Owner: City and County of San Francisco
Contract value: $4,140,500
This design-build project will rehabilitate 2,600 ft of an existing 36-in steel sewer force main. The project is located on The Embarcadero, a major thoroughfare in the heart of San Francisco. The rehabilitation of the pressurized sewer line will be performed by slip lining a new 28-in HDPE pipe inside an existing 36-in line.
The major challenges of this project include the following:
- Work is carried out in the middle of the road on one of the busiest streets in San Francisco. Extensive traffic and pedestrian control is required.
- Slip lining 28-in HDPE pipe for 2,600 ft length with internal existing pipe obstruction such as Weko seal, double vertical and horizontal offsets within the existing pipe.
- In order to slip line watertight excavation "pits" need to be constructed. All the pit locations are in within very close proximity to the Bay. The groundwater table is extremely high and greatly affected by tide.
- The shutdown window to work within the operating pipeline is extremely short.
- The existing pipe is between 5 ft to 15 ft in depth in an area built up with fill since the 1800’s.
- Emergency contract, which means the project needs to be designed and constructed in 120 calendar days. The 120 calendar days include material procurement.