The construction industry has evolved over the past few years, with the advent of the metro rail. There has been a shift to precast structures and advanced tunnelling techniques. While the Covid-19 pandemic slowed down the pace of work across various metro projects, metro authorities have been swift in adopting digitalisation. At the recent Infrabuild event, the panellists shared their views on new construction methods, the impact of Covid-19, the key challenges being faced and the way forward…
Thiruman Archunan, Director, Projects, Kochi Metro Rail Limited
In the past seven to eight years, there has been an optimisation in station buildings and spaces as well as in the segregation of commercial spaces and property development. Precast structures are being introduced in the Kochi metro. In Chennai, traffic management is a major challenge. In Kochi, the major issues are land acquisition, labour unavailability and poor soil conditions. Kochi Metro Phase I, spanning 26 km, is operational while the 3 km Phase I extension is in progress. Phase II is yet to start.
Contractors need to work at a fast pace right from the beginning of construction work to avoid last-moment hassles which compromiseproject quality. There is a need to improve the strength of skilled labour through proper training to deal with technical labour shortage.
S.K. Gupta, Director (Projects), Mumbai Metro Rail Corporation Limited
In terms of new technology, segmental bridges and launchers for them, as well as shutters for single-span bridges, have become modern. Incremental bridges have also been deployed, which were uncommon in the past. The Delhi Metro Rail Corporation (DMRC) was the first to use extra dosed bridges for a metro rail project. Further, longer cantilever bridges are being constructed. Thus, technology advancement in bridge construction has been huge in India in the past 20 years. With regard to tunnelling, enhancement in tunnel boring machines (TBMs) is being seen and, shuttering system for the New Austrian Tunnelling Method (NATM) has also improved. There is 24×7 online monitoring of underground works. Three types of TBMs are being used in Mumbai Metro Line 3. These have been customised for the local geology. These TBMs are capable of working in closed as well as open mode. They can also work in both weak and hard strata.
Mumbai’s typical topography, scarce land, and high population density are key challenges. Besides, Mumbai faces a lot of activism, hampering metro projects. Government support is crucial for expediting metro works. There has been a delay of six to eight months due to Covid-19-related disruptions. At present, the situation has normalised to 80-90 per cent resumption. Approval procedures have moved to e-platforms. The Mumbai Metro Rail Corporation (MMRC) is currently using 3D building information modelling (BIM) and has planned to switch to 5D BIM soon.
Contractors need to be more professional in terms of contract execution. Greater focus should be placed on quality and safety on the part of contractors. They should respect the contract conditions. They must work on their financial capabilities to overcome liquidity challenges.
Karun Raj Sareen, Director, Major Projects Advisory, KPMG India
The metro rail network has increased at a compound annual growth rate (CAGR) of 20 per cent between 2008 and 2020. Around 87 km of network was added in the past year. Currently, there are 15 operational metro projects, with a total length of 735 km. Around 20 projects are under construction, with a total length of 1060.18 km. Further, 23 newly sanctioned projects will add a network length of around 1,052 km.
The emerging trends in the urban rail sector include new forms of mass transit systems, unbundling of public-private partnerships (PPPs) for metro projects, innovative financing, maximisation of non-fare revenues, and a shift towards integrated mobility. Besides, the latest technologies are being introduced to enhance the efficiency of the urban transport system. Driverless operations, communications-based train control (CBTC) signalling systems, open loop ticketing systems, and increased mechanisation in construction are the key technology initiatives.
There is an increasing focus on solar panels to reduce energy cost. BIM, advanced analytics, drones, and internet of things (IoT)-based digital monitoring systems are being used to manage projects more efficiently and effectively. The focus on indigenisation has increased, with the Make in India and Atmanirbhar Bharat initiatives. The DMRC recently launched i-ATS, an indigenously built CBTC system. Besides, technology is being integrated with physical aspects of the projects in various cities.
Four metro projects have been attempted on PPP mode in India. The demand risk on these projects has been allocated to the developer/concessionaire. This has resulted in financial distress on the projects. Thus, new forms of unbundled PPPs are emerging for fare collection system, operation and maintenance of metro stations and non fare revenue streams in the metro rail. In order to make PPPs a success, risk allocation should be restructured to make it fair and equitable. Meanwhile, metro authorities are looking at innovative funding mechanisms such as land value capture, a transit-oriented development policy, deferred capex and bond issuance for funding projects.
Daljeet Singh, Director, Works, DMRC
In the past 22 years, there has been an evolution in tunnelling from the cut-and-cover method to TBMs and NATM. Further, there has been a shift from cast in-situ to precast structures. Post-1990, safety became an important aspect, with safety audits, trained workers, latest equipment, etc. coming into the picture. With the advent of the metro, environment-conscious construction was given importance. In the past five years, the construction industry has witnessed a shift to digitalisation. The use of BIM is being actively promoted.
Land acquisition was not a challenge in Phase I of the Delhi metro; however, it became an issue during Phases II and III. Then there were issues in getting tree cutting clearance, especially in Phase III, due to increasing awareness and consciousness about the environment. Utility shifting, the lack of a policy for project-affected persons, Archaeological Survey of India clearances, etc. were other impediments. Fund availability from the Japan International Cooperation Agency faced hindrances and delays for Phase IV of the Delhi metro. The recent hike in steel prices is a key concern.
The Covid-19 pandemic has significantly impacted Phase IV works due to labour migration, lower productivity, problems in resource mobilisation, and supply chain disruption. While the situation has normalised to 90 per cent resumption, it is expected to completely normalise in the next six months. A delay of six to seven months is expected in the project timeline. The DMRC has switched to e-office, with 95 per cent paperless operations. BIM was used for designing during the lockdown period.
Aggressive bidding by contractors must be avoided. Further, subcontractors are not paid at competitive rates and payments to them are not made on time. Thorough technical evaluation is needed to select appropriate contractors. There is a need to increase the use of mechanised equipment and focus more on digitalisation.
N.Sridharan Srinivasan, Project Manager, Bangalore Metro RT-03, L&T Construction
The biggest challenge for a metro project is land acquisition. Utility shifting is another key issue, particularly shifting of gas pipelines. With regard to project execution, an additional 6 km stretch of Bengaluru metro elevated extension was inaugurated on January 14, 2021. With this, 48 km of metro network is now operational in Bengaluru. The current underground execution speed is 3.5-4 metres per day. The project is 40 per cent behind timeline due to the Covid-19-induced lockdown. The social distancing protocols to be followed during construction have affected productivity. Thus, there is a delay of around four and a half months.
Slurry-based machines are being used to address geology-related problems to some extent. Advanced technologies and equipment are being used. The majority of the equipment are being fitted with IoT sensors. 4D BIM is being used. The excavation management system and tunnel alignments are completely digitalised. Construction debris is also being recycled.