不同含水率与剪切速率下超固结红砂岩粗粒土的剪切特性研究  

Reaserch on shear properties of overconsolidated red sandstone coarse grained soil under different water content and shear rate

作　　者：温树杰[1,2] 米天煜 袁心安 肖豪 谢志华[1,2] WEN Shujie;MI Tianyu;YUAN Xin'an;XIAO Hao;XIE Zhihua(School of Civil and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China;Jiangxi Key Laboratory of Environmental Geotechnical Engineering and Disaster Control,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西赣州341000 [2]江西理工大学江西省环境岩土与工程灾害控制重点实验室,江西赣州341000

出　　处：《江西冶金》2023年第5期432-438,共7页Jiangxi Metallurgy

基　　金：江西省“双千计划”创新领军人才资助项目(JXSQ2021003)。

摘　　要：为研究不同含水率和剪切速率下超固结红砂岩粗粒土剪切特性,利用Shear TracⅢ大型直剪仪对其进行固结排水剪切试验,研究含水率和剪切速率对不同超固结比土体剪切特性的影响规律。结果表明,不同超固结比的红砂岩粗粒土剪切特性在初始剪切阶段有很大的不同,正常固结土会先产生剪缩,而超固结土会产生不同程度的剪胀。随着含水率的增加,超固结土体的剪切变形特性由不同程度的剪胀现象转为剪缩;随着剪切速率的增加,土体的剪切变形特性由剪缩转变为剪胀;随着超固结比的增大,土体会逐渐产生剪胀现象。超固结比越大的土体,其抗剪强度越大,含水率和剪切速率对土体的剪切特性影响越小。在相同的超固结比下,随着含水率的升高,其抗剪强度呈先增后减的趋势,当含水率为8%时,抗剪强度最大;随着剪切速率的增加,剪胀效应越明显,抗剪强度呈先减小后增大的趋势。在剪切过程中,土颗粒间不同的移动方式,会影响剪切带的形成,从而导致产生不同的剪切特性。In order to study the shear properties of coarse-grained soils of overconsolidated red sandstone under different water content and shear rates,Shear TracⅢwas used to conduct consolidation drainage shear tests.The influences of water content and shear rate on shear properties of soils with different overconsolidation ratios are obtained.The research results show that the shear properties of red sandstone coarse-grained soils with different over consolidation ratios are significantly different at the initial shear stage.Normally consolidated soils will first produce shear contraction,while overconsolidated soils will produce different degrees of shear dilatation.As the increase of water content,the shear deformation characteristics of overconsolidated soil change from different degrees of shear dilatation to shear shrinkage.With the increase in shear rate,the shear deformation characteristics of the soil change from shear shrinkage to dilatancy.As the increase of over consolidation ratio(OCR),the soil will gradually produce dilatancy.As the greater the OCR grows,the greater the shear strength gets,and the smaller the influence of water content and shear rate on the shearproperties of soil become.At the same OCR,the shear strength increases first and then decreases with the increase of water content.The shear strength is maximum when the water content is 8%.The dilation effect becomes more obvious with the increase in shear rate.The shear strength decreases first and then increases with the increase in shear rate.During the shearing process,the different movement modes among soil particles will affect the formation of shear bands and lead to different shear properties.

关 键 词：红砂岩粗粒土 含水率 剪切速率 超固结比 剪切特性 

分 类 号：TU411[建筑科学—岩土工程]