Elastic-plastic FEM Simulation And Analysis On Culvevt Construction

The culvert is the works buried under the fillings, which is often used in Hydraulics, Communication, and Water supplying engineering. The whole procedure of construction, including foundation-pit excavation, the body construction and foundation-pit filling, was simulated and analyzed by using elastic-plastic FEM procedure programmed by myself. And the laws of stress field and displacement field were obtained.In the simulation and analysis on culvert construction, the method of foundation-pit excavation layer by layer and step by step was used, i.e. the method that makes the surface of excavation have no stress, when the elements were excavated gradually in period of construction. At this process, the state of soil is unloading, the laws of stress field and displacement field with the depth of excavation were studied. Based on the obtained stress field and displacement field after the excavation was completed, by using of the newly increased filling-elements' gravity and the grinding force, the simulation of the construction of body of the culvert and foundation-pit's filling layer by layer had also been done in this dissertation. The simulation not only reflected the laws of the filling soil's loading and deformation when it lied in reloading state, but also the real interaction between the foundation, the culvert and the body of soil was simulated and the relationship of them was quantified.Using the finite element method (FEM), the simulation and analysis on this construction process were carried on, and the different stress state of soil at different construction period was rendered. And the influence of differentstress paths (foundation excavation-unloading & excavation filling-reloading) on the stress and the displacement was also reflected and researched. The law of non-linear constitutes of soil was presented in the simulation and analysis. Thus, the general laws of changing stress and strain or settlement at these two different states (unloading increasingly and reloading increasingly) were obtained and offered objectively.So, the field of stress and displacement obtained through this method of simulation was real and objective for the analysis and design of culvert structure. The simulation of the whole procedure of construction was very vital in construction practice. All these laws were good references to construction of the works like culverts and the most important basis for construction design and structural design.