An Experimental Investigation Into the Pull-Out Capacity of Suction Caissons in Sand

Abstract

The pull-out performance of conventional suction caissons (with upright walls) has been previously investigated by a number of researchers. However, less attention has been formerly paid to tapered suction caissons. This paper reports some results from an experimental investigation into the pull-out performance of tapered suction caissons. The 1g experiments have been carried out on eight small scale suction caissons. Four specimens have had upright walls while the other four had a positive wall slope of 10%. The caissons have been installed in a soil tank containing very fine saturated silty sand. The caissons have then been subjected to vertical pull-out loads with different speeds. The effects of variations in soil density and pull-out rate on the pull-out capacities have also been investigated. In general, tapered caissons have been noticed to present enhanced pull-out capacities as compared to those from their equivalent upright caissons. The enhancement rate has been found to be more significant in suction caissons with higher aspect ratios. With both upright and tapered caissons the pull-out capacity increases by an increase in the pull-out rate. The pull-out rate effects are more significant with upright caissons in comparison to the corresponding tapered caissons. The density effects, however, are more significant with tapered caissons as compared to their equivalent upright caissons.

Experimental Investigation of Skirted Foundation in Sand Subjected to Rapid Uplift

“…However, the uplift capacity-displacement curve and the suction-displacement curve exhibited similar shapes in all tests. Analogous changes in uplift resistance and suction during pullout were also observed in experiments with lower displacement rates (see Kakasoltani et al (2011) and Wang et al (2019)). Therefore, it can be concluded that the displacement rate has a small effect on the stress-displacement relationship of the skirted foundation, but significantly affects the magnitude of uplift capacity as well as the magnitude of suction in the skirt compartment.…”

“…1. Suction generation between the top plate of the skirted foundation and the soil plug confined by the skirts Kelly et al (2004), Luke et al (2005), Kakasoltani et al (2011), Hung et al (2017), Zhai and Li (2017), and Xie et al (2020).…”