Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120021
D. Souriou, A. Ihamouten, S. Kadkhodazadeh, B. Fan, D. Guilbert
Summary In this paper, we propose to show the results of an experimental study to validate a concept of a new Structure Health Monitoring (SHM) sensor dedicated to the detection of aggressive agents in reinforced concrete structures. This sensor, aimed to be embedded in cover concrete, is composed with a permanent part, that acts as a reference magnetic source, coupled with a magneto-functional material (or reactive part), directly in touch with aggressive agents (chlorides in our case) that can cause its corrosion. As a function of its corrosion rate, the reactive part can filter differently a magnetic non destructive observable measured from the permanent part. We chose to present measurements of the magnetic non destructive observable of sensors with reactive parts in their initial and corroded states. The influence of reactive part’s thickness and corrosion rate (based on relative mass loss of reactive part) are shown. Variations of the magnetic observable can be correlated with mass loss of reactive part. These results allowed to draw a empirical calibration curves providing a possibility to monitor reactive part’s corrosion rate. These informations could be used to detect the presence of aggressive agents before they reach rebars.
{"title":"Experimental Study to Characterize a Magneto-Functional Technology vs. Corrosion in Reinforced Concrete Structures","authors":"D. Souriou, A. Ihamouten, S. Kadkhodazadeh, B. Fan, D. Guilbert","doi":"10.3997/2214-4609.202120021","DOIUrl":"https://doi.org/10.3997/2214-4609.202120021","url":null,"abstract":"Summary In this paper, we propose to show the results of an experimental study to validate a concept of a new Structure Health Monitoring (SHM) sensor dedicated to the detection of aggressive agents in reinforced concrete structures. This sensor, aimed to be embedded in cover concrete, is composed with a permanent part, that acts as a reference magnetic source, coupled with a magneto-functional material (or reactive part), directly in touch with aggressive agents (chlorides in our case) that can cause its corrosion. As a function of its corrosion rate, the reactive part can filter differently a magnetic non destructive observable measured from the permanent part. We chose to present measurements of the magnetic non destructive observable of sensors with reactive parts in their initial and corroded states. The influence of reactive part’s thickness and corrosion rate (based on relative mass loss of reactive part) are shown. Variations of the magnetic observable can be correlated with mass loss of reactive part. These results allowed to draw a empirical calibration curves providing a possibility to monitor reactive part’s corrosion rate. These informations could be used to detect the presence of aggressive agents before they reach rebars.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129056756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120086
A. Verweerd, J. Gomery
Summary Case study investigation failure mechanism of a road in Derbyshire (UK). The road is located on a ridge, with steep slopes on either side as well as known historical mineworkings in close vicinity. A multi-disciplinary geophysical survey was executed to identify the potential failure mechanism after cracks in the road surface were observed. The combined interpretation of all techniques provided a detailed image of the subsurface allowing identification of the most likely failure mechanism, which will be used in design of a remediation strategy.
{"title":"Multi-disciplinary geophysical investigation to identify road failure mechanism","authors":"A. Verweerd, J. Gomery","doi":"10.3997/2214-4609.202120086","DOIUrl":"https://doi.org/10.3997/2214-4609.202120086","url":null,"abstract":"Summary Case study investigation failure mechanism of a road in Derbyshire (UK). The road is located on a ridge, with steep slopes on either side as well as known historical mineworkings in close vicinity. A multi-disciplinary geophysical survey was executed to identify the potential failure mechanism after cracks in the road surface were observed. The combined interpretation of all techniques provided a detailed image of the subsurface allowing identification of the most likely failure mechanism, which will be used in design of a remediation strategy.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127786511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120033
M. Hickey, S. Treviño, M. Everett
Summary Maintenance of buried steel infrastructure is an important problem in civil engineering practice. Corrosion, for example, can lead to damage and excessive repair or replacement expenses. Soil corrosivity is one of the main physical factors that determines the corrosion rate of pipelines and other steel infrastructure. Methods that can reliably estimate soil corrosivity by non-invasive and inexpensive means would be of great benefit to the civil engineering community. Soil corrosivity is well-known to depend on multiple interacting physical factors such as moisture content, aeration, pH, organic matter content, microbial activity, etc. However, in most cases a dry and/or sand-dominated soil is electrically resistive and generally less corrosive in comparison with a wet and/or clay-dominated soil characterized by lower bulk resistivity. In this paper, with the objective of evaluating terrestrial CSEM as a potential tool for mapping possible corrosion of buried steel infrastructure, we examine synthetic responses from a terrestrial CSEM layout and report the magnitudes and characteristics of secondary signals that are caused by the presence of a zone of anomalous soil resistivity surrounding a uniform steel pipe. Further consideration of development of a practical slingram-type terrestrial CSEM system for steel infrastructure investigation is recommended.
