冻融循环作用下粉质砂土的压缩变形特性研究

发布时间：2018-01-12 03:19

本文关键词：冻融循环作用下粉质砂土的压缩变形特性研究　出处：《水利水电技术》2017年11期 　论文类型：期刊论文

【摘要】：以季节冻土区粉质砂土为研究对象,以含水率、压实度与冻融循环次数为控制变量进行了冻融循环试验以及固结压缩试验,并对试验结果与规律进行可行性分析和总结。压缩模量是判断土体压缩性的重要指标,通过室内试验测得粉质砂土的压缩模量,并得出重塑试样的含水率、压实度以及冻融循环次数的相关规律。结果表明:冻融循环3次时压实度为0.85、含水率为16%的试样压缩变形量最大,可达1.118 mm。经过反复冻融10次后试样的压缩变形量趋于稳定。冻融循环15次时,压缩变形率随固结压力的增加而增长。在同一含水率下,压缩变形率随压实度的增加而减小,在同一压实度下,压缩变形率随含水率增加而增大。压缩模量随着含水率的增加而减小,随压实度的增加而增大,随着冻融循环次数的增加而增加。对于粉质砂土,提高压实度、降低含水率是减小路基沉降的有效措施。
[Abstract]:The freezing and thawing cycle test and consolidation compression test were carried out with the control variables of water content compaction degree and freeze-thaw cycle times. The silty sandy soil in seasonal frozen soil region was taken as the research object and the moisture content compaction degree and freeze-thaw cycle times were taken as control variables. The compressive modulus is an important index to judge the compressibility of soil. The compressive modulus of silty sand is measured by laboratory test, and the moisture content of the remolded sample is obtained. The results show that the compaction degree is 0.85 and the moisture content is 16% when the compaction degree is 0.85 and the compression deformation is the largest when the freeze-thaw cycle is 3 times. It can reach 1.118 mm. after 10 times of repeated freezing and thawing, the compression deformation of the sample tends to be stable. When freeze-thaw cycle is 15 times, the compression deformation rate increases with the increase of consolidation pressure. At the same water content, the compression deformation rate increases. The compression deformation rate decreases with the increase of compaction degree, and increases with the increase of moisture content under the same compaction degree, and the compression modulus decreases with the increase of moisture content, and increases with the increase of compaction degree. As the number of freeze-thaw cycles increases, for silty sand, increasing compaction and reducing moisture content are effective measures to reduce subgrade settlement.
【作者单位】：内蒙古科技大学土木工程学院;内蒙古科技大学矿业研究院;
【基金】：国家自然科学基金项目(51464036) 内蒙古自治区自然科学基金博士基金项目(2016BS0509) 内蒙古科技大学创新基金项目(2015QDL07)
【分类号】：U416.1
【正文快照】： 0引言冻土是指零摄氏度以下,并含有冰的各种岩石和土壤。由于冻土中有冰的存在,使得冻土对温度变化极为敏感。冰是构成冻土的必需组分,与土的固体颗粒相反,冰是一种物理化学性质极为特殊的、与其他岩石很不一样的单矿物低温水化岩石,其独特的性质在很大程度上制约着冻土的力学

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