Modular Road Plate System

Abstract

Concrete and asphalt are the most common materials used in permanent roadway pavements. Roadways are also constructed for temporary use in the resource industry, for remote site construction, and for disaster relief. Although temporary roads have been used for almost as long as permanent ones, little research has been done to optimize their design in view of their relatively short service lives or to investigate the advantages of constructing them with reusable materials or employing structural systems that require minimal subgrade preparation. With this in mind, the purpose of this study is to conduct research to determine the feasibility of a reusable, modular road plate system requiring minimal preparation of the subgrade. This thesis presents a literature review, summarizing the currently available products that perform a similar function and the methods currently available to design such products, including terramechanics and foundation design. Alternative concept designs for a modular road plate system are then introduced. Following this, a simple structural steel plate system is designed to resist vertical, traffic-induced loads using several methods. Specifically, an equivalent thickness method and finite element (FE) analysis are employed. Different loading conditions, soil conditions, and plate assemblies (i.e. boundary conditions) are compared. The different loading conditions include: single and multi-wheel loading, and centre versus edge loading of the plate. The different modelled plate assemblies include: single plates, four plates assembled with fixed connections, and four plates assembled with hinged connections. Structural steel plates are considered in the FE analysis study, in order to develop the design methodology, prior to applying it to the other materials or structural systems. Soil properties and panel thicknesses are studied covering a broad range of conditions under which temporary roadways may be built. Thirty scenarios are created from five soil types and six panel thicknesses. With the different loading and boundary conditions investigated, a total of 120 scenarios are analyzed in total, using several different FE models. The results from the FE analysis studies show that there is a significant difference between hinged and fixed connected panels, and that these different boundary conditions can be considered by modelling a single plate that is centre loaded (to represent a multi-plate system with fixed plate connections) or a single plate that is edge loaded (to represent a multi-plate system with hinged plate connections). The results of this research in general provide a practical framework for developing a modular road plate system constructed using any material or structural system under a range of soil and loading conditions.