千枚岩全风化土的抗拉特性研究  

Tensile Characteristics of Fully Weathered Phyllite Soil

作　　者：刘莉 张芹[1] 颜荣涛[1] 赵延平 姜大伟 LIU Li;ZHANG Qin;YAN Rongtao;ZHAO Yanping;JIANG Dawei(Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin University of Technology,Guilin 541004,China;Guilin University of Aerospace Technology,Guilin 541004,China;Guilin Geological Engineering Investigation Institute of China Building Materials Group Limited Company,Guilin 541004,China)

机构地区：[1]桂林理工大学广西建筑新能源与节能重点实验室,广西桂林541004 [2]桂林航天工业学院,广西桂林541004 [3]中国建材集团桂林地质工程勘察院有限公司,广西桂林541004

出　　处：《工业建筑》2022年第12期166-170,共5页Industrial Construction

基　　金：国家自然科学基金项目(11962004);广西自然科学基金项目(2017GXNSFAA198215);广西岩土力学与工程重点实验室项目(桂科岩21-XT-03)。

摘　　要：以千枚岩全风化土为研究对象,采用轴平移法、饱和盐溶液蒸气平衡法测试广吸力范围内不同干密度压实样的土水特征曲线,利用自行研制的单轴拉伸仪测试广饱和度范围内不同干密度压实样的抗拉强度,并结合压汞试验分析抗拉强度变化趋势。试验结果表明:抗拉强度随含水率增加出现两个峰值,认为分别为“液桥”数量增多、胶结力较强与毛细压力增大贡献的结果,这与压汞试验压实样具有“双峰”结构相对应。通过对土样的土水特征曲线的分析,表明干密度较大的压实样饱和含水率较低,进气值较大,抗拉强度越高。表明干密度和含水量对抗拉强度具有不同的影响。验证了已有吸应力概念的抗拉强度模型能够较为合理的预测不同干密度下广饱和度范围千枚岩全风化土的抗拉强度。Taking fully weachered phyllite soil as a reserch object, the pressure plate method and saturated salt solution method were used to test the soil water characteristic curve(SWCC) in a wide suction range of phyllite weathered compaction soils with different dry densities. A uniaxial tensile tester was developed to study the tensile strength of specimens with different dry densities in a wide range of saturation, and combined with the mercury injection test to study tensile strength change trend. The experimental results showed that the tensile strength presented two peaks with increase of the water content, which were considered to be the results of the increased quantity of “liquid Bridges”, capillary pressure and the stronger cementation force respectively. Besides, it was corresponding to the “double peak” structure of the compacted specimens in the mercury injection test. Analyzing the SWCC of soil specimens, it was shown that the higher the dry density of compacted soil specimens was, the lower the saturated water content was;the air entry value was larger, the tensile strength was higher. The results showed that the dry density and water content had different effects on tensile strength. Moreover, it was verified that the model could reasonably predict the tensile strength of fully weathered phyllite soils in the full saturation range with different dry densities.

关 键 词：千枚岩全风化土 抗拉强度 压汞试验 “双峰”结构 

分 类 号：TU41[建筑科学—岩土工程]