The need for pile testing

Market pressures have resulted in keen competition amongst piling contractors. Together with increased loadings from taller and more complex structures, these market pressures have been a contributory factor to increased loadings on piles. The piling market also demands that time for completion of works be reduced to the absolute minimum. Consequently, the combination of higher loadings and the necessity to complete works to strict time constraints should demand a more comprehensive testing regime to ensure quality. Higher loadings are usually resisted by larger diameter bored piles. Until recently, higher loads could not be tested economically using conventions static testing methods. The introduction of Statnamic and Osterberg-cell testing has changed this. However, the author believes that testing in Australia and also in most Western countries, has not been increased to cater for the newer, more demanding industry needs. Construction methods for bored and auger piles have often been shown to suffer potentially serious deficiencies if quality control measures are not satisfactory. Examples of problems are presented fox CFA piles and bored piles, with the latter also addressing problems observed with the use of bentonite drilling fluids. The need for testing is discussed, with particular emphasis being placed on problems that occur during pile construction. It is concluded that the pile testing regime on a project should be increased to ensure that quality of construction is commensurate with design expectations, and also to enhance understanding of pile behaviour and pile design.