石灰改良弱膨胀土击实特性试验研究  

EXPERIMENTAL STUDY ON COMPACTION CHARACTERISTICS OF LIME-TREATED EXPANSIVE SOIL

作　　者：刘瑞[1] 王家鼎[1] 王新忠 

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]中国民航机场建设集团公司西北分公司,西安710075

出　　处：《工程地质学报》2013年第6期864-870,共7页Journal of Engineering Geology

基　　金：国家自然科学基金项目(40972193);高等学校博士学科点专项科研基金(20096101110016;20116101130001)资助

摘　　要：本文以拟建安康机场弱膨胀土为例,用石灰作为改良剂,对这种石灰改良膨胀土开展了一系列击实试验研究。试验样品来自于安康拟建机场跑道区和挖方区的膨胀土,采用CSK-V1型多功能电动击实仪进行重型击实试验。试验结果表明,石灰掺量、含水量、余土高度、焖料时间对干密度有一定的影响,其规律为:石灰掺量越高,最优含水量越大,最大干密度越小;在最优含水量附近,随着石灰掺量的增加,含水量对干密度的影响减小;在击实功、掺灰量、含水量一定时,余土高度越大,干密度越小;最大干密度随着焖料时间以一定的趋势减小,焖料时间48h以后变化不大;同一种石灰掺量时干密度的主要影响因素顺序是:含水量、焖料时间、余土高度。最后,还通过扫描电镜试验,从微观角度对石灰改良土和击实试验结果进行了描述与分析。This paper presents laboratory tests for lime as modifying agent in compaction of expansive soils. The ex- pansive soil samples are from the proposed airport location at An-Kang. The CSK-V1 multi-function electric com- paction instrument is used in laboratory for heavy compaction tests. A series of compaction characteristic tests are conducted. Findings are as follows ： （ 1 ） As lime dosage increases, the maximum dry density decreases, and the op- timum water content increases. （2） In the vicinity of the optimal water content, as lime dosage increases, the effect of water content on dry density decreases. （3） The higher soil height, the smaller dry density in the condition of the same compaction work, lime dosage and water content. （4） Maximum dry density tends to decrease steadily as braised material time increases, which changes little after 48h. （5） The order of main influential factors of dry den- sity is water content, the materials humectation time and the excess soil height with the same kind of lime dosage. Finally, depending on the Scanning Electron Microscope （SEM）, the lime-treated expansive soil and compaction test are described and analyzed from the microscopic point of view.

关 键 词：击实试验 弱膨胀土 焖料时间 石灰改良 高填方 

分 类 号：P642[天文地球—工程地质学]