Amir Kaynia | NGI - Academia.edu (original) (raw)
Papers by Amir Kaynia
Geotechnical Engineering for Transportation Projects, 2004
ABSTRACT The paper discusses the geodynamic challenges in high speed and high axle load railway p... more ABSTRACT The paper discusses the geodynamic challenges in high speed and high axle load railway projects, especially for soft ground conditions. Three main issues need to be solved by the engineering community: critical speed and excessive dynamic response of the track structure and supporting ground, accelerated degradation of the track structure, and vibration in track-side dwellings and buildings that can inconvenience people and disturb sensitive equipment. The paper describes the nature of these three issues and discusses the prediction tools and design strategies. The importance of knowledge on the ground characteristics, especially the dynamic properties, is emphasized. Countermeasures are discussed. Further needs are pointed out, including the most urgent needs for further research and development. The benefit of standardized solutions, international collaboration projects and the sharing of knowledge is highlighted.
The slope stability behaviour of cohesive and cohesionless soil slopes was evaluated under earthq... more The slope stability behaviour of cohesive and cohesionless soil slopes was evaluated under earthquakes with different frequencies and amplitudes (0.01 to 1.0 g). The study focused on the computation of slope instability thresholds at different slope heights (5, 10 and 15 m) and inclinations. This parametric analysis was performed with a nonlinear finite element method (FEM) in plane strain using
Offshore Technology Conference, 2007
Soil Dynamics and Earthquake Engineering, 1993
A general methodology is outlined for a complete seismic soil-pile-foundationstructure interactio... more A general methodology is outlined for a complete seismic soil-pile-foundationstructure interaction analysis. A Beam-on-Dynamic-Winkler-Foundation (BDWF) simplified model and a Green's-function-based rigorous method are utilized in determining the dynamic response of single piles and pile groups. The simplified model is validated through comparisons with the rigorous method. A comprehensive parameter study is then performed on the effect of pile group configuration on the dynamic impedances of pile foundations. Insight is gained into the nature of dynamic pile-soil-pile interaction. The results presented herein may be used in practice as a guide in obtaining the dynamic stiffness and damping of foundations with a large number of piles.
Rock Mechanics and Rock Engineering, 2012
Stability analysis of Surabhi landslide in the Dehradun and Tehri districts of Uttaranchal locate... more Stability analysis of Surabhi landslide in the Dehradun and Tehri districts of Uttaranchal located in Mussoorie, India, has been simulated numerically using the distinct element method focusing on the weak zones (fracture). This is an active landslide on the main road toward the town centre, which was triggered after rainfall in July-August 1998. Understanding the behaviour of this landslide will be helpful for planning and implementing mitigation measures. The first stage of the study includes the total area of the landslide. The area identified as the zone of detachment is considered the most vulnerable part of the landslide. Ingress of water and increased pore pressures result in reduced mobilized effective frictional resistance, causing the top layer of the zone of detachment to start moving. The corresponding total volume of rock mass that is potentially unstable is estimated to 11.58 million m 3 . The second stage of this study includes a 2D model focussing only on the zone of detachment. The result of the analyses including both static and dynamic loading indicates that most of the total displacement observed in the slide model is due to the zone of detachment. The discontinuum modelling in the present study gives reasonable agreement with actual observations and has improved understanding of the stability of the slide slope.
