土工合成材料加筋黄土力学性能试验研究

发布时间：2018-01-02 13:08

本文关键词：土工合成材料加筋黄土力学性能试验研究　出处：《武汉理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：黄土在我国分布广泛,面积达64万平方公里,约占全国土地面积的6.6%,主要分布在甘、陕、晋等西北和华北地区。这些地区大量采用黄土修筑公路等土工结构物,其面临的主要问题在于黄土压实困难,路堤填土的抗剪强度低,工后沉降大,容易造成路堤的破坏。掺砂改良可以提高土体的压实性,使得土体的粗颗粒含量增加,改善土体的颗粒级配,在压实过程中加强了粗颗粒的局部接触,使其产生的骨架作用得以增强。在黄土内铺设土工合成材料可以改善土体变形特性,增强土体的承载力。纤维土是加筋土技术的一个重要分支,它是一种土工复合材料,具有一般加筋土所没有的近似各向同性的力学性质以及良好的工程性质。纤维土适宜于解决土木工程中经常出现的变形问题。近年来,聚丙烯纤维以其高强度和与土体良好的结合性而得到广泛的应用。本文通过3种土料(纯黄土,掺砂黄土和掺碎石黄土)、2种加筋材料(土工格栅和聚丙烯短纤维)和2种试验(无侧限抗压和直剪试验),探讨了加筋层数、加筋间距、掺砂(或碎石)量、纤维掺量、含水率和压实度对黄土抗压特性和抗剪特性的影响,得出如下结论：土工格栅加筋黄土的无侧限抗压特性与土样掺砂(或碎石)量、加筋层数以及压实度密切相关。掺砂(或碎石)和加筋均可不同程度的提高黄土的抗压强度,要获得良好的加筋效果,随着掺砂(或碎石)量的增加,需要增加土样的加筋层数。纤维黄土的抗剪强度受纤维掺量、含水率与压实度的影响很大。素黄土和纤维黄土的黏聚力和内摩擦角都因含水率的增大而明显下降。
[Abstract]:Loess is widely distributed in China, covering an area of 640 thousand square kilometers, accounting for about 6.6% of the land area, mainly distributed in Gansu, Shaanxi, Shanxi, northwest and North China. These areas use a large number of highways such as loess soil structure, the main problems facing the Loess compaction is difficult, low shear strength of fill embankment the settlement of embankment, easy to cause damage.
Sand consolidation can improve the compaction of soil, increase the coarse particle content of soil, improve the particle gradation of soil, strengthen the local contact of coarse particles during compaction, and enhance the skeleton function of soil.
The laying of geosynthetics in the loess can improve the deformation characteristics of soil and enhance the bearing capacity of soil.
Fiber soil is an important branch of the reinforced earth technique, it is a kind of geotechnical composite material, which has approximately isotropic mechanical properties of reinforced soil has good engineering properties and deformation problems. Fiber soil suitable for solving civil engineering. In recent years, polypropylene fiber with high the combination of strength and good soil and are widely used.
The 3 kinds of soil materials (pure loess, loess mixed with sand and gravel mixed with loess), 2 kinds of reinforcement materials (geogrid and polypropylene fiber) and 2 (test and unconfined compression test, direct shear) of reinforced layers, reinforcement spacing, sand (or gravel) the amount, fiber content, water content and compaction effect on Loess compressive properties and shear properties, draws the following conclusion:
Unconfined compressive properties and soil sand geogrid reinforced loess (or gravel), the reinforced layers and degree of compaction are closely related. (sand or gravel) and reinforcement can be improved in different degrees of loess compressive strength, to obtain good reinforcement effect, with sand (or the increase in the amount of gravel) need to increase the reinforced layers of soil samples.
Resistance of fiber fiber shear strength of loess, greatly influence the water content and degree of compaction. In Loess and loess Fiber Cohesion and friction angle due to the increasing water content decreased significantly.

【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU444

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