摘要
为研究击实试验类型对EPS颗粒轻量土击实特性的影响规律,阐明轻量土压缩密实的本质,对3种不同EPS颗粒掺量的轻量土开展标准轻型、标准重型、小型轻型、小型重型4类击实试验,并测量EPS颗粒体积压缩率。结果表明:3种配比轻量土在4类击实试验下,轻量土的干密度随含水率的增加均先增大后减小,曲线形态类似抛物线,所得最优含水率依次接近31%、35%、39%。同配比轻量土,以标准轻型击实试验的最大干密度为标准,其他3类击实试验最大干密度的绝对增长量为-0.014~0.072 g/cm^3,相对增长量为-2.647%~13.611%,4类击实试验所获得的最大干密度基本相同。受击实筒尺寸效应的影响,相同击实功时,小型击实试验的最大干密度大于标准击实试验,但差值较小。相同击实类型时,增加击实功对轻量土最大干密度提高不明显。在击实作用下,EPS颗粒具有明显的塑性压缩,压缩率随含水率和EPS颗粒掺量的增大而减小,其变化范围为0.955%~31.174%。EPS颗粒的塑性压缩和试样孔隙比的减小是轻量土压缩密实的本质,利用小型击实试验代替标准击实试验确定轻量土最优含水率和最大干密度的方法是可行的,可为轻量土工程设计和施工提供参考。
To study the influence of the compaction test types on the compaction characteristics of EPS particles light weight soil,and to reveal the compaction mechanism of light weight soil,three kinds of light weight soil with different EPS particle contents were prepared for four different types of compaction tests,i.e.,standard light-type,standard heavy-type,small light-type and small heavy-type.The volume compression ratios of the EPS particles were measured,respectively.The results show that the dry density of the light weight soil first increases and then decreases with increasing the water content for the three mixed ratios light weight soil under all the compaction tests.The curve shapes are similar to parabola,and the optimum water contents of the three mixed ratios light weight soil are approximately 31%,35%and 39%.For light weight soil having the same ratio,the maximum dry density of the standard light-type compaction test can be taken as the standard.The absolute growth range of the maximum dry density for the other three kinds of compaction tests is from-0.014 g/cm^3 to 0.072 g/cm^3,and the relative growth range is from-2.647%to 13.611%.The maximum dry densities obtained by the four kinds of compaction tests are basically the same.Due to the influence of size effect of the compaction cylinder,the maximum dry density of the small-type compaction test is larger than that of the standard compaction test when the compaction energy is same,but the difference of them is small.For the same compaction test type,it is found that the increase in the compaction energy has no obvious effect on improving the maximum dry density of the light weight soil.Under the compaction action,the EPS particles exhibit obvious plastic compression,and the compression ratio decreases with increasing the water content and the EPS particle content.The volume compression ratio varies in the range of 0.955%to 31.174%.It is feasible to determine the optimum water content and the maximum dry density of the light weight soil by using the small-
作者
杨凯旋
侯天顺
YANG Kai-xuan;HOU Tian-shun(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第6期1971-1982,共12页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51509211)
中国博士后基金(No.2016M602863)
陕西省留学人员科技活动择优资助项目(No.2018031)
陕西省博士后基金(No.2017BSHYDZZ50)
西北农林科技大学外国文教专家项目(No.A213021803)。
关键词
轻量土
击实试验类型
击实特性
最优含水率
最大干密度
EPS
体积压缩率
light weight soil
compaction test types
compaction characteristics
optimum water content
maximum dry density
EPS
volume compression ratio
