發(fā)布時間：2018-05-11 01:15

  本文選題：寒區(qū)隧道 + 凍脹力　； 參考：《西安科技大學(xué)》2017年碩士論文

【摘要】：寒區(qū)隧道工程是交通基礎(chǔ)建設(shè)中的一項特殊工程,寒冷環(huán)境給隧道的設(shè)計和施工造成了新的困難,也帶來了更多的挑戰(zhàn),對隧道建成后的運營和管理也提出了更高的要求。開展寒區(qū)隧道溫度場及凍脹力研究對寒區(qū)隧道的建設(shè)具有重要的意義。本文以蘭新高鐵祁連山隧道為工程依托,對現(xiàn)場監(jiān)測方案、實測監(jiān)測溫度和室內(nèi)試驗等關(guān)鍵數(shù)據(jù)進(jìn)行分析,采取理論研究與有限元數(shù)值模擬計算相結(jié)合的方法進(jìn)行系統(tǒng)研究。首先采集祁連山區(qū)的砂巖試樣,通過熱物性參數(shù)試驗、單軸壓縮試驗、三軸壓縮試驗,對不同含水狀態(tài),不同溫度砂巖試件比熱容及導(dǎo)熱系數(shù)進(jìn)行分析,對不同溫度砂巖單軸抗壓強(qiáng)度、彈性模量、泊松比、不同圍壓時三軸抗壓強(qiáng)度進(jìn)行研究。發(fā)現(xiàn)祁連山地區(qū)砂巖導(dǎo)熱系數(shù)均隨著含水率的增大先增大后減小。砂巖的導(dǎo)熱系數(shù)隨著溫度的降低增大。砂巖體積比熱隨著含水率的增加而減小,室溫狀態(tài)下砂巖體積比熱值最小,隨著溫度的下降,體積比熱容先增大后減小。負(fù)溫情況下溫度越低、圍壓越大砂巖的三軸抗壓強(qiáng)度越大。隨溫度的降低,凍結(jié)巖石的塑性減弱、脆性增強(qiáng)。其次制定隧道溫度監(jiān)測方案,并對現(xiàn)場實測結(jié)果進(jìn)行分析,得到祁連山隧道口外天然地面溫度、隧道環(huán)境溫度以及圍巖溫度的分布特征�？偨Y(jié)出本隧道的環(huán)境溫度與圍巖溫度場的分布規(guī)律。通過對監(jiān)測數(shù)據(jù)的分析,可以為隧道的保溫層設(shè)計提供依據(jù)。再次通過數(shù)值模擬軟件FLAC~(3D)進(jìn)行模擬,對隧道環(huán)境溫度為-10℃、-20℃、-30℃、-40℃,貫通后隧道無保溫層時圍巖溫度場的分布情況展開分析,總結(jié)出圍巖溫度場的分布規(guī)律,模擬計算得到的圍巖溫度沿徑向分布規(guī)律與實際監(jiān)測結(jié)果得到的規(guī)律基本吻合。模擬有保溫層情況下最不利工況圍巖溫度場的分布,通過與無保溫層相同環(huán)境溫度的模擬結(jié)果進(jìn)行對比,為保溫層材料選取提供依據(jù)。最后利用FLAC~(3D)進(jìn)行模擬,研究凍脹力在隧道襯砌不同位置的分布情況以及圍巖等級、凍結(jié)深度、圍巖含水率對凍脹力的影響,計算得到凍脹力沿隧道襯砌分布圖。研究發(fā)現(xiàn)凍脹力沿襯砌輪廓的分布規(guī)律為:仰拱中心凍脹力最小,墻腳凍脹力最大。圍巖級別、含水率、凍脹深度3個影響因素中,含水率對凍脹力的量級及分布影響最大,凍脹深度其次,圍巖級別對凍脹力的影響本質(zhì)為剛性影響。
[Abstract]:Tunnel engineering in cold area is a special project in traffic infrastructure construction. The cold environment brings new difficulties and challenges to the design and construction of the tunnel, and puts forward higher requirements for the operation and management of the tunnel after the completion of the tunnel. It is of great significance to study the temperature field and frost heave force of tunnel in cold region. Based on the Qilian Mountain Tunnel of Lanxin High-speed Railway, this paper analyzes the key data such as field monitoring scheme, measured monitoring temperature and indoor test, and adopts the method of combining theoretical research with finite element numerical simulation to carry out systematic research. Firstly, the sandstone samples from Qilian Mountains are collected, and the specific heat capacity and thermal conductivity of sandstone specimens with different water content and temperature are analyzed by means of thermal physical parameter test, uniaxial compression test and triaxial compression test. The uniaxial compressive strength, elastic modulus, Poisson's ratio and triaxial compressive strength of sandstone at different temperatures were studied. It is found that the thermal conductivity of sandstone in Qilian Mountains increases first and then decreases with the increase of water content. The thermal conductivity of sandstone increases with the decrease of temperature. The volume specific heat of sandstone decreases with the increase of water content, and the specific heat value of sandstone decreases at room temperature, and increases first and then decreases with the decrease of temperature. The lower the temperature is, the greater the confining pressure is, the greater the triaxial compressive strength of sandstone is. With the decrease of temperature, the plasticity of frozen rock weakens and the brittleness increases. Secondly, the tunnel temperature monitoring scheme is established, and the field measured results are analyzed, and the distribution characteristics of natural surface temperature, tunnel ambient temperature and surrounding rock temperature outside the tunnel entrance of Qilian Mountain are obtained. The distribution of ambient temperature and surrounding rock temperature field in this tunnel is summarized. Through the analysis of the monitoring data, it can provide the basis for the design of the insulation layer of the tunnel. The distribution of surrounding rock temperature field is analyzed when the tunnel environment temperature is -10 鈩，

本文編號：1871762