Not just another girder

Kingsford Smith Drive is one of these roads, and Boom Logistics recently completed the erection of two spans of an eight-span bridge extending over the road, the nearby Pinkenba rail line and land between the road and rail line.The two spans were erected over four nights, with 16 SuperTee girders weighing up to 54.8 tonnes on one span (abutment to pier), and 20 beams weighing up to 86.1t over the second span (pier to pier, across the road).Three cranes were used for the project: a 350t Demag AC350, a 220t Grove GMK 5220 and a 160t capacity Demag AC160.Apart from traffic management, other major concerns in planning the lift were the location of underground water mains, Telstra cable, 33-kilovolt power cable and an oil pipeline, which limited the positioning of outrigger pads. It was also vital to avoid eccentric loads on the pier between the abutment and the road, which governed the sequence of lifts so that generally there were two girders placed across the first span, followed by two placed across the second span. In addition, access needed to be maintained to the G James glass factory, which operates around the clock, six days a week.For the first span, the Demag AC160-2 was set up on the abutment and the Grove GMK 5220 was set up on the roadway. Each crane relocated laterally as the work progressed. Beams were delivered to the abutment by a prime mover, dolly and jinker.The Demag AC160-2 was set up with 26.9m of main boom and 39t of counterweight, and worked at a maximum 12m radius, where its lift chart capacity was 36.3t.With rigging taken into account the crane’s share of a dual lift for the beam was 29.05t. This became 34.9t after the de-rating factor for a dual lift was taken into account.The Grove GMK 5220 was set up with a 31.7m main boom length and 77t of counterweight, and worked at a maximum radius of 17m for lifting the shorter beams. Its lift chart capacity at this radius was 36.5t, which comfortably exceeded the actual load, adjusted for dual lift de-rating, of 35t.The AC160-2 picked up one end of the beam using a 50t soft sling from the hook to an 85t capacity triangle with 85t shackles. Forty-tonne soft slings were used between the base of the triangle and the cast-in stressing strand connectors on the beam, with 25t shackles fitted between the connectors and slings.Once the beam was picked up, the Demag AC160-2 slewed to bring the beam within radius of the Grove GMK 5220 while the prime mover and jinker backed towards the abutment with the other end of the beam, keeping the crane rope vertical. The Grove then hooked onto the triangle and winched up as the Demag AC160-2 winched down, until the weight was transferred to the Grove. An elevating platform was used for hooking up the Grove and unhooking the AC160-2.The AC160-2 then picked the other end of the beam from the jinker, and both cranes slewed and luffed until the beam was placed. A similar methodology was used to place all beams for this span, using both lifting positions.The Demag AC350 and Grove were used for dual lifting the longer, heavier beams. The AC350 set up on the road, while the Grove mostly worked from the same position as for the shorter beams.A similar method was used with the AC350 picking up one end of the beam, slewing with it to bring it into radius for the Grove while the transport vehicle moved with the other end of the beam to keep the hook vertical and bring that end within reach of the AC350. The AC350 passed the first end to the Grove, using the triangle rigging, and then picked up the other end of the beam.For this lift it was necessary for the cranes to hoist up, slew and luff to position the beams. The Grove had to slew past its pier and away from the AC350 to allow sufficient space to pass the beam between the cranes for positioning over the piers. At times there was only a little over 1m of clearance between the beam and the boom of the Grove.All work was completed on time and without incident, despite inclement weather for part of the four-day lifting program.A similar method was used for the crossing over the Pinkenba rail line completed earlier in the lift program. Four cranes were involved for the 18m by 38.16m-long beams weighing between 81.90t and 86.17t.The cranes involved were the Demag AC350 with 42.2m of main boom, 142t of counterweight and Sideways Super Lift; a 300t Liebherr LTM 1300-1 cross-hired from Universal Cranes, with 46.1m of main boom, 112.5t of counterweight and a Y-guy system; the Grove GMK 5220 with 27.2m of main boom and 41t of counterweight; and a 170t Liebherr LTM 1170 with 28.9m of main boom and 39t of counterweight.The two Liebherr cranes were set up on the southern side of the rail line, with the Demag and Grove on the northern side. Beams were backed up to the southern side, where the 300t Liebherr picked up one end from the rear jinker and slewed towards the Demag on the opposite side of the rail line. The truck continued to back up with the other end, without intruding onto the rail line. A triangle was used to allow the Liebherr to pass one end to the Demag when it was within radius, and the Liebherr then picked the other end of the beam from the trailer.Neither crane had sufficient radius to place the girders furthest from where they were picked up. As a result triangles were used on both ends of the girder for around half the lifts, so that the Demag could pass to the Grove and the 300t Liebherr could pass to the 170t Liebherr for lifts where the final placement position was out of radius for a four-crane lift, but within radius for a two-crane lift using the Grove and 170t Liebherr.Four-crane lifts were used for the middle beams, while the Demag and 300t Liebherr placed the beams closest to the pick-up point as a two-crane lift. The four-crane lifts were engineered lifts, as Boom Logistics contacted the Demag and Liebherr factories to obtain permission to use lower re-rating factors on these cranes. This was critical to being able to achieve a four-crane lift of the middle beams.Complications for these lifts were water, communication and power services in a corridor between the rail line and northern pier, an open excavation that limited the positioning of the Demag’s outriggers, and a substation and overhead power lines at the northeastern perimeter of the work area.With 29 bridges (other than the main river bridges) forming part of the project, and 17 of these being north of the river, there was a considerable demand for large cranes and heavy haulage transport. The bridge program involves 1000 SuperTee girders (833 for north of the river) of 1500mm and 1800mm depth, as well as 269 deck units of 8-15t, with depths of 450-750mm.The number of other large infrastructure projects in and around Brisbane also meant there were competing demands for cranes and transport. However, work was simplified by the relatively short haul distance between the Leighton Abigroup Joint Venture’s casting yard at Eagle Farm and the bridge erection sites.LAJV North staff work closely with Boom Logistics and the LAJV casting yard to plan the lift and heavy haulage program, working on a four-month rolling projection of transport and craneage requirements that is closely monitored and updated regularly. This helps to ensure permits are in place when required for transporting beams to site from the casting yard. Double handling of the SuperTee girders is minimised by being able to lift the beams straight off transport for erection, rather than stockpiling them.Up to 13 girders have been placed in a night, with the average being around eight. Lifting can take place on more than one site in a night.

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