Study On Embankment Settlement Of High Fill About Suining Airport

For Suining Airport, due to the venue complex topography conditions the highembankment core of the project main problem is differential settlement and slopestability. For differential settlement field area, it is needed to analysis and calculationsettlement of the original foundation and filling body. It expects certain guidingsignificance for engineering construction.The length designed of Suining airport runway is2200m and tne width is45m.The length of Safety Road on both sides is300m. The average width of soil surfacearea on both sides is about90m. The elevation of airport reference point designed is345m.Criss-cross the valley in the region and undulating terrain, the greater fill heightis at the southern tip in the Hujiawan area, with a maximum of up to49meters. Itsslope ratio is1:2.The main contents and results are as follows：Research laboratory triaxial shear tests on the shear properties of the mudstonegravel soil.It is found that shear strength data is larger obtained from tests. Cohesionis significantly higher. The possible causes are: mudstone was originally formed bythe sticky substance cementation, the cosmid increased broken and the compactedgravel soil particles may exist "chimeric force". These reasons make cohesion larger.By compression settling tests it is found that in different conditions of moisturecontent sedimentation rate is significantly different.It meets certain function law andachieve a better fit.By conventional layered summation calculation it shows that the five sections of theoriginal foundation largest settlement is in0.75~1.21m.The time is0to7.1years forfive sections of the original foundation normally consolidated50%. The time ofconsolidated90%is0to23years. The consolidation required time is longer and it isnecessary to deal with the original foundation. For example, when1-1profiles’originalfoundation soil compression modulus reach20Mpa or more original foundation soilsettlement is only0.143m. It shows that ground treatment achieve good results.Combined with compression settling tests and according to the monthly rainfallfor the whole year and rainfall depth of the filling body, the filling body is dividedinto three. Layers of different moisture content correspond different compressionsettling tests. Fill settlement amount calculated by the fitting formula and thecalculation results show that: the profiles filling the maximum settlement is from0.46to0.76m after1year. Differential settlement of some point of each section certain is more than3‰. Total settlement and differential settlement are larger. The resultsshow that the density of the filling90%of the body can not meet the engineeringrequirements. Density should be controlled at93~98%and density of slopes groovearea is about98%.Rainy season settlement is41to48%of the total annual totalsettlement amount. The effect of rainfall on the filling is subsidence and it is needed tofill foundation drainage.Groundwater level changes filling settlement variation of2.2to4.0%, the smaller effect.With the application of GeoStudio in SIGMA/W module,analysis and calculationthe settlement of the stress-strain model. The horizontal displacement of each sectionfilling body is more than75%of the foundation horizontal displacement amount. Theoriginal foundation vertical displacement is more than63%of the total verticaldisplacement. The results of finite element analysis is similar to the sum of thehierarchical method. When the cross-section of the original foundation compressionmodulus is more than12Mpa, the original foundation settlement amount issignificantly reduced. Model analysis shows that rainfall filling body verticaldisplacement increase from3.3to8%. The influence is strong and results is in linewith the results of the fitting formula. Compared to layered summation the obtainedoriginal foundation settlement and finite element numerical results except5-5Settlement profiler difference is0.16m,a bit larger, other cross-sectional difference isin0.03~0.07m, smaller difference. It is finited that FEM and hierarchical summationmethod has higher accuracy and the corresponding reference value.