CONTACT & LOCATIONS NEWS MARKETS SERVICES PROJECTS ABOUT CAREERS PROJECTS Mobile Mud Spring Mitigation CLIENT Union Pacific Railroad LOCATION Imperial County, CA In 2016, an unprecedented gas-driven “mud spring” near the southern end of the San Andreas Fault began moving southwest towards the UPRR tracks. The mobile mud spring appeared to be moving along a fault or crack with the gas source at least 2,000 feet below the ground surface. As the gas encounters groundwater, the pressurized gas and water are pushed to surface. The mud spring fluidized the sediment and carved an approximately 75-foot wide and 25-foot deep channel which filled with a mud slurry discharge. Moving in a relatively straight line at a rate of about 10 feet per month, the mud spring remained a discrete, point-like structure. To our knowledge, the behavior of this mobile mud spring is unprecedented. The UPRR retained Shannon and Wilson in May 2018 to evaluate the mobile mud spring (about 80 feet from the tracks) and develop options to mitigate the threat. Our geotechnical services included geophysical surveys, subsurface explorations, relief wells, and construction of a sheet pile wall. Our efforts focused on maintaining railroad operations while attempting to understand and affect the mud spring movement. We contained the mobile mud spring behind a sheet pile wall for about four months. During this time, UPRR constructed a shoofly track on the far side of their right of way from the mud spring and commissioned relief wells in an attempt to depressurize the gas feeding the mud spring. However, in October 2018, the mobile mud spring passed below the sheet piles and emerged in the main line tracks. In less than 12 hours, UPRR diverted train traffic to the new shoofly track and constructed a second shoofly track behind the mud spring’s path. During the summer of 2019, UPRR placed rip rap behind the mud spring as the mud spring continued on its southwest journey through the UPRR right of way. The UPRR plans on restoring the main line tracks over the rip rap backfill once the mud spring is beyond the right of way. The unique mobile mud spring has been featured in the Los Angeles Times, National Geographic, and ASCE Civil Engineering magazine. The mechanisms driving the mobile mud spring are currently being studied by NASA, the Jet Propulsion Laboratory, and several universities. MARKETS SERVED Transportation Rail SERVICES PROVIDED Laboratory Geotechnical Engineering Geologic Hazards Construction Management OFFICE Los Angeles KEY PERSONNEL Jim Bailey Senior Associate, National Well Services Director Elizabeth Barnett Senior Geologist Brian Clements Geology Staff R. Travis Deane Vice President Dean Francuch Senior Associate Stuart Mayes Engineering Geologist Neal McCulloch Vice President, Director of Railroad Services Sean Wilson Senior Engineering Geologist Carolina Zamora Geology Staff MORE PROJECTS SR 520 Floating Bridge And Landings Project Highways/Roads Transportation READ MORE Beacon Hill Link Light Rail Project Transit Rail READ MORE Beartooth Highway Emergency Repairs Transportation Highways/Roads READ MORE Cleveland Innerbelt Transportation Highways/Roads READ MORE MARKETS Transportation Water Property Development Industrial Federal SERVICES Geotechnical Engineering Contamination / Remediation Geologic Hazards Natural Resources Water Resources Design-Build Tunneling / Underground Arctic Engineering Construction Management Specialty Services ABOUT The Company People Corporate Responsibility/Scholarships CONTACT & LOCATIONS Seattle Anchorage Chicago Denver Fairbanks Jacksonville Los Angeles Madison Portland Sacramento Salt Lake City St. Louis Tri-Cities PROJECTS Explore CAREERS Working At Shannon & Wilson CONTACT & LOCATIONS NEWS CLIENT PORTAL © 2021 SHANNON & WILSON, INC. SEATTLE WEBSITE DESIGN