Georeferenced monitoring of displacements of gabion walls

Abstract

Gravity retaining structures in gabion walls were built in the outdoor area of a shopping centre in the city of Manaus, State of Amazonas, Brazil. When the project was about half-way completed, horizontal displacements began to show excessive ‘bulging’, causing the stoppage of construction. Later studies revealed that the original geometric sections did not meet the requirements of internal, external and global geotechnical stability. Hence, it was necessary to study some alternatives to circumvent the problem. The fastest and most economical alternative proved to be increasing the cross-section of the walls, through the excavation of the backfill. The reconstruction of the walls and subsequent backfill compaction were performed step by step. The new cross-sections of the walls improved their theoretical and constructive stability, and this was proven by subsequent monitoring of horizontal and vertical displacements. It was found that the largest horizontal and vertical displacements of the gabion wall were about 20 mm and 11 mm, respectively.