Dynamic Loading Impact on Cement Borehole Seals

Abstract

One of the concerns with regard to the performance of borehole seals is the impact of earthquakes, or other types of dynamic loading such as large-scale blasting, on seal integrity. Of all possible scenarios (erosion, glaciation, tectonic and other natural processes), seismic motions are the most likely effects to be experienced by borehole and excavation seals. In the United States many locations are sufficiently close to seismic regions to be affected thereby (as can be seen from the seismic hazard map shown in Figure 4.1), while sufficiently far not to experience major effects such as rock fall, slippage and/or breakage. The map in Figure 4.1 indicates the effective peak acceleration that might be expected to be exceeded during a 50 year period with a 10% probability.