San Miguel Widening and Realignment at US 101

This $53M Caltrans highway improvement project rehabilitated an eight-mile stretch of US 101 through the City of San Miguel. The project widened a section of US 101 and reconfigured multiple on- and off-ramps, requiring the project to be constructed in multiple stages, while keeping traffic moving through the work zone. As part of the realignment, the project constructed three new bridges and widened seven bridge undercrossings. Additional project elements included a 750-foot-long soil nail wall and a Type 1 retaining wall; embankments with specified settlement periods; large drainage systems requiring deep excavation and shoring including installation of 48- and 72-inch diameter jack-and-bore welded steel pipes under US 101; miles of k-rail placement; temporary pavement; traffic control; jointed plain concrete pavement (JPCP); and multiple utility relocations.

The highway rehabilitation portion of this project reconstructed areas of US 101 and non-standard on- and off-ramps. The new highway section consisted of lean concrete base and rubberized hot mix asphalt (RHMA) construction. Resurfacing included crack and seat construction as well as the installation of a Stress Absorbing Membrane Interlayer (SAMI). Reconstruction included 16 freeway on- and off-ramps and over 28 drainage systems.

The project provided for beautification with the construction of architectural treatment of the concrete barriers, retaining walls, slope paving, and gore concrete. This project was constructed in accordance with Caltrans standards, methods, and procedures.

MNS provided construction inspection and materials testing services for the highway and structures work, including Resident Engineer and Structure Representative duties. Tasks included daily inspection and documentation of the work and manpower, quantity calculations, traffic control, and materials testing.