本文選題：一維凍脹試驗　切入點：等壓凍脹試驗　出處：《北京交通大學(xué)》2014年碩士論文

【摘要】：凍土區(qū)域在我國廣泛分布,凍土病害問題突出,已經(jīng)嚴(yán)重影響到了我國凍土地區(qū)的基礎(chǔ)工程建設(shè)速度和地區(qū)發(fā)展。凍脹融沉是眾多凍害中最為常見的,也較難處理的一種。目前有關(guān)凍土凍脹特性方面的研究不夠成熟,在試驗方法,凍脹機理,凍脹模型等多方面都有待深入和完善。本文針對土體凍脹特性的試驗方法和凍脹機理,凍脹規(guī)律進行研究。 本文的主要研究內(nèi)容包括：1)建立土體凍脹的一維側(cè)限和三維等壓試驗方法；2)開展一維側(cè)限凍脹試驗,通過正交試驗研究土體成分、含鹽量、土體含水量、土體初始干密度、凍融循環(huán)對土體體積變形的影響；3)開展三維等壓凍脹試驗,研究膨潤土的凍脹機理；4)總結(jié)土樣凍脹規(guī)律,建立了土體凍結(jié)過程中體積變化預(yù)測理論模型。 通過研究,本文取得了以下成果和發(fā)現(xiàn)：1)建立了一維側(cè)限凍脹試驗的試驗方法,并針對側(cè)壁約束效應(yīng),提出了體積變形修正公式；2)設(shè)計并加工了溫控體變儀,能夠用于等壓條件下的凍脹曲線測量；3)在凍脹試驗中,發(fā)現(xiàn)粘土在凍結(jié)過程中,隨飽和度增高,土體體變規(guī)律從收縮過度為膨脹。其機理可能在于孔隙水結(jié)晶膠結(jié)引起的收縮變形,和孔隙水結(jié)晶體體積膨脹引起的土體結(jié)構(gòu)膨脹共同作用�；诖藱C理,本文給出了關(guān)于土樣體積變化的簡化預(yù)測模型。
[Abstract]:The frozen soil region is widely distributed in our country, and the problem of frozen soil disease is prominent, which has seriously affected the construction speed and regional development of the foundation engineering in the frozen soil region of our country.Frost heaving and thawing is one of the most common and difficult to deal with.At present, the research on frost heaving characteristics of frozen soil is not mature enough, and many aspects such as test method, frost heave mechanism and frost heave model need to be further improved.In this paper, the test method and mechanism of soil frost heaving are studied.The influence of freezing and thawing cycle on the volume deformation of soil mass. (3) the three-dimensional isobaric frost heave test was carried out, and the frost heave mechanism of bentonite was studied. 4) the frost heave law of soil sample was summarized, and the prediction model of volume change in soil freezing process was established.It can be used to measure the frost heave curve under isobaric condition. In the frost heave test, it is found that in the freezing process of clay, with the increase of saturation, the soil body changes from excessive shrinkage to expansion.The mechanism may lie in the shrinkage and deformation caused by pore water crystalline cementation and the expansion of soil structure caused by volume expansion of pore water crystals.Based on this mechanism, a simplified prediction model of soil sample volume variation is presented.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU442

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相關(guān)期刊論文 前1條

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本文編號：1722150