Application Of Vertical Reinforcement For Performance Enhancement Of Reinforced Soil Under Seismic Loading,
2010
University of Technology, Australia
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. …
Dynamic Response Of Cantilever Retaining Walls Considering Soil Non-Linearity,
2010
Politecnico di Torino, Italy
Dynamic Response Of Cantilever Retaining Walls Considering Soil Non-Linearity, Leuzzi Francesco, S. Foti, R. Lancellotta, G. Mylonakis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
For many decades the analysis of earth retaining structures under dynamic or seismic conditions has been carried out by means of standard limit equilibrium (Coulomb, M-O) or elastic methods (Wood, Veletsos and Younan). These approaches are simplified, as they make use of considerable approximations which are often applicable only under particular conditions. A different and perhaps more realistic approach is possible using established computer codes, which integrate numerically the governing equations of the soil and wall media. Since these problems may involve significant levels of strain in the backfill, material non-linearity should be taken into account to realistically simulate the …
Effects Of Internal Gas Explosion On An Underwater Tunnel Roof,
2010
University of Baghdad, Iraq
Effects Of Internal Gas Explosion On An Underwater Tunnel Roof, Omar Al-Farouk Salem Al-Damluji, Akram Younis Thannon Al-Sa'aty, Rafi' Mahmoud Sulaiman Al-Nu'aimy
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An underwater reinforced concrete tunnel roof is subjected to an internal gas explosion. Dynamic analyses are performed for three cases, namely, (1) an uncoupled solution, (2) class II coupling analysis and (3) full model with class I and II couplings. Three load cases are considered, dead (gravity) load, uniformly distributed vertical loads from sand and water and finally an internal pressure gas explosion. Linear and non-linear constitutive relationships are considered for the materials constituting the gas explosion problem. Results include time deflection of tunnel roof, time histories of stresses in vertical reinforcing bars and contours of concrete stresses for tunnel …
Numerical Simulation Of The Performance Of Cantilever Walls Subjected To Seismic Loading,
2010
Politecnico di Torino, Italy
Numerical Simulation Of The Performance Of Cantilever Walls Subjected To Seismic Loading, Alberto Pettiti, Dominic Assimaki, Sebastiano Foti
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The design of flexible earth retaining structures against seismic loading is a challenging geotechnical problem, and it is typically conducted using pseudo-static approaches, which do not adequately represent the transient loading conditions of earthquake motions. Numerical analyses of designed walls with simplified material models showed high stresses in the structure when subjected to both dynamic and pseudo-static conditions, and a very large amount of reinforcement would be required to avoid the formation of plastic hinges. On the other hand, detailed simulations with inelastic material behaviour would yield more realistic estimations of the retaining structural response and improve the efficiency of …
Seismic Analysis And Fragility Curves Of Gravity Waterfront Structures,
2010
Aristotle University of Thessaloniki, Greece
Seismic Analysis And Fragility Curves Of Gravity Waterfront Structures, Kalliopi Kakderi, Kyriazis Pitilakis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The aim of the study is to propose adequate fragility curves for waterfront/ retaining structures for ground shaking without the presence of liquefaction, using available data from past earthquakes’ damages in Europe and worldwide and numerical analysis of typical cases. Existing fragility curves and damage states are evaluated and their shortcomings and/or limitations are assessed. Typical waterfront structures, with different geometry, foundation soil conditions and seismic excitations, are studied using appropriate numerical modeling. The corresponding damage levels are estimated with respect to the induced residual displacements and the seismic response of the soil-structure system. Considering aleatory uncertainties of the parameters …
Seismic Analysis Of Retaining Wall Structures,
2010
University of Science and Culture, Iran
Seismic Analysis Of Retaining Wall Structures, Mohammadreza Abbasi Garavand, Alireza Saberi, Mona Salimi Ghezelbash
