【摘要】：隨著國家西部發(fā)展戰(zhàn)略的轉(zhuǎn)移以及經(jīng)濟建設(shè)的需要，寒區(qū)公路隧道修建越來越多。但受多年凍土區(qū)的氣候環(huán)境、地質(zhì)條件、施工技術(shù)的影響，在建或已運行隧道出現(xiàn)了不同程度的凍害。其中主要原因在于寒區(qū)隧道的修建對原巖的熱平衡狀況產(chǎn)生了巨大的改變，洞內(nèi)外溫度環(huán)境造成了隧道融化盤在時空及隧道結(jié)構(gòu)承載力的季節(jié)性變化，使隧道遭受季節(jié)性凍脹作用引起隧道病害。 本文利用數(shù)值模擬計算的方法重點研究了隧道在不同施工及運營階段隧道融化盤的大小改變以及對隧道支護結(jié)構(gòu)力學(xué)性態(tài)的作用。本次研究考慮了伴相變非穩(wěn)態(tài)溫度場、不同階段洞內(nèi)外溫度分布特點、保溫隔熱層的鋪設(shè)、不同圍巖等級等因素，研究總結(jié)了隧道融化盤隨時間的大小變化情況及寒區(qū)隧道支護結(jié)構(gòu)的位移應(yīng)力影響規(guī)律。 根據(jù)隧道實際施工中不同開挖階段及洞內(nèi)外溫度分布的復(fù)雜性，本文采用有限元軟件進行數(shù)值模擬研究主要分為兩部分：一部分是將隧道施工開挖分為毛洞階段、初支階段、二襯及貫通運行階段，考慮材料伴相變非穩(wěn)態(tài)情況下施工暴露時間的長短以及洞內(nèi)外溫度分布的差異進行隧道融化盤大小變化規(guī)律的分析；另外一部分是考慮凍結(jié)巖體與未凍結(jié)巖體的物理材料參數(shù)在冷暖季節(jié)的改變，分別對比分析不同圍巖等級以及不同融化盤范圍深度影響下，，著重分析研究了隧道圍巖襯砌支護結(jié)構(gòu)的受力變形規(guī)律，并進行對比將作用程度進行了粗略量化。 通過對計算結(jié)果的對比分析得出：隧道融化盤季節(jié)變化受洞內(nèi)外溫度環(huán)境影響較大。隧道融化盤隨洞內(nèi)溫度升高范圍不斷增大但增大速率逐漸降低；不同施工階段對隧道融化盤影響不同，其中施工熱源的作用較為明顯；保溫隔熱材料的鋪設(shè)能夠有效避免隧道融化盤的季節(jié)性凍融變化。隨著隧道融化盤深度的變大隧道支護結(jié)構(gòu)的應(yīng)力、位移及塑性應(yīng)變增大，表明隧道融化盤對隧道結(jié)構(gòu)穩(wěn)定具有顯著的作用，仰拱及拱腳位置比較容易先發(fā)生破壞。因此施工中隧道拱腳位置應(yīng)采取一定強度加強措施。
[Abstract]:With the shift of western development strategy and the need of economic construction, more and more highway tunnels are built in cold area. However, due to the influence of climate environment, geological conditions and construction technology in frozen earth regions for many years, different degrees of freezing damage appear in the tunnels under construction or operation. The main reason is that the construction of tunnel in cold region has changed the thermal balance of the original rock greatly, and the temperature environment inside and outside the tunnel has caused the seasonal change of the tunnel melting disk in time and space and the bearing capacity of tunnel structure. The tunnel is damaged by seasonal frost heaving. In this paper, the numerical simulation method is used to study the change of the size of the tunnel melting plate in different construction and operation stages and its effect on the mechanical behavior of the tunnel support structure. This study takes into account the unsteady temperature field with phase change, the temperature distribution characteristics inside and outside the tunnel at different stages, the laying of thermal insulation layer, the different surrounding rock grade, and so on. The variation of the thawing disk with time and the influence of displacement stress on the tunnel support structure in cold region are summarized. According to the complexity of the different excavation stages and the temperature distribution inside and outside the tunnel in the actual construction of the tunnel, this paper uses the finite element software to carry on the numerical simulation research mainly into two parts: one part is to divide the tunnel construction and excavation into the Mao cave stage and the initial branch stage. In the second lining and through operation stage, considering the length of construction exposure time and the difference of temperature distribution inside and outside the tunnel under the condition of material with phase change unsteady state, the variation law of the size of the tunnel melting disk is analyzed. The other part is to consider the change of physical material parameters of frozen rock mass and unfrozen rock mass in the cold and warm seasons. The stress and deformation law of tunnel surrounding rock lining support structure is analyzed and compared, and the action degree is roughly quantified. Through the comparison and analysis of the calculated results, it is concluded that the seasonal variation of the tunnel melting disk is greatly affected by the temperature environment inside and outside the tunnel. With the increasing range of temperature in tunnel, the increasing rate of melting disk decreases gradually, and the influence of different construction stage on tunnel melting disk is different, among which the effect of construction heat source is more obvious. The laying of insulation material can effectively avoid seasonal freeze-thaw change of tunnel thawing disk. The stress, displacement and plastic strain of the tunnel support structure increase with the depth of the melting plate of the tunnel. It shows that the tunnel melting disk has a significant effect on the stability of the tunnel structure, and the inverted arch and arch foot position are easy to be destroyed first. Therefore, some strength strengthening measures should be taken in the position of arch foot of tunnel in construction.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U451

【參考文獻】

相關(guān)期刊論文 前9條

1 黃雙林;昆侖山隧道施工期間圍巖凍融圈的初步研究[J];冰川凍土;2003年S1期

2 劉海京;夏才初;蔡永昌;;存在襯砌背后空洞的隧道計算模型研究及應(yīng)用[J];公路隧道;2007年04期

3 賴遠明,吳紫汪,朱元林,何春雄,朱林楠;寒區(qū)隧道溫度場和滲流場耦合問題的非線性分析[J];中國科學(xué)(D輯:地球科學(xué));1999年S1期

4 趙林,程國棟,李述訓(xùn),趙新民,王紹令;青藏高原五道梁附近多年凍土活動層凍結(jié)和融化過程[J];科學(xué)通報;2000年11期

5 袁捷;王飆;;多年凍土地區(qū)隧道圍巖凍融圈測試技術(shù)[J];青海大學(xué)學(xué)報(自然科學(xué)版);2008年06期

6 呂康成,崔凌秋,解赴東;寒區(qū)隧道春融期滲漏水原因分析及預(yù)防方法[J];現(xiàn)代隧道技術(shù);2001年04期

7 賈曉云;李文江;朱永全;;高原凍巖隧道施工中融化圈深度對圍巖穩(wěn)定性的影響分析[J];巖石力學(xué)與工程學(xué)報;2005年S2期

8 張德華;王夢恕;任少強;;青藏鐵路多年凍土隧道圍巖季節(jié)活動層溫度及響應(yīng)的試驗研究[J];巖石力學(xué)與工程學(xué)報;2007年03期

9 孫鈞，朱合華;軟弱圍巖隧洞施工性態(tài)的力學(xué)模擬與分析[J];巖土力學(xué);1994年04期

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