Altamount Road is ranked as the 10th most expensive street in the world. Lodha Group acquired the area from the US Consulate for Rs. 375 crore surpassing the bids made by Mahindra Lifespaces and TATA Housing. The previously existing Washington House, home to US Consulate General was a three-storied building, covering an area of 2702 square meters. It falls under the Coastal Regulation Zone 2 and is listed as Grade 3 Property.
Lodha Altamount is a luxury collection that the Lodha group has come up with. It aims to be world’s finest luxurious residential projects at the most coveted location in Mumbai. The project is designed to stand distinctly in the skyline of Mumbai. It has been designed keeping the comfort of the end user in mind with most of the high-end amenities and services.
Lodha Altamount is a residential tower of 40 floors including 8 podium levels. The tower consists of modern architecture conceived by German-Iranian architect Hadi Teherani. The development consists of 52 residences fully serviced by hospitality experts, St. Amand. This half an acre development consists of two floors for recreation. Construction technology using steel frame, this is an all glass façade tower with three sides open for panoramic views of Arabian Sea and the Mumbai city.
The Altamount neighbours Mukesh Ambani’s Antillia and Kumarmangalam Birla’s mansion. Lodha Altamount has created history in November 2015 by selling the most expensive apartment in the country. A 10,000 sq. ft. duplex at this signature development has been sold for over Rs. 160 crore at Rs. 1,60,000 per sq. ft.
The intent of the architect was to create a distinct iconic landmark in the Mumbai skyline. The facade of the building has been envisaged such that residents have privacy as well as a complete view of the sea and the cityscape. It has been designed by keeping the high-end luxury and comfort in mind. The club house, guest rooms, cinema, conference, meeting rooms, pool and other amenities have been designed to create a secluded space within the metropolis.
Client: Lodha Group
Magnusson Klemencic Associates
Sterling Engineering Consultancy
Steel Tonnage: 1643 tonnes
Current Status: Topped-off
All the structural elements are designed to remain essentially elastic during wind and low-level seismic lateral loading, including the core wall coupling beam; the core wall flexure and shear, diaphragms and collectors; basement walls and foundations.
Steel was the best option to overcome the city’s land cost and the time constraints. The floor plans were such that the central core takes the horizontal forces and smaller columns on periphery take the point loads. Flexibility in planning has been achieved by transferring the columns such that they are mostly at the periphery of the building. Steel outriggers have been given at intervals to take the horizontal forces.
Steel helped in optimizing speed of construction, floor area (due to smaller column sizes) and floor height. Steel is also a lightweight construction system which minimizes loads on the foundations, and therefore, saves on sub-structure costs, which can be important for building extensions.
Working alongside the design Architect, the Structural Consultant had the responsibility of executing the project on site with their inputs, without altering the concept. They had to ensure that all the bye-laws have been accounted for during construction. Their role was to co-ordinate with all the consultants and generate construction documents with necessary detailing. To make regular inspections, check on progress and ensure overall smooth execution of the project.
Lodha Altamount will become a distinct landmark which dominates the Mumbai skyline. It has been designed to provide the residents a grand and luxurious lifestyle. Every minute detail has been executed so as to provide maximum user-comfort. Residents would be able to fully customize the space according to their whim. The Building has been designed such that all the residential apartments are elevated above the immediate surrounding structures to achieve a prominent panoramic view of the Arabian Sea and the city without compromising their privacy.
Director, Access Architects
The structure comprises of 3 basement floors + GR + 8 parking levels in which, 4 podiums are for residential parking purpose and rest for GCP parking. The roof of podium level houses a garden, swimming pool & club/fitness centre. There are 32 residential floors above the top podium level with 2 service and 2 fire check levels.
The total height of the structure is approximately 197m, from ground which also includes a 29.7m tall steel crown structure above the roof. The building has an overall ‘T’ shape in plan with projected widths of 31.0m by 24.5m about the main structural axes for the typical levels.
Considering the height of building and its slenderness, the structure is assumed to have a certain amount of sway. To eliminate this, many options were thought of. Tuned mass dampener (TMD) at the top has been considered to negate the effect. Out triggers have been planned to take additional lateral force.
Mat foundation of variable thickness under the entire building footprint.
Floor Framing System
Composite slab and steel beam framing at typical floors.
Steel columns are placed at periphery of the building and in middle of residential units in order to reduce spans allowing reasonable beam depths. The columns in the middle are compromised with the parking layout in lower levels by being transfers at levels above residential car parking floors.
The concrete core walls provide the primary lateral force resisting system. in order to keep on efficient and concentrated lateral system, a closed tube single cell core (large rectangular shape) has been introduced, which is also very efficient for a jump-form climbing form system.
The building structure is built around a RCC core which provides the primary lateral force resisting system. The basement slabs, ground floor and first 5 parking floors are planned as RCC flat slabs with drops supported on RCC columns. The floors above, from 6th to 8th floors (mechanical parking) are structural steel floors with M.S. plate decking. Thereafter, the residential floors are of composite metal deck and structural steel beam framing supported by composite columns of steel and concrete.
As it was unavoidable to extend a few typical floor columns through the parking floors to the raft foundation, steel transfer trusses had introduced to support such columns.
Above 5th floor, the RCC core, in conjunction with two columns interconnected to the core by outriggers is resisting the lateral loads in the Y direction since it is necessary to stiffen the building in that direction to control drift. In the X-direction the RCC core alone resists the lateral loads.
These two columns are composite columns. Below 5th floor the RCC core and RCC columns are acting as a combined unit to resist the lateral loads. The structural composite columns are designed as gravity columns to take up the total gravity load with encasement including the outrigger columns. The column supporting outriggers have designed for axial forces arising due to lateral loads.
Testing of Skills
The significant challenge in this project was designing of embedded connections of the outrigger steel trusses with the RCC core walls. Sequential analysis had used to evaluate the realistic design loads in the members of outrigger trusses and the columns supporting outrigger trusses.
The building is completed in record time, due to advance construction technique of composite structure along with climbing RC core and the construction cycle of 9 levels as follows:
- Concreting for lower 3 level metal deck
- Laying metal deck, laying reinforcement mesh and welding studs at middle 3 levels
- Erection of steel column and beams for upper 3 levels
The RCC slabs and composite metal deck slabs are acting as inplane rigid diaphragms for each of the floors, connecting the columns and the RCC core. The founding strata is hard rock with SBC of 3500kN/m2. The foundation is RCC raft foundation of varying thickness, under the entire building footprint, designed to transfer the loads to the founding strata and resist upward water pressure due to perched water during rainy season. No rock anchors are proposed to stitch the raft to the founding strata.
Grade Fe350 for structural steel
- Universal beams – Ranging from UB254x146x31 to
- Universal columns – Ranging from UC245x254x73 to
- Made-up sections
- Steel girders
- Out triggers