Representative Geo Hazard Projects
Big Tujunga Dam, CA - Rockslide*
GGI Principal Sean Sundermann led a slope stability evaluation and mitigation design for three exposed slopes along the northern and southern access roads to the Big Tujunga Dam. Performed terrestrial lidar scans and slope mapping to delineate fracture surfaces. Numerical rockfall modeling of 100-300+ ft walls to evaluate stability and mitigation design input parameters. Final design included a mixture of passive cable net, catchment basins and high-tension spyder cable at spot locations of high hazard. Developed final design drawings and specifications for the design. Performed bid review for the water district to select rockfall contractor.
Trans Anatolian Natural Gas Pipeline Project*, Turkey - Geohazard Mapping & Mitigation
GGI Principal Sean Sundermann served as the geohazard subject matter expert and led a geohazard mapping program along a 150 km stretch identified as highly susceptible to multiple unique hazards, including large-scale landslides, massive karst features and collapse, and multiple active-fault crossings. While under previous employment, Sean developed a project-specific karst classification scheme to identify hazards and appropriate mitigation at a detailed scale. Developed fault parameters for probabilistic fault displacement hazard analysis. Sean also performed fault characterization paleoseismic trenching at intersections with the North Anatolian faults and several secondary faults along the full length of the pipeline.
Eisenhower Tunnel, CO - Loveland Landslide*
GGI Principal Sean Sundermann served as a subject matter expert for rock mass, geohazards, initial lining and tunnel support as part of the CDOT tunnel inspection team for emergency failure evaluation and repair recommendations on several tunnels over multiple years. Mr. Sundermann participated as the landslide subject-matter expert in evaluating the condition of the recently-active Loveland landslide above the Eisenhower Tunnel.
East Edisto Gas Transmission, SC - Seismic Risk Assessment*
Assessment of potential seismic risks associated with the proposed pipeline to satisfy PHMSA Mega Rule requirements to evaluate outside threats inclusive of seismicity. The evaluation was focused on the pipeline alignment with the Charleston Seismic Zone which is characterized to have Repeated Large-Magnitude Earthquakes. A seismic source model was compiled that includes both area source zones for shallow crustal provinces and fault sources that represent the specific tectonic elements of the region with characteristic earthquake distributions. The assessment also evaluated the strong potential for pipeline damage from liquefaction occurring as lateral flows and induced settlement along the alignment, revieing site-specific geotechnical data and historical liquefaction features.
USGS Fault Mapping, CA - Digital Fault Compilation*
GGI Principal Sean Sundermann has been a Principal Investigator for several digital fault data compilation projects for both the Northern and Southern California Map Database collaborating with the USGS and funded by the NSF. These maps compile geologic data on active fault systems to revise and build upon previous work to define fault-related hazards included in the Quaternary fault map and database.
* Projects prior to GGI