Leveraging Advances in Passive Seismic Methods for Improved Ground Risk Management from Project Planning to Construction

Characterization of subsurface conditions in geotechnical engineering practice relies primarily on intrusive explorations with relatively limited use of geophysical methods. However, intrusive explorations represent merely a point on a map, and the geo-data obtained are interpolated, often across large distances to develop subsurface models for engineering analyses. When used, geophysical methods are limited to downhole geophysics and occasionally 2D methods like Multichannel Analyses of Surface Waves (MASW). This approach to site characterization cannot appropriately capture the actual variability in subsurface conditions. The resulting uncertainty translates in over-design to overcome the insufficient characterization and/or unforeseen conditions during construction, both adversely impacting projects in terms of higher costs and schedule overruns. This study proposes a hybrid approach to site characterization which incorporates geophysics-based initial site screening coupled with conventional intrusive explorations to provide an improved site characterization. The feasibility of the approach is demonstrated through the first in the USA case study. Benefits include more reliable site characterization and improved ground-risk management, translating into more efficient, better performing projects across the entire project life cycle.