Análisis a escala de laboratorio del lavado de sedimentos depositados en carreteras

Abstract presented to Spanish national conference META2024. Abstract: Sediment wash-off by surface runoff is a common problem in urban areas and can have several negative impacts on the environment, infrastructure, and people's quality of life. This paper analyzes sediment wash-off through a large-scale laboratory physical model under different rainfall/runoff scenarios and high sediment loads. The facility, which includes a rainfall generator, an impermeable street surface, a drain inlet, and a manhole, allows for the realistic and accurate simulation of the processes involved in the wash-off phenomenon, without the uncertainties present in real urban catchments. The methodology considered three phases: characterization of the granulometry and pollutant content of the sediment load distributed on the model surface; wash-off tests in the physical model using different initial sediment loads and rainfall intensities of 30 and 50 mm/h; and final analysis of sediment loads in the drainage system components (remaining on the street surface, deposited in the drain inlet, and washed away by the flow discharged into the manhole based on manual samples). The results are enabling a detailed analysis of the behavior of different sediment grain size fractions based on the initially distributed load on the surface and rainfall intensity, as well as tracing the transport of heavy metals through the various parts of the model. The complete experimental campaign aims to increase knowledge about contaminant wash-off processes in urban catchments, supporting the development of new models to optimize the design and maintenance of urban drainage systems.