Geosynthetic-Reinforced Soil Bridge Abutments

Abstract

Geosynthetic-reinforced soil (GRS) bridge abutments have been used on a number of bridge projects over the past decade. This adaptation of reinforced soil technology to bridge structures and their approach fills offers an excellent opportunity to simplify construction, reduce construction time, and reduce cost on structures for which this technology is appropriate. This design concept, in which the actual bridge superstructure rests upon the GRS abutment wall, minimizes differential settlement and eliminates the problematic “bridge bump” found on many structures. The technology has been adapted to both road and trail bridges. The basic design concept of GRS used in bridge abutment applications was evaluated, along with its advantages and disadvantages. Some selected case histories of GRS bridge abutments on low-volume roads and trails in Alaska and California were considered. In addition, the Mammoth bridges, in the mountains of northern California, with high design snow loads and high horizontal peak ground accelerations, afforded an opportunity to design, construct, and monitor GRS-supported spread-footing abutments under difficult service conditions.

Ingenuity in Geotechnical Design Using Geosynthetics

“…A comparatively recent approach involves the use of integral Geosynthetic Reinforced Soil (GRS) abutments, which support the bridge load by footings placed directly on a geosynthetic-reinforced wall, eliminating the use of traditional deep foundations altogether (Zornberg et al 2001b, Keller and Devin 2003, Wu et al 2006. Some additional advantages include their flexibility, and consequently added ability to withstand differential settlements and seismic loads as well as their ability to alleviate the bridge "bumps" commonly occurring at the two ends of a bridge supported by piles.…”

Geotechnical Problems Of The Foundation Of Road Embankments By The Bridge Structures

“…It is becoming increasingly popular to replace the traditional massive concrete bridgeheads with pillars, behind which the wall of reinforced soil is implemented. The reinforced soil is also used as the ending of embankment, on both sides of the wall bridgehead, or as the side walls of the bridgeheads [8].…”

“…During the recent years, the publications and design studies have included a number of individual and innovative propositions of the solutions, leading to the elimination or reduction of the foundation problems in regard to the engineering structure adjacent to the earth structure, in access zone to the bridge [6,8].…”

Effect of reinforcement spacing on the performance of bridge abutment by scaled model test

“…Mechanically stabilized earth using geosynthetic (GMSE) is the reinforced soil with larger reinforcement spacing, which is commonly seen in reinforced structures such as retaining walls, railway subgrades, slopes, etc. According to the research of Adams et al (2007a;2007b), Keller and Devin (2003), and Saghebfar et al (2017), compared with GMSE, GRS shows advantages in higher strength, lower lateral deformation and tolerance of differential settlements due to its smaller reinforcement spacing and better compaction of backfill material. Recently, usage of GRS technology in bridge-supporting structures have been extensively increased, particularly for small single-span bridges (Adams et al, 2011).…”