Measured Performance and Stability Analysis of Large-Scale Reinforced Model Embankments at Different Moisture Contents

Abstract

This paper describes construction and instrumentation of two 1.65-m high reinforced embankment models that were tested at two different gravitational water contents (GWC) on the dry and wet sides of the optimum moisture content (OMC); i.e. OMC-2 % and OMC?2 %. The embankment models were constructed using a clayey sand that was reinforced with four layers of instrumented geotextile with a uniform vertical spacing of 300 mm. Each model embankment was subjected to a line surcharge load (strip footing) near its crest until failure. The magnitudes of GWC, earth pressure, geotextile strains, footing settlement and embankment deformations were measured using EC-5 sensors, earth pressure cells, wire potentiometers, linear variable deferential transformers and reference plates, respectively during the construction and loading phases of each test. The GWC values in each model embankment were measured using EC-5 sensors and the oven drying method to ensure that they were close to the target values. Slope stability analysis was carried out to study the equilibrium of embankment models and to validate the predicted bearing capacity and factor of safety results against the experimental data. Results of this study show that the embankment model constructed on the dry side of OMC (i.e. OMC-2 %) had a 10 % greater serviceability failure load than the model built at OMC?2 %. Meanwhile, stability analysis results indicate that the bearing capacity of an unreinforced model embankment at OMC-2 % would be 72 % lower than that of the corresponding reinforced model. It is also found that compaction-induced energy could increase the earth pressure within the embankment by up to 70 % of the vertical stress in the soil mass due to gravity.

Case Study on Field Observation of Reinforced Embankment in Snowy Cold Region

“…Figure 4 was taken when creating strain gauges attached to the geotextiles laid in the reinforced embankment and when setting them up in the reinforced embankment. There are several reports on cases of measurement of the strain acting on reinforcements that use geosynthetics [3,4]. The reinforced embankment discussed in this paper employs ultrahigh-strength polyester fibres, and there are few reports on the measurement of the strain in such a case.…”

“…Similar considerations are believed to be applicable not only to reinforced soil walls but also to reinforced embankments. The results of field observations for reinforced embankments have been reported [1][2][3][4]. From this result, data have been accumulated on the strain and soil moisture of the reinforced embankments with large height.…”

Road Embankment Full-Scale Investigation on Soft Soil With Geotextile Stabilization

“…To handle the problem, the soil will be strengthened at first before any construction work is done. One of the ways is to use geosynthetic materials for soil stabilization at the base of the embankment [3][4][5][6][7]. The stabilization will not occur only at the base since a few layers of geotextile can be added [8].…”

“…However, there is no data on broad field supervising on the said embankment. It is necessary to consider using local materials as much as possible and not using selected material that is transported outside of the road construction site [5].…”

Large-Scale Prototype Testing of a Composite Geosynthetics Reinforced Earth Structure for Riverbank Slope Protection Using Fine Grained Sandy Soil

“…Moreover, as for the large scale field test, most studies have conducted a pullout test performance of the geosynthetics to evaluate the shear resistance of the soil-geosynthetics on field. Also, actual instrumentations of field models were performed where wall deformations and reinforcement strains of the reinforced structures were determined (Abu-Farsakh et al, 2006;Benjamin et al, 2007;Ferreira et al, 2015;Esmaili and Hatami, 2015). Nonetheless, traditional orientation of the reinforcement and wall facing blocks are still frequently used.…”