Bridge & Infrastructure Scanning in Richmond, CA

Richmond holds the heaviest inventory of structures in West Contra Costa County. The Richmond-San Rafael Bridge, formally the John F. McCarthy Memorial Bridge, opened in 1956 and carries Interstate 580 across the bay on 5.5 miles of double-deck cantilever and truss with a long trestle approach off the Richmond shoreline; its trestle, fenders, and deck were rehabilitated in 2006. Inland, the I-80 and I-580 interchange and the Richmond Parkway, a 7.5-mile arterial completed in 2001 to link the bridge to I-80, carry the freight route through the city on a run of grade separations and overheads. The Dornan Drive tunnel, bored through Nicholl Knob in 1912 and once called the Ferry Point tunnel, runs about 740 feet between Point Richmond and the shoreline. Add the BNSF and Union Pacific bridges around the yard, the Port's wharves, the ferry terminal, and the refinery pipe racks and trestles along the waterfront.

Each of those asks the scanner a different question, and all of them share a method. We observe a control network with GNSS and total station, adjust it by least squares with independent checks on NAD83 State Plane and NAVD88, and register every scan position to it, so the deliverable carries coordinates rather than internal consistency. From it come vertical and horizontal clearance across full travelled width and along a tunnel bore, structural as-builts of trusses, girders, bents, bearings, joints, abutments, and fender systems for seismic retrofit and load rating, wharf deck and pile-cap surfaces, tank and pipe-rack geometry, and scour or settlement baselines that later epochs are differenced against surface to surface. Because scanning is non-contact and each position takes minutes, congested, elevated, and over-water geometry is reached without rope access, scaffolding, or a second closure.

Deliverables are registered E57 or RCP clouds, clearance envelopes and diagrams, DWG or DXF sections, elevations, and framing plans, surface and mesh models, epoch comparison exhibits, and stamped products where a licensed deliverable is required. City-owned bridges funded through the federal Highway Bridge Program and Caltrans Local Assistance carry documentation expectations we scope to. See infrastructure scanning, Richmond 3D scanning, and deformation monitoring.