ISO 22477-4:2018 establishes the specifications for the execution of dynamic load tests in which a single pile is subject to an axial dynamic load in compression.ISO 22477-4:2018 outlines the methods of testing required to allow assessment of pile resistance to be determined from the following methods and procedures described in EN1997-1:2004+A1:2013:a) dynamic impact testing - determination of pile compressive resistance by evaluation of measurements of strain and acceleration and or displacement at the pile head with respect to time;b) pile driving formulae - evaluation of pile compressive resistance from blow counts and hammer energy during pile driving;c) wave equation analysis - evaluation of pile compressive resistance from blow counts by modelling of the pile, soil and driving equipment;d) multi-blow dynamic testing - evaluation of pile compressive resistance from a series of blows designed to generate different levels of pile head displacement and velocity.ISO 22477-4:2018 is applicable to piles loaded axially in compression.ISO 22477-4:2018 is applicable to all pile types mentioned in EN 1536, EN 12699 and EN 14199.The tests considered in this document are limited to dynamic load tests on piles only.NOTE 1 ISO 22477-4 can be used in conjunction with EN1997-1:2004+A1:2013. Numerical values of partial factors for limit states from pile load tests to be taken into account in design are provided in EN 1997-1. For design to EN 1997-1 the results from dynamic load tests will be considered equivalent to the measured compressive resistance Rc,m after being subject to appropriate analysis.NOTE 2 Guidance on analysis procedures for dynamic load testing results is given in Annexes A, B, D, E and F.ISO 22477-4:2018 provides specifications for:i) investigation tests, whereby a sacrificial pile is loaded up to ultimate limit state;ii) control tests, whereby the pile is loaded up to a specified load in excess of the serviceability limit state.NOTE 3 Generally, an investigation test focuses on general knowledge of a pile type; a control test focuses on one specific application of a pile.