Roctest Announces New Contract for the Nam Ngum 2 Dam

Roctest Ltd, a leading manufacturer of sensors for civil engineering and industrial applications, announced it has been awarded the contract to supply market sensors and high precision measuring instruments for the Nam Ngum 2 dam in the Lao People’s Democratic Republic. This, the second dam on the Nam Ngum artificial reservoir, is being constructed with rockfill and a concrete face. Standing nearly 200 meters high, it will contain at least 250 high precision measuring instruments. The project manager selected Roctest due to its unique and fully integrated product offering combining different technologies. A fiber optic system will be installed to detect water infiltration at the joints between the dam wall and the rock faces while traditional vibrating wire technology will be installed within the dam’s structure.

“Our recent success in winning business from existing and new clients is a result of our unique product offering which combines vibrating wire and fiber optics technology and differentiates us from our competitors,” said Francois Cordeau, President and CEO of Roctest.

Roctest Press Release [Roctest]

Weigh-In-Motion system for Stonecutters Bridge

International Road Dynamics Inc said it was awarded a contract by Lucky Engineering Co. Ltd. in Hong Kong to supply and install a Weigh-In-Motion system for Bridge Monitoring/Protection on the Stonecutters Bridge in Hong Kong. 

IRD's total contract value is approximately C$806 thousand. The bridge construction and Weigh-in-Motion installation are to be completed by the end of June 2009. 

SHM Shows Savings Potential in Excess of 30%

LifeSpan Technologies, announces the availability of its second White Paper that describes a simple four step process, allowing repair and replacement bridge projects to be based on risk priorities and precise engineering data.

If Congress were to implement this proposed process, bridge cost savings at the federal and the state level could be in excess of thirty percent. Federally mandated visual inspection techniques have been used on bridges for over 35 years. The Federal Highway Administration acknowledges that the visual process produces results that are subjective, highly variable and not sufficiently reliable for optimal long-term bridge management. Because of the inherent variability, allowing visual inspection assessments to control bridge repair and replacement projects can lead to significant unnecessary expense.

"Our proposed process, calling for the use of proven condition assessment technologies, can easily provide billions of dollars in savings," commented Peter Vanderzee, CEO of LifeSpan Technologies. "In this era of severely limited federal and state funding, we are convinced that every bridge classified as structurally deficient, or that has a sufficiency rating less than fifty (the threshold for replacement), should have a technically appropriate advanced condition assessment solution deployed prior to repair or replacement funding authorization."

Adopting advanced condition assessment technologies is the most effective means for DOTs, railroads, toll roads, counties, cities and other bridge owners to gather the crucial information on structurally deficient bridges to more accurately diagnose deficiencies, define safe operating parameters, and objectively plan/prioritize repair projects. Advanced bridge monitoring systems can help keep the traveling public safe and provide information which can be used to optimize long-term bridge management.

The White Paper can be ordered by emailing whitepaper@lifespantechnologies.com 

[Insurance News Net]

Roctest announces new orders for fiber optic sensors

Roctest Ltd, a leading manufacturer of sensors for civil engineering and industrial

applications, today announced Smartec, the Company’s subsidiary for structural health monitoring (“SHM”) recorded $1.3 million in new orders for projects in the civil engineering sector and infrastructure monitoring, including $220,000 to instrument one of the tallest communication towers in the Middle-East. 

Roctest Press Release [Roctest]

Sensors Deliver Real-Time Info on New Minnesota Bridge

Using a complex array of more than 300 sensors, engineers say they can now remotely monitor the structural health of the new I-35W bridge in Minneapolis. The concrete bridge, which replaces the steel spans of the old bridge that collapsed and killed 13 people in 2007, incorporates sensors in the foundation elements, sub-structure columns, main span, box girders, expansion joints, bridge deck and bearings. The bridge's engineers, Figg Engineering Group, Inc., say they outfitted the new structure with the sensor system because they wanted to monitor its "health" and because they wanted to participate in advanced engineering research on the new structure with the University of Minnesota's Institute of Technology.

