以淤泥土为原料土,通过自制混凝土试块和固化淤泥土试样,利用室内直剪仪对固化淤泥土–混凝土界面进行剪切力学试验,探究试样养护龄期、固化剂种类及含量、界面粗糙度等因素对剪切力学特性的影响。结果表明:固化剂种类及含量、淤泥土的含水量及固化程度对界面剪切力学行为产生影响;在外加剂的影响下,用SiO2固化淤泥土的界面剪切强度、黏聚力均大于MgO;MgO掺量为12%时,固化淤泥土的剪切界面内摩擦角最大,其次分别是掺量为12%和6%的SiO2,MgO掺量为6%时最小;在对双曲线模型进行修正的基础上,建立了不同养护龄期下固化淤泥土–混凝土界面的剪切双曲线型经验公式;研究结果可为软土地区预制摩擦桩的设计与施工提供参考。
Using silt soil as a raw material, the study aims to investigate the impact of curing age, type and content of the curing agent, and interfacial roughness on the shear mechanical properties of the silt soil-concrete interface. Concrete specimens and cured silt soil specimens were self-made and then subjected to shear mechanical testing using an indoor straight shear apparatus. The results indicate that: The type and content of the curing agent, as well as the curing age, affect the water content and degree of curing of the silt soil, thus influencing the interfacial shear mechanical behavior. Silt soil cured with SiO2 exhibited greater interfacial shear strength and cohesive strength compared to that cured with MgO under the influence of admixtures. The internal friction angle at the shear interface of the cured silt is largest at 12% MgO doping, followed by 12% and 6% SiO2 doping respectively, and is smallest at 6% MgO doping. An empirical formula of the shear hyperbolic type for the cured silt-concrete interface at different curing ages was established by incorporating the corrections made to the hyperbolic model.These results can provide valuable references for the design and construction of precast friction piles in soft soil areas.
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