International Journal of Rock Mechanics and Mining Sciences, 2004
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992
Engineering Geology, 2004
Static and dynamic rock slope stability analyses were performed using a numerical discontinuum mo... more Static and dynamic rock slope stability analyses were performed using a numerical discontinuum modelling technique for a 700-m high rock slope in western Norway. The rock slope has been investigated by the Geological Survey of Norway (NGU), which has been carrying out rock slide studies for the county Møre and Romsdal in western Norway. The purpose of numerical modelling was to estimate the volume of the rock mass that could potentially slide under static and dynamic forces. This estimation was required to assess the run-up heights (tsunami) in a fjord that could potentially be caused by the rockslide. Three cases have been simulated for predicting the behaviour of the rock slope. First, an initial static loading is applied in the numerical model to simulate the prevailing rock mass conditions at the site. Second, saturated and weathered joint conditions are modelled by reducing the residual friction angle along the discontinuities of the rock mass. In doing so, the model simulates the effect of degradation of discontinuities in the rock slope. Third, a dynamic loading, based on peak ground accelerations expected in the area, is applied to simulate dynamic earthquake conditions. These numerical studies have provided some useful insights into the deformation mechanisms in the rock slope. Both sliding and rotation of blocks start to occur once the residual friction angle along the discontinuities is reduced and when the region is shaken by a strong earthquake. The results indicate that, due to variations in the inclination of discontinuities, the entire slope does not become unstable and that down-slope sliding and rotation of blocks occur mainly on the top layers of the slope. Within the range of parameter values considered for this study, it is unlikely that the whole rock slope can be destabilised. The study provides an illustration of how the geo-mechanical properties of a rock mass can be integrated in a discontinuum rock slope model, which is used for predicting the behaviour of the slope under existing environmental and earthquake conditions. This model has helped not only to better understand the dynamics of the rockslide but also to estimate the potential rock volume that can become unstable when subjected to static and dynamic loads. D
Engineering Geology, 2008
The paper illustrates a method for scenario-based, quantitative estimation of physical vulnerabil... more The paper illustrates a method for scenario-based, quantitative estimation of physical vulnerability of the built environment to landslides. The rationale and main features of the procedure are presented in the context of quantitative risk estimation. Vulnerability is defined quantitatively as a function of landslide intensity and the susceptibility of vulnerable elements. Reference terminology is presented and discussed. Models for the quantification of intensity and susceptibility for some categories of elements at risk such as structures and persons are proposed. An example application is illustrated.
Earthquake Spectra, 2009
A seismic risk assessment methodology based on socio-economic clustering of urban habitat is pres... more A seismic risk assessment methodology based on socio-economic clustering of urban habitat is presented in this paper. In this methodology, the city is divided into different housing clusters based on socio-economic level of occupants, representing reasonably uniform seismic risk. It makes an efficient utilization of high resolution satellite data and stratified random sample survey to develop the building stock database. Ten different classes of socio-economic clusters found in Indian cities are defined and 34 Model Building Types (MBTs) prevalent on the Indian subcontinent have been identified and compared with MSK, EMS, PSI and HAZUS classifications. Lower and upper bound Damage Probability Matrices (DPMs) are estimated, based on the MSK and EMS intensity scales, and experience from past earthquakes in India. A case study of Dehradun city in the foothills of Himalayas is presented. The risk estimates using the estimated DPMs
eqrisk.info
Landslides are one of the frequently occurring natural hazards in seismically active North-West p... more Landslides are one of the frequently occurring natural hazards in seismically active North-West part of Indian Himalayas. In this study, an endeavour has been made to model Surbhee Landslide (longitudes 78o02 ' and 78o04 ' E and latitudes 30o28 ' and 30o31 ' N) in the Dehradun ...
eqrisk.info
Numerical experiments are conducted for investigating the effect of seismicity on rock support in... more Numerical experiments are conducted for investigating the effect of seismicity on rock support in tunnels of different sizes. It is shown that for elastic-perfectly plastic materials (eg weak rock mass) the maximum axial force on the tunnel lining increases significantly when ...
