Alphathum Tower, NCR

Alphathum is one of the tallest buildings in India which has been designed with the composite construction concept and have been executed at the site. The project consists of three buildings which are connected at the top with the bridge and the swimming pool extending to all the three buildings.

Preliminary Design
Vintech Consultants provided the structural design consultancy for this project which includes to complete project design along with furnishing complete design and fabrication drawings. The project is to be completed in shortest possible time duration with optimized cost. The design team plans to create simple straight-line structure with elegance and should be construction friendly

As the structure is located in highly seismic zone and owing to its sleek geometry and height, the structure is more vulnerable to wind and earthquake forces. Therefore, to cater to the lateral load, an optimum combination of shear walls and bracings were worked out to achieve economy and construction speed. The framing of the building has been designed to provide large office spaces without compromising on the clear floor-to-floor height and foundation is a raft system.

        

“The project is a good experience to be completed in shortest possible time duration with optimized cost. We have to plan simple straight-line structure
with elegance and should be construction friendly”

Manoj Singhal, Managing Director
& Sanjay Vithalkar, CEO Space Combine

Challenges faced
The major challenge was to reduce the structural steel consumption so that the project cost is comparable to the RCC option. At the same time, maintain the constructability for fast execution. After various iterations and discussions, composite structure was chosen. After the choice of material, it is the research on Eurocodes and AISC one has to do as Indian codes do not have composite design provisions. However, the design parameters, load factors, material safety factors had to be modified in order to encompass the Indian construction scenario and honoring the Indian codes of design.

The shear wall construction was a bit slower than the steel frame. However, generally, the shear wall should go above the steel frame with the help of advanced shuttering methods. This problem was rectified by special steel composite connections such that the advancing steel frame does not have to wait for the shear wall construction.

Steel used
The frame is a dual system of Special concentrically braced frame and shear wall systems. The columns are composite column with steel fabricated I sections of 550 grade encased in concrete which eliminates the ‘Achilles heel’ of steel which is buckling and low fire resistance.

The beams are steel beams of 450 grade fabricated and rolled parallel flange I sections designed compositely with the slab. The composite action with the slab facilitates lower depth of the beams, lower material consumption and lower deflections. The shear transfer between beams and slabs is facilitated by channels of 75 mm depth ensuring slab behaves compositely with beams

The slab system is designed by JSPl Speedfloor® system which is as fast and cost effective as the metal deck system and at the same time give higher composite action for the beam design. The bracings are box bracings of high grade steel. Box sections provide great finish and are efficient structurally in providing strength and stiffness in both axes. The connections worked out for the project are bolted connections to expedite construction and get superior quality of construction.

After completing numerous high-rise buildings in RCC, Alphathum project have been a great opportunity for Vintech Consultants to foray in the multi-storey steel buildings. The collaboration with the architects led to efficient design, open spaces and faster construction. Moreover, the association with the Bhutani group, who are the client have been great for Vintech consultants as projected is marketed well and one of the most prestigious ongoing commercial project in NCR

Dr. Vinod Jain
Managing Director, Vintech Consultants

Striking Features
The salient part of the project is the bridge connecting the terrace of the three buildings. It has one of the longest swimming pool in the world spanning more than 200 m in length which will further require expansion joints. It is proposed to have the dampers installed in the bridge to cater to the expected sliding forces and structural integrity.

With respect to the architecture, Alphathum will use solar + wind + fuel cell + geothermal energy systems to reduce dependence on fossil fuels. Double glass glazing, naturally day-lighted interiors and light-colored building rooftops with sky gardens will help reduce heat absorption and ensure energy efficiency. The whole building will be created from an energetic and vibrant pure center.

      

Structural Uniqueness
The structure is unique because of its minimalistic design and a beautiful blend of the structure with architecture. The periphery bracings bring out the structural steel aspect of the building. Due to these factors, the building has been completed in a staggering figure of 4.5 kg/ square feet of structural steel which is an achievement in a 33 storey building in a high seismic zone.

 

Fact File
Client & Developer: Bhutani Infra
Architect: Space Combine
Steel Fabricator: Jindal Steel & Power Limited
Steel Supplier : Jindal Steel & Power Limited
Steel Erection: Waho Infra LLP