Modeling the Structural Response of Urban Sub-Surface Drainage Systems

摘要

In recent years, many City of Saskatoon (COS) roads have experienced premature failures. High watertables, increased precipitation, and poor surface drainage have led to increased moisture infiltration withinroad structures. Further deterioration of these aged pavements is due to heavy loadings year round inurban traffic. To address these issues, COS piloted sub-surface drainage and strain dissipation layerswithin some roads. These drainage systems were constructed with crushed Portland cement concrete(PCC) rock and conventional virgin crushed rock.Given the empirical nature of conventional road design methods currently employed by COS, thestructural benefits of drainage systems are difficult to quantify. A reliable methodology that directlyincorporates recycled materials, sub-structure drainage systems, and diverse field conditions is thereforeneeded. This paper contains a mechanistic analysis of the drainage systems piloted in rehabilitated COSpavement structures using a 3D non-linear orthotropic computational road structural model. Mechanisticanalysis was used to model peak surface deflections and normal and shear strains within the structure.Modeling results showed pavement structures constructed with a sub-structure drainage layercomprised of crushed PCC rock improved the structural performance of the road system in terms ofstrains under applied traffic loads. The road model was found to provide primary response predictionsthat correlate with deflections measured by heavy weight deflectometer both pre and post construction.Therefore, the road model used in this research is a reliable pavement engineering analysis tool, capableof predicting in-field structural behaviour of various road structures in diverse field state conditions.