摘要
为研究黄河冲积粉土的工程力学特性,评价粉土路基的稳定性,通过室内试验,分析了粉土作为路基填料的基本物理力学性质,对比研究了不同密实度、含水率下粉土的强度与变形性状。研究表明,黄河冲积粉土的颗粒级配不良,难于压实,压实后空气体积率较大。最优含水率条件下,压实系数为0.90的粉土变形为软化型,随着含水率增加,试样的变形性状逐渐由软化型转变为硬化型,尤其围压高、含水率大时,塑性剪切位移更大;压实系数不超过0.85、含水率不低于最优含水率的试样,变形均为硬化型。压实粉土的黏聚力随压实系数减小或含水率增加显著降低,而内摩擦角的变化不大。压实粉土易产生湿化变形,土体的压实系数对变形量影响显著。
In order to evaluate and treat the distress of silt subgrade by rainfall of Beijing-Jiulong railway in Yellow-River alluvial plain area, the basic physico-mechanical properties of silt were investigated by a series of laboratory experiments, for varying compactnesses and water contents; the deformation and strength behaviors of compacted silt were studied. Results indicate that the silt is poor graded and difficult to be compacted, even at its maximum dry density, compacted silt also has high volume ratio of air. For specimens at optimum water compactness of 90 %, the deformation character is softening. However, with water content increasing, the deformation character of compacted silt changes to hardening, especially for specimens at high confining pressure and at high water content, the plastic shear deformation is more significant. For specimens at compactness lower than 85 % and water content not less than optimum water content, the deformation character is always hardening. Cohesion of compacted silt descends sharply with compactness decreasing or water content increasing; but internal friction angle reduces insignificant. There is remarkable slaking deformation of compacted silt due to wetted; and compactness plays a very important role in slaking deformation.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2008年第2期409-414,共6页
Rock and Soil Mechanics
基金
国家自然科学基金(No.50678020)
铁道部科技研究计划项目(No.2005G012)
北京交通大学科技基金(No.2005SM034)
关键词
粉土
强度
变形
压实系数
含水率
路基
silt
strength
deformation
compactness
water content
subgrade
