| Along with the in-depth implementation of the western development strategy and theneeds of the construction of the three-dimensional transportation network system in southwestChina, the construction of the airport in southwest entered a stage of rapid development.According to the incomplete statistics, there are dozens of airports that builted and underconstruction in southwest China. The common characteristics of these airport construction isthat the fill height is great and the earthquake intensity is high and the geological condition iscomplex in site and the repairation is difficulty after damage. Based on the12#high fill slopethat had slided in panzhihua, the paper analysed the sliding characteristics and slidingmechanism and sliding reasons of the slope; analysed and calculated the stability of the slidedslope and the reinforced soil slope that will have been formed after the recovery of runwaysurface, studied the comprehensive treatment engineering of this damaged slope.Main research contents and results:(1) Analysing the sliding mechanism and characteristics and sliding reasons of the slidedslope through the methods of field investigation and surveying and monitoring and geologicalanalysis. Calculating and analysing the stability of the slope at present and basal landslide bythe limit equilibrium method combined with the displacement monitoring data of the deephole and the surface in site. Through the analysis knows: loose and broken filling stratigraphicstructure, rich groundwater and plenty of rainfall, sliding traction of old landslide that locatedin the front of the slope, the action that the weight of the tall fill body, these are the maincauses of slope sliding; Slided slope and it’s basal landslide is still in a state of deformation atpresent.(2) Analysing and calculating the stability of the reinforced soil slope that will have beenformed after the recovery of runway surface by the limit equilibrium method and the finiteelement method. Through the analysis gets: the first common slope that will have beenformed after the recovery of runway surface adopting the slope rate of1:1.5and otherreinforced slope adopting the slope rate of1:0.5meet the requirements of the stability.(3) Analysing and researching the potential sliding surface of the reinforced soil slope bythe limit equilibrium method and the strength reduction finite element method. The resultsshow that the potential sliding surface of the reinforced soil slope locates in no reinforcementregion of the slope body under the condition of the reasonable vertical space of the geogridreinforced belt, and gradually move to the no reinforcement region that is far away from theslope surface, and this show that the petential sliding surface has the characteristic of “keepaway from the powerful and get close to the weak” after the slope reinforced.(4) Establishing the two-dimensional finite element model by the finite element softwareMIDAS/GTS, and analysing several important factors that affecting the stability of reinforcedsoil slope, and then optimizing calculation model combined with the above analysis. Through the calculation and analysis obtains: its almost no effect on the stability of slope when thereinforcement belt length is more than30m and the reinforcement belt’s vertical spacing isless than0.4m; The stress deformation of the geogrid reinforcement belt distributes in theform of “above small,under big”, and thus optimizes the calculation mode.(5) Studing the best measures of the treatmenting of the slided slope combined with it’scharacteristics and sloping reasons and sliding mechanism and the result of stability analysis.Through the analysis gets: using anti-slide pile engineering with prestressed anchor cable asmajor measure; using drainage engineering, reinforced soil filling, excavation and reducingload in partly, displacement monitoring of surface and deep hole as auxiliary measures, thecomprehensive control engineering measures on the basis of above are reasonable. |
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