钢箱梁自行车桥的舒适度研究

Study on comfort of bicycle bridge with steel box girder

为研究厦门市薄壁弯箱梁自行车桥的舒适度,借助SAP2000有限元软件建立自行车高架桥三维模型,参考德国标准EN 03设计人行荷载模型,计算0~50Hz频率范围内桥梁的动态响应,根据该桥结构动力特性,分析0~4Hz激励荷载作用下各跨跨中的动力响应及不同桥跨之间的衰减情况。结果表明:激励响应主要以竖向响应为主,横桥向和顺桥向的位移值大约为竖向位移值的0.51%~27.69%;第4跨激励响应最大,第3跨最小;相邻跨受迫振动响应随跨度距离的增大依次减小;跨内及不同桥跨间的加速度响应结果均达到规范规定的舒适度要求;速度响应同加速度在趋势上吻合度良好,速度指标可作为舒适度评价补充验算的指标。该研究结果对今后指导自行车桥设计和舒适度分析意义重大,并为研究者对该类桥的进一步研究提供借鉴。

In order to study the comfort degree of Xiamen thin-walled curved box girder bicycle bridge,a three-dimensional model of bicycle viaduct is established using the finite element software SAP2000.Referring to German standard EN 03,a pedestrian load model is designed to calculate the dynamic response of the bridge in the frequency range of 0~50Hz.According to the dynamic characteristics of the bridge structure,the dynamic response of each span under 0~4Hz excitation load and the attenuation between different spans are analyzed.The results show that the excitation response is mainly vertical,and the transverse and longitudinal bridge displacements are about 0.51%~27.69%of the vertical displacements.The fourth spanpresent the largest excitation response,while the third span the smallest.The forced vibration response of the adjacent span decreases with the increase of the span distance.The acceleration responsesboth within the span and between the different spans meet the comfort requirements specified in the code.The speed responses exhibit the similar trend to the acceleration responses,and velocity can be used as a supplementary check index for the comfort evaluation.The research results of this paper are of great significance to guide the design and comfort analysis of bicycle bridges in the future,and provide reference for researchers to further study such bridges.