Performance of Corrugated Steel Culverts Buried in Shallow Cover Depth and Subjected to Environmental Deteriorations

Abstract

Corrugated steel culverts (CSC) are key components of infrastructures to support water management and foundation integrity. Some installed culverts in North America are buried in shallow cover depths based on the engineering practices and they are exposed to environmental deteriorations in their service life. The primary goal of this research is to investigate the performance of corrugated steel culverts (CSC) buried subject to surface loads at shallow cover depths. The secondary goal of this research is to study environmental deterioration effects on the internal responses of CSC. Analytical models, finite element analysis (FEA) and numerical sensitivity studies are conducted to investigate the load transfer mechanisms and the development of internal CSC forces. The numerical results indicate that the complex geometry of the corrugated culvert subjects the crest and trough of corrugated profile to compression and tension due to the internal bending moment and thrust. These results indicate that the average strain response cannot account for the local peak strain response and this behavior necessitates corrections be applied to thrust calculations for buried culverts in shallow cover depth. The results achieved by sensitivity analysis indicates that the intact culvert/soil structure is an additive model and the thrust modification factor proposed for intact corrugated culverts buried in shallow cover depths. The impact of wall section loss due to corrosion is investigated and sensitivity analysis are used to identify variables that have a high impact and probability analysis conducted to predict the safety index and probability of failure of the corroded culvert buried in a shallow cover depth during the service life. The presence of soil voids, typically caused by erosion, is investigated by considering void size and position relative to the culvert. The study of void angle and void depth indicates that the loss of surface contact and support between the culvert and surrounding soil in the upper half of the culvert/soil structure is the key contributing factor to load transfer and deformation mechanisms.