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Articles 2641 - 2670 of 7869

Full-Text Articles in Civil and Environmental Engineering

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 …

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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, …

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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 …

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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 …

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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 …

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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: …

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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 …

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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 …

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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.

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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 …

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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. …

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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 …

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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 …

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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 …

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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 …

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Seismic Response Of Inelastic Pile Foundations: A New Performance Based Design Philosophy, Nikos Gerolymos, Vassilis Drosos, George Gazetas May 2010

Seismic Response Of Inelastic Pile Foundations: A New Performance Based Design Philosophy, Nikos Gerolymos, Vassilis Drosos, George Gazetas

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

While seismic codes do not allow plastic deformation of piles, the Kobe earthquake has shown that limited structural yielding and cracking of piles may not be always detrimental. This paper focuses on the influence of soil compliance, pile-to-pile interaction, intensity of seismic excitation, pile diameter, above–ground height of the pile, location of plastic hinges (above or below ground development), on the seismic response of pile supported bridge structures. Evaluation of the bridge pier behaviour is achieved through key performance measure indices, as is: the displacement (global) and curvature (local) ductility demands and the maximum drift ratio. It is shown that …

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Soil-Structure Interaction Analysis For Bridge Caisson Foundation, Zhao Cheng, Hubert Law, Yang Jiang May 2010

Soil-Structure Interaction Analysis For Bridge Caisson Foundation, Zhao Cheng, Hubert Law, Yang Jiang

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

In the practical seismic analysis for the project of South Park Bridge Replacement, the caisson foundations are modeled as Winkler springs in the global bridge model. The global bridge model is then excited by depth-varying ground motions acting along the height of the caisson. The foundation model would entail Winkler springs distributed over the surfaces of caisson to represent the soil continuum underlying the foundation and passive soil pressure acting on the sides. The soil springs are nonlinear for consideration of yielding of localized soil. In addition, gapping elements can also be implemented in series with the soil springs to …

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Structure-To-Soil-Structure Interaction Analysis: A Case Study, Lisa M. Anderson, Tarek Elkhoraibi May 2010

Structure-To-Soil-Structure Interaction Analysis: A Case Study, Lisa M. Anderson, Tarek Elkhoraibi

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

Current industry codes, such as ASCE 4-98 recommend consideration of Structure-to-Soil-Structure Interaction (SSSI) only when it is determined to have a significant effect on local results. In some cases, it is not computationally feasible, or too costly, to analyze an explicit model including a complex of all contributing structures. The significance of SSSI is dependent upon several variables, namely the characteristics of the soil, structures, and ground motion, as well as the spatial distance between structures. The SSSI effect is most significant for lighter structures adjacent to more massive structures that are founded on soil sites. The Hanford Waste Treatment …

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Times-History Finite Element Dynamic Analysis - Soil Nail Wall - San Manuel Casino - Highland, California, Pirooz Barar, Qing Liu May 2010

Times-History Finite Element Dynamic Analysis - Soil Nail Wall - San Manuel Casino - Highland, California, Pirooz Barar, Qing Liu

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

The site of the proposed Phase II Parking Facility at the San Manuel Resort Casino, Highland, California, is on a sloped terrain where there is a 35 ft. grade differential from the north to the south end of the planned structure. PB&A, Inc. was selected to design a 12,000 square foot Soil-Nailed wall with a maximum height of 37 ft. to protect the Parking Structure from the soil pressures resulting from sloping ground conditions at the site. The project site is located within 100 feet of the San Andreas Fault in the highly seismic Southern California region, characterized by numerous …

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Wave-Induced Strength Weakening Of Soft Clay Below A Prefabricated Caisson Dike, Shuwang Yan, Jian Chu, Qijin Fan May 2010

Wave-Induced Strength Weakening Of Soft Clay Below A Prefabricated Caisson Dike, Shuwang Yan, Jian Chu, Qijin Fan

