Stochastic–dynamic modeling of chute slabs under spillway flows

Amid the growing energy–water nexus crisis, large dams are being reconsidered as viable solutions despite significant environmental concerns. A critical and enduring issue with large dams is the threat they pose to downstream communities and infrastructure in the event of structural failure. The Oroville Dam spillway incident, where inadequate maintenance led to uplift forces that exceeded the structural capacity of a chute slab, causing severe damage, has renewed the focus on the structural stability of spillway components. This study argues that conventional methods, which rely on averaged values and empirical coefficients, may be inadequate for accurately capturing the dynamical stresses on spillway chutes induced by turbulent flow conditions. We propose a novel approach using stochastic simulation schemes to generate synthetic time series of velocity, which are then applied to a differential equation governing the chute slab oscillations. Through a hypothetical case study inspired by the Oroville incident, we demonstrate two key issues: first, that the conventional approach significantly underestimates the maximum stresses experienced by chute slabs under dynamic uplift pressures; and second, that the stochastic structure of the velocity, particularly the variance and persistence, plays a major role in determining the maximum stress.