The path, which is on marginally stable, steep shoreline slopes immediately adjacent to SR-28, was constructed largely on bridges and extensively utilized soil nail retaining walls to minimize site impacts in the environmentally sensitive Lake Tahoe Basin.  In addition to significant environmental challenges, the project involved a substantial seismic hazard and difficult access for construction and geotechnical explorations.  These challenges, in part, led to the owner (NDOT) electing to deliver the projecting utilizing the construction manager general contractor (CM/GC) process.

Shannon & Wilson performed project scoping in 2013, which included preliminary alignment feasibility evaluations.  In 2016, Shannon & Wilson began providing geotechnical support for final design of Phases 1 and 2 of the project.  Our scope of services for final design included competing a field reconnaissance, over 30 borings along the project alignment, infiltration testing, and geophysical testing.  Based on information developed from the subsurface exploration program, we developed geotechnical design recommendations for six bridges, several cantilever retaining walls, a box culvert beneath SR-28, MSE retaining walls, rockfall mitigation, and steepened reinforced slopes.  Shannon & Wilson also developed plans and specifications for nine soil nail walls.  

In addition to providing design services, Shannon & Wilson remained involved during construction, providing construction-phase support to the owner and design team.  Our construction-phase services included submittal and shop drawing review, evaluation of micropile and soil nail load tests, site visits, and responding to contractor RFIs.