摘要
以广西百色某隧道膨胀土围岩为研究对象,开展了不同荷载作用下的有荷膨胀率试验,获得了膨胀潜势定量的计算方法,研究了膨胀率与膨胀潜势随时间、压力的变化规律.研究结果表明:有荷膨胀率随着压力的增大而减少,膨胀潜势则逐渐增大,膨胀率与压力的关系可按幂函数的关系拟合,且相关程度较高;膨胀土的膨胀率与膨胀潜势对压力变化的响应在低应力条件下比高应力条件下更加敏感,稳定后的含水率与膨胀率随压力的变化趋势基本相同;膨胀率的增长率在浸水2 h内随着压力的增大,由逐渐减小变为逐渐增大,2~6 h内基本保持稳定;在试验开始时,同一种膨胀土的膨胀潜势相同,由于上覆压力的因素,改变了土颗粒间的排列方式与水分扩散路径,后期膨胀潜势的差异性逐渐增大;膨胀潜势随时间、压力的变化趋势与膨胀率变化趋势意义相同,膨胀潜势能较好地描述膨胀土膨胀特性发展的过程.
Based on the expansive ratio experiments of expansive soil under different loading conditions,the quantitative computing method of expansive potentiality was obtained for the expansive soil of tunnels in Baise in Guangxi province. The effects of time and compression force under different loadings on expansive ratio and expansive potentiality were investigated. The results indicate that the expansive potentiality is increased with the increasing of compression force,while the expansive ratio is decreased.The relationship between expansive ratio and pressure can be well represented by power function.Compared to low pressure,the expansive ratio and expansive potentiality are more sensitive to pressure change at high pressure. The variation trends of expansive ratio and expansive potentiality are basically the same with the increasing of pressure. After immersed for two hours,the growth rate of expansive ratio decreases with the increasing of pressure,and the variation trend remains stable in the following four hours. At the beginning of tests,the expansive potentialities of the same expansive soil are the same,and their differences are gradually increased with the increasing of time changes of soil particle distributionand moisture diffusion path by pressure force. The swelling characteristics of expansive soil can be well represented by expansive potentiality during the expansion process,and the trend of expansive potentiality with the variating of time and stress has the same significance with that of expansion rate.
出处
《江苏大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第6期713-718,共6页
Journal of Jiangsu University：Natural Science Edition
基金
国家自然科学基金资助项目(51308323)
山东省自然科学基金资助项目(ZR2011DQ008)
水利部堤防安全与病害防治工程技术研究中心开放课题基金资助项目(2014008)
关键词
膨胀土
荷载
膨胀特性
膨胀率
膨胀潜势
expansive soil
loading
swelling characteristics
expansive ratio
expansive potentiality
