Special-shape similitude law of a soil‒pile–structure model for centrifuge shaking table tests

For soil‒pile–structure centrifuge shaking table tests, the stiffness of the structure is changed by adjusting the inertia moment of the cross section to meet dynamic similitude criteria when the soil part of the scale model and prototype is commonly the same. However, this may cause significant difficulties when manufacturing the scale model. To solve this problem, a special-shape similitude law was proposed for the design of soil‒pile–structure scale models in centrifuge shaking table tests by adjusting geometric similitude ratios in the horizontal vibration direction. The design of similitude relationships for a pile foundation bridge pier was investigated. A series of numerical simulations were performed to validate the proposed special-shape similitude law through comparison with the conventional similitude law. A parametric study was conducted to further demonstrate the accuracy of the special-shape similitude law under different conditions. The relative errors of the structure part between the special-shape scale model and conventional scale model are all less than 10%, and those of the soil part of the special-shape scale model are much smaller than those of the conventional scale model. The prediction accuracy of the special-shape scale model remains good under different foundation strengths and seismic intensities.