弱超固结黏土-混凝土接触面力学特性直剪试验研究  

Direct Shear Test on Mechanical Properties of the Interface Between Weakly Over-consolidated Clay and Concrete

作　　者：刘蔚 饶锡保[1] 李浩民 LIU Wei;RAO Xi-bao;LI Hao-min(Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]长江科学院水利部岩土力学与工程重点实验室,武汉430010

出　　处：《长江科学院院报》2023年第10期131-136,141,共7页Journal of Changjiang River Scientific Research Institute

摘　　要：为探讨黏土的超固结比对黏土-混凝土接触面力学特性的影响,利用直剪仪对不同弱超固结黏土与混凝土的接触面进行直剪试验。试验成果分析表明:黏土的超固结比从1增加到2时,接触面的黏聚力增大40%,内摩擦角增大38%。弱超固结黏土与混凝土接触面尚未剪切破坏时,剪应力-剪切位移曲线符合双曲线模型;接触面剪应力达到抗剪强度后,接触面破坏,进入滑动摩擦不收敛状态。接触面的抗剪强度、初始切线劲度系数与破坏比随着超固结比的增大而逐渐增大;接触面的抗剪强度符合摩尔-库伦破坏准则。建立了黏聚力、内摩擦角、ΔL/τ-ΔL关系中的斜率和截距与超固结比的经验公式,结合摩尔-库伦破坏准则,又建立了简单的接触面本构模型。并用试验数据验证其合理性,可供相关工程参考。To investigate the impact of the over-consolidation ratio of clay on the mechanical properties of clay-concrete interface,direct shear tests were conducted on different interfaces between weakly over-consolidated clay and concrete.Test results revealed that an increase in the over-consolidation ratio of the clay from 1 to 2 led to a 40%increase in the cohesion of the interface and a 38%increase in the internal friction angle.The shear stress-shear displacement relationship followed a hyperbolic model before the interface reached shear failure.Once the shear stress reached shear failure,the interface fractured,entering a divergent state characterized by sliding.With a higher over-consolidation ratio,the shear strength,initial tangential stiffness coefficient,and failure ratio of the interface gradually increased.The shear strength of the interface conformed to the Mohr-Coulomb failure criterion.Empirical formulas were developed to describe the relationship between the over-consolidation ratio and the cohesion,internal friction angle,and slope and intercept within the coordinate system ofΔL/τ-ΔL.These formulas were combined with the Mohr-Coulomb failure criterion to establish a simple constitutive model for the interface.The rationality of this model was verified using the test data,making it applicable as a reference for other related engineering projects.

关 键 词：弱超固结黏土 直剪试验 接触面 超固结比 抗剪强度 双曲线模型 

分 类 号：TU411[建筑科学—岩土工程]