GeoSIG — through a strategic alliance with Dr. Farzad Naeim, an internationally renowned expert in structural health monitoring — can offer consultancy and turnkey solutions for structural health monitoring of all types of structures including high-rise buildings, public buildings, bridges, tunnels and other special structures.
Using the expertise of the highly respected Dr. Farzad Naeim, who boasts over 35 years' experience and publications ranging from textbooks to journal papers, you can have peace of mind that your structure is safely surveyed and the most reliable solution is specified.
GeoSIG, with more than 25 years' expertise in structural monitoring solutions, can fulfil the requirements of the most challenging structure. Click here to visit his Website, or look over the solutions leaflet to see what we can offer.
Our Solutions for Structural Health and Response Monitoring
GMS Series Recorders for distributed and hybrid systems
- CR-6 Series Modular Multichannel Recording System for central and hybrid systems
- A wide variety of high quality sensors to measure acceleration, velocity, displacement, strain, tilt and environmental phenomena.
- Software solutions with highly customisable options
What is Structural Health and Response Monitoring?
Structural Health and Response Monitoring is an innovative method of monitoring structural status and performance without otherwise affecting the structure itself. Structural Health and Response Monitoring utilises several types of sensors embedded in, or attached to a structure to detect exceedance of allowed performance criteria as well as identify and verify structural behaviour.
Why Structural Health and Response Monitoring?
- The strength and serviceability of a structure can be considerably reduced by natural or human-made events, and increased levels of use
- Utilising Structural Health and Response Monitoring systems, timely notifications about any potential problems can be generated and behaviour of the structure can be monitored.
- The emerging use of Structural Health and Response Monitoring especially in the last decade, is a result of the increasing need for the monitoring of innovative designs and materials as well as a better management of existing structures.
What are the advantages of Structural Health and Response Monitoring?
- GeoSIG Structural Health and Response Monitoring systems not only help reducing risks and costs, but also help avoiding disaster by its notifications which allows to initiate early damage detection and therefore helps saving lives as well as assets.
- In case of any evacuation of the structure due to a transient event (such as an earthquake), the system allows to rapidly evaluate the structural response thus provides a highly useful measure for decision making whether to allow the occupants back in or to initiate a more comprehensive inspection before doing so.
- The ideal GeoSIG Structural Health and Response Monitoring system provides you with on-demand information about your structure's measured features, as well as warnings concerning any exceedance detected. Therefore Structural Health and Response Monitoring also significantly reduces repair costs through early damage detection, making the monitored structure safer and increasing the cost efficiency of its maintenance.
- Structural Health and Response Monitoring can significantly reduce insurance premiums for those operating - or in charge of - the safety of infrastructure such as bridges, railways or tunnels.
- increased understanding of in-situ structural behaviour and decreased down-time for inspection and repair.
Case Study:Structural Monitoring - Tainan Railway, Taiwan
Tainan Railway, Taiwan
When the Taiwan High Speed Rail was being constructed (for what was the world’s fastest train at the time), planners knew that it would run approximately 345 km from Taipei to Kaohsiung, passing 14 major cities and counties and 77 townships and regions. One area of concern was its proximity to the Tainan Science-Based Industrial Park (TSIP), located in Tainan County, southern Taiwan. The TSIP was a new location for many vibration-sensitive high-tech factories.
As a high-speed and high-capacity rail line, the THSR causes induced vibration as it passes next to infrastructures, buildings and residential areas. GeoTech Engineering Consultant Co., Ltd., a company who focuses on automated, remote and integrated geotechnical instrumentation monitoring systems as well as the development of corresponding database management software, was assigned by TSIP to mitigate the vibration caused by the THSR at the science park to ensure the high-tech factories would not be affected by passing trains.
The vibration mitigation project consisted of two specific measures:
• stiffening the elevated guideway structure foundations in TSIP with foundation-stiffening blocks (FSB) that structurally link the pilecaps of the pile-foundations together in the longitudinal direction of the THSR alignment, and
• constructing an underground wave-barrier-wall approximately 30 m to the west and parallel to the THSR alignment.
