Deformation And Stability Analysis On The Broken Stone Embankment In Ganzi Airport

With the rapid development of our country’s economy,the construction of infrastructure in airports,railways and highways in the western region is entering a new height.The terrain in the western region is dominated by mountains and hills,in the process of infrastructure construction,there will inevitably be a large number of high fill projects.Because of its high strength and small deformation,the gravel soil is widely used as a high quality filler,but the gravel soil particles are larger,and in the process of engineering practice,the particles are often mixed with large size particles size.,its physical and mechanical properties are greatly influenced by the particle characteristics and particle gradation.Therefore,the granule characteristics and gradation characteristics of gravel soil,it is necessary to study the physical and mechanical properties of gravel soil.The Ganzi airport is at an altitude of 4068 m,the flight area is 4C,the total amount of earth and rock excavation is about 58.5 million cubic meters,and the maximum filling height is about 109 m,which is a typical high altitude filling airport.The filler of the high embankment is mainly limestone filler and metamorphic sandstone filler.In this paper,the 5# gully high embankment in Ganzi airport is selected as an example,through laboratory tests and field trials,the particle characteristics and physical mechanics parameters of the filler of limestone and metamorphic sandstone in ganzi airport are tested and studied.Using numerical simulation and limit equilibrium analysis,the deformation and stability of high embankment are simulated and analyzed,and the following conclusions are drawn.1.The particle size distribution curves of coarse grain and granule soil were obtained,and the filler categories are divided.Among them,the limestone aggregates are hard rock mixture(A5),which belong to the graded improper filler.the metamorphic sandstone fillers are extremely soft rock and gravel mixtures(C4),which belong to the graded improper filler.2.The shear strength of the filler is larger,the cohesion value is larger,and the shear strength of the three axial stress state is obviously larger.The field shaer test results of limestone fillers :the cohesion force is 45 ~ 59 kpa,the internal friction angle is 36.1 ° and 36.5 °,the indoor large triaxial test:the internal cohesion force is 41 kpa the internal friction angle is 51 °;the result of the field large shear test of the metamorphic sandstone filling is 20 kPa,and the internal friction angle is 30.5°.3.After the dynamic compaction treatment of limestone fill,The deformation modulus of the composite foundation composed of rammed pier and rammed soil is 36.8MPa;when the limestone ground is used as cushion,the deformation modulus of composite foundation composed of ramming pier and rammed soil is 24.5MPa.4.The average shear wave velocity of limestone packing after dynamic compaction is 346m/s.The mean value of shear wave velocity is 315m/s after vibration compaction,and the category of foundation soil are II class.5.The slope stability coefficient of the slope of 5# gully high fill slope is 1.6,the corresponding slope foot horizontal displacement is 0.13 ~ 0.18 m,and the slope stability coefficient is 1.65 ~ 1.70 under the limit equilibrium method,and the slope is in the stable state.At present,the displacement of the slope is 40 ~ 98 mm,the displacement curve tends to converge,and there are no cracks in the slope,and no abnormal uplift and deformation on the toe of the slope.