{"title":"Terrestrial CSEM for buried steel infrastructure","authors":"M. Hickey, S. Treviño, M. Everett","doi":"10.3997/2214-4609.202120033","DOIUrl":"https://doi.org/10.3997/2214-4609.202120033","url":null,"abstract":"Summary Maintenance of buried steel infrastructure is an important problem in civil engineering practice. Corrosion, for example, can lead to damage and excessive repair or replacement expenses. Soil corrosivity is one of the main physical factors that determines the corrosion rate of pipelines and other steel infrastructure. Methods that can reliably estimate soil corrosivity by non-invasive and inexpensive means would be of great benefit to the civil engineering community. Soil corrosivity is well-known to depend on multiple interacting physical factors such as moisture content, aeration, pH, organic matter content, microbial activity, etc. However, in most cases a dry and/or sand-dominated soil is electrically resistive and generally less corrosive in comparison with a wet and/or clay-dominated soil characterized by lower bulk resistivity. In this paper, with the objective of evaluating terrestrial CSEM as a potential tool for mapping possible corrosion of buried steel infrastructure, we examine synthetic responses from a terrestrial CSEM layout and report the magnitudes and characteristics of secondary signals that are caused by the presence of a zone of anomalous soil resistivity surrounding a uniform steel pipe. Further consideration of development of a practical slingram-type terrestrial CSEM system for steel infrastructure investigation is recommended.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116735014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120031
A. Sendrós, M. Himi, C. Abancó, R. Lovera, L. Rivero, A. Urruela, R. García‐Artigas, A. Casas
Summary The occurrence of large landslides in the slopes of reservoirs may produce a reduction of the water storage capacity and generate water waves which could cause catastrophic flooding if the dam crest is overtopped or breached. The massive and catastrophic rockslide of Vajont reservoir that occurred in 1963 demonstrated the importance of performing detailed geological, geomorphological, hydrogeological and geotechnical investigations in rock masses and soil slopes. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological changes that has demonstrated useful to provide the detailed subsurface information required to improve the diagnosis of the slope stability and finding the most suitable zones to fail. The relationships between the electrical resistivity of the high and low-bearing capacity sediments identified in Canelles site highlight the potential of geoelectical methods over other more costly subsurface exploration techniques. The proposed approach show potential to be applied coupled to numerical models to define the boundary conditions up to 100 meters depth with a 5–10 meters resolution and could also help to optimize the required borehole research and monitoring campaign in the initial research stages of landslide characterization.
{"title":"Electrical imaging of the slip geometry of a deep-seated landslide (Canelles Dam, NE Spain)","authors":"A. Sendrós, M. Himi, C. Abancó, R. Lovera, L. Rivero, A. Urruela, R. García‐Artigas, A. Casas","doi":"10.3997/2214-4609.202120031","DOIUrl":"https://doi.org/10.3997/2214-4609.202120031","url":null,"abstract":"Summary The occurrence of large landslides in the slopes of reservoirs may produce a reduction of the water storage capacity and generate water waves which could cause catastrophic flooding if the dam crest is overtopped or breached. The massive and catastrophic rockslide of Vajont reservoir that occurred in 1963 demonstrated the importance of performing detailed geological, geomorphological, hydrogeological and geotechnical investigations in rock masses and soil slopes. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological changes that has demonstrated useful to provide the detailed subsurface information required to improve the diagnosis of the slope stability and finding the most suitable zones to fail. The relationships between the electrical resistivity of the high and low-bearing capacity sediments identified in Canelles site highlight the potential of geoelectical methods over other more costly subsurface exploration techniques. The proposed approach show potential to be applied coupled to numerical models to define the boundary conditions up to 100 meters depth with a 5–10 meters resolution and could also help to optimize the required borehole research and monitoring campaign in the initial research stages of landslide characterization.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124034483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120070
R. Jaufer, A. Ihamouten, Shreedhar Savant Todkar, F. Bosc, Y. Goyat, X. Dérobert
Summary Ground Penetrating Radar (GPR) has become one of the popular Non-Destructive Testing (NDT) methods in the field of Geophysics and civil engineering applications. In this context, for applications like concrete rebars assessments, utility networks surveys, the precise localization of embedded cylindrical pipes remains still challenging due to complex geometrical and dielectric characteristics of the stratified medium. In recent years, several hyperbola-centric machines learning based novel techniques have been introduced to accomplish localization of cylindrical objects from the GPR data. In this paper, performance of Multi-layer perceptron (MLP) based Artificial Neural Networks (ANN) model combined with six statistical travel time features extracted from hyperbola were studied. The model is used to predict the velocity of the stratified medium, depth of cylindrical pipe and radius of the pipe. The approach is based on hyperbola traces emerging from a set of B-scans, whereas the shape of hyperbola highly varies with depth and radius of the pipe as well as the velocity of the medium. Hence, Finite-Difference Time-Domain (FDTD) based 2D numerical tool namely GprMax is used to simulate GPR data. A parametric comparison is also included in the performance analysis of the techniques in terms of relative error estimations against designed parameters.
