Three duty-cycle crawler cranes from Liebherr recently carried out foundation work on a residential development in Kowloon, Hong Kong. This involved the installation of 14 piles, which serve as the foundation of the building.
The cranes included two units of HS 885 HD and one of HS 8130 HD, each fitted with a mechanical grab and an oscillator. In order to achieve the necessary depth of 50 m, the contractor required 10 working days per pile.
According to Liebherr, the long production time was due to the difficult ground conditions, including groundwater followed by rock with a high strength of 150 MPa. To penetrate this hard layer, the RCD method was used. With a diameter of 3 m, up to 300 cu m of concrete was required for the completion of each pile.
Another challenge on the project was the restricted space. The jobsite is located in the middle of a residential area and borders directly on existing buildings. Kowloon, together with Hong Kong Island and New Territories, is one of the urban areas of Hong Kong, which has a total population of seven million. In order to keep the noise level for the residents as low as possible, work may only be carried out between 07.00 and 19.00 hours, six days a week.
For such applications, Liebherr provides optional assistance systems. Using the eco-silent mode, the engine speed can be reduced to a predefined level. Therefore, both a significant reduction in diesel consumption and lower noise emission can be achieved.
In addition, the automatic engine stop control system from Liebherr offers an efficient and environment-friendly solution. After checking certain system functions, the engine is switched off during longer work interruptions.
The deep foundation work lasted for six months and was recently completed. The contractor on the project was Vibro (HK) Ltd, which specialises in foundation work in difficult ground conditions.