摘要: |
This report presents a numerical investigation of the behavior of steel strip-reinforced mechanically stabilized earth (MSE) direct bridge abutments under static loading. Finite element simulations were performed using an advanced two-surface bounding plasticity model based on critical state soil mechanics. Results of the simulations were found to be in good agreement with published laboratory and field measurements, including horizontal facing displacements and tensile forces in the reinforcement. A parametric study was then conducted to investigate the behavior of a full-scale direct MSE bridge abutment. The parameters considered were the horizontal distance of the footing behind the wall facing, backfill compaction, reinforcement length and spacing, and magnitude of bridge load. Results indicate that the aforesaid parameters have a significant influence on the horizontal facing displacements, bridge footing settlements, and axial strains in the reinforcements. A survey questionnaire on the current state-of-practice of direct and mixed MSE abutments was prepared and distributed to all the Departments of Transportation (DOTs) in the United States. Results obtained from the survey shed light on the percentage of use of direct and mixed MSE abutments by various DOTs, abutment height, type and dimensions of the facing element, type of reinforcement, proportioning of footing and pile in direct and mixed MSE abutments, respectively, and common problems experienced by DOTs with respect to construction and performance of MSE abutments in the field. |