{"title":"Use of Deep Lerning on GPR data for parameter inversion of buried cylindrical pipes","authors":"R. Jaufer, A. Ihamouten, Shreedhar Savant Todkar, F. Bosc, Y. Goyat, X. Dérobert","doi":"10.3997/2214-4609.202120070","DOIUrl":"https://doi.org/10.3997/2214-4609.202120070","url":null,"abstract":"Summary Ground Penetrating Radar (GPR) has become one of the popular Non-Destructive Testing (NDT) methods in the field of Geophysics and civil engineering applications. In this context, for applications like concrete rebars assessments, utility networks surveys, the precise localization of embedded cylindrical pipes remains still challenging due to complex geometrical and dielectric characteristics of the stratified medium. In recent years, several hyperbola-centric machines learning based novel techniques have been introduced to accomplish localization of cylindrical objects from the GPR data. In this paper, performance of Multi-layer perceptron (MLP) based Artificial Neural Networks (ANN) model combined with six statistical travel time features extracted from hyperbola were studied. The model is used to predict the velocity of the stratified medium, depth of cylindrical pipe and radius of the pipe. The approach is based on hyperbola traces emerging from a set of B-scans, whereas the shape of hyperbola highly varies with depth and radius of the pipe as well as the velocity of the medium. Hence, Finite-Difference Time-Domain (FDTD) based 2D numerical tool namely GprMax is used to simulate GPR data. A parametric comparison is also included in the performance analysis of the techniques in terms of relative error estimations against designed parameters.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133486486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120253
F. Rahimzadeh, A. Rodgers, A. Faramarzi, N. Metje, M. Stringfellow
Summary The Gravity survey and GPR have been widely used geophysical techniques. However, each suffer from inherent limitations. One approach for improvement of geophysical survey is to develop algorithms that incorporate data from multiple sensory systems. To this effect, this research employed GPR data as constraints for microgravity inversion technique. A GA-based gravity inversion was developed where the interpreted GPR data was imposed on the inversion. The results of a filed trial survey over a buried utility tunnel demonstrated improvement in identifying a utility tunnel by the proposed GPR-constrained microgravity inversion.
{"title":"Constraining gravity inversion using interpreted GPR data","authors":"F. Rahimzadeh, A. Rodgers, A. Faramarzi, N. Metje, M. Stringfellow","doi":"10.3997/2214-4609.202120253","DOIUrl":"https://doi.org/10.3997/2214-4609.202120253","url":null,"abstract":"Summary The Gravity survey and GPR have been widely used geophysical techniques. However, each suffer from inherent limitations. One approach for improvement of geophysical survey is to develop algorithms that incorporate data from multiple sensory systems. To this effect, this research employed GPR data as constraints for microgravity inversion technique. A GA-based gravity inversion was developed where the interpreted GPR data was imposed on the inversion. The results of a filed trial survey over a buried utility tunnel demonstrated improvement in identifying a utility tunnel by the proposed GPR-constrained microgravity inversion.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123976902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120250
P. Somerville
Summary The strength of earthquake ground motions for use in seismic design and evaluation depends strongly on the shallow subsurface shear wave velocity profile. Noninvasive geophysical exploration methods for estimating the subsurface shear wave velocity profile, including SASW, MASW and ReMi, are much more efficient than borehole methods, especially for application to extended foundations, and their routine application for dam and embankment foundation evaluation is becoming commonplace. Single station methods such as H/V and HVSR based on the ratio of horizontal to vertical ground motions are also available, and a new method using the P to S wave conversion at the bedrock interface is described.
