GeoStru Georock 2D v2018.12.1.456 [Size: 50.7 MB] ... GeoRock 2D is a software made by GeoStru for the 2D simulation of rockfalls using Lumped Mass and C.R.S.P. models. For the Lumped Mass model, the computation assumptions are: plan outline, the slope profile similar to a broken line consisting of straight line segments; point boulder and neglectable air resistance. CRSP (Colorado Rockfall Simulation Program) model has been developed by Pfeiffer and Bowen (1989) with the purpose of modeling the falling motion of boulders having the shape of spheres, cylinders or discs, with circular cross section in the vertical plane of the movement. The reliability of the model was verified by comparisons between numerical results and the results obtained from in situ tests.