Abstract An international educational initiative to facilitate the exposure of geosynthetics to undergraduate civil engineering students has been conducted by the International Geosynthetics Society (IGS) for over a decade. Geosynthetics is a comparatively new topic within geotechnical engineering and, consequently, has only been sporadically introduced into undergraduate Civil Engineering curricula. In particular, geotechnical engineering professors themselves may have not been exposed to the basics of geosynthetics to be able to comfortably transfer such knowledge to their students. As part of this educational program, civil engineering professors are invited to take a course on geosynthetics, for which they receive fellowships covering their expenses. The course also includes complementary components such as a workshop consisting of practical demonstrations, pedagogical material, and technical documents. Implementation of the program involves multiple parties, including the IGS, its national chapters, and geosynthetics industry, who are allotted the responsibilities of supporting the program instructors, offering practical project-oriented input. This paper describes the course structure, the educational tools employed, the impact on the program caused by the pandemic, and results from feedback surveys that assessed how the knowledge on geosynthetics acquired by the participants was transferred to their students in terms of new courses on geosynthetics, inclusion of geosynthetics topics in existing undergraduate disciplines, etc. Emphasis is given on the experience of the Brazilian Chapter of IGS, which has already conducted programs. The educational outcomes of the programs currently offered are being evaluated and they suggest excellent acceptance of the course by participants and undergraduate students at the universities.

Abstract Geotextile tubes can be used to dewater materials such as sludge, sediments or residues aiming at reducing their moisture contents to acceptable levels. The tube filling process can be carried out using one or several filling stages, and the number of stages can influence the tube behaviour in terms of dewatering rate, final shape and geotextile strains, for instance. In this research, laboratory tests were carried out on nonwoven geotextile tubes for the dewatering of a fine-grained material using different numbers of filling stages. The behaviour of the tube was monitored by instrumentation to assess tube geometry, pore pressures, total stresses at the tube base, geotextile strains and retention capacity. Evaluations of the accuracy of some available methods for the prediction of tube behaviour were also made. The results obtained showed that the increase in the number of filling stages resulted in larger final tube height, volume, geotextile strains as well as larger diameters of the soil particles that piped through the geotextile. Predictions of tube behaviour by available methods showed varying degrees of accuracy depending on the tube parameter considered. sludge levels rate instance research finegrained fine grained geometry pressures base capacity made height volume considered

Abstract In this case study of a soil nail retaining wall, the measured horizontal displacement is of the order of 0.023% H, where H is the excavation depth, while the two-dimensional Finite Element Method (FEM) analysis suggests horizontal displacements of the order of at least 0.5% H. This study aims to understand which parameters influence such displacements through a Sensitivity Analysis. In addition, the study compares results obtained through two-dimensional and three-dimensional FEM analyses for this case. It concludes that Young's Modulus (E) and the in-situ earth pressure coefficient (K0) are the two parameters that most influence such displacements. This study shows that Mohr Coulomb's perfectly plastic Elastic Constitutive Model is unsuitable for simulating this structure, which had minimal displacements in situ, suggesting the Hardening Soil model (Schanz et al., 1999) as a viable alternative. Compared to 3D analysis, 2D analysis showed significantly larger horizontal displacements. This led to the conclusion that 2D analysis in MEF is unsuitable for predicting lateral displacements unless a Reduction Factor (FR) ranging from 0.4 to 1.0 was applied.

Abstract The use of geosynthetic reinforcement in piled embankments over soft soils is an effective solution for the reduction of settlements and to increase the embankment stability. The most efficient position for the reinforcement layer is on the pile cap or head. However, a direct contact of the reinforcement with sharp edges may damage it, compromising its efficiency to transfer loads to the piles. This paper investigates the possibility of mechanical damages in geosynthetic reinforcements on pile caps by large scale laboratory tests. Tests with and without pieces of nonwoven geotextile protective layer between the caps and the reinforcements were executed. Wide strip tensile tests were performed on exhumed reinforcement specimens after the tests to assess tensile strength and stiffness variations. A statistical analysis of the results shows reductions in tensile strength of unprotected reinforcement layers of up to 28%. A mechanical damage index is introduced and its correlation with calculated reduction factors is investigated. The use of a piece of a thick geotextile layer to protect the reinforcement against mechanical damage can be effective. However, the geotextile product must be properly specified and installed with due care.

Abstract The use of granular column is one of the ground improvement methods used for soft soils. This method improves the foundation soils mechanical properties by displacing the soft soil with the compacted granular columns. The columns have high permeability that can accelerate the excess pore water pressure produced in soft soils and increase the undrained shear strength. When it comes to very soft soils, the use of granular columns is not of interest since these soils present no significant confinement to the columns. Here comes the encased columns that receive the confinement from the encasement materials. In this study, the influence of the column installation method on the surrounding soil and the encasement effect on the granular column performance were investigated using numerical analyses and experimental tests. The results show that numerical simulations can reasonably predict the behavior of both the encased column and the surrounding soil.