An investigation of seismic behaviour of multi-span bridges on shallow foundations with soil-structure interaction methods


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: EKİN AKKAYA

Danışman: BAHADIR SADIK BAKIR

Özet:

During the design process of most of the bridge projects, the interaction between soil surrounding the foundation, and bridge-pier foundations is not accounted due to the complexity of application. Although it is accepted that disregarding the interaction results in reasonable and economical solutions that are on the safe side, this is not always the case. Since the ground supporting and surrounding the foundation is a deformable medium, displacements occur at the shallow foundations of bridge-piers. Also, foundations may uplift as a result. The purpose of this study is to investigate the structural behavior of the multispan bridges under seismic loads for different soil and structural stiffnesses to observe the effect of soil-structure interaction on the bridge response. It is concluded that soil and structural stiffness parameters influence the dynamic response of the structure. The sensitivity of the structure to the seismic excitation increases with decreasing soil stiffness. Calculated values of displacements revealed that displacement demand of the structure should be carefully examined with soil-structure interaction analysis. Contrary to the general belief, the fixed base approach does not always yield to the results which are on the safe side. Based on the analyses results, it is concluded that the consideration of soil-structure interaction is required for more precise and economical design for the seismic behavior under certain conditions.