循环荷载作用下泥炭质土的动变形特性试验研究
发布时间：2019-01-10 09:16
【摘要】：泥炭质土是一种具有明显区域性的特殊土。通过一系列不同围压、固结比、加载频率等条件下的分级加载动三轴试验,研究了昆明泥炭质土在循环荷载作用下的动变形特性。从动骨干曲线、应力-应变滞回曲线和动弹性模量等方面重点分析了围压、固结比、加载频率对泥炭质土变形特性的影响。试验结果表明:泥炭质土的动应变随动应力幅值非线性增长,且存在某一临界动应力,当动应力幅值达到临界动应力值后,应变急剧增长,土体结构发生破坏;围压对泥炭质土动变形的影响最为显著,固结比次之,加载频率最小;固结比对泥炭质土动变形的影响程度依赖于围压,围压越大,固结比的影响越明显;相同循环振级下,泥炭质土的弹性变形随围压和固结比增大而减小,加载频率愈低,土体的弹性变形愈大;随着循环振次的增加和振级水平的提高,泥炭质土刚度逐渐下降,塑性变形产生并累积增长,围压和固结比越大,加载频率越低,泥炭质土的塑性变形越大。
[Abstract]:Peat soil is a special soil with obvious regional features. Based on a series of dynamic triaxial tests under different confining pressure, consolidation ratio and loading frequency, the dynamic deformation characteristics of Kunming peat soil under cyclic loading were studied. The influences of confining pressure, consolidation ratio and loading frequency on the deformation characteristics of peat soil were analyzed in the following key curves, stress-strain hysteretic curves and dynamic elastic modulus. The experimental results show that the dynamic strain of peat soil follows the nonlinear growth of dynamic stress amplitude, and there exists a certain critical dynamic stress. When the amplitude of dynamic stress reaches the critical dynamic stress value, the strain increases sharply and the soil structure is destroyed. The effect of confining pressure on the dynamic deformation of peat soil is the most significant, the consolidation ratio is the second, and the loading frequency is the least, the influence of consolidation ratio on the dynamic deformation of peat soil depends on the confining pressure, the greater the confining pressure is, the more obvious the effect of consolidation ratio is. Under the same cyclic vibration level, the elastic deformation of peat soil decreases with the increase of confining pressure and consolidation ratio, and the lower the loading frequency, the greater the elastic deformation of soil. With the increase of cyclic vibration times and the increase of vibration level, the stiffness of peat soil decreases gradually, the plastic deformation occurs and accumulates, the larger the confining pressure and consolidation ratio, the lower the loading frequency, the greater the plastic deformation of peat soil.
【作者单位】： 中南大学土木工程学院;昆明理工大学建筑工程学院;长沙市轨道交通集团有限公司;
【基金】：国家自然科学基金项目(No.51108461,No.51308270) 国家重点基础研究发展计划项目(973计划)(No.2011CB013802)~~
【分类号】：TU447
本文编号：2406149
[Abstract]:Peat soil is a special soil with obvious regional features. Based on a series of dynamic triaxial tests under different confining pressure, consolidation ratio and loading frequency, the dynamic deformation characteristics of Kunming peat soil under cyclic loading were studied. The influences of confining pressure, consolidation ratio and loading frequency on the deformation characteristics of peat soil were analyzed in the following key curves, stress-strain hysteretic curves and dynamic elastic modulus. The experimental results show that the dynamic strain of peat soil follows the nonlinear growth of dynamic stress amplitude, and there exists a certain critical dynamic stress. When the amplitude of dynamic stress reaches the critical dynamic stress value, the strain increases sharply and the soil structure is destroyed. The effect of confining pressure on the dynamic deformation of peat soil is the most significant, the consolidation ratio is the second, and the loading frequency is the least, the influence of consolidation ratio on the dynamic deformation of peat soil depends on the confining pressure, the greater the confining pressure is, the more obvious the effect of consolidation ratio is. Under the same cyclic vibration level, the elastic deformation of peat soil decreases with the increase of confining pressure and consolidation ratio, and the lower the loading frequency, the greater the elastic deformation of soil. With the increase of cyclic vibration times and the increase of vibration level, the stiffness of peat soil decreases gradually, the plastic deformation occurs and accumulates, the larger the confining pressure and consolidation ratio, the lower the loading frequency, the greater the plastic deformation of peat soil.
【作者单位】： 中南大学土木工程学院;昆明理工大学建筑工程学院;长沙市轨道交通集团有限公司;
【基金】：国家自然科学基金项目(No.51108461,No.51308270) 国家重点基础研究发展计划项目(973计划)(No.2011CB013802)~~
【分类号】：TU447
【相似文献】
相关期刊论文 前2条
1 饶军应;张庆文;;云南省泥炭、泥炭质土地基治理技术进展[J];西部探矿工程;2007年10期
2 王方中;赵朝发;张珏;林锦涛;;西湖泥炭质土微观结构和矿物组成分析[J];公路工程;2013年04期
相关硕士学位论文 前4条
1 高松;有机酸对泥炭质土水泥土的腐蚀性试验研究[D];昆明理工大学;2016年
2 窦兴琦;滇池周边泥炭质土水泥土帷幕截水性能试验研究[D];昆明理工大学;2014年
3 赵朝发;泥炭质土物理力学特性、本构模拟及工程应用[D];浙江大学;2014年
4 熊恩来;云南泥炭、泥炭质土的力学特性及本构模型研究[D];昆明理工大学;2005年
，本文编号：2406149
本文链接：https://www.wllwen.com/jianzhugongchenglunwen/2406149.html