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper describes 3-D finite element dynamic analysis of retaining wall structures with consideration of the soil-structure interaction. Purpose of this study is to reduce damages due to earthquake in such structures. For this reason, finite element program ANSYS has been used. The analysis data is based on 1995 Kobe earthquake report and the results have been verified with some retaining walls were damaged in that earthquake. To take into account the non-linearity of soil-structure surface, surface to surface contact element is used. One of the most important problems in dynamic analysis is modeling of infinite media. If hinge or …
Seismic Lateral Earth Pressures On Retaining Structures,
2010
Indian Institute of Technology Guwahati, India
Seismic Lateral Earth Pressures On Retaining Structures, A. Murali Krishna
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Various methods are available to estimate seismic earth pressures on soil retaining structures which cane be grouped to experimental, analytical and numerical methods. 1G model shaking table studies or high-g level centrifuge model shaking studies give some insight on the variation of seismic earth pressures along height of the retaining structure. In the simple analytical methods, M-O method based pseudo-static analysis is extensively used to evaluate seismic earth pressure variation and its probable resultant location. Pseudodynamic analysis method based analyses are also developed and are in progress for the same. Besides, these experimental and analytical methods, FEM or FDM based …
Seismic Response Of Reinforced Soil Retaining Walls With Block Facings,
2010
Marian Engineering College, India
Seismic Response Of Reinforced Soil Retaining Walls With Block Facings, Anitha Nelson, P. K. Jayasree
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Reinforced soil walls have become very popular in seismic areas owing to their flexible nature and cost effectiveness when compared to the conventional retaining structures. Although the use of reinforced soil walls with modular block facings and gabion facings is growing world wide at a rapid rate, the seismic response of these walls is yet to be analyzed. This paper discusses the response of these walls in terms of lateral facing deflection, reinforcement tensile force and crest surface settlement when subjected to seismic loading simulated by means of a variable amplitude harmonic vibration using the finite element analysis package, PLAXIS …
An Alternative Method For Probabilistic Seismic-Hazard Assessment: A Case Study Of Three Cities,
2010
University of Hong Kong, Hong Kong
An Alternative Method For Probabilistic Seismic-Hazard Assessment: A Case Study Of Three Cities, Hing-Ho Tsang, Saman Yaghmaei-Sabegh, P. Anbazhagan, M. Neaz Sheikh, T. G. Sitharam, J. S. Vinod
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The conventional source-based method of probabilistic seismic-hazard assessment is considered difficult to conduct for regions lacking adequate information on the source characteristics, or with a paucity of recorded strong ground motion data. Meanwhile, the historic method is unreliable in estimating the hazard at low probability. This paper proposes a midway approach, derived from the source-based method, yet does not require the characterization of seismic sources. While the method possesses the simplicity of the historic method, it is extended to account for large events that have not been observed historically, in order to improve the reliability of hazard calculation at low …
Comparison Of Liquefaction Potential Evaluation Based On Different Field Tests,
2010
M.M.M. Engineering College, India
Comparison Of Liquefaction Potential Evaluation Based On Different Field Tests, Syed M. Ali Jawaid
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The lowlands of India are vulnerable to possible future large earthquakes. The liquefaction strength is estimated using in-situ tests and the factor of safety against liquefaction by comparing the liquefaction strength with cyclic shear stress ratio developed in the deposit during an earthquake. Standard Penetration test (SPT) and Cone Penetration test(CPT) have been most commonly used in-situ tests for characterization of liquefaction resistance. In this study, liquefaction potential is evaluated based on SPT as well as CPT data obtained from the three different locations situated in alluvial lowlands. A large difference in factor of safety against liquefaction is found based …
Characterization Of The Elastic Displacement Demand: Case Study - Sofia City,
2010
Central Laboratory Seismic Mechanics and Earthquake Engineering (CLSMEE), Bulgarian Academy of Sciences (BAS), Bulgaria
