Berthelot C.,University of Saskatchewan |
Podborochynski D.,University of Saskatchewan |
Saarenketo T.,Roadscanners Oy |
Marjerison B.,Preservation and Surfacing Saskatchewan |
Prang C.,Infrastructure Preservation City of Saskatoon
Advances in Civil Engineering | Year: 2010
This study was undertaken to evaluate the effect of soil type, moisture content, and the presence of frost on road substructure permittivity. Permittivity sensitivity of typical road soils was characterized in the laboratory to provide baseline dielectric constant values which were compared to field ground penetrating radar (GPR) survey results. Both laboratory devices, the complex dielectric network analyzer and the Adek Percometer, as well as the field GPR system were used in this study to measure the dielectric constant of soils. All three systems differentiated between coarse-grained and fine grained soils. In addition, at temperatures below freezing, all three systems identified an increase in water content in soils; however, when frozen, the sensitivity of dielectric constant across soil type and moisture content was significantly reduced. Based on the findings of this study, GPR technology has the ability to characterize in situ substructure soil type and moisture content of typical Saskatchewan road substructure soils. Given the influence of road soil type and moisture content on in-service road performance, this ability could provide road engineers with accurate estimates of in situ structural condition of road structures for preservation and rehabilitation planning and optimization purposes. Copyright 2010 Curtis Berthelot et al.
Agency: European Commission | Branch: H2020 | Program: MSCA-RISE | Phase: MSCA-RISE-2015 | Award Amount: 1.17M | Year: 2016
Social and economic growth, security and sustainability in Europe are at risk of being compromised due to aging and failing railway infrastructure systems. This partly reflects a recognised skill shortage in railway infrastructure engineering. This project, RISEN, aims to enhance knowledge creation and transfer using both international and intersectoral secondment mechanisms among European Advanced Rail Research Universities/SMEs and Non-EU, world-class rail universities including the University of Illinois at Urbana Champaign (USA), Massachusetts Institute of Technology (USA), Southwest Jiaotong University (China) and University of Wollongong (Australia). This project adds research skill mobility and innovation dimension to existing bilateral collaborations between universities through research exchange, joint research supervision, summer courses, international training and workshops, and joint development of innovative inventions. It spans over 4 years from April 2016 to March 2020. RISEN aims to produce the next generation of engineers and scientists needed to meet the challenge of providing sustainable, smart and resilient railway infrastructure systems critical for maintaining European competitiveness. The emphasis will be placed on the resilience and adaptation of railway and urban transport infrastructures using integrated smart systems. Such critical areas of the research theme will thus be synergised to improve response and resilience of rail infrastructure systems to climate change, extreme events from natural and human-made hazards, and future operational demands. In addition, researchers will benefit from the co-location of engineering education, training and research alongside world-class scientists and industry users through this initiative. Lessons learnt from rail infrastructure management will be shared and utilised to assure integrated and sustainable rail transport planning for future cities and communities.
Kantia P.,Geofcon |
Heikkinen E.,Pöyry |
Mustonen S.,Posiva Oy |
Mellanen S.,Genpro Solutions |
And 2 more authors.
Underground - The Way to the Future: Proceedings of the World Tunnel Congress, WTC 2013 | Year: 2013
Preparations for geological disposal of spent nuclear fuel are in progress by Posiva Oy and SKB, who have developed a KBS-3 method for the purpose. Deposition tunnels are excavated using drill and blast method. On tunnel floor, approx. 1.7 (Ø) x 8.7 (h) m wells are bored to accommodate fuel canisters surrounded with bentonite buffer. Excavation will induce a damaged zone (EDZ) in tunnel perimeter and that is considered a major risk for long term safety of disposal as EDZ may constitute a continuous ground water flow path for radio nuclides. Use of Ground Penetrating Radar as a non-destructive method for characterization of EDZ was introduced by Posiva. A 1.5 GHz antenna was addressed into contact with clean, dry rock surfaces to detect changes of electrical resistivity in relation with variation of rock porosity. Electrical resistivity is highly dispersive at high frequencies. This enables use of dispersivity as a measure of EDZ. Computed dispersivity index gives data for EDZ visualization. Task required software development and establishing threshold values of dispersion. Method was verified with sample studies. Measurement is quick and easy to apply. Computed results are standardized. The method confirms relation between extent of fracturing and charge rate and turned out quick, reliable tool for excavation quality control. Method may apply also for tunnel safety monitoring. © 2013 Taylor & Francis Group.
