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 …
Seismic Soil Pressures On Rigid Walls With Sloped Backfills,
2010
BC Hydro, Canada
Seismic Soil Pressures On Rigid Walls With Sloped Backfills, Guoxi Wu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Wood (1973) provided analytical solutions for the response of a rigid wall retaining elastic uniform soil backfill of finite length subjected to harmonic base excitation. Wu and Finn (1999) proposed a modified shear beam solution and derived closed-form formulations for computing dynamic soil pressures under harmonic loading. However, for rigid walls retaining sloped backfills, analytical solutions are not available for computing seismic soil pressures against the walls. In the current study, seismic soil pressures on rigid walls retaining 2H:1V (27°) sloped backfills have been computed using a total of eight acceleration time histories recorded in past large earthquakes. These records …
An Upgrade Of The Microzonation Study Of The Centre Of Tirana City,
2010
Polytechnic University of Tirana, Albania
An Upgrade Of The Microzonation Study Of The Centre Of Tirana City, Llambro Duni, Luljeta Bozo, Neki Kuka, Enkela Begu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An attempt was made in this paper to present an upgrade of the seismic microzonation of a part of the Tirana City. Some results of the previous, complete study performed in the late 80-s were used in this paper. The new aspect of this study is related to the probabilistic assessment of the ground motion parameters. Using gridded seismicity methodology, the PGA and the uniform response spectrum at the base rock corresponding to the 475-years return period were estimated. Based on them, five acceleration time histories are selected, which are later used to assess the response of the geotechnical models …
Analysis Of Earthquake Site Response And Site Classification For Seismic Design Practices,
2010
Suramericana S.A., Colombia
Analysis Of Earthquake Site Response And Site Classification For Seismic Design Practices, Gloria M. Estrada
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In general, seismic provisions worldwide present different criteria for site classification, based on specific soil and rock properties, in order to determine representative design spectra for seismic design. On the other hand, results of site–specific analysis and seismic microzonation studies have shown not only the main properties of soil-rock profile that have marked influence on site response, but also site characteristics where it is necessary to carry out detailed and particular studies of earthquake ground response. This paper analyzes and compares site classification for seismic design of some seismic codes worldwide, with results of site-specific analysis and seismic microzonation studies. …
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 …
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 …
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 …
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 …
The Meaning Of Eurocode 8 And Induced Seismicity For Earthquake Engineering In The Netherlands,
2010
Volker Wessels Stevin Geotechniek, The Netherlands
The Meaning Of Eurocode 8 And Induced Seismicity For Earthquake Engineering In The Netherlands, J. W. R. Brouwer, T. Van Eck, F. H. Goutbeek, A. C. W. M. Vrouwenvelder
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The Netherlands is one of the few European countries where seismic loading is not a dominant part of the national codes. Only for very special structures, earthquakes are regarded as a separate loading case. Until now, Eurocode 8 (EC8) is not part of Dutch building laws nor is there an official Dutch translation. Tectonic seismicity mainly occurs in the southern part of The Netherlands. The Dutch code NEN 6702 has a zonation map which shows horizontal peak accelerations of 0.01g to 0.1g for a return period of 5000 years. However, this seismic zonation map is yet not coherent with 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 …
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 …
The Influence Of Irregularity On The Values Of Demand Modifier Factor In Asce 41-06,
2010
Building and Housing Research Center, Iran
The Influence Of Irregularity On The Values Of Demand Modifier Factor In Asce 41-06, M. R. Malek Mohammad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In the past two decades, many investigations have been made on the methods related to the seismic retrofitting of the structures. As the real nonlinear behaviors of the elements are considered in these methods, the values of internal forces determined in the members are equal to the real ones. In the structural seismic linear analysis methods the elements behaviors are still assumed linear. In this regard, the passage of structure through yield point borders and the displacement increasing are correspondent to the forces elevation. In FEMA codes, the factors such as demand modifier (m) or increasing capacity ones are presented …
