The Ongoing Challenge of Rail Line Stability
The Orange County Register recently reported on the persistent challenges facing the LOSSAN Rail Corridor, as landslides and coastal erosion threaten rail operations in Southern California. Since 2021, this vital transportation corridor has experienced multiple disruptions due to bluff failures and shrinking beaches, triggering emergency interventions and long-term stabilization efforts.
At GMU, we are deeply familiar with the geotechnical complexities of this issue. Our recently published white paper, "Coastal Erosion Induced Landslide in South Orange County," authored by Katie Farrington, Greg Silver, and Ashley Varni, highlights a case study that mirrors the very challenges outlined in the OC Register article. Our study documents how the loss of sand buttressing at the toe of a landslide led to reactivation, resulting in structural damage, utility disruption, and even rail line deformation.
The Science Behind the Landslide Threat
As documented in our research, beach sand plays a critical role in stabilizing coastal slopes. Over time, natural erosion and human-driven changes—such as coastal armoring, storm surges, and sediment transport reduction—have stripped away these natural buttresses. The result? There is a higher probability of slope failures that directly impact rail infrastructure.
Our findings confirm that without intervention, further sand depletion and erosion could continue to destabilize bluffs, leading to costly disruptions, increased emergency repair needs, and potential safety risks for passengers and freight operations.
GMU’s Expertise in Coastal Landslide Mitigation
GMU has been at the forefront of geotechnical engineering solutions to stabilize slopes and protect infrastructure for decades.
Our approach to landslide mitigation and rail corridor stability includes:
✅ Subsurface Investigations – Identifying failure mechanisms and risk factors through advanced geotechnical assessments.
✅ Slope Stability Modeling & Monitoring – Utilizing inclinometers, piezometers, and real-time data to track movement and predict failure risk.
✅ Engineering Solutions – Designing stabilization strategies, including tie-back anchors, riprap placement, and reinforced retaining structures.
✅ Regulatory & Environmental Navigation – Collaborating with agencies to balance infrastructure protection with coastal sustainability.
Moving Toward Sustainable and Effective Solutions
The OCTA’s Coastal Rail Stabilization Priority Project seeks to address these issues through bluff stabilization, riprap reinforcement, and sand replenishment. However, as our research suggests, finding a sufficient and sustainable source of sand is a critical challenge.
“It’s not just about stopping landslides—it’s about understanding the long-term interplay between coastal processes, infrastructure demands, and engineering solutions,” says Katie Farrington, PG, CEG, Senior Engineering Geologist at GMU.
“Our findings emphasize that mitigation efforts must be proactive, multi-faceted, and scientifically driven.”
As OCTA and regional stakeholders refine their strategies, GMU is ready to contribute our geotechnical and coastal engineering expertise to develop solutions that protect rail operations while maintaining the integrity of Southern California’s coastline.
Read More & Engage with Us
Explore our full white paper here: GMU Coastal Erosion Study Join the conversation – How can we balance infrastructure protection with coastal preservation? Comment below!
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