摘要
将数字图像测量技术应用于常规三轴试验中,获得三轴试验过程中样品表面各点的变形信息,用以分析样品剪切变形特征。本文对取自南海神狐海域的海底砂土,开展不同围压、初始相对密实度的固结排水剪切试验。研究南海砂土抗剪强度变化规律,并基于数字图像测量系统着重探讨了南海砂样剪切变形破坏全过程的规律。试验结果表明:南海砂土在不同围压及密实度下均表现出不同程度的应变软化特性。试样的破坏类型均为“单缝破坏型”,剪切带在偏应力达到峰值强度约1/2时开始形成,在峰值强度过后的应变软化阶段完全形成。南海砂土剪切带倾角的实测值为53.5°~56.5°,介于Mohr—Coulomb理论和Roscoe理论计算得到的剪切带倾角值之间,而Arthur准则能更好的预测南海砂土的剪切带倾角值。
The digital image measurement technology is used to carry out the conventional triaxial test to obtain the deformation information each point of the sample surface during triaxial test,and analyze the shear deformation characteristics of samples.In this study,consolidation and drainage shear tests with different confining pressures and initial relative compactness were carried out on the soil from Shen Hu area in the South China Sea.The law of shear strength variation of sand was studied,and the law of shear deformation and failure of sand samples was emphatically discussed based on the digital image measurement system.The results showed that the sand in the South China Sea has different strain softening characteristics at different confining pressures and compactness.The failure types of the samples were all"single-type".The shear band began to form at about 1/2 of the peak shear strength,and formed completely at the strain softening stage.The measured inclination of the shear band varied between 53.5°and 56.5°,which was between the inclinations of the shear band calculated by Mohr-Coulomb and Roscoe theories,and Arthur criterion can better predict the inclination of the shear band.
作者
杜奇智
张红
程升
单红仙
DU Qizhi;ZHANG Hong;CHENG Sheng;SHAN Hongxian(The Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China;China Railway Major Bridge Reconnaissance&Design Institute Co.Ltd.,Wuhan 430050,China)
出处
《海洋湖沼通报》
CSCD
北大核心
2023年第6期27-33,共7页
Transactions of Oceanology and Limnology
基金
国家自然科学基金(41877223)。
关键词
南海砂土
数字图像测量系统
剪切带
密实度
South China sea sand
digital image measurement system
shear band
compactness
