Consolidation settlement characteristics of soft foundation in seasonal frozen swamp regions

In order to study the characteristics of consolidation settlement and the influential factors of soil foundation in seasonal frozen swamp regions,the characteristics of consolidation deformation and loading conditions of soft foundation under the load of embankment fill,different treatment methods for soft foundation,soil stratum conditions,temperature changes,time effect and so on are analyzed based on the proposed field monitoring scheme.Analytical results show that soft soil settlement occupies over 80% of the total settlement,although the soft soil layer is not thick.During the whole winter,negative temperature has some effect on the consolidation settlement of soft soil foundation,and the difference mainly occurrs at the central separation strip and the shoulder of the road.The lateral displacement of soft foundation basically grows with the increase of load.The maximum displacement depth grows with the increase of thickness of soft soil stratum.In the frozen process,the lateral displacement of soft foundation happens within the frozen depth scope.The pore water pressure of soft foundation scatters unevenly.Packaged sand drain is a suitable improvement measure for soft foundation in seasonal frozen swamp regions.The frozen depth of the experimental area changes with time,and the maximum frozen depth is below 2.8 m from late January to early February.In the frozen process of embankment fill,the soil pressure around the central separation strip becomes smaller,but that close to the side slope gets larger.With the increase of fill load,the strengthening effect of geogrids becomes more and more obvious.The research results can provide a useful reference for the design of soft foundation in seasonal frozen swamp regions.