Open Access. Powered by Scholars. Published by Universities.®

Geotechnical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type

Articles 331 - 360 of 432

Full-Text Articles in Geotechnical Engineering

Centrifuge Model Tests Of Tieback Anchors And Drainage Pipes For Stabilization Of Slopes Under Earthquake Loads, Keiichi Ota, Koji Takeya, Keiichi Itoh, Senro Kuraoka, Yuichi Ueno, Takaya Hiroshima May 2010

Centrifuge Model Tests Of Tieback Anchors And Drainage Pipes For Stabilization Of Slopes Under Earthquake Loads, Keiichi Ota, Koji Takeya, Keiichi Itoh, Senro Kuraoka, Yuichi Ueno, Takaya Hiroshima

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Tieback anchors are widely used for the stabilization of natural and manmade slopes in Japan. The interactions between tieback anchors and slopes under seismic loading need to be understood to develop rational design concepts and installation methods in earthquake prone areas. We conducted centrifuge model tests to examine the characteristics of dynamic and residual loads on tieback anchors installed in slopes subjected to seismic loads. If the model slope contained a saturated zone, circular failure occurred even with pre-tensioned tieback anchors, and the amplitude of the oscillating loads on the tieback anchors was very high. This suggested that excess pore …


Comparison Of Liquefaction Triggering Analysis Approaches For An Embankment Dam And Foundation, David C. Serafini, Vlad Perlea May 2010

Comparison Of Liquefaction Triggering Analysis Approaches For An Embankment Dam And Foundation, David C. Serafini, Vlad Perlea

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Success Dam is located on the Tule River, near the city of Porterville, California. The dam is a rolled earth-fill embankment approximately 145 feet high and 3,400 feet long. The embankment is comprised of a central impervious core protected by upstream and downstream outer pervious zones. A majority of the dam is founded on potentially liquefiable Holocene alluvium. Several analytical techniques of varying complexity have been used to determine the liquefaction potential of the foundation Holocene alluvium and the pervious embankment shells. The following analytical techniques were used on the Success Dam Remediation Project: (1) cyclic stress ratio (CSR) evaluation …


Cyclic Torsional Shear Tests To Obtain Dynamic Soil Properties For Seismic Design Of Road Embankments, Susumu Yasuda, Takafumi Tsuruda May 2010

Cyclic Torsional Shear Tests To Obtain Dynamic Soil Properties For Seismic Design Of Road Embankments, Susumu Yasuda, Takafumi Tsuruda

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Many road embankments have suffered damage during past earthquakes. The authors took soil samples from several embankments and conducted laboratory tests to demonstrate the mechanism of the damages and study appropriate seismic design methods. In the laboratory tests, cyclic torsional shear tests were carried out to obtain undrained cyclic strength, excess pore water pressure and shear modulus after cyclic loading of embankment soils. Test results showed a unique relationship between Plasticity Index and undrained cyclic strength is existed. Relationship between excess pore water pressure ratio and safety factor against liquefaction is also influenced by Plasticity Index. Then appropriate seismic design …


Evaluation Of Seismic Response Of External Mine Overburden Dumps, Radhakanta Koner, Debashish Chakravarty May 2010

Evaluation Of Seismic Response Of External Mine Overburden Dumps, Radhakanta Koner, Debashish Chakravarty

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The stability of mines external overburden dump slope experiencing an earthquake is controlled by deformations; consequently a stability analysis that predicts slope displacements is desirable. The amount of displacement, deformation occur at the crest of the overburden dumps is an important factor for the seismic loading response of the dumps for the field personnel at the mine site for designing the dump slope geometry. The state of effective stress and seismic intensity significantly affects the stability range. In this paper, a simplified approach is presented for the seismic response of overburden dumps, and the role played by relevant parameters such …


Finite Element Modeling Of The Las Colinas Landslide Under Earthquake Shaking, Huynh Dat Vu Khoa, Hans Petter Jostad May 2010

Finite Element Modeling Of The Las Colinas Landslide Under Earthquake Shaking, Huynh Dat Vu Khoa, Hans Petter Jostad

