Soil-structure interaction and motion incoherency effects on a concrete bridge with deep foundations

Abstract

The paper presents a seismic SSI study that has been conducted for a 242 m long concrete bridge in Braşov, that has deep foundations on drilled piles. The structure is typical for Romania and highly used throughout the country. The seismic soil-structure interaction were performed using the state-of-the-art ACS SASSI software. The soil-structure interaction analyses were performed for both coherent (synchronous) and incoherent (non-synchronous) seismic inputs. The main focus of the study is to evaluate the effects of soil – structure interaction and of the seismic motion incoherency on the bridge dynamic response. The paper includes comparisons of results obtained using the Eurocode 8 analysis procedures and the state-of-the-art seismic soil-structure interaction analysis using ACS SASSI. The final conclusions indicate the limitations of the current bridge design soil-structure interaction modelling and the simplified motion spatial variability modelling in Eurocode 8. Furthermore, the future directions of the research study are presented.