STATE-OF-THE-ART OF RESEARCH ON SEISMIC INCIDENT DIRECTIONALITY EFFECT OF CIVIL ENGINEERING STRUCTURES

Multi-dimensional ground motion has a high degree of uncertainty on the incident direction of civil engineering structures, and the structure designed upon the traditional method without considering the incident directionality is prone to incident directional seismic damage in earthquakes. How to ensure the seismic safety of structures in an arbitrary direction of incidence is a problem that scholars at home and abroad are very concerned with. A variety of ground motion prediction models are proposed and applied to specifications using ground motion intensity measures considering the incident directionality. The reliability of the measures in the specifications is low and some adjustments need to be made. Moreover, the directionality effect of seismic incidence has been widely studied in the fields of building structures, bridge structures and some special structures, and the results show that the effect of incident direction is significant and have certain reference significances for structural seismic design, but there are still some shortcomings. In order to improve the seismic design method, a variety of methods solving most unfavorable direction of incidence are proposed, but their applicability is low, and it is an effective measure to use statistical methods to investigate the uncertainty of incident direction. In the future, it is necessary to promote its application to different civil engineering structures to optimize seismic design methods. In addition, four joint probability seismic fragility models with ground motion intensity and incident direction as random variables are developed, and the seismic risk of various civil engineering structures is evaluated. However, their analysis efficiency is low and needs to be improved to achieve rapid structural risk assessment. At present, the relevant researchers mainly focus on using numerical methods to study some phenomena. In the future, theoretical and experimental techniques should be used to achieve breakthroughs from phenomena to mechanisms and theories, and finally engineering applications should be carried out to create conditions for improving seismic specifications.