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The Las Colinas landslide that occurred at Santa Tecla (El Salvador, Central America) due to the earthquake of 13 January 2001 is considered as one of the most destructive landslides ever known. This paper studies the ability of Hill’s sufficient condition of stability (1958), which is based on the sign of second-order work, for predicting and describing this catastrophic massive landslide. The general expressions of both local and global second-order work criteria and its implementation into finite element codes are given. By using the non-associated elasto-plastic Hardening Soil Model and the local second-order work criterion, it is demonstrated that potentially …


Geotechnical Characteristics Of Seismically-Induced Aratozawa Landslide, Japan, Ivan Gratchev, Ikuo Towhata May 2010

Geotechnical Characteristics Of Seismically-Induced Aratozawa Landslide, Japan, Ivan Gratchev, Ikuo Towhata

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper seeks to investigate the properties of volcanic soil from the Aratozawa landslide, the largest failure triggered by the 2008 Iwate-Miyagi Nairiku earthquake, Japan. Field investigation was carried out to estimate the in-situ characteristics of volcanic material. It was found that the soil was highly weathered, having low dry density and high moisture content. Laboratory examination included a series of triaxial compression tests which were performed to evaluate the dynamic properties of volcanic soil. Results of undrained cyclic loading tests indicated that the material had a high potential for generation of excess pore-water pressures, which could lead to a …


Numerical Analysis Of Failure Of Rudramatha Dam Section During 26Th January, 2001, Bhuj Earthquake, Amit Srivastava, G. L. Sivakumar Babu May 2010

Numerical Analysis Of Failure Of Rudramatha Dam Section During 26Th January, 2001, Bhuj Earthquake, Amit Srivastava, G. L. Sivakumar Babu

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

On 26th January, 2001, the Kachchh region of Gujarat, India faced devastating earthquake of magnitude 7.6 (Mw) popularly known as “Bhuj” earthquake. Various man made facilities including earthen dams faced varying level of damages during the earthquake and one of the major causes of failure is attributed to wide spread liquefaction of foundation soil. In the present study, a typical Rudramata dam sections located in the Kachchh region is considered for the failure analysis using fully coupled nonlinear dynamic numerical code FLAC 5.0 with pore pressure generation capabilities under dynamic loadings. The analysis is performed using the acceleration …


On The Use Of Empirical Correlations For Estimating The Residual Undrained Shear Strength Of Liquefied Soils In Dam Foundations, David Rees Gillette May 2010

On The Use Of Empirical Correlations For Estimating The Residual Undrained Shear Strength Of Liquefied Soils In Dam Foundations, David Rees Gillette

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Current practice (2009) for seismic analysis of embankment dams relies heavily on empirical correlations with penetration resistance (standard penetration test or cone penetration test) to predict the residual undrained shear strength of liquefied foundation materials. At least six such relationships have been published for the SPT alone, in different “formats.” Some apply a fines adjustment to the SPT blowcounts, but others do not; some express the predicted strength as a ratio with pre-earthquake effective overburden stress, whereas others predict it directly, without explicit consideration of overburden. For the foundations of embankment dams, the difference between the strength-ratio approach and prediction …


Repair Of Landslide "Umka-Duboka" — Seismic Performance Assessment, Vlatko Sesov, Zeljko Zugic May 2010

Repair Of Landslide "Umka-Duboka" — Seismic Performance Assessment, Vlatko Sesov, Zeljko Zugic

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The Umka-Duboko is a large active landslide in the depth of 10-26 m, created in marly clays, taking up the area of 1.8 sq.km. According to the fact that the new road facility corridor located at the right bank of Sava river, on the meandering apex, crosses the landslide in the length of 3 km the characteristic remediation design solution is given. In this paper is observed seismic performance of this project. The analysis of potential liquefaction in motorway embankment and seismic stability of slope retained by embankment and hydraulic structure were made. The necessity was despite the limited seismic …


Seismic Analysis Of The Reservoir-Earth Dam-Pore Fluid System Using An Integrated Numerical Approach, Yanhui Han, Roger Hart May 2010

