NUMERICAL SIMULATION RESEARCH ON SEISMIC RESPONSE OF LOESS HIGH FILL FOUNDATION

In order to study the seismic response characteristics of high fill foundation after cutting hills to backfill ditchs in northern Shaanxi.we did a seismic simulation about the filling test area with true 3D model by using FLAC3D numerical analysis tool. Analyzed the stress and the plastic zone distribution characteristics of high fill foundation under the action of gravity stress and earthquake dynamics, and carried on the deep discussion about the dynamic deformation and dynamic response characteristic under the action of the earthquake. The study shows that in the area with large slope, the stress is relatively concentrated, and shear failure occurred more often. The earthquake action will aggravate the settlement of the filling area, and the existence of the combined surface is unfavorable to the earthquake resistance. Suggested that in this kind of high fill foundation engineering, It is better to dig up the steps to reduce the slope and enhance the integrity of the fill soil and the original formation to improve the seismic performance of high fill foundation.