Kantia P.,Posiva Oy |
Heikkinen E.J.,Pöyry |
Lehtimaki T.,Swedish Nuclear Fuel and Waste Management Company |
Silvast M.,Roadscanners Oy
Near Surface Geoscience 2012 | Year: 2012
Posiva and SKB are preparing for disposal of spent nuclear fuel deep in the crystalline bedrock. Fuel assemblies are planned to be encapsulated in copper canisters and placed in wells into tunnel floor. Disposal tunnels will be constructed using Drill and Blast method which unavoidably causes EDZ, being one concern in terms of long term safety as it may constitute a hydraulic flow path. As a non destructive and effective method the GPR technique was introduced for EDZ characterization. The GPR EDZ method was tested in several field campaigns in Äspö and in Olkiluoto. High frequency GPR antenna was used in the work on lines parallel to the tunnel. On high frequencies the resistivity is highly dispersive. Detection of the EDZ is based on computing of dispersivity index in a moving window. The EDZ data can be displayed as profiles, maps or volume visualisation. The developed GPR EDZ technique proved to be a quick and effective in locating areas suffering EDZ. The EDZ was indicated to be discontinuous in character. The next stage of method development will use rock sample data and other geophysical methods in verification. Hydraulic conductivity of EDZ volume is also necessary to define.
Silvast M.,Roadscanners Oy |
Nurmikolu A.,Tampere University of Technology |
Wiljanen B.,Roadscanners Oy |
Levomaki M.,Finnish Transport Agency
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2013
In Finland, the railway is a vital transportation system. A large quantity of raw materials, goods and passengers are transported on mixed traffic tracks. Due to freeze-thaw cycles, differential frost heave can affect the track performance and results in speed restrictions. The maintenance of winter-related problems on heavy haul railway lines is expensive and causes difficulties for the flow of rail traffic. In order to make maintenance cost-effective and sustainable it is essential to identify the problem areas and determine their causes. During the last decade the ground penetrating radar (GPR) technique has proven to be an effective and non-destructive method to measure railway structures and various material properties. This paper presents and discusses the key results obtained in a research project that studied the potential of the GPR method to locate track sections on Finnish railways experiencing frost problems and produce input data for preventative maintenance planning for areas at risk of developing differential frost heave. The GPR data, digital video and GPS coordinates, collected from the railway sections were combined with reference data and railway databases using the Railway Doctor software. This integrated data was then interpreted and analysed using multiple parameters specifically selected for the purpose of identifying the frost-susceptible sub-ballast structures and subgrade soils and defining the root cause of frost problems using the GPR frequency analysis techniques.This paper originated from the 2011 IHHA Conference. © IMechE 2012.
Silvast M.,Roadscanners Oy |
Nurmikolu A.,Tampere University of Technology |
Wiljanen B.,Roadscanners Oy |
Levomaki M.,Finnish Rail Administration
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2010
The maintenance of heavy haul railway lines causes considerable cost and in many cases difficulties to rail traffic. Railway infrastructure management in Finland is important because in many locations the same railway lines are used by both freight and passenger trains. Along with the mixed traffic, the cold climate presents challenges in keeping the track in good condition. There is a great demand for economical and non-destructive methods that provide continuous condition information of track structure. In recent years, the ground penetrating radar (GPR) technology for structure inspection has improved to faster systems and better data quality. This article presents the main results from a research programme that was aimed to identify different GPR-based railway ballast degradation classes and to develop a preventative maintenance planning system. An extensive reference sampling and laboratory analysis has been performed to aid in developing the GPR-based classification method for qualifying the ballast fouling. Classification is made by a fouling index, which is calculated from the frequency contents of the GPR signal. This quality classification can be utilized in the planning of undercutting programmes.