Applied Acoustics, 2005
An extensive program of intermediate and long range impulsive sound propagation field tests have ... more An extensive program of intermediate and long range impulsive sound propagation field tests have been conducted. The test program and the performed measurements are presented. Particular focus is given on the air-ground interaction and its effect on low frequency sound and vibration propagation. It is found that the pressure wave interaction with the viscoelastic Rayleigh wave in the ground may have a significant effect on the ground impedance and the sound and vibration propagation. This introduces an important mechanism not covered in commonly used ground impedance models. Numerical simulation models have been developed and verified against the test data. The ground impedance does not only effect the sound pressure propagation. If either acoustically induced ground vibration, or ground to building transmitted vibration, is to be considered, the acousto-seismic impedance has a dramatic effect on the level of ground vibration induced by a given sound pressure. For a site where Rayleigh wave interaction appears at the dominant frequencies of the sound pressure, the ground 0003-682X/$ -see front matter Ó Applied Acoustics 66 www.elsevier.com/locate/apacoust vibration may be greater than a factor 100 (40 dB) than at a site with ground conditions not making the interaction happen.
eqrisk.info
In the present study an endeavour has been made to model Surabhi Landslide (longitudes 78o02'... more In the present study an endeavour has been made to model Surabhi Landslide (longitudes 78o02' and 78o04'E and latitudes 30o28' and 30o31'N) in the Dehradun and Tehri districts of Uttaranchal located in Mussoorie, India. 2-D model has been simulated to understand the ...
The performance of underground structures such as rail, road and hydropower tunnels in seismic re... more The performance of underground structures such as rail, road and hydropower tunnels in seismic regions can be adversely affected. Several cases have been reported on damages to underground structures during earthquake events. The damages reported have been fallen lining from ...
Publications Office of the European Union, Jan 1, 2013
It is an essential step in urban earthquake risk assessment to compile inventory databases of ele... more It is an essential step in urban earthquake risk assessment to compile inventory databases of elements at risk and to make a classification on the basis of pre-defined typology/taxonomy definitions. Typology definitions and the classification system should reflect the vulnerability characteristics of the systems at risk, e.g. buildings, lifeline networks, transportation infrastructures, etc., as well as of their sub-components in order to ensure a uniform interpretation of data and risk analyses results. In this report, a summary of literature review of existing classification systems and taxonomies of the European physical assets at risk is provided in Chapter 2. The identified main typologies and the classification of the systems and their sub-components, i.e. SYNER-G taxonomies, for Buildings, Utility Networks, Transportation Infrastructures and Critical Facilities are presented in Chapters 3, 4, 5 and 6, respectively.
Geotechnical Engineering for Transportation Projects, 2004
ABSTRACT The paper discusses the geodynamic challenges in high speed and high axle load railway p... more ABSTRACT The paper discusses the geodynamic challenges in high speed and high axle load railway projects, especially for soft ground conditions. Three main issues need to be solved by the engineering community: critical speed and excessive dynamic response of the track structure and supporting ground, accelerated degradation of the track structure, and vibration in track-side dwellings and buildings that can inconvenience people and disturb sensitive equipment. The paper describes the nature of these three issues and discusses the prediction tools and design strategies. The importance of knowledge on the ground characteristics, especially the dynamic properties, is emphasized. Countermeasures are discussed. Further needs are pointed out, including the most urgent needs for further research and development. The benefit of standardized solutions, international collaboration projects and the sharing of knowledge is highlighted.
The slope stability behaviour of cohesive and cohesionless soil slopes was evaluated under earthq... more The slope stability behaviour of cohesive and cohesionless soil slopes was evaluated under earthquakes with different frequencies and amplitudes (0.01 to 1.0 g). The study focused on the computation of slope instability thresholds at different slope heights (5, 10 and 15 m) and inclinations. This parametric analysis was performed with a nonlinear finite element method (FEM) in plane strain using
Offshore Technology Conference, 2007
Soil Dynamics and Earthquake Engineering, 1993
A general methodology is outlined for a complete seismic soil-pile-foundationstructure interactio... more A general methodology is outlined for a complete seismic soil-pile-foundationstructure interaction analysis. A Beam-on-Dynamic-Winkler-Foundation (BDWF) simplified model and a Green's-function-based rigorous method are utilized in determining the dynamic response of single piles and pile groups. The simplified model is validated through comparisons with the rigorous method. A comprehensive parameter study is then performed on the effect of pile group configuration on the dynamic impedances of pile foundations. Insight is gained into the nature of dynamic pile-soil-pile interaction. The results presented herein may be used in practice as a guide in obtaining the dynamic stiffness and damping of foundations with a large number of piles.
