本文選題：隱伏溶洞 + 圍巖��； 參考：《成都理工大學》2017年碩士論文

【摘要】：巖溶是西南地區(qū)隧道工程建設中常見的地質災害之一。巖溶地區(qū)修建的隧道工程與隱伏溶洞間的影響關系直接影響隧道的安全性,因此,隱伏溶洞對隧道圍巖的影響是巖溶地區(qū)隧道設計與施工中亟需解決的問題。本文以德寨隧道隱伏溶洞段為研究對象,以FLAC~(3D)數(shù)值模擬試驗為手段,分析總結了德寨隧道單個和多個隱伏溶洞對圍巖穩(wěn)定性影響規(guī)律,并選取典型巖溶斷面進行監(jiān)控量測驗證。論文主要工作內容和結論如下:一、結合德寨隧道的工程條件、已揭露溶洞情況和隧道超前地質預報,對隧址區(qū)的隱伏溶洞進行歸納,按其特征分為以下幾類:與隧道不同距離的隱伏溶洞、距隧道相同距離,相同位置,但高跨比大小不同的隱伏溶洞、位于隧道不同位置的隱伏溶洞、多個隱伏溶洞存在于隧道周圍。二、結合巖石力學理論分析隱伏溶洞對隧道圍巖影響的因素,并根據(jù)德寨隧道隱伏溶洞實際情況,選取不同距離、不同大小、不同高跨比、不同位置為代表因子進行數(shù)值模擬分析。三、利用MIDAS GTS和FLAC~(3D)三維數(shù)值模擬軟件,研究了德寨隧道單個隱伏溶洞和多個組合隱伏溶洞對隧道圍巖的影響,主要得出如下結論:1、以不同距離、大小的隱伏溶洞為單因子變量:隨著溶洞面積增大,隧道拱頂?shù)膞向和z向受力和變形量也相應增加。隨著溶洞與隧道的距離增加,圍巖受力和變形量都相應減小。2、以不同高跨比(即不同長軸和短軸比值)的隱伏溶洞為單因子變量:隧道拱肩存在x向應力集中區(qū),拱肩部位的x向變形量較大,當高跨比從0.5增加到1時,拱肩的x向變形量也隨之增大;當高跨比從1增加到1.5時,拱肩的x向變形量減小,拱肩的z向受力和z向變形量隨著高跨比的增加而變大。3、以不同位置的隱伏溶洞為單因子變量:當溶洞處于隧道邊墻處時,隧道的x、z向應力圖和位移變形圖為不對稱圖形;當溶洞位于隧道拱肩延長線時,隧道拱肩將出現(xiàn)z向受力和z向變形集中區(qū)。4、當隧道拱頂上方與邊墻一側同時存在隱伏溶洞時,拱頂和邊墻部位將產(chǎn)生較大的z向變形,同時存在z向應力集中區(qū)。5、當隧道拱頂上方與底板下方同時存在隱伏溶洞時,拱頂將產(chǎn)生較大的z向變形,同時存在z向應力集中區(qū);底板存在反向z向應力集中區(qū),同時產(chǎn)生向上的z向變形。6、當隧道邊墻一側與底板下方同時存在隱伏溶洞時,邊墻處將產(chǎn)生較大的z向變形,同時存在z向應力集中區(qū),減小了底板的z向變形量和z向應力。7、當隧道拱頂上方、邊墻一側與底板下方同時存在隱伏溶洞時,拱頂和邊墻將產(chǎn)生較大的z向變形,并存在z向應力集中區(qū);減小了底板向上的變形量和z向應力。四、對德寨隧道典型巖溶K21+145斷面進行監(jiān)控量測,驗證了德寨隧道隱伏溶洞對圍巖穩(wěn)定性影響結論的正確性和合理性,說明本文研究成果合理,對巖溶隧道工程具有極高的參考價值。
[Abstract]:Karst is one of the common geological hazards in tunnel construction in southwest China.The influence of the tunnel construction in karst area on the safety of the tunnel directly affects the safety of the tunnel. Therefore, the influence of the hidden karst cave on the surrounding rock of the tunnel is an urgent problem to be solved in the design and construction of the tunnel in karst area.In this paper, taking the hidden karst tunnel section of Dezhai tunnel as the research object, and taking the numerical simulation test of FLACU / 3D as the means, this paper analyzes and sums up the influence law of single or multiple concealed karst caves on the stability of surrounding rock, and selects typical karst sections for monitoring and testing.The main contents and conclusions of this paper are as follows: first, combined with the engineering conditions of Dezhai Tunnel, the situation of the karst cave and the advance geological forecast of the tunnel have been revealed, and the hidden karst cave in the tunnel site has been summarized.According to its characteristics, it can be divided into the following categories: the concealed caverns with different distances from the tunnel, those with the same distance from the tunnel and the same location, but with different height / span ratios, and the concealed caverns located in different locations of the tunnel,Multiple hidden caverns exist around the tunnel.Secondly, according to the theory of rock mechanics, the influence factors of concealed karst cave on the surrounding rock of tunnel are analyzed, and according to the actual situation of hidden karst cave in Dezhai tunnel, different distance, different size and different height / span ratio are selected.The numerical simulation analysis is carried out with the representative factors of different positions.3. Using the software of MIDAS GTS and FLACX 3D, this paper studies the