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Abstract

Open caisson shafts are a widely adopted solution for a range of geotechnical applications. An external ‘cutting shoe’ is a common construction feature used to reduce the soil frictional resistance acting on the caisson during sinking. This forms an annular void encircling the caisson which is filled with a support fluid to maintain excavation stability. The primary aim of this paper is to explore the influence of the cutting shoe geometry on the resulting vertical bearing resistance in sand. Finite element limit analysis is adopted for this purpose. Additional parameters considered in the modelling include the roughness of the cutting face and cutting shoe, and caisson radius and embedment depth. The results show that the influence of the cutting shoe is highly dependent on the caisson cutting face roughness and the soil friction angle, illustrated using detailed soil failure mechanisms. The roughness of the cutting shoe is also shown to cause a significant increase in the vertical soil reaction for large caisson embedment depths. By way of example, a recent UK case study, involving the construction of a 32 m diameter caisson, is used to highlight the potential influence of the cutting shoe on the bearing resistance during caisson sinking.

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Book
Fundamental conceptionsAssumptions involved in the theories of consolidationDifferential equation of the process of consolidation of horizontal beds of ideal clayThermodynamic analogue to the process of consolidationExcess hydrostatic pressures during consolidationSettlement due to consolidationApproximate methods of solving consolidation problemsConsolidation during and after gradual load applicationEffect of gas content of the clay on the rate of consolidationTwo- and three-dimensional processes of consolidation
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Investigation of Soil-Structure Interaction for Large Diameter Caissons
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