关键词: 冻土-混凝土桩基, 细粒含量, 峰值强度

Abstract: The shear characteristics of the frozen soil pile foundation interface have a significant impact on the stability and long-term service life of traffic engineering in frozen soil areas. This article studies the influence of fine particle content on the mechanical properties of the interface between frozen soil and concrete pile foundation through negative temperature direct shear tests.The research results show that the stress and displacement curve sample all show the stress softening model. The peak interfacial shear strength and ice bonding strength increase with the increase of fine grain content, and the residual strength has little fluctuation with the change of fine grain content. With the increase of fine particle content, the contribution of ice cementation strength to the interfacial shear strength of frozen soil and concrete gradually increases. The peak strength and residual strength of the samples increased linearly with the change of normal pressure, and the intensity of 50kPa to 100kPa increased sharply than that of other pressure intervals. The peak cohesion increases with the increase of fine particle content, and the residual cohesion decreases with the increase of fine particle content. The calculation formula of interface shear strength between frozen soil and concrete is established and its accuracy is verified.

Key words: frozen soil-concrete pile foundation, fine grain content, peak intensity