考虑残积土性能劣化的边坡稳定性研究

发布时间：2018-02-17 07:39

本文关键词： 花岗岩残积土干湿循环强度劣化边坡稳定性　出处：《福建农林大学》2017年硕士论文　论文类型：学位论文

【摘要】：闽东南地区广泛分布着花岗岩残积土,大规模的工程建设导致残积土边坡暴露于自然环境中。天然土体受季节性气候因素影响,长期处于周期性的干湿循环,土体含水率及吸力的反复变化严重影响边坡土体抗剪强度,进而影响边坡稳定性。因此,研究干湿循环效应下残积土性能劣化规律及其对边坡稳定性的影响具有重要的科学意义和现实意义。本文以闽东南地区花岗岩残积土为研究对象,开展室内干湿循环模拟试验,深入探讨不同干湿循环次数花岗岩残积土抗剪强度衰减规律,重点分析不同含水率残积土历经不同次数干湿循环后,土体抗剪强度指标、含水率、干湿循环次数三者之间的内在联系。主要成果如下:(1)土体粘聚力与含水率的对数呈线性负相关,土体内摩擦角与含水率呈线性负相关。随着含水率的增加,土体粘聚力和内摩擦角均呈减小趋势。(2)随着干湿循环次数的增加,土体粘聚力和内摩擦角均呈减小趋势;同一条件下,粘聚力的下降幅度明显大于内摩擦角。随着干湿循环次数的增加,粘聚力减小的程度逐渐降低。(3)土体粘聚力劣化累积量随着干湿循环次数的增加而增加。随着干湿循环次数的增加,粘聚力劣化累积量增加的程度逐渐降低
[Abstract]:Granite residual soil is widely distributed in southeast Fujian, and large-scale engineering construction results in the slope of residual soil being exposed to the natural environment. The natural soil is affected by seasonal climatic factors and is in periodic dry-wet cycle for a long time. The repeated changes of soil moisture content and suction seriously affect the shear strength of the slope soil, and then affect the slope stability. It is of great scientific and practical significance to study the deterioration law of residual soil performance and its influence on slope stability under dry and wet cycling. This paper takes granite residual soil in southeast Fujian as the research object, and carries out indoor dry and wet cycle simulation test. The shear strength attenuation law of granite residual soil with different dry and wet cycles is discussed in depth, and the shear strength index and moisture content of residual soil with different moisture content after different times of dry and wet cycling are analyzed. The main results are as follows: (1) the cohesive force of soil is linearly negatively correlated with logarithm of moisture content, and the angle of internal friction of soil is linearly negatively correlated with water content. The cohesive force and internal friction angle of soil decreased with the increase of dry-wet cycle times, and the cohesion and internal friction angle of soil decreased with the increase of dry-wet cycle times; in the same condition, the cohesive force and the internal friction angle of the soil decreased with the increase of dry-wet cycle times. The decrease of cohesion is obviously greater than that of internal friction angle. With the increase of dry-wet cycle times, The degree of decrease of cohesive force decreased gradually. 3) the cumulative amount of soil cohesion deterioration increased with the increase of dry-wet cycle number, and decreased gradually with the increase of dry-wet cycle number.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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