Soil Retaining Wall Research Articles

Cost analysis of reinforced soil walls

Reinforced soil structures are both economically and technically very advantageous over their conventional counterparts, especially under poor soil conditions, and also when there are space and property line limitations. Moreover, reinforced soil structures provide numerous other indirect savings and conveniences, such as speedy construction time, ease in construction methods, graceful appearances, etc. In this presentation, a systematic method of determining the possible cost of a reinforced soil-retaining wall is described, and an estimate of cost breakdown is given on the basis of height and length of the retaining wall. Relative economy of reinforced soils, in comparison with conventional and other types of retaining walls, is also discussed. For purposes of illustration, several case studies of cost analyses and numerical examples are also included.

Numerical investigation of controlled yielding of soil-retaining wall structures

Geosynthetic materials used as compressible layers against rigid wall structures can be employed to induce controlled yielding of the retained soil backfill during construction, and thereby ensure minimum lateral earth pressures on the structure. This paper describes two sets of numerical simulations that were carried out to model the controlled yielding concept. The simulations used a finite-element method together with a hyperbolic constitutive soil model. The first set of simulations was used to validate the FEM approach by comparing in the literature. The second of simulations was carried out to generate preliminary design charts for the selection of stiffness and thickness of compressible layers placed against rigid walls retaining well-graded sand backfills compacted to a range of densities.

Laboratory Model Study on Geosynthetic Reinforced Soil Retaining Walls

Reinforced soil technologies have been extensively used during the past few decades in the construction of embankments and retaining walls. A large variety of reinforcing materials emerged and have been developed for construction purposes, including: metal strips, bar mats, geotextile sheets, geogrids, etc, Fullscale experiments and centrifugal and reduced‐scale laboratory model studies have been performed to provide a rational basis for design methods of reinforcing systems using quasi‐inextensible steel strips and bar mats. However, laboratory model studies on the behavior of reinforced soil walls with more extensible reinforcements, such as geotextiles and geogrids, have been rather limited. These studies have encountered fundamental difficulties pertaining to similitude requirements and specifically appropriate modeling of the reinforcing materials, as well as to the proper instrumentation of extensible reinforcing elements to measure the mobilized tension forces. This paper describes the results of a laboratory model study on the performance, behavior and failure mechanisms of reinforced soil‐retaining walls using different reinforcing materials, namely: woven polyester geotextile strips, plastic grids, and nonwoven geotextile strips. The model walls were instrumented to obtain measurement of stresses in the reinforcements, displacements at different points along the reinforcements, displacements of the facing, and to identify, using colored sand, the failure surface in the soil. Experimental results indicate that the confinement of the reinforcement has a major effect on the structure performance. The paper also outlines practical conclusions that can be drawn for design purposes.