采用宜昌市广泛分布的风化砂对某一级公路改建项目的膨胀土进行改良。通过改良土室内胀缩性分析,表明采用风化砂改良膨胀土能显著抑制其胀缩特性; 通过室内CBR(加州承载比)试验,得出了掺入风化砂能显著提高原状膨胀土的CBR值,使之达到公路路用标准。探讨了不同的初始干密度、不同掺砂比例对膨胀土CBR值的影响。结果表明:初始干密度和掺砂比例对CBR值有很大的影响,在初始干密度一定时,CBR值随着掺砂比例的增加总体上有所增大; 在掺砂比例一定时,CBR值随着初始干密度的增加而增大。在相同掺砂比例下,CBR值与初始干密度呈幂函数关系。在相同干密度时,当CBR值与掺砂比例在初始干密度较小时,呈线性相关关系; 当初始干密度较大时,呈指数函数关系。
Abstract
The expansive soil of highway reconstruction project was improved by using weathered sand which was widely distributed in Yichang. Through an indoor swell-shrink index test, a conclusion could be drawn that the improved expansive soil could significantly inhibit the swell-shrink characteristics. Through an indoor CBR test, another conclusion could be drawn that expansive soil mixed with weathered sand could obviously improve the CBR value and reach the standard of subgrade filler. The influence of different initial dry density and different sand proportion influence on CBR value of expansive soil were discussed. The results showed that: the initial dry density and the proportion of mixing sand had great influence on CBR value. At a certain initial dry density, the CBR value increased with the increase of sand ratio. At a certain sand proportion, the CBR value increased with the increase of initial dry density. CBR value and initial dry density expressed power relation. When initial dry density was small, CBR value and sand ratio expressed the linear relationship; when initial dry density was high, CBR value and sand ratio expressed the exponential function relationship.
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基金
收稿日期:2013-05-13 修回日期:2013-11-03
基金项目:湖北省教育厅自然科学研究重点项目(D20131304)
第一作者:杨俊,副教授,博士。E-mail: wangjing750301@163.com。
引文格式:杨俊,杨志,张国栋,等. 风化砂改良对膨胀土性能的影响[J]. 南京林业大学学报:自然科学版,2014,38(4):145-148.
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