While the new bridges for the Brazos River crossing on Interstate 35 in Waco, Texas, were opened to traffic last July, work is still proceeding to complete the $43 million project.
While the new bridges for the Brazos River crossing on Interstate 35 in Waco, Texas, were opened to traffic last July, work is still proceeding to complete the $43 million project. The new bridges are part of a major redesign of the crossing which originally had two bridges (one per-side and 625 ft. [190.5 m] in length) with main lanes (three lanes per-bridge).
“We did not have access roads across the Brazos River,” said Jodi Wheatley, Texas Department of Transportation’s I-35 public information officer of the Waco District, “and because it’s a safety concern to not have continuous access roads, we were able to get funding for those bridges ahead of the overall Waco expansion project.”
Motorists and truckers were able to cross the river via the main lanes. Daily traffic on the bridges is nearly 115,000 vehicles.
“In order to get across you had to get up onto the main lanes from the access roads and then get down again. This meant contending with merging traffic and lots of trucks and since it was built 50 to 60 years ago, there were no accommodations for pedestrians, bicyclists and anyone not in a vehicle. It added to the congestion, said Wheatley.
The results of a traffic count, based on findings from last October, will reveal details on the amount and type of traffic using the new spans.
In addition to the bridges, there also was some road work needed to create a connection between the existing access road and the on-ramp, where the traffic would move onto the main lane, and also change the part of the access road that connected to the new bridges.
“We didn’t go as far as changing the first intersection for this project,” said Wheatley, “but we did have to re-arrange on both sides of the river, which led to considerable reconstruction.”
The main lane bridges were built via standard girder construction. With Waco being the largest city in the TxDOT district, having the capacity to handle a large amount of traffic is essential and an additional bridge per side is making a difference. Now motorists can cross the river without having to merge into mainlane traffic.
The new lanes are connected to the existing bridges by ramps.
“Structurally they were not built together but there are ramps where you can get off the main lanes onto the new access bridges and vice-versa. When we get funding for reconstructing the main lanes, we’ll be replacing the main lane bridges as well,” said Wheatley.
The construction plan reversed the standard process of building off-ramps first.
The design of the new bridges is based on an extradosed design, a combination girder and cable-stay bridge. The city of Waco was looking for new bridges for the city to tie it visually to the Historic Waco Suspension bridge, an icon of the downtown area that was built 145 years ago. At the time, it was one of the longest suspension bridges in the world. The same designer prepared the design for San Francisco’s Golden Gate Bridge.
“This bridge is original part of the Chisolm Trail for moving herds of cattle across the river and now it’s a pedestrian bridge,” said Wheatley. “Some of our designers came up with the idea of the extradosed bridge, which has been used quite a bit in Europe and other parts of the world. Until our bridges were completed, there was only one example of a completed bridge in the U.S.
“Cable-stay bridges usually have very tall towers and the design we used allows for much shorter towers,” she adds, “which creates a significant savings in cost, but it has the cable that has some visual elements of a suspension bridge. And this is a short span, so a suspension bridge would have been way out of reason for cost. This was a good combination visually, structurally, and historically.”
TxDOT and other DOTs are considering employing the extradosed design for other bridges. The Minnesota DOT recently contacted Wheatley because they are building a similar bridge and they were seeking information on how TxDOT handled the construction.
The Pearl Harbor Memorial Bridge in New Haven, Conn., has completed an extradosed span on the northbound side. The southbound side is expected to be completed in late 2015, but the design requirements of the Brazos River spans make them “the first in the nation with a completely steel super-structure.”
With proper maintenance, the new bridges should have a lifespan of between 50 to 60 years.
“Usually the superstructure was concrete girders,” said Wheatley, “but in this case, because they have to be specifically designed, they could not use the standard shapes and sizes of concrete. It was actually less expensive to have the girders built from steel. The decks of the bridges are concrete.”
In addition to the long-term planning for this project, TxDOT also faced major challenges in diverting traffic and ensuring that the Lane Construction Company and its subcontractors could bring in their vehicles and equipment and building supplies. This was further complicated by a request from Baylor University, located right on the river, which recently acquired a property on the northeast corner of the bridge to build a new stadium.
“They received a major donation and jump-started their plans to build the new stadium so suddenly all the plans that we had already made for access had to be revamped. They asked us if we could move up the completion date by several months to allow the bridges to be completed before they had their first home game of 2014, which was played last August. We actually had the bridges delivered a little sooner and had a ribbon cutting ceremony in July. Our project managers and contractor got it done and it was impressive,” said Wheatley
Crews are still installing the LED lighting for the bridge — both the safety illumination for travel and special decorative lighting, which was requested by both the city and the university, who are also contributing to the cost of the installation. There also is some landscaping that needs to be completed.
Eric Pruemer, assistant project manager of Lane Construction, said that the lighting will be installed within the next six months.
“We’re just working through some of those issues with the designer to get the lights to work properly — it’s a pretty sophisticated system,” he said. “We have that subcontracted out to Star Operations Inc., but it’s basically taking lights with long lead times.”
Pruemer said that the roadwork covered the approaches from the University Parks Drive intersection on the south side to the Martin Luther King Jr. Blvd. Intersection on the north side. The bridges were the heart of the work, with the extradosed design being a major challenge.
“It gives you an aesthetic look and you don’t have the big cables on top,” said Ernest Trussell, Lane’s project engineer. “It’s a nice looking bridge, and yet for a smaller bridge, it makes sense. The most unique problem was that the engineering for the cable-stay design is in France and we were building all of the steel beams locally, and the engineers that we used were local. Thus there was a lot coordination to make sure that everything was going to fit together.
