Erection and field test of concrete arch bridge applying composite tube

The concrete arch ribs of the Jōshi Bridge were constructed by a new erection method called the concrete lining method with preerected composite arch (CLCA method). In this method, tubular steel arches are first erected. Next, concrete is filled into the steel tubes to form a composite arch. Finally, the concretefilled steel tubes are used like falsework and are encased in reinforced concrete to form the finished arch rib. Because the composite arch has excellent resistance against axial compression, the amount of steel used can be significantly reduced compared to conventional arch center and Melan arch methods. In this paper, the construction of the J6shi Bridge and the results of performance tests at each stage of the arch rib construction are described. In addition, the design technique of this method is discussed based on the test results.