Bridge & Infrastructure Scanning in Moraga, CA

Moraga's structure problems are the ones that hit small towns hardest: a handful of aging bridges and a large buried drainage system, on ground that moves. The Canyon Road bridge over the West Branch of San Leandro Creek, built in 1936 at roughly 104 feet long and 24 feet wide, carried a sufficiency rating in the forties before the town moved to replace it with a wider clear span under the federal Highway Bridge Program route that Caltrans Local Assistance administers for city-owned structures. Underground, the failure mode is corrugated metal pipe: in March 2016 a 96-inch corrugated metal storm drain under the Rheem Boulevard and Center Street intersection lost the soil around it and the roadway collapsed, taking a signal pole and a utility vault with it, and roughly 130 feet of pipe was eventually replaced with reinforced concrete. Across town, the Lafayette-Moraga Regional Trail runs about seven and a half miles on the old Sacramento Northern right-of-way, crossing streets roughly a dozen times and the creek three, mostly parallel to Saint Mary's Road.

We scan that inventory tied to an observed control network: monuments set and measured with GNSS and total station, least-squares adjustment on NAD83 State Plane and NAVD88 with independent checks, every Trimble scan position registered in, and residuals reported. Bridges come back as deck, soffit, girder, abutment, and wingwall geometry with clearance computed across the full width and channel sections at the opening. Culverts come back as interior surfaces where they can be occupied, showing ovality, invert profile, and joint offsets, and as headwall and inlet geometry where they cannot. Retaining walls and the slopes behind them come back as continuous surfaces, and a repeat epoch differenced against the baseline turns suspicion of movement into a measured displacement map.

Deliverables are registered E57 or RCP clouds, DWG or DXF sections and profiles, clearance and ovality reports, and displacement maps. See infrastructure scanning, Moraga 3D scanning, and deformation monitoring.