Since the THSR trains were not operational before vibration mitigation measures were constructed, there were no train-induced free-field ground vibration measurements to be used for comparison with the data obtained after mitigation. Therefore, two sites were required for ground vibration measurement -- Site A, in the mitigated section, and Site B, in the unmitigated section.
A total of 14 GeoSIG instrumented recording stations, all from VE-13 Triaxial Velocity Sensors, were deployed for Site A, as well as 14 instrumented recording stations for Site B, to measure the ground vibration. Other GeoSIG technology aiding the project included two CR-5 central recorders, integrated into LAN, data center 1000SP permanent data recording, and GeoDAS software.
The measures were successful, and the THSR boasts trains that are among the fastest in the world.
Case Study:Structural Monitoring - FAST telescope - China
FAST radio telescope, China
The Eye of Heaven opened in July 2016. That was when construction was completed for the world’s biggest radio telescope: “Five-hundred-meter Aperture Spherical radio Telescope” or FAST, located in the Dawodang depression in Pingtang County, Guizhou Province, southwest China. Nicknamed “The Eye of Heaven” or “Heavenly Eye,” it is the size of 30 football fields and cost about 1.2 billion Yuan (£120 million). The project, under the auspices of the National Astronomical Observatories, Chinese Academy of Sciences (NAOC), aims to survey neutral hydrogen in distant galaxies and detect faint pulsars. In the first weeks of opening, more than 2,000 pulsars had already been detected. Researchers also hope FAST will improve the chances of detecting low frequency gravitational waves and help in the search for extra-terrestrial life.
Southwest China is a very seismically active region. Although the natural geography of the Dawodang depression where the telescope was sited makes it ideal for this purpose, the mountainous area is situated along several faults. This scientifically-important and costly project requires seismic and structural monitoring, both for the preservation of the telescope and to provide important data for researchers.
The NAOC entrusted this work to Earth Products China Limited, or EPC. GeoSIG Partner EPC is a total solution provider in all aspects of civil engineering testing products and is a proven leader its field. A GMSplus6 unit and five GMSplus units were installed on six cable-support towers dotting the circumference of the telescope, each with a height of 150 m. The seismograph recorders are self-contained instruments equipped with uninterruptible power supply, which provides more than 24 hours of autonomy. They use an “Intelligent Adaptive Real Time Clock” (IARTC) with self-learning temperature compensation, improving the accuracy of the RTC or TXCO significantly. The IARTC is able to synchronize with GPS or NTP to UTC timing to provide high timing accuracy. The instruments’ software processes data in real time. If triggered by a seismic event, GMSplus calculates a number of event parameters and reports them to a data centre immediately.
With our eyes on the heavens and our feet on firm ground, we can achieve anything. Another Solution using GeoSIG instruments and a capable Partner demonstrating that quality and reliability can also be cost effective.
Case Study:Structural Monitoring - Centre Block - Canada
Centre Block, Canada
Located in Ottawa, the Centre Block is the main building of the Canadian Parliamentary complex on Parliament Hill. It is one of the most recognized buildings in Canada. The Centre Block is listed in the CRHP (Canadian Register of Historic Places) both as part of a National Historic Site of Canada and as a Federal Heritage Building. According to the Canadian Seismic Research Network, a significant earthquake is probably Canada’s greatest potential natural disaster. For example, the 2010 Central Canada earthquake had a magnitude of 5.0, but because of its depth, the effects were more widely felt. People in Massachusetts, Michigan and Ohio in the United States reported feeling tremors.
Due to the civic and historical importance of the Centre Block, the mandate was to deliver and install a seismic vibration monitoring solution to enable National Research Council Canada -- the Government of Canada’s premier research and technology organization -- to monitor and record the seismic vibration of the Centre Block structure.
Our partner, Kompass Geo-Equipment, with a wealth of experience in providing end-to-end customised solutions, successfully fulfilled the requirements of this highly prestigious project. The solution consists of one GeoSIG CR-6plus Multichannel Central Recording System and 10 highly-sensitive AC-73 triaxial force balance accelerometers, complete with GeoDAS communication and data analysis software. Due to the expert handling of the project, Kompass received a letter of commendation for their work.
The installed solution offers reliable and continuous monitoring, providing real-time data that can be recorded continuously as well as providing data based on event detection. With its enhanced capabilities, the system offers a comprehensive range of statistical data such as mean, max, min, and peak values, as well as many other useful data as may be required by the client. GeoDAS, a proven data acquisition and evaluation package developed by Geo-SIG, complements CR-6plus providing highly flexible user-friendly capabilities, and graphical, analytical and reporting tools with configurable automation.
Another Solution using GeoSIG instruments and a capable Partner effectively showing that quality and reliability can also be cost effective.
Case Study:Structural Monitoring - Unit 4 reactor sarcophagus
Unit 4, Chernobyl, Ukraine
The Unit 4 reactor explosion at Chernobyl near Pripyat, Ukraine, happened on 26 April 1986, making news worldwide. A sarcophagus was built just after the accident with the aim of containing radioactive materials and protecting the structure, and an exclusion zone was created around the area to restrict access.
In 2010, a Ukrainian law came into effect stipulating that the nuclear power plant site is to be cleaned by 2065. As a first and major step toward that goal, NOVARKA was contracted to design and build the New Safe Confinement Structure which, once completed, would enable deconstruction of the damaged reactor by others to commence. NOVARKA is a joint venture by two French companies: VINCI Construction Grands Projets and Bouygues Travaux Publics. The new structure will further contain radioactive materials and protect the existing shelter from weather damage, and ultimately, it will allow work to begin on deconstruction of Unit 4 at some point in the future. The colossal structure (measuring 108 metres in height and with a frame weighing 23,000 tonnes) has a projected lifespan of 100 years.
The working environment at the site is indeed a challenge due to radiation, but that is not the only concern. Ukraine does experience seismic activity, and the sarcophagus over the reactor has weathered over the years and is in danger of instability. NOVARKA needed a system to monitor strong ground motion. This is further exacerbated by the icy conditions.
Due to the scale and scope of the project, the best solution for monitoring strong ground motion was agreed to be a specially customised SMS system with special GeoDAS-NPP version, along with 2 x CR-6plus units with a combined 30 channels, 10 x AC-23-NPP (accelerometers) with special stainless steel housing (four of which were also externally shielded with a specially-constructed lead armour so that they could be placed inside the containment area), and cables and accessories.
The sensors are installed on selected structural members of the confinement shelter arch and its foundations, as well as at a freefield location for reference. Monitoring is performed locally (on site), but there is also the possibility to interact remotely by an authenticated user. The provided system has functions like: detecting seismic events, monitoring the response of the structure to seismic event, detecting abnormal vibration of the Main Crane System bridges during operation, and providing an alarm in case of exceedance of thresholds.
The installed solution offers reliable and continuous monitoring, providing realtime data that can be recorded continuously as well as providing data based on event detection. With its enhanced capabilities, the system offers a comprehensive range of statistical data such as mean, max, min, and peak values, as well as many other useful data as may be required by the client. GeoDAS, a proven data acquisition and evaluation package developed by GeoSIG, complements CR- 6plus providing highly flexible user-friendly capabilities, and graphical, analytical and reporting tools with configurable automation.
Another Solution using GeoSIG instruments, demonstrating that quality and reliability can also be cost effective.
Case Study:Structural Monitoring - Second Penang Bridge - Mal
Second Penang Bridge - Penang, Malaysia
The Second Penang Bridge is a 24 km bridge linking Penang Island to Penang in mainland Malaysia. The E28 expressway crosses the dual carriageway toll bridge, which is 30 m above water. It’s the second link to Penang Island after Penang Bridge. Construction began in November 2008 and was completed in February 2014, with the opening ceremony on 1 March 2014.
The Second Penang Bridge is the longest bridge in Malaysia. Although the Malay Peninsula is located on a stable part of the Eurasian Plate, according to historical records the earthquakes that influence the Malay Peninsula originate from two earthquake faults: Sumatran subduction zone and Sumatran fault. For the safety of bridge users and as protection of such an investment, the firm responsible for the bridge wanted a structural health monitoring system (SHMS). The SHMS is used for disaster control, structural health management and data analysis. There were many considerations before implementation which included: force (wind, earthquake, temperature, vehicles); weather (air temperature, wind, humidity and precipitation); and response (strain, acceleration, cable tension, displacement and tilt).
