L&T GEOSTRUCTURE IS DRILLING DEEP FOUNDATIONS FOR THE BULLET TRAIN

Another challenge is to test the soil and rock samples collected from the 2,450 boreholes. Engineering property testing procedures are complex, time consuming, requiring highly skilled trained technicians to conduct the tests, and qualified geotechnical engineers to interpret the test results. Secondly, the client, NHSRCL (National HighSpeed Rail Corporation Limited) has mandated that all samples be tested in laboratories accredited by the National Accreditation Board for Calibration and Testing of Laboratories (NABL) to ensure accuracy and reliability of the test results. All the 20+ NABL accredited laboratories in and around the project stretch were identified, scrutinized, and inspected by both the client and L&T and only a handful were found to possess even the right equipment and resource to cater to the testing demand of the project. “While we were required to test about 400 samples a day, these local labs, at best, were only capable to test some 20 samples a day,” points out Tsn, “and therefore considering the quantum of testing and our stringent deadlines the only alternative was to set up our own facilities.”

The world’s largest onsite testing facility: The L&T GeoStructure team has thus successfully established a modern, state-of-the-art Geo Technical Testing Laboratory that is the world’s largest such onsite testing facility. Set up over an area of 5,000 sqm at Anthroli in the outskirts of Surat, it is equipped with state-of-the-art automatic and digital testing equipment with accuracies meeting all the codal provisions. Housing 140 automatic triaxial and 350 automatic consolidation equipment, this lab is by far the highest installed capacity of engineering property test equipment in India and about 100 times the capacity of an existing typical geotechnical laboratory. “The lab has been designed and equipped to conduct 3,500 tests a day,” shares a proud Nakkiran, Head – Special Projects, L&T GeoStructure. “It is manned by 180 specially trained technicians to conduct and record test data that is evaluated, interpreted, and reported by 20 qualified and experienced geotechnical engineers to ensure correctness, accuracy and reliability of test results.”

Digging deeper to progress

It is natural for a project of such scale and complexity to throw up challenges. For Project Director, Sanjeevi Perumal, a couple of challenges that are keeping him awake at nights is the inaccessible, marshy areas they must contend with that the 236 km stretch runs through, the difficulty of mobilizing GTI & hydraulic piling rigs and associated equipment and clearing work fronts for both GTI and piling works.

A particularly severe monsoon threatens to wash away three months of their effort, but the team is pushing forward despite many challenges. Allocation, sharing and monitoring resources by ensuring parallel working at all the 5 sections is critical in addition to workmen mobilization and availability, to overcome COVID disruptions.

The GTI works kicked off in January 2021 and till date, about 60% of the scope has been covered; the field investigation works are expected to be completed by December 2021 and the laboratory testing works by March 2022. “By parallelly installing the working piles, we have completed 700 piles till date despite the various challenges,” points out Sanjeev, putting up a brave front. “We have already mobilized 35 hydraulic rigs and plan to increase our speed and scale in the coming months post the monsoon to complete the total piling scope of works by August 2022.”

Driving progress

“Both packages are two significant projects within a project to be completed in 36 months from pile to rail,” remarks Project Director, T Harmis Jose, who must deliver both the UP and the DOWN Line railway grade separators running over New Katni Junction & Katni Murwara yards, that involve the construction of rail viaducts on pile foundations, composite steel girders & deck slabs, open web girders, retaining walls, minor bridges, earthwork & allied other civil engineering works.

Harmis and team have already completed 50% of the pile foundation works in Package 1 that is scheduled to be completed by end 2021 while in Package 2, the team has completed 60% of the pile foundations and aim to complete the task by October 2021. While work on the substructure is in progress at both packages, Harmis’s target is to complete the total civil works, excluding the deck slabs, for Package 1 by October 2022. “Half the value of the contract is structural steel works,” he mentions.

The fabrication of the workshop is in progress and the fabrication work will commence once the team receives the RDSO approval. “With our capacity of 2500T per month and starting from October 2021, we should complete the fabrication work by March 2023 and simultaneously, the erection by April 2023,” informs Soumendra Kishore Roy Choudhury, Lead Fabrication & Erection (for both packages).

“What are construction projects without challenges?” laughs Head Project Planning (for both packages) – Shekhar Keskar. “We have our fair share in the form of existing & unknown and unidentified underground utilities, Signalling & Telecommunication cables, OFC cables, electrical cables and the like, insufficient supply of OPC 53 grade of cement and the required quality of aggregates due to the remoteness of the project location.” Then there is the challenge to negotiate congested and densely populated village roads and railways to move heavy equipment for piling as well as concrete work, the constant hazard of working next to a busy, running railway track, and working in islands between railway tracks to safely construct the rail over bridge spans.

The project team has adopted a wide array of digital solutions to drive efficiencies including IoT for weighbridge transactions, concrete production of the batching plants, GPS on a host of vehicles like transit mixers, mounted cranes, wheel loaders, etc. “39 generators and a BG 25 piling rig are connected through IoT,” mentions Shekhar. “In addition, we also use WISA, Digitance for attendance, IB4U and QIR (Quality Incident Reporting).”

With two very prestigious and massive projects to execute, Tsn and team has a lot on their plate and here is wishing them the very best to deliver handsomely!