风浪荷载共同作用下大跨度刚构桥动力响应规律研究  

Study on Dynamic Response Rule of Long-span Rigid Frame Bridge Subjected to Coupled Actions of Wind and Wave Loads

作　　者：罗浩[1] 吕海龙[1] 谢献忠[1] 汪建群[1] 郭辉[2] LUO Hao;Lü Hai-long;XIE Xian-zhong;WANG Jian-qun;GUO Hui(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan Hunan 411201,China;Railway Engineering Research Institute,China Academy of Railway Sciences,Beijing 100081,China)

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201 [2]中国铁道科学研究院铁道建筑研究所,北京100081

出　　处：《公路交通科技》2019年第8期78-85,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51408217,51408218,51608193);湖南省自然科学基金项目(2015JJ3066);湖南省教育厅一般项目(16C0645)

摘　　要：风浪作用在结构上会对结构产生动力作用,从而影响到结构的内力及响应。为研究风浪作用下大跨度连续刚构桥的动力响应规律,利用通用有限元软件ANSYS建立了刚构桥的有限元模型,并以经典理论为基础,在风浪耦合关系的基础上建立了风场和波浪场的数值模型,此数值模型在抖振力响应的基础上考虑了波浪对风场的影响。对大跨度刚构桥在风浪荷载共同作用下的动力响应结果进行了分析。研究结果发现:对比风荷载、波浪荷载单独作用及风浪荷载共同作用下桥梁不同位置的横向位移响应结果,墩顶位移相对增幅要大于跨中位移相对增幅,波浪荷载作用对桥梁横向位移响应的影响从桥墩到跨中依次减小;对比风荷载、波浪荷载及风浪荷载共同作用下桥梁墩底剪力及墩底弯矩响应结果,波浪荷载作用对墩底横向剪力、墩底纵向剪力、墩底绕横桥向弯矩和绕纵桥向弯矩均有明显影响,波浪荷载作用对墩底剪力的影响很大,对墩底弯矩的影响较大;风浪荷载共同作用并不是风荷载、波浪荷载单独作用下响应的简单叠加,波浪形成时会对风场产生影响,除了随机湍流风速以外,波浪会引起与波浪同步的上方气流速度变化,在风浪场中的风速模拟时,需要考虑波浪对上部气流的影响,因此对横向位移响应影响较大的主要作用为风荷载作用,但并不意味着可以忽略波浪荷载的作用。Wind wave action on the structure will have a dynamic effect on the structure, thus affecting the internal force and response of the structure. In order to study the dynamic response rule of long-span continuous rigid frame bridges under wind and wave loads, the FE model of rigid frame bridge is established by using the general FE software ANSYS. Based on the classical theory, the numerical model of wind and wave fields is established on the basis of wind-wave coupling relationship. This numerical model considers the influence of waves on wind field on the basis of buffeting force response. The dynamic response of long-span rigid frame bridge under the combined action of wind and wave loads is analysed. The result shows that (1) Comparing with the results of the transverse displacement responses of bridge at different positions under the wind load, wave load, and combined action of wind and wave loads, the relative increment of pier top displacement is larger than that of mid-span displacement. The influence of wave loads on the lateral displacement response of bridge decreases from pier to mid-span in turn.(2) Comparing with the results of shear forces and excavation response at pier bottom under the wind load, wave load, and combined action of wind and wave loads, wave load has obvious influence on transverse and longitudinal shear forces at pier bottom, and transverse bending moment and longitudinal bending moment around pier bottom.(3) The interaction of wind and wave loads is not a simple superposition of the responses under the action of wind and wave loads alone. When waves form, they will affect the wind field. Besides the random turbulent wind speed, the wave will cause the fluctuation of the upper airflow velocity synchronized with the wave. When simulating the wind speed in the wind and wave field, we should consider the influence of waves on the upper airflow.(4) The main influence on the lateral displacement response is the wind load, but it does not mean that the influence of waves can be ignored.

关 键 词：桥梁工程 风浪耦合 数值模拟 刚构桥 动力响应 

分 类 号：U448.23[建筑科学—桥梁与隧道工程]