自锚悬索桥塔梁地震响应4参数估算法

Parameter Estimation of the Four Parameters for Tower and Girder Seismic Responses of Self-anchored Suspension Bridge

基于弹性概念,提出了自锚式悬索桥塔、梁地震响应4参数估算法。该方法通过自锚式悬索桥静力分析和自身结构参数,查找对应图表中系数,对方案设计和初步设计阶段结构地震响应给出估算。所查找的图表基于《公路工程抗震设计规范》规定的7度地震区(8度设防)、Ⅱ类场地土,根据已有和在建的自锚式悬索桥资料建立分析模型,考虑几何刚度影响,利用恒载作用下平衡状态,输入3条地震波,且为了对比还进行了反应谱分析,得出相关图表。最后应用4参数法通过实桥算例与有限元分析结果进行对比,结果说明了该方法可以应用于自锚式悬索桥方案设计和初步设计阶段的塔、梁地震响应估算。

Four-parameter method for estimating the seismic responses of self-anchored suspension bridges is presented based on elastic concept. The method gives factors obtained from static analysis of self-anchored suspension bridges and their structure parameters, which can estimate the seismic responses for plan design or primary design. The corresponding table and figure are based on state 7 degree earthquake intensity region （8 degree seismic fortification intensity） and Ⅱ style ground specified in Design Specification of Highway Engineering for Earthquake Resistance. Then models of bridges abuilding or having been constructed are established. Considering the effect of geometric stiffness and dead load, dynamic balance equations are derived, and tables and figures are given for three earthquake waves. The method can be applied to the estimarion of seismic responses for self-anchored suspension bridges in plan design or primary design by comparing the seismic response results by this method and by the finite element analysis of a real bridge.