重塑膨胀土制样长度对试样密度分布的影响  

Influence of Sample Length to the Density Distribution of Remolded Expansive Soil

作　　者：朱洵 张晨[1] 黄英豪[1] ZHU Xun;ZHANG Chen;HUANG Yinghao(Department of Geotechnical Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院岩土工程研究所

出　　处：《人民黄河》2019年第6期128-131,共4页Yellow River

基　　金：国家重点研发计划项目(2017YFC0405106);水利部技术示范项目(SF-201704);中央级公益性科研院所基本科研业务费专项(Y318001,Y318009);国家自然科学基金资助项目(51879166)

摘　　要：在对重塑膨胀土裂隙性问题的单元试验研究中,传统的分层制样法易产生"层间薄弱带",从而影响试验结果的准确性。针对这一问题,采用增加制样高度的单层压实制样方法,探讨了制样高度对重塑膨胀土试样密度的影响。试验结果表明:试样密度沿深度方向变化规律类似,均呈现出顶部大、底部小的分布特征;增加制样高度导致试样顶部与底部密度差及密度变化率发生改变;试样密度变化率随深度分布存在拐点,拐点以上部分密度变化率较小,以下部分较大;随着制样高度的增大,拐点位置向试样下部移动;以拐点位置为基础,初步给出了适合本制样方法的制样高度。In the unit test research of remolded expansive soil fissure problem,the traditional layering sampling method is prone to produce"inter-layer weak zone",which affects the accuracy of the test results.In order to solve this issue,the influence of sample height on the density change of the remolded expansive soil sample was discussed by using a single layer compacting method with increasing sample height.The experimental results show that the density of the specimen is similar in the direction of depth,the distribution of the density of the specimen is large and the bottom is small.The increase of the sample height leads to a change in the density difference between the top and the bottom of the sample and the density change rate.There is a"density turning point"in the density variation rate of the specimen with the depth distribution,and the partial density change rate above the"turning point"is slower and the following part is faster.As the height of the sample is increased,the position of the"density turning point"moves to the lower part of the sample.Based on the"density turning point"position,a sample preparation height suitable for the sample preparation method is preliminarily presented.

关 键 词：重塑膨胀土裂隙 单元试验 制样方法 层间薄弱带 密度拐点 

分 类 号：TV41[水利工程—水工结构工程]