Indian subsurface construction requirements are unparallelled and through proper interventions, we can realise this dream. Dr Niranjan Swarup elaborates on the challenges and issues in trenchless applications in India and the solutions to overcome these challenges.
This is the second article in the trenchless technology introductory article series, being released by the IndSTT to sensitise construction industry stakeholders, engineering solution providers, members of academia and students, international trenchless equipment and spare manufacturers and also the service providers, both consultants and contractors. In this installment, we are starting from where we left in the first article and discussing various issues and challenges faced by the urban engineers and managers in the way of sound successful trenchless technology applications and possible ideas for resolving them.
Challenges faced by subsurface engineers applying trenchless
In the first article of the series, we had discussed the importance, benefits and the demand trends of trenchless technology in India. On its foundation, in the second article of this series, we are now discussing issues and challenges in proper application of trenchless technology in India and related ideas to resolve those issues. Subsurface strata, both in urban and rural regions will continue to get populated with each new structure being built and the challenges would continue to grow with population. A progressive engineer or manager would be the one professional who would continue developing oneself and one's environment to make a system capable of solving problems with ease and efficiency. For the uninitiated or those who are joining us from this article, let us revisit the first article of the series briefly.
As discussed in the first article, trenchless techniques from applications point of view could be categorised into three groups: new installations, rehabilitation, and replacement. First group includes techniques used to create subsurface lined cavities remotely, second group includes techniques used to strengthen the liners of subsurface cavities remotely and third group includes techniques to replace the liners, again remotely. For remote execution of these work, it is essential that the executioner is aware of the real condition at all such locations of work on real time basis. For new installation projects, this is gathered through the processes of Subsurface Utility Engineering (SUE). For rehabilitation and replacement work, it is Pipeline Condition Assessment (PCA). The rationale behind this grouping or classification is to provide a decision matrix for the applicator to evaluate the site and project requirements, and apply the most suitable working method.
Issues and challenges for trenchless ingress
Though trenchless is one of the most important tools for developing, maintaining and managing subsurface infrastructure till date in India, it has a chequered application history. Even if for subsurface construction requirements, people may need its application; they either consciously try to avoid it or fail to apply it properly due to ignorance. Both ways, the application gets stymied, resulting in erroneous project work and failed projects if the error becomes considerably high. The need of the day is to address this situation by identifying constraints and finding their solutions. Let us start investigating the current scenario to identify the issues needing resolutions.
Based on our analysis of the Indian trenchless market, issues constraining the growth of trenchless generally include:
All the above issues contribute in impeding the growth of trenchless to varying levels. Some would make the acceptance difficult, whereas some will ensure that it is completely rejected. The root cause of these issues or fears could be due to the requirements of more precise equipment and higher skill levels in trenchless applications. However, with these impediments in play, trenchless penetration in the construction industry gets restricted. This in turn limits the growth of equipment, personnel, service providers, and support infrastructure for trenchless activities and continues to keep the status quo.
An interesting case story covering these issues could be from New Delhi, where most of the above issues played their roles. Trenchless is to be applied for subsurface construction works while protecting the existing built infrastructure and natural habitat but any erroneous application may end up damaging the very same protected structure. To an untrained mind, the situation would suggest to shun trenchless and embark upon age-old tried and tested construction methodologies as is being witnessed off late. One such example is the happenings during the monsoon season; a few years back, where a large number of cave-ins occurred over a very short period of time in New Delhi. On closer scrutiny, it was discovered that most of such cave-ins were the results of collapse of sewer lines, triggered by accidental puncturing by drilling heads of HDD machines operating close by. The first knee-jerk reaction of works department engineers post such discovery was to stop permitting drilling in the vicinity of any buried pipeline. But that solution had a very short life as it had to be withdrawn in no time at all, as after stopping trenchless, the only viable alternative left to them was to excavate existing surfaces and destroy more structures.
The solution was rejected by most of the stakeholders, which ensured trenchless applications to continue. It must be understood that such approach would never be a solution for improper or erroneous installation activities. With a view to great and accelerating urban demands facing the city managers of the day and also of the future, trenchless has to be the future. The more the demand, higher the congestion of our subsurface space, leading to greater requirement of trenchless. But if this requirement is ignored, the pace of development slows down and the secondary costs escalate. For example, utility shifting is a critical part in a flyover construction project. Options available to project owners are either conventional or trenchless. Should the trenchless method be rejected to save money, the risks of the entire project delay would grow in case conventional methods fail, whatsoever may be the reason. This rejection in such a case would cost much more than the savings. As professionals, we need to have thatvision and ideas.
Ideas for solutions
Every problem, issue or challenge always has a solution. When we feel the problem is insurmountable, we are in fact acting with myopiaû the shortsightedness of our thinking capabilities. The need is to remove that mental myopia, look around, try to see what is the real problem and what could be the solution. That way, we can intervene in a stagnant sector and make it vibrant. Indian subsurface construction requirements are unparallelled and through proper interventions, we can realise this dream.
Successful interventions that will change the Indian trenchless industry could be by modelling and replicating the success stories from across the world. For example, one of the nations on the forefront of trenchless application is the US. It would be a good idea to analyse the state of trenchless technology research, publications and education and chart our course of action. We have invited Dr Mo Najafi to deliver a keynote address on these issues in the forthcoming No Dig India Show 2018 (NDIS) at Mumbai. Also, we have invited 10 more international experts to follow the suit as keynote speakers.
Another intervention is the provision of a discussion forum. In NDIS, a round table is scheduled where different city engineers would be discussing their issues and problems with experts for solutions. It is expected that this intervention would go a long way in resolving sticky issues, sharing the information, database creation and accelerating the ingress of trenchless in smaller cities.
Next intervention is the standardisation. All misgivings or apprehensions could be removed by standardising the work quality, costs and other related outputs. This would mean standardising the specifications, technique deliverables, working methodologies, measurement units and rates. IndSTT is releasing the 11th edition of the Schedule of Rates for Trenchless Technology in NDIS to continue cost and technique deliverable standardisation. In the same event, next editions of the codes of practice for five major techniques will be released and also two new codes would be released. In the next article of this series, we will be covering points linked to Advancing Trenchless Standardisation which is the theme of the NDIS this year.
We have listed a few issues and challenges facing the trenchless applications in India. Most of these issues are being addressed through focussed actions that IndSTT is taking. However, assistance of the engineering fraternity could provide the much required shot in the arm.
Dr Niranjan Swarup is the Director General of Indian Society for Trenchless Technology (www.indstt.com), the apex organisation of trenchless industry in India.