Along an 8-mi. (12.8 km) stretch of highway on Interstate 89, Kyle Zorawowicz of the New Hampshire Department of Transportation’s construction bureau picks up a number of sheared bolts that popped out of a revolutionary new highway guardrail system after cars struck it.
This laborious work is not beneath a D.O.T. manager, collecting small bolts on a federal road. Zorawowicz is happy to do it. The loose bolts mean that the federal test of the new Nu-Guard rail system, 8 mi. from Bow to Hopkinton, N.H., and its accompanying 5.4 mi. (8.7 km) of concrete medians, save the lives of drivers who crash into them.
The federal government fully funded the $2 million project. The guard rail and median project, a test with national highway safety implications, wrapped up two months early. It was originally set to finish by the end of August. NHDOT finished the work in mid-June.
According to Zorawowicz, the project broke ground on Oct. 23, 2012. It is located on an 8-mi. stretch between Exits 1 and 5 on Interstate 89.
“The final estimate run showed the total cost of the project being $2 million. It was deemed a test project, as we were to install two new types of W-Beam guardrail, along with 1500-feet of pre-cast concrete median barrier, plus pre-cast barrier over the three bridges involved in the project, and pre-cast barrier along the exposed bridge piers on the underpasses within the project limits,” said Zorawowicz.
The two types of guardrail installed on the project were the Nu-Guard post assembly guardrail by the Nucor Corporation, and the GMS Mini-Spacer Guardrail and Thrie-Beam Connection System by the Gregory Corporation. The pre-cast concrete barrier was provided by the Michie Corporation in Henniker, N.H.
“The Federal Highway Administration wanted to see how each of the new types of guardrail systems worked in the state of New Hampshire. In conclusion, both systems are working nicely and how they were designed to work,” said Zorawowicz. The installation process of each was the main difference of the two systems.”
The Nu-Guard system consists of a new type of post. It is a U-channel post that is double the plf of a normal signpost. These posts were easy to drive as they have a small surface area, according to Zorawowicz. The connection hardware used for this system is the same used in a standard run of I-beam posts with W-beam rail
The Gregory system used the normal I-beam posts in a standard run of guardrail, but the connection hardware was different. It consisted of a smaller bolt, 1.5 in. (3.8 cm) length by 5/16-in. (.8 cm) diameter, and “mini-spacer” washers that look like little domes. These connections were harder for the workers to install because the bolt was smaller, according to Zorawowicz.
“Other than that, the actual system itself has worked great and to its design. The reason for the small bolt is to have the bolt shear when a car strikes it, so the rail disconnects from the post easier and is able to guide the car along the rail rather than create a more of a blunt strike against the rail, as older, wooden post rail tends to do,” Zorawowicz said. “We have had several strikes already and I have been able to collect the sheared bolts around the crash site. The installation of guardrail in a median that was in dire need of it makes the Interstate all the more safe for the travelling public.”
Under NHDOT, the companies installed about 28,400 ft. (8,656.3 m) of new guardrail on the project and 2,780 ft. (847.3 m) of standard and modified precast concrete barrier.
General contractor for the work was Weaver Brothers Construction Company Inc., based out of Bow, N.H.
“They have done many projects with the NHDOT and are a fine contractor to work with,” said Zorawowicz.
Weaver Brothers Construction Company has been involved with several projects including:
• Rehab of a bridge covering Route 11 over the Blackwater River,
• Joppa Hill Road reconstruction in Bedford, N.H.,
• Reclamation and paving the roadways and replacing guardrails in Wentworth/Rumney
•Reconstruction of U.S. Route 1 bypass and U.S. Route 1 intersection in Portsmouth
• Reconstruction of the southbound Exit 3 area on Interstate 93 in Salem/Manchester
• Paving 3.85 mi. (6.2 km), with drainage guardrail in Enfield/Lebanon
• The median barrier replacement on Interstate 89 in Bow/Hopkinton
“One of the owners of Weaver Brothers Construction, Jeff Bates, was the superintendent on the project. That helped in communications with exactly what we wanted out of them on the project,” said Zorawowicz. “Adam Bates, Jeff’s nephew and son of owner Peter Bates, was the project manager for the project and he was also great to work with. They do a lot of work with the NHDOT and they know that it really helps make the project run smoothly when everyone is on the same page and working together.
