The Gerald Desmond Bridge is being replaced with California’s first long span, cable-stayed bridge, with an additional 50 feet of clearance, making it one of the tallest cable-stayed bridges in the United States.
A tremendous amount of effort is focused on collecting data about the Earth’s surface using satellites, airplanes, terrestrial mobile mapping units, total stations and many other devices. Even land areas under water are measurable up to a certain depth. It is reasonable to say that we are at the point where nearly everything above ground is mapped.
The slogans “Call before you dig” and “Know what’s below” are familiar reminders of the importance of verifying the location of all kinds of subsurface utility infrastructure before excavation takes place. It only takes a moment for a pipeline or conduit to be damaged by heavy equipment, potentially causing public safety issues and disruption of service; thus the need for subsurface utility engineering (SUE).