本文選題：凍結(jié)溫度場 + 導(dǎo)熱系數(shù)��； 參考：《安徽理工大學(xué)》2015年碩士論文

【摘要】：本文首先對人工凍結(jié)法、凍結(jié)溫度場、凍土導(dǎo)熱系數(shù)及其反分析相關(guān)理論基礎(chǔ)知識進(jìn)行了闡述,然后以此為理論工具,以山西梵王寺礦西風(fēng)井凍結(jié)工程(雙圈管差異凍結(jié))為背景,對此礦井凍結(jié)溫度場進(jìn)行了實(shí)測研究,同時對兩個代表性土層(88m砂質(zhì)黏土層和155m粉質(zhì)黏土層)的凍土導(dǎo)熱系數(shù)進(jìn)行了試驗(yàn)和反分析研究,并結(jié)合ANSYS大型軟件及反分析出的等效導(dǎo)熱系數(shù)對凍結(jié)溫度場的分布進(jìn)行了模擬和分析,最后對凍結(jié)壁的發(fā)展?fàn)顩r進(jìn)行預(yù)測并提出一些凍結(jié)建議。 凍結(jié)溫度場實(shí)測研究中設(shè)置了三個測溫孔,分別位于外圈管外側(cè)、兩圈管中間和內(nèi)圈管內(nèi)側(cè),對200天內(nèi)的凍結(jié)溫度場變化情況進(jìn)行了實(shí)測,主要分析了積極凍結(jié)期內(nèi)的土層溫度發(fā)展變化狀況,得出土層實(shí)測溫度80天之前基本全部降到0℃以下,之后降溫速度變緩,180天以后趨于穩(wěn)定；土層實(shí)測溫度場與測溫孔的位置有關(guān),凍結(jié)100天內(nèi)T1、T2、T3平均降溫速度分別為0.21℃/d、0.17℃/d、0.16℃/d；凍結(jié)方式對降溫速度有明顯影響,凍結(jié)孔數(shù)量增大一倍,195m粗砂巖T1、T2孔平均降溫速度約是475m粗砂巖的1.6倍；凍土導(dǎo)熱系數(shù)試驗(yàn)研究中考慮了含水量、干密度、土性及凍結(jié)溫度等影響因素,分別對各種因素與凍土導(dǎo)熱系數(shù)的關(guān)系進(jìn)行了試驗(yàn)分析,得到含水率及干密度因素影響最為顯著,四個含水率下的凍結(jié)粉質(zhì)黏土、砂質(zhì)黏土導(dǎo)熱系數(shù)隨干密度的增長速率分別約是融化狀態(tài)下的4倍和3倍等若干重要結(jié)論；凍土導(dǎo)熱系數(shù)反分析過程中使用了選擇法及最小二乘法的理念,結(jié)合試驗(yàn)值設(shè)置了一組導(dǎo)熱系數(shù)序列,選擇使目標(biāo)函數(shù)最下的導(dǎo)熱系數(shù)值做為最終的等效導(dǎo)熱系數(shù),分別為2.0W/(m·K)、1.9W/(m-K),然后將此導(dǎo)熱系數(shù)值下的溫度場模擬值與實(shí)測值進(jìn)行對比,結(jié)果顯示兩個層位三個測溫孔模擬與實(shí)測差值基本維持在2℃以內(nèi),表明試驗(yàn)和反分析的合理及可靠性；最后本文利用ANSYS軟件對88m層位的溫度場、凍結(jié)壁厚度及平均溫度進(jìn)行模擬預(yù)測,并調(diào)取了溫度場云圖輔助分析,提出要適當(dāng)升高內(nèi)圈管鹽水溫度等意見來保證井筒掘進(jìn)施工的高效性和安全性。 本文采用的是理論、實(shí)測、試驗(yàn)及模擬相結(jié)合的可靠研究方法,本文的研究成果在一定程度上彌補(bǔ)了凍土導(dǎo)熱系數(shù)研究的不足,同時可為凍土導(dǎo)熱系數(shù)反分析提供一條思路,也可為類似地質(zhì)條件下的人工凍結(jié)工程提供一種參考,具有較高的研究價值和重要的工程意義。
[Abstract]:In this paper, the theoretical basis of artificial freezing method, freezing temperature field, thermal conductivity of frozen soil and its back analysis are described, and then used as a theoretical tool. Based on the freezing project of west wind well in Fanwangsi Mine, Shanxi Province, the freezing temperature field of this mine is studied. At the same time, the thermal conductivity of permafrost of two representative layers of sand clay layer (88 m) and silty clay layer (155 m) is studied by experiments and back analysis. The distribution of freezing temperature field is simulated and analyzed by using ANSYS software and equivalent thermal conductivity. Finally, the development of freezing wall is forecasted and some freezing suggestions are put forward. In the study of freezing temperature field, three temperature measuring holes were set up, which were located outside the outer ring tube, in the middle of the two circles tube and inside the inner ring tube. The change of the freezing temperature field in 200 days was measured. This paper mainly analyzes the development and change of soil layer temperature during the active freezing period, and draws the conclusion that the measured temperature of soil layer dropped to 0 鈩，

本文編號：1853882