The FEM Analysis Of The Single-Bridge In The Grade-â…  Highway

Nowadays , based on the transition of construction's condition in our country, more and more double-bridge in the Grade-I highway has been rebuilded or changed design into single-bridge because of the change on design of highway and kinds of single-bridge's merits. However, there are still some of subjects about design of single-bridge in the Grade-I highway are worth researching.Therefore, this dissertation mades numerical simulation about main beam and transom unit in single-bridge in the Grade-I highway and studys different effects of actions on them by using finite element analysis method and joining with design of actual engineeringBased on one building engineering, the main beam's three dimensional solid model of single-bridge is given. All kinds of effects of actions including normal stress, shear stress, principal compressive stress, principal tensile stress, moment and shearing force which are caused by gravity load, action of automobile brake force, action of shrinkage and creep ,action of gradual rise in temperature and so on are analyzed against the features of structure and actions. Based on one rebuilding engineering, the three dimensional solid model of main beam with transom unit is established. Effects of gravity load, unilateral lane load and action of gradual rise in temperature are analyzed, especially, transverse regularities of distribution and parameter of transom unit.The finite element numerical calculation's analysis result shows it is necessary to make the three dimensional computation regarding single-bridge in the Grade-I highway. Speaking of the main beam structure, the automobile brake force's action is on the small side, but the concrete shrinkage and creep's action is on the big side. Action of concrete shrinkage and creep is easy to induce tensile stress at section's upside of support's around,and makes this part of main beam in tensile condition , further. Speaking of the transom unit, its height is a significant design parameter which can influence stress and force obviously. Increasing the height of transom unit can reduce transom unit's stress and increase its force. Therefore, it should be to consider stress and force synthetically to choose transom unit's height and check crack.