Ground Improvement For Increasing Lateral Pile Group Resistance,
2010
Brigham Young University, Provo, UT
Ground Improvement For Increasing Lateral Pile Group Resistance, Kyle M. Rollins, Matthew E. Adsero, Mark A. Herbst, Nathan Lemme
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Lateral load tests were performed on a full-scale pile cap in untreated clay along with pile groups involving (a) excavation and replacement with sand backfill, (b) a soilcrete wall along the side of the pile group, and (c) a jet grouted zone below the pile cap. The average compressive strength of the soft, plastic clay increased from an average of 50 kPa to an average of about 1000 kPa with soil mixing (10% cement) and to 3000 kPa with jet grouting (20% cement). Excavation and replacement only increased resistance by about 20%; however, the soil mixed wall increased resistance by …
Liquefaction Induced Settlement Of Structures,
2010
University of Cambridge, U. K.
Liquefaction Induced Settlement Of Structures, Gopal S. P. Madabhushi, Stuart K. Haigh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Soil liquefaction following earthquakes leads to excessive damage to a wide variety of structures. Settlement and rotation of structures following liquefaction have been witnessed in many of the recent earthquakes. Investigation of the mechanisms of failure of structure when the foundation soil suffers either partial or full liquefaction is therefore very important. Dynamic centrifuge tests were conducted at Cambridge and elsewhere on different boundary value problems in which liquefaction of soil models was investigated. Excess pore pressure data and the settlement data for the particular structure that is being investigated are recorded during the centrifuge tests. In this paper the …
Liquefaction, Screening, And Remediation Of Silty Soils,
2010
University at Buffalo, SUNY Buffalo, NY
Liquefaction, Screening, And Remediation Of Silty Soils, S. Thevanayagam
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Assessing liquefaction potential, in situ screening, and remediation of non-plastic silty soils are difficult problems. Presence of silt particles among the sand grains in silty soils affects the soil response in each of the above cases in different ways. First part of this paper addresses the effects of silt content on liquefaction resistance, hydraulic conductivity, and coefficient of consolidation of silty soils compared to clean sand. Secondly it addresses the effects of silt content and consolidation characteristics on cone resistance of silty soils and sand. A relationship between normalized cone resistance, liquefaction resistance, and consolidation characteristics is presented. The third …
Principles And Practices Of Seismic Microzonation: Case Studies In India,
2010
Indian Institute of Science, India
Principles And Practices Of Seismic Microzonation: Case Studies In India, T. G. Sitharam, P. Anbazhagan, K. S. Vipin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents an overview of the principles and practices of seismic microzonation with some case studies in India. India has experienced major damages and loss of life due to earthquakes. Macrozonation map in Indian seismic code IS-1893 is frequently revised soon after a major earthquake in the country. New revision which was published in 2002 after Bhuj earthquake in 2001 contains four macro zones. These zones are based on geology and limited seismology input without considering geotechnical aspects such as site effects and liquefaction. In order to understand the earthquake vulnerability of major urban centers and prepare new zonation …
Recent Advances In Non-Linear Site Response Analysis,
2010
University of Illinois at Urbana-Champaign, Urbana, Illinois-USA 61801
Recent Advances