“Collectively, we left no mysteries between each other and that ended up making the project all the more successful,” said Zorawowicz. “We were able to finish the project 2.5 months ahead of schedule because of it. Their web site is http://wbcc.biz/.”
According to NHDOT, a total of 12 sub-contractors worked on the project performing different tasks. The main sub-contractor was CWS Fence & Guardrail out of Andover, N.H.
“CWS Fence & Guardrail installed the entire steel beam guardrail on the project. Beck & Bellucci Inc. out of Franklin, N.H., provided the bridge work on the project,” said Zorawowicz. “For the bridge located on Interstate 89 above South Street in Bow, we were to demolish out the top layer of the bridges, tie in new rebar to the existing rebar, and place concrete over it to create a level surface for the new median barrier.”
A.D. Rossi Corp. out of Danville, Vt., installed a new heat-welded bridge deck barrier membrane to protect the freshly-placed concrete on the bridge over South Street.
“There were also a few minor operation sub-contractors that performed the paving up against the barrier [Black Rock Paving Inc., Salem, N.H.], and the cold-planning and milling of paved surfaces for concrete barrier installation [Continental Paving Inc., Londonderry, N.H.],” said Zorawowicz.
Weaver Brothers’ crew usually consisted of eight people, one superintendent, two foremen, two laborers and three operators, and five tri-axle dump truck drivers. Hours were 6:30 a.m. to 4 p.m., due to traffic control restrictions on Interstate 89.
“Weaver’s work mainly consisted of excavating out existing topsoil in the median, and placing crushed gravel in its place to level up the median from a mainly 4:1 slope to a 10:1 slope, creating a safer area for cars that may travel off the road and into the median,” said Zorawowicz. “They would then top the gravel with 3.5 inches of humus and then have A.J. Cameron’s Sod Farm come on the project to seed the new topsoil.”
Weaver Brothers was required to raise any catch basins in the median to catch any rainfall and/or runoff in the ditch line of the median.
“Some catch basins that we encountered on the project were in less than desirable shape and we asked that they install a brand new catch basin in its place,” said Zorawowicz. “It’s better to fix a problem when you encounter one, rather than let it linger and let the next person that comes along deal with it.”
Weaver Brothers installed the entire pre-cast concrete barrier on the project. One of the major facets of the project was the task of removing a stretch of existing guardrail in the median of Interstate 89 and installing a 1500-ft. (457 m) stretch of modified pre-cast barrier in a semi-super-elevated section of the Interstate.
“We had to create modified barriers in order to accommodate for the super-elevation in that particular section of the interstate,” said Zorawowicz. “Modified barrier is used when one side of the barrier needs to be higher at the base on one side and shorter on the other. The plans did not come with a design for this stretch of barrier and we in the field were shouldered with the task of using the existing roadway to design the sizes of the new barrier.
“Myself, my field help, Weaver’s super and a foreman worked together to take shots using an auto-level to read differing elevations on the northbound and southbound sides of the road in order to calculate how high the barrier needed to be on one side of the road as opposed to the other side of the road,” said Zorawowicz. “I then created an Excel spreadsheet to create my final design of the barrier and submitted it to the Michie Corporation. They reviewed my design and then submitted the barrier heights that they would use in the pre-casting of the barrier.
“After communicating with them and making a few adjustments to the design, we came up with a design that would work in the field. The barrier was then pre-cast and sent to the project a few months later,” Zorawowicz said. “The barrier went in fairly smoothly and looks great today. That was probably the most satisfying part of the project for me. We had to design it with what we had in the field and made it work.”
CWS Fence & Guardrail would normally have a crew of seven people, one foreman, five laborers, and a post-pounder operator. The main focus was to install the two new types of guardrail and/or remove old existing guardrail either in the median or on the shoulder of the interstate.
“Some days they had two crews working, with the same number of workers. One crew would be installing new guardrail while the other crew would be just ahead of them removing old guardrail. It was a very efficient process,” said Zorawowicz.
“I would like to thank the travelling public for bearing with all of the construction delays pertinent to the project. I know it can be a pain to travel through on some days, but it will ultimately benefit everyone in the end,” said Zorawowicz.
For more information on CWS Fence & Guardrail visit http://cwsfence.com/
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