| Application/Advantages of Alternative Project
Delivery Systems |
| Alternate Project Delivery Methods for Brier
Creek Parkway Project |
| By Robby McDonald, Sumter, South Carolina 1-803-938-9530,
mcdonaldr@pbworld.com,
and Jim Ruddell, Herndon, Virginia 1-703-742-5742,
ruddell@pbworld.com |
| The value of construction input for the design,
bid and award processes increases significantly with early involvement
by the construction team. An excellent example of successful collaboration
between our design and construction professionals is the Brier Creek
Parkway project. |
|
Funding and scope are pivotal factors that can alter the construction
start date of a project. When PB’s design and construction professionals
collaborated to provide services for the Brier Creek Parkway Project
in Raleigh, North Carolina, the developer and North Carolina Department
of Transportation (NCDOT) had not yet agreed on either funding or
scope for the construction contract. Extended negotiations delayed
the project by several months, but the developer wanted to retain
the original completion date of December 1998 as long as acceleration
cost proved acceptable. Our goal was to identify a bid approach that
both compressed the original schedule and quantified the cost of acceleration.
Finding the Best Solution
We developed a 2-step solution to meet the owner’s objectives:
- Alter the quadruple 3-m x 2-m x 46-m (9-foot
x 6-foot x 151-foot) box culvert from a cast-in-place structure
to an owner-furnished precast structure
- Insert an alternate bid item for the cost
of an early construction completion date (see Table 1, which summarizes
the construction contract bids for the base bid and for the alternate
bid to complete early).
The cast-in-place concrete box culvert was the major project element
affecting the schedule. The contractor could not optimize mass earthwork
operations until he could haul over the box, and could not complete
water line installation before backfilling the box because the new
water line went into the backfill.
Figure 1: Brier Creek Parkway Fragnet Schedule - Comparison
of Box Culvert Delivery Methods |
After reviewing several options for acceleration, we concluded that
the most cost-effective solution was an owner-furnished precast box
culvert. Our analysis centered on the three fragnet1 construction
schedules that compared the costs of an owner-furnished precast box,
a contractor-furnished precast box and a conventional cast-in-place
box (Figure 1). With the benefit of hindsight, PB’s recommendations
proved quite accurate, as shown in Table 1.
We presented the three schedules and reviewed the cost implications
of each with the developer, who accepted our recommendation to purchase
the pre-cast box and furnish it to the contractor as an “install
only” bid item. At the developer’s request, we then solicited
bids from potential suppliers. We narrowed the field to two suppliers
based on the following criteria:
- Ability of the precaster to prepare shop
drawings for NCDOT review
- Product quality
- Product cost
- Ability to meet schedule
Table 1: Brier Creek Parkway Schedule- Actual vs. Planned
Completion Dates
 |
Table 2: Comparison of Bids
 |
We discussed project requirements in detail and solicited a written
schedule and cost proposal from both suppliers. After reviewing the
two proposals, we recommended Gifford-Hill Concrete Products of Chesapeake,
Virginia. On March 13, 1998, the owner issued notice-to-proceed to
Gifford-Hill for shop drawings, precast concrete elements and delivery
to the project site.
The Cost of
Acceleration
Although our recommendation for an owner-furnished, pre-cast box culvert
cut nearly three months off the construction schedule, we still considered
the schedule ambitious. We worked with the owner to provide an alternate
bid item in the contract for completion by December 15, 1998, which
enabled us to quantify the cost of acceleration. A comparison of the
four lowest bids is shown in Table 2.
The developer awarded the construction contract to Rifenburg Construction
Inc. Construction was proceeding on schedule when the owner added
surface asphalt to the contract scope in November 1998. Owing to inclement
weather, the owner granted the contractor an extension. As of March
1999, the project is complete, pending final acceptance into the NCDOT
roadway system.
By tailoring two contractual elements to meet the owner’s needs,
PB delivered bid documents that compressed the original construction
schedule by five months and quantified the cost of acceleration as
a bid alternate. |
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Robby McDonald is the construction engineer
for the Brier Creek Parkway project. His experience includes wastewater
treatment plants, water distribution systems and highway construction.
In 1998, Robby was named a finalist for Construction Services company’s
Inspector of the Year.
Jim Ruddell is operations manager for the Construction Services
company’s Mid-Atlantic region, a senior project manager and
professional associate in construction management.
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