Project Challenge:
Extensive renovation, upgrading and expansion of the Northeast,
Southeast and Southwest Water Pollution Control
Plants began in 1946. Since then, each has grown to become among
the largest facilities of its kind in the country. Klein and
Hoffman (K&H) has been an ongoing participant as structural
Engineer of Record, in these projects that represent a total
construction value of $570 million. The need to design high
quality treatment facilities within a limited space and maintain
existing operations throughout construction were particular
challenges.
Project Solution:
At the Southwest WPCP, rehabilitation of the existing
primary sedimentation tanks required design of various types
and sizes of temporary bulkheads that were necessary to permit
taking various tanks out of service while maintaining sewage
flow through other tanks as required by the construction sequence
procedure.
The sludge digestion tanks were constructed with base slabs
anchored by piles designed to take the uplift load caused by
the groundwater. In the area of the effluent pumping station,
chorine contact tanks, warehouse, and administration building,
the soil was preloaded for a year to consolidate it, while the
soil beneath the aeration and final tanks was replaced with
select fill for several feet depth.
At the Northeast WPCP, construction of the Preliminary
Treatment Building required the use of tie-back anchors on the
excavation sheeting in order to prevent any settlement of the
adjacent existing building. To prevent uplift of the final sedimentation
tanks, tie-down anchors were designed to hold down the base
slab.
OWNER: Philadelphia Water Department
CLIENT: Greeley and Hansen, LLC
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