Since last November two Liebherr rotary drilling rigs have been operating at Tervita Drilling, and Coring Services’s project in Alberta. The LB 24 machines have been involved in the construction of a new office building in the city of Calgary. The two LB 24 had to do various deep foundation work to install the shoring, as well as the building’s foundation.
Secant Pile Wall and Cast-In-Place Piles
On the jobsite the Liebherr rotary drilling rigs were used for two major tasks. On the one hand, the machines had to install the shoring by constructing a secant pile wall. Piles with a diameter of 880 millimetres were drilled approximately 15 metres into the ground. The jobsite’s adjacence to the Bow river was one of the key challenges in the secant pile wall construction since the wall has to withstand a constant hydrostatic pressure.
For the foundation of the building, the rotary drilling rigs had to drill cast-in-place piles with diameters of 1,300 millimetres about eight to 10 metres into the ground, which consists of sand and gravel followed by cobbles and finally bedrock. The job was carried out using the Kelly drilling method with sectional casing.
Thanks to the powerful engine of the LB 24 one pile was completed within two hours. Each of the machines was thus able to finish ten piles every day. The Liebherr rotary drilling rigs thus helped to keep deep foundation work within the scheduled period of time.
Main advantages of the LB 24
According to the customer the LB 24 once more proved to be a very strong and reliable machine. Another distinguishing advantage is its efficiency as the LB 24 provides high output while the fuel consumption is kept considerably low. Furthermore, the rotary drilling rig can easily be transported at and between jobsites and thus facilitates the planning work of construction companies.
The comfortable cabin, the clear touch screen display illustrating relevant information, a great number of pre-programmed functions or the memory function on joysticks are just a few features of the LB 24 that contribute to its ease of operation.
By Tobias Fröhlich