Stability Study On High Filled Slope Of Collapsible Loess

This research is on the stability analysis of high-filled slope with collapsible loess. First of all, according to its failure characteristics, the high-filled slope deformation and failure mechanisms of collapsible loess are analyzed. Secondly, based on the monitoring data a numerical analysis on the construction process of high-filled slope is performed by FLAC3 D and the deformation regularities on horizontal and settlement are summarized. Comparing the calculation results to the monitoring data, it shows that the model adopted in simulation is suitable for the project construction. Finally, strength reduction method and Bishop method are applied to calculate the safety factor of the project. Compare the results of two methods and evaluate their acceptance in analyzing the high-filled slope of collapsible loess. The main achievements are as follow:(1) By analysis on the deformation characteristic, the deformation mechanism of collapsible loess is summarized. The deformation consist of three progresses, which are uneven settlement of nature base layers, tension deformation of filled layers and the deformation of high-filled slope. This is the theoretical base of simulation on the project.(2) Based on a high-filled construction project of an airfield, a model is presented and the simulation is performed by FLAC3 D. The results indicate that with the increase of embankment height, both the settlement and the horizontal displacement of nature base and filled layer are constantly increasing and can reach stability finally. For the same filled layer the vertical and horizontal displacements are different in different positions. It shows that the deformation is significantly affected by the original terrain and the thickness of filled layer.(3) An analysis is performed by comparing the simulation results to the monitoring data. Both the vertical and horizontal displacement values are not exactly the same, but there is a same trend. It shows that the established model in simulation is feasible and the finite difference software can be adopted for deformation simulation on high-filled slope of collapsible loess;(4) Both strength reduction and Bishop method are chosen to calculate the safety coefficient of loess high-filled slope and their results are 1.42 and 1.49 respectively. Both meet the specifications requirements. By comparing their complexity and accuracy, strength reduction method is recommended for its clearer meaning, simpler process, more adaptable and more reliable.