A Method For Improving The Capacity Of Bridge Girder At Intersection By Maintaining The Height Clearance

Abstract

RAPid development of transportation must be in line with the enhancement of infrastructures capacity including the bridge capacity and serviceability. The capacity and serviceability of the bridge can be done by enhancing the main girder. The current method to improve the girder capacity is to increase the moment of inertia of the cross section by mean increasing the height. However, this method will reduce the height clearance under the bridge. This disadvantage can be resolved by modification of the girder section. This paper presents a method to improve the capacity of girder by modification the cross section. Two plate girder section, named double delta model, was used in this research to increase the girder capacity to support the applied load and moment capacity without increasing the height of the girder. The model was modified cross section of the I-beam. The research results showed that the modified plate girder can applied to improve the girder capacity and maintenance the height clearance. The double delta model with size ratio of the web and flange 4.6 and 5.29 was able to support load about 2.65 of the I-beam section. In addition, the maximum moment can be increased to 2.21 and 2.5 respectively. The model needs additional steel plate about 1.48 to 1.52 of the original girder.