Delta Foundations uses Liebherr LB 20 rig to drill 200 piles in four months.
The UAE-based piling contractor Delta Foundations Co is using its first Liebherr rotary drilling rig on a four-month contract to install the piling for a four-star hotel at Dubai´s Culture Village development.
The rig was supplied to Delta by Liebherr Middle East FZE, which is based at Jebel Ali Free Zone in Dubai.
The LB 20 is a compact rig that is highly mobile, an advantage on this application as the site footprint measures only 60 m by 40 m and the site is consequently congested. Culture Village is a mixed development that is being built alongside Dubai Creek, where a 6 km board-walk 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 says ´This is the first project on which the Liebherr LB 20 has been used.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 adds. ´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 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,´ says Osama.
He adds, ´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 time-scale.´
The LB 20 works at a maximum torque of 230 kNm, which allows for a fast drilling cycle, and with a Kelly drilling configuration 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 don´t really want to work with any other kind of rig,´ he says.