Characterization Of The Elastic Displacement Demand: Case Study - Sofia City, Ivanka Paskaleva, Mihaela Kouteva, Franco Vaccari, Giuliano F. Panza
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The results of the study on the seismic site response of a part of the metropolitan Sofia are discussed. The neo-deterministic seismic hazard assessment procedure has been used to compute realistic synthetic waveforms considering four earthquake scenarios, with magnitudes M=3.7, M=6.3 and M = 7.0. Source and site specific ground motion time histories are computed along three selected cross sections, making use of the hybrid approach, combining the modal summation technique and the finite differences scheme. Displacement and acceleration response spectra are considered. These results are validated against the design elastic displacement response spectra and displacement demand, recommended in Eurocode …
Evaluating Seismicity Parameters Of Sanandaj, Iran Based On Instrumental Earthquakes,
2010
University of Kurdistan, Iran
Evaluating Seismicity Parameters Of Sanandaj, Iran Based On Instrumental Earthquakes, Kaveh Andisheh, Gholamreza Ghodrati Amiri, Motaza Taghizadeh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The main goal of this paper is to evaluate the seismic parameters of Sanandaj, Iran. For this reason, at first, all the occurred instrumental earthquakes (1900-2006) in a radius of 200 km of Sanandaj city have been gathered. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters by Gutenberg-Richter method, cumulative distribution functions, and Kijko-Sellevoll approach. This paper aims at estimation of seismicity parameters based on the seismic events and the relation between the cumulative frequency of earthquake occurrence and its magnitude. For this purpose the variable windows in time …
Geotechnical And Seismic Risk Evaluation In Urban Areas,
2010
University of Catania, Italy
Geotechnical And Seismic Risk Evaluation In Urban Areas, Piera Paola Capilleri, Michele Maugeri, Erminia Raciti
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic and geotechnical hazard problems are widespread all over the world and they can cause natural disasters, damaging properties or causing human lives losses. Italian municipalities are not yet organised either to deal with the phenomena consequences, or to plan risk mitigation actions. A clear knowledge of the location and of the space and time evolution of the phenomena is needed for a vulnerability mitigation in the probably involved areas. Geo-hazard can be related with the consequences for exposed people and man made work by a microzonation. GIS technologies could play a crucial role in analysing large areas, but a …
Preparation The Site Specific Spectrum For Civil Regions Of Zagross Mountains,
2010
University of Kurdistan, Iran
Preparation The Site Specific Spectrum For Civil Regions Of Zagross Mountains, Kaveh Andisheh, Seydeh Sara Hossini, Mortaza Taghizadeh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper the site specific spectra for a region of the Zagros Mountains containing 5 cities in Kurdistan province of Iran is prepared. For this purpose, all the occurred earthquakes, containing both historical and instrumental events, in each 5 city have been gathered then main earthquakes was prepared by elimination the aftershocks, foreshocks, and the incorrect reported events from the data and main earthquakes were taken into consideration to calculate the seismic parameters by Kijko [2000] method considering uncertainty in magnitude and incomplete earthquake catalogue. All seismic sources of the region are modeled and recurrence relationship is established. After …
Uniform Seismic Hazard Spectra Of Sanandaj, Iran,
2010
University of Kurdistan, Iran
Uniform Seismic Hazard Spectra Of Sanandaj, Iran, Kaveh Andisheh, Gholamreza Ghodrati Amiri, Seyed Ali Razavian Amrei
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents uniform seismic hazard spectra of Sanandaj city of Iran. Sanandaj is the administrative center of Kurdistan province, in which more than 500,000 people live in. A collected catalogue, containing both historical and instrumental events and covering the period from the 10th century BC to the year 2006, is used. Then seismic sources and The seismotectonic model of the considered region have been modeled within the radius of 200 km and recurrence relationship is established. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters. For this purpose the …
Seismic Microzonation Of The Texcoco Lake Area, Mexico,