Hamrouche R.,Roadscanners Oy |
Saarenketo T.,Roadscanners Oy
Proceedings of the 15th International Conference on Ground Penetrating Radar, GPR 2014 | Year: 2014
The need for more effective road condition management policies and practices has been growing rapidly over the last few years. A key word in this development is 'focus' and for that more accurate and reliable continuous NDT survey methods, such as GPR, are needed. In asphalt thickness surveys a problem has been how to calculate/estimate the dielectric value of the asphalt. Thus far this has been done using drill cores or using the surface reflection technique. Within this context, this study is aimed at defining an accurate coreless method to calculate the average dielectric value of the whole asphalt layer of a road pavement using GPR (horn antennas). To accomplish this, the WARR (Wide Angle Reflection and Refraction) technique is applied. The principle is based on the resolution of a system of two nonlinear equations with two unknowns (asphalt thickness and electromagnetic wave velocity) using reflection the different time shift. An initial validation under controlled conditions was conducted and then followed by a series of measurements on a dedicated test field in order to validate and check the accuracy of the results given by our calculations. The results obtained are promising and a series of tests on real roads are under preparation. © 2014 IEEE.
Roadscanners Oy | Date: 2011-05-26
In the method an existing surface of a bearing course (120) of a traffic route is first chosen as the reference level (100), in relation to which the target level (150) of a surface of a bearing course to be formed is determined. After this the forming procedure of a bearing course is performed, in which the surface of a bearing course is brought to the target level. Typically the forming procedure comprises spreading, levelling and compacting of a soil layer on the surface of the reference level. The location of a traffic route is determined in the terrain as plane coordinate points (x_(n), y_(n)) with a satellite positioning method and the elevation z_(n )of an existing bearing course chosen as the reference level is determined in each coordinate point (x_(n), y_(n)) as cross sectional figures extending from the unchanged terrain on the first side of the traffic route over the surface of the traffic route to the unchanged terrain on the second side of the traffic route. The cross sectional figures are determined with laser scanning. The laser scanning can be performed form a vehicle (300) or a construction machine travelling along the traffic route.
Roadscanners Oy | Date: 2011-06-01
The method is meant for the evaluating of the amount of micro and macro cracks in the pavement of a traffic lane, such as a road or street. The colder water beneath the pavement is under the load of heavy traffic pumped into the micro and macro cracks in the pavement and lowers the temperature of the pavement, so a large difference between the temperatures in different points on the pavement reveals a large amount of cracks. In the method, the examination span of the traffic lane is first selected. Thereafter the temperature T1 of the heavily loaded part of the pavement of the selected examination span and the temperature T2 of the lightly loaded part of the pavement of the same examination span are determined. A difference AT between the determined temperatures is calculated, which difference is compared to a reference value. If the difference is larger than the used reference value, the pavement lets through a significant amount of water. If the difference is smaller than the used reference value, the condition of the pavement is sufficiently good. The temperatures t of the heavily loaded part of the pavement are measured at the wheel ruts and the temperatures t of the lightly loaded part of the pavement are measured in the area outside the wheel ruts. The temperatures of the pavement are measured with an apparatus, which is placed in a vehicle travelling on the traffic lane. Alternatively the emissivity of the heavily loaded part of the pavement and the emissivity of the lightly loaded part of the pavement can be determined and the difference can be compared to a reference value.
Roadscanners Oy | Date: 2011-11-30
In the method some existing surface of a bearing course (120) of a traffic route is first chosen as the reference level (100), in relation to which the target level (150) of a surface of a bearing course to be formed is determined. For example the upper surface of a surface layer of a traffic route can be chosen as the reference level. After this the forming procedure of a bearing course is performed, in which the surface of a bearing course is brought to the target level. Typically the forming procedure of a bearing course comprises spreading, levelling and compacting of a soil layer on the surface of the reference level. The location of a traffic route is determined in the terrain as plane coordinate points (x_(n), y_(n)) and the elevation z_(n) of an existing bearing course chosen as the reference level is determined in each coordinate point (x_(n), y_(n)) as cross sectional figures extending from the unchanged terrain on the first side of the traffic route over the surface of the traffic route to the unchanged terrain on the second side of the traffic route. The coordinate points (x_(n), y_(n)) of the location are determined with a satellite positioning method. The measurement data is saved as spatial coordinate points (x_(n), y_(n), z_(nr)) into a given value data file (242), which is used in the later stages of the forming of the bearing course. The elevations z_(nm) of the level of the upper surface of the bearing course formed and the elevations z_(nr) of the reference level are determined in the coordinate point (x_(n), y_(n)) of the traffic route with laser scanning. The laser scanning can be performed form a vehicle (300) travelling along the traffic route and/or a construction machine participating in the forming of the bearing course, travelling along the traffic route.