Structural performance of a medium-span RC three-sided culvert based on field measurements and numerical analyses

Abstract

The structural performance and soil–structure interaction mechanism of a 7.3 m span, reinforced concrete (RC), three-sided culvert (TSC) with flat top slab are investigated through field monitoring and numerical analyses. The culvert was instrumented with six pressure cells and 14 strain gauges. Data were collected during and after construction. Two-dimensional finite element models were validated against the field measurements. The validated numerical models were then employed to evaluate the effects of the foundation soil condition (yielding or non-yielding) on the applied earth pressures along the culvert profile and the induced straining actions at the base of the culvert’s sidewall. Moreover, the structural performance of TSCs at the ultimate loading condition has been evaluated from the numerical model. The results indicate that for TSC supported on yielding foundation soil, significant bending moment develops at the sidewall base and that the assumption of hinged connection at the base is only realistic for the case of TSCs supported on rock (non-yielding foundation). In addition, the precast unit width was found to have minimal influence on the failure mechanism and the ductility of the precast unit. Finally, failure may occur at a lower backfill height for the non-yielding foundation case relative to the yielding foundation case.