重塑混合土在三轴摄影试验中的变形特性  

Deformation Characterization of Remodeled Mixed Soils in Triaxial Photographic Test

作　　者：牟春梅[1,2] 阳瑾 李燕霞 张博 MU Chunmei;YANG Jin;LI Yanxia;ZHANG Bo(School of Civil Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学土木工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《河南科技大学学报(自然科学版)》2024年第6期62-68,M0006,M0007,共9页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(41867039);广西自然科学基金项目(2020GXNSFAA297247)。

摘　　要：为研究不同粗细配比的重塑混合土的全过程变形特性,利用摄影测量技术对传统三轴试验进行改良,构建石英砂-红黏土重塑混合土样不同变形阶段的三维模型,得到土样的轴向应变、径向应变以及应力-应变曲线。结果表明:不同粗细配比混合土样的轴向应变、径向应变和偏应力皆随石英砂的质量分数增加而增大。相比传统三轴试验,所得轴向应变偏小,而径向应变偏大。混合土样上部和下部区域的径向变形在轴向位移达8 mm后呈波动性增长,而中部区域的径向变形在轴向位移达4 mm后开始呈现较高的线性增长趋势。粗细配比分别为3∶7、4∶6和5∶5的混合土样,其偏应力会在轴向应变为6%时趋于稳定,粗细配比分别为6∶4、7∶3和8∶2的混合土样,则出现应变软化现象。To investigate the full-process deformation characteristics of remolded mixed soils with different coarse-to-fine ratios,photogrammetry technology was employed to improve the conventional triaxial test.Three-dimensional models of remolded mixed soil samples of quartz sand-red clay at various deformation stages were constructed.The axial strain,radial strain,and stress-strain curves of the samples were obtained.The results reveal that the axial strain,radial strain,and deviatoric stress of mixed soils with different coarse-to-fine ratios increase with the rise in quartz sand mass fraction.Compared to the conventional triaxial tests,smaller axial strains and larger radial strains can be detected.Fluctuating growth in radial deformation is observed in the upper and lower regions of the mixed soil samples after the axial displacement reaches 8 mm.Conversely,a higher linear growth trend is noted in the middle region after the axial displacement reaches 4 mm.Deviatoric stress of remolded mixed soils with coarse-to-fine ratios of 3∶7,4∶6,and 5∶5 are found to stabilize at an axial strain of 6%.In contrast,strain-softening behavior is observed in soils with ratios of 6∶4,7∶3,and 8∶2.

关 键 词：重塑混合土 土样变形 数字图像处理技术 三轴摄影试验 

分 类 号：TU411[建筑科学—岩土工程]