Geosynthetic Reinforced Soil Foundation Research Articles

English

The purpose of this study is to investigate and quantify the load-carrying capacity of square footings supported by foundations made of geosynthetic reinforced soil (GRS). A significant area of research in geotechnical engineering is the estimation of the burden-carrying limits of square feet laying on geosynthetic reinforced soil foundations as a green building technology. This research aims to investigate the load-carrying capacity of square footings supported by geosynthetic reinforced soil foundations, with a particular focus on how these foundations can be used in environmentally friendly building methods. Geosynthetic-supported soil establishments are implicitly reasonable holders. A square footing is set on geosynthetic reinforced soil in a loading frame and compressed. (Group 1: GRS system with 6 cm reinforcement spacing, N = 17; Group 2: GRS system with 4 cm reinforcement spacing). For test size estimation, the pre-test power and certainty spans were set at 80% and 95% separately. The GRS foundation system with 4 cm reinforcement spacing outperforms the GRS foundation system with 6 cm spacing in tests. Closer reinforcement spacing improves square footing bearing capacity. The results of this study will add to upgrading the comprehension of geosynthetic-supported establishment frameworks and their true capacity as an innovation for developing green structures. The discoveries will give significant bits of knowledge to specialists, planners, and development experts in planning feasible and harmless to the ecosystem structures while guaranteeing underlying respectability and security.

Predicting the settlement of geosynthetic-reinforced soil foundations using evolutionary artificial intelligence technique

In order to ensure safe and sustainable design of geosynthetic-reinforced soil foundation (GRSF), settlement prediction is a challenging task for practising civil/geotechnical engineers. In this paper, a new hybrid technique for predicting the settlement of GRSF has been proposed based on the combination of evolutionary algorithm, that is, grey-wolf optimisation (GWO) and artificial neural network (ANN), abbreviated as ANN-GWO model. For this purpose, the reliable pertinent data were generated through numerical simulations conducted on validated large-scale 3-D finite element model. The predictive power of the model was assessed using various well-established statistical indices, and also validated against several independent scientific studies as reported in literature. Furthermore, the sensitivity analysis was conducted to examine the robustness and reliability of the model. The results as obtained have indicated that the developed hybrid ANN-GWO model can estimate the maximum settlement of GRSF under service loads in a reliable and intelligent way, and thus, can be deployed as a predictive tool for the preliminary design of GRSF. Finally, the model was translated into functional relationship which can be executed without the need of any expensive computer-based program.

A Generic Design Protocol for Geosynthetic Reinforced Soil Foundation

This technical note presents a generic step-by-step design protocol based on consideration of bearing capacity of reinforced soil foundation (RSF) on a level ground. The technical note begins with a synopsis of notable studies on bearing capacity of geosynthetic reinforced soil (GRS) and a brief description of an analytical model for load-carrying capacity of closely-spaced soil-geosynthetic composites. The generic RSF design protocol was developed based on findings of the notable studies and the analytical model. Specifically, the design protocol determines (i) reinforcement configuration of RSF (including reinforcement depths, spacing, and width), (ii) required reinforcement stiffness and strength for selection of reinforcement in RSF, and (iii) the increase in ultimate bearing capacity of RSF if the width of RSF is increased to fulfill design requirements A design example for RSF of a GRS bridge abutment is also given to illustrate how the design protocol can be applied.

Behavior of Geosynthetic Reinforced Soil Foundation Systems Supported on Stiff Clay Subgrade

A series of laboratory model tests was performed to investigate the behavior of geosynthetic reinforced stiff clay foundation systems under circular loading. The footing consisted of a rigid circular steel plate with a diameter of 150 mm. Five different series of tests were performed in both homogeneous (clay or sand) and layered configurations. The tests used planar geogrid and three-dimensional geocell reinforcements. Test results indicate that both types of reinforcements substantially improve the performance of the stiff clay foundation bed. A maximum threefold improvement was observed in bearing pressure, depending on the reinforcement type. However, geocell was found to be the most advantageous soil reinforcement technique, giving maximum performance improvement.

Mitigating the bridge end bump problem: A case study of a new approach slab system with geosynthetic reinforced soil foundation

The Louisiana Department of Transportation and Development (LA DOTD) has initiated a major effort to minimize the bridge end bump problem associated with the differential settlement. As a result, a new design for the approach slab was proposed, which requires increasing the slab flexural rigidity (EI), and using reinforced soil foundation (RSF) to support the slab and traffic loads at the roadway pavement/approach slab joint (R/S joint). The Bayou Courtableau Bridge was selected as a demonstration project to monitor, evaluate, validate, and verify the new bridge approach slab design method. The west approach slab was designed using the proposed design method with slab thickness of 406 mm (16 in.), while the east approach slab was designed using the traditional design method with slab thickness of 305 mm (12 in.). The pavement end side of the west approach slab was supported by a 1.2-m (4.0-ft.) wide strip footing with the soil underneath it was reinforced by six layers of geogrid placed at a vertical spacing of 305 mm (12 in). Two static load tests were conducted on both the west and east approach slabs at two different times after construction. The test results indicated that the west approach slab (with new design) lost most of its supports from the soil; while the east approach slab (with traditional design) kept losing its contacts from the soil starting from the bridge side towards the pavement side after about a year and half. The roughness profiles demonstrated better performance of the new approach slab system with much lower International Roughness Index (IRI) values.

Mitigating the bridge end bump problem: A case study of a new approach slab system with geosynthetic reinforced soil foundation

The Louisiana Department of Transportation and Development (LA DOTD) has initiated a major effort to minimize the bridge end bump problem associated with the differential settlement. As a result, a new design for the approach slab was proposed, which requires increasing the slab flexural rigidity (EI), and using reinforced soil foundation (RSF) to support the slab and traffic loads at the roadway pavement/approach slab joint (R/S joint). The Bayou Courtableau Bridge was selected as a demonstration project to monitor, evaluate, validate, and verify the new bridge approach slab design method. The west approach slab was designed using the proposed design method with slab thickness of 406 mm, while the east approach slab was designed using the traditional design method with slab thickness of 305 mm. The pavement end side of the west approach slab was supported by a 1.2-m wide strip footing with the soil underneath it was reinforced by six layers of geogrid placed at a vertical spacing of 305 mm. Two static load tests were conducted on both the west and east approach slabs at two different times after construction. The test results indicated that the east approach slab (with traditional design) kept losing its contacts from the underneath embankment soil starting from the bridge side towards the pavement side after about a year and half. Meanwhile, the west approach slab (with new design) lost most of its supports from the underneath embankment soil, but with less observed faulting at the R/S joint and improved rideability [i.e., lower International Roughness Index (IRI) values]. The field monitoring program at Bayou Courtableau Bridge demonstrated much better performance of the new approach slab design system (west approach slab) compared to traditional design (east approach slab).

Discussion of “Large Model Spread Footing Load Tests on Geosynthetic Reinforced Soil Foundations” by Michael T. Adams and James G. Collin

Discussion of “Large Model Spread Footing Load Tests on Geosynthetic Reinforced Soil Foundations” by Michael T. Adams and James G. Collin

Large Model Spread Footing Load Tests on Geosynthetic Reinforced Soil Foundations

The potential benefits of geosynthetic reinforced soil foundations are investigated using large-scale model footing load tests. A total of 34 load tests were performed to evaluate the effects of single and multiple layers of geosynthetic reinforcement placed below shallow spread footings. Two different geosynthetics are evaluated: a stiff biaxial geogrid and a geocell. Parameters of the testing program include the number of reinforcement layers, spacing between reinforcement layers, the depth to the first reinforcement layer, plan area of the reinforcement, the type of reinforcement, and soil density. Test results indicate that the use of geosynthetic reinforced soil foundations may increase the ultimate bearing capacity of shallow spread footings by a factor of 2.5.