MODIFICATION OF THE DDA METHOD FOR RIGID BLOCK PROBLEMS

This paper presents the development of the rigid block version of disc ontinuous deformation analysis and its preliminary application in rock fall simulation. Modifications, including the reduction of the error d ue to large rigid body rotation by using post-correction at each time step of calculation and the incorporation of mass proportional clampin g to account for. energy losses, are made to meet the requirement for lar ge block translation as well as rotation. To improve the program e fficiency, rigid body displacement function and preconditioned conjuga te gradient solver are adopted. The results obtained show that the new ly developed code, RIG-DDA, can appropriately and efficiently model va rious modes of rockfall movement and predict the trajectory of falling rock debris, which is helpful in the design of protection measures. ( C) 1998 Elsevier Science Ltd.