SR 18 Culvert Replacement

Technical Description:

• Span: 12 ft
• Rise: 10 ft
• Length: 120 ft

During heavy storms in late 2004, an existing stone- abutment culvert on State Route 18 washed out. The culvert was blocked with several feet of debris, destroying the adjacent bank and roadway pavement. Because the structure was located on the back side of the Big Bear resort area with minimal access, it was critical to immediately fix the problem and maintain access for emergency vehicles and residents of the area.

Caltrans District 8 quickly reviewed several options to replace the structure, and the CON/SPAN^® precast arch system’s cost estimate proved to be within the budget for this emergency repair. Caltrans set a date to reopen the roadway, hired a contractor and set the design in motion. Considering the slope of the channel in the vicinity of the culvert to be roughly 15 percent, scour was a critical consideration.

The units were shipped to the site for installation within two weeks of project commencement, and the entire structure was installed in one day. The contractor was able to backfill the structure the following day and reopen the roadway that same week.

The hydraulic opening of the culvert was substantially improved over its previous condition. Likewise, the skew angle of the replacement culvert is more efficient than the former structure and follows a more natural alignment.

Technical Description:

• Span: 12 ft
• Rise: 10 ft
• Length: 120 ft