Research On Calculation Method Of Wet Deformation And Settlement Of Sand And Mudstone Filling In Chengdu Tianfu International Airport

Most of the various projects constructed in the southwest area require a large amount of fillers in the filling area because of the large topography of the site and the staggered excavation and filling.In order to save costs and reduce the pollution of waste soil materials,construction units often obtain materials on site and use soil materials with good surrounding soil properties as engineering fillers.The soil material used for filling will be saturated with water during the rainy season,resulting in deterioration of soil material properties,which can seriously cause deformation of the backfill area,and the structure on it may also be deformed or even unstable.The study of the strength,deformation characteristics and degradation laws of fillers under water saturation is of great value for practical engineering applications and scientific research.In this paper,relying on the Chengdu Tianfu International Airport construction project,with on-site sand and mudstone fillers as the research object,the gds large-scale triaxial test is used to study the wetting deformation of the sand and mudstone fillers,revealing the stress-strain curve characteristics of the sand and mudstone mixture in the dry and saturated state.The influence of wetting stress level on wetting deformation,the influence of dry-wet cycles on wetting deformation,explore the mechanism of wetting action,and study the law of wetting deformation degradation under dry-wet cycles.Through the analysis and summary of the project overview and monitoring data of Chengdu Tianfu International Airport,the influence of groundwater level on the settlement and deformation of the foundation is explored from the perspective of data statistics,the mechanism of wetting deformation is studied,the calculation method of foundation settlement considering wetting deformation is proposed,and the flight area is studied an overview of the settlement and deformation of the backfill area of the big railway(east district).Through the change of groundwater level with time in plaxis and the characteristics of the change of soil properties after wetting,we simulate the settlement deformation considering the wetting deformation,which proves that the wetting mechanism of sand and mudstone is mainly due to the softening and rearrangement of particles.Deformation,to verify the reliability of the semi-empirical mathematical formula that has an exponential relationship between wetting strain and wetting stress level.