"It's unusual to do this on a new bridge, even today," says Alan Phipps, design manager for the I-35W project at Figg Engineering. "Structural health monitoring systems are typically applied to older structures." Figg outfitted the new bridge with at least six different types of sensors. In all, the company embedded 323 sensors, including: vibrating wire strain gauges in the concrete; temperature sensors on the top of the bridge deck and on the underside of the bridge; accelerometers to measure forces near the center of each box girder span; long-gauge strain gages in the main span; linear potentiometers to monitor movement of the expansion joints and bearings and embedded corrosion sensors to monitor corrosion to the reinforcing bars at various depths of the concrete.

"Minnesota uses a lot of salt, so the top 2.5 inches of the wearing surface is intended to be replaceable," Phipps says. "It's like the shingles on your house; eventually you have to put a new roof on.". Figg worked with sub-contractors to outfit the bridge with the sensors. Roctest Telemac provided wire strain gauges, temperature sensors and corrosion sensors. Accelerometers came from Minnesota Measurement Engineering.

Engineers can monitor the strains in the bridge in real-time over the Internet. All 323 of the sensors are connected by wire to a central computer, which collects data and stores it. The sensors made their debut recently when the Department of Transportation placed eight 25-ton trucks in various patterns atop the bridge deck and then monitored strains on the central computer. University of Minnesota engineering professors are said to be interested in examining the effect of temperature differentials between the top of the bridge – which can be exposed to sunlight – and the structure's underside, which is in the shade and faces down at the river below.

"This is just a way of starting off on the right foot with this new bridge," Phipps said. "It provides information on how to maintain the bridge, starting with Day One. We think this kind of structural health monitoring is going to become more and more common in the future."

[Design News]

SHM Research at University of Michigan

Professor Jerry Lynch, in his lab at the University of Michigan Laboratory for Intelligent Structural Technology in Ann Arbor, holds up a sensor that can help detect damage to a bridge before it becomes visible.

"We're aware that bridges are really difficult to maintain over their life, and we're sensitive to that," said Jerry Lynch, U-M professor of engineering and author of a paper on the research.

"But what we'd like to do is give (inspectors) a way to monitor those structures in a better way."

Lynch helped develop a structural coating, made of carbon nanotubes, that uses electrical currents to find damage like strain and corrosion. The idea behind the coating technology is to avoid catastrophes like the August 2007 collapse of the I-35 bridge in Minneapolis, Minn., that killed 13 people. The recent one-year anniversary of the collapse has again drawn attention to bridge safety and monitoring techniques. Faulty design is being investigated as the cause.

"These sorts of failures are very intimidating psychologically. It sort of violates that notion of terra firma," Lynch said. " ... Bridges are not supposed to fail." The breakthrough sensing skin is made of layers of the nanotubes mixed with polymers, and is sprayed as a permanent coating on the structure. A carbon nanotube is microscopic and shaped like a long, hollow strand of spaghetti, said U-M engineering professor Nicholas Kotov, a key developer of the technology. 

It's one of the strongest materials available and, when mixed with the polymers, lends that strength to the coating. When technicians flow electricity through the skin, it produces a two-dimensional image via a central computing device. Electrical resistance shown in the image will indicate structural damage. The hundreds of micro-layers in the coating allow it to sense structural strain, corrosion, pH levels and other indicators of damage. The technology is the first to provide comprehensive data on the entire structure, Lynch said. In traditional bridge monitoring, engineers use data from points of concern, like the structure's joints, to calculate data for the entire bridge. The coating costs about $1 per square inch and is engineered to last decades, Kotov said. "Presumably the carbon nanotube coating won't corrode over the lifetime of the bridge," he said. The sensing skin is set to be tested in Korea or Taiwan next summer. Several Asian countries - particularly those in high seismic areas - are interested in the technology. The technology also is important to U.S. bridges, which are aging. In two or three years, the coating could be ready for commercial use.

In the meantime, Lynch has helped create wireless sensing devices to send bridge monitoring data more cheaply. One of his devices, although only a few inches in diameter, costs $100-$200. Data-sending cables could cost more than $1,000 a piece.

The wireless device, called the Narada wireless sensor, is already installed on 15 bridges worldwide, on a U.S. naval ship and on wind turbines in Germany.

