In the next in a series of interviews with prominent civil engineers, Janaki Krishnamoorthi meets Shyamkant Dharmadhikari, Executive Vice-President and Chief Technical Officer, HCC Group.

What do nuclear reactor Dhruva at Mumbai's Bhabha Atomic Research Centre (BARC); Kadamparai Pumped Storage Hydel Power Plant in Tamil Nadu; Chamera Hydroelectric Power Plant in Himachal Pradesh; Nathpa Jhakri Hydel Project in Himachal Pradesh; the Mumbai-Pune Expressway; and Mumbai's Bandra-Worli Sea Link have in common? First, they are all landmark projects that are considered engineering marvels. Second, one man, Shyamkant Dharmadhikari, currently Executive Vice-President and Chief Technical Officer, HCC Group, was instrumental in their execution.

In fact, this highly acclaimed technocrat has been involved in the development of over 45 diverse infra projects (on shore, off-shore and underground) in his career spanning over three-and-a-half decades with the HCC Group, which includes Hindustan Construction Company Ltd, HCC Infrastructure, HCC Real Estate, Lavasa Corporation, Steiner SG and Highbar Technologies. He also has an impressive track record of completing projects on or ahead of schedule while maintaining the highest standards of quality. However, Dharmadhikari, a down-to-earth and unassuming man who hails from Jalgaon in Maharashtra, wears his reputation lightly, preferring to attribute his achievements to his learning from his seniors at HCC and teamwork. "I believe if you dedicate yourself totally to your work, success will follow automatically," he adds, asserting that HCC's professional excellence has made it all possible.

Dharmadhikari witnessed this professional excellence during a visit to Koyna Dam (a HCC project) in his school holidays - the experience changed his life forever. "I was fascinated by the huge size of the dam and the mighty river being tamed," he remembers. "That was the moment I decided to become a civil engineer. Further, I was impressed by the proficient style of functioning. That is when I decided that I would rather work for a private-sector company like HCC than get into government service, which was the trend at the time." After graduation, he landed up at HCC's head office in Mumbai and submitted his resume. A week later, he received his appointment letter.

When he joined HCC in 1975, he was immediately assigned as site engineer to a major project: BARC's Nuclear Reactor 5 (Dhruva). Since then, there has been no looking back for Dharmadhikari, who has gone on to execute a gamut of projects ranging from highways, roads and hydroelectric power plants to nuclear power plants and sea links, though a majority have been in the hydropower sector. He has also rapidly climbed up the corporate ladder at HCC; since March 2011, as executive vice-president and chief technical officer, he has been advising and guiding the HCC Group on critical technical issues related to infrastructure projects.

Today, at the age of 60, after having handled almost every kind of infra project, Dharmadhikari nurtures a desire to build a huge dam like Koyna in Maharashtra or Idukki in Kerala, something he is yet to do. Meanwhile, his plans for the future include sharing his experience with the younger generation of civil engineers and students, and writing books on modern technologies in construction, particularly in the area of concrete and tunnelling, his pet subjects. He shares his views on his profession in an interview with CW...

Tunnelling travails: I have spent 22 years of my career working underground. Tunnel excavation is complex as it deals with uncertainty. Geotechnical analysis gives you some idea about types of rock, weak beds, shear zones, etc. But only when you go underground will you know what's in store. Tunnel engineers must have the capacity to quickly ascertain the rock condition, stand-up time, method to use for excavation, the strength of the explosives to be used if required, etc. Various natural conditions like excessive water seepage and high temperatures have to be countered too. For instance, in the Nathpa Jhakri project, the whole tunnel was filled with hot water with a temperature of 60°. We provided coolers throughout the tunnel and kept supplying workers with cold water, saline water and juices. Tunnelling also poses a risk to life as the threat of cave-ins, flooding and fire always loom large.

Technological progress: Earlier we used to only read books or watch films about the technologies used in building the Brooklyn suspension bridge and London Metro, or tunnelling in weak rock. Today, all these technologies are being used in Indian projects. And working shoulder to shoulder with international experts on such technologies is a great experience. There is a higher degree of mechanisation now as changes in regulations have made import of machinery easier. In short, globalisation has broken the barriers, leading to exchange of technologies and raising construction standards in India.

