Skip to content

Reinforced soil shear key to mitigate extrusion failure in soft soils under working platforms

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Geogrids and geotextiles are widely used in working platforms to increase the allowable surface bearing pressures and reduce the platform thickness required. While analytically based approaches exist for the design of these platforms, these vary in their complexity and the range of critical properties they consider, leading to uncertainty in which ones to suggest. They can be over conservative compared to empirical methods based on historical performance. For projects with combinations of high rig loading and very soft underlying ground (cu < 20 kN/m2), there is greater potential for extrusion and edge circular failures. The edge stability of platforms can be improved with a number of measures such as increased stand-off zones, loading mats, balancing mounds and shear trenches. This paper considers the extrusion mechanism and how a wrapped shear trench can be used to counteract edge insta-bility and extend the suitability of platforms over very soft soils. The effectiveness of this method is demonstrated with a UK case study. This paper covers a brief introduction to working platform design, before comparing a range of approaches. The paper discusses the extrusion failure mechanism and a solution using a wrapped shear key trench.
Original languageEnglish
Title of host publicationProceedings of the XVII ECSMGE-2019
PublisherInternational Society for Soil Mechanics and Geotechnical Engineering
Number of pages8
ISBN (Print)978-9935-9436-1-3
Publication statusPublished - 1 Sep 2019
EventThe XVII European Conference on Soil Mechanics and Geotechnical Engineering Reykjavik Iceland - Reykjavik , Iceland
Duration: 1 Sep 20196 Sep 2019


ConferenceThe XVII European Conference on Soil Mechanics and Geotechnical Engineering Reykjavik Iceland
Abbreviated titleXVII ECSMGE-2019
Internet address


  • 1020-ECSMGE-2019_Scotland

    Rights statement: Ian Scotland, Viktor Poberezhniy & Alireza Tatari. 'Reinforced Soil Shear Key to Mitigate Extrusion Failure in Soft Soils under Working Platforms'. Proceedings of the XVII ECSMGE-2019. © 2019 The authors and IGS: All rights reserved.

    Final published version, 589 KB, PDF document

Related information

Relations Get citation (various referencing formats)

ID: 15710685