Such a high profile project required a company with extensive background in this area. Our Partner in South Korea, EJtech, focuses on top-level civil engineering, measurement, surveying, assessment and instrument sales. They have been successfully implementing solutions for their clients since they were founded in 1994. The SHMS they implemented included instrumentation from GeoSIG: 10 x GMSplus measuring systems with GPS receivers, 2 x CR-6plus modular multichannel recording systems with GPS receivers, 26 x AC-72-HV biaxial force balance accelerometers, 9 x AC-72-H accelerometers, 1 AC-73 accelerometer, and GeoDAS software.
Another Solution using GeoSIG instruments and a capable Partner effectively showing that quality and reliability can also be cost-effective.
Case Study:Structural Monitoring - Paks NPP, Hungary
Paks NPP - Paks, Hungary
Located 5 km from Paks, in central Hungary, the Paks Nuclear Power Plant is the first and only operating nuclear power station in Hungary. It has four reactors that produce more than 50 percent of the electrical power generated in the country and meet more than 40 percent of the country’s electric consumption.
The Paks NPP was designed to have a 30-year lifetime, but feasibility studies had shown that with some minor repairs and replacements, it was in a very good condition to extend its lifetime. Following the Fukushima I nuclear accidents in March 2011, Hungary’s government said it would conduct a stress test on the Paks Nuclear Power Plant to assess safety, but it wouldn’t abandon plans for lifetime extension and it would also go ahead with plans for its expansion. Unit 1 was granted a license-extension to 2032 in 2012, unit 2 to 2034 in 2014, and unit 3 to 2036 in 2016.
ChallengeWhile the applications of ionizing radiation bring many benefits to humankind — ranging from power generation to uses in medicine, industry and agriculture, ionizing radiation can also be harmful unless it is properly controlled. Industrial irradiators produce very high dose rates during irradiation, such that a person accidentally present in the radiation room could receive a lethal dose within minutes or even seconds.The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) establish the basic requirements for protection of people against exposure to ionizing radiation and for the safety of radiation sources. There are four general categories of gamma irradiator, defined on the basis of the design of the facility and, in particular, the accessibility and shielding of the radioactive source.- Category I means gamma irradiators (i.e. self-shielded irradiators)- Category II panoramic dry source storage irradiators- Category III underwater irradiators- Category IV panoramic wet source storage irradiatorsIrradiation facilities should be designed to meet the requirements established in paragraphs 2.24 and 2.25 of the BSS.According to “Radiation Safety of Gamma, Electron and X Ray Irradiation Facilities , Inspection of Radiation Sources and Regulatory Enforcement: Specific Safety Guide” by the International Atomic Energy Agency: “Conventional norms, codes or standards that address hazards due to external events may be used for assessing the potential hazards, and for designing facilities that can withstand such hazards, the radiation risks associated with the facility being taken into account.” And paragraph 8.32, “In seismic areas, all irradiation facilities should be equipped with instrumentation to warn of the occurrence of a seismic event and to disable the means of producing radiation. The seismic instrumentation should be firmly anchored to a concrete shield wall. The instrumentation may be of a horizontal, omni-axial type or a vertical, uni-axial type. It should be set to actuate at the lowest practicable level that will not generate false alarms.”
Our partner Radchem Co Ltd., of Hungary, provides consultancy services related to isotope production, applications and radiation technology. In accordance with the guidelines above, NPP Paks worked with Radchem to install two GMSplus 43i to monitor two Category II panoramic dry source storage irradiators.
Another Solution using GeoSIG instruments and a capable Partner effectively showing that quality and reliability can also be cost-effective.
Case Study:Structural Monitoring - Metsovo Bridge, Greece
Metsovo Bridge, Greece
Metsovo Bridge is a highway bridge in the course of the east-west connection “Egnatia Odos” in the north of Greece. The 4-span, totally 540 m long prestressed concrete bridge traverses an approximately 120 m deep ravine and lies between two tunnel portals. The main span is given with 235 m. The deck is constructed to the balanced cantilever method. Both main piers are founded on shafts with diameters of 12 m and length up to 25 m.
The bridge design is governed mainly by the high seismic loads in this region. It has been noted that Greece and the surrounding area is the most seismically active region of Europe. The scope of the project was monitoring the structure with respect to ground motions and other ambient dynamic activity such as dynamic loads imposed by traffic, environmental effects, etc.
