The Effect Of Rainfall In Guizhou Airport High Embankment Slope Study On Deformation Failure Mechanism And Stability

Since 12th Five-Year since the national planning, the airport all over the Yunnan Guizhou Sichuan tibet. The airport is mainly distributed in the middle and low hills, hills and other places, and the engineering geological conditions are more complex and complicated, the main engineering geological problems of the airport is the foundation of uneven settlement and slope stability. With the completion of the southwest mountain airport, after one or two years of work at the airport are different degrees of deformation and destruction of signs, the problem of the airport, to the airport operational security has brought potential threats.The to an airport, Guizhou Province as an example, starting from the unsaturated theory, the saturated unsaturated theory, combined with research area of engineering geological conditions and fill slope, slope structure characteristics, material composition, slope deformation failure characteristics, soil and rock mixture permeability characteristics, analysis the influence of the high fill slope deformation damage, and the main factors of the deformation failure mechanism and failure mode, and through the numerical simulation and analysis of the change of seepage field. At the same time, the monitoring data were fitted by numerical simulation. On this basis, through qualitative and quantitative analysis of the variation of high fill slope stability.The main research contents and results are as follows:(1) On the basis of preliminary investigation data, to carry out field investigation sampling and deformation monitoring data collect, identify the high fill strong deformation zone size and boundary characteristics and structural characteristics of slope, deformation characteristics of basic information.(2) In the range of seepage deformation, the seepage water quantity is linear with the change of the hydraulic gradient, and the permeability coefficient of soil rock mixture increases exponentially with the increase of stone content. When the stone content is less than 50%, the permeability coefficient is smaller than the slope of the stone. When the stone content is more than 50%, the permeability coefficient changes with the stone content of the curve slope is larger, it shows that the permeability coefficient increases significantly; the hydraulic gradient is located between 0?15, 30%,50% soil rock mixture will not occur seepage deformation. When the stone content is 70%, the hydraulic gradient reached 9.15 after the occurrence of piping.(3) The deformation and failure mechanism of embankment slope is divided into shallow slide mechanism and deep deformation mechanism. Two types of deformation and failure mechanisms were soaked in groundwater softening slope, rainfall caused by the shallow saturated with development, groundwater uplift and shallow saturated zone through three stages. The shallow sliding collapse of groundwater sources in space for conducting water, the groundwater properties bias in perched water; and the deep deformation is mainly affected by the channel region groundwater runoff. Rainfall is the main factor that causes the rise of groundwater level and the saturation of the shallow layer. The failure mode can be summarized as follows:the progressive deformation and slip burst damage.(4) Using the SEEP program module analyzes the change of seepage field of high fill embankment slope and deformation. Due to slope saturated mainly through six stages:1) local surface saturation stage; 2) the surface saturated zone through stage by rainfall infiltration:due to surface scattered saturated zone number increasing, area gradually increased, in the slope surface and slope zone, saturated zone gradually through; 3) channel of underground water and saturated zone through stage; 4) at the foot of the underground water level uplift stage,5) slope at the foot of the saturated zone goes on stage; 6) saturated zone through stage.(5) Combined with the monitoring results, the deformation characteristics and failure causes are analyzed, and the SIGMA program modules are used to simulate the monitoring results and the actual deformation and failure characteristics, and the practical results are obtained.(6) The mechanical factors that affect the stability of the slope are analyzed, and the stability of the airport slope is analyzed qualitatively and quantitatively. At the same time, the change law of slope stability with the change of rainfall time is studied. The calculated results are in agreement with the actual results.