{"title":"Measuring shallow shear wave velocity profiles for earthquake ground motion estimation","authors":"P. Somerville","doi":"10.3997/2214-4609.202120250","DOIUrl":"https://doi.org/10.3997/2214-4609.202120250","url":null,"abstract":"Summary The strength of earthquake ground motions for use in seismic design and evaluation depends strongly on the shallow subsurface shear wave velocity profile. Noninvasive geophysical exploration methods for estimating the subsurface shear wave velocity profile, including SASW, MASW and ReMi, are much more efficient than borehole methods, especially for application to extended foundations, and their routine application for dam and embankment foundation evaluation is becoming commonplace. Single station methods such as H/V and HVSR based on the ratio of horizontal to vertical ground motions are also available, and a new method using the P to S wave conversion at the bedrock interface is described.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"45 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114120938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120060
V. Gauthier, P. Labourg, J. Leonard, J. Rainaud
Summary The aim of this presentation in four parts is to present how the RESQML format previously designed to exchange between Geosciences applications can be used in the Geotechnical domain by a BIM (Building Information Modeling) software to receive a global consistent image of the subsoil combining Geology, Geotechnics and DTM (Digital Terrain Modeling). We present the main RESQML principles, explain how the RESQML format (www.energistics.org) handle semantically the subsurface information, and demonstrate how EGIS GROUP, an Environmental and Infrastructure Company, was setting up a software environment with the help of a Geoscience expert to communicate subsoil information to a BIM oriented software (CIVIL 3D from Autodesk). Then, we show on several Use cases how the information is finally integrated in a BIM environment to be used by operational teams. These use cases were realized by RESQML CAD, A plug-in for Autodesk Civil 3D, developed in C#.NET under Visual Studio in collaboration between EGIS and GEOSIRIS. This tool is providing Geotechnical information as horizons and faults of the 3D models, drawing boreholes in 3D, drawing fence-diagrams and 3D logs data to this BIM software. Each drawn element is also associated to a list of attributes in a BIM database
{"title":"Operational Use Cases Using Resqml Standard to Communicate Geotechnics and Subsurface Information to Bim","authors":"V. Gauthier, P. Labourg, J. Leonard, J. Rainaud","doi":"10.3997/2214-4609.202120060","DOIUrl":"https://doi.org/10.3997/2214-4609.202120060","url":null,"abstract":"Summary The aim of this presentation in four parts is to present how the RESQML format previously designed to exchange between Geosciences applications can be used in the Geotechnical domain by a BIM (Building Information Modeling) software to receive a global consistent image of the subsoil combining Geology, Geotechnics and DTM (Digital Terrain Modeling). We present the main RESQML principles, explain how the RESQML format (www.energistics.org) handle semantically the subsurface information, and demonstrate how EGIS GROUP, an Environmental and Infrastructure Company, was setting up a software environment with the help of a Geoscience expert to communicate subsoil information to a BIM oriented software (CIVIL 3D from Autodesk). Then, we show on several Use cases how the information is finally integrated in a BIM environment to be used by operational teams. These use cases were realized by RESQML CAD, A plug-in for Autodesk Civil 3D, developed in C#.NET under Visual Studio in collaboration between EGIS and GEOSIRIS. This tool is providing Geotechnical information as horizons and faults of the 3D models, drawing boreholes in 3D, drawing fence-diagrams and 3D logs data to this BIM software. Each drawn element is also associated to a list of attributes in a BIM database","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129679329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120005
C. Fabozzi, S. Vitale, C. De Paola, S. Ciarcia, R. Di Maio
Summary We present a geophysical study for the executive project of a railway tunnel across the Maddaloni-Durazzano carbonate ridge (southern Italy). To reconstruct the geological setting of the area, a N-S oriented electrical resistivity tomography (ERT) profile, about 4 km long, was performed, which allowed an exploration depth of about 200 m from the surface level. The results of the 2D inversion model of the ERT profile clearly highlight anomalous resistive blocks that can be associated with fractured/karst sectors of the Cretaceous carbonate succession affected by significant water circulation, while there are no evident resistivity anomaly features linked to the presence of large cavities. Significantly, the geophysical model identifies at the northern end of the ERT profile, where the entrance to the tunnel was planned, the presence of the regional thrust fault bounding the northern side of the ridge, which was hypothesized by the geological cartography but not supported by field observations. The validation of the geological-structural model provided by the ERT interpretation was derived from geognostic boreholes and direct observations carried out during the excavation of a tunnel crosscutting the ERT section.
