OPTIMIZING THE DRAFT OF A QUAY WALL TO THE ANCHOR LENGTH RATIO USING FINITE ELEMENT NUMERICAL MODEL

Abstract

This research studied the effect of varying the distance between the front wall and the back anchor of a quay wall located in Abu Qir, Alexandria, Egypt. The quay wall was built to serve as a multipurpose terminal, the front wall is a combined wall system (tubular steel pipes connected by intermediate sheet piles) and the back (deep) anchor is a barrette pile. Researchers often study quay wall optimization and how various structural and operational changes could affect an existing quay wall’ s performance. However, the relation between a quay wall’s draft and the back anchor length using pile anchors was not studied previously. The added value of this research is providing several ratios between the quay wall draft and the back anchor length. The analysis was performed by varying the distance of the barrette piles, bringing them closer to and further apart from the front wall to conclude how this variation affects the quay wall elements. The numerical model was calibrated and verified using previous numerical models in two separate locations with different structure systems prior to conducting this research. The analysis was performed by conducting a three-dimensional numerical model using PLAXIS 3D V21 which is a finite element analysis software that models soil/structure interface. The results revealed that as the distance between the front wall and the back anchor increases, the moment increases on the combined wall while decreasing on the barrette, meanwhile, the front wall deflection decreases. The decrease in deflection is limited by the at rest and active plane of failures. It was concluded that the decrease in the front wall’s deflection becomes minimal after a draft to anchor length (d/L) ratio of 0.71 and the effect varying the d/L ratio has an immensely greater effect on the back anchor than on the front wall.