The OC Bridge Program has completed two of seven over/undercrossings to separate street traffic from the more than 70 freight and commuter trains that travel the Orangethorpe Corridor – every day.
The Leighton Solution.
Leighton performed a conceptual geotechnical investigation and subsequent geotechnical exploration to evaluate the geologic, soils, and seismic conditions for the Kraemer Grade Separation. Our design recommendations included a cast-in-drilled-hole (CIDH) pile foundation system for the proposed grade separation, a solution that limited impacts to adjacent property as well as improve constructability and reduce construction costs. The tracks were very close to a two –lane road and housing.
One potential area of concern was liquefaction. To evaluate the liquefaction potential at the site, Leighton’s recommendations also included periodic groundwater monitoring. Although in an area with relatively shallow groundwater, the groundwater monitoring well has remained dry.