{"title":"Geological Reconstruction by 2D-ERT of the Maddaloni-Durazzano Ridge (Italy) for a Railway Line Design","authors":"C. Fabozzi, S. Vitale, C. De Paola, S. Ciarcia, R. Di Maio","doi":"10.3997/2214-4609.202120005","DOIUrl":"https://doi.org/10.3997/2214-4609.202120005","url":null,"abstract":"Summary We present a geophysical study for the executive project of a railway tunnel across the Maddaloni-Durazzano carbonate ridge (southern Italy). To reconstruct the geological setting of the area, a N-S oriented electrical resistivity tomography (ERT) profile, about 4 km long, was performed, which allowed an exploration depth of about 200 m from the surface level. The results of the 2D inversion model of the ERT profile clearly highlight anomalous resistive blocks that can be associated with fractured/karst sectors of the Cretaceous carbonate succession affected by significant water circulation, while there are no evident resistivity anomaly features linked to the presence of large cavities. Significantly, the geophysical model identifies at the northern end of the ERT profile, where the entrance to the tunnel was planned, the presence of the regional thrust fault bounding the northern side of the ridge, which was hypothesized by the geological cartography but not supported by field observations. The validation of the geological-structural model provided by the ERT interpretation was derived from geognostic boreholes and direct observations carried out during the excavation of a tunnel crosscutting the ERT section.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130975109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.3997/2214-4609.202120124
G. Papadopoulos, ILIAS FIKOS, A. García-Jerez, N. Theodoulidis, G. Vargemezis
Summary The present work deals with the inversion of HVSR. curves to obtain shear wave velocity profiles and how a priori information could be incorporated to facilitate the H/V inversion procedure. The inversion is conducted using the “HV-Inv” computer code (Garcia-Jerez et al., 2016), which is based on the Diffuse Field Assumption and uses the relation between the HVSR and the elastodynamic Green’s function. This code is packed with 3 global (Monte Carlo sampling, Simulated Annealing and Modified Simulated Annealing) and 2 local (Simplex Downhill, Interior Point) inversion methods. Three test groups with different properties and with all 5 inversions methods are examined to test various capabilities of the software. A final test is conducted using the experience of the previous ones, achieving inversions with lower misfit.
本文研究的是HVSR的反演问题。以及如何将先验信息整合到H/V反演过程中。使用“HV-Inv”计算机代码(Garcia-Jerez et al.， 2016)进行反演，该代码基于漫射场假设，并使用HVSR与弹性动力学Green函数之间的关系。该代码包含3个全局(蒙特卡罗采样，模拟退火和改进模拟退火)和2个局部(单纯形下坡，内部点)反演方法。三个具有不同属性的测试组和所有5种倒置方法进行了检查，以测试软件的各种功能。利用前几次的经验进行最后的测试，实现了低失配的反演。
{"title":"Combination of Passive and Active Methods Towards Site Characterization of Accelerometer Stations in Greece","authors":"G. Papadopoulos, ILIAS FIKOS, A. García-Jerez, N. Theodoulidis, G. Vargemezis","doi":"10.3997/2214-4609.202120124","DOIUrl":"https://doi.org/10.3997/2214-4609.202120124","url":null,"abstract":"Summary The present work deals with the inversion of HVSR. curves to obtain shear wave velocity profiles and how a priori information could be incorporated to facilitate the H/V inversion procedure. The inversion is conducted using the “HV-Inv” computer code (Garcia-Jerez et al., 2016), which is based on the Diffuse Field Assumption and uses the relation between the HVSR and the elastodynamic Green’s function. This code is packed with 3 global (Monte Carlo sampling, Simulated Annealing and Modified Simulated Annealing) and 2 local (Simplex Downhill, Interior Point) inversion methods. Three test groups with different properties and with all 5 inversions methods are examined to test various capabilities of the software. A final test is conducted using the experience of the previous ones, achieving inversions with lower misfit.","PeriodicalId":418930,"journal":{"name":"NSG2021 2nd Conference on Geophysics for Infrastructure Planning, Monitoring and BIM","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122828515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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