Experimental Study On The Permeability Characteristics Of Airport Gravel Soil And Numerical Simulation Of Seepage Deformation Of Gravel High-fill Slope

The further implementation of the strategy of developing the western region undoubtedly injected a tonic into the infrastructure construction in various provinces and municipalities in the southwestern region from the top-level design level.The mountainous features of the natural landscape in the southwest of China determine that priority should be given to the structure of the air transport network in accelerating the laying of infrastructure networks.Therefore,the provinces and cities in southwest China ushered in the second round of airport construction tend.This makes deep,heavy and big foundation projects as well as deep excavation and high filling projects emerging continuously.Due to its high strength and low compressibility,gravel soil has been widely used in airport high-fill projects.However,the gravel soil particles is of different sizes and uneven grading,under the effect of high infiltration of groundwater,the fine particles filled in them may be carried away by groundwater flow and potential corrosion damage.Therefore,it is necessary to accurately grasp the permeability property of gravel soil and its engineering effects.Taking the Garze Airport as an example,this paper studies the infiltration characteristics of the airport filler through the field water injection and the infiltration model test.Combined with the numerical simulation,the change of the seepage field and the stability of the slope are comprehensively analyzed,and the effective control measures are put forward.The paper has made the following achievements:Through the geological survey and data collection of the selected study area,the geological background of the study area is understood,the research direction of the article is confirmed,and the research methods are determined on this basis as well.Through a series of experimental studies on the samples of the study area,the permeability coefficient,critical hydraulic gradient range and the infiltration deformation pattern of the study area were determined.When the original slope of the limestone fill area is larger than 13°,or the metamorphic sandstone Packing area of the original ground slope is larger than 8°,related measures should be taken to prevent infiltration deformation measures.On the basis of geological survey and experimental study,the typical section is simulated and the process of saturation and the change of stability under high permeable slope are analyzed.It is found that the foot of high fill slope is the weak link.It is suggested to use the permeable layer and blind ditch drainage at the bottom of the filling body to reduce the hydraulic gradient.At the same time,the slope foot should adopt the slope protection structure such as the filter layer to prevent the infiltration deformation.