Sliding Resistance of Serrated-Base Quay Walls

A Master of Science thesis in Civil Engineering by Maryam Omran Jaroor entitled, “Sliding Resistance of Serrated-Base Quay Walls”, submitted in November 2021. Thesis advisor is Dr. Magdi El-Emam. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).

Abstract

Waterfront retaining structures, such as quay walls, play important roles in the safety and operation of ports and harbours. Designing waterfront structures under critical loads and conditions is one of the important topics of geotechnical research and coastal engineering. Block type gravity quay walls are the mostly used type, which consists of massive concrete blocks stacked on top of each other and setting on a foundation layer of gravel or crushed stone. While extensive studies are conducted on quay wall design, both numerically and experimentally, there is a gap on the design criteria adopted of serrated bases quay wall. The current design standard assumes a coefficient of friction µ=tan(soil friction angle) for serrated base wall instead of µ=tan(soil friction angle/2) in case of non-serrated base. This assumption is not supported by neither theoretical nor experimental analysis. Therefore, adopting this assumption for walls with serrated base might lead to a conservative or unsafe stability analysis of quay walls. The current research work attempts to tackle this gap, through analytical analysis and numerical modelling. The main objective of this research is to study and analyse the behaviour of concrete block type quay wall with different base configurations (serrated vs. non-serrated). To achieve this purpose, analytical and numerical models have been developed to investigate the sensitivity of the normalized equivalent base friction angle to different serration design parameters. The analytical model is driven based on the Coulomb’s passive earth pressure theory for cohesionless soil. However, the numerical model is developed using PLAXIS commercial software. The numerical and analytical models was used to conduct parametric study to investigate the effect of different variables such as serration height, number, and inclination, on quay wall sliding resistance. A combination of analytical and numerical results indicates that the design values of serrated base friction, used currently, are highly conservative. In addition, the sliding resistance of serrated-base quay walls can be significantly improved by using specific combination of serration design parameters (height, angle and number per meter). Results of this research is useful for design codes, municipalities and other agencies dealing with gravity type blocks quay walls.