LB 44-510 rotary drilling rig works on particle accelerator
The LB 44-510 rotary drilling rig is being used on its first job site, with two of the massive rigs – first presented at Bauma 2013 earlier this year – working on the construction of a particle accelerator in Darmstadt, Germany.
LB 44-510 is the latest development in Liebherr’s range of deep foundation products and expands the tried and proven LB series of rotary drilling rigs at the upper end of the scale.
With a torque of 510 kNm, it is the largest and most powerful rotary drilling rig currently in operation in Germany. In kelly drilling applications, it is configured for drilling diameters of up to 3 metres and depths of up to 92m. The drilling rig weighs some 170 tonnes and is powered by a V8 diesel engine offering 505 kW (687 hp), compliant with the European emissions standard Tier 4i.
The two rigs are being used on the 200,000 m2 construction site, stabilising the subsurface with cast-in-place drilled piles. In total, some 1,400 foundation piles with a length between 40 and 62 m have been set in the ground.
The site has rigorous demands, as it is located in a drinking water protection zone. All drilled piles are installed down to the final depth completely cased. That means that during the drilling process, the excavated material is removed under the protection of an advancing casing. Because of the high groundwater level and the partially unstable ground, a water load is needed throughout the pile manufacturing process to stabilise the bottom of the boreholes.
A drill bucket is used to loosen and remove the drill cuttings. The efficiency of the rotary drilling rigs working in the rotary drilling method means that the boreholes can be excavated down to the final depth completely cased, without the need for a casing oscillator. This procedure can be realised for the depth needed in Darmstadt with the LB 44-510. Thanks to the high torque and enormous pull force of the LB 44-510, there is no need for the machine units to be changed after the drilling process.
In the past, two duty cycle crawler cranes with casing oscillator were required to reinforce the piles and for concreting, in order to reliably guarantee the necessary torque and pull force when extracting the casing during concreting work. The LB 44-510 provides for substantially greater productivity when installing piles down to great depths, says Liebherr.
The piling operations will form the basis for the construction of the international particle accelerator FAIR (Facility for Antiproton and Ion Research). In total, 35,000 tonnes of steel and 600,000 m³ of concrete are to be used in project, expected to be completed in 2018, when 3,000 researchers from around 50 countries will use FAIR for scientific experiments.