Test Loading of Piles and New Proof Testing Procedure

A presentation of four current pile test methods is given. It is claimed that when the test is a part of a field investigation or a proof testing, any method can be used. Eight methods of interpreting failure are reviewed and compared, showing a 40% scatter of interpreted failure values for two actual tests. It is proposed that the Slow ML method, commonly used for proof testing, be replaced by a Quick ML method carried to 250% maximum load with a new acceptance criterion consisting of the requirement that the gross movement at 200% load shall be less than the elastic pile compression and an additional value of 0.15 in. plus l/120 of the pile diameter.