Broadway Bridge replacement, Little Rock, AR

Started by bjrush, February 24, 2014, 04:27:01 PM

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bjrush

Here is AHTD's stockpile of info related to the project.

http://www.arkansashighways.com/broadwaybridge.aspx



As anyone who has been following this project knows, it has basically been a nightmare thus far. Currently AHTD has committed $58M, with another $20M from Pulaski County for aesthetics. I believe that photo is the present design, but I could be wrong. It changes frequently.

Today I heard HNTB was overly conservative on their rebar calcs and they are redesigning with a smaller grade and less steel to save money. Will this have any impact on the project timeline? Is the budget already blown and we are looking for savings already, or is this on the designer?
Woo Pig Sooie


bjrush

Here is a quick primer on the headaches, for those unfamiliar

In 2006, the Arkansas State Highway and Transportation Department (AHTD) began preliminary engineering to replace the Broadway Bridge, connecting Little Rock and North Little Rock over the Arkansas River. The current structure has been deemed structurally deficient and AHTD has scheduled its replacement to be let in 2013. Initially, AHTD budgeted $45 million for the structure's replacement, but this figure rose to $58 million following the Preliminary Engineering Report (PER). AHTD held its first public meeting in July 2011 with local stakeholders. At this meeting, three alternatives were discussed: Conventional Plate Girder, Steel Tied Arch, and Cable Stayed. The public expressed interest in a substantial pedestrian/bicycle facility, the ability to accommodate a future River Rail connection, a pedestrian walkway to Dickey-Stephens Park, and a "statement design" , making the new bridge a landmark for Little Rock and central Arkansas.

Throughout the subsequent year, AHTD continued to meet with officials from Little Rock, North Little Rock, and Pulaski County, as well as Metroplan, the regional Metropolitan Planning Organization (MPO). Individual meetings were also held with major property owners in the impacted area. AHTD held a public meeting in February 2012, offering the following four alternative designs: Plate Girder, Tied Arch, Twin Tied Arch, and Cable Stayed. The standard plate girder design was deemed the most cost effective solution, as well as the fastest to construct. The public approved of the plate girder design, obtaining 40% of attendee's selections. The cable-stayed bridge received such little support it was discarded from future inclusion.

Following the public meeting, Little Rock and North Little Rock proposed a new bridge be built upriver, allowing the current bridge to remain as a pedestrian/bicycle-only "festival bridge" . This idea was largely born over the concerns that a 22-month closure of the Broadway Bridge for construction would have detrimental impacts on both cities' downtown areas. This proposal, called the "Chester Street Bridge"  was not approved by the Little Rock Planning Commission as it would cause economic hardship to businesses already located on Broadway.

AHTD later proposed to build the new facility immediately adjacent to the current structure in an attempt to cut down time to 3 months. Ultimately, this alternative was also rejected. During this time, rehabilitation of the current bridge, partial replacement, and several lane configurations were also debated and rejected.

AHTD completed an Environmental Assessment (EA) and submitted it to the Federal Highway Administration (FHWA) in August 2012. The Department later decided to go forward with the standard plate girder design, stating that if the public wanted additional aesthetics that additional funds needed to be raised. On September 26, Little Rock, North Little Rock, Pulaski County and AHTD agreed to move forward with a double arch bridge, contingent upon the aforementioned municipalities finding funding. Little Rock and North Little Rock had already stated that they would not raise taxes on their constituents, and thus did not offer additional funds for bridge aesthetics. However, Pulaski County Judge Buddy Villines suggested a design and asked the quorum court to approve the additional taxes necessary to fund the additions. With Little Rock and North Little Rock out of the decision-making process, Judge Villines began pushing for a red, white and blue bridge renamed "America's Bridge" , which was approved by a super majority of quorum court members on November 21, 2012. This allowed $20 million of Pulaski County tax funds to be dedicated to paying for the bridge's aesthetics as described by Villines.

Ultimately, a Twin Basket Handle Network Tied Arch alternative was decided upon, with all of the aesthetic changes being paid for by Pulaski County. The Arkansas State Highway Commission (ASHC) approved Villines' request for flags, painted walks, installations honoring veterans and a light display on July 24, 2013, officially titling the bridge "America's Bridge" . After continued discussion, another public meeting was held by AHTD in August 2013 to receive public input with regard to the color scheme of the bridge from four alternatives.
Woo Pig Sooie

AHTD

This is a pretty good summation of it to date.


The anticipated letting in 2013 was to occur because the money for this project had to be obligated by the end of September. That was based on a standard plate-girder bridge. The extras have been a game changer with the schedule. The bulk of the money still had to be obligated by the end of September and it was pretty much down to the wire for Pulaski County to belly up with funding.


Once that occurred, the schedule changed again. Now the consultant team is performing a value-engineering study to refine the design and its costs.


The current plan is to advertise the job in April and allow 90 days for contractors to review and submit a bid for opening in July. This is longer than our standard 30 days because of the confines of this project. About six months of work will have to be performed off-site in a nearby staging area before the bridge is closed to traffic. Current estimates indicate the new bridge will open to traffic 24 months later.





Travel and construction information available at www.idrivearkansas.com

bjrush

Thanks, that was a class assignment  :cheers:

So Broadway will be done before I-30 starts?
Woo Pig Sooie

Alps

Quote from: bjrush on February 24, 2014, 04:27:01 PM
Today I heard HNTB was overly conservative on their rebar calcs and they are redesigning with a smaller grade and less steel to save money. Will this have any impact on the project timeline? Is the budget already blown and we are looking for savings already, or is this on the designer?
Knowing the likely bridge design team working on this, it's not on the designer. We use industry-standard factors of safety for everything. These types of arch being still relatively new, it's quite possible there are "overly conservative" factors of safety built in. We would never decrease a factor of safety beyond industry standard unless the client instructs us, and even then, we would go through rigorous engineering to determine how much it can be reduced and remain safe. Chances are, not a whole lot. I think they're scraping low to try to save money - and keep in mind redesign costs are going to eat some of it up.



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