Quantification of the effect of vehicle dynamic load on pavements for different truck configurations passing over a speed breaker considering contact loss nonlinearity

Vehicle–pavement interaction (VPI) dynamics under multi-axle trucks traversing speed breakers exhibit nonlinear behaviour due to tyre–road contact loss, whose implications for pavement response remain underexplored. This study investigates VPI dynamics for single-axle single-wheel (SASW), single-axle dual-wheel (SADW), and tandem-axle (TA) configurations using nonlinear sequential force-transfer framework. A planar multi-degree-of-freedom half-car model with lumped masses and linear suspension and tyre elements represents the vehicle, while a discretized viscoelastic pavement system models pavement deformation under moving loads. Vehicle dynamics are solved to obtain time-varying tyre–pavement interaction forces accounting for contact separation, subsequently applied to evaluate pavement response. The dynamic loading response are quantified using multiple established metrics. SADW exhibits very high rear-axle dynamic loads due to pitch-induced load transfer, whereas TA distributes loads across contact points, moderating peak deformation despite higher gross loading. Contact loss amplifies transient tyre forces, with sensitivity to speed-breaker geometry and operating speed. As all configurations exhibit dynamic amplification relative to static loading, design and maintenance recommendations near speed breakers are proposed, that aim to mitigate deterioration. The framework provides mechanistic basis for predicting pavement response under dynamic traffic loading, highlighting axle configuration, contact nonlinearity, and road geometry.