Nonlinear Site Effects: Interest Of One Directional - Three Component (1d - 3c) Formulation,
2010
Université Paris-Est, France
Nonlinear Site Effects: Interest Of One Directional - Three Component (1d - 3c) Formulation, Maria Paola Santisi D’Avila, Jean-François Semblat, Ali Gandomzadeh, Fabian Bonilla, Luca Lenti, Salvatore Martino
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Strong ground motions generally lead to both a stiffness reduction and a larger energy dissipation in the soil layers. Thus, in order to study such phenomena, several nonlinear rheologies have been developed in the past. However, one of the main difficulties of using a given rheology is the number of parameters needed to describe the model. In this sense, the multi-surface cyclic plasticity approach, developed by Iwan in 1967 is an interesting choice since the only data needed is the modulus reduction curve. Past studies have implemented this method in one-directional SH wave-propagation (1D-1C). This work, however, aims to study …
Evaluation Of Frequency Dependent Equivalent Linear Analysis,
2010
Hanyang University, Seoul, Korea
Evaluation Of Frequency Dependent Equivalent Linear Analysis, Chang-Gyun Jeong, Dong-Yeop Kwak, Duhee Park, Kwangkyun Kim
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
One dimensional equivalent linear site response analysis is widely used in practice due to the simplicity and ease of use. In the method, the dynamic soil properties are assumed to be independent of the loading frequency. To better simulate the nonlinear behavior, equivalent analysis methods that models the loading frequency dependence of the shear modulus and damping were developed. The backbone of the methods is the frequency-dependent shear strain curves. Various forms of the frequency-dependent shear strain curves were developed. However, the effect of the frequency - shear strain curves are not well known and documented. In this study, a …
Site-Specific Response Analysis In The New Madrid Seismic Zone,
2010
Black & Veatch Corporation, Overland Park, KS
Site-Specific Response Analysis In The New Madrid Seismic Zone, Wei Zheng, Youssef Hashash, Mark M. Petersen, Andrew S. Whittaker
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A coal-fired power plant, Plum Point Energy Station, is being built in the city of Osceola, Arkansas, which is located in the New Madrid Seismic Zone (NMSZ). The project site is characterized as Site Class F, according to ASCE-7-05, because the soils at the site are prone to liquefaction. The depth of soil to rock is approximately 1 kilometer (km). A site-specific response study was required by the building code to determine the uniform hazard spectrum at the ground surface. The site-specific study included a probabilistic seismic hazard assessment to determine the Maximum Considered Earthquake (MCE) spectrum at an equivalent …
The Limitations Of Equivalent Linear Site Response Analysis Considering Soil Nonlinearity Properties,
2010
Amirkabir University of Technology (Tehran Polytechnic), Iran
The Limitations Of Equivalent Linear Site Response Analysis Considering Soil Nonlinearity Properties, S. M. Mir Mohammad Hosseini, M. Asadolahi Pajouh, F. Mir Mohammad Hosseini
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic site effect has been a major issue in the field of earthquake engineering due to the large local amplification of the seismic motion. This paper presents the importance of an appropriate soil behavior model to simulate earthquake site response and gives a critical overview of the field of site response analysis. Some of the well known site response analysis methods are summarized and discussed. The objective of this paper is to investigate the influences of nonlinearity on the site response analysis by means of a more precise numerical model. In this respect, site responses of four different types of …
Site Response Study Of Deep Soil Column In Lucknow, India,
2010
Indian Institute of Science, India
Site Response Study Of Deep Soil Column In Lucknow, India, P. Anbazhagan, Abhishek Kumar, T. G. Sitharam
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Earthquake activities in the many parts of world had shown the importance of local soil condition in the propagated wave motion. In this paper an attempt has been made to estimate site effects of deep soil column in Lucknow, Indo-Gangetic basin for scenario earthquakes at Himalayan plate boundary. Based on previous study, the synthetic ground motion has been generated using Stochastic Finite Fault model (FINSIM) for two scenario earthquakes at seismic gaps. One seismic gap called as western location/seismic gap is located about 307.88km from site and gives the peak ground acceleration of 0.11g at site. Another one is the …
