A field investigation into the mechanisms of pile ageing in sand

The design of axially loaded piles has been an area of focus for the offshore industry in recent years. A number of studies report substantial increases in the shaft capacity of piles driven in sand, known as pile ageing. The offshore industry has been slow to implement ageing into practice because of uncertainty over the mechanisms...

Investigation of Cyclic Loading of Aged Piles in Sand

In recent years, there has been a significant push to develop optimized pile designs in the offshore industry, driven by the growth of offshore wind. One of the largest remaining uncertainties governing axial pile design in sands is the influence of ageing effects and how an aged pile responds under axial cyclic loading. This paper presents...

A review of CPT based axial pile design in the Netherlands

Because of the deltaic nature of the Netherlands, deep soft soil deposits are widespread. Due to the population density exploitation of underground space is vital for commercial developments and transport networks. Piles are used as primary support elements in deep excavations, cut and cover tunnels, quay walls, flood defences and to provide...

Cyclic Laterally Loaded Medium Scale Field Pile Testing for the PISA Project

The PISA project explored the development of improved design methods for offshore wind turbine monopile foundations. Medium scale field pile testing for the project took place at Cowden in the UK, where the soil consists of a heavily over-consolidated glacial till, and Dunkirk in France, where the soil consists of a dense marine sand. The main...

PISA design model for monopiles for offshore wind turbines: Application to a stiff glacial clay till

Offshore wind turbines in shallow coastal waters are typically supported on monopile foundations. Although three-dimensional (3D) finite-element methods are available for the design of monopiles in this context, much of the routine design work is currently conducted using simplified one-dimensional (1D) models based on the p-y method. The p-y...

Ground characterisation for PISA pile testing and analysis

This paper is the first of a set of linked publications on the PISA Joint Industry Research Project, which was concerned with the development of improved design methods for monopile foundations in offshore wind applications. PISA involved large-scale pile tests in overconsolidated glacial till at Cowden, north-east England, and in dense,...

Monotonic laterally loaded pile testing in a stiff glacial clay till at Cowden

This paper describes the results obtained from a field testing campaign on laterally loaded monopiles conducted at Cowden, UK, where the soil consists principally of a heavily overconsolidated glacial till. These tests formed part of the PISA project on the development of improved design methods for monopile foundations for offshore wind...

Monotonic laterally loaded pile testing in a dense marine sand at Dunkirk

The results obtained from a field testing campaign on laterally loaded monopiles, conducted at a dense sand site in Dunkirk, northern France are described. These tests formed part of the PISA project on the development of improved design methods for monopile foundations for offshore wind turbines. Results obtained from monotonic loading tests...

PISA design model for monopiles for offshore wind turbines: Application to a marine sand

This paper describes a one-dimensional (1D) computational model for the analysis and design of laterally loaded monopile foundations for offshore wind turbine applications. The model represents the monopile as an embedded beam and specially formulated functions, referred to as soil reaction curves, are employed to represent the various...

New data analysis methods for instrumented medium-scale monopile field tests

The PISA Joint Industry Research Project was concerned with the development of improved design methods for monopile foundations in offshore wind applications. PISA involved large-scale pile tests in overconsolidated glacial till at Cowden, north-east England, and in dense, normally consolidated marine sand at Dunkirk, northern France. This...

3D FEM approach for laterally loaded monopile design

Over the past 5 years, a substantial research effort aimed at optimising the design of offshore wind turbines has led to significant reductions in the projected cost of developing offshore wind. Optimising the geotechnical design of these structures, through modern analysis techniques such as 3D Finite Element Modelling (FEM), has played a...

Research and Development Activities on Pile Foundations in Europe

The paper describes some recent field test programmes performed across Europe. Given the increased need to develop alternative, clean energy sources the paper presents details of R&D programmes with a focus on reducing costs offshore developments and increases safety. Work on the development of design codes for large diameter piles is...