| dc.description.abstract | Millions of square feet of mechanically stabilized earth retaining wall are constructed
annually in the United States. When used in highway fill applications in conjunction with
bridges, these MSE walls are typically constructed with a roadside barrier system supported
on the edge of the wall. This barrier system generally consists of a traffic barrier or bridge rail
placed on a continuous footing or structural slab. The footing is intended to reduce the
influence of barrier impact loads on the retaining wall system by distributing the load over a
wide area and to provide stability for the barrier against sliding or overturning. The proper
design of the roadside barrier, the structural slab, and the MSE wall system requires a good
understanding of relevant failure modes, how barrier impact loads are transferred into the wall
system, and the magnitude and distribution of these loads.
In this study, a procedure is developed that provides guidance for designing: 1. the
barrier-moment slab, 2. the wall reinforcement, and 3. the wall panels. These design
guidelines are developed in terms of AASHTO LRFD procedures. The research approach
consisted of engineering analyses, finite element analyses, static load tests, full-scale dynamic
impact tests, and a full-scale vehicle crash test. It was concluded that a 44.5 kN (10 kips)
equivalent static load is appropriate for the stability design of the barrier-moment slab system.
This will result in much more economical design than systems developed using the 240 kN
(54 kips) load that some user agencies are using. Design loads for the wall reinforcement and
wall panels are also presented. | en |
