The main contractors of the 226m Jakarta office tower project are Shimizu Corporation from Japan and Bangun Cipta Kontraktor from Indonesia. Completion of the high-rise is scheduled for 2021, while the foundation work has been underway since May 2017, with which the local subsidiary of Bauer Spezialtiefbau, PT Bauer Pratama Indonesia, has been contracted.
In addition to the production of several test piles, Bauer's scope of works also includes drilling 462 foundation piles, each of them 69m deep and with a diameter of 1.2m. Two Bauer rotary drilling rigs, a BG 28 and a BG 30, are used for this. Bauer Indonesia is also producing a 44m-deep diaphragm wall with a GB 34 grab, which will serve as a retaining wall. The four basement floors of the future high-rise will be built using the top-down construction method.
One of the challenges, said project manager Anang Hidayat, is the relatively small area on which the foundation works are taking place. Aside from that, the construction site is located in the centre of the megacity, creating specific requirements for logistics as the timeframes for the delivery of concrete or removal of the excavated soil are severely limited.
Despite this, the foundation work, which is being carried out in double shifts, is coming along well, meaning that the drilling and diaphragm wall work will likely be completed by January 2018, as per the contract schedule.