WEDNESDAY, OCTOBER 20, 2021
Dutch-based heavy lifting and transportation contractor Mammoet has developed a unique cantilever setup on self-propelled modular transporters (SPMTs) to set bridge girders quickly and safely. Mammoet reports that the approach reduces installation time from one day to one hour.
The idea was employed for Mammoet’s contract to complete two phases of work to set 12 steel rail bridge girders in Colorado. The location of the girders directly under Interstate 70 prevented the company from using cranes to place them.
Each girder measured approximately 21 meters (roughly 70 feet) long and would be set on bearing pads over an existing dirt pit.
Initially, Mammoet planned to use a skid system to launch each girder over the pit and transfer them to another skid system. This system would shift the girders sideways above the bearing pads. Each girder would then be lowered by climbing jacks into their final position. This method would reportedly set up to four girders in three days.
According to the press release, the site’s field supervisor and team came up with a process to utilize two 30-meter (98-foot) spans of transport frame beams lashed to the back of an SPMT trailer, along with 27 tons (60,000 pounds) of counterweight stacked over the lashing arrangement against the girders’ 18-ton (40,000 pounds) weight.
#Mammoet was contracted to assist in two phases of work to set twelve steel rail bridge girders in #Colorado. Mammoet's innovative method ultimately reduced the install time from one day to just one hour!
— Mammoet (@mammoetglobal) October 1, 2021
Click to read more: https://t.co/2FIKT0Ne6L pic.twitter.com/pvwp9qpzra
The idea was confirmed and approved by Mammoet engineers, as well as the client. Prior to execution, the configuration was assembled and tested at Mammoet’s yard to ensure effective performance before moving to the site location.
A crane was used to set each girder from the roadway onto the SPMT trailer configuration. The cantilever trailer then drove into position so that the girder’s center of gravity was underneath the air hoist.
Another 3-ton chain hoist was used to secure a small fraction of the girder weight near the front end of the trailer to prevent unwanted movement during driving and lowering. The girder was then lifted and driven further forward about 37 meters (121 feet) until it was over its set position, then lowered down approximately 2 meters (6.5 feet). It was then secured and unhooked from the cantilever.
According to Mammoet, the decreased handling time made this method of operation safer and allowed the site to be released ahead of schedule, reducing disruption and total time onsite for its scope and keeping the customer’s budget and schedule in order.
Recent Mammoet Bridge Projects
Mammoet provided a self-propelled modular transport for the 2019 replacement of Pittsburgh’s Shaler Street Bridge, which was replaced with 70-foot-long, 270-ton bridge spans totaling more than 600 feet long.
The equipment provided by Mammoet implemented a series of small hydraulic trailers, which can each hold 30 metric tons. The trailers were then used to move the bridge to where it needed to be. The project is an example of accelerated bridge replacement, a choice that can reportedly cut down on the time traffic will be negatively impacted. (Traditional construction would have warranted a six- to eight-month closure.)
In September, Mammoet assisted Archer Western and De Moya Group with the removal of the westbound State Road 84 bridge over I-95 in Fort Lauderdale, Florida.
According to reports, the bridge was originally slated for demolition following a two-stage, months-long plan. The first stage, which was slated to take 15 days, would have involved the demolition of the south side of the bridge in place. Then, some months later, stage two planned to involve the demolition of the north side of the bridge, also in place, over a 15-day period.
To reduce the disruption of traffic by some several weeks' time, Mammoet suggested a faster alternative, involving the removal of the bridge in just one night by utilizing the ABC method. According to the Federal Highway Administration, ABC technologies are changing the way many state DOTs operate by replacing bridges within 48 to 72 hours, thus reducing planning and bridge construction efforts by years.
The FHWA adds that ABC planning and construction methods, designs and materials produce safer, more durable bridges with longer service lives than conventional bridges.
The entire operation was reported to have reached completion within eight hours overnight, successfully keeping lane closures to a minimum and causing normal traffic patterns to resume ahead of schedule.
Tagged categories: Bridges; Bridges; Girder; Infrastructure; Program/Project Management; Project Management; Transportation