“The time zones were a great problem, but we got used to it,” he added. “We were sending questions out in the late afternoon and they would reply overnight. First thing in the morning, we would be catching them before their day would end. It brought people together in a hurry because we didn’t have time to waste or we would lose another day.”
The issue with Baylor’s new stadium being constructed simultaneously was another challenge.
“We didn’t realize that it was going to be there when we bid for the job and neither did TxDOT when they put the bridges out for bids,” said Pruemer. “It required a lot of coordination. There were a lot of big structural items coming in for the stadium at the same time we were doing the work and we had to make sure that they had access to get them into the stadium work-site.
“The Texas Ranger Museum is located on one corner, which brings in a lot of tourists and on another corner was Buzzard Billy’s, a popular local restaurant,” he added. “Basically all four corners where we were building the bridge were highly traveled and we could have made a big impact — they all had different hours of business and peak seasons, but the effort paid off.”
Also to be dealt with was a soil stabilization effort, which had Lane bring in DGI-Menard Inc. from Bridgeville, Pa. The firm installed all the controlled modulated columns that had four-foot centers and for which they drilled a 12-in. (30.5 cm) hole placed a grout column all the way down to the bedrock.
“This stabilized everything underneath the roads, retaining walls, and box filters,” said Trussell. “That was quite a feat and to do so many holes in that area, and after that work was done, we had some very significantly deep large box culverts for drainage that were installed and they actually dead-ended it into the river underwater. They were very deep and next to the existing I-35 Mainlane roadway, and at places approximately 10 feet below the water level of the river. Seeing that it is very sandy soil there, you had all that water coming in. Actually, it was more difficult than building the bridge because we’re dealing with the significant amount of groundwater.”
The safety of the construction crews also was paramount, with systems set up to protect them from traffic and to minimize hazards that could arise from the use of cranes and barges.
Lane crews started on the project in September 2012 and delivered the bridges in at the end of June 2014. Pre-planning for the work began around February 2012 and while the bridge was a $43 million project, it was part of a $212 million project that has Lane widening 10 mi. (16 km) of I-35 in Lorena, south of Waco in McLennan County from two to three lanes in each direction. This will be completed in 2016.
“We anticipated most of the problems and came up with solutions,” said Trussell. “We had a contract time where the bridges didn’t have to be installed until about mid-January, but we were able to work with TxDOT to show them how they could be built and cut six months off the construction time.”
Key subcontractors for Lane included: Freyssinet for cable stay design and installation, Hirschfeld Steel for Steel Girder Fabrication, DGI Menard for subsurface improvements, and Star Operations for Signing and Lighting. At peak times, there were about 40 to 50 Lane employees on site and about 10 contractor employees. Lane crews self-performed all of the bridge erection, concrete flooring, and the paving.
There was very little demolition, save for the existing frontage road turn-arounds, which were removed and replaced with the continuous frontage road lanes across the river.
“It not only helps get people across the bridge rapidly,” said Pruemer, “but it is going to help when they do the interstate widening through the center because when they need lane or road closures, they will be able to divert traffic onto those frontage roads; and if there is an accident on the I-35 they have the ability to put traffic on the frontage road and get across the river without a lull or hard-to-follow detour.”
Materials were brought as needed and having access to a nearby municipal parking lot helped, but the work site was tight and the needs of the crews constructing Baylor’s stadium also had an impact.
“In order for them to build the stadium,” said Pruemer, “a lot of the lay down area we would have had went away.”
However, despite all the challenges and issues associated with the project, Pruemer stressed that the experience allowed Lane to hone the skills of their crews and train new construction workers.
“We hired a lot of local people,” he said. “There is a lot of work going on in the area and it’s hard to get skilled people, so we ended up training a lot of operators and carpenters and many will benefit from that.”
The bridge site was 15 mi. (24 km) from the Lorena roadwork site, which allowed Lane to have both projects share equipment, operators, and mechanics.
“We were able to bring in motorgraders, excavators, loaders and other pieces of equipment,” said Pruemer, “and we also have a substantial presence in the Dallas/Fort Worth area and we were able to share a lot of equipment with those locations. We also secured a lot of equipment from rental and lease houses.”
For the two projects, Lane has two mechanical supervisors and nine full-time mechanics.
“We do have three plants on site — an Erie Strayer MG-12CP concrete plant, a Gencor UD400 asphalt plant, and a Pugmill Systems 500B plant,” said Pruemer. “We also have a full eight piece asphalt paving spread and two three-piece concrete paving spreads and these take a lot of mechanics to keep all of that running. Most issues — routine maintenance and immediate repairs we can take care of ourselves. Some of the more complicated that take a lot of time, we prefer to handle at the shop.”
Lane maintains a significant stock of parts and pieces on site and qualified mechanics to effect rapid repairs. At the Lorena site, the company has set up a large tent to serve as a temporary shop, offices for mechanics, fuel and oil storage tanks, and parking areas for the vehicles used by the mechanics.
“Dealing with some of the rock and the weather can take its toll on equipment,” said Pruemer.
Mark Bennis, one the mechanical supervisors, has been with Lane for 15 years.
Lane owns about 50 percent of its vehicles and equipment, with 25 percent leased and 25 percent rented.
“This is a new area that we moved into and we leased a lot of brand new equipment from the area,” said Pruemer. “We have a significant fleet and we work on projects from Maine to Florida and Illinois. We’re all over the East Coast and I’ve had some paving equipment transferred from Maine to here.”