Comparison Of Erosional Features By Tsunami And Wind Waves,
2010
National Institute of Technology, India
Comparison Of Erosional Features By Tsunami And Wind Waves, B. K. Pal, M. K. Panda
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The erosion features from tsunami wave and wind wave are different according to the characteristics of the two kinds of waves. The tsunami wave is a shallow water wave, even in Deep Ocean, with very long wavelength and relatively high especially near shore. It does not break when attacking the shore. It composed of run-up and run-down. The waves which can scour the offshore sea bottom and deposit the sediment mostly sand on the coast called storm or tsunami over washes. The erosion features from storm wave are caused by the breaking waves and wind-driven currents. However, the erosion features …
Vibro Replacement And Soil Mixing Ground Improvements At A Shopping Mall Site In San Diego, California, Usa,
2010
Hayward Baker Inc., Santa Paula, CA
Vibro Replacement And Soil Mixing Ground Improvements At A Shopping Mall Site In San Diego, California, Usa, Lisheng Shao, Jack Kinley
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A 230,000 ft2 (21,367 m2) addition was planned for construction at the Plaza Bonita shopping mall in San Diego, CA. The soil profile at the site consisted of fill soils underlain by alluvial deposits followed by San Diego Formation. The saturated loose sand layers were liquefiable and would result in significant settlement under the site design earthquake. In addition, soft clay layers would undergo excessive settlement under heavy building column loads. The geotechnical contractor proposed soil treatment with vibro replacement stone columns to mitigate the site liquefaction and to reduce static settlement under building column loads. Building …
Assessment Of Rock Pressure For Tunnels In The Himalayan Region — A Case History,
2010
Sagar Royal Homes, India
Assessment Of Rock Pressure For Tunnels In The Himalayan Region — A Case History, A. K. Dube
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Since early sixties numerous tunnels had been planned and constructed for hydro-electric power generation in the Himalayan Region of India. The mountain chain is of very recent origin geologically and is believed to be still active tectonically. The geology is complex and tunneling under such circumstances had been a real challenge. It was a tough task to predict the geotechnical behaviour of the tunneling media. Beginning with the classical approach of Terzaghi (1925-46) many rock pressure estimation theories had been evolved for prediction and estimation of rock pressure for designing competent and stable tunnel supports. The author has made an …
Experimental Investigation Of Plastic Demands On Piles During Lateral Spread-Induced Loads,
2010
University of California San Diego, La Jolla, CA
Experimental Investigation Of Plastic Demands On Piles During Lateral Spread-Induced Loads, Barbara J. Chang, Tara C. Hutchinson
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Past earthquakes have demonstrated that lateral spreading from liquefaction of the soil may cause undesirable movement and potential failure to the below ground portion of a pile foundation. For a multi-layer soil profile, the case of a dense crust layer overlying a liquefiable soil layer may create large localized plastic demands in the piles. To study this behavior and provide detailed data for use in model validation studies, a one-g shaking table experiment was conducted considering a single reinforced concrete pile embedded in a 3-layer soil system. The model pile of 10 inch diameter was tested in a sloped laminar …
Large-Scale Shake Table Test On Lateral Spreading Of A Sheet-Pile Wall Model And Its Centrifuge Simulation,
2010
National Research Institute for Earth Science and Disaster Prevention, Japan
Large-Scale Shake Table Test On Lateral Spreading Of A Sheet-Pile Wall Model And Its Centrifuge Simulation, Masayoshi Sato, Kentaro Tabata, Akio Abe
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this test was to realistically reproduce soil liquefaction and the lateral spreading of saturated sand deposits behind the sheet-pile quay walls and the consequent deformation and translation of neighboring pile foundations. Therefore, a shake table test was carried out using a large-scale laminar box on the large-scale shake table in Tsukuba. The inside dimensions of the model were 11.6 m in length, 3.1 m in width and 4.5 m in depth. Next, a dynamic centrifuge test on the behavior of a sheet-pile wall and a soil pile system was conducted to simulate that of a large-scale shake …
