Indirect estimates of flexural strain in concrete sidewalks induced by vertical movement

Abstract

This paper examines different numerical methods to estimate flexural strain from surface elevation measurements on concrete sidewalks. Surface elevations, along a typical concrete sidewalk cross section, were monitored on a monthly basis as part of a study to determine the cracking mechanism of concrete sidewalks. These measurements were carried out in Calgary, Edmonton, and Camrose, Alberta, between 1993 and mid-1995. Finite difference, cubic spline, polynomial fit, and Fourier series methods of analyses are described for an indirect estimation of flexural strains in sidewalks. The sensitivity of these methods to measurement error is discussed. The Fourier series method is found to be the best procedure to analyse sidewalk surface elevation data for flexural strains estimates. The numerical methods to indirectly determine strain are best suited for those circumstances where installation of strain gauges is difficult, expensive, or impossible.Key words: concrete sidewalks, indirect estimates of flexural strain.