Yewei Zheng

Numerical Investigation of Geosynthetic-Reinforced Soil Bridge Abutments under Static Loading

AbstractThis paper presents a numerical investigation of the performance of geosynthetic-reinforced soil (GRS) bridge abutments under static loading conditions. Simulations were conducted using a finite-difference program to model the Founders/Meadows GRS bridge abutment during construction and service. Simulated results are in good agreement with field measurements, including displacements, lateral and vertical earth pressures, and tensile strains and forces in reinforcement. The simulations also indicate that horizontal restraint from the bridge structure has a significant influence on abutment deflections. A parametric study was then conducted to investigate the performance of a single-span full bridge system with two GRS abutments, including effects of bridge contact friction coefficient, backfill soil relative compaction, backfill soil cohesion, reinforcement spacing, reinforcement length, reinforcement stiffness, and bridge load. Results indicate that backfill soil relative compaction, reinforcement...

Numerical Investigation of the Geosynthetic Reinforced Soil–Integrated Bridge System under Static Loading

AbstractThis paper presents numerical simulations of the performance of the Geosynthetic Reinforced Soil–Integrated Bridge System (GRS-IBS) under static loading conditions. Simulations were conduct...

Numerical Simulations for Response of MSE Wall-Supported Bridge Abutments to Vertical Load

In recent years, mechanically stabilized earth (MSE) walls have been proposed as support for bridge abutments on shallow foundations due to significant cost savings over conventional pile-supported designs. This paper presents new research on numerical modeling of a realistic MSE wall-supported bridge abutment using the finite difference program FLAC-2D. MSE abutments are typically subjected to much larger loads from bridge superstructures than conventional MSE walls. An MSE bridge abutment with a flexible wall facing is a complex system that includes granular backfill, reinforcement, concrete facing blocks, and the shallow foundation for the abutment structure. In the numerical simulations, soil-block, block-block, and soil-abutment interactions were simulated using interface elements and soil-geogrid interactions were simulated using cable elements. The MSE abutment is subjected to a vertical bridge load of 200 kPa. Results are presented for static conditions and include lower wall facing displacements, abutment structure settlements, maximum tensile forces in the reinforcement, lateral earth pressures, and vertical stresses under the abutment structure and at the soil foundation level. The numerical results are discussed with regard to practical field applications.

Numerical Study of Deformation Behavior for a Geosynthetic-Reinforced Soil Bridge Abutment under Static Loading

The geosynthetic-reinforced soil (GRS) bridge abutment is a new technology that has many advantages over traditional abutment designs, including cost savings, relatively easy and fast construction, and good performance with regard to differential settlements. The GRS bridge abutment is a complex system that includes a lower GRS wall, bridge seat, and upper GRS wall, with the bridge superstructure load applied directly to the backfill for the lower GRS wall. This paper presents numerical simulations of the static response of a typical GRS bridge abutment during construction and service. The numerical simulations include soil-reinforcement, soil-block, block-block, and soil-bridge seat interactions. Analyses were performed in stages to simulate the abutment construction process. A uniform surcharge load was applied on the bridge deck and approach roadway to simulate traffic loads during service. Results for construction and in-service conditions are presented and discussed, with particular focus on wall facing lateral displacements and bridge seat settlements. The effect of bridge load on the deformation behavior of the GRS bridge abutment was also investigated. Numerical results indicate that the abutment has good performance under static loading conditions with relatively small lateral deflection and settlement, and relatively large load bearing capacity.

Shaking Table Test of a Half-Scale Geosynthetic-Reinforced Soil Bridge Abutment

This paper presents an experimental study on the dynamic response of a half-scale geosynthetic-reinforced soil (GRS) bridge abutment system using a shaking table. Experimental design of the model specimen followed established similitude relationships for shaking table tests on reduced-scale models in a 1-g gravitational field, including scaling of model geometry, geosynthetic-reinforcement stiffness, backfill soil modulus, bridge load, and characteristics of the earthquake motions. The 2.7-m-high GRS bridge abutment was constructed using well-graded sand backfill, modular facing blocks, and uniaxial geogrid reinforcements with a vertical spacing of 0.15xa0m in both the longitudinal and transverse directions. A bridge beam was placed on the GRS bridge abutment at one end and on a concrete support wall resting on a sliding platform off the shaking table at the other end. The GRS bridge abutment system was subjected to a series of input motions in the longitudinal direction. Results indicate that the testing system performed well, and that the GRS bridge abutment experienced small deformations. For two earthquake motions, the maximum incremental residual facing displacement in model scale was 1.0xa0mm, and the average incremental residual bridge seat settlement in model scale was 1.4xa0mm, which corresponds to a vertical strain of 0.7 %.