The object of this paper is to reveal information on maintenance practices of civil construction firms and to comment on them in relation to conventional economic theory. The paper is in three parts: a descriptionption of the maintenance requirements (ie demand), an outline of maintenance undertaken (ie supply) and a discussion of conventional, neo-classical, economic theory regarding these findings.
A distorted one-tenth scale laboratory model of a railway track sfructure was built in order to verity a linear two-dimensional analytical model based on the Abaqus finite element code. The structure was loaded with a moving doubleaxled vehicle with a sprung mass oscillating in the vertical plane without any pitching. The foundation consisted of a ballast layer and supporting base, all made of polymers that were assumed to be homogenous and isotropic. The primary purpose of the linear model was to obtain a basic understanding. of the' behaviour of such a structure prior to establishing more sophisticated models.