- First Liebherr drilling rig for Delta Foundations
- LB 20 in Kelly drilling operation
- Efficiency despite varying soil conditions
Nenzing (Austria) Jänner 2017 – Liebherr LB 20 rig is used by UAE-based Delta Foundations Co to drill 200 piles in four months. The task of the company’s first Liebherr rotary drilling rig is to install the piling for a four-star hotel at Dubai’s Culture Village development.
Culture Village is a mixed development that is being built alongside Dubai Creek, where a 6 km boardwalk and a marina have been constructed. Plots of land have been allocated to a number of developers for the construction of apartment buildings, hotels, retail space, offices, a mosque, and a museum.
The basement excavation for the four-star hotel has already been completed, and a diaphragm wall constructed around the perimeter. Delta Foundations was awarded a contract for the driving of 200 bored piles underneath the basement level. Delta’s project engineer Mohamed Osama said this is the first project on which the highly mobile and compact Liebherr LB 20 has been used. The rig was supplied to Delta by Liebherr Middle East FZE, which is based at Jebel Ali Free Zone in Dubai.
“We have been using other brands of rotary drilling rigs, but we needed to invest in a new machine and were impressed by the specifications of the LB 20,” he said. “This contract is therefore very much a learning process for us.”
The machine is being used in a rotary Kelly configuration, with a casing oscillator. Delta is driving two depths of pile, one to 24 m and the other to 29 m, depending on the needs of the structure. There are two diameters of pile, one at 70 cm and the other at 100 cm.
“Even within this small area the soil conditions vary,” says Mr Osama. “On average, the first 10 m is sand. After that we begin to find about 4 or 5 m of soft rock. Beneath that the rock becomes harder. What we do have to contend with is the water table, which is at 4.5 m below our drilling surface. Even so, we are completing the drilling at the rate of about one hour for a 24 m deep, 70 cm diameter pile. So we shall finish our contract in a comfortable timescale.”
The LB 20 works at a maximum torque of 230 kNm, which allows for a fast drilling cycle, and with a Kelly drilling configuration it can reach a depth of 52 m.
Mohamed Al Amin was the first of Delta’s operators to be trained to use the LB 20. “The LB 20 is an easy machine to operate, and once you have worked with it, then you do not really want to work with any other kind of rig”, he says.