A dynamic, two-dimensional, stability analysis of a highly discontinuous rock slope is demonstrated in this paper. The studied rock slope is the upper terrace of King Herod's Palace in Masada, situated on the western margins of the seismically active Dead Sea Rift. The slope consists of sub-horizontally bedded and sub-vertically jointed, stiff, dolomite blocks. The dynamic deformation of the slope is calculated using a fully dynamic version of DDA in which time-dependent acceleration is used as input. The analytically determined failure modes of critical keyblocks in the jointed rock slope are clearly predicted by DDA at the end of the dynamic calculation. It is found however that for realistic displacement estimates some amount of energy dissipation must be introduced into the otherwise fully elastic, un-damped, DDA formulation. Comparison of predicted damage with actual slope performance over a historic time span of 2000 years allows us to conclude that introduction of 2% kinetic damping should suffice for realistic damage predictions. This conclusion is in agreement with recent results of Tsesarsky et al. (In: Y.H. Hatzor (Ed.), Stability of Rock Structures: Proceedings of the Fifth International Conference of Analysis of Discontinuous Deformation, Balkema Publishers, Lisse, 2002, pp. 195-203) who compared displacements of a single block on an inclined plane subjected to dynamic loading obtained by DDA and by shaking table experiments. Using dynamic DDA it is shown that introduction of a simple rock bolting pattern completely stabilizes the slope.
|Number of pages||20|
|Journal||International Journal of Rock Mechanics and Minings Sciences|
|State||Published - Jul 2004|
Bibliographical noteFunding Information:
This research was funded by Israel Nature and Parks authority and partially by the US–Israel Bi-national Science Foundation (BSF) through grant 98-399. The support of the two agencies is hereby acknowledged. Dr. Gen-Hua Shi is thanked for making his dynamic DDA code available for this study. M. Tsesarsky is thanked for collecting and synthesizing structural data in the field and for assistance with direct shear tests. Dr. V. Palchik is thanked for digitizing the structural trace map of the upper terrace. Dr. Guy Stiebel is thanked for guiding us on Masada with archeological insights and for providing the 1924 aerial photographs. Finally, Professor Hudson and two anonymous reviewers are thanked for their critical reading of the manuscript and for their thoughtful comments.
- Earthquake engineering
- Rock slope stability
- Site response
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology