發(fā)布時間：2018-03-02 08:29

  本文關(guān)鍵詞： 濕陷性黃土 灰土擠密樁 灰土防滲墻 模型試驗　出處：《蘭州交通大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：從黃土的分布可知,濕陷性黃土在我國占有很大的比例。濕陷性黃土最主要的特性就是其濕陷性,當黃土浸水后強度會急劇降低,伴隨發(fā)生塌陷、下沉等工程災(zāi)害,而這些災(zāi)害會嚴重影響線路或建筑物的正常使用。尤其身處西北,在這個濕陷性黃土廣闊分布的地區(qū),想要進行鐵路或公路的施工,消除或減小黃土的濕陷性變得尤為重要。在工程實際中,對于黃土的濕陷性,最常用的的方法就是防滲處理,因此本文結(jié)合黃土的濕陷性設(shè)計了一種新型的側(cè)向防滲路基結(jié)構(gòu),通過理論分析以及在此基礎(chǔ)的室內(nèi)模型試驗研究了該新型防滲結(jié)構(gòu)在側(cè)向防滲方面的效果,本文的主要工作有:首先,對黃土的基本性質(zhì)做了描述,并講述了黃土的濕陷機理,分析了擠密樁的擠密原理以及防滲機理,為后面的模型試驗提供理論依據(jù)。其次,在機理分析的基礎(chǔ)上進行了室內(nèi)模型試驗,設(shè)計了三組不同的試驗工況,第一組不作處理,第二組和第三組分別采用灰土擠密樁和灰土地下防滲墻處理,并拿后兩組的數(shù)據(jù)與不做處理的第一組工況做對比,試驗得出,經(jīng)過處理的后兩組試驗與第一組對比,水分的滲透速率明顯降慢,防滲性能明顯提高,這是因為擠密樁和防滲墻的處理使得土體密實度變大,滲透系數(shù)變小,加之材料本身也具有一定的隔水效果使得路基的抗?jié)B效果顯著提高。而灰土防滲墻處理的防滲效果較之灰土擠密樁還要更好,這跟灰土擠密樁的樁間距有關(guān)系,試驗中采用的是2.5倍的樁間距,當樁間距不斷縮小,防滲效果也會不斷提升。最后,在分析含水量變化的同時對不同工況下路基的沉降量也做了對比,分析得出第三組處理后的路基沉降量最小,其次是第二組工況,而第一組工況的路基沉降量最大。這是因為防滲效果越好,水分進入路基的量就越小,使的路基發(fā)生濕陷變形的量就越小。
[Abstract]:From the distribution of loess, it can be seen that collapsible loess occupies a large proportion in China. The most important characteristic of collapsible loess is its collapsibility. These disasters can seriously affect the normal use of lines or buildings, especially in the northwest, where collapsible loess is widely distributed, and want to carry out railway or highway construction. It is particularly important to eliminate or reduce the collapsibility of loess. In engineering practice, the most commonly used method for loess collapsibility is anti-seepage treatment, so this paper designs a new lateral anti-seepage subgrade structure combined with loess collapsibility. Through theoretical analysis and laboratory model test, the effects of the new anti-seepage structure on lateral seepage control are studied. The main work of this paper is as follows: firstly, the basic properties of loess are described, and the collapsibility mechanism of loess is described. This paper analyzes the compaction principle and anti-seepage mechanism of compacted pile, which provides the theoretical basis for the model test. Secondly, the indoor model test is carried out on the basis of mechanism analysis, and three groups of different test conditions are designed, the first group does not deal with it. The second group and the third group were treated with lime-soil compaction pile and lime soil underground impervious wall respectively, and the data of the latter two groups were compared with the first working condition without treatment. The results of the experiment showed that the latter two groups were compared with the first group. The permeation rate of water decreased obviously and the impervious performance was improved obviously because the compaction pile and the cutoff wall made the compactness of soil become larger and the permeability coefficient decreased. In addition, the material itself also has a certain water barrier effect to improve the anti-seepage effect of roadbed significantly. But the impervious effect of lime-soil impervious wall is better than that of lime-soil compacted pile, which is related to the pile spacing of lime-soil compaction pile. In the test, the pile spacing is 2.5 times. When the pile spacing is reduced, the anti-seepage effect will be improved. Finally, the settlement of the roadbed under different working conditions is compared with the change of water content. The results show that the subgrade settlement of the third group is the smallest, the second group is the second, and the first group is the largest. This is because the better the anti-seepage effect, the smaller the amount of water entering the roadbed. The smaller the amount of collapsing deformation of the roadbed.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U213.1;U416.1

【參考文獻】

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本文編號：1555766