Experimental approach to assess waste containers stability during pluvial flooding events

Abstract

In recent years, several studies in the field of urban resilience have focused on the impacts of extreme climate events on urban services and their critical and vulnerable infrastructures. Before solid waste is transported and prepared for its disposal, it must be collected in various ways. One of the most common is the use of containers placed in urban and peri-urban areas, usually near road edges and carriageways. This collection system is common in large cities, such as the case of the metropolitan area of Barcelona, which this study focuses on. When an urban flood occurs, these containers may lose their stability, thereby allowing debris (i.e., solid waste contained) to escape from them and contaminate the flood water. The containers themselves can also be dragged away together or separately from their contents. These large urban objects being carried by the water flow can drastically limit the hydraulic capacity of a road section, exacerbating the possible effects of a flood. This hazard is greatest upstream of culverts, bridges, or other places potentially blocked by debris. On the other side, solid waste can clog inlets and sewers if it comes out of the container after it loses stabil-ity, thereby worsening the drainage system functioning and contributing to exacerbate the flood impacts. Consequently, waste containers stability when exposed to flooding is definitely an environmental, safety and health concern to be addressed. In a study carried out within the European RESCCUE project (https://toolkit.resccue.eu/) potentially unstable containers within the whole city of Barcelona were identified through a theoretical (about their stability) and numerical analysis of the hydrodynamic conditions of the overland flows produced by vari-ous historical and project rains. This work, on the other hand, presents some preliminary results related to a series of experimental tests carried out in the hydraulics laboratory of the Universitat Politècnica de Cata-lunya (UPC) through a full-scale physical model. The laboratory activities aimed to analyse the stability of some containers used in Barcelona for the waste collection and considered different flow rates on the sur-face, as well as different levels of filling of the containers. The final aim of this study is confirm the results provided by RESCCUE project in order to adopt specific measures to minimize the impacts of containers instability during pluvial flood events. The study was carried out as part of the FAVOR (Flood hazard analysis considering vehicles and other floating elements in urban areas) project (2020-2023) funded by the National Research Agency of the Spanish Ministry of Science, Innovation and University.