A passionate ambassador for the trenchless industry, Dr Samuel Ariaratnam is the Immediate Past Chairman of the International Society for Trenchless Technology (ISTT), a Professor, a Construction Engineering Program Chair at Arizona State University, and is on the Executive Committee of the American Society of Civil Engineers’ new Utility Engineering and Surveying Institute.
The explosive danger of cross bores
Dr Ariaratnam’s current research interests and focus areas are diverse.
One initiative he is particularly involved with in North America is the important and extremely dangerous issue of cross bores.
“Cross bores involve sewer laterals or assets that are connected to buildings or houses and are typically non-metallic and very difficult to locate,” he told Trenchless Australasia.
“A small gas distribution main is then unknowingly installed through this asset, thereby “÷crossing’ or “÷bisecting’ it. Years later, the blocked asset backs up. A sewer guy or plumber is then called, who comes in with a mechanised tool and puts it down the toilet and through the asset. They then nick the gas line and can blow up the building.”
To raise awareness of the dangers of cross bores for the trenchless community and elsewhere, Dr Ariaratnam has been working with organisations such as the Distribution Contractors Association to produce position papers to bring the issue to the attention of government agencies such as the United States Congress.
According to Dr Ariaratnam, the issues first arise within the legislation for the responsibility for locating sewer laterals, which is stipulated as being either “the owner or operator of the sewer lateral”.
“The word “÷or’ is a big problem,” explained Dr Ariaratnam. “The owner is the homeowner, but the operator is the utility that is getting the revenue from the sewage. So because of the word “÷or’, you can’t expect the homeowner to find a way to locate an asset beyond using a Dial Before You Dig service, and then the utility says “÷well, we don’t know where it is and we’re not going to locate it because we don’t have to, thanks to this word “÷or’.”
This stalemate is worrisome for gas utilities, he continued. “We have what we call ticking time bombs. There are a lot of laterals out there in North America that have been bisected – we just haven’t hit them yet, or they haven’t backed up yet.”
To stave off a potential disaster, Dr Ariaratnam is helping to raising awareness amongst plumbing and “÷rotor rooter’ contractors.
The initiative is large in scope, with Dr Ariaratnam working on it for the better part of a decade.
“We try to tell them – before you go in with a mechanised tool, put a CCTV camera down there. That way, you can see if it’s just a blockage or is indeed a cross bore.”
A drill in the right direction
Another field of concentration for Dr Ariaratnam is the HDD sector, which has evolved in leaps and bounds over the past decade and a half. So much so, in fact, that Dr Ariaratnam credits the innovation of the HDD manufacturers with playing a significant role in bringing down the costs of trenchless installations.
“An HDD rig from 15 years ago is much different from a rig today,” said Dr Ariaratnam. “It is both quicker and more efficient, allowing projects to be completed faster without sacrificing accuracy. Since time is money in construction, this also reduces costs.
“These advances have not been limited to the HDD rig itself – the locating equipment and other supporting innovations have also been tremendous.”
However, innovation alone is not the full story for the lowering costs of trenchless installations, continued Dr Ariaratnam, noting the sector’s competitive spirit as another crucial ingredient.
“Part of the decreasing costs is simply the fact that there are more contractors out there doing trenchless projects, making it a more competitive market.”
That said, Mr Ariaratnam remains impressed by the larger diameters and longer distances being achieved on HDD projects.
“Some examples approach up to 4 km in length. These boundaries and capabilities are going to continually be pushed so it will be interesting to see what the HDD industry can really do.”
Trenchless: the way of the future
Looking to the future of the trenchless industry, Dr Ariaratnam noted “the sector will continue to grow well after I’m gone”, with the technology poised to be the way of the future.
“The myopic thinking will change and it will become trenchless first and other options second. Compare this to the current status quo, which is “÷open cut first, but maybe we can do trenchless’,” he said.
Dr Ariaratnam also noted the unceasing progression of growth in the industry, combined with the presence of a huge market and opportunity for expansion.
“Trenchless is currently less than ten per cent of underground construction compared to open cut. And if you are less than ten per cent, then there is just a tremendous amount of market share to capture.”
Ultimately, Dr Ariaratnam recognises the input and collaboration of his peers, who together have helped develop the technologies and techniques to really grow the trenchless and no-dig industries.
“There are a lot of very smart people in this industry from all sectors,” he concluded.
“I’ve been involved in the trenchless industry since 1996 and almost 20 years later it is just leaps and bounds ahead. I’m so proud of this industry and the people that are involved in all corners of the world.
“When I was Chairman of the ISTT I travelled to many countries and saw trenchless in so many places. It was very rewarding to see that the technologies are here to stay and are going to continue to grow.”