Using the new SAP2000 open application programming interface to develop an interactive front-end for the modal pushover analysis of bridges

Seismic assessment of bridge structures often requires inelastic (static or dynamic) analysis methods to be used, in order to draw a realistic evaluation of the structural behaviour beyond the elastic range. While the widely-used non-linear static (pushover) analysis provides a low-computational-cost approach to this direction, it is inherently limited by the assumption that the structure's response is solely controlled by its fundamental mode. This limitation is raised by an extension of the "standard" pushover analysis (SPA) to take into consideration the effect of higher modes , a method known as Modal Pushover Analysis (MPA). This method however, can often prove to be time-consuming and strenuous both for pre- and post processing. The latter, provided the motivation for investigating the feasibility to take advantage of the recently released SAP2000 application programming interface (API) in order to develop a new computational tool that implements the MPA specifications for evaluating the seismic behavior of bridges in an organized and automatic fashion. The paper concludes with the application and demonstration of the software developed, for the case of an existing reinforced concrete bridge located along the Egnatia Highway in Greece.