Research On Symplified Calculating Model And Loaded Behavior Of Integral Abutment Bridges

The design of jointless bridges are basically depended on experience and observation. Moreover field-test on jointless bridges are scarce too. Since integral abutment is more widely used and researched among all kinds of jointless bridges, simplified calculating method, loaded behavior and field-test of integral abutment bridges are detailedly researched in the paper. The main achievements can be summarized as follows: 1. The paper presents different calculating model to simplify the calculating for the design of integral abutment bridges in different phase. Among those calculating models, a three-dimensional frame model is presented to analyze the behavior of bridge structure when traffic is permitted. 2. Considering the nonlinear effect of backfill on abutment, and the effect of superstructure, abutment and backfill on the length of the equivalent cantilever pile, a model to calculate the earth pressure acting on abutment and the length of the equivalent cantilever pile is presented in the paper. The application of the model is also discussed based on Shangban bridge, Yongchun county Fujian province China. 3. Based on the model above, an appropriative program—IABS is secondarily programmed based on ANSYS to calculate the earth pressure act on abutment and the length of equivalent cantilever pile. With the appropriative program—IABS, the effect of the stiffness of substructure on the earth pressure acting on abutment and the length of the equivalent cantilever pile are also discussed. 4. A field-test of Shangban bridge is conducted in the paper. And a finite element model for integral abutment bridges is presented based on the field-test. With the validation of relative examples, the calculated results using FEA model are on the whole in good agreement with the experiment results. Consequently it shows that the FEA model can be used to analyze the static and dynamic characteristics of integral abutment bridges. 5. The feasibility of three-dimensional frame model is compared with the FEA model above based on Shangban bridge. It shows that three-dimensional frame model have good feasibility and can be applied to the calculating for the design of integral abutment. 6. The loaded behaviors of integral abutment bridge under static and dynamic load are analyzed on the base of the field-test of Shangban bridge. With the FEA model above, the longitudinal and transverse load distribution and the effect of the stiffness of substructure on loaded behavior are also discussed. As a result, some advise for the design of integral abutment bridges are presented.