Finite Element Analysis About Reinforced Earth Of The Backfill To The Back Of Bridge Abutment

As a kind of new-type geotechnic material , geosynthetics is widely applied in reinforcement of soil body engineering in recent years. In backfilling project of abutment and culvert, the bearing capability of backfilling material can be enhanced greatly by setting geosynthetics as reinforce in backfilling body,and the lateral and vertical deformation can be restricted, it can still reduce the asymmetric sedimentation of backfilling body. By this way, many practical problems of backfill abutment and culvert could be resolved effectively.The gravel is one of the most common materials for abutment backfilling. The gravel backfilling material with well gradation could be compacted easily , it has good hydro-stability and high strength. The backfilling body with gravel material has good globality and stability, the deformation and sedimentation on the top surface of backfilling body could be reduced. Eolian sand is composed of river-alluvial fine sand, silt soil and clay particle with different content. It has poor cohesive strength, low percent moisture content, large mobility and bad particle activity in surface. Its gradation is not well and it's hard to form a whole body. For these reasons, it should be treated before being used as backfilling material. Eolian sand is macro-scope existed at western area in China. Using eolian sand as backfilling material in this area can obtain raw materials locally, reduce the cost of project, it can accelerate the progress and guarantee the construction period as well.In this paper, the principal engineering diseases about backfilling project and their genesis are analyzed, and the methods to solving these practical problems at present are summarized. By using ABAQUS, a current general finite element calculation software, this paper established gravel backfilling model and eolian sand model depending on actual project, setted geosynthetics with different distance as reinforce in backfilling body, and proceeded finite element numerical simulation calculation,analyzed the effects of different reinforce distance on stress,strain,globality and stability and compared the effects of same reinforce distance on the two sorts of different backfilling bodies. The results indicate that setting geosynthetics as reinforce can improve the globality of backfilling body,restrict the lateral and vertical deformation and asymmetric sedimentation,reduce the pressure of soil body to abutment and its subordinate structures, the effect of reinforcement in gravel is better than in eolian sand.