Signature Tower is a proposed skyscraper in Jakarta, Indonesia. The proposed height is It was originally proposed in 2010 and was slated to begin construction in 2015. Planning permission for the tower was granted in late 2015. Construction was scheduled to begin in the third quarter of 2016 assuming a loan of approximately $1.5 billion could be successfully secured. China State Construction Engineering has been appointed to construct the tower. The tower is expected to be completed by 2022. The skyscraper is a part of a 45-hectare redevelopment project SCBD, near the Semanggi Interchange and is just south of the Gelora Bung Karno Stadium. It is within Golden Triangle of Jakarta in Jakarta where the majority of major development areas are located. When completed, the structure will include 6 basement floors used for parking space while the podium will feature retail, convention and entertainment venues with the rest of the skyscraper used as office and residential space.
Engineering and design
Due to the presence of unstable alluvial deposits within the Jakarta Basin and the seismic prone area from where the skyscraper will be built, the design must comply with seismic criteria using a probabilistic seismic hazard analysis defined by the Pacific Earthquake Engineering Research Center, Tall Buildings Provisions and the American Society of Civil Engineers. In addition, wind tunnel tests must be conducted under city regulations due to the height of the building exceeding 50 stories and. Aerodynamic testing was performed by applying a scaled wind velocity on a 1:500 scale model of the skyscraper equivalent to applying an average hourly wind velocity of 40 m/s on the actual design. On 13 July 2017, acting governor of Jakarta Djarot Syaiful Hidayat attended a regional meeting with the developers, discussing about the UDGL and finally reached an agreement to integrate the tower with the ongoing developments of the Jakarta MRT. Djarot later sent a letter to Indonesian PresidentJoko Widodo, requesting him to make the tower to become a national icon.
Foundation
To accommodate the basement floor levels, had to be excavated and dewatered prior to construction. Drilled shaft bore piles measuring in diameter and in length with a spacing of were suspended within a to thick mat foundation system designed to resist wind and seismic loads. This technique also redistributes axial loads on top of the harder and denser sediment underlying the alluvium. Surrounding the basement wall is a thick slurry wall designed to withstand and retain both groundwater and soil pressures.
Structure
To withstand lateral loads, a "core-outrigger-mega-frame" system consisting of two major components will be used. The primary system will feature a composite concrete core connected to 8 surrounding super columns all suspended within a network of steel outrigger trusses that spans 2 stories. A mega frame consisting of a network of 9 belt trusses interlocking the super columns together will make up the secondary system that surrounds the primary structure. The super columns will eventually thin and slope towards the apex to match the profile of the architectural tip. The square concrete core that houses the elevator shafts and stairwells will thin to near the top from a ground thickness of to accommodate additional space. The floors residing between the primary and secondary systems will feature a hybrid design consisting of concrete slabs on top of a metal deck to reduce construction time and reduce additional loads.
