Pile driving monitoring service

DESIGN, TESTING, INSTALLATION AND OPERATION OF PILE DRIVING MONITORING SYSTEMS

Pile driving monitoring is critical to ensuring that piles are driven into the seabed in accordance with the pile design. We integrate positioning and monitoring workscopes to optimise pile driving operations in line with the required tolerances. 

PDM is a method widely used in offshore construction works to ensure the structural integrity of the piles during driving, driving system efficiency and to derive soil resistance to driving and pile bearing capacity. PDM is a real time testing, not affecting construction time scales. 

PDM measured parameters are acceleration and strain of the energy wave travelling downwards and upwards through the pile. As the strain is elastic, the stress can be calculated by Hook’s law formula and the force in the pile material derived since the pile geometry is known. Velocity and displacement obtained by integration and double integration of the measured acceleration. The transmitted energy derived by integrating of product force and velocity over time. Reflected energy wave used to determine the soil resistance to driving and the pile integrity. Pile axial capacity provided on-line by case method. The most accurate pile capacity delivered in a few hours after completion of driving by CAPWAP signal matching method.  

Massive cost savings achieved by reducing pile design conservatism. Pile capacity calculated based on soil stratification and mechanical properties shall be 3.0-3.5 (FoS) times greater than the applied load. While pile capacity confirmed by Dynamic Testing enable to use FoS of 1.9 (according to PDCA, 2001). It is not necessary to test all the piles in the same ground conditions, PDCA suggests that testing 10% of piles is sufficient. Numerous studies proved accuracy of dynamic pile testing is as close as 1% to 15% to static pile testing.