Bridge & Infrastructure Scanning in San Pablo, CA

San Pablo is small enough to walk across and still carries a full set of structure problems, because two creeks and two regional roadways cross it. The San Pablo Avenue bridge over San Pablo Creek at the Road 20 and 23rd Street intersection was built in 1926, has been flagged as structurally deficient, and is the subject of a roughly seventeen million dollar replacement funded largely by the federal Highway Bridge Program through Caltrans Local Assistance, with the intersection realigned as part of the work. Rumrill Boulevard crosses Wildcat Creek a short distance west and is being rebuilt as a complete street. The Richmond Parkway carries its own structures at the city edge, with a multi-use crossing of the Wildcat Creek Trail planned at the Parkway, and Interstate 80 runs the eastern boundary. City and county engineers, the consultants designing those replacements, and contractors documenting conditions before demolition all need the same thing first: measured existing geometry.

Our method on a structure is fixed. We set monuments, observe them with GNSS and total station, adjust the network by least squares on NAD83 State Plane California Zone 3 and NAVD88 with independent check observations, then register every Trimble scan position into that network and report the residuals. The result is millions of survey-grade points describing deck, soffit, girders, bents, abutments, wingwalls, bearings, and joints as they actually stand, plus the channel invert and banks approaching the opening. Vertical clearance is computed across the full width of the travelled way from the soffit surface rather than sampled with a rod, so the controlling low point is found, not guessed. Field time is short, which matters on an arterial where a closure window is measured in hours.

Deliverables include registered E57 or RCP clouds, DWG or DXF plans, sections, and soffit contours, clearance envelope reports, and epoch comparisons for scour or settlement. See infrastructure scanning, San Pablo 3D scanning, and deformation monitoring.