Seismic Analysis Of The Reservoir-Earth Dam-Pore Fluid System Using An Integrated Numerical Approach, Yanhui Han, Roger Hart

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In this paper, an integrated numerical approach is proposed for analyzing the seismic response of the reservoir-earth dam-pore fluid system subjected to earthquake loading. The fluid-mechanical coupling approach is deployed to capture the fluid-solid matrix coupling effects automatically. A hysteretic damping constitutive law is adopted to follow the modulus reduction and damping ratio curves. The Finn-Byrne equation is used to represent the shear-induced volumetric strain behavior of liquefiable materials. The interaction between the reservoir water and the dam boundary is treated as a dynamically updated pressure boundary condition. The deconvolution is accomplished by the equivalent linear program SHAKE. An automatic …


Seismic Performance Evaluation Of A Submarine Gas Pipeline, Wolfgang H. Roth, C. B. Crouse, Ethan M. Dawson, Bei Su May 2010

Seismic Performance Evaluation Of A Submarine Gas Pipeline, Wolfgang H. Roth, C. B. Crouse, Ethan M. Dawson, Bei Su

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Analyses were conducted on the seismic performance of a proposed offshore gas flowline, which connects a manifold in 830-m water depth to a riser platform in shallow waters of the outer continental shelf. Climbing a 10-degree continental slope, the flowline will be installed on the seafloor underlain by deep carbonate sediments of sands and silty clays. Two types of analyses were performed for a critical segment of the flowline, where it traverses a narrow ridge flanked by two deep submarine canyons: (1) probabilistic analyses using simplified empirical methods; and (2) deterministic 2D and 3D analyses with FLAC using a nonlinear, …


Seismic Stability Assessment The Raising Of The Geita Tailings Storage Facility, Tanzania, Michelle Theron, Fritz Wagener, Phillip Steenkamp May 2010

Seismic Stability Assessment The Raising Of The Geita Tailings Storage Facility, Tanzania, Michelle Theron, Fritz Wagener, Phillip Steenkamp

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The Geita gold mine, owned by AngloGold Ashanti, is located in the north west of Tanzania on the African Rift Belt in a seismically active. It is also located in an environmentally sensitive area as it is directly upslope of Lake Victoria. The Tailings Storage Facility was constructed as a side valley dam with its maximum design embankment elevation 1216m (i.e. 35m above ground level) and store capacity approximately 60 million tons of tailings. The feasibility of increasing this wall ultimately to 1246m (i.e. 65m above ground level) thereby increasing its capacity by 88.5 million tons, is the topic of …


The Effect Of Earthquake Record Scaling Technique On Embankment Dam Response, Hamid Karimian, Somasundaram Sriskandakumar, Adrian Wightman, Li Yan May 2010

The Effect Of Earthquake Record Scaling Technique On Embankment Dam Response, Hamid Karimian, Somasundaram Sriskandakumar, Adrian Wightman, Li Yan

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The state of the practice in dynamic analysis of structures includes the selection of earthquake records based on the mean (or modal) magnitude and distance of the design earthquake, and linearly scaling of the selected records to the target spectral acceleration at the period of significance, or matching the selected records to the uniform hazard response spectrum (UHRS). A method is presented by Baker and Cornell (2005, 2006a, and 2006b) to develop the conditional mean response spectrum of a ground motion given a target value of the spectral acceleration at the period (or period range) of significance. The shape of …


A Parametric Study On Soil-Pile Kinematic Interaction In Layered Soils, Daniela Ardita, Michele Maugeri, Ernesto Motta, Erminia Raciti May 2010

A Parametric Study On Soil-Pile Kinematic Interaction In Layered Soils, Daniela Ardita, Michele Maugeri, Ernesto Motta, Erminia Raciti

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In pile-foundation seismic design, until a few years ago, only inertial loads applied by the overstructure at the pile cap were taked into account, neglecting the dynamic interaction. So, good approaches to evaluate inertial interaction effects have been developed, but not for kinematic interaction. Modern national and international codes require to take into account the dynamic soil-pile-ovestructure interaction (inertial and kinematic), without giving any information about kinematic interaction evaluation criteria. In this work a practical method based on the Winkler foundation model is applied to analyse the seismic response of single piles. The analysis is focused on a single pile …


