竹巴龙金沙江大桥水毁破坏机理

为了研究竹巴龙金沙江大桥的破坏机理,基于泄洪实测数据,并考虑T梁底部横隔板腔室中裹挟空气的影响,建立了该桥1:20缩尺数值仿真模型,对洪水作用下简支T梁桥上部结构洪水作用力特征、流场特征和破坏机理开展了深入研究.?研究结果表明:当淹没率不超过1.342时,水平力系数随淹没率的增大而增大,当淹没率大于1.342时,水平力...

Failure Mechanism of Flood Damage to Jinsha River Bridge at Zhubalong

To explore the failure mechanism of Jinsha River Bridge at Zhubalong, a 1∶20 scaled numerical simulation model of the bridge was built with the measured field data in flood discharge, while the influence of air trapped in the diaphragm chamber at the bottom of T-beam is analyzed. The characteristics of flood force, flow field and failure mechanism of superstructure of the simply supported T-beam bridge under the effect of flood are studied in depth. Results show that when the submergence ratio is less than 1.342, the horizontal force coefficient increase with the ratio; when it is beyond 1.342, the coefficient decreases with the ratio. Before the backwater crosses the guardrail, the vertical force and overturning moment coefficient gradually increase with the submergence ratio. When it crosses the guardrail, the vertical force and overturning moment coefficient decrease sharply. When the submergence ratio is close to 1.000, the risk of the superstructure failure is the greatest. During the failure process of the bridge, horizontal movements occur first, and then there is a high probability that floating and overturning occur. The beam movement leads to the destruction of the link stopper, and part of the beam overturns in the falling. Solid railings contribute up to 31% of the horizontal force, and the contribution of entrapped air to the vertical force is up to 18%. Solid railings and entrapped air are important causes for flood damage or accelerating the bridge damage.