A Study Of Effective Factors On The Behavioural Characteristics Of Clayey Sands,
2010
Tarbiat Modares University, Iran
A Study Of Effective Factors On The Behavioural Characteristics Of Clayey Sands, Omid Naeemifar, S. Shahaboddin Yasrobi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
As in recent years liquefaction phenomena have occurred in sandy soils containing different amounts of clay contents, it was concluded that in addition to silty sands, clayey sands are also vulnerable to liquefaction phenomenon. So, the urge for comprehensive study aroused to cover the issue. In this paper, the effect of clay content and its plasticity properties on behavioural characteristics of clayey sands under various density and confining pressure values have been investigated. To achieve the goal, about a hundred monotonic triaxial tests were performed on remoulded specimens of sandy soils containing different clay contents with different plasticity values. Based …
Site Specific Seismic Analysis Of A Deep Stiff Soil Site,
2010
Indian Institute of Technology Madras, India
Site Specific Seismic Analysis Of A Deep Stiff Soil Site, S. Krishna Kumar, A. Boominathan
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Site specific analysis was carried out for a deep stiff soil site located near Ahmedabad, India. The site predominantly consists of sandy clay and silty sand layer in the top 30m with Vs varying from 430 to 750m/s. It is followed by a high plastic stiff clay layer cemented with sand and gravel with unusually high Vs above 1000m/s. The study region surrounded by 13 major faults has experienced several major earthquakes including the disastrous Bhuj earthquake (Mw=7.7). The seismic hazard level at the site was estimated by deterministic approach and the East Cambay fault with Mw of …
A Note On The Effect Of Non-Plastic Fines On The Liquefaction And Reconsolidation Volumetric Strain Behaviour Of Sands,
2010
Indian Institute of Science, India
A Note On The Effect Of Non-Plastic Fines On The Liquefaction And Reconsolidation Volumetric Strain Behaviour Of Sands, T. G. Sitharam, B. V. Ravishankar, J. S. Vinod
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper discusses the influence of non- plastic fines on the liquefaction and reconsolidation volumetric strain behaviour of sand based on the strain controlled cyclic triaxial experimental results. The investigations were carried out on sand samples collected from earthquake-affected area of Ahmedabad city of Gujarat state in India. Laboratory investigations were conducted on clean sand (prepared from the natural sand) samples with varying amount of non-plastic fines. Experimental results highlight a considerable influence of non-plastic fines on the resistance to liquefaction and reconsolidation volumetric strains behaviour during cyclic loading.
Application Of General Regression Neural Networks (Grnns) In Assessing Liquefaction Susceptibility,
2010
Housing & Building Research Center, Egypt
Application Of General Regression Neural Networks (Grnns) In Assessing Liquefaction Susceptibility, Suzan S. Salem, Khalid El-Zahaby
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Liquefaction is considered among the most important hazards associated with earthquakes. The damage resulting from seismic liquefaction may be huge; thus, there always exists needs to mitigate the damage associated with such risks. One of the main problems challenging geotechnical engineers is how to assess the seismic liquefaction hazard. Statistical and probabilistic approaches for seismic liquefaction are currently available. In this paper, a general regression neural networks approach (GRNNs) has been used to assess the liquefaction hazard in Egypt. Thus, data from new locations can be analyzed using GRNNs to obtain the liquefaction risk associated with this new site. The …
Weak Motion Linear Soil Amplification At Aegion, Greece, And Comparison With Seismic Design Codes,
2010
Aristotle University Thessaloniki, Greece
Weak Motion Linear Soil Amplification At Aegion, Greece, And Comparison With Seismic Design Codes, Olga-Joan Ktenidou, Dimitris Raptakis, Kyriazis Pitilakis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
