童国庆,张吾渝,文少杰,苏延桂

• 1:青海大学土木工程学院
• 2:青海省建筑节能材料与工程安全重点实验室

摘要(Abstract)：

为了探究非饱和原状黄土在快速施工条件下,不同含水率、剪切速率和围压对其强度特性的影响,进行了UU三轴剪切试验。试验结果表明:试样的体积含水率在脱湿和吸湿过程中均随着基质吸力的增大而减小。当剪切速率达到1.5 mm/min时,3种含水率试样的黏聚力分别达到各自的峰值43.2 kPa、40.6 kPa和38.7 kPa,当剪切速率小于此值时黏聚力随着剪切速率的增大而增大。剪切速率达到3 mm/min时,黏聚力分别降为31.8 kPa、21.2 kPa和19.6 kPa;在剪切速率仅为0.5 mm/min时,3种含水率下试样的内摩擦角分别为27.5°、27.3°和27.6°。而后,随着剪切速率的增大内摩擦角逐渐减小,降幅分别为1.6°、1.3°、1.8°;试样的黏聚力随着剪切速率的增大表现为先增大后减小,而内摩擦角随着剪切速率的增大逐渐减小。随着含水率的增大,试样的黏聚力明显减小,但含水率对内摩擦角影响甚微。原状黄土的应力-应变曲线、抗剪强度与剪切速率之间是二次函数关系,存在临界剪切速率;与含水率之间呈负相关性,含水率的增大对土体强度具有软化作用;与围压之间呈单向递增函数关系,围压的增大对土体强度具有强化作用。

关键词(KeyWords)： 含水率;剪切速率;土-水特征曲线;应力-应变曲线;抗剪强度指标;破坏强度;影响因素;试验

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金项目(51768060);; 青海省创新服务平台建设专项(2018-ZJ-T01);; 青海省科技计划项目(2017-ZJ-792)

作者(Author): 童国庆,张吾渝,文少杰,苏延桂

DOI: 10.13928/j.cnki.wrahe.2021.01.020

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