ABSTRACT
A discontinuum numerical model, using 3DEC, was built to study the behavior of a single reinforced block under seismic load. Block geometry was simplified into a pyramidal shape, varying between 65 and 162 tons, and supported with up to 9 bolts. Seismic signals were taken from a synthetic earthquake with two exceedance frequencies (i.e., expected occurrence) of 1E-6 and 1E-7. These were provided in paper copies and the treatment of the accelerograms consisted of digitizing and cleaning the data, reducing earthquake duration, high frequency filtering, and baseline corrections. Good agreement between initial and processed data was achieved, reducing computation time significantly. Sensitivity analyses showed that joint friction angle had a distinctive threshold for exceedance frequency 1E-6, and that block size was very crucial for 1E-7. Block stability was found to be dependent on a combination of support elements during the earthquake, with shotcrete being essential for block stability.
