Field monitoring evaluation of geotextile-reinforced soil-retaining walls

Abstract

The use of geotextiles as reinforcement in soil-retaining walls may offer benefits over the use of other types of reinforcement, such as metallic strips or geogrids. These include ease of construction, expediency, and significant cost reduction. However, the lack of field monitoring results documenting the behavior of geotextile-reinforced structures, mainly regarding deformations, has precluded widespread utilization of these systems. A better understanding of the behavior of geotextile-reinforced soil structures could be gained by systematic monitoring of full-scale structures, combined with a thorough material characterization program. Accordingly, eight prototype geotextile-reinforced soil structures were built as part of a comprehensive study aimed at analyzing their behavior. This paper presents the characteristics of the prototype wall used as baseline for this series of structures, including construction details, instrumentation layout, and the results of laboratory tests conducted to characterize the soils and geosynthetics involved in this structure. The lateral displacements at the face of the wall were small, with increasing lateral displacements observed over time, particularly in association with precipitation events during the summer season in Brazil. The largest horizontal strains occurred towards the face, at mid-height of the prototype wall. The use of sigmoid curves to fit displacement results within the geotextiles was found to be very useful to define the value and the location of the peak strain in each reinforcement layer. The location of maximum reinforcement strains within each layer was found to be consistent with the development of a potential failure surface starting at the toe of the wall and propagating into the soil mass. The maximum reinforcement tension predicted using the K-stiffness method was found to compare well with reinforcement tension values obtained from monitoring results.