A blast modeling system may generate a site model based on blast input data. The blast input data may include blasthole data, bench information, and geology input data. The site model may comprise a plurality of distinct elements representing rock masses. The blast modeling system may simulate a blast by determine initial pressures in each blasthole caused by a detonation of an explosive. The blast modeling system may determine a heave of the blast based in part on the initial pressures, and display a simulation that is based in part on the heave.