Experimental observation on laterally loaded pile in unsaturated silty soil

Abstract

An experimental study has been carried out to investigate the effects of soil partial saturation on the behaviour of laterally loaded piles. The proposed study has been conducted by means of centrifuge tests at 100×g, where a single vertical pile has been subjected to a combination of static horizontal load and bending moment. The study has been conducted on a silty soil characterized with laboratory testing under saturated and unsaturated conditions. During flight, two different positions of water table have been explored. The influence of density has been investigated compacting the sample with two different void ratio. Finally, the effects of a variation of saturation degree on the pile response under loading have been studied rising the water table to ground surface. Data interpretation allows drawing different considerations on the effects of partial saturation on the behaviour of laterally loaded piles. As expected, compared to saturated soils, partial saturation leads always to a stiffer and resistant response of the system. However, the depth of the maximum bending moment is related to the position of water table and the bounding effects induced by partial saturation appears to be more important for loose soils.

Numerical modelling of the response of an unsaturated silty soil under wetting and gravitational loading processes

“…This paper presents some results of a parametric numerical study devised to reproduce the centrifuge tests carried out by Lalicata et al [1] on a laterally loaded pile. The attention is focused only on the first two phases, during which the soil model is subjected to an imbibition process at 1xg and, then, to an increase in the gravity loading up to 100xg.…”

“…The experimental study was conducted by Lalicata et al [1] using the geotechnical centrifuge of IFSTTAR in Nantes. The material used is the commercial B-Grade kaolin consisting of 90% silt and 10% clay.…”

“…In many situations, however, natural soils are found in a state of partial saturation as the groundwater table is at a great depth. The experimental study conducted by Lalicata et al [1] aimed at assessing the influence of partial saturation on the response of laterally loaded piles installed in fine-grained soils. The centrifuge tests were performed on loose and dense soils under fully and partially saturated conditions.…”

Numerical analysis of wetting‐induced instabilities in partially saturated soils under plane strain conditions

“…The onset of these hydraulically induced instabilities can be predicted by using the same abovementioned approaches extended to unsaturated conditions . These phenomena play a crucial role either in triggering shallow landslides or in the development of displacements of foundations and earthworks . As a consequence, in the last years, major efforts have been made to both better understand the related activation mechanisms and define reliable theoretical and numerical tools of analysis.…”

“…[15][16][17] These phenomena play a crucial role either in triggering shallow landslides [18][19][20] or in the development of displacements of foundations and earthworks. [21][22][23] As a consequence, in the last years, major efforts have been made to both better understand the related activation mechanisms and define reliable theoretical and numerical tools of analysis. This paper approaches hydro-mechanical instabilities occurring in partially saturated soils due to rainfall events.…”