Dream team on a solid foundation

They lead a hidden existence and yet are beacons of the high art of special civil engineering: the concrete piles that distribute the loads of load-bearing structures in deeper, load-bearing soil layers in deep foundations and thus provide secure support for the foundations of buildings and other facilities. For this purpose, pile drivers and drilling equipment are often used to go many metres deep into the building ground until suitable soil or rock layers are reached and the boreholes are filled with concrete and reinforcement. The dimension of these pile foundations can be guessed at when the huge pile-driving and drilling rigs and the concrete pumps approach on their crawler tracks – visible from afar and so not at all hidden as the result of their collaboration.

Liebherr is the only supplier in the industry that manufactures both machines and digitally networks the duo as a “dream team”. This sets completely new standards for pile foundations in terms of safety, reliability and efficiency of the entire process. Classically, the division of labour for such pile foundations is regulated in this way: A surveyor determines the position of each individual pile on site, the drilling or pile-driving rig moves in, works its way down according to the survey specifications until the concrete pump then gets the signal to fill the borehole with concrete as it is pulled up. This process can take weeks for hundreds of piles, as is the norm for large commercial buildings, for example. When tracked machines, excavators and construction machines have driven over the pile field several times, it is often no longer possible to determine the exact position of the piles.

In order to optimise this literally fundamental process in special civil engineering and to use the equipment and material as efficiently and cost-effectively as possible, Liebherr has networked its machines. For this purpose, the individual work steps of a pile-driving and drilling rig as well as a tracked concrete pump are orchestrated in a unique way via digital control and linked with extensive data analysis. The units also communicate with each other during the recurring processes of drilling, extracting and concrete pumping. The operator of the drilling rig can start and stop the pumping process from his cabin, accurate to the second. The result: significantly simplified work processes, fewer people on the construction site and, in particular, considerable time savings.

PST Spezialtiefbau Süd, for example, recently benefited from this. The company was contracted to anchor 800 piles with diameters of 750 to 880 mm and depths of up to 18 metres in the subsoil at a construction site. The Liebherr LRB 355 pile-driving and drilling rig was deployed for this purpose, using in the double-head drilling method. “The challenge was both the large number of piles that had to be installed in the specified time with only one drilling rig and the exact compliance with the positioning and quality requirements,” reports Philipp Müller, project manager at PST Spezialtiefbau Süd GmbH. “Thanks to the networking of the drilling rig and the tracked concrete pump, it only took 14 minutes to complete a pile, including concreting, under optimal conditions.”

The LIPOS satellite-based positioning system developed by Liebherr plays a key role in this optimised process. It integrates existing machine control systems into the process data acquisition PDE and reporting of Liebherr special civil engineering equipment. The digital drilling plan is transferred to the corresponding drilling and concreting machines for the precise execution of the drilling and piledriving work as well as the concreting. “The construction site personnel thus always have reassurance that there are no gross surveying errors and also have visual control of which piles have already been produced,” says Philipp Müller, summing up the advantages of LIPOS in everyday work. In addition, all the data would be transferred to Liebherr’s MyJobsite application for further visualisation and analysis. This automatically records all relevant process, machine, construction site, weather and position data. In addition, important information can also be added manually by entering construction site events. All this collected data is processed, analysed and stored by the system according to the highest security standards. For Müller, this results in tangible advantages on the construction site: “Personally, I have the expectation that the LIPOS system will relieve the foreman on site, as the system gives the equipment operator more security and clarity about pile numbers and drilling depth.”

Robl Spezialtiefbau GmbH also had a similar experience when it recently had to install over 900 full displacement piles for a new production facility in just three weeks with a diameter of 320 millimetres and a length of between five and eight metres – a job that had to be completed in just three weeks. For this purpose, the company was assisted by two Liebherr LRB 16 and LRB 18 piling and drilling rigs and a Liebherr THS 80 D-K concrete pump.

For Martin Robl, chief executive officer of Robl Spezialtiefbau GmbH, the use of LIPOS and MyJobsite proved its worth in this extremely demanding project: “Because the interaction of the two Liebherr pile-driving and drilling rigs, including accessories, worked perfectly, the planned execution time was undercut by about a week.” The reason: Thanks to the unique networking, the machines would always have worked “hand in hand”, without delay and always exactly according to plan. “Thanks to LIPOS, we didn’t have to make any additional appointments with the surveyor and were able to make full use of every working day,” says Robl. He always had an overview of all the site data via the MyJobsite software solution.

“All the key parameters can be viewed in real time on a laptop, tablet or mobile phone. This way, you always have an overview of which piles have already been completed and which still need to be done,” says the Robl CEO happily. The approach to each individual pile becomes child’s play, without having to pay attention to colour markings or pegs. This boosts the quality of the entire process for all involved. “We are thus experiencing special civil engineering in completely new dimensions right now thanks to digital networking.”