A Simple Numerical Tool For Dynamic Soil-Structure Interaction Analyses Including Non-Linear Behaviour Of Both Structure And Foundation, R. Figini, C. T. Chatzigogos, R. Paolucci May 2010

A Simple Numerical Tool For Dynamic Soil-Structure Interaction Analyses Including Non-Linear Behaviour Of Both Structure And Foundation, R. Figini, C. T. Chatzigogos, R. Paolucci

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In this paper a simple model to take into account dynamic non-linear soil-structure interaction is presented: it consists of a 1 degree-of-freedom (dof) superstructure and a 3 dof macro-element foundation. Both the superstructure and the soil-foundation system exhibit a non-linear behaviour. In particular the superstructure is characterized by an elastic perfectly plastic behaviour, while the foundation macro-element encompasses the two sources of non-linearity that arise in the soil-foundation interface: a) the one due to the irreversible elastoplastic soil behaviour (material non-linearity) and b) the one due to possible foundation uplift (geometric non-linearity). The global model thus entails the following features: …


A Simplified Approach For The Evaluation Of Kinematic Pile Bending, Francesco Castelli, Valentina Lentini, Michele Maugeri May 2010

A Simplified Approach For The Evaluation Of Kinematic Pile Bending, Francesco Castelli, Valentina Lentini, Michele Maugeri

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

There are two sources of loading of the pile by the earthquake: “inertial” loading of the pile head caused by the lateral forces imposed on the superstructure, and “kinematic” loading along the length of the pile caused by the lateral soil movements developed during the earthquake. Seismic codes prescribe that piles have to be designed for soil deformations arising from the passage of seismic waves which impose curvatures and thereby lateral strains on the piles along their whole length. Accepting these lines, the new Italian seismic normative (NTC, 2008) specify that kinematic effects should be taken into account in the …


Centrifuge Tests And Simple Analyses For Seismic Soil-Structure Interaction, Shuji Tamura, Keisuke Adachi, Kohji Tokimatsu May 2010

Centrifuge Tests And Simple Analyses For Seismic Soil-Structure Interaction, Shuji Tamura, Keisuke Adachi, Kohji Tokimatsu

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Dynamic centrifuge tests were performed on a superstructure-footing model that was placed on a dry sand surface and subjected to two different input motions having peak accelerations of 60 cm/s2 and 249 cm/s2. Two simple analyses, equivalent linear analysis (SHAKE) and dynamic response of a structure using a sway-rocking model (SR-model) were performed. The following conclusions were drawn: (1) SHAKE and SR-model analyses can simulate the recorded response of the soil and superstructure. However, the shear wave velocity of the ground that can simulate the superstructure response by an SR-model for amax=249 cm/s2 is …


Designing Optimization For Some Eolian Power Unit Taking Into Account The Seismic Loads Influence, Dragos Vintila, Diana Tenea, Anton Chirica May 2010

Designing Optimization For Some Eolian Power Unit Taking Into Account The Seismic Loads Influence, Dragos Vintila, Diana Tenea, Anton Chirica

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In the eastern part of the Romanian territory there are wind intensity conditions for some big eolian power units. From lithological point of view, the mentioned area is characterized by a loessial stratum of 3 up to over 20m deep which covers green shale rocks. The paper presents the designing consideration discussed in order to obtain the most economical foundation option. The corresponding calculus conclusions about the soil-structure interactions in seismic conditions are also revealed.


