Light House Projects by Skeleton

Project Details
Client:	Ministry of Housing and Urban Affairs & BMTPC
EPC Contractor:	KPR Projecton (LHP Indore) JAM Sustainable Housing LLP (LHP Lucknow) Mitsumi Housing (LHP Agartala)
Architect:	Sthapati Associates
Structural Consultant:	Skeleton Consultants
Steel Fabricator:	Altis Industries Stelloid Infrastructure Struc-Rite Metal Building Systems S. Pushp Steel Structural Trading Co. Infinity Fabtech Arman Steelcon

The increasing demand for residential units in the country with speedier construction, has encouraged use of innovative technologies that are being practiced the world over. Structural steel with its in-built attributes when integrated with these technologies offers added advantages of assured quality, enhanced durability, reliable performance, cost effectiveness, and rapid construction of multi-storey residential projects.

The Ministry of Housing and Urban Affairs had organized a Global Housing Technology Challenge - India (GHTC- India) with the aim to identify and mainstream a basket of innovative technologies from across the globe for the housing construction sector. These should be sustainable, eco-friendly, and disaster resilient. Shortlisted technologies from the challenge are being used to construct Light House Projects (LHP) under Pradhan Mantri Awas Yojana - Urban (PMAY-U) at six locations across India.

The LHPs are being built using cutting-edge technology to demonstrate and deliver ready-to-live houses with speed, economy, and better quality of construction in a sustainable manner, suitable to the geo-climatic and hazard conditions of the region.

Skeleton has been associated from the initial stage on the development of these alternate technologies for use in housing construction. Currently, the company is providing structural engineering consultancy services for three Light House Project (LHP) at Indore, Lucknow and Agartala.

“Skeleton has the expertise and competency in projects using structural steel and alternate technologies. Our learnings from past projects and understanding of innovative technologies has helped us in delivering efficient and optimized structural designs of these projects,” says Nitesh Agrawal, General Manager, Skeleton Consultants.


Structural Aspects of Project
With the aim of using these projects as live demonstration for future projects on different aspects of transfer of these technologies to field application, the structural configuration and construction material was selected based on various parameters, such as functionality, performance, availability, and ease of construction, after brainstorming with each stakeholder.

Skeleton is currently providing structural engineering consultancy to three Light House Projects at Indore, Lucknow, and Agartala. Our learnings from past projects and understanding of innovative technologies has helped us in delivering efficient and optimized structural designs of these projects

Nitesh Agrawal, General Manager, Skeleton Consultants

Project’s structural aspects include the following:

• The residential towers in these projects range from G+6 to G+13.
• Considering the latest developments in the field, demand for cost-effective, rapid and sustainable design, and obtaining desired performance to satisfy various codal provisions, the buildings are envisaged as RC steel hybrid structures.
• The structural system of buildings consists of substructure up to plinth level in RCC and superstructure in ductile RC structural walls with pre-engineered structural steel frames.
• To achieve economy in design, sturdy structural behaviour and to enable faster construction, RC structural walls are proposed only at common areas around Stairs & Lifts with structural steel frames at most of the locations.
• The RC structural walls along with special moment steel frames at selected locations are designed to cater to the lateral load due to wind and earthquake. The other frames are designed as ordinary moment frames to transfer only gravity loads.
• The floor system comprises of steel beams with concrete slab over deep profiled metal deck sheet to avoid intermediate joist to achieve clear height.
• The structural design of buildings is carried out in accordance with the provisions of IS875, IS1893, IS456, IS800 and NBC.
• The structural design of buildings has been peer reviewed and approved by IIT Delhi and committee comprising of experts from IITs, CBRI and BMTPC.

Challenges & Complexities
To make the system future-ready, various challenges and complexities were faced:

• The Lateral load resistant system: Out of the various available alternatives like moment frames, RC Shear walls, braced frames, dampers, base isolation etc, dual system of RC structural walls & steel frames was adopted owing to their aesthetics, functional, structural, cost-effectiveness and constructability. The location of shear walls and special moment frames were carefully chosen to fulfill the behavior in dynamic effects due to wind & earthquake.
• Integration with Shortlisted Technology: The technical details and installation procedure of Shortlisted Technology were understood from the technology provider of each project. The detailing of structural system has been done to accommodate the technology components in design with ease.
• Economic & rapid construction: During the design development, it was stressed to have symmetric configuration and modular design. The structure has been designed & detailed considering high strength factory made pre-engineered steel sections with bolted connection in such a way that it’s easy, repetitive and enhances construction productivity with reliable quality & rapid erection, also reducing wastage and unskilled work.

Building Frames

• The primary frames of the building consist of rigid jointed special moment resisting structural steel frames to cater to lateral loads with RC structural walls.
• Secondary frame comprises of ordinary moment resisting structural steel frames to cater to gravity loads only.
• For floor system, steel beams at frame location were provided without any secondary members such as joists.
• Plate fabricated I section made of high strength steel having yield strength of 345 MPa have been used for framing & flooring members.

Salient Features of Project

• Use of alternate innovative technologies for rapid & sustainable construction.
• In LHP at Indore, Japanese technology of Prefabricated Sandwich Panel system made of cement or calcium silicate boards and cement mortar with EPS granules balls shall be used.
• The light houses in Agartala will be built using Light Gauge Steel Frame (LGSF) System technology innovated in New Zealand. LGSF system is made of galvanized light gauge steel components produced by cold forming method.
• Canada’s technology of Stay in place (SIP) PVC wall will be used in Lucknow. The SIP walls consist of rigid poly-vinyl chloride (PVC) based polymer panels as a permanent stay-in-place finished formwork for concrete.

Advantages of these technologies

• Being factory made, brings speed in construction.
• The panels have lightweight material as core material, which brings resource efficiency, better thermal insulation, acoustics & energy efficiency.
• Being light in weight results in lower dead load of building & foundation size.

Structural Uniqueness of Project

• The superstructure is designed in structural steel which offers flexibility and strength, in addition to being lightweight. Using structural steel, forces in the structure are reduced and its foundations are therefore lighter. This reduction of design forces significantly reduces the cost of both the superstructure and foundations of a building.
• The use of dual system of RC structural walls & high strength pre-engineered steel frames for lateral load resistance offers better and reliable structural behavior and ease of construction where both the activities can be carried out independently.
• The combination of special moment resisting frames & ordinary moment frames helped in optimizing the cost since the lateral loads were transferred at selected locations only and most of the structure needs to withstand gravity loads only.
• High strength plate fabricated I section produced in factories with controlled quality and accuracy have been used to suit the demand of these fasttrack projects.