It is essential on most piling contracts that some form of testing is carried out to ensure pile design assumptions and load bearing capacities are compliant with the specification. It is normally good practice to agree a specified testing regime prior to commencement of the piling works and one that relates to the method of installation, specific geotechnical risk, variability of ground conditions and the local experience of the piling contractor. We are wiling to offer advice and guidance to ensure that the most appropriate and cost effective regime is always adopted for your project.
Our testing is carried out by Independent and Specialist Testing Contractors who are fully conversant with the requirements contained with the ICE Specification for Piling Works and Embedded Retaining Walls.
Static Load Testing
This involves the direct measurement of pile head settlement in the response to a physically applied test load. The test can be carried out to suit loading categories relating to compression, tension and lateral configurations.
The load is normally applied by means of a hydraulic jack acting against a reaction beam which is restrained by an anchorage systems consisting of either piles or a dead weight reaction mass(Kentledge). The specified test load is then applied in a series of increments in accordance with the piling specification. Each incremental load is sustained for a specified period of time or until the rate of pile head movement is less than a nominated value.
The pile settlements and the residual recovery at each increment are plotted and the resultant load-settlement curves are used to assess preliminary design assumptions and confirm performance criteria.
Dynamic Load Testing
High strain dynamic pile testing is performed using the hammer on the piling rig to provide an estimation of load bearing capacity. The test is performed by attaching strain gauges and accelerometers to the top of the pile that are used to record the wave signal imparted during the test blow onto a Pile Driving Analyser.(PDA)
The response from the hammer blow is monitored in terms of the force and velocity of the stress wave. This information is evaluated using both the case and CAPWAP software programmes to estimate the load bearing capacity and can provide further details on pile integrity, pile head settlements, hammer efficiencies and resistance distribution of the toe and the pile shaft.
The pile tests can be carried out during installation or shortly afterwards to give an early estimation of the pile performance and to provide confidence that the piling works can progress as planned. The results are more or less instantaneous and can provide an economic and comprehensive alternative to traditional methods of load testing.