Uniform Deflection in PCI Girder with Diaphragm Installation

Abstract

Keramasan Bridge 2 is a bridge with an age of more than 30 years, so it is necessary to review its feasibility and serviceability. Based on visual observations, there are signs of cracks in the transverse and longitudinal directions on the bridge floor. Based on the results of the loading test, it is stated that the deflection on the girder has exceeded the allowable deflection, and the cause of the longitudinal floor crack is caused by the non-uniform vertical movement of the girder. Based on this, it is necessary to strengthen the superstructure first before repairing the bridge floor. The strengthening of the superstructure is carried out by installing a diaphragm between the girders. The diaphragm is an angled steel profile of 100 mm x 100 mm with a thickness of 10 mm. To determine the number and position of diaphragms, two alternatives were analyzed. The first alternative is to add three diaphragms at every 6.275 m distance and the second alternative is the diaphragm at every 3 m distance. The results of the analysis show that the deflection that occurs between the girders after the installation of the diaphragm is uniform. The installation of diaphragms with a distance of 6.275 m and 3 m can increase the uniformity of the girder structure up to 8.12 times and 6.60 times respectively. Whereas the installation of diaphragms with a distance of 6.275 m and 3 m can increase the stiffness of the girder structure up to 10.96 times and 11.26 times, respectively. This shows that adding a diaphragm can provide rigidity and compactness between the girders.