Case Study of Barrette Retaining Wall, Kent, UK

This paper presents a case history of a retaining wall designed by Arup and constructed in Kent, UK, between 1996 and 1998, as part of a highway cutting. The design methodology which was applied for this novel wall type is introduced, and measured horizontal displacements are presented and discussed. The design requirements specified that the wall had to be capable of supporting up to 8.8 m of retained height and was not to be propped or anchored. To attain sufficient bending stiffness, Arup introduced a series of discrete barrettes perpendicular to the excavation. Arches of sprayed concrete retain the soil between the barrettes above dredge level. The barrettes were designed applying the general design principles for embedded retaining walls. Pore water pressures on the wall were reduced and controlled by installing a back of wall drainage system. Inclinometers in one of the instrumented wall sections were recently re-read. These data are shown and compared to the original predictions. Overall the wall showed only minor movements and satisfies the stated design requirements.