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The soil arching effect is the key mechanism for load transfer in pile-supported reinforced road (runway) foundations. To investigate the formation and evolution process of soil arching effect in the whole process of embankment filling and soft soil foundation consolidation, a three-dimensional hydro-mechanical coupled numerical model of pre-fabricated high-strength concrete (PHC) pile-reinforced soft soil runway foundation was established based on the foundation treatment project in Pudong Airport. The laws of variation of soil settlement, pore water pressure and pile soil stress were analysed, and the influence of pile spacing was considered. These data from both numerical simulation and field test indicate the soil arching effect in the foundation reinforced by PHC piles and preliminarily reveal the evolution of soil arching in the process of embankment filling and soft soil foundation consolidation. The preliminary results encourage the authors to continue this research to investigate the evolution of soil arching under aircraft dynamic loads through adding a more suitable constitutive model or subroutine in this numerical model. [ABSTRACT FROM AUTHOR]

Dynamic soil stress in the ground induced by aircraft loads can lead to excessive and differential settlements. The effect of aircraft speeds on the dynamic stress is complicated due to runway roughness, lift force and wave propagation. In this paper, a virtual prototype model of B777-300 was initially developed to investigate the aircraft loads impacted by runway roughness and lift force. Subsequently, a finite element model of the runway was established for the dynamic stress in the ground subjected to moving aircraft loads. Results show that as aircraft speed increases, the aircraft-load-induced dynamic stress in the ground first increases and then decreases. The critical speed of dynamic stress accompanied with a peak stress varies with soil depth. In the shallow soil layers, dynamic stress in the ground is mainly affected by runway roughness and lift force. The critical speed of dynamic stress is close to the sensitive speed corresponding to peak aircraft loads. With the increase of soil depth and aircraft speed, the effect of dynamic amplification due to wave propagation becomes more pronounced. In the deep soil layers, the critical speed of dynamic stress approaches the Rayleigh wave velocity of soils, especially when soft soil layers exist. [ABSTRACT FROM AUTHOR]