Geotechnical design of tunnels requires a level of precision and accuracy in the determination of subsurface parameters that is more rigorous than most applications of geophysical logs. Misunderstanding of the geo-mechanical and hydraulic properties can slow tunnel construction, increase risk and cost, and in the worst cases, leads to failure of tunneling equipment and excavation support with potential catastrophic results. As such, these projects demand a wealth of measurements of the subsurface by geophysical means. Establishing the nature and condition of ground and groundwater that will impact upon the proposed alignment and associated structures is key. This sometimes can be accomplished by near-surface techniques, but many complex geologies require high resolution borehole measurements to fully understand the setting for intended projects.
The following material from the SAGEEP, 2019, is published with the permission of the Environmental and Engineering Geophysical Society. All copyright privileges remain with EEGS/EAGE. This material cannot be copied or used without the express written permission of EEGS/EAGE.