We use 473 weak motion surface records from a relatively soft soil site (CORSSA) and 81 from a relatively stiff soil site (DIM) in conjunction with downhole records obtained in rock in order to study linear seismic soil amplification in Aegion, Greece. We estimate peak ‘soil-to-outcrop’ amplification factors in the time domain for the two sites through linear regression of PGA values. We view the results derived from these very weak motion records as indicative of the entire linear elastic range based on the large dataset size. We compare the peak horizontal soil amplification factors we derive from records with …
Artificial Neural Network Model For Prediction Of Liquefaction Potential In Soil Deposits,
2010
Babol Noshirvani University of Technology, Iran
Artificial Neural Network Model For Prediction Of Liquefaction Potential In Soil Deposits, F. Farrokhzad, A. J. Choobbasti, A. Barari
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
With the increase in population, the evaluation of liquefaction is becoming more important for land use planning and development. In soil deposits under undrained condition, earthquakes induce cyclic shear stresses, may lead to soil liquefaction. Artificial neural network (ANN) is one of the, artificial intelligence (AI) approaches that can be classified as machine learning. Simplified methods have been practiced by researchers to assess nonlinear liquefaction potential of soil. In order to address the collective knowledge built up in conventional liquefaction engineering, an alternative general regression neural network model is proposed in this paper. To meet this objective, a total of …
Assessment Of Liquefaction Potential Relevant To Choice Of Type And Depth Of Foundations In Seismically Active Areas,
2010
University of Belgrade, Republic of Serbia
Assessment Of Liquefaction Potential Relevant To Choice Of Type And Depth Of Foundations In Seismically Active Areas, Hadži-Niković D. Gordana, Perković D. Ilija, Abolmasov Biljana
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
There is evidence of great increase of pore pressures in saturated sand soils during cyclic loading caused by earthquakes. These increased pore pressures can often increase to effective stresses in soil. Dependant on sand density, this can lead to a total loss of shear strength, liquefaction or greater deformability of soil. Emergence of liquefaction or great deformations within soil can cause significant damage or total destruction of constructions on the ground, even when they have been correctly designed. For this reason, it is very important to perform detailed geotechnical and seismic investigations of ground conditions and evaluate liquefaction potential for …
Fem Modelling Of A 3d Soil-Pile System Under Earthquakes,
2010
University of Catania, Italy
Fem Modelling Of A 3d Soil-Pile System Under Earthquakes, Francesco Grassi, Maria Rossella Massimino
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During earthquakes seismic wave crossing through soft soil can lead to significant curvatures on pile foundations, which in turn lead to significant bending moments. These bending moments are commonly named “kinematic bending moments”, to be distinguished from the “inertial bending moments” due to horizontal forces transferred from superstructures to pile heads. Approaches to carefully evaluate inertial bending moments have been recently developed world-wide; but the evaluation of the kinematic bending moments is still questionable. In this paper a 3D soil-pile FEM system is analysed. The system is subjected to seismic input motions, applied at the base of the system, which …
Lateral Response Of Bridge Pile Groups In Liquefiable Soil With Surface Non-Liquefiable Layer Using Shaking Table Test,
2010
Harbin Institute of Technology Harbin, China
Lateral Response Of Bridge Pile Groups In Liquefiable Soil With Surface Non-Liquefiable Layer Using Shaking Table Test, Tang Liang, Ling Xianzhang, Xu Pengju, Gao Xia
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper conducts a shaking table test study on seismic response of low-cap pile groups and bridge structure in liquefiable ground. The soil profile in the test consisted of the horizontal saturated sand layer overlaid the silty clay layer. The base was excited by three different El Centro earthquake events. The preliminary liquefaction characteristics of ground firstly were analyzed. The bending moment of the pile was mainly introduce in the note. There’s no doubt that the shaking table test provided the necessary groundwork to study lateral response of bridge pile groups in liquefiable soil with surface non-liquefiable layer.
