Effect of Cap Geometry on Behavior of Steel I-girders to Inverted-T Bent Cap

Recently, a new steel girder bridge has been proposed to increase the space under the bridge and to improve aesthetic aspect of the urban area by connecting bent cap and steel girders. The core technology of the proposed bridge entails the introduction of prestressing force to steel girders and inverted-T bent cap by means of high-strength steel bars. This study investigates the effect of cap geometry on the behavior of the propsed bridge consisting of steel I-girders to inverted-t bent cap. Various geometries includes the change of width and height of bent cap. And this study is to ensure the structural safety of the proposed bridge system considering construction stages by means of 3-D finite element analysis. In each construction stage, stress states can be abruptly changed before each component of the proposed bridge works as a system. Variation of stress components for bent cap and girder were given with detail. It has been found that the height of inverted-T bent cap more sensitive factor to the behavior of the proposed bridge than width of bent cap. And analysis showed that sequential 3-D numerical analysis should be performed to ensure structural safety at each construction stage of the proposed bridge.