Research Activities: 2007


Project 2c: Alternative and Cost-Effective Bridge Approach Slabs - UMC



Complete  View Report: PDF

Sequential Number


Identification Number


Matching Research Agency

Missouri Department of Transportation (MoDOT) and University of Missouri - Columbia (UMC)


Principal Investigator

Vellore S. Gopalaratnam, Professor of Civil Engineering
E25401 Lafferre Hall
University of Missouri - Columbia
Columbia MO 65211

Student Involvement

One graduate student and one or more undergraduate students.

Project Objective

1.      Evaluate and document the current condition of existing bridge approach slabs with data available with MoDOT and gather additional data from a field study. From this study, the primary issues associated with the performance of approach slabs will be identified.

2.      Perform a best practice study of similar work done around the country and the practices adopted as a result of the study. Particularly review existing practices and innovations in Iowa, New Jersey and Louisiana DOTs.

3.      Study the effect of a) span length variation, b) slab thickness variation and c) end condition variations in order to design a slab that could potentially withstand varying geotechnical conditions.

4.      Study the feasibility of alternative solutions such as precast prestressed systems from both a design and construction cost perspective.

5.      Provide final design specifications and acceptance criterion for the proposed bridge approach slab system


Project Abstract

The primary objectives of the proposed project are to investigate the causes for any bumps at the end of the bridge approach slab, and to develop remedial measures or alternative designs for a replacement. It is clear that the problem stems from geotechnical considerations. In many instances compaction of soil under uncertain conditions when the bridge is being constructed may not be properly achieved. Hence, the geotechnical issues are likely to continue to exist. From the structures’ point of view, how we can design a bridge approach slab to save construction costs given a certain settlement is a question to answer.


Task Description



Anticipated Benefits

The anticipated results from this study can provide data that could potentially assist MoDOT engineers evaluate the performance of bridge approach slabs and the causes behind the bump’. The results will also provide MoDOT engineers with alternate structural solutions when a bridge approach slab is being considered.



Project Start Date:09/01/2008
Project End Date:



Relationship to other Research/Projects

This project, in partnership between UMKC and UMC, is a part of a larger collaborative research effort among MST, UMC, UMKC and MoDOT with a focus on two theme areas:

1. Extending service life of MoDOT’s existing bridges: performance goals, critical deficiency identification, cost-effective maintenance and preservation strategies (corrosion mitigation, strengthening, evaluation, etc.).

2. Optimizing MoDOT’s bridge design and construction for effective cost reduction: performance goals, consistent safety margins for bridge components, advanced materials for durability and performance enhancement, and accelerated construction technologies.


Technology Transfer Activities

The final product will be a report consisting of any test data available from other state DOTs, analysis of results, acceptance criteria for existing and the proposed bridge approach slab systems. It will also include recommendations for field implementation of such systems.

Transportation Research Board Keywords

Bridge approach slab, Prestressed Concrete, Fiber Reinforced Concrete, Design, Testing