Lynch said he hopes to be able to combine the sensing skin and wireless technologies "for use somewhere down the line." It's important to monitor the country's bridges to prevent disasters like the Minneapolis bridge collapse, Lynch said. And because most bridges fail slowly instead of without warning, sophisticated monitoring techniques are vital. "I think it's critically important, there's no doubt about it," Lynch said. "There's room for improvement when it comes to monitoring bridges. ... it's like medicine. There are always challenges out there."

[Ann Arbor News]

Clarkson University’s Sazonov Performs Bridge Experiments In Malaysia

Edward Sazonov, assistant professor of electrical and computer engineering at Clarkson University, recently collaborated with faculty from the National University of Malaysia (Universiti Kebangsaan Malaysia, UKM) to perform bridge experiments on location in Malasia. UKM sponsored Sazonov’s visit, which focused on wireless bridge monitoring technologies that he has developed at Clarkson with substantial funding from the New York State Energy Research and Development Authority (NYSERDA).

The task of structural health monitoring of highway bridges and overpasses has gained significant attention in recent years. Monitoring the health status of bridges is not only a matter of preventing economic losses from traffic delays and detours, but also an issue of preventing catastrophic failures and loss of human life as occurred in Minneapolis just a year ago. Unfortunately, this has become a worldwide problem as many countries recently have realized a significant increase in the number of aging bridges constructed 50 years ago and more.

Sazonov’s group has developed a wireless system, which provides utility similar to a conventional wired system, but does not need wires. The wireless sensors are capable of time-synchronous data acquisition and 100 percent data delivery in a scalable system that can include hundreds of distributed sensors. Sazonov’s research shows that synchronization on the level of microseconds is required for vibration analysis of highway structures. Sazonov’s system satisfies such stringent requirements and can serve as a platform for applications of structural health monitoring that use vibration.

The experiments in Malaysia followed earlier experiments in New York State in which 44 wireless sensors were deployed on a steel girder bridge. The goal of the joint experiments with UKM was to test the system’s applicability to different construction technologies and different environments. In the experiment, the sensor network was installed on a pre-stressed concrete bridge. Then, the vibration response of the structure, due to passing traffic, was analyzed to provide information useful for damage detection.

The results of the experiments demonstrated that the system can be deployed successfully on structures constructed using different technologies. This was good news to Muhammad Fauzi Mohd Zain, who is deputy dean and co-director, Advanced Engineering Centre, Faculty of Engineering at UKM and Sazonov’s Malasian host. "In Malaysia, commonly we use visual inspection routinely to detect small cracks or defects. It is like finding a needle in a haystack and impossible in areas that are inaccessible or hard to access," said Zain. "Gradually such constraints are being overcome with emerging new technologies... for vibration based monitoring of structures."

[Clarkson University]

Bridges on I-80 monitored for stress, strain during move

Sensors that dotted and crisscrossed the seven bridges that were lifted, driven, launched and lowered into place along I-80 have told officials in charge of the project that the structures responded as they were designed to.

In past bridge projects around the nation, prefabricated decks haven't been lifted and transported to the extent the replacements along I-80 were, so monitoring the integrity of the structures was important, Utah Department of Transportation officials said.

"We had real-time data during the moves that let us monitor the stress and strain on the girders and the bridge deck," said Shana Lindsey, director of research and bridge operation for UDOT. "The sensors allowed us to see if we went beyond the tolerance levels of the materials, and we didn't."

As each bridge moved from the farm to its final location, 28 long-strand fiber optic sensors sent out more than 100 readings per second on the state of the structure. In real-time, a crew of engineers and specialists analyzed the data on-site to gauge the strain on points of stress for each portion of the transport. The readings alerted the observers to potholes or bumps in the route, telling them how the bridge responded.

"If you can pick up the movement of a structure while they're still in their embryonic stages, you can prevent repairs and problems before they happen," said Tom Winant, vice president of technical sales and marketing for Osmos USA.

The bridges were designed to allow for up to three to four inches of deflection on either end and still be able to return to their original state, Lindsey said. According to the sensors and the analysis of engineers, the bridges did not deflect to those levels, but some hairline cracks did appear on the structures.