Dynamic Soil Structure Interaction Analysis Of Pile Supported High Rise Structures, Pulikanti Sushma, Ramancharla Pradeep Kumar May 2010

Dynamic Soil Structure Interaction Analysis Of Pile Supported High Rise Structures, Pulikanti Sushma, Ramancharla Pradeep Kumar

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Experiences from past earthquake disasters clearly shows that the ground motion was responsible for majority of property and life loss. Among the collapsed structures during the 1964 Niigata earthquake, the 1995 Kobe earthquake, the 1999 Koceli earthquake, the 2001 Bhuj earthquake and the 2004 Sumatra earthquake, excessive damage was occurred to pile supported bridges, towers, chimneys, high rise structures, etc. In view of this there is a need to study the complex behavior of soil-pile-structure interaction problems using numerical methods. In this research paper, a numerical study is carried out to understand the dynamic soil structure interaction of a high …


Dynamic Winkler Modulus For Axially Loaded End-Bearing Piles, George M. Anoyatis, George E. Mylonakis May 2010

Dynamic Winkler Modulus For Axially Loaded End-Bearing Piles, George M. Anoyatis, George E. Mylonakis

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The problem of dynamic pile-soil interaction and its modeling through the concept of a Dynamic Winkler Foundation are revisited. It is shown that depth-dependent Winkler springs and dashpots, obtained by dividing the complex-valued soil shear tractions and the corresponding displacements along the pile, may faithfully describe pile-soil interaction, contrary to common perception that the Winkler model is always approximate. A theoretical wave model is then derived for analyzing the response of axially loaded endbearing piles embedded in a homogeneous viscoelastic soil medium. Closed-form solutions are obtained for: (i) the displacement field in the soil and along the pile; (ii) the …


Effect Of Uplift Modelling On The Seismic Response Of Shallow Foundations, Liam Wotherspoon, Michael Pender May 2010

Effect Of Uplift Modelling On The Seismic Response Of Shallow Foundations, Liam Wotherspoon, Michael Pender

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper presents the development and response of a numerical model for the representation of uplift and reattachment of shallow foundations using the Ruaumoko non-linear dynamic analysis software. Vertical loads carried by the foundation were used to control the rotational and horizontal characteristics, as the stiffness of all degrees of freedom must reduce as the footing progressively detaches from the underlying soil. This culminates in the representation of total uplift, where the foundation provides no stiffness in any degree of freedom until vertical loads become compressive again. Through extension of the capabilities of Ruaumoko, this response was able to be …


Estimation Of Lateral Load Capacity Of Short Piles Under Earthquake Force, Indrajit Chowdhury, Shambhu P. Dasgupta May 2010

Estimation Of Lateral Load Capacity Of Short Piles Under Earthquake Force, Indrajit Chowdhury, Shambhu P. Dasgupta

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Lateral load induced in piles (both long and short) under earthquake is a problem of serious complexity that has been plaguing professional engineers and researchers alike for quite some time. The practice in vogue is to ensure that fixed base shear of the column does not exceed static shear load capacity of the piles. Inertial and stiffness effects of pile are usually ignored in dynamic earthquake analysis. The present paper proposes a method where, based on modal response or time history analysis, load on short piles may be estimated under earthquake considering its stiffness, inertia, effect of material and geometric …


Effects Of Soil-Structure Interaction On Stress Distribution Within A Pile Group Under Multi-Dimensional Loading, Hiroko Suzuki, Kohji Tokimatsu May 2010

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 …


Influence Of Soil-Structure Interaction On Seismic Response Of Shear Buildings, Stefano Renzi, George Mylonakis, Giovanni Vannucchi, Claudia Madiai May 2010

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 …


Interaction Between Superstructure And Substructure In Railways, Konstantinos Giannakos May 2010

Interaction Between Superstructure And Substructure In Railways, Konstantinos Giannakos

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The railway track superstructure undertakes the forces that develop during train movement and distributes them towards its seating. The track panel (sleepers with their fastenings or slab with the fastenings) plays a key role in terms of load distribution, while at the same time it ensures the stability of the geometrical distance between the rails. Earthworks and ballast (if it exists) undergo residual deformations, settlements and lateral displacements, directly influencing the deterioration of the so-called geometry of the track, which can be nevertheless described much more specifically as quality of the track. In this paper, a parametric investigation of the …


Nonlinear Soil-Pile Interaction Under Vertical And Coupled Motion, Bappaditya Manna, Dilip Kumar Baidya May 2010

