Geohazard Characterization
Geohazard characterization is an essential practice to understand both natural and or anthropogenic geologic conditions that have the potential to pose serious danger to people, property and the environment. HGI designs and implements geohazard characterization surveys to assist clients in identifying and efficiently managing subsurface geological hazards including mine subsidence, voids, sinkholes, ground movement, landslides, subsurface erosion, dam seepage, faults, and industrial hazards. We offer a wide range of expertise in geophysical characterization methods and technologies to provide clients with subsurface geohazard assessments that clearly indicate where potential concerns exist. Using the results of the characterization, mitigation strategies and engineering solutions can be developed to protect life, property, and the environment.
HGI has extensive experience providing geohazard characterization services for municipalities, oil & gas, mining, transportation, and other construction and resource related industries.
HGI provides practical geophysical characterization solutions to identify and map subsurface geohazards such as voids and cavities in the subsurface. Performing characterization ahead of drilling or site construction operations can help avoid damage or loss of equipment, and reduce the loss of expensive drilling muds in oil and gas operations, while enhancing safety, minimizing environmental impacts, and protecting property and financial investments.
Example of an electrical resistivity survey results from a geohazard characterization survey.
Geological hazard characterization includes mapping faults and fracture zones ahead of construction to confirm the stability and competency of the site. Geophysical methods such as seismic shear wave testing, including surface based, down borehole, and cross-borehole survey techniques, are typical parts of foundation investigations or seismic response analysis used by HGI. These types of geophysical approaches are critical for any new developments where understanding the load bearing nature of the subsurface, the potential for earthquake hazards, or the existence of karstic formations and sink-holes is of importance. Subsidence caused by subsurface conditions can strike with little or no warning and result in very costly property damage and even loss of life.
Subsurface geohazards can present significant risk for human activities; therefore, mitigating potential danger through geohazard characterization is an important process to protect life and property.
Another area where geohazards present a challenge are anthropogenic or manmade hazards that exist in the subsurface. These may include old or abandoned underground mining areas, oil & gas well fields, or industrial sites such as brownfields. The location and extent of old mine workings are typically not well documented, are often shallow in nature, and may have partially or fully collapsed so as to present a subsurface geohazard. HGI may incorporate GPR, electromagnetic, seismic, or resistivity geophysical methods to locate old or abandoned mine shafts and workings, identify collapsed or backfilled tunnels which are typically weaker than surrounding geologic structures, and delineate the extent of the mine workings. These methods can also be applied to manmade structures that may impede development or impact safety at a site, such as subsurface tunnels, vaults, or storage areas at industrial and brownfield sites.
Multi-channel analysis of surface waves (MASW) survey results over an abandoned mine site.
HGI approaches each geophysical geohazard survey as a unique opportunity, and we typically do not apply the same set of tools and methods to every project. We use a multifaceted approach, often applying multiple geophysical technologies to gain a richer and more complete understanding of your subsurface environment. We have a wide range of methods and skillsets at our disposal, allowing us to provide a tailored survey to each project site.