The SR 89 Mousehole Pedestrian and Bicycle Improvement Project was a high profile and long awaited project that constructed a multi-use path and pedestrian tunnel along the east side of State Route 89 and Interstate Highway 80. The tunnel was a UPRR underpass that was constructed under UPRR, Caltrans, and FHWA oversight. The new multi-use path is a 10-foot wide concrete surfaced shared-use path that separates and provided safe walking and bicycling from motor vehicle traffic.
4LEAF provided the full range of construction management services including project inspection, quality assurance, materials testing, safety, partnering, claims mitigation and document control for the project. The project was funded with Federal, State, and local sources.
The new underpass (tunnel) is just east of the existing grade separation (Donner Creek Underpass, Bridge Number 17-0016). The tunnel construction required installation of ground freeze piping and freezing the soil on the existing embankment to support Cooper E80 live loads. The scope included construction of a concrete box for jack and bore operations as well as multiple retaining walls. Additional project features included a bus turnout and transit shelter, new hiking trail, and construction of infiltration basin and miscellaneous drainage improvements. The project also relocated a traffic signal.
The project included jack and bore construction methods; construction of 10-ft+ high retaining walls; involvement with UPRR staff; Caltrans and FHWA oversight; and confirming SWPPP controls were installed and maintained. The project also required extensive traffic control measures and required keeping one lane of traffic open at all times during construction. The UPRR rail line also remained operational during construction.
The following link to the video produced by the project’s Contractor provides highlights of the project: https://www.youtube.com/watch?v=fwSGuua62B0