Analysis of Equilibrium Morphologies Downstream of a PK Weir Structure
Michele Palermo, Brian M. Crookston, Stefano Pagliara
Abstract
Scour processes downstream of hydraulic structures are some of the more challenging problems for hydraulic engineers because of the potential for scour to cause incidents and failures with catastrophic consequences to society and the surrounding environment. In addition, urbanization and climate changes frequently cause flow capacity deficiencies for various hydraulic structures to safely pass extreme flood events and meet current regulations. In this regard, PK weirs represent an innovative control structure that can be successfully used in new and rehabilitation projects to fulfill this trend of increasing discharge capacity demand. Nevertheless, the effects of an increased discharge on local scour are still under-explored. In order to fulfil this gap of knowledge, a dedicated laboratory model was built and experimental tests were conducted to analyse the scour mechanism downstream of a PK weir structure. One uniform noncohesive granular bed material was tested under different combinations of discharge and tailwater depth. This paper presents a preliminary analysis of the scour morphology downstream of a PK weir, focusing on the effects of different tested variables at equilibrium conditions.