influence of single concealed karst cave and multiple combined concealed karst cave on the surrounding rock of the tunnel. The main conclusions are as follows: 1, at different distances.The size of the concealed cave is a single factor variable: with the increase of the cave area, the x direction and z direction force and deformation of the tunnel dome are increased accordingly.With the increase of the distance between the cave and the tunnel, the stress and deformation of surrounding rock decrease by 0.2. The hidden caverns with different ratio of height to span (that is, different ratio of long axis and short axis) are regarded as single factor variable. The stress concentration zone in the arch shoulder of tunnel exists in x direction.When the ratio of height to span increases from 0.5 to 1, the amount of x direction deformation of arch shoulder increases, and when the ratio of height to span increases from 1 to 1.5, the amount of x direction deformation of arch shoulder decreases.The z direction stress and the z direction deformation of the arch shoulder become larger with the increase of the ratio of height to span, taking the concealed cave in different positions as the single factor variable: when the cave is located at the side wall of the tunnel, the xnz stress diagram and the displacement deformation diagram of the tunnel are asymmetrical;When the cave is located at the extension line of the tunnel arch shoulder, the tunnel arch shoulder will appear Z direction stress and z direction deformation concentration area. When there is a concealed cave above the tunnel arch top and the side of the side wall, the arch roof and the side wall will produce greater z direction deformation.At the same time, there exists Z stress concentration zone. 5. When there are hidden caverns above the tunnel arch top and below the bottom plate, the arch roof will produce larger z direction deformation, and the z direction stress concentration zone will exist, and the bottom plate will have the reverse z direction stress concentration region.At the same time, the upward z direction deformation. 6. When there is a concealed cave at the side of the tunnel wall and under the bottom plate, there will be a larger z direction deformation at the side wall, and there will be a z direction stress concentration area.The z direction deformation and the z direction stress of the bottom plate are reduced. When there is a hidden cave in the side of the side wall and the bottom plate at the top of the tunnel arch, there will be a larger z direction deformation in the arch and the side wall, and there will be a Z direction stress concentration zone.The upward deformation and the z-direction stress of the bottom plate are reduced.Fourthly, the monitoring measurement of typical Karst K21145 section of Dezhai Tunnel verifies the correctness and rationality of the conclusion that the hidden karst cave of Dezhai Tunnel affects the stability of surrounding rock, which indicates that the research results in this paper are reasonable.It has high reference value for karst tunnel engineering.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：U452.11

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