Investigation of earthquake behavior of box culverts considering soil-structure interaction

There are very limited studies on the evaluation of the earthquake behavior of partially or fully buried box culvert structures considering soil-structure interaction in the literature. The main purpose of this study is to propose numerical and analytical models for the analysis of soil-box culvert interaction systems by using the approaches that can consider the backfill and subsoil interactions in literature, and to demonstrate the usability of these models. Furthermore, it is aimed to investigate the effects of soil-structure interaction, earthquake frequency content, culvert wall thickness and backfill-culvert interface behavior on the dynamic responses of the box culverts through parametric analyses to be carried out by considering different earthquake ground motions and soil properties. It is also aimed to investigate the effects of soil-structure interaction and earthquake frequency content on the dynamic responses of the culvert wing wall. In line with the purposes stated, three-dimensional finite element models that can take into account the soil-culvert interaction and analytical models based on the substructure approach have been proposed within the scope of this thesis. In the recommended models, the mode frequencies of the interaction system were obtained using modal analysis technique for different soil conditions, and were presented comparatively. After showing the effectiveness of numerical models, the detailed dynamic analyses were performed in the time domain through these models considering different soil conditions and earthquake records. The obtained results reveal that the proposed numerical and analytical models can be used in the analysis of soil-culvert interaction problems. They also show that the dynamic behavior of the box culvert can be significantly affected by the factors such as soil-structure interaction, earthquake frequency content, interface assumption and culvert wall thickness variation.