)合自主研發(fā)的巖爆加載裝置對試件進行室內(nèi)試驗研究,以分析不同應力梯度對試件產(chǎn)生巖爆的影響,并通過數(shù)值模擬與室內(nèi)試驗驗證的方法,系統(tǒng)研究了不同應力梯度和應力環(huán)境下的巖爆機理。論文主要取得以下研究成果： (1)通過對隧道開挖影響區(qū)巖體進行應力彈性理論解析解分析,并利用FLAC3D有限差分軟件對不同開挖深度、不同側(cè)壓力系數(shù)下的馬蹄形隧道進行開挖模擬,得到不同開挖深度和側(cè)壓力系數(shù)下,隧道開挖引起巖體應力梯度分布趨勢,總結(jié)隧道開挖掌子面逐漸接近巖體監(jiān)測面并隨開挖進一步推進的過程中,測試面巖體受開挖影響的應力梯度變化規(guī)律,推導出對隧道圍巖所受應力梯度值隨開挖步驟的擬合公式。 (2)選擇滿足巖爆傾向性的相似模型材料,并通過室內(nèi)試驗得到模型試件的基本物理力學指標。利用自主研發(fā)的YB-A型巖爆加載裝置對大尺寸試件進行頂部梯度加載的四組不同加卸載路徑的巖爆試驗,通過改變不同側(cè)壓力系數(shù)、單面卸載時頂部不同加載力大小,對頂部進行不同速率加載的方式,對試件在四種加載路徑下發(fā)生巖爆時,其卸載面的巖爆破壞形態(tài)進行分析,并得出試件產(chǎn)生巖爆時,其頂部所受應力梯度大小與試件經(jīng)歷加卸載環(huán)境和加載路徑的關(guān)系。 (3)為分析試件在四種加卸載路徑下發(fā)生巖爆與試件頂部所受應力梯度分布的影響,通過采集試件在各加載路徑中的應變片變形數(shù)據(jù),對比試件在加卸載前后的CT成像分析,并對巖爆試驗后的巖爆碎屑進行分形分析,得出試件發(fā)生巖爆的過程是試件卸載面附近巖體經(jīng)歷了：試件在受加載時能量吸收-卸載面壓密-試件卸載后在其卸載面中部拉裂破壞-破裂成板的巖爆破壞過程。CT成像圖直觀地反應出試件卸載面附近的加載壓密區(qū)和卸載后試件內(nèi)部的損傷區(qū)；最后通過對巖爆碎屑的分形維數(shù)值計算,建立了巖爆烈度與試件加載路徑的關(guān)系。進一步分析了試件在四種加卸載路徑下的巖爆特性。 (4)基于能量耗散原理,利用3DEC離散元軟件并嵌入彈性能密度的fish語言,計算并追蹤測點的彈性能密度變化的全過程,選擇與室內(nèi)試驗相類似的加載應力梯度對模型試件進行加卸載模擬,以對室內(nèi)試驗結(jié)果進行驗證與補充。模擬結(jié)果再現(xiàn)試件在高應力梯度條件下卸載時,隨著試件頂部應力梯度的逐漸增加,試件卸載面呈局部剝落,乃至出現(xiàn)塊體噴射的巖爆過程,數(shù)值模擬試驗與相同路徑下的室內(nèi)試驗結(jié)果較吻合。
[Abstract]:With the mining engineering, the hydropower project and the tunnel project are gradually developing to the deep rock mass. The local stress concentration is caused by the excavation of the deep hard brittle rock mass, the stress gradient of the surrounding rock increases and the rock burst disaster increases gradually. The stress gradient is produced for rock burst disaster under different stress environment and stress path. In order to study the influence of gradient loading on rock mass to rock burst, this paper analyzes the stress changes of rock mass under the different stress environment and stress path under the underground engineering, and summarizes the surrounding rock should be caused by the deep rock excavation. The main form of the force field distribution is a typical stress gradient loading and unloading path, combined with the self developed rock burst loading device to carry out laboratory tests to analyze the effects of different stress gradient on the rock burst produced by the specimen, and the different stress gradient and stress ring are systematically studied through numerical simulation and laboratory test verification. The main achievements of the paper are as follows:
(1) through the analytical solution analysis of the stress elastic theory of the rock mass in the tunnel excavation, and using the FLAC3D finite difference software to simulate the excavation of the horseshoe tunnel under different excavation depth and different side pressure coefficient, the stress gradient distribution trend of rock mass caused by tunnel excavation under different excavation depth and side pressure coefficient is obtained, and the tunnel is summed up. In the course of the tunnel face gradually approaching the monitoring surface of rock mass and with the process of excavation further, the stress gradient change law of the rock mass affected by the excavation is tested, and the fitting formula of the stress gradient value of the tunnel surrounding rock is derived with the excavation step.
(2) select the similar model materials that meet the tendency of rock burst, and get the basic physical and mechanical indexes of the model specimens through indoor test. By using the independent YB-A type rock burst loading device, four groups of different loading and unloading paths on the top of the large size specimen are tested on the top gradient loading path. By changing the different side pressure coefficient, the single side unloading is changed. At the top of the different loading force, the top is loaded with different speed, and the rock burst failure pattern of the unloading surface is analyzed when rock burst occurs under four loading paths, and the relationship between the stress gradient on the top of the specimen and the loading and unloading environment and loading path is obtained when the specimen is produced by rock burst.
(3) in order to analyze the influence of the rock burst and the stress gradient distribution on the top of the specimen under four loading and unloading paths, the CT imaging analysis of the specimen before and after loading and unloading is compared by collecting the strain data of the strain sheet in each loading path, and the fractal analysis of the rock burst after the rock burst test is carried out, and the rock burst of the specimen is obtained. The process is that the rock mass near the unloading surface of the specimen is experienced: the.CT image of the rock burst failure process at the unloading surface after the loading is loaded by the loading - unloading surface pressure - the rock burst failure process in the middle of the unloading surface after the loading is unloaded. By calculating the fractal dimension of rock burst, the relationship between the rock burst intensity and the loading path of the specimen is established, and the rock burst characteristics of the specimen under the four loading and unloading paths are further analyzed.
(4) based on the principle of energy dissipation, using the 3DEC discrete element software and embedding the fish language of elastic energy density, the whole process of elastic energy density change is calculated and tracked, and the loading stress gradient similar to the laboratory test is used to simulate the loading and unloading of the model test parts, so as to verify and supplement the laboratory test results. With the increasing stress gradient at the top of the specimen under the high stress gradient, the unloading face of the specimen is partial peeling and even the rock burst in the block ejection. The numerical simulation test is in good agreement with the laboratory test results under the same path.
【學位授予單位】：武漢理工大學
【學位級別】：博士
【學位授予年份】：2013
【分類號】：TU45

