Innovative Bridge Foundation Protection in Santa Ana, California-PPT Presentation

PPT Presentation

Pdf Summary

The Santa Ana BNSF Bridge Protection project in Corona, California, involved constructing structural slurry walls to protect the bridge foundations from scour for the U.S. Army Corps of Engineers. The work included 48-inch walls at the east and west abutments, reaching depths of up to 90 feet; five T-panels beneath each abutment; 36-inch walls around Piers 2–5, up to 60 feet deep; and 120 tieback anchors rated up to 450 kips and 100 feet long.<br /><br />Ground conditions included gravelly layers with sand and silt, with cobbles in the gravel. Excavation used a low-overhead Bauer hydromill, supported by desanding and centrifuge equipment. Quality control included two methods of panel verticality verification, bentonite testing at multiple stages, and crosshole sonic logging (CSL) on every panel.<br /><br />Key challenges included a 30-foot overhead clearance that constrained reinforcing-cage lengths and splicing, and an original T-panel reinforcement design that was not constructible and required redesign. Work in the existing river channel also required extensive dewatering, with more than 40 wells installed and roughly one million gallons of water discharged daily. Flood risk required emergency planning during a major dam release. Obstructions encountered during excavation created additional equipment and cost risks.<br /><br />The project team emphasized three lessons: assess constructability and alternative solutions during bidding; document obstructions and provide timely notice of potential schedule and cost impacts; and establish quality-control and reporting procedures before work begins. Prior communication about the risk of equipment damage from obstructions helped support a successful claim for costly repairs.

Keywords

Santa Ana BNSF Bridge

bridge protection

structural slurry walls

scour protection

Corona California

Bauer hydromill

tieback anchors

dewatering wells

crosshole sonic logging

constructability challenges