ENGEO provided preliminary consultation services for a privately funded high-speed rail line from Victorville, California to Las Vegas, Nevada. The proposed project, Xpress West, involved the construction of a fully grade-separated, double-track, passenger-only high-speed railroad. The intent of the consultation was to identify high-level geoengineering design options to facilitate the project’s preliminary design corridor for the environmental impact study. ENGEO’s goal was to address four major concerns; potential geotechnical and engineering geology issues associated with the significant cuts and fills proposed, geologic characterization for tunnel engineering, conceptual mitigation of fault crossings, landslides, settlement or collapse of alluvial deposits, liquefaction, compressible and corrosive soils, and conceptual foundation design for railroad crossing structures, bridges, grade separations, and maintenance support facilities. The project execution required ENGEO compliance with numerous Federal and State biological and environmental protection requirements, including those relating to the Desert Tortoise and sensitive plant species.
During the initial project scoping, ENGEO performed extensive site reconnaissance which greatly assisted in developing conceptual geologic and geotechnical mitigation schemes. Specifically, ENGEO completed a reconnaissance of the proposed tunnel segments (Segment 4) and the proposed tunnel portals at Mountain Pass and Primm. Next, ENGEO performed a preliminary review of Caltrans PS&Es to provide conceptual foundation improvement schemes (such as underpinning) at locations where the rail alignment is planned to utilize existing interstate grade separations.
Additional work involved assessing existing bedrock cuts and at-grade crossings where the alignment would potentially parallel the existing UPRR right-of-way. The purpose was to qualitatively evaluate the existing performance of tall bedrock cut slopes and the potential challenges of developing grade separations at existing intersections. ENGEO then provided preliminary geotechnical exploration and engineering cost estimates required to develop fundamental plans and specifications.
Following those services, ENGEO performed over 100 geotechnical boreholes, test pits, and geophysical tests for the 4,000-acre concentrating solar power generation facility at Ivanpah Valley. XpressWest actually had to be re-configured in Ivanpah Valley due to the plant’s early start.