Effect of Gapping on the Transient and Sustained Uplift Capacity of a Shallow Skirted Foundation in Clay

Experimental investigation of reverse end bearing of offshore shallow foundations

“…The effect of a gap on uplift resistance of a skirted foundation with embedment ratio d/D = 0.3 in lightly over consolidated kaolin was studied through centrifuge modelling by Acosta-Martinez et al (2010). Two undrained uplift tests were carried out -one immediately after the generation of a gap and another after a significant waiting period, corresponding to ~ 50 -70 % of full primary consolidation according to numerical predictions .…”

Numerical Investigation of the Undrained Compression and Pull-Out Capacity of Suction Foundations in Clay

“…Fig. 5 presented the statistic datas from a range of centrifuge tests [10,11,15,16] and 1g tests [17][18][19][20]. The ultimate displacements are not more than 0.1D and 0.2D when the embedment ratios less than 1 and 2.…”

A novel technique to mitigate the effect of gapping on the uplift capacity of offshore shallow foundations

“…Each of these issues have been addressed by previous research projects, results of which have provided increased confidence in relying on reverse end bearing for transient and limited sustained uplift (e.g. Gourvenec et al, 2009;Mana et al, 2012a) but caution over the effect of gapping -which can jeopardise the sustainability of reverse end bearing (Acosta-Martinez et al, 2010;Mana et al, 2012c). Experimental studies comparing the uplift response of skirted foundations with an intact and gapped skirtsoil interface have shown that, while full reverse end bearing can be mobilised with a sealed foundation with an intact skirt-soil interface, undrained uplift capacity is severely affected by loss of suction at small foundation displacements in the case of a gapped interface (Acosta-Martinez et al, 2010;Mana et al, 2012b).…”

“…Gourvenec et al, 2009;Mana et al, 2012a) but caution over the effect of gapping -which can jeopardise the sustainability of reverse end bearing (Acosta-Martinez et al, 2010;Mana et al, 2012c). Experimental studies comparing the uplift response of skirted foundations with an intact and gapped skirtsoil interface have shown that, while full reverse end bearing can be mobilised with a sealed foundation with an intact skirt-soil interface, undrained uplift capacity is severely affected by loss of suction at small foundation displacements in the case of a gapped interface (Acosta-Martinez et al, 2010;Mana et al, 2012b). Under sustained loading, the rate of displacement can be doubled and the threshold foundation displacement before loss of suction can be halved due to the presence of a gap (Acosta-Martinez et al, 2010;Mana et al, 2012b).…”

“…Experimental studies comparing the uplift response of skirted foundations with an intact and gapped skirtsoil interface have shown that, while full reverse end bearing can be mobilised with a sealed foundation with an intact skirt-soil interface, undrained uplift capacity is severely affected by loss of suction at small foundation displacements in the case of a gapped interface (Acosta-Martinez et al, 2010;Mana et al, 2012b). Under sustained loading, the rate of displacement can be doubled and the threshold foundation displacement before loss of suction can be halved due to the presence of a gap (Acosta-Martinez et al, 2010;Mana et al, 2012b). There is clearly potential benefit from mitigating the development of a gap along the skirt-soil interface or mitigating the effect of a gap should one form.…”