2010
Instituto de Ingeniería, UNAM, Mexico
Seismic Microzonation Of The Texcoco Lake Area, Mexico, Luis Osorio Flores, Juan M. Mayoral Villa, Miguel P. Romo
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents some of the most relevant results obtained from field, laboratory and analytical investigations aimed at characterizing the seismic environment prevailing at the Texcoco lake region, in the Valley of Mexico, with the goal of developing a microzonation. In particular, this study focuses on an area of 19.0 by 5.5 km2, which has been instrumented with four seismological stations: TXSO, TXS1, TXS2 and TXCH that have recorded ground motions for at least 15 years. Field investigations were conducted to define the subsoil conditions underneath each station. Dynamic testing in these high plasticity clays was carried out to establish …
Geotechnical Preconditions For Skyscrapers Construction In Bulgaria And Seismic Risk Aspect,
2010
University of Transport, Bulgaria
Geotechnical Preconditions For Skyscrapers Construction In Bulgaria And Seismic Risk Aspect, Chavdar V. Kolev, Martina G. Perikliyska
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Parallel to the economic development of Bulgaria in the last nine – ten years there is a rapid raise in construction as well. This increase has been a good precondition for invest in some very high buildings with application of the newest technological achievements. These buildings are situated in the centrums of the largest Bulgarian cities: Sofia, Plovdiv, Varna and Bourgas. The Paper describes the geotechnical preconditions for construction of this type of buildings from seismic risk aspect. These preconditions are divided in four groups: geological, urban, technological and economical. The paper renders an account of the preconditions which are …
Application Of High-Power Electrical Sparks For Dynamic Compaction Of Soil,
2010
Gersevanov Research Institute of Foundations and Underground Structures, Russia
Application Of High-Power Electrical Sparks For Dynamic Compaction Of Soil, Kh. A. Dzhantimirov, S. A. Rytov, S. A. Kryuchkov
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The paper describes an electrical discharge technology, applied for soil compaction around a borehole, filled with hardening grout, in operations for erection of micropiles, cast piles, soil anchors and soil nails. The technology consists in that 150-250 microsecond long electrical sparks are generated with 6-second period in borehole. The sparks have 30-40 kJ energy, which is roughly of the same order of magnitude as a pile drop hammer. But a single electrical spark has 200-250 MW because of its short duration. Such pulses compact the contact layer of soil and thus increase bearing capacity of piles, anchors or soil nails …
Floatation Of Tunnel In Liquefiable Soil,
2010
University of Cambridge, U. K.
Floatation Of Tunnel In Liquefiable Soil, S. C. Chian, S. P. G. Madabhushi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Underground structures such as tunnels have a lower unit weight than the surrounding soil and are commonly deemed to be susceptible to floatation in liquefiable soil. In the process of floatation, the tunnel has to possess ample buoyancy force to shear and carry the overlying soil upwards. This is aided by soil liquefaction resulting from the increase in water pressure with number of earthquake loading cycles. With onset of liquefaction, effective stress decreases which lead to a reduction in the shear strength of soil, hence assisting the floatation of tunnel. Conversely, the total stress exerted by the overburden soil suppresses …
Ground Motion Study On Dumbarton Toll Bridge,
2010
Earth Mechanics, Inc., Oakland, CA
Ground Motion Study On Dumbarton Toll Bridge, Te-Chih Ke, Hubert Law, Po Lam, Brian Maroney, Saba Mohan, Jason Weinstein
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The existing Dumbarton Toll Bridge was built in 1982, connecting the cities of Newark and East Palo Alto in the San Francisco Bay Area. The initial vulnerability studies conducted by California Department of Transportation (Caltrans) in 2004 indicated that the performance of the bridge during a maximum credible earthquake was uncertain. Earth Mechanics, Inc. (EMI) has carried out the necessary study for the seismic evaluation of the bridge. An extensive field investigation was undertaken both on-land and over-water at the site to develop the idealized subsurface profile along the bridge alignment. According to the probabilistic and deterministic seismic hazard analyses …