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

A case history of constructing offshore guide dikes on soft clay is presented in this paper. The guide dikes were constructed near the Shanghai Port, China, for deepening of navigation channel along the Yangtze Estuary. The guide dikes were designed as gravity retaining structures using prefabricated, semi-circular shaped concrete caissons. Some sections of the guide dikes were installed on a thick layer of soft soils. During the construction, the caissons in one section failed under a heavy storm. The causes of failure were investigated by running dynamic triaxial tests on undisturbed soil samples taken from the construction site, associated with …

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Soft Soil Effect On Soft Storey Response, Tahmeed M. Al-Hussaini, Kamruzzaman Khan May 2010

Soft Soil Effect On Soft Storey Response, Tahmeed M. Al-Hussaini, Kamruzzaman Khan

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

Multi-storied reinforced concrete frame (RCF) buildings with open first storey to provide parking space is common in Dhaka city, the capital of Bangladesh. Such buildings are likely to produce soft storey action when subjected to earthquake loadings. Bangladesh building code places Dhaka in a moderate earthquake zone with a zone coefficient (Z) value of 0.15. Several soft soil sites exist in the city, most of which have been created by filling up of low lands and water bodies without proper compaction. Such soft soil sites are likely to produce major site amplification effects during earthquakes. One-dimensional wave propagation using the …

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The Variable Damping Concept In Pile Capacity Prediction By Wave Equation Analysis, Mark R. Svinkin May 2010

The Variable Damping Concept In Pile Capacity Prediction By Wave Equation Analysis, Mark R. Svinkin

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

A wave equation method is applied for pre-driving analysis of driveability calculations and capacity prediction of driven piles. For the majority of piles, there are substantial differences between predicting results and pile capacities determined from static or dynamic tests. Correct calculations of the dynamic resistance are important for accurate prediction of the pile capacity. The dynamic resistance depends on the pile velocity and the damping coefficient, but both of them cannot reflect time-dependent changes of the pile-soil system after the end of driving. Variation of the pile-soil system after pile installation can be taken into account with a variable damping …

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A Review Of Seismic Lrfd (Load-And-Resistance Factor Design) Method For Mse (Mechanically Stabilized Earth) Walls, Fransiscus S. Hardianto, Kim M. Truong, John E. Sankey May 2010

A Review Of Seismic Lrfd (Load-And-Resistance Factor Design) Method For Mse (Mechanically Stabilized Earth) Walls, Fransiscus S. Hardianto, Kim M. Truong, John E. Sankey

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

The introduction of AASHTO’s LRFD (load-and-resistance factor design) method for the design of MSE (mechanically stabilized earth) walls in 2004 has gradually replaced conventional state-of-the-practice seismic ASD (allowable stress design) method in some states, and by FHWA mandate should completely replace the ASD method by 2010. Limit equilibrium analyses based on Mononabe- Okabe (M-O) pseudo-static method had been the standard method of estimating the seismic external thrust and inertia force for MSE walls. Considering the flexible nature of MSE walls that allow deformation without compromising structural integrity, in the LRFD method, the displacement based pseudo-static method that was developed from …

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Application Of Vertical Reinforcement For Performance Enhancement Of Reinforced Soil Under Seismic Loading, Binod Shrestha, Hadi Khabbaz May 2010

Application Of Vertical Reinforcement For Performance Enhancement Of Reinforced Soil Under Seismic Loading, Binod Shrestha, Hadi Khabbaz

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

Reinforced soils have been widely used in geotechnical structures as a result of their satisfactory performance and cost effectiveness. A number of investigations have been carried out to find out the seismic deformation modes of reinforced soil walls with conventional horizontal inclusions. This study puts forward a new concept of soil reinforcement, applying vertical reinforcement together with conventional horizontal reinforcement. A key difference between the general practice and after insertion of vertical reinforcement is that the latter not only provides passive resistance against shearing due to making intact layers but also increases the strength and stability of the reinforced soil. …

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