Rock Mechanics and Rock Engineering, 2012
Stability analysis of Surabhi landslide in the Dehradun and Tehri districts of Uttaranchal locate... more Stability analysis of Surabhi landslide in the Dehradun and Tehri districts of Uttaranchal located in Mussoorie, India, has been simulated numerically using the distinct element method focusing on the weak zones (fracture). This is an active landslide on the main road toward the town centre, which was triggered after rainfall in July-August 1998. Understanding the behaviour of this landslide will be helpful for planning and implementing mitigation measures. The first stage of the study includes the total area of the landslide. The area identified as the zone of detachment is considered the most vulnerable part of the landslide. Ingress of water and increased pore pressures result in reduced mobilized effective frictional resistance, causing the top layer of the zone of detachment to start moving. The corresponding total volume of rock mass that is potentially unstable is estimated to 11.58 million m 3 . The second stage of this study includes a 2D model focussing only on the zone of detachment. The result of the analyses including both static and dynamic loading indicates that most of the total displacement observed in the slide model is due to the zone of detachment. The discontinuum modelling in the present study gives reasonable agreement with actual observations and has improved understanding of the stability of the slide slope.
International Journal of Rock Mechanics and Mining Sciences, 2004
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992
Engineering Geology, 2004
Static and dynamic rock slope stability analyses were performed using a numerical discontinuum mo... more Static and dynamic rock slope stability analyses were performed using a numerical discontinuum modelling technique for a 700-m high rock slope in western Norway. The rock slope has been investigated by the Geological Survey of Norway (NGU), which has been carrying out rock slide studies for the county Møre and Romsdal in western Norway. The purpose of numerical modelling was to estimate the volume of the rock mass that could potentially slide under static and dynamic forces. This estimation was required to assess the run-up heights (tsunami) in a fjord that could potentially be caused by the rockslide. Three cases have been simulated for predicting the behaviour of the rock slope. First, an initial static loading is applied in the numerical model to simulate the prevailing rock mass conditions at the site. Second, saturated and weathered joint conditions are modelled by reducing the residual friction angle along the discontinuities of the rock mass. In doing so, the model simulates the effect of degradation of discontinuities in the rock slope. Third, a dynamic loading, based on peak ground accelerations expected in the area, is applied to simulate dynamic earthquake conditions. These numerical studies have provided some useful insights into the deformation mechanisms in the rock slope. Both sliding and rotation of blocks start to occur once the residual friction angle along the discontinuities is reduced and when the region is shaken by a strong earthquake. The results indicate that, due to variations in the inclination of discontinuities, the entire slope does not become unstable and that down-slope sliding and rotation of blocks occur mainly on the top layers of the slope. Within the range of parameter values considered for this study, it is unlikely that the whole rock slope can be destabilised. The study provides an illustration of how the geo-mechanical properties of a rock mass can be integrated in a discontinuum rock slope model, which is used for predicting the behaviour of the slope under existing environmental and earthquake conditions. This model has helped not only to better understand the dynamics of the rockslide but also to estimate the potential rock volume that can become unstable when subjected to static and dynamic loads. D
Engineering Geology, 2008
The paper illustrates a method for scenario-based, quantitative estimation of physical vulnerabil... more The paper illustrates a method for scenario-based, quantitative estimation of physical vulnerability of the built environment to landslides. The rationale and main features of the procedure are presented in the context of quantitative risk estimation. Vulnerability is defined quantitatively as a function of landslide intensity and the susceptibility of vulnerable elements. Reference terminology is presented and discussed. Models for the quantification of intensity and susceptibility for some categories of elements at risk such as structures and persons are proposed. An example application is illustrated.
