Long bridges and other lifeline systems are particularly susceptible to the spatial variability of earthquake actions. Even though it is a matter that has been substantially studied in the past decades, there are still plenty of issues with the engineering application of earthquake spatial variability. One of the difficulties is generating displacement time-histories with zero initial and small residual displacement values. This is essential to obtain results that have good quality in terms of the pseudo-static effects. Another difficulty is the uncertainty associated with the simulation of the spatial variability of the seismic ground motions in engineering applications (Zerva et al. in: 16th European conference on earthquake engineering, Thessaloniki, 2018). In this study, the conditional method for simulation of spatially variable ground motions is used and the respective displacement time-histories are generated. These time-histories are then applied to perform seismic analysis of a set of long irregular RC bridges, with different irregularity layouts and different total lengths. The goal of this study is to ascertain the impact of spatial variability on the seismic behaviour of these structures, according to their length, irregularity and to the coherency model of the strong motions and comparing the results with the case without spatial variability. The relative importance between dynamic and pseudo-static effects is also ascertained for each case-study. Finally, the definition of the cases for whom the effects of the spatially variable seismic ground motions are more detrimental than those of the uniform ground motions.

长桥和其他生命线系统特别容易受到地震作用的空间变化的影响。尽管在过去的几十年中已经对该问题进行了实质性的研究，但是地震空间变异性的工程应用仍然存在很多问题。困难之一是生成初始时间为零且残余位移值较小的位移时程。这对于获得在伪静态效应方面具有良好质量的结果至关重要。另一个困难是与工程应用中地震地震动的空间变异性模拟相关的不确定性（Zerva等人在第16届欧洲地震工程会议上，塞萨洛尼基，2018年）。在这个研究中，使用了模拟空间可变地面运动的条件方法，并生成了各自的位移时程。然后将这些时间历史应用于对一组具有不同不规则布局和不同总长度的长不规则RC桥进行地震分析。这项研究的目的是根据空间的长度，不规则性以及强运动的相干模型，确定空间变异性对这些结构的地震行为的影响，并将结果与​​没有空间变异性的情况进行比较。还为每个案例研究确定了动态和伪静态效果之间的相对重要性。最后，