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。
Abstract
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 of ΔL/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
Key words
weakly over-consolidated clay /
direct shear test /
contact surface /
over-consolidation ratio /
shear strength /
hyperbolic model
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参考文献
[1] 李广信. 高等土力学[M]. 2版. 北京: 清华大学出版社, 2016.
[2] 胡黎明, 濮家骝. 土与结构物接触面特性研究[J]. 工程力学, 1998, 15(增刊3): 358-363.
[3] POTYONDY J G. Skin Friction Between Various Soils and Construction Materials[J]. Géotechnique, 1961, 11(4): 339-353.
[4] 张治军, 饶锡保, 丁红顺,等. 不同含水率泥皮对接触面力学特性影响的试验研究[J]. raybet体育在线
院报, 2007, 24(5): 60-63, 67.
[5] 夏红春, 周国庆. 土-结构接触面剪切力学特性及其影响因素试验[J]. 中国矿业大学学报, 2010, 39(6): 831-836.
[6] 胡黎明, 濮家骝. 土与结构物接触面物理力学特性试验研究[J]. 岩土工程学报, 2001, 23(4): 431-435.
[7] 卢廷浩, 王 伟, 王晓妮. 土与结构接触界面改进直剪试验研究[J]. 沈阳建筑大学学报(自然科学版), 2006, 22(1): 82-85, 99.
[8] 朱俊高, 汪 淼, 黄 维, 等. 钢-土接触面位移与强度特性直剪试验[J]. 河海大学学报(自然科学版), 2021, 49(3): 265-271.
[9] 张 磊, 刘 慧, 王铁行. 固结与不固结条件下黄土-混凝土接触面剪切试验[J]. 岩土力学, 2018, 39(增刊2): 238-244.
[10] GB/T 50123—2019,土工试验方法标准[S]. 北京: 中国计划出版社,2019.
[11] 汪 优, 任加琳, 李 赛, 等. 土-结构接触面剪切全过程本构关系研究[J]. 湖南大学学报(自然科学版), 2021, 48(3): 144-152.
[12] 汪 优, 李奕金, 谭 伟, 等. 考虑结构表层粗糙度的混凝土桩-黏土界面剪切特性试验研究[J]. 中南大学学报(自然科学版), 2019, 50(10): 2502-2509.
[13] 卢照亮,刘晓玲,郑云飞,等.斜拉索表面粗糙度对干索驰振的影响[J]. 工程力学,2017,34(增刊1):174-178.
[14] 罗耀武, 胡 琦, 凌道盛, 等. 桩-土界面特性对砂土地基中抗拔桩承载特性影响的模型试验研究[J]. 岩土力学, 2011, 32(3): 722-726, 732.
[15] CLOUGH G W, DUNCAN J M. Finite Element Analyses of Retaining Wall Behavior[J]. Journal of the Soil Mechanics and Foundations Division,1971,97(12):1657-1673.
[16] DESAI C S, MA Y. Modelling of Joints and Interfaces Using the Disturbed-State Concept[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1992, 16(9): 623-653.
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