Consolidation effects on uplift capacity of shallow horizontal plate anchors in dilating sand. Issue 12 (18th October 2021)

• Record Type: Journal Article
• Authors: Roy, Anamitra; Chow, Shiao Huey; Randolph, Mark F.; O'Loughlin, Conleth D.
• Is Part Of: Géotechnique. Volume 71:Issue 12(2021)
• Page Start: 1
• Page End: 17
• Publication Date: 2021-10-18
• Subjects: bounding surface model -- cavitation -- coastal, marine and offshore geotechnics -- consolidation -- foundations and soil-structure interaction -- numerical modelling -- physical modelling -- plate anchors -- sand; Soil mechanics -- Periodicals; Engineering geology -- Periodicals; Geotechnical engineering -- Periodicals; 624.151
• DOI: 10.1680/jgeot.20.P.117
• Languages: English
• ISSNs: 0016-8505

Abstract

Abstract : This paper examines the effect of consolidation on a shallowly embedded horizontal plate anchor in medium dense and dense sand using centrifuge tests, where the loading rate was varied over four orders of magnitude. The experimental results show a 4·8 to 5·5 times increase in anchor capacity as the consolidation condition changes from drained to undrained, driven by a steadily increasing negative excess pore pressure with increasing loading rate. At the highest loading rate, under undrained conditions, the measured maximum negative excess pore pressures reach a steady limit, suggesting the occurrence of cavitation. This increase in anchor capacity with dimensionless velocity is captured using a 'backbone curve' interpretation framework that describes the change in capacity between the limiting values of drained and undrained anchor capacity. Calculation of drained anchor capacity is straightforward relative to the more challenging problem of calculating undrained capacity, particularly during cavitation. This was addressed separately through a numerical parametric study (pure undrained analysis) using a bounding surface soil model involving different water depths (cavitation potential), densities and embedment ratios. The numerical results are then synthesised into a simple extended analytical solution to allow estimation of undrained anchor capacity under different densities and water depths.