Numerical simulation of the pile integrity test on defected pilesĆosić, Mladen (Avtor) Folić, Boris (Avtor) Folić, Radomir (Avtor) , Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru (Lastnik avtorskih pravic) reflectogram surfacenumerical pile modelsolid finite elementsThis paper deals with the development of a discrete numerical 2D and 3D solid pile model with a discontinuity and defects to simulate non-destructive testing using the pile integrity test (PIT). The pile discontinuity and defects were modelled by reducing the specific finite elements and the elastic modulus of concrete. The wave-propagation response of the pile was analyzed based on a step-by-step numerical integration using the Hilber-Hughes-Taylor (HHT) method in the time domain. The concept of a system-response analysis was originally formulated based on the integration of individual reflectograms into a reflectogram surface, which is generated in a 3D cylindrical coordinate system. The use of reflectogram surfaces enables an understanding of wave propagation based on their velocity to a higher level than is usually the case with standard, one-dimensional reflectograms. Changes in the velocity responses on the reflectogram, shifting from a positive to a negative value, point to the locations of discontinuities and defects in the discrete 3D pile model, and there is a clear difference in the reflectograms, depending on the position of the measuring point. The study defines the typological models of the reflectogram: without discontinuities and defects, pile-head defect, defect in the middle of the pile length or a reduced modulus of elasticity in the middle of the pile length, pile-base defect or reduced modulus of elasticity in the pile-base zone and reduced modulus of elasticity in the pile-head zone.20142018-06-14 11:49:43Znanstveno delo70819ISSN: 1854-0171UDK: 624.131.35OceCobissID: 215987712COBISS_ID: 281008384ISSN pri članku: 1854-0171NUK URN: URN:SI:UM:DK:1ETJPQFAslFakulteta za gradbeništvo, prometno inženirstvo in arhitekturo Univerze v Mariboru