Performance Evaluation of Design Methods for Geosynthetic-Reinforced Pile-Supported Embankments

Abstract

Geosynthetic-reinforced pile-supported (GRPS) embankments are widely used in soft soil regions to support roadways. Various design methods for GRPS embankments have been developed; however, engineering experience and recent research have shown that the performance of these design methods varies case by case. This paper systematically evaluates the performance of several empirical GRPS embankment design methods, which include the BS8006 method, the Nordic method, the EBGEO method, the FHWA method, and the CUR226 method. A preliminary assessment of these methods using three field case studies confirms that their performances differ from each other and from field measurements, the differences sometimes being quite significant. To enable a more systematic evaluation of the design methods, a validated finite element model (FEM) was first used to conduct a comprehensive parametric study considering typical soft soil conditions and various geometrical parameters, the results of which served as a baseline for the evaluation of the design methods. The efficacy, stress concentration ratio, maximum differential settlement, and maximum reinforcement tension were used as indicators for the method evaluation. The results show that, overall, the CUR226 method outperforms other design methods. The percentage difference between the CUR226 method and FEM can be as small as 5%, and the maximum value is 130%. It was also found that the Nordic method does not apply to small embankment heights, and that the BS8006 method provides a large overestimation of reinforcement tension when pile spacing is large (>4 ft) for all embankment heights considered.

Analysis of Geosynthetic – Reinforced Stone Piles – Supported Embankments

“…To model the interaction behaviour between them, interface elements were used, which can be characterized by two parameter sets: between the geosynthetic and the granular pile and between the geosynthetic and the surrounding soft soil. The coefficient of sliding friction (μ) between the geosynthetic and the granular pile was chosen to be 0.5 (= 2/3 tan) [24][25][26], where the friction angle of the pile material to the interaction between the geosynthetic and the soft soil was assumed to be 0.3 (= 0.7 tan) [27][28], which is the friction angle of the soft soil. The parameters used in the numerical analyses are summarized in Table 1.…”

Effects of Topological Parameters on Thermal Properties of Carbon Nanotubes via Molecular Dynamics Simulation

“…Park et al's research shows that the concentration of vacancy defect (up to 2%) can reduce thermal conductivity by more than 80%. It must also be noted that Park's research focused on (6,6) SWNTs of varying lengths as opposed to (10,10) SWNTs in the study conducted by Chien et al The results show that the introduction of vacancies reduces the thermal conductivity to about 0.5 W/m•K. The main reason for the decrease in thermal conductivity is that the lack of bonds around the vacancies immediately terminates short-wavelength phonons.…”

“…The demand for polymeric composites has grown significantly due to the requirements of human communities and industries for the construction of lightweight, strong, and durable structures, as well as the need for highly conductive materials [1][2][3]. Among the various options for the reinforcement of polymeric matrix nanocomposites, carbon-based nanofillers, including carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs), could help to achieve the desired improvement in the thermal conductivity of the nanocomposites [4][5][6]. CNTs have special properties such as high strength, lightweight, unique electronic structure, and high stability, making them ideal materials for a wide range of applications.…”