Study On Reinforcement Technology With Multi-point Supporting Strengthening Flat Arch Bridge

In the arch bridges, the flat arch bridge which the rise-span ratio is smaller, which mechanics behavior has the girder bridge tendency, causing this kind of arched bridge reinforcement more difficult, the conventional arched bridge reinforcement technology cannot achieves the ideal effect. The paper mainly aimed at this kind of bridge, proposed the multi-spot support reinforcement technology. Its purpose is to through the additional support and the original structure together function, reducing the internal force of the original arch ring when the live load is on, improving force capacity.From influence lines of the internal force and reducing the bending moment, the paper analyzed the mechanism of the reinforcement technology, lay the basis theory for the reinforcement technology. The reinforcement design theory described the method how to determine the multi-spots, the principle of the prestressed elastic support structure, the intensity of the section and the theory of the bearing capacity, introduced the construction technology simply. In order to increase the bonding between the new and the older layer, the new layer was poured with expansive concrete. The experiment about the expansive concrete determined the best parameters combination of the intensity and the limit shrinkage .The study carried on the test of the multi-spot support reinforcement arch model which proportion is 1:10, through the comparison of the stress and strain level, bearing capacity and the crack development, verified the validity and the applicability of this reinforcement technology. Finally, from implementation of the project, the paper showed the design and technique of this reinforcement technology.The paper research, provided one method of reinforced the small rise-span ratio bridge. We used expansive concrete in the bridge reinforcement and the transformation, at the same time we proposed one kind of pre-stressed elasticity support structure creatively, solved coordinated distortion question between the new structure and the old ingeniously, and has guaranteed the effective joint between the new structure and the old. Strengthening experiment of model arch revealed the effect and the stress state of the supports in the reinforced structures, and researched the entire destruction process and the final failure mode of the reinforced structures.