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 that are sustainable, eco-friendly, and disaster-resilient. The 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.
These LHPs are being built using innovative technology to demonstrate & 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 Consultants have been associated from the initial stage on the development of these alternate technologies for use of housing construction. Currently structural engineering consultancy services for three Light House Project (LHP) at Indore, Lucknow & Agartala is being done by them.
With the aim of using these projects as live demonstration for future projects on various 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. The following is brief of various structural aspects of the project:
- The residential towers in these projects are ranging from G+6 to G+13.
- considering the latest developments in field, demand of cost effective, rapid, and sustainable design and obtaining desired performance to satisfy various codal provisions, the buildings are envisaged as RC steel hybrid structure.
- 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 enable faster construction, RC structural walls are proposed only at communal areas around Stairs & Lifts with structural steel frames at majority of locations.
- The RC structural walls along with special moment steel frames at selected locations are designed to cater the lateral load due to Wind & 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 building has been Peer reviewed and approved by IIT Delhi and committee comprising of expert from IITs, CBRI & BMTPC.
In process to make the system future ready, various challenges/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 aesthetics, functional, structural, cost-effective and construct ability. The location of Shear walls and special moment frames were carefully chosen to fulfil the behaviour in dynamic effects due to Wind & Earthquake.
- Integration of Innovative Technology unit with structural frames: The technical details and installation procedure of prefabricated wall units of innovative technology were understood from the technology provider of each project. The detailing of structural steel frames & connections 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 is easy, repetitive and enhances construction productivity with Reliable quality & Rapid erection also reducing wastage & unskilled work.
The Primary frame of the building consists of rigid jointed special moment resisting structural steel frames to cater lateral loads with RC structural walls. Secondary frame comprises of ordinary moment resisting structural steel frames to cater gravity loads only.
For floor system, steel beams at frame location were provided only 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.
The Salient features of these projects are 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. The following are the advantages of these technologies:
- Being factory made, brings speed in construction.
- The panels have light weight 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.
The superstructure is designed in structural steel which offers flexibility and strength, in addition to being light weight material. 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 behaviour 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 fast-track projects.
“With increasing demand of residential dwelling units in country and huge gap created due to speed of conventional construction technique has encouraged usage of innovative technology practiced world over to be used. Structural steel with its in-built attributes when integrated with these technology offers added advantages of assured quality, enhanced durability, reliable performance and cost effective & rapid construction for multi storey residential projects. Over the years, We at Skeleton, have developed expertise and competency in projects involving structural steel and alternate technologies. Our learnings from past projects and understanding of innovative technology has helped us in delivering effective & optimized structural design of these projects.”
Nitesh Agrawal, General Manager-Operation, Skeleton Consultants Pvt Ltd
Client: Ministry of Housing and Urban Affairs & BMTPC
Architect: Sthapati Associates Pvt Ltd
Structural Consultant: Skeleton Consultants Pvt Ltd
KPR Projecton Pvt Ltd LHP Indore)
JAM Sustainable Housing LLP (LHP Lucknow)
Mitsumi Housing Pvt Ltd (LHP Agartala)
Altis Industries Pvt Ltd
Stelloid Infrastructure Pvt Ltd
Struc-Rite Metal Building Systems
S. Pushp Steel Structural Trading Co
Infinity Fabtech Pvt. Ltd
Arman Steelcon Pvt. Ltd