Earthquake Spectra, 2009
A seismic risk assessment methodology based on socio-economic clustering of urban habitat is pres... more A seismic risk assessment methodology based on socio-economic clustering of urban habitat is presented in this paper. In this methodology, the city is divided into different housing clusters based on socio-economic level of occupants, representing reasonably uniform seismic risk. It makes an efficient utilization of high resolution satellite data and stratified random sample survey to develop the building stock database. Ten different classes of socio-economic clusters found in Indian cities are defined and 34 Model Building Types (MBTs) prevalent on the Indian subcontinent have been identified and compared with MSK, EMS, PSI and HAZUS classifications. Lower and upper bound Damage Probability Matrices (DPMs) are estimated, based on the MSK and EMS intensity scales, and experience from past earthquakes in India. A case study of Dehradun city in the foothills of Himalayas is presented. The risk estimates using the estimated DPMs
eqrisk.info
Landslides are one of the frequently occurring natural hazards in seismically active North-West p... more Landslides are one of the frequently occurring natural hazards in seismically active North-West part of Indian Himalayas. In this study, an endeavour has been made to model Surbhee Landslide (longitudes 78o02 ' and 78o04 ' E and latitudes 30o28 ' and 30o31 ' N) in the Dehradun ...
eqrisk.info
Numerical experiments are conducted for investigating the effect of seismicity on rock support in... more Numerical experiments are conducted for investigating the effect of seismicity on rock support in tunnels of different sizes. It is shown that for elastic-perfectly plastic materials (eg weak rock mass) the maximum axial force on the tunnel lining increases significantly when ...
Applied Acoustics, 2005
An extensive program of intermediate and long range impulsive sound propagation field tests have ... more An extensive program of intermediate and long range impulsive sound propagation field tests have been conducted. The test program and the performed measurements are presented. Particular focus is given on the air-ground interaction and its effect on low frequency sound and vibration propagation. It is found that the pressure wave interaction with the viscoelastic Rayleigh wave in the ground may have a significant effect on the ground impedance and the sound and vibration propagation. This introduces an important mechanism not covered in commonly used ground impedance models. Numerical simulation models have been developed and verified against the test data. The ground impedance does not only effect the sound pressure propagation. If either acoustically induced ground vibration, or ground to building transmitted vibration, is to be considered, the acousto-seismic impedance has a dramatic effect on the level of ground vibration induced by a given sound pressure. For a site where Rayleigh wave interaction appears at the dominant frequencies of the sound pressure, the ground 0003-682X/$ -see front matter Ó Applied Acoustics 66 www.elsevier.com/locate/apacoust vibration may be greater than a factor 100 (40 dB) than at a site with ground conditions not making the interaction happen.
eqrisk.info
In the present study an endeavour has been made to model Surabhi Landslide (longitudes 78o02'... more In the present study an endeavour has been made to model Surabhi Landslide (longitudes 78o02' and 78o04'E and latitudes 30o28' and 30o31'N) in the Dehradun and Tehri districts of Uttaranchal located in Mussoorie, India. 2-D model has been simulated to understand the ...
The performance of underground structures such as rail, road and hydropower tunnels in seismic re... more The performance of underground structures such as rail, road and hydropower tunnels in seismic regions can be adversely affected. Several cases have been reported on damages to underground structures during earthquake events. The damages reported have been fallen lining from ...
Publications Office of the European Union, Jan 1, 2013
It is an essential step in urban earthquake risk assessment to compile inventory databases of ele... more It is an essential step in urban earthquake risk assessment to compile inventory databases of elements at risk and to make a classification on the basis of pre-defined typology/taxonomy definitions. Typology definitions and the classification system should reflect the vulnerability characteristics of the systems at risk, e.g. buildings, lifeline networks, transportation infrastructures, etc., as well as of their sub-components in order to ensure a uniform interpretation of data and risk analyses results. In this report, a summary of literature review of existing classification systems and taxonomies of the European physical assets at risk is provided in Chapter 2. The identified main typologies and the classification of the systems and their sub-components, i.e. SYNER-G taxonomies, for Buildings, Utility Networks, Transportation Infrastructures and Critical Facilities are presented in Chapters 3, 4, 5 and 6, respectively.