Experimental Research on the Bearing Capacity of the Widening Segment of Precast Small Box Girder
Liqiao Xia, Qian Li, Han Ding, Zengshun Tiandownload PDF
Abstract: Widening the existing expressway is an important way to solve the problems like road traffic congestion and level of service declining in the existing highway network. Besides, for the highway with large traffic volume and lack of detour roads, it is inevitable to open to traffic at the same time of construction. Taking a 20 m precast small box girder bridge widening project as the research object, the ABAQUS finite element entity model of the whole bridge and full-scale segment experiment is established, and the boundary conditions and loading force values of the segment model are determined by the similarity analysis. The numerical simulation calculation of the deflection difference between both sides of the joint and the joint reinforcement strain of the full-scale segment test model is performed, and results are compared with the experimental measured values, so as to verify the rationality of the finite element model. Moreover, this research further studies the shear transfer mechanism and bearing capacity of concrete joints with the finite element calculation, and the force-displacement curve of concrete joint loading in whole process is calculated. According to results, the early strength of concrete develops rapidly, while the deflection difference on both sides of the joint drops rapidly, and the deflection difference basically remains unchanged after 8 hours of casting. The shear transfer of joint concrete in the overall analysis model and section test model develops rapidly in the early stage, since then tends to be stable gradually. Results of the bearing capacity test describe that when the bottom reinforcement of the joint reaches the tensile strength and the deflection of the joint increases rapidly, the ultimate bearing capacity could be reached, and the most unfavorable part of the test joint could bear 17 times of 55t wheel load. It is demonstrated that the traffic control scheme of closing and widening the joint adjacent to the lane in the first three days could ensure the reliable casting performance of the concrete joint when the traffic is not interrupted. The research results would provide technical guidance for the design and construction of the same type of bridge.
Precast Small Box Girder, Splicing Technology, Segment Experiment, Shear Value, Deflection Difference
Published online 2/20/2021, 9 pages
Copyright © 2021 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Liqiao Xia, Qian Li, Han Ding, Zengshun Tian, Experimental Research on the Bearing Capacity of the Widening Segment of Precast Small Box Girder, Materials Research Proceedings, Vol. 18, pp 302-310, 2021
The article was published as article 37 of the book Structural Health Monitoring
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