The law of soaking infiltration and collapse deformation in typical loess-paleosol series

In order to investigate the law of moisture migration and collapse deformation of the typical loess-paleosol series, on the basis of water immersion test of the large test pits of Xi’an North-airport intercity rail transit in the loess tableland of Weibei, the real-time in-site observation was adopted, the soaking infiltration and collapse deformation of collapsible soil layer under conditions of non water seepage hole were traced and tested. The results show that: The movement of water immersion is dominated by vertical movement in the early stage. The whole form is like a continuous increase of “weight” shape. As the water moves to the deeper layer (about 15.0 m), the horizontal movement begins to increase until it reaches the boundary of water diffusion angle; The infiltrating and saturation area appear like inverted “funnel” form; secondly, under the influence of water diffusion, settlement can be divided into the following stages: the initial soaking stage-the drastic collapsible stage-the collapsible stable stage-the dewatering pressure dissipation stage-the consolidation settlement stage-the settlement stable stage; The paleosol layer hinders the vertical penetration rate of water and promotes the lateral diffusion of the upper layer. The research results provide a solid foundation for understanding the water migration and the law of collapsible deformation of the typical loess-paleosol series, also guidance and reference for the future project construction in this area.