刚构-连续梁桥船撞桥墩最不利位置及安全性评价

The most unfavorable position of vessel-pier collision and safety evaluation for rigid frame-continuous beam bridge

以湘府路湘江大桥(65+5×120+65)m刚构-连续梁桥为工程背景,采用2种方法研究了桥墩在纵横向船舶撞击力作用下的墩身弯矩随船舶撞击高度的变化规律,以确定船撞桥墩的最不利位置。方法一采用简化计算模型进行桥墩弯矩公式推导,方法二采用Midas Civil建立空间有限元仿真全桥模型进行墩身弯矩计算。计算结果表明:有限元仿真全桥模型计算得出的墩身弯矩与简化计算模型推导出的结论是一致的,在船撞力作用下整个桥墩中墩底弯矩最大,且墩底弯矩随着船撞力作用点的升高而增大;简化计算模型中采用了若干简化处理,在进行桥梁船撞安全性评价时宜采用有限元仿真全桥模型计算。本文结果对桥墩设计与船撞安全评价具有一定的指导意义,并在此基础上对此刚构—连续梁桥船撞桥墩安全性进行了评价。

On the background of Xiangfu Road Bridge in Xiangjiang River, it is a rigid - continuous beam bridge which was used to decide the most unfavorable position of vessel - pier collision. Two methods was applied to in- vestigate the change law of pier moment with the variation of collision height under the condition of ship couision acting on the longitudinal and transverse position of pier. The first method was employed to derive the pier mo- ment formula with simplified calculation model and Mides civil coas applied to generale a dimisional finite ele- ment simulation total bridge model and compute the pier moment in the second method. The calculation results show that the pier moment derived from the finite element simulation full bridge model is consistent with the con- clusion derived from the simplified calculation model, and the moment of pier bottom is the maximum under the action of vessel collision, and it tends to increase with the vessel collision point rising. Owing to several simplify- ing presumptions were made in the simplified calculation model, the finite element simulation full bridge model had better be adopted to evaluate the vessel - pier collision safety. The results have some instructive significances for design and vessel - pier collision safety evaluation, and on the basis of which the vessel - pier collision safety evaluation for Xiangfu Road Bridge was conducted.