Tuesday, July 29, 2008

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.

Thursday, July 24, 2008

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.”

Tuesday, July 15, 2008

Roctest Introduces New SensCore System


Roctest Ltd. announced the introduction of the new SensCore product line, dedicated to the monitoring of corrosion in reinforced concrete structures. The SensCore system is a wireless sensor network, designed to detect and predict the onset of steel corrosion in concrete. The system consists of sensors, dataloggers and a measurement hub that concentrates the data from several dataloggers and transmits it to a central database, where it can be accessed by the authorized users. The sensors are able to measure several parameters, which are critical to evaluate the present and future risk of rebar corrosion in concrete. In particular the corrosion current and the concrete humidity are measured at several depths between the concrete surface and the rebar depth, to analyze the progression of the corrosion front as well as evaluate the performance of hydrophobic coatings.
The sensors are extremely simple to deploy and can transmit their data wirelessly to the measurement hub, thus eliminating the need to install any wiring in the structure to be monitored. Because of its modular design, this system is adapted to structures of all sizes, from a small overpass to a long tunnel and can be installed in both new and existing structures. The SensCore system integrates seamlessly with all present Roctest, Télémac and SMARTEC product lines, based on electrical, vibrating wire or fiber optics technologies. It is therefore possible to combine several technologies in order to implement an optimal monitoring network for any type of structure, being it a bridge, a building, a tunnel, a dam or any other concrete structure. The SensCore System ties into Roctest’s SDB database system, providing a unified
display and interface to all monitoring data, regardless of the underlying sensing technologies.
The SensCore system has been developed in cooperation with a leading Swiss University and has already being deployed on tens of structures, including the I35 St. Antony Falls Bridge in Minneapolis recently instrumented by Roctest. “Corrosion is one of the leading concerns in reinforced concrete structures and often limits their durability” said Daniele Inaudi, Roctest’s CTO, “it is therefore advantageous to complement the current monitoring strategies with a direct measurement of the corrosion progression”.
“The SensCore system ideally expands our growing toolbox of sensing systems” added François Cordeau, Roctest’s CEO, “further positioning our Company as the leading provider of Structural Health Monitoring solutions”.

Monday, July 14, 2008

Bridge Doctors Podcast

Structural engineer Michael Todd describes the state of bridge monitoring around the world in this podcast. Interview by Rima Chaddha. Edited by David Levin. 
[NOVA]

Thursday, July 3, 2008

Roctest wins contract for Jinping 2 dam in China


Roctest Ltd.  and its Chinese agent, Earth Products China Ltd, have been awarded a major contract for the deliveries of numerous instruments for the second highest dam in the world, Jinping 2 HPP, located on the Yalong River in China. The project started in February 2007 and is scheduled to be completed by 2014. Roctest is the main supplier of geotechnical instrumentation for the project, which is part of a network of five dams along the Yalong River, including the Ertan Dam , which was also instrumented by the Roctest Group between 1995 and 2000.
“We are very proud to have won another prestigious contract in such a highly competitive market. This not only demonstrates our ability to meet stringent requirements but also to offer a complete solution to a very complex engineering structure,” said Francois Cordeau, President & Chief Executive Officer of Roctest. “Roctest is the only instrumentation company offering a complete toolbox of solutions, providing world-class traditional vibrating-wire instruments, leading edge fiber optic sensors, the unique SensCore concrete corrosion monitoring system and the application software to monitor complex structures,” added Mr. Cordeau.
With a height of 305 meters, this concrete dam will be the second highest in the world, after the Rogun Dam, in Tajikistan at 335 meters high. The total capacity of Jinping 2 will be 4800 MW, with its eight generators at 600 MW each.
This project will require thousands of sensors, a magnitude rarely seen in the industry, and will measure different parameters such as pore pressure in the foundation of the dam, settlement, strain and other types of movement during construction and all along the lifespan of the structure.