平行双箱梁桥面颤振稳定性试验研究

在建的佛山平胜大桥和设计中的青岛海湾桥红岛航道桥方案分别是具有平行双箱梁的独塔自锚式悬索桥和独塔斜拉桥，对两座桥梁的单、双桥面弹性悬挂节段模型风洞试验结果表明双桥面之间存在不可忽略的气动干扰效应，从而使桥梁在单、双桥面状态时的颤振临界风速不同。以平胜桥主梁节段模型为基础的一系列风洞试验研究表明，平行双箱梁桥面主梁的颤振临界风速与两桥面之间的距离有关系，双桥面的颤振临界风速随两桥面之间距离D值的增大而增加。与单桥面状态相比较，平行双箱梁桥面的颤振导数也有相应的变化，且这种变化和两桥面之间的距离D也有关系。

Experimental Study on Flutter Stability of Parallel Box-Girder Bridges

Based on two of cable supported bridegs with parallel box girder,a serial of wind tunnel tests of their sectional models are performed to study flutter stability.In the tests,two sectional models are all supported with 8 springs in wind tunnel to consider aerodynamic interference between two decks of two bridges.The test results show that a bridge has different critical flutter speeds for its configurations of single deck and two decks.One of the bridge models is selected to study effect of distance between two decks on flutter stability.The test results indicate the critical flutter speeds of two decks configuration rise up with increase in D/B(D:distance between two box girders B:width of one deck).Compared with single deck,flutter derivatives of two parallel decks are modified and the modification is related to the ratio of D/B.The study shows that the aerodynamic interference between two decks cannot be ignored and the interference will affect flutter stability in a wide range of D/B.