DYNAMIC RESPONSE OF SOIL-PILES-MATTRESS-SLAB AND SOIL-PILES-SLAB SYSTEMS UNDER SEISMIC LOADING

Yassamina Neghmouche ； Salah Messioud ； Daniel Dias

《Journal of GeoEngineering》 17卷2期 (2022/06) Pp. 89-101

https://doi.org/10.6310/jog.202206_17(2).3

摘要

This paper presents the dynamic response of soil-piles-mattress-slab and soil-piles-slab systems under seismic loading. In this context, a three-dimensional numerical model using finite elements is proposed; the piles of two systems are embedded in a soft soil. The reinforced soil is surmounted by a load-transfer mattress setup at the rigid piles head level. The piles are embedded in the soft soil and are perfectly connected to a 0.6 m thick slab. The soil-piles-mattress-slab and soil-piles-slab systems are subjected to a horizontal seismic loading. The soil and the mattress are modeled by volume elements, the rigid piles and piles are modeled by beam elements and the slab is by structural elements. The formulation is based on the direct method and the calculations are done considering elastic and elasto-plastic behaviors for the soil mass. The obtained results are compared in terms of horizontal displacements and internal stresses according to the piles length. The obtained results show the effectiveness of the soil-piles-mattress-slab system, the load transfer mattress constituted an energy dissipation zone for the two behaviors. The embedding at the head of the piles induces very high shear forces and bending moments at the level of the pile-structure connection. These efforts could damage the structure. The soil-piles-mattress-slab system eliminates these major efforts at the head of the rigid piles by separating the structure with a mattress. The non-linearity of the ground must be taken into account for further study.

關鍵字

Soil-structure interaction ； piles ； mattress ； dynamic response