Tunnelling technology: Non-blasting technology deployed in excavation has made significant contribution to tunnelling internationally. There are many methods included in this technology, such as excavation of tunnels by road headers, tunnel boring machines, and deploying hydraulic pressures. Non-blasting technology permits excavation of the tunnel even in populated areas, in the midst of a city and areas where drilling and blasting is not feasible. Depending upon the suitability of the geology, a high rate of progress can be achieved by this method. It is expensive but the higher cost can be offset by savings in time.

Tunnel excavation by road headers as well as tunnel boring machines is a common scenario in India. However, Himalayan weak rock is not that suitable for tunnel boring machine operation. In southern India too, rock strength is very high and excavation by tunnel boring machine is not advisable.

The need for internship: We probably need an internship in civil engineering. As of now, we jump into the stream and then learn to swim. But I think much will also depend on one's willingness to learn and attitude to work. The difference between theory and practice exists in all fields, not just civil engineering. And it will continue to exist. For instance, there are thousands of books on concrete technology; yet actually producing quality concrete continues to be a big challenge. Today, many young engineers think that whatever they learnt in college is a waste and they have to learn totally afresh at site. This is not true because whatever you do at site is based on certain basics learnt in college. And without knowing the basics you cannot move forward.

Major projects:

• Nuclear Reactor 5, Bhabha Atomic Research Centre, Trombay
• Kadamparai Pumped Storage Hydel Project, Tamil Nadu
• Sardar Sarovar Dam Foundation Treatment, Gujarat
• Chamera Hydel Project, Himachal Pradesh
• Nathpa Jhakri Hydel Project, Himachal Pradesh
• Mumbai-Pune Expressway, Maharashtra
• Bandra-Worli Sea Link, Mumbai
• Delhi Metro, Delhi
• Dhauliganga Hydel Project, Uttarakhand
• Tirupur Road Works, Tamil Nadu
• Satara Kolhapur Road Works, Maharashtra
• Goshikurd Spillway, Maharashtra
  

Challenging projects:

Project: Mumbai-Pune Expressway, section B Chowk to Adoshi
Location: Maharashtra
Client: Maharashtra State Road Development Corporation Ltd (MSRDC)
Period: January 1998 to April 2000
Cost: About Rs 200 crore (at the level of 1998)

Background: The work involved construction of a new six-lane highway stretching to a length of 16.4 km in the difficult Ghat section with six major and two minor bridges, eight underpasses, four overpasses including embankments, culverts, drainage, pavements, crash barriers, etc.

Challenges: The biggest challenge was to complete the project on par with international standards and within 28 months. Of the 28 months, mobilisation took four months. As the area witnessed heavy rains during monsoon in the two years the project was underway, working during these months was not easy. In the first year only excavation was done during monsoon. In the second year concreting (PQC) on road was also carried out with sufficient protection. "When PQC was being laid, we literally covered the whole road with tarpaulin for protection against rains," recalls Dharmadhikari. "Getting the right grade of concrete was also challenging. Our team of concrete technologists worked day and night for two months to get the right quality mix. We had to lay the concrete from 10 pm to 7 am as it had to be poured at a temperature of 12-15° C. At the batching plant, the temperature was maintained by cooling the concrete with ice." In addition there were hurdles in execution owing to other regular issues like land acquisition, encroachments and quarrying. Yet the job was done, in time. "In short, we destroyed the myth that Indian contractors cannot construct roads on a par with world standards," says Dharmadhikari with pride. "Not just HCC, even other contractors who were working on the expressway did quality work."

Award: Dharmadhikari was conferred with the Outstanding Contribution to Concrete Technology 2007 Award for this project by The Indian Concrete Institute.

Project: Chamera Hydroelectric Power Project (power house and power tunnel)
Location: Himachal Pradesh
Client: National Hydroelectric Power Corporation Ltd  
Consultant: SNC Acres Inc, Canada  
Period: February1986 to March1993
Cost: HCC's portion of the total project was about Rs 75 crore (at the level of 1980)

Background: The project involved the construction of an underground powerhouse and power tunnel in a geologically complex region. For the first time in India, a new method of tunnelling, now well known as the New Austrian Tunnelling Method (NATM), was used for excavation.