Nonlinear Soil-Pile Interaction Under Vertical And Coupled Motion, Bappaditya Manna, Dilip Kumar Baidya

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper presents the test results of single (L/d = 15) and 2 x 2 group piles (L/d = 15 and s/d = 2, 3, 4) subjected to strong vertical and coupled vibration. The observed response curves display marked nonlinearity as the natural frequencies decreases with increasing intensity of excitation. The measured response is compared with the results obtained by using the continuum approach of Novak with dynamic interaction factor. To account for the nonlinear response of the piles, provisions are made for yielding of soil around the piles by introducing the weak boundary zone effect concept in the model. …


Numerical Analysis Of Disconnected Spread Footing On Soft Soil During Strong Earthquake, Sascha Richter, Roberto O. Cudmani May 2010

Numerical Analysis Of Disconnected Spread Footing On Soft Soil During Strong Earthquake, Sascha Richter, Roberto O. Cudmani

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

For the design of the Golden Ears approach bridge in Vancouver (Canada) a disconnected spread footing (DSF) was considered as alternative to a conventional pile foundation. In a DSF, a spread footing rests on natural ground improved by piles. Footing and piles are separated by a layer of coarse grained material. The mechanisms governing the behavior of the DSF during strong earthquake events have been investigated in a numerical finite element (FE) analysis using a (visco-)hypoplastic constitutive relationship. The FE model consists of a soil column (height 45 m) which includes the concrete piles. The superstructure is represented by a …


Pile-In-Tube Foundations With Reserve Switch-Off Elements And Other Systems For Seismic Response Adaptive Control, J. M. Eisenberg May 2010

Pile-In-Tube Foundations With Reserve Switch-Off Elements And Other Systems For Seismic Response Adaptive Control, J. M. Eisenberg

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Predominant ground motion frequencies and spectra could differ sufficiently at different earthquakes on one site. The reasons of the differences are the epicenter distance, the focal depth, and many others. As it is well known, the frequency spectral configuration and predominant frequency values influence the structural seismic response and seismic behavior of structures (Mexico earthquakes 1957, 1962; Bucharest, 1977, Spitak, Armenia, 1988 and other). The maximum seismic response depends of how close the fundamental frequency values of the structure are to the predominant ground motion frequencies. Seismoisolation as an effective approach to seismic response control became popular recent decades in …


Seismic Analysis Of Pile Group Using Pseudostatic Approach, H. Elahi, M. Moradi, H. G. Poulos, A. Ghalandarzadeh May 2010

Seismic Analysis Of Pile Group Using Pseudostatic Approach, H. Elahi, M. Moradi, H. G. Poulos, A. Ghalandarzadeh

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper evaluates a simple approximate pseudostatic method for estimating the maximum internal forces and horizontal displacements of pile group subjected to lateral seismic excitation. The method involves two main steps. At first the free-field soil movements caused by the earthquake are computed. Then the response of the pile group based on the maximum free-field soil movements which considered as static movements as well as a static loading at the pile head, which depends on the computed spectral acceleration of the structure being supported is analyzed. The methodology takes into account the effects of group interaction and soil yielding at …


Seismic Response Of Barrage Raft Floor Under Heterogeneous Soil Medium, Kumar Venkatesh, A. D. Pandey, N. K. Samadhiya May 2010

Seismic Response Of Barrage Raft Floor Under Heterogeneous Soil Medium, Kumar Venkatesh, A. D. Pandey, N. K. Samadhiya

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Seismic analyses of a barrage raft floor resting on homogeneous and heterogeneous subsoil condition were carried out by means of finite element modeling and analysis. Three dimensional models considering soil-raft-structure system were developed for both circumstances. The soil continuum, cut-off, pier, beam and abutment were modeled using eight noded brick element whereas raft floor was modeled using four noded plate bending element. The relevant amount of soil around and bottom of the barrage raft foundation has been modeled to find the effect of homogeneous and heterogeneous soil media on the seismic behavior of barrage raft floor. The seismic analysis was …