Seismic structure-soil-structure interaction between two different adjacent piled bridges founded in nonlinear soil

Abstract

ABSTRACT This paper evaluates the influence of structure-soil-structure interaction (SSSI) on the seismic behaviour of two adjacent bridges with different superstructure masses. The bridges are supported by groups of piles implanted in nonlinear clay. A thorough detailed parametric numerical analysis has been carried focusing on the effect of the superstructure mass ratios (200%, and 300%), inter-bridge spacing, and the position the two bridges towards each other and towards the seismic loading direction. An extensive series of numerical analyses have been carried out using a full three-dimensional finite-difference FLAC software. The responses of adjacent bridges have changed remarkably due to (SSSI) effect. The results showed a significant positive effect of the superstructure mass ratio of (300%) by a considerable drop of acceleration up to (96.39%) and a notable reduction of the internal forces of the grand bridge piles up to (75.9%). This implies the properly planned configurations of adjacent structures and attentive selection of their properties could be employed efficiently to control the effects of structure–soil–structure interaction, whereas inter-bridge spacing has a rather slight effect on the superstructure acceleration and the pile’s internal forces. In contrast, the positioning of the bridges has revealed a sensible influence on their seismic behaviour.