Bending Capacity of Concrete-Encased Underground Electrical Duct Banks under Monotonic Loading: An Experimental Study

Abstract

The bending capacity of concrete-encased underground electrical duct banks has been the subject of considerable investigation using the load-structure method; however, the role of high-density polyethylene (HDPE) conduits and the thresholds of electrical duct banks has not been fully scrutinized. This study examines the bending behaviors of electrical duct banks subjected to monotonic vertical loading in a soil box using an advanced monitoring device to measure the conduit diameter change. An analysis of the experiment shows the effective role of HDPE conduits in improving the bending capacity of electrical duct banks. The results suggest 5% and 7.5% as the deformation rate thresholds with respect to the ultimate states of serviceability and bearing capacity, respectively. The threshold of the longitudinal curvature radius is determined to be 18000 m. Finally, the evolution trends of the stress and deformation rates of HDPE conduits are recommended for the monitoring indexes and control standards of electrical duct banks.