With their impressive experience in this field, our Partner in Greece, Eurotech SA, was chosen to offer a bridge monitoring solution. For more than 25 years, Eurotech has provided large construction projects and industry in Greece with measuring instruments and specialised equipment, as well as consulting services.
The system for Metsovo Bridge is composed of two main sensor groups and the central acquisition computer. The first group measures the acceleration of the ground and vibrations of the bridge with four AC-63 triaxial force balance accelerometers, which are placed on the basement of two main pylons and in the maintenance tunnel below the deck.
The second group consists of 14 GSG-XX strain gauge sensors and four GSLVDT displacement transducers, as well as a meteorological sensor (METEOWDST) to measure wind speed and direction. The displacement transducers are located at the end of the bridge at the conjunction point between the bridge and the ground, whereas the strain gauge sensors are positioned in different points along the bridge (see figure).
All measured data are acquired at the Central Recording Unit (CR-5P), which integrates the digitiser board and an industrial PC in one platform, simply controlled through the Windows XP operating system. The measured data are managed by GeoSIG-developed seismic software GeoDAS.
Another Solution using GeoSIG instruments and a capable Partner effectively showing that quality and reliability can also be cost-effective.
Case Study:Structural Monitoring - Humber Bridge, England
Humber Bridge, England
When opened in 1981, the Humber Bridge in the UK was the largest single span bridge in the world with a total length of 2,220m. It spans the Humber estuary between Barton-upon-Humber on the south bank and Hessle on the north bank, connecting the East Riding of Yorkshire and North Lincolnshire. The road distance in the UK between Hull and Grimsby was reduced by nearly 80km as a result of this transportation achievement. Where the UK leads, the rest of the world eventually follows; in 1998 it was surpassed by Akashi Kaikyo Bridge in Japan, and today the Humber Bridge in the UK is further down the list of largest single span bridges.
Bridge monitoring has since moved into the 21st century with technology changes that have moved away from analogue to digital bridge monitoring solutions. Such new technologies bring with them the need re-evaluate the most suitable monitoring solutions, and in this instance re-evaluations were necessary on the modal properties of the Humber Bridge alongside the viability of using standalone recorders with provision timing (via GPS) to provide histories of response within the analysis of such an extended open space structure. The Humber Bridge as designed can tolerate constant motion and bends more than 3 m in winds of 129 km/hr (80 mph), at which point safety factors emerge; but the towers, although both vertical, are not parallel — these being under 50mm further apart at the top than at the bottom.
An international team comprising: Prof. JMW Brownjohn, University of Sheffield, UK; Dr. Paul Reynolds, University of Sheffield, UK; Mr. Chris Middleton, University of Sheffield, UK; Mr. Filipe Magalhaes, FEUP Porto, Portugal; Prof. Elsa Caetano, FEUP Porto, Portugal; Prof. Ivan Au, City University Hong Kong; and Prof. Paul Lam, City University Hong Kong; with support from Dr. Ivan Munoz Diaz; Prof. Aleksandar Pavic; Dr. Stana Zivanovic; Mrs. Eunice Lawton; Mrs. Tuan Norhayati Tuan Chik and Mr. Mohammad Muaz Aldimashki from Sheffield; Prof. Alvaro Cunha from FEUP; and Mr John Cooper, Mr Peter Hill and Mr Ian Allenby from Humber Bridge Board, tested the bridge during the week 14-18 July 2008 as part of an EPSRC-funded research project: EP/F035403/1, Novel Data Mining and Performance Diagnosis Systems for Structural Health Monitoring of Suspension Bridges. Monitoring done in 1985 was analogue, and the tapes were no longer readable.
