The Changing Skyline of Dar Es Salaam
The site is opposite the National Museum Village and adjacent to World War II Memorial Graveyard on the north side. Upon completion, the new building is intended to supplement Millennium Towers Phase I which consists of an 8 floor block with offices and a 60 bedroom hotel. To access the new proposed building you will have to turn off new Bagamoyo Road towards National Museum Village just 50m away.
Clients Brief High demand in office accommodation and a new attitude by clientele preferring to be a bit away from the city centre has propelled the financier to develop this iconic structure. Dar es Salaam City is experiencing high traffic jams especially in the city centre.
Facilities
According to Phillip Makota the Managing Director of Undi Consulting Group,Millennium Tower II will change the skyline of Dar es Salaam. It will provide one of the best views for miles around especially within the fast growing Kinondoni District. The building shall have over 19,000m2 of office space and conference facilities as well as 9,000m2 of car park. A 475 seating auditorium will be located at the first floor together with a multi-purpose hall for 500 people at the ground floor.
Millennium Towers Phase II project is expected to offer relief to business people and international organisations that wish to run their business in the outskirts of the hassle and bustle of Dar es Salaam City.
A 150 seat restaurant is provided on the 4th floor. This complements the already operating restaurant at the existing Millennium Tower I. Access to the auditorium has been eased by providing two escalators in addition to six lifts that are located next to the escalators. Vertical movement has been enhanced by providing five lifts with 16 passengers each and a panoramic lift with 18 passenger capacity. A separate service lift to serve the hotel at the 4th floor has been provided.
Air conditioning system for the building has been designed with chilled water system from ground to 4th floor. The tower will have 14 typical floors from 5th to 18th, thereafter it narrows upwards to 27th floor. A VRV air conditioning system has been recommended from 5th to 27th floor. In order to enhance internal services, service ducts have been provided adjacent to the lift shaft running from bottom to top of the building. There is a technical floor on top of 4th floor where services are inter linked . The building services shall include Building Management Systems.
Structural Design
The building structural system comprises of substructure which is made up of 600mm shoring piles as retaining wall to support soil during excavation and double reinforced 300mm thick permanent retaining wall on the inner face. The sub-structure supporting the building is resting on a combination of 800mm, 1000mm diameter piles and raft foundation that supports over 100m tower raising over 27 floors.
Superstructure system comprises of reinforced columns, slabs and beams with lift shaft and two staircases which serve as shear walls to act against horizontal loads. Lifts walls and main staircase have been designed to act as shear walls as well. There are additional columns to support auditorium and multipurpose hall separately. Undi Consulting Group are the lead consultants,project managers and structural/civil engineers to the project.
Materials
Porcelain floor tiles were recommended for public areas whereas ceramic floor tiles will be placed in washrooms and other wet areas. Lift walls are to be covered by polished granite to give the building a rich appearance. External walls shall be covered by plastic alluminum and wall tiles to reduce the need for regular cleaning and painting. Double glazed glass on alluminium structural glazing forms the curtain wall that cover over 60 per cent of the external façade. To reduce heat and make the building partially green, alluminium louvers running horizontally on east and west side of the building have been provided.
Challenges
The structure is being built adjacent to the existing Millennium Towers Phase about 6m meters away on the south side and a few meters from the tomb line of the World War II memorial graves. On the east is the access road which is about 4m away. The challenge was to ensure deep excavation for the two basement floors covering the entire site could be done safely. Shoring piles with a 600mm diameter with ground and intermediate connecting beams were recommended. Construction of the retaining wall is 60 per cent complete and construction of the tower footings is on advance stage.
Project Team
Client: Local Authorities Pensions Fund
Project Managers: UNDI Consulting Group Ltd
Architects (Joint Venture): OGM Consultants & Studio 7 Ltd
Quantity Surveyors: Construction Services Consultants Ltd
Civil/ Structural Engineers: UNDI Consulting Group Ltd
Service Engineers: AGRENEb Consult Ltd
Nominated Contractors
Main Contractor: China Railway Jianchan Engineering (T) LtdElectrical Sub-contractor: DERM Electrics (T) Ltd
Lifts and Escalators Sub-contractor: East Africa Elevators Co. Ltd
ICT and Security Sub-contractor: Techno Image Co. Ltd
Plumbing Sub-contractor China Railway Jianchan Engineering (T) Ltd
