Bridge & Infrastructure Scanning in Orinda, CA

Orinda's structures are unusually varied for a city of its size. State Route 24 enters through the Caldecott Tunnel, four bores through the Berkeley Hills whose fourth bore opened in 2013 at roughly 3,400 feet, and BART runs in the highway median before diverging into the Berkeley Hills Tunnel with its portal on the Orinda side. Camino Pablo, the Orinda end of the twelve-mile county arterial signed San Pablo Dam Road, meets the highway here. Beneath the East Bay Municipal Utility District's Orinda water treatment plant, the Claremont Tunnel carries treated water more than three miles to Berkeley across the Hayward Fault and was seismically upgraded between 2004 and 2007. And the city's own inventory is the one that fails first: in January 2017 a century-old 72-inch corrugated metal culvert under Miner Road at Lauterwasser Creek collapsed into a sinkhole about 25 feet across and 20 feet deep, and was replaced with a 7.5 by 16 foot box culvert and retaining walls before the road reopened that July.

All of it is scan work, and all of it is control work first. We set and observe monuments with GNSS and total station, adjust the network by least squares on NAD83 State Plane and NAVD88 with independent checks, register each Trimble scan position into it, and report residuals. Tunnel and culvert interiors come back as continuous surfaces, so ovality, lining thickness change, invert profile, and clearance envelope are computed rather than sampled. Road structures come back as wall face and batter profiles, headwall and wingwall geometry, and bare-earth ground beneath the oaks. Where slow movement in the local formations is the concern, a repeat epoch differenced against the baseline reports displacement across the whole surface.

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