Challenges: Aggressive rock conditions at site posed a major challenge in the power tunnel. "The rock comprised carbonaceous phyllites with water, which is the worst combination," elaborates Dharmadhikari. "And when we started working, we realised the geological situation was worse because of the foliations in the rock that were sometimes very adverse from the stability point of view. Even ultra modern machineries like hydraulic drilling boomers and hydraulic rock bolting machines imported from Canada proved ineffective."As a result, the tunnelling process slowed down. Against anticipated progress of 3 m a day per face of tunnelling, only around .5 m a day was possible. In the powerhouse, the rock stratum was so weak that the stability of the power house itself became a question. When benching began, the power house started ing. However using the Canadian technology and Austrian tunnelling method, the difficulty was overcome. Extensive pre-stressed anchoring was done to stabilise the rock surface because of the weak rock strata. "Another challenging situation was the 157 m vertically deep pressure shaft with 8-m diameter," adds Dharmadhikari. "It had a strike of shear zone throughout making excavation extremely difficult. There was also abnormal water seepage owing to the shear zone. A combination of conventional excavation method and NATM helped in successfully completing this part of the project. Chamera-I was a trendsetter not only in hydropower construction but the Indian construction history. Since then, the concept of hydropower projects has radically changed."

Award: The project won the Sarvamangal Award in 1994 for excellence in construction from the Association of Consulting Civil Engineers.

Project: Foundation treatment of Sardar Sarovar Dam
Location: Gujarat
Client: Public Works Department, Gujarat  
Period: January 1984 to May 1986
Cost: About Rs 12.5 crore (at the level of 1982)

Background: The foundation was weak and treatment had to be given through tunnelling based on the method adopted in the famous Itaipu Power Project in Brazil as the circumstances were similar. In both cases, it was a treatment for the weak rock layer/zone in the foundation of a major dam. The method involved piercing the weak rock zone through shafts excavated in a grid, then removing the weak rock by excavating through drifts and taking out the material through shafts. Later, the cavity created was filled completely with concrete, colcrete/colgrout. The fine gaps remaining at the junction of the hard original rock and concrete were filled with a thick grout. To ensure proper contact between the original rock and back-filled concrete, bore holes were taken at regular intervals.

Challenges: Tunnelling in itself is a complex task and doing it manually in weak rock is even more demanding. "The strength of the weak rocks is not constant and their behaviour cannot be correctly estimated in advance," explains Dharmadhikari. "As we had no idea about the thickness of the rock, tunnel size could not be fixed in advance. It had to be determined while we were on the job and hence the size kept varying." In tunnelling, there is also the risk of a collapse and flooding; carrying out the evacuation is another major challenge, which was also encountered here. Every year, the work halted on May 31 and the equipment was moved out and the shafts sealed. In 1983, the monsoon arrived early and because of heavy rains in the catchment area of Narmada one day in the last of week of May, the water level began rising. "Around 7 pm we got the message that our work site would be surrounded by water in four to five hours," remembers Dharmadhikari. "Around 2,700 people were working in the tunnel and we began evacuating them through the shafts. Unfortunately, after half an hour the power supply went off and the winches stopped working. Naturally, there was havoc as the tunnel was getting filled with water and boulders were also going inside with the water through the shafts. Then we began using our Khalasi/Riggers team [workers who move heavy machinery] to literally lift the workers out. After half an hour, the power supply came back, the winches started working and all the workers were evacuated. It was a miracle. The operation went on until early morning." However, the whole tunnel was filled with water and dewatering had to be done the next day before work could continue. Despite such challenges, the contract was completed on schedule.

Track record: Shyamkant Kalidas Dharmadhikari

• 1974 : BE (Civil) from College of Engineering, Pune
• 1975: Joined HCC
• 1976-2005: Worked in various capacities - from site engineer and project manager to project controller - on a large number of projects, including several landmark projects
• 2005-2007: Headed the Business Development and Tendering Division
• 2008-2009: Headed the Hydro Vertical Division and was responsible for operation and execution of 17 hydropower and underground projects
• 2010-2011: In charge of Business Development and Construction Solutions for HCC's entire construction business
• March 2011 to date: Chief Technical Officer SS

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