Investigation Of Vibration Caused By Traffic And Railway Load,
2010
University of Belgrade, Republic of Serbia
Investigation Of Vibration Caused By Traffic And Railway Load, Hadži-Niković D. Gordana, Ćorić B. Stanko
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Two examples related to investigation of vibrations in civil engineering structures are presented. In the first example it is shown how it is possible to decrease vibration in underground structures. These vibrations are caused by train load. It is shown by the results of presented dynamic analysis that the use of special elastomer is very important in engineering practice in order to decrease structural vibrations. Second example presents the foundation for special equipment - eletronic balances, which are very sensetive, even to small displacement. Presented dynamic analysis is related to the vibrations caused by heavy traffic load in order to …
Modeling The Influence Of Soil Structure Interaction On The Seismic Response Of A 5 Mw Wind Turbine,
2010
University of California, San Diego, La Jolla, CA
Modeling The Influence Of Soil Structure Interaction On The Seismic Response Of A 5 Mw Wind Turbine, Ian Prowell, Ahmed Elgamal, Jinchi Lu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In order to capture more energy, wind turbines are rapidly growing in height and rotor size. This growth increases the likelihood that soil structure interaction effects may influence the structural dynamic response. Current 3 MW turbines tower over the landscape with an 80 meter hub height and a 90 meter rotor diameter. This paper models a full soil structure system for the National Renewable Energy Laboratory onshore 5 MW reference wind turbine with a hub height of 90 meter and a 126 meter rotor diameter. A detailed finite element model of the turbine is created, including a full three dimensional …
Influence Of Soil-Structure Interaction On Seismic Response Of Shear Buildings,
2010
University of Florence, Italy
Influence Of Soil-Structure Interaction On Seismic Response Of Shear Buildings, Stefano Renzi, George Mylonakis, Giovanni Vannucchi, Claudia Madiai
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The beneficial or detrimental effect of dynamic Soil-Structure Interaction (SSI) is a controversial issue. With reference to an idealized R/C shear building, a comprehensive comparison between the results obtained with a classical fixed-base analysis and a complete SSI analysis is provided in the present paper. The shear-type structure is modeled as generalized Single Degree Of Freedom (SDOF) system using the principle of virtual displacements. The foundation consists of surface square foundations resting on different soil conditions, consistent with the provisions of EC8-part I. SSI effects in the far-field of earthquakes was evaluated by direct application of the elastic pseudo-acceleration/displacement design …
Effects Of Soil-Structure Interaction On Stress Distribution Within A Pile Group Under Multi-Dimensional Loading,
2010
Tokyo Institute of Technology, Japan
Effects Of Soil-Structure Interaction On Stress Distribution Within A Pile Group Under Multi-Dimensional Loading, Hiroko Suzuki, Kohji Tokimatsu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
To investigate inertial and kinematic effects on stress distributions within a pile group, physical model tests were conducted at EDefense, one of the largest shaking table facilities in the world. A 3x3 steel pile group supporting a foundation with a superstructure was set in a dry sand deposit prepared in a cylindrical laminar box with a height of 6.5 m and a diameter of 8.0 m. Natural periods of superstructures were variable in the tests. The tests were conducted under one-, two- or three-dimensional shaking. The test results have shown that pile stresses were mainly controlled by the inertial force …
Non-Stationary Soil-Structure Interaction Analysis Of A Sdof System Subjected To Joint Horizontal And Vertical Seismic Excitations,
2010
TNO Diana B.V., The Netherlands
Non-Stationary Soil-Structure Interaction Analysis Of A Sdof System Subjected To Joint Horizontal And Vertical Seismic Excitations, Pranesh Chatterjee, Biswajit Basu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper a formulation has been presented to obtain the non-stationary response of a single degree of freedom system resting on a single layered soil medium and subjected to simultaneous horizontal and vertical seismic excitations. The wavelet based analytical technique using the modified Littlewood-Paley function has been adopted to characterize the seismic ground motions. Subsequently, the system equations have been solved in wavelet domain and closed form solutions for the response of the structure have been derived. The response has been calculated using wavelet based formulation and the traditional complex valued transfer function. A numerical example is also presented …
Influence Of Soil Nonlinearities On Dynamic Soil-Structure Interaction,
2010
Université Paris-Est, Laboratoire Central des Ponts et Chaussées (LCPC), France
Influence Of Soil Nonlinearities On Dynamic Soil-Structure Interaction, Ali Gandomzadeh, Luca Lenti, Maria Paola Santisi D’Avila, Fabian Bonilla, Jean-François Semblat
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
For moderate or strong seismic events, the maximum strains can easily reach the elastic limit of the soil behavior. Considering soilstructure interaction, the nonlinear effects may change the soil stiffness at the base of the structure and the energy dissipation into the soil. To take into account the nonlinearity of the soil in the dynamic soil-structure interaction (DSSI), a 3D constitutive model, proposed by Iwan, is used to investigate DSSI in the framework of the Finite Element Method. The model accounts for the nonlinear hysteretic behavior of soils and only needs the shear modulus degradation curve to characterize the soil …
