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January 2007 Accelerated Construction Technology Transfer Building on Success
"The workshop incorporated people familiar with similar construction projects but without the predetermined limitations set by local communities and departments."
District Construction Engineer
As of the fall of 2006, six ACTT projects had reached or were approaching the letting/construction stage, with one job complete. Even though the scope of the projects varies greatly, all six States report either significant savings or vital lessons learned as a result of the ACTT process.
The Oklahoma Department of Transportation, for example, has realized an estimated $15.8 million in savings as a result of its ACTT workshop for the $360 million I-40 Crosstown project in Oklahoma City - and the project is still in the design phase! A breakdown of recommendations and the resulting savings is provided below:
- Complete early geotech investigations. Early geotechnical investigations exposed a layer of questionable material in the vicinity of the depressed section of the Interstate. Adjustment of the proposed grade has produced approximately $10 million in savings due to reduced excavation costs, retaining wall changes and drainage system modifications.
- Eliminate cast-in-place wall design. This has been incorporated in all possible areas. The change to mechanically stabilized earth (MSE) walls should produce a savings of approximately $1.5 million.
- Use full closures and combine closures. Elimination of the Western Avenue detour will save approximately $1 million due to the length of the detour and the two at-grade railroad crossings that can be eliminated.
- Have pre-established borrow sites. The department has been securing and stockpiling fill material as local conditions allowed. Additionally, cooperative efforts with the City of Oklahoma City have enabled the department to secure approximately 600,000 cubic yards of material from a city construction site. Cost savings should be in the range of $1.8 million.
- Remove eastbound frontage road between Pennsylvania and Western. Removing this element should result in a savings of $1.5 to $2 million.
"This was a worthwhile and beneficial effort," says ODOT Project Development Engineer John Bowman. "The process was a well defined and structured process that does not need changing."
The Louisiana Department of Transportation and Development (DOTD) reports similar results. The DOTD awarded the contract for its I-20 Rehabilitation project in West Monroe in August 2005, and construction was completed in March 2006. According to District Construction Engineer Marshall Hill, the ACTT process offered a number of benefits to the DOTD, with the agency adopting several recommendations from the workshop:
- Use very early strength latex modified concrete.
- Use precast F-shaped fascia for barrier rail upgrades.
- Hydroblast and overlay one and a half inches without raising the road irons.
- Temporarily modify the geometrics on local adjacent roadways (Layton and Calypso) in order to detour two lanes of I-20 traffic for weekend and night closures.
- Develop a comprehensive public relations campaign.
- Incorporate innovative contract methods.
- Optimize the letting date.
- Utilize full bridge closures as much as possible.
"It was always our understanding that we had to add depth to the concrete," Hill says. The department hadn't utilized very early strength latex modified concrete in a number of years, so DOTD staff didn't realize it could be utilized in such an application. Those changes, along with an incentive to construct expeditiously, reduced the construction timeframe from 225 proposed to 125 actual days. The DOT was so pleased with the results that it recently held a mini-workshop for the upcoming extension of the West Monroe project.
According to their survey responses, both the Wyoming Department of Transportation (WYDOT) and the Tennessee Department of Transportation (TDOT) garnered comparable results from their ACTT workshops.
Since WYDOT held a workshop for its US 287/26 Moran Jct.-DuBois project in September 2004, the agency has implemented recommendations from the construction, geotech, environment, and marketing/public relations groups on the two segments let to contract, and a number of recommendations are being explored for the segments still in the design phase. The only change Chief Engineer Keith Compton would suggest is a more focused approach so that WYDOT could receive even more detailed recommendations.
The major innovation adopted from TDOT's I-40 from I-275 to Cherry Street, Knoxville workshop pertains to the design of the signature bridge for the project, says TDOT Engineer Duane Manning. "The original design had intermediate bents or columns on either side of the roadway, and the final decision was to lengthen the spans, use caisson footings and limit the amount of work directly adjacent to the Interstate." This, in turn, shortened the construction timeframe and lessened the impacts on the traveling public.
The Montana Department of Transportation (MDT) reports similar benefits for its US 93 from Evaro to Polson project on the Flathead Indian Reservation. The department conducted the US 93 ACTT Workshop in January 2004 and awarded the first of 10 construction contracts in April 2005. According to Chief Engineer Loran Frazier, MDT incorporated a host of ACTT recommendations, including the following:
- Brand the project.
- Hire a public relations firm to document the process and the project.
- Prioritize parcels for acquisition.
- Allow concurrent appraisal review by MDT and the Tribes.
- Consider advanced funding of utilities.
- Utilize A-plus-B bidding and contractor incentives.
- Institute penalties for impacts to "do not disturb" areas.
- Limit the use of pre-approved and mandatory borrow sources.
- Allow one-lane nighttime operation.
"The workshop was very successful in opening up the minds of the people who are very familiar with the various disciplines necessary to build a project. This open atmosphere...allowed for creativity in a realm where most rarely deviate from the standard guidelines or processes."
The results have been significant, Frazier says, but could have been even more so had the workshop been held earlier in the project development process, where geotechnical and structures recommendations could have been incorporated.
"It was a very useful workshop," he says. "The results benefited the project as well as practices across the State. However, the workshop was late in the design process so wasn't as effective as it had the potential to be."
The Minnesota Department of Transportation's (MnDOT's) experience with the ACTT process parallels Montana's in many ways, especially in terms of timing.
MnDOT incorporated a number of ACTT recommendations in preparing for the estimated $245 million I-35 W/TH-62 Crosstown project, including the development of innovative financing methods, the establishment of a pre-construction critical path method (CPM) and the securing of all necessary right-of-way (ROW) prior to the anticipated letting. The timing of the workshop proved detrimental, however, as MnDOT had just completed the geometric layout and was in the process of obtaining municipal consent. The next time, MnDOT says, it would host the ACTT workshop one year in advance of municipal consent so that major design changes could be considered.
Surprisingly, says Area Engineer John Griffith, MnDOT's use of innovative financing methods also caused some concern for the DOT, with the agency receiving no bids when it advertised the project for letting in March 2006.
After its ACTT workshop, the DOT developed a payout curve and time of completion that would force the contractor to work in advance of payment at various points during the four-year construction process. MnDOT extended the advertising period from 12 to 16 weeks to provide the contractors time to prepare for the letting - but to no avail. "The contractors felt that they were somewhat blindsided by that," says Griffith. "When it was all said and done, they felt our estimate of $245 million wasn't even close."
As a result, MnDOT has repackaged the project so that the payout schedule matches the CPM schedule, and it plans to re-advertise the project in March 2007.
Even though the project was not awarded as planned, Griffith believes that the work will be accomplished more quickly and with fewer impacts because of the ACTT process - a dividend realized by all of the DOTs surveyed.
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