为了研究酸腐蚀作用对桩-土接触面剪切特性的影响，利用大型多功能界面剪切仪，进行了砂土与被硫酸加速腐蚀0、31、93、154 d的混凝土板之间接触面剪切试验，量测了不同腐蚀时间的混凝土与砂土接触面的剪切应力和剪切位移关系。研究结果表明：砂土与硫酸腐蚀混凝土接触面剪切应力与剪切位移符合双曲线模型，接触面剪切破坏符合摩尔-库仑准则。随着腐蚀时间的增加，接触面黏聚力减小，摩擦角、剪切强度以及达到峰值剪切应力所需的剪切位移增大，接触面的破坏趋向于土体自身剪切破坏。取未腐蚀混凝土与砂土接触面达到峰值剪应力时的剪切位移为基准，对该位移对应的不同腐蚀时间下混凝土与砂土接触面的剪切应力进行对比分析，发现腐蚀5个月后的剪切应力要小于未腐蚀时的剪切应力。按双曲线模型对试验测得的接触面剪切应力和剪切位移关系进行了拟合，获得了该模型中的参数，为进一步进行数值模拟提供参考。

To investigate the effect of sulfuric acid corrosion on the mechanical behaviors of the pile-soil interface, large-scale direct shear tests were conducted on the interface between sand and concrete slabs under corrosion of 0, 31, 93, 154 days in sulfuric acid solution. Tests measured the relationship between shear stress and shear displacement of sand-corroded concrete interfaces after different corrosion durations. Experimental results indicate the hyperbolic relationship between shear stress and shear displacement. The shear failure of interface agrees well with the Mohr-Coulomb strength failure criterion. As the corrosion time increases, the cohesive force on the interface decreases, and the friction angle of interface, the shear strength and the shear displacement at the peak shear stress increase. Sand concrete interface failure tends to fail by sand itself under shearing. The shear displacement corresponding to the peak shear stress at interface between uncorroded concrete and sand is referred to as a standard. By comparing the interfacial shear stress with different corrosion times with the standard shear displacement, the shear stress after 5 months of corrosion is found to be smaller than that of uncorroded one. Finally, hyperbolic model is established and its parameters are obtained through the fitted relationship between tested shear stress and shear displacement, which provides a reference for further numerical simulation.