Geosynthetic reinforced soil for low-volume bridge abutments.
-
2012-01-01
-
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final report.
-
Corporate Publisher:
-
Abstract:This report presents a review of literature on geosynthetic reinforced soil (GRS) bridge abutments, and test results and analysis from two
field demonstration projects (Bridge 1 and Bridge 2) conducted in Buchanan County, Iowa, to evaluate the feasibility and cost
effectiveness of the use of GRS bridge abutments on low-volume roads (LVRs). The two projects included GRS abutment substructures
and railroad flat car (RRFC) bridge superstructures. The construction costs varied from $43k to $49k, which was about 50 to 60% lower
than the expected costs for building a conventional bridge. Settlement monitoring at both bridges indicated maximum settlements ≤1 in.
and differential settlements ≤ 0.2 in transversely at each abutment, during the monitoring phase.
Laboratory testing on GRS fill material, field testing, and in ground instrumentation, abutment settlement monitoring, and bridge live
load (LL) testing were conducted on Bridge 2. Laboratory test results indicated that shear strength parameters and permanent
deformation behavior of granular fill material improved when reinforced with geosynthetic, due to lateral restraint effect at the soilgeosynthetic
interface. Bridge LL testing under static loads indicated maximum deflections close to 0.9 in and non-uniform deflections
transversely across the bridge due to poor load transfer between RRFCs. The ratio of horizontal to vertical stresses in the GRS fill was
low (< 0.25), indicating low lateral stress on the soil surrounding GRS fill material. Bearing capacity analysis at Bridge 2 indicated
lower than recommended factor of safety (FS) values due to low ultimate reinforcement strength of the geosynthetic material used in
this study and a relatively weak underlying foundation layer. Global stability analysis of the GRS abutment structure revealed a lower
FS than recommended against sliding failure along the interface of the GRS fill material and the underlying weak foundation layer.
Design and construction recommendations to help improve the stability and performance of the GRS abutment structures on future
projects, and recommendations for future research are provided in this report.
-
Format:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: