Gokhan Kilic

Applications of Ground-Penetrating Radar (GPR) to Detect Hidden Beam Positions

Ground-penetrating radar (GPR) uses electromagnetic waves to investigate the structures. In this investigation method, an electromagnetic wave is transmitted using an antenna and the received signal is recorded. Detection of beam positions in this GPR data requires the skills of a trained human operator. This study utilized a multi-layer neural network to detect beam positions in the GPR data. The visual description and definition of GPR data has major disadvantages and a neural network has been studied to overcome these shortcomings. A set of 32,740 training vectors with a length of 64 data was implemented to train the neural network. A new set of 16,370 testing vectors with a length of 64 data was then prepared to test the performance. Testing results suggest that the neural network is promising methods for the detection of beam positions in the GPR data.

GPR Raw-Data Order Statistic Filtering and Split-Spectrum Processing to Detect Moisture

Considerable research into the area of bridge health monitoring has been undertaken; however, information is still lacking on the effects of certain defects, such as moisture ingress, on the results of ground penetrating radar (GPR) surveying. In this paper, this issue will be addressed by examining the results of a GPR bridge survey, specifically the effect of moisture in the predicted position of the rebars. It was found that moisture ingress alters the radargram to indicate distortion or skewing of the steel reinforcements, when in fact destructive testing was able to confirm that no such distortion or skewing had occurred. Additionally, split-spectrum processing with order statistic filters was utilized to detect moisture ingress from the GPR raw data.

Performance evaluation of the neural networks for moisture detection using GPR

Ground penetrating radar (GPR) is a highly researched area; however, despite this, there is a lack of knowledge about the well-known problem of moisture distorting the results of GPR surveys. This research analyses the results of a GPR survey on a Case Study Bridge structure in order to analyse this effect, specifically when checking for the positioning of rebar. The expected distortions of the GPR results due to the presence of moisture were indeed present, as further evidenced by subsequent destructive testing and velocity analysis. Furthermore, neural networks were also utilised to detect moisture ingress from the GPR raw data.

GPR Raw-Data Analysis to Detect Crack Using Order Statistic Filtering

Ground penetrating radar (GPR) uses data collected with the aid of electromagnetic waves transmitted into a structure by antenna to assess and monitor the structural health of many different kinds of civil infrastructure. With GPR technology promoting their system with promises of the achievement of in excess of 1000 sample points per scan, this research demonstrated on the basis of the Nyquist theorem that 256 sample points per scan provided equally reliable inspection results. Furthermore, 256 sample points per scan GPR data were further analyzed by order statistic filtering with neural networks to locate cracks within concrete materials. The results showed that the neural network order statistic filters are effective in their use of detecting cracks in noisy environments using 256 sample points per scan GPR data.

Corroboration of NDT and deconvolution neural networks for pedestrian bridge health assessment

This paper describes the specific application of the non-destructive testing methods of visual inspection and ground penetrating radar (GPR) to a pedestrian bridge in Izmir, Turkey. The paper concentrates on the implementation of a deconvolution neural network (DNN) which is a procedure that employs neural network algorithms. By introducing collected GPR data to the DNN, the existence and location of cracks, rebar and moisture ingress on pedestrian pathways can reliably be located, thus providing superior information on which decisions relating to the functionality and life expectancy of a structure can be formulated. This study will be of benefit to engineers in providing a detailed and dependable assessment of the current state of structures such as pedestrian bridges.

Building Conservation Towards a Sustainable Future: Use of GPR

According to the website of Mary Robinson Foundation for Climate Justice, 2.7 Million people worldwide, most of them being extremely poor and 1.3 billion of them with no access to electricity, rely on solid fuels such as traditional biomass and coal for cooking and heating. In this world where a number of experts are concentrating their research on finding alternative and environmentally friendly energy sources, masses of existing buildings are being demolished causing energy loss and polluting the environment with demolition waste. These demolitions are justified through the conventional scientific belief introduced by modernity that older buildings are of poor quality.

A New Approach for Determination of Adhesion Coefficient in Pipejacking Method by Experimental and Numerical Analysis: An Example from Istanbul

The common technique used for the construction and maintenance of infrastructure facilities until recently involved traditional open excavation methods. Technological advancements and developments in gathering geotechnical information on our working environment have given birth to the development of new methods which will prevent problems that may have emerged due to the use of traditional methods during the construction of infrastructure facilities. One of these new methods is trenchless technology which is becoming increasingly popular in the infrastructure construction industry. One of its processes, the pipejaking process, is of special importance in busy urban centres and densely populated living quarters as it has proved to be the most sustainable method for working in such environments and for global use. The name of this process is trenchless technology. There is an increasing demand for infrastructure systems, especially in cities, because of increasing populations and varying lifestyles, and in the areas around cities which are environmentally sensitive. Routes of infrastructure (pipelines) to be constructed have many obstructions such as motorways, buildings, railways, rivers, creeks, and canals. The pipejacking process, a trenchless technology to overcome these problems and obstructions, has been achieving an important scope of application in Turkey and the rest of the world. Infrastructure facilities planned to be constructed by the application of this system can be built under every kind of ground condition in a correct, swift, and economic manner, without needing an open excavation and its associated traffic problems and conditions that may cause danger to human life and property. Within the context of this study, the collector line, constructed in Şile district by the pipejacking process (which is 1535 m in length and 800 mm in diameter), was examined, and jacking force length graphics were prepared with the use of jacking force records obtained from the machine. After analysing these graphics, change of coefficients of α adhesion was researched and, for use at cohesioned grounds, an α value was suggested in order to predict friction resistance and accordingly possible jacking force values that may be faced. First, with the assistance of the Plaxis 3D Tunnel Program, considering land conditions, the examined line was modelled. Then, stress values resulting from this modelling and graphic analyses were compared, and observed harmonies or inharmonies were discussed. Lastly, parameters that are effective on these harmonies or inharmonies were defined. In addition, considering jacking forces and stress values observed where bentonite is whether used or not, the lubricant’s effect on the jacking action was examined. Within the context of this study, stoppages, lubrication during jacking process, and their effects on the jacking force and stresses were analysed. Thus, a versatile study regarding the pipejacking process has been put forward for consideration.