连续梁桥横桥向等位移准则

首先分析了单自由度等位移准则与结构屈服程度的关系，然后针对典型连续梁桥的特点，定义了名义屈服位移和名义屈服曲率，并通过改变主梁特性、桥墩特性和地震动输入等进行参数分析，将等位移准则由单自由度推广到多自由度。研究表明，当连续梁桥的主要振型的周期均大于对应单自由度等位移准则的周期下限，并且主要振型的质量参与系数之和超过90%时，非线性时程方法得到的位移与弹性反应谱方法得到的位移接近，等位移准则成立，可以采用弹性位移评估其非弹性位移。多自由度等位移准则的应用较大程度简化了相当一部分连续梁桥的横桥向位移需求的计算，为其基于位移的抗震设计提供了基础。

Equal transverse displacement criterion for continuous bridges

The relation between SDOF equal displacement criterion and yielding extent of structure was analyzed. The nominal yielding displacement and nominal yielding curvature were defined based on the traits of general continuous bridges. SDOF equal displacement criterion was then extended to MDOF on the basis of analyses on different kinds of continuous bridges with different girders, piers and earthquake inputs. The results show that the displacement calculated with inelastic time history method is close to that with elastic response spectrum method and the equal displacement criterion is applicable when the periods of structure's main modes are larger than the corresponding lower limit period of SDOF equal displacement criterion and the sum of main modes' participating mass factors is more than 90%, thus the elastic displacement can be used to evaluate the corresponding inelastic displacement. The application of MDOF equal displacement criterion simplifies the calculation of displacement in the transverse direction of a large number of continuous bridges and provides a basement for the displacement-based seismic design of those bridges.