Centrifuge modeling of the slow-cyclic and dynamic behaviors of a rigid structure resting on a rigid inclusions reinforced soft ground
Centrifuge modeling of the slow-cyclic and dynamic behaviors of a rigid structure resting on a rigid inclusions reinforced soft ground
The performance of a rigid inclusion (RI) foundation system was evaluated through quasi-static pushover and dynamic centrifuge tests. The analysed system considered a slender rigid structure resting on soft clay. The aim of the quasi-static pushover test was to explore the rocking response of the structure under large rotation angles, and the dynamic test examined the rocking-dominated behaviour of the structure under seismic and sinusoidal loading scenarios. The experiments were conducted at 50g using the geotechnical centrifuge at Gustave Eiffel University. The ground mass was constituted of three layers: a base layer of stiff sand, serving as the bearing substratum for the RIs; an intermediate soft clay layer in which the RIs were installed; and a surface sand layer acting as a load transfer platform (LTP). Seven aluminium tubular RIs were driven through the clay to reach the base sand layer. A stiff, cylindrical structure was positioned on top of the LTP, simulating a slender superstructure. In the quasi-static pushover test, a mechanical actuator applied a horizontal force at the centre of gravity to generate overturning moments and shear forces at the foundation level, as well as bending moments and axial loads in the RIs. In the dynamic test, the model was subjected to a sequence of base excitations. The system performance in both scenarios was assessed in terms of mobilized overturning moments, structure rotations, settlements, and internal forces in the RIs. During quasi-static pushover test, the system exhibits a markedly non-linear response, characterized by rotational stiffness degradation with increasing rotation and a cyclic overstrength associated with soil rounding and foundation uplift. Under dynamic loading, the response generally follows the monotonic pushover trend, with peak overturning moments remaining significantly lower than those obtained from quasi-static pushover tests.
Charbel NOHRA; Cristian SORIANO-CAMELO; Sandra Escoffier; Zheng Li; Luc Thorel
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 6: Onshore and offshore foundation systems
https://doi.org/10.53243/ICPMG2026-126