【參考文獻】

相關(guān)期刊論文 前10條

1 李長洪,蔡美峰,喬蘭,王雙紅;巖石全應力-應變曲線及其與巖爆關(guān)系[J];北京科技大學學報;1999年06期

2 楊小林,王樹仁;巖石爆破損傷斷裂的細觀機理[J];爆炸與沖擊;2000年03期

3 蔡朋;汪安全;汪斌;鄔愛清;;用能量準則分析巖石應力-應變Ⅱ型全過程曲線的合理性[J];長江科學院院報;2010年03期

4 徐林生,王蘭生,李天斌;國內(nèi)外巖爆研究現(xiàn)狀綜述[J];長江科學院院報;1999年04期

5 徐濤,唐春安,張哲,張永彬;單軸壓縮條件下脆性巖石變形破壞的理論、試驗與數(shù)值模擬[J];東北大學學報;2003年01期

6 姜福興;楊淑華;成云海;張興民;毛仲玉;徐方軍;;煤礦沖擊地壓的微地震監(jiān)測研究[J];地球物理學報;2006年05期

7 梁志勇,連凌云,石豫川;巖爆機理的統(tǒng)計損傷解釋[J];地質(zhì)災害與環(huán)境保護;2004年02期

8 周春宏;;某水電站長探洞的巖爆特征[J];地質(zhì)災害與環(huán)境保護;2006年01期

9 謝和平,高峰,周宏偉,左建平;巖石斷裂和破碎的分形研究[J];防災減災工程學報;2003年04期

10 王揮云,李忠華,李成全;基于巖石細觀損傷機制的巖爆機理研究[J];遼寧工程技術(shù)大學學報;2004年02期

相關(guān)博士學位論文 前2條

1 劉立鵬;錦屏二級水電站施工排水洞巖爆問題研究[D];中國地質(zhì)大學（北京）;2011年

2 景鋒;中國大陸淺層地殼地應力場分布規(guī)律及工程擾動特征研究[D];中國科學院研究生院（武漢巖土力學研究所）;2009年

，

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