Experimental Study On Soil Frost Heave And Horizontal Frost Heave Force Of Foundation Under One-dimensional Freezing Condition

The soils behind the foundations in cold area,such as the strip retaining walls and the ditches,usually undergo a dual restriction derived from the foundation rigidity and the vertical load.A frost heave thus occurs along the normal and lateral directions,and the frost heaveinduced force(FHF)occurs along the lateral direction during the soil freezing.The studies found in the available literatures rarely considered the frost heave as well as the lateral FHF under a dual restriction,and that significantly restricted the accurate estimation of the lateral FHF.In this study,a novel test system aiming at one-dimensional freezing under the restriction derived from the foundation rigidity and the applied load was initially developed.A series of tests was then performed on frost susceptible soils,and the main conclusions were as follows:The freezing-rate was enhanced substantially with the decrease in the temperature in cold end,and the increase in rigidity and applied load.Whereas the frozen depth was independent on the applied restriction conditions.Further,the ultimate frost heave increased with the temperature decrease in cold end and the applied load and the increase in the lateral restriction from foundation rigidity.The lateral frost heave near the warm end of the tested column increased with the decrease in the cold end temperature or the restriction rigidity and the increase in the vertical load,while the above-mentioned law was contrary at the locations near the cold end.Moreover,the obtained lateral FHF near warm end exhibited an increasing trend with the increase in the restriction rigidity or the vertical load.The relationship between the normal frost heave and lateral FHF or frost heave in test satisfied a parabolic function.The lateral frost heave reduced due to the increase in the normal frost heave.The lateral FHF increased with the increase in the normal frost heave near the warm end,while it decreased near the cold end.The measured moisture content profile showed that the moisture content near warm end increased with the decrease in the temperature in cold end or the applied load and the increase in the restriction rigidity.The reported study deepened the recognition of the frost heave mechanism under such dual restriction from foundation as well as the applied load,and which presented a substantial significance to accurate evaluation of the lateral FHF acting on the foundations in cold area.