| With the rapid development of China’s social economy and the great progress of urbanization,the construction of infrastructure in the western region has achieved unprecedented development opportunities.However,under the limit of the special geological environment in the West and the unique terrain and landform conditions,it is inevitable to encounter a lot of high filling and deep excavation projects,resulting in a large number of high filling slope stability problems.Compared with the previous engineering filling slope engineering,the current high filling slope deformation and destruction mechanism increasingly complex;in particular,the study of slope stability of high filling under different rainfall conditions is deficient,and lead to excessive deformation or instability accidents have occurred,on the basis of existing results,to improve the accuracy of analysis of the stability of the high embankment the slope,become a key problem in many scientific research workers to be.This paper relies on a civil airport project of Longnan state,first of all,through the unsaturated soil test was carried out on three axis than on the soil water characteristic curve experiment with different filler,in order to its relative permeability coefficient is predict;secondly,based on the system analysis of method on stability analysis of high fill slope,discussed the advantages and disadvantages of commonly used analysis methods of slope stability and applicable conditions;thirdly,the stability of the high embankment slope under different rainfall conditions were analyzed using Plaxis and GEOstudio,obtained some beneficial results and understanding.Specific research contents and results are as follows:1.By analyzing characteristics and difficulties in this project,triaxial test of unsaturated soil and other laboratory soil tests,determined the shear strength and SWCC and permeability coefficient of different mixture ratio of filling materials,and provide accurate parameters for calculation and analysis.Based on SWCC obtained by experiment,the relative permeability coefficient of the mixed filler under different suction is reasonable predicted;2.The filler of different mixture,suction in the lower level,with the ratio of permeability effect is not obvious;but with the increasing of suction,soil saturation constantly decreases,soil rock ratio of 2:8 filler permeability coefficient decay rate is significantly greater than the earth than 4:6 filler;in the later process of saturated,this difference decreases gradually;3.Based on the finite element software,the numerical analysis model of high fill slope is established,and the slope stability under different working conditions,different filling,different slope rate and different slope height are analyzed.The results showed that packing ratio is higher embankment slope stability of 4:6;at the same time,with the increase of high slope ratio and slope,the slope safety coefficient decreases gradually,in addition,the upper slope rate changes impact on the overall stability.4.Analysis stability of the high embankment slope under the conditions of maximum rainfall,different rainfall intensity,rainfall duration and rainfall early,found in the history of the largest slope under rainfall conditions,showing well stability;with the increase of rainfall intensity,the slope stability decreases rapidly increase with time node forward;with the increase of rainfall duration,safety coefficient changes in form of three stages,namely firstly slowly,then rapidly decreases,finally tends to be stable. |