The cracks were expected, though, because it is concrete's nature to crack even without being transported, Lindsey said. To prevent salt and water from entering into the cracked areas, UDOT has scheduled a polymer overlay to coatthe structures to protect them from early erosion or deterioration.

Lindsey said the massive amount of data compiled from each move will help UDOT refine its techniques and designs for future projects.

The results from the move verified the assumptions designers made when they began fabricating the bridges and planned the launch, said Roy A. Imbsen, an engineer and consultant to the project. With the data, Imbsen said UDOT would be able to implement specifications to the accelerated bridge construction process so other agencies could begin to use it, too.

[Desert News]

New Minnesota laws on Bridge Inspection

Four DFL lawmakers stood before the press and proposed a 10-point package of bridge safety reforms that they say is a first step toward a bill they will introduce during next year’s legislative session.

The package has been in the works for weeks, and is in direct response to reports and recommendations contained in two independent studies on bridge safety that have been concluded in response to the I-35 bridge collapse last August — by the Office of the Legislative Auditor in February and the law firm of Gray Plant Mooty in May. But the harrowing incident over the weekend — in which a six-foot-by-nine-foot slab of concrete tore away from the underside of Maryland Avenue and fell into Highway 35E, damaging two vehicles and snarling traffic for eight hours — added urgency and gravitas to the legislators’ recommendations.

Among the more prominent recommendations set forth on Monday was the necessity for bridges to be inspected at least every 12 months, and the setting and followup of specific performance targets at MnDOT, including the stipulation that an analysis be done by the agency whenever any of their goals or forecasts aren’t met. The package also recommends that the state salary cap be lifted for MnDOT engineers in order to assist with recruitment and retain quality personnel, and that either the commissioner or deputy commissioner of MnDOT be a professional engineer.

Read more here. [minnesotaindependent.com]

US Sweeping bridge safety bill includes fiber optic

U.S. Rep. Steven C. LaTourette (R-Bainbridge Township) today announced that a sweeping bridge safety bill approved by the House includes a study of fiber optic sensors like those developed by companies with offices in Twinsburg and Mentor that can detect stresses on bridges before they collapse or fail.

The House of Representatives today approved H.R. 3999, the Highway Bridge Reconstruction and Inspection Act, by a vote of 367-55. LaTourette said the measure authorizes $2 billion over two years for bridge reconstruction nationwide and requires the Federal Highway Administration (FHWA) to update national bridge inspection standards. It also calls on the FHWA to improve training for highway bridge inspectors. The bill was introduced after the August 2007 bridge collapse in Minneapolis that killed 13 people.

LaTourette said the bill includes language he supported that will authorize the FHWA to study the effectiveness of fiber optic sensors and other sensors in detecting deficiencies in bridges, particularly those under construction or renovation. LaTourette said he believes fiber optic sensors marketed by companies in Twinsburg and Mentor might have detected extreme stresses on the 35W Bridge in Minneapolis before it collapsed. It was loaded with heavy equipment and traffic had been shifted to accommodate construction, he said.

LaTourette said two 14th District companies are marketing cutting edge products that might have been able to avert the tragedy in Minneapolis. Cleveland Electric Laboratories Co. in

Twinsburg is marketing fiber-optic sensors that are attached to bridges to detect and monitor stress loads, and its product is being used on a project in Albany, NY. Roctest Ltd. of Quebec, which has its U.S. office in Mentor, is also marketing a fiber optic sensor system to detect stresses on bridges, and it will be used as the 35W Bridge in Minneapolis is rebuilt.

“We’re lucky that inspectors almost always catch problems and avert tragedies, but there are situations where unusual stresses on a bridge can lead to catastrophe. I think this technology

certainly merits more study so we never experience another disaster like the one in Minneapolis. It’s exciting to have two Northeast Ohio companies right in the mix,” LaTourette said.

LaTourette said construction can place unusual stresses on a bridge, and the small fiber optic sensors can monitor and record the level of stress.

“Who hasn’t been on a bridge where all the traffic is shifted to one side while the other is filled with workers and heavy equipment?” LaTourette said. “If a tiny sensor can detect when stress becomes so great that it makes a bridge susceptible to collapse, that’s a tremendous safety benefit not only for motorists but the workers renovating the bridge.”

[latourette.house.gov]