GEOWALL® as a Quay wall

Abstract

Bank protections are currently constructed with stone, wood, concrete and steel. NETICS has introduced a sustainable and commercially very attractive alternative called the GEOWALL. The goal of this study is to find a viable field of application within the quay structures by considering the arising challenges of a larger scale wall. Additionally several potential design improvements are described to cope with the challenges. The GEOWALL could fail due to sliding, overturning, exceeding internal stresses, large deformations, vertical instability, overall instability and piping. The safety of the structure will be assessed with predefined general factors of safety and permissible internal stresses, these are the test values. The safety for sliding, overturning, large deformations, vertical stability and piping is calculated with an analytical method. The safety for overall stability, internal strength and large deformations is calculated with a finite element method. There are two main variables in the analyses: the retaining height and the type of soil. The retaining height varies between one and five metres. The soils are simplified to sand, clay and peat. From the results of the analytical analysis and the finite element analysis it can be concluded that sand-GEOWALLs on sand between one and three metres and clay-GEOWALLs on clay between one and three metres are the most viable scenarios for a larger scale GEOWALL with current design. For GEOWALL quay walls larger than three metres and peat-GEOWALLs on peat suitable design improvements are required to meet the stringent safety requirements. The design improvements should be able to limit the possibility of failure due to sliding, overturning and failure trough large deformations. There are three categories of potential improvements: material improvements, geometrical design improvements and structural design improvements. The embedded wall is expected to be the most promising geometrical design improvement. Adding a drainage system is expected to be the most promising structural design improvement at this moment. It is recommended to study the effects and efficiency of the proposed design improvements in future research. It is also recommended for NETICS to continue their research on the strength and resistance of different GEOWALL types and on the influence of every possible load. In case of a GEOWALL design for a specific location it is recommended to determine the safety factors for that specific location and to check the analytical results with more advanced modelling programmes. Lastly it is recommended to consider not only the technical aspects, but also the practical and commercial aspects if one is investigating the design improvements.