Poplar Point Pumping Station

The Poplar Point Pumping Station rehabilitation project (Division Z) is a component of the D.C. Clean Rivers Project, an ongoing effort to reduce the amount of combined sewer overflow into the District of Columbia’s waterways and improve water quality. Work includes construction of a sewage pumping station (to replace the existing station that was built in the early 1900s), a microtunnel diversion sewer, sewer overflow chamber, main outfall sewer diversion chamber, force main discharge connection chamber and a new microtunnel gravity sewer to serve the adjacent community. In all, 9,500 cubic yards of concrete has been placed. The project is expected to be completed April 2017.

Challenge:

• Large support of excavation (SOE) and multiple pipe penetration interferences created engineering challenges as well as the need for a specialized application: one-sided pours.
• A strict schedule required minimal lifts to speed construction.
• The roof cap slab on the 60 ft. structure is designed to be at least 5 ft. thick in places.
• Multiple design changes by the owner and customer.

Solution:

• Using Framax Xlife wall formwork in combination with construction A-frames and D-22 cantilevered dam brackets enabled true one-sided pours without welded tiebacks—which saved the client time and money.
Framax Xlife and Frami Xlife formwork systems allowed walls to be poured at full lift heights (13.5 ft. with the Doka systems) and at a faster pace. The 60 ft.-tall, 6 ft.-thick walls were built in four lifts.
• The adjustible Staxo 100 shoring tower is ideal for tall heights and high loads, making it the perfect solution for the pumping station‘s roof cap slab.
• The 10k / leg shoring system is also a proven method for shoring slabs at a wide range of heights and is especially effective for heights over 18 ft.
• Proactive, flexible engineering throughout construction solved several challenges and interference issues.