The new study involved new instruments consisting of 10 GSR-24’s utilising internal or external accelerometers, all brought together from FEUP and Sheffield. The testing was divided into 28 measurements spanning five days. For example on day 2, measurements concentrated on the southern part of the bridge, in the direction of the town of Barton. Each of the box sections of the bridge, is identified by an odd number with prefix b (for Barton, south) or h (for Hessle, north). Recordings were made mainly at alternate hanger locations, in each case maintaining at least one fixed (reference) location on the main span. The set of seven measurements on day 2 used a reference pair (21h) on the Hessle side and one (49b) on the Barton side, with the remaining three pairs of recorders roving on the Barton side with 10 minutes to relocate between one-hour recordings. Measurements included one at the Barton tower (78b) including locations 77b/79b across the bearings, then moved into the Barton side span. Measurement setup 14a was a short recording to cross-check calibrations. The configuration for measurement setup 9 is shown in Figure 3. The red dots indicate the 10 recorder locations.
Case Study:Structural Monitoring - Øresund Bridge, Sweden - D
Øresund Bridge, Sweden - Denmark
The strait between Sweden and Denmark can be crossed by a combined railway and motorway bridge named Øresund Bridge, which runs nearly 8 km from the Swedish coast to an artificial island (Peberholm) in the middle of the strait. From there travelers take the Drogden Tunnel the 4 km from Peberholm to the Danish island of Amager. The Øresund Bridge connects Copenhagen, Denmark, and Malmö, Sweden; and it is noted for being the longest combined road and rail bridge in Europe.
Øresund is an impressive highway and railway link consisting of an immersed tunnel, artificial island and a combination bridge requiring observation of the oscillations of cables of the stayed bridge under heavy wind conditions. The scope of the Øresund project was to deliver a Cable Stayed Bridge Structural Monitoring System.
The bridge system solution monitors the deflections of the bridge under loads generated by highway and railway traffic. Excesses of any threshold values are recorded and managed from an on-site traffic control centre.
The system comprises 105 channels and a data acquisition and processing centre; and digital RS-485 cable communication with provision for 15 hours’ autonomy in case of power failure. Temperature/environmental data correlation are made alongside strain gauge measurements with 14 metereological sensors (METEO-TT & METEO-WSDT), 19 GSG-xx strain sensors and 22 AC-53 triaxial force balance accelerometers. A single CR-4 PC-based recording system is used for running programs, SEISLOG data acquisition, CENTRAL remote access, CMS, and static data processing. A telephone line connection to the traffic control centre is provided for data, event and alarm transmission.
Another great solution using GeoSIG instruments, showing that quality and reliability can also be cost-effective.
Case Study:Structural Monitoring - Preveza Tunnel, Greece
Preveza Tunnel, Greece
Throughout history, the strait that separates mainland Greece from Epirus in the Ambracian Gulf was crossed only by ferry boat with frequent problems due to rough seas, lack of night routes and long waiting hours during summer. In the mid-1990s, Greece sought to remedy this problem by constructing an immersed tunnel between Preveza and Aktio -- one of the nation’s most expensive public works. The tunnel was completed in 2002.
One aspect of the Preveza-Aktio immersed tunnel project was to provide a seismic tunnel monitoring system, where the tunnel equipment monitored the seismic effects of earth activity alongside the dynamic loads of natural transportation movements whether planned or by any unforeseen event. The scope included expansion or contraction surveillance due to the intensity of temperature changes impacting on the tunnel monitoring environment through whatever reason.
GeoSIG, through its Partner Eurotech SA, was able to provide four triaxial force balance accelerometers, 44 linear variable displacement transluder sensors, 2 meteorological sensors to measure humidity and temperature, and a data acquisition and processing center with GeoDAS software. The data is then assessed and compared to tunnel data recorded against seismic design criteria applicable to tunnel structural design and construction.
Improvements to tunnel emergency and safety measuring solutions as well as awareness also featured alongside the needs to appropriately maintain tunnel data management systems given the wider scope of measuring solutions possible within this segment owing to geographical location. A control center monitors the entire tunnel, hosting equipment responsible for the operation and monitoring of the project and various other systems responsible for the safe and proper use of the undersea tunnel.
What used to be a sometimes maddening undertaking to cross the strait has now become simplicity itself. Drivers using the undersea tunnel can cross the distance in 1 to 1.5 minutes driving a maximum speed of 60 km/h, and they are confident they can do so safely thanks to the measures undertaken by all participants in the project, including GeoSIG and its Partner Eurotech SA.
Another Solution using GeoSIG instruments and a capable Partner demonstrating that quality and reliabiilty can also be cost effective.