Numerical Analyses on the Behavior of Geosynthetic-Reinforced Soil: Integral Bridge and Integrated Bridge System

Geosynthetic-reinforced soil (GRS) technology has been used worldwide since the 1970s. An extension to its development is the application as a bridge abutment, which was initially developed by the Federal Highway Administration (FHWA) in the United States, called the GRS—integrated bridge system (GRS-IBS). Now, there are several variations of this technology, which includes the GRS Integral Bridge (GRS-IB) developed in Japan in the 2000s. In this study, the GRS-IB and GRS-IBS are examined. The former uses a GRS bridge abutment with a staged-construction full height rigid (FHR) facing integrated to a continuous girder on top of the FHR facings. The latter uses a block-faced GRS bridge abutment that supports the girders without bearings. In addition, a conventional integral bridge (IB) is considered for comparison. The numerical analyses of the three bridges using Plaxis 2D under static and dynamic loadings are presented. The results showed that the GRS-IB exhibited the least lateral displacement (almost zero) at wall facing and vertical displacements increments at the top of the abutment compared to those of the GRS-IBS and IB. The presence of the reinforcements (GRS-IB) reduced the vertical displacement increments by 4.7 and 1.3 times (max) compared to IB after the applied general traffic and railway loads, respectively. In addition, the numerical results revealed that the GRS-IB showed the least displacement curves in response to the dynamic load. Generally, the results revealed that the GRS-IB performed ahead of both the GRS-IBS and IB considering the internal and external behavior under static and dynamic loading.

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A Study of the Effects of Geosynthetic Reinforced Soil and Reinforcement Length on GRS Bridge Abutment

Applied Sciences ◽

10.3390/app112311226 ◽

2021 ◽

Vol 11 (23) ◽

pp. 11226

Author(s):

Myoung-Soo Won ◽

Christine Patinga Langcuyan

Keyword(s):

Deformation Behavior ◽

Numerical Models ◽

Vertical Displacement ◽

Reinforced Soil ◽

Integral Bridge ◽

Geosynthetic Reinforced Soil ◽

Bridge Abutment ◽

Staged Construction ◽

Vertical Displacements ◽

Lateral Displacements

The geosynthetic reinforced soil (GRS) bridge abutment with a staged-construction full height rigid (FHR) facing and an integral bridge (IB) system was developed in Japan in the 2000s. This technology offers several advantages, especially concerning the deformation behavior of the GRS-IB abutment. In this study, the effects of GRS in the bridge abutment with FHR facing and the effects of geosynthetics reinforcement length on the deformation behavior of the GRS–IB are presented. The numerical models are analyzed using the finite element method (FEM) in Plaxis 2D program. The results showed that the GRS–IB model exhibited the least lateral displacements at the wall facing compared to those of the IB model without geosynthetics reinforcement. The geosynthetics reinforcement in the bridge abutment with FHR facing has reduced the vertical displacement increments by 4.7 times and 1.3 times (maximum) after the applied general traffic loads and railway loads, respectively. In addition, the numerical results showed that the increase in the length-to-height (L/H) ratio of reinforcement from 0.3H to 1.1H decreases the maximum lateral displacements by 29% and the maximum vertical displacements by 3% at the wall facing by the end of construction. The effect of the reinforcement length on the wall vertical displacements is minimal compared to the effect on the wall lateral displacements.

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16-Year Performance Update: Geosynthetic Reinforced Soil Walls as Integral Bridge Abutment Walls

Geotechnical Frontiers 2017 ◽

10.1061/9780784480458.011 ◽

2017 ◽

Author(s):

Michael R. Simac ◽

David J. Elton

Keyword(s):

Reinforced Soil ◽

Integral Bridge ◽

Geosynthetic Reinforced Soil ◽

Soil Walls ◽

Bridge Abutment ◽

Reinforced Soil Walls

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Geosynthetic Reinforced Soil Walls As Integral Bridge Abutment Walls

Earth Retention Conference 3 ◽

10.1061/41128(384)62 ◽

2010 ◽

Author(s):

Michael R. Simac ◽

David J. Elton

Keyword(s):

Reinforced Soil ◽

Integral Bridge ◽

Geosynthetic Reinforced Soil ◽

Soil Walls ◽

Bridge Abutment ◽

Reinforced Soil Walls

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Comparison of Field Behavior with Results from Numerical Analysis of a Geosynthetic Reinforced Soil Integrated Bridge System Subjected to Thermal Effects

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119899043 ◽

2020 ◽

Vol 2674 (1) ◽

pp. 294-306

Author(s):

Arshia Taeb ◽

Phillip S.K. Ooi

Keyword(s):

Pressure Fluctuations ◽

Axial Loading ◽

Reinforced Soil ◽

Element Analysis ◽

Vertical Pressure ◽

Geosynthetic Reinforced Soil ◽

End Wall ◽

Cyclic Straining ◽

Toe Pressure ◽

Bridge System

When subjected to ambient daily temperature fluctuations, a 109.5 ft-long geosynthetic reinforced soil integrated bridge system (GRS-IBS) was observed to undergo cyclic straining of the superstructure. The upper and lower reaches of the superstructure experienced the highest and lowest strain fluctuation, respectively. These non-uniform strains impose not only axial loading of the superstructure but also bending. Pure axial loading in a horizontal superstructure will cause the footings to slide. However, bending in the superstructure will cause the footings to rotate thereby inducing cyclic fluctuations of the vertical pressure beneath the footing and also lateral pressure behind the end walls. Measured vertical footing pressure closest to the stream experienced the greatest daily pressure fluctuation (≈ 2,500–3,000 psf), while that nearest the end wall experienced the least. The toe pressure fluctuations seem rather large. That these large vertical pressure fluctuations are observed in a tropical climate like Hawaii when no other GRS-IBS in temperate regions has reported the same (or perhaps higher fluctuation) is indeed surprising. The larger these pressures are, the greater the likelihood of inducing cyclic-induced deformations of the GRS abutment. A finite element analysis of the same GRS-IBS was performed by applying an equivalent temperature and gradient to the superstructure over the coldest and hottest periods of a day to see if the field measured values of pressures are reasonable and verifiable, which indeed they were. This methodology is novel in the sense that the effects of axial load and bending of the superstructure are simulated using measured strains rather than measured temperatures.

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