Solving Bridge Problems with Products and Technology
Box Girder Launching System on the I-95 Whittier Bridge
Customer: Walsh Construction
Location: Amesbury, Massachusetts
Challenge: Constructed in 1951, the John Greenleaf Whittier Bridge is currently in the process of being replaced by a new bridge compliant with current safety standards. The high traffic bridge connects Newburyport and Amesbury via I-95 over the Merrimack River. Walsh Construction is employing a rail mounted gantry crane system to simplify the placement of the steel bridge girders and precast deck to create the approach spans. Two 6-foot-tall, 960-foot-long temporary support steel box girders will be launched across temporary piers to create a rail system for the gantry crane to operate on during the approach span construction. The steel box girder arrangement will be moved after the placement of each approach span. It's critical that the two 550-ton temporary steel support box girders move in unison in order to prevent binding or misalignment of the gantry crane operating on top of the rail system.
Solution: Enerpac worked with Walsh to design a box girder launching system that would first clamp, then advance or retract the two separate box girders synchronously. The box girder launching system will be mounted at various temporary pier locations as the gantry crane moves to each stage of approach span construction. The custom launching solution is comprised of four custom long stroke RR-Series hydraulic cylinders for pushing and pulling, eight custom RR-Series cylinders for clamping, and two custom 8000-Series hydraulic power units with networked controls for synchronized movement. Once the new northbound bridge span is complete, the system will then be utilized for the replacement of the southbound span.
Lowering and Leveling a Caisson Pier Box for New Johnson Street Bridge
Customer: PCL Constructors Westcoast Inc.
Location: Victoria, British Columbia, Canada
Challenge: The existing 90-year-old Johnson Street Bridge is located at the heart of Victoria, British Columbia and is in the process of being replaced with a new bridge that will serve the community for the next 100 years. The new bridge is being built adjacent to the existing bridge, allowing the important transportation connection into Victoria's downtown to remain open during construction. The new bridge design includes a 25-meter-long by 20-meter-wide bascule pier box, which will house the mechanical and electrical componentry for opening and closing the bridge span across the marine harbor. The 1,100-ton bascule pier box is comprised of a steel and concrete caisson, which needed to be lowered upon 16 large piers with tight precision.
Solution: PCL utilized a bar lowering method to evenly lower the caisson into its final position on the piers. Enerpac provided 32 CLSG high tonnage hydraulic cylinders and three EVO synchronous lifting systems. All three EVO systems were networked together which enabled a single operator to control all 32 points from a master control user interface. At each pier were two independently controlled hydraulic jacks providing precision lowering of the caisson. Utilizing the Enerpac EVO system in tandem with the bar lowering method, PCL was able to improve accuracy, productivity, and efficiency thus completing the caisson lowering and leveling in three working days.
Jack and Roll System Pulls the Fort Lyon Bridge into Position
Location: Rocky Ford, Colorado
Challenge: Minimizing the amount of time SH 266 was shut off to traffic was a primary objective during the reconstruction of the bridge over Fort Lyon Canal. Utilizing an innovative Accelerated Bridge Construction (ABC) method Kiewit, Jacobs Engineering and the Colorado Department of Transportation developed a plan to build the replacement bridge adjacent to the existing bridge. The new bridge was initially used as a detour while the deficient bridge was demolished. Once demolished, the new bridge was then closed to traffic and needed to be pulled into the position of the original bridge.
Solution: A lateral bridge slide method was utilized to the pull the new bridge into position. Enerpac provided a hydraulic solution capable of lifting the new 85-foot bridge, mechanically supporting the bridge while rollers were installed under it, lowering the bridge onto the rollers, pulling the bridge into placement, lifting the bridge once again to remove the rollers and lowering it into its final position. Enerpac specified eight CLL lock nut cylinders fitted with tilt saddles (four per side) and two ZU-Series hydraulic pumps for the lifting and lowering operations while a RRH hollow cylinder at each abutment pulled a threaded bar to pull the bridge into position.
Lifting the Songdo Cable-Stayed Bridge Pylons
Location: Incheon, South Korea
Challenge: Lifting and positioning two 2,000-ton cable-stayed bridge pylons into place. To prevent counter-balance issues, it was critical to erect both pylon sections simultaneously and within a very tight tolerance. Any counter-balance issues would have created a lopsided load and put undue stress on the center pillar. The lack of a good footprint and the approximately 100-meter lifting height made the lift almost impossible for two cranes or another lifting solution. The need to lift from the central point of the structure required a high capacity lifting solution that could raise both sections simultaneously from a central point.
Solution: Four HSL8500 strand jacks were installed on top of a temporary bent tower and simultaneously lifted both pylons up to their permanent position at 75 degrees. GS monitored and controlled the lift using a computer controlled strand jack system supplied by Enerpac. The whole process was completed in two days.
High Pressure Hydraulics Used in Construction of the New Nijmegen Bridge
Location: Nijmegen, The Netherlands
Nijmegen, oldest city in Netherlands, has been around for a long time, in fact more than 2,000 years. Divided by the Waal River, the city is in the process of receiving a new 1.4 kilometer bridge connecting Nijmegen-West with Nijmegen-East.
The bridge will improve traffic flow in and through the city and reduce center-city traffic. Preparations for the bridge started in May 2011, and completion is scheduled for November 2013.
Contractors Koninklijke BAM Groep NV and Max BÃ¶gl have formed the Bouwcombinatie Stadsbrug Nijmegen (BSN) in order to build and maintain the bridge, which will be known as "De Oversteek" (The Crossing). BAM and Max BÃ¶gl have both worked with Enerpac BV as hydraulic equipment supplier for years and have selected Enerpac to provide most of the high pressure hydraulics used in this project.
The bridge has a main span of 285 meters and a height of 60 meters. Construction requires lifting and precisely setting concrete and steel assemblies. With a wide range of high pressure tools and sophisticated hydraulic equipment, Enerpac is able to provide the needed combination of heft and precision.
Strand Jacks Hoist Main Span
Once the main span is constructed, it is hoisted onto the structure of the bridge with Enerpac Strand Jacks. For each lifting point, a bundle of steel cables called strands, is guided through a hollow hydraulic cylinder; on the top and bottom ends of the cylinder are cable anchor systems utilizing wedges that grip the strand bundle. By stroking the cylinder in and out while the grips are engaged or disengaged, the bridge sections are synchronously lifted into place. "Synchronously" here means that for example in a four-point lift, each of the four lift points is precisely controlled by the digital controller.
The Nijmegen bridge deck is supported by a graceful bow structure. During the concrete casting of elements of the bow structure, a peak load can occur and may cause an interruption in the production process. A series of Enerpac jacks are linked to each other to support and control the pressure during the concrete casting so that the pressure remains constant for best results.
According to Richard Verhoeff, Enerpac Key Account Manager, "The City Bridge is a perfect example of a project in which two of our key accounts work together and both choose the quality, technical knowledge and short communication lines Enerpac offers. We are proud to have the opportunity to offer an overall solution to BSN and to participate in a leading project like this."