Papers by Author: Qing Tian Su

Abstract: The concrete decks in wide box composite girder bridge carrying vehicle load directly are easy to failure. So the decks in approach bridge of Jiubao Bridge are designed to renewable component. Several deck removal plans were put forward based on the structure characteristics of the Jiubao bridge. Spatial finite element model of the bridge was set up and the responses of approach bridge under different removal plan were analyzed. The analysis results show that methods proposed in this paper about deck removal in local position or in whole span are feasible; however different whole span removal method affect the mechanical behavior of the approach bridge heavily.

Abstract: Based on the vehicle load model for fatigue design, the stress influence line of the reinforcement in the concrete slab of northern approach of Jiubao bridge, a multi-span continous composite bridge, under the global live load was obtained by spatial frame structure finite element model, while the stress history of the reinforcement under the local live load was obtained by the spatial refined finite element model. Then the stress spectrums under global and local live load were obtained by Rain-flow method according to the predicted traffic volume in the future 100 years and comparisons of amplitudes of equivalent stress under different loads were achieved. At last the fatigue lives of the slab under the different loads were calculated and compared either.

Abstract: Steel and concrete composite girder began to be used in arch bridge. For the existing of shear lag, the concrete deck in same cross section did not bear identical stress completely. No stipulations for effective width of concrete deck of composite beam in arch bridge are given in current design specifications and codes, which causes difficulties in analyzing the mechanical behavior of composite arch bridge by beam-column method. In this paper, the mechanics calculation for a multi-span arch bridge with continuous composite beam is conducted. Stresses distribution pattern of concrete deck in transverse direction and the variation of effective width of concrete in longitudinal direction are studied. The degree of impact of effective width caused by varying loads on structure and by varying some details on structure is discussed.