Class-A prediction of three-sided reinforced concrete culverts and numerical investigation of the supporting strip footing geometry effect.

This paper presents three-dimensional finite element analyses conducted to optimise the instrumentation plan for monitoring the structural performance of reinforced concrete three-sided culverts (TSCs). Numerical models were developed for three TSCs with spans of 7.3, 10.4, and 13.5 m to establish the anticipated range of measurements. The TSCs were instrumented with 30 pressure cells and 56 strain gauges. Comparing the numerical predictions with field measurements of the 10.4-m-span TSC verified the adequacy of simulating the concrete behaviour as linear elastic for estimating the applied earth pressures. However, such simplification would lead to underestimating the induced strains in the culvert body in case cracks develop. In addition, Class-A predictions of soil pressures on the culvert were compared with the field measurements of a 7.3-m-span TSC. The calculated soil pressures agreed well with the field measurements. The measured and calculated earth pressures suggest a vertical arching factor of 1.05 at the final backfill height. The influence of the shallow foundation geometry was investigated employing the validated numerical model. It was found that the footing geometry has no influence on the applied earth pressures. However, the calculated stresses below the footing edge on the backfill side decreased as the footing flexibility increased. [ABSTRACT FROM AUTHOR]