【摘要】：隨著西部大開(kāi)發(fā)戰(zhàn)略的深入開(kāi)展，作為交通線路中的常見(jiàn)結(jié)構(gòu)物，隧道在西部地區(qū)越修越多。由于西部屬于多山且復(fù)雜地質(zhì)地區(qū)，因此，這些隧道都不同程度的受到各種地質(zhì)災(zāi)害的影響，其中高巖溫便是較為突出的一種地質(zhì)災(zāi)害。地溫較高不僅影響隧道的建設(shè)和運(yùn)行，而且對(duì)隧道襯砌結(jié)構(gòu)的安全性產(chǎn)生不利影響。 本文以高海拔、高巖溫地區(qū)隧道—吉沃希嘎隧道工程為依托，通過(guò)現(xiàn)場(chǎng)實(shí)測(cè)、結(jié)合傳熱學(xué)理論基礎(chǔ)，采用ANSYS有限元軟件進(jìn)行數(shù)值模擬計(jì)算，研究了高海拔、高巖溫地區(qū)隧道所在山體初始溫度場(chǎng)分布規(guī)律，并以此為初始條件，對(duì)二次襯砌在溫度場(chǎng)和應(yīng)力場(chǎng)耦合作用下的應(yīng)力分布進(jìn)行了較為細(xì)致的研究。最后，通過(guò)在初支和二次襯砌之間設(shè)置隔熱層，研究了隔熱層對(duì)二次襯砌溫度場(chǎng)分布的影響。論文主要工作及成果如下： （1）運(yùn)用ANSYS有限元軟件數(shù)值模擬了隧址區(qū)初始地溫場(chǎng)分布規(guī)律，得知地表以下25m左右為恒溫層，恒溫層溫度約為26℃，恒溫層至地表之間為變溫層，變溫層溫度受外界影響較大，恒溫層往下為增溫層。 （2）比較隧道開(kāi)挖初始實(shí)測(cè)的巖溫與數(shù)值模擬計(jì)算出的巖溫，發(fā)現(xiàn)兩者最大溫度差僅為4.6℃，兩者數(shù)據(jù)基本吻合，從而檢驗(yàn)了數(shù)值模擬的精確性與可靠性。 （3）以隧址區(qū)初始地溫場(chǎng)為初始條件，模擬了隧道二次襯砌在溫度場(chǎng)和應(yīng)力場(chǎng)耦合下的應(yīng)力分布情況。就斷面二而言，結(jié)果顯示，僅有重力載荷作用時(shí)，仰拱承受的拉應(yīng)力為2.09MPa，最大壓應(yīng)力分布在拱腳處，為12.3MPa；當(dāng)同時(shí)施加重力和溫度載荷后，仰拱承受的拉應(yīng)力增大到2.14MPa，變化較大，最大壓應(yīng)力仍分布在拱腳處，為8.66MPa。 （4）對(duì)于斷面二，同時(shí)施加溫度載荷及重力后，仰拱承受的拉應(yīng)力隨時(shí)間的推移逐漸減小；拱腳處的壓應(yīng)力持續(xù)增大，但變化幅度很小，由加載一個(gè)月后的8.42MPa增大到加載五年后的8.66MPa。 （5）由ANSYS有限元軟件數(shù)值模擬計(jì)算結(jié)果可知，無(wú)隔熱層時(shí)，襯砌施作五天后的最大溫度為45.976℃，分布在襯砌外邊緣，最小溫度分布在仰拱處，為28.342℃。在初支和二次襯砌之間設(shè)置了10cm厚的隔熱層，加載五天后，襯砌的最大溫度為30.226℃，同樣分布在襯砌外邊緣，最小溫度為28.024℃，，分布在仰拱處。由此可見(jiàn)，隔熱材料在很大程度上抑制圍巖的高溫向隧道內(nèi)傳遞。
[Abstract]:With the development of the western development strategy, as a common structure in the traffic lines, more and more tunnels are being built in the western region. Due to the mountainous and complex geological area in the west, these tunnels are affected by various geological hazards to varying degrees, among which the high rock temperature is a more prominent geological hazard. The high ground temperature not only affects the construction and operation of the tunnel, but also adversely affects the safety of the tunnel lining structure. In this paper, based on the tunnel engineering in high altitude and high Yanwen area, the high altitude is studied by using the ANSYS finite element software, based on the field measurement and the theory of heat transfer. The distribution law of initial temperature field of the mountain in which the tunnel is located is studied in detail under the coupling of temperature field and stress field. Finally, the influence of thermal insulation layer on the temperature field distribution of secondary lining is studied by setting insulation layer between primary and secondary lining. The main work and results are as follows: (1) the distribution of initial ground temperature field in tunnel area is numerically simulated by using ANSYS finite element software. It is known that there is a constant temperature layer about 25 m below the ground surface and a constant temperature layer temperature of about 26 鈩

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