Stability Analysis Of High Embankment Of Slope Foudation

In recent years, the highways in mountain areas are constructed rapidly. A number of embankment on slope foundation which was found on soft soil layers will be the main problems for the construction of highway in the mountains. As for the lack of the systematic research on the stability of high embankment on slope foundation, based on Guangfozhao highway under construction, some methods such as FLAC3 D method, rigid block upper bound limit solution, and the finite element upper bound limit solution are used in this paper to study soft soil parameters' effects on the stability and failure mode of high fill embankment on slope foundation.Firstly, FLAC3 D is used systematically in this paper to analyze the stability and failure mode of high embankment on slope foundation combining with different parameters of soft soil layers. There are two failure modes:1.the broken line sliding failure along the surface of slope foundation and replacement filling soil layers;2.the broken line sliding failure which is along the surface of slope foundation and shear out from the top of back berm. The basal soft soil different parameters' influence on the deformation of high embankment on slope foundation under traffic and vehicle load, such as the internal friction angle, cohesion and elastic modulus are analyzed in this paper. The result shows that cohesion, internal friction angle and elastic modulus have little influence on the deformation.Secondly, based on the basic principle of the upper-bound theorem of limit analysis, velocity fields of high embankment on slope foundation under different failure modes are established. The program of solving safety factor is worked out by MATLAB. The safety factors of different failure modes are solved using the upper bound method of limit analysis. The result shows that the maximum error is 8.02%, and the minimum error is 3.73% by co MParison with the safety factors by FLAC3 D.Finally, based on the basic method of finite element upper bound solution, a program to solve the safety factor is worked out. Taking a si MPle slope as an exa MPle, the influences of mesh density and the number of plastic multiplicator are discussed in this paper. The results show that the mesh density has little effect on the calculation results and the larger the plastic multiplicator is, the more accurate the results are. But when the plastic multiplicator is greater than or equal to 24, the results are almost equal, and the effect on the calculation results is not very obvious. With regard to the K164+160-K164+280 section of the Guangfozhao highway under construction, the program is used to calculate the safety factor and the velocity field under different parameters. Co MParing with the calculation results of numerical simulation and rigid blocks upper bound method, it is found that the failure mode is coincide with the one calculated by numerical simulation, and the safety factors are slightly smaller than the results calculated by rigid blocks upper bound method. The results show that the limit analysis upper bound finite element method is more reasonable.