Laboratory performance of reduced-scale reinforced embankments at different moisture contents

The paper describes instrumentation, testing, and detailed results of three 1-m high reinforced embankment models that were built in the laboratory at three different gravitational water contents (GWC). Each embankment model was subjected to a strip load near its crest until failure. The embankment models were constructed using lean clay at the GWC values ranging between OMC-2% and OMC+2% (OMC: optimum moisture content). Each embankment model included a single reinforcement layer which was placed 180 mm below the embankment surface. The location of the reinforcement layer was selected based on preliminary embankment tests and numerical simulations to ensure that it would intercept the failure surface that developed underneath the strip footing near the embankment slope. The embankments were instrumented with a total of 67 sensors to measure the soil GWC, matric suction and excess pore pressure, reinforcement strains, earth pressure and deformations of the embankment models, and the test box during the tests. The test setup and data described in this paper are part of a long-term study to validate a set of moisture reduction factors (MRF) introduced by the authors in their recent studies which involved pullout and interface shear tests on the same soil and reinforcement materials. Specifically, the data and discussions in this paper provide a basis for further in-depth analysis to verify or modify the authors' proposed MRF values for actual embankment configurations. Furthermore, the test descriptions and results in this study will be used to validate numerical models to examine the influence of the soil matric suction and moisture content on the soil-geotextile reinforcement interface strength and internal stability of reinforced soil structures. The ultimate goal of the study is to develop a better understanding of the influence of matric suction on the performance of reinforced earthen structures constructed with marginal soils, and improved methodologies for their design.