Case study: HBR 202 E micropiles, a Hotel in Dubai
Contractor : NSCC International
Locations : Dubai, UAE
Completion time : 2017
Equipment : Drill rig type Hütte HBR 202 E Preventer system with self-drilling micropiles
Production : 300 self-drilling micropiles (total 4,680 m) and 580 tube a manchette steel grouting tubes (total 2,132 m)
A hotel in Dubai, UAE, which was built in 2007 and consists of eight stories and two basements, had undergone some structural movement within the basement, leading to cracked columns, walls and slabs. Since 2017, water has been penetrating through cracks in the basement slab and walls. Moreover, the hotel has been suffering differential settlements.
The issue was that the micropiles and tube a manchette steel grouting tubes needed to be installed in a basement area, subject to a high water table. This could have been achieved with temporary dewatering. However, this was not the preferred option owing to the location of a nearby underground metro station.
The minimum proposed treatment area defined by the consultant represents a total of 2,456.3 m² and 1832.2 m² when excluding the piling caps area.
The scope of works included designing a suitable ground enhancement scheme increasing the density, strength and stiffness on the one hand and reducing permeability of the soils immediately underlying the basement slab on the other hand.