Three-Dimensional Finite Element Model Analysis of An Arch Bridge

摘要

For the complexity and difficulty of modeling at local joints and the placement of prestressingtendons, 3D solid model is rarely used in nonlinear analyzing total bridges. This paper presents theanalysis process of a fly-bird-type Lohse arch bridge comprised of steel or reinforced concrete archrib, prestressed concrete box girders, reinforced columns and the hangers. The three-dimensionalmodel is established utilizing program Ansys for the friendly modeling and meshing tools, thenexported to text files and imported to midas' mct files，and analyzed utilizing program Midas for thesimulation of the construction sequence and under the range of loading applied. In the model thereare solid elements for concrete box girders, concrete arch rib and columns, plane elements for steelarch rib and link elements for prestressing tendons, the most complex and important zone are theintersections of girder and concrete arch ribs, it is similar to sculptural art to get the best node numberand element shape to reduce calculating time and get better result precision, the researcher spent a lotof time at it. According to the analysis result, the hangers forces are adjusted, the bearing forms arechanged, and the construction sequence is also modified. Especially the stress conditions of thecrossing zone between the box girder and arch ribs are brought forth factually.