In this work, the trapped magnetic field was calculated for square bulk superconductors using the sand-pile model and Biot-Savart law. The numerical simulation of the trapped magnetic field was performed varying the sample dimensions, distance between the sample surface and observation point. In addition the magnetic field characteristics of superconducting bulk arrangement in an array was determined. The trapped magnetic field was found to be depending on the sample dimensions and distance between the sample and observation point. It is observed that, when the distance from the surface is larger, the value of the trapped magnetic field decreases, but the variation of the trapped magnetic field becomes small due to averaging the distribution of the trapped magnetic field. (C) 2010 Elsevier B.V. All rights reserved.