工程地质学报2024，Vol.32Issue(3)：760-771,12.DOI:10.13544/j.cnki.jeg.2024-0087
不同吸力下伊犁河谷原状非饱和黄土强度特性试验研究
STUDY ON THE STRENGTH CHARACTER TEST OF UNDISTURBED UN-SATURATED LOESS IN ILI BASIN UNDER DIFFERENT MATRIC SUCTIONS
摘要
Abstract
Loess is widely distributed in the Ili Basin,affected by the westerlies,and loess landslides are highly developed.Studying the shear strength and deformation characteristics of unsaturated loess in the Ili Basin under different matric suctions is of great significance.In this paper,undisturbed loess from the Ili Basin in Xinjiang was taken as the study object,and mineral formation analysis and physical property tests were conducted.The consoli-dated undrained shear test with controlled net confining pressure and constant matric suctions was carried out on the loess samples from the Ili Basin using the Model TFB-1 unsaturated soil stress-strain controlled triaxial test appara-tus.The results show that:(1)In the range of matric suction measured by the test,the higher the net confining pressure,the more obvious the hardening characteristics of the stress-strain curve of the sample,and the sample ba-sically shows bulging deformation during the shear process.Under conditions of high matric suction,the stress-strain curves tend to exhibit a softened mode,and the samples are prone to shear failure.(2)The sample's volumetric strain is affected by net confining pressure and matric suction.With an increase in net confining pressure,the volu-metric strain tends to shrink.Under conditions of higher matric suction,the peak dilatancy of the volumetric strain is larger,indicating stronger dilatancy characteristics.(3)Matric suction affects the shear strength parameters of un-saturated loess.The cohesion of the two kinds of samples showed a good linear growth trend with the increase in ma-tric suction.The effect of matric suction on the internal friction angle is relatively low.With the increase in matric suction,the growth rate of the internal friction angle of silty clay samples decreases and tends to 0,while the inter-nal friction angle of silty samples shows no evident change.The experimental results of this study can provide me-chanical parameters and theoretical support for the study of the formation mechanism of loess landslides in the Ili Basin.关键词
非饱和土/基质吸力/抗剪强度/变形特征/伊犁河谷Key words
Unsaturated soil/Matric suctions/Shear strength/Deformation character/Ili Basin引用本文复制引用
伊学涛,尚彦军,孟庆森,孟和,崔振东,贺强..不同吸力下伊犁河谷原状非饱和黄土强度特性试验研究[J].工程地质学报,2024,32(3):760-771,12.基金项目
第二次青藏高原综合科学考察研究项目(资助号:2019QZKK0904),第三次新疆综合科学考察项目(资助号:2022xjkk1305).This research is supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0904)and the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk1305). （资助号:2019QZKK0904）
