Geotechnical investigation and testing - Testing of geotechnical structures - Part 4: Testing of piles: dynamic load testing (ISO 22477-4:2018)
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.