| 含水量和干密度对压实黄土工程特性的影响研究 |
| Alternative Title | Research of Moisture and Dry Density in Compacted Loess on Engineering Characteristics
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| 刘鹏飞 |
| Thesis Advisor | 吕擎峰
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| 2015-05-23
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| Degree Grantor | 兰州大学
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| Place of Conferral | 兰州
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| Degree Name | 硕士
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| Keyword | 干密度
工程特性
压实黄土
强度
水分
压缩变形系数
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| Abstract | 本文选取兰州市九州台地区黄土试样通过微细观试验、抗压强度试验以及压缩试验进行研究，力求结合宏观强度特性和微细观结构特征，探究含水量和干密度对压实黄土工程特性的影响。经过试验研究表明：
（1）干密度较小的试样，其压缩变形主要为大孔隙的破坏压密；干密度较大试样的压缩变形主要源于中小孔隙的进一步压密。最大干密度的试样具有相对均匀的微观结构。
（2）最优含水量干侧和湿侧具有相同干密度的压实黄土，在不同含水量状态下压缩变形机理是不同的，越靠近最优含水量差异越大。最大干密度压实黄土具有较强的水敏性，其工程特性极易受水分变化的影响。
（3）同一干密度试样，在最优含水量（ω=17%）的干侧时其抗压强度随着含水量的增加而增大，在最优含水量的湿侧则反之；含水量的变化不仅影响了压实黄土试样的抗压强度，同时还影响了其弹性模量和应力路径。 |
| Other Abstract | Compacted loess as the main building materials widely used in earth dam, highway, railway and airport runway and other projects in arid and semiarid region along with many engineering disease problem.There are two aspects due to the disease,on one hand, the quality of the construction or human factors, on the other hand,the engineering properties of compacted loess damaged by the change of the moisture. To explore the moisture and dry density of the compacted loess engineering characteristics, Jiu Zhou-tai loess sample adopted in microcosmic test, strength and compression test, try to combine macroscopic strength and micro structure characteristics in this paper. The tests show that:
(1) The smaller dry density sample,compression deformation owe to the destruction of the macrovoid condense.Larger dry density sample, the compression deformation due to the result of small and medium pore further consolidation.Maximum dry density sample have the trait of relatively homogeneous microstructure. There is great difference in pore size percentage which one similar dry density samples but in different compaction moisture.
(2) The same dry density of compacted loess, which has disparate compression deformation under different moisture states, increasingly obvious with the more close to the optimal moisture. It has strong water sensitivity and the engineering properties susceptible to moisture when the compacted loess in maximum dry density. There is no collapsibility when the sample under the compaction water content,and it will collapse in other water states. All the compacted loess are collapsibility when the moisture more than optimum moisture content.
(3) As the same dry density,the compression strength increased with the moisture when the water lower than the optimum water (17%) , whereas it reduced with the moisture. The moisture not only impact on the compression strength of compacted loess but also effect the modulus of elasticity and stress path.The influence of moisture on compression strength is not obvious at low dry density, and the it will be evident if the dry density increased. |
| URL | 查看原文
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| Language | 中文
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| Document Type | 学位论文
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| Identifier | https://ir.lzu.edu.cn/handle/262010/226383
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| Collection | 土木工程与力学学院
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Recommended Citation
GB/T 7714 |
刘鹏飞. 含水量和干密度对压实黄土工程特性的影响研究[D]. 兰州. 兰州大学,2015.
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