Experimental Study On Dynamic Reinforcement Of High Filled Expansive Soil Foundation In Ankang Airport

Expansive soil is a kind of high-plasticity clay that absorbs water easily,and water loss is easy to shrink.Due to the irregular distribution of cracks in expansive soils and soils,in addition,the destruction of expansive soil is shallow,gradual,and long-term latent.It often leads to various engineering disasters and brings huge economic losses to the city construction.At this time,the filling height and filling area of the high fill project at Ankang Airport are also one of the larger projects in the country.The reinforcement of high-filled foundations is the key to ensure the smooth progress of the filling project.Therefore,strengthening Ankang’s relocation of airport foundations has important theoretical and practical significance for the Ankang relocation project.Through on-site surveying,accessing a large number of documents,and combining geotechnical investigation data,a representative 3 pilot areas were selected in the site area.Three types of technology,namely ordinary dynamic compaction,dynamic replacement,and vibrating immersed sandstone compaction piles,were respectively used to reinforce the foundation of the expansive soil test area in the Ankang relocation airport.The basic physical mechanics index test,compression test,direct shear test and other laboratory tests of the soil of the expansive soil before and after the three kinds of process reinforcement are carried out to provide a theoretical basis for the selection of the best process.From the results of indoor tests,the compressive modulus and shear strength of the three types of processes have been significantly improved compared with natural expansive soils.Secondly,the field test of shallow slab load and heavy-duty dynamic penetration was carried out to study and analyze the change of foundation bearing capacity and soil compactness before and after reinforcement.Then the settlement deformation of the three processes was calculated by FLAC3 D and the stratified summation method.The settlement deformation law of the reinforced subgrade soil was analyzed.Finally,parameters such as compression modulus,internal friction angle,and settlement deformation of foundation are selected as evaluation indicators.The entropy weight method was used to screen out the best technology for the replacement of the dynamics of the expansive soil foundation of the Ankang Airport,providing some scientific guidance and reference value for the high filling project in the later period.