Effect of Subsoil Replacement in Frost-Sensitive Areas on the Frost Deformation of Channel

Abstract

The water content of the subsoil is one of the main factors affecting the subsidence of the channel bank slopes, the looser the soil quality of the bank slopes, the greater the water content, the greater the deformation of the channel bank slopes, the use of non-freezing and expansion sensitive materials to replacethe bank slopes with wet subsiding soil is an effective way to solve the problem of frequent freezing and expansion of the channel bank slopes. In order to solve the problem of frozen expansion damage caused by groundwater level change and repeated freezing and thawing of seasonal frozen soil foundation in the cold and dry irrigation area in northwest China, ABAQUS software was applied to simulate the influence of the replacement of channel subsoil materials on the temperature and strain fields of the foundation by establishing a finite element model. The results show that: after the soil foundation in the frostsensitive areaof the channel is refilled with 30cm, 50cm and 70cm thick gravel and fine sand respectively, the frost deformation of thechannel bank slope and foundation is obviously reduced, an the reduction effect of gravel on the frost deformation is better than that of fine sand; with the increase of the thicknessof the refill, the reduction of frost deformation is also on adecreasing trend, and the influence of the channel subsoil refill on the temperature field of the foundation is smaller, but the subsoil will make the temperature field and strain field of the bank slope after the refill. After refilling, the frozen expansion displacement of the bank slope can be dissipated,which can significantly improve the deformation and stress concentration phenomenon on the channel seepage control lining structure. The research results can provide theoretical basis and technical support for the anti-freezing and expansionstructural modification of channels in permafrost areas.