Geosynthetic-reinforced pile-supported (GRPS) embankments are an attractive soft soil improvement technique. They are broadly used in infrastructure projects. Most previous studies focused on investigating reinforced piled embankments under static loading. There is a paucity of studies on structure behavior under cyclic loading. In the study, three-dimensional numerical modeling using the finite element method (FEM) was performed with the objective of better understanding the cyclic behavior of GRPS embankments in terms of load transfer mechanisms and settlements. An advanced constitutive model based on the hypoplasticity concept was employed for the embankment fill to simulate the cumulative strain during each loading cycle. Parametric studies related to the embankment height, traffic loading parameters (amplitude and frequency), and number of geosynthetic reinforcement layers are presented. The numerical results obtained indicate that the presence of a geosynthetic reinforcement decelerates the reduction in the arching effect within the embankment fill and decreases the cumulative settlements. The rate of the cumulative settlements decreases with the number of load cycles. The number of geosynthetic reinforcement layers does not appear to influence the soil arching and cumulative settlements.

With the current tendency to gradually increase the contribution of renewable energy to achieve significant proportions of the entire production, the wind farm construction rate is actually high. Because the location of the wind turbines (WTs) is dictated by factors usually independent of the foundation soil conditions, which are mostly based on energy production and consumption efficiency (e.g., average wind speeds, possibility of connecting to existing electrical networks, approval of authorities and local population, etc.), it is not uncommon for the construction sites to be unfavorable in terms of geotechnical demands. In these circumstances, the choice of the optimal foundation system is an important aspect in the design phase of a WT. The aim of this paper is to analyze, using three-dimensional (3D) numerical models and the suitability of currently available foundation solutions (based on a shallow foundation on the natural or improved ground), and compare the overall behavior with solutions based on rigid inclusions (RIs). The parametric study developed was based on a real soil profile, and all the foundation solutions are analyzed for realistic static WT loads. The assessment of the efficiency of each foundation system, as well as the subsequent comparative analysis, was performed in terms of the surface settlement on the foundation soil and the axial force and bending moment on the vertical reinforcements.

The aim of this study is to investigate the behavior of a footing lying directly upon a rigid inclusion-reinforced soft soil. Both experimental and numerical approaches were conducted. The studied cases include single rigid inclusion tests, a footing over nonrigid inclusion-reinforced soil, and a footing over rigid inclusion-reinforced soil. The vertical loading tests on single rigid inclusions and the footing over unreinforced soil showed the behavior of the multi-layered soil, thus allowing for the determination of soil parameters for the numerical analyses. The tests on the footing over reinforced soil were, furthermore, carried out with different loading cases (centered and eccentric vertical loads and horizontal loads). Special attention was paid to the influence of the complex loading cases on the footing over a reinforced soil system by the measurement of the inclusion head pressure, the vertical and lateral footing settlements, and the lateral inclusion displacements. The measured pressure on the inclusion seemed to increase linearly with the vertical loading on the footing. A good agreement between the numerical analysis results and measurement data has been found for the loading phases while underprediction appears for a few loading cycles, probably due to the simplified soil constitutive model adopted.

This paper is based on small-scale laboratory tests (1:10) of a rigid inclusion-improved soil under normal gravity. A low area improvement ratio (2.4%) under monotonic and cyclic loading was used. 3D numerical calculations are performed to model these tests. The proposed numerical modeling is performed by the finite element method (FEM) using the ABAQUS software. A representative elementary volume model is suggested for reducing the calculation time. A hypoplastic constitutive model (HYP model) is applied for the load transfer platform (LTP). A total of three geometrical configuration cases of the experimental tests are numerically considered including a rigid slab over a mattress of 100 mm on the reinforced soil, a mattress of 100 mm on the reinforced soil, and a rigid slab over a mattress of 50 mm on the reinforced soil. The proposed numerical results are compared to the experimental data and the previous numerical results of Houda. The cyclic response of the systems is shown in terms of soil arching and settlements. The decrease in pile efficacy and the cumulative settlements are exhibited. The HYP model allows to better simulate the soil arching mechanisms inside the LTP than the CYsoil model used in the Houda’s research work. A good concordance between the proposed numerical results and the experimental data was obtained.

This study aims to investigate the effect of plastic fine content on the undrained monotonic behavior of sandy soils (mixtures of host sand and various plastic fine content from 0 to 25%), and in particular, their static liquefaction resistance (undrained shear strength). Illite Arvel is considered as a plastic fine to add to the host sand, the Fontainebleau sand. Binary mixture samples are reconstituted by using the moist tamping technique. A series of undrained triaxial tests were carried out to study the influence of different parameters, such as the fine content, the initial density index, the confining pressure, and the over-consolidation ratio (OCR) on the behavior of sandy soil mixture. Based on the results acquired from these tests, the liquefaction susceptibility of the sandy soil is discussed by using Chinese criteria.