Abstract:In order to study the secondary internal force caused by the support settlement of statically indeterminate structure under the action of creep, taking a five-span prestressed concrete continuous beam bridge as an example, the secondary internal force and the final internal force of continuous beam are calculated by using the method of conversion elastic modulus. On this basis, the influence of the secondary internal force on the distribution of the internal force of the continuous beam is further analyzed. The results show that when the support settlement occurs in the statically indeterminate continuous beam, a significant secondary internal force will be produced in the structure. The elastic internal force generated by the support settlement will decrease with time under the action of creep. Creep has the unloading effect on the elastic internal force produced by support settlement. The final internal force on the structure is about 45% of the elastic internal force. On the premise of satisfying the safety of continuous beam, the section size can be changed properly to reduce the stiffness of the bridge, which can save the cost and create more economic benefits. In practical engineering, the internal force distribution on the structure can be adjusted by applying the pressure or balance weight on the continuous beam to further reduce the influence of the secondary internal force caused by creep on the bridge structure.
