Test Loading of Quay Structures using FEM

Abstract

Quay structures play an important role in society. How much load these structures can withstand however is not certain. This MSc thesis contains insight into the load capacity of the old Amazonehaven and the current SIF quay structures. Both are quay structures which use a combined sheet pile wall, a reinforced concrete relieving platform, M.V.-piles, and two rows of bearing piles. The objective of this MSc thesis was to determine the load capacity of the structures, the models should therefore be as close to the actual conditions as possible. For that reason no safety and/or material factors have been applied throughout this MSc thesis. The approach is shown below.
A literature study was performed to gain insight into the areas of interest that needed to be studied. This theory in combination with a review of the structures led to the critical cross sections of the respective structures. These cross sections were then modelled with conventional design methods (Blum and D-Sheet Piling). The Blum method determined the individual contributions of several aspects (loads, water, soil) to the horizontal stress distribution along the combined sheet pile wall and calculated the reaction forces using a set of boundary conditions. Within D-Sheet Piling the relieving platform was modelled by removing it, the loads that acted on it, and the soil that rested on it. The last method that was applied was a FEM software (Plaxis 2D). The FEM models were validated in three steps: First, by comparing their results to that of the conventional methods, it was found that the results of the conventional methods were within ca. 30% of the FEM results. Second, by comparing the results to actual field data, here the results showed both deviation and similarities, these deviations could however be explained. Lastly, by critically assessing the models to ensure that certain aspects were incorporated into the models correctly, this resulted in uncertainty about drained or undrained soil conditions for the thicker clay layers. The main function of both quay structures was the storage of certain goods, for that reason the only aspect that was not constant in the test loading set up was the magnitude of the primary surcharge. Both geotechnical and structural failure were taken into consideration for the quay structures.
The results of the FEM models showed that neither of the structures had failed at their design loading conditions. For the Amazonehaven it was found that the magnitude of the primary surcharge at the first failure of the model was relatively close to that of the design loading conditions, it was incited by the exceedance of the geotechnical bearing capacity of the M.V.-piles. The first failure of the SIF model occurred at a surcharge that was more than 4 times the magnitude of the design loading conditions, it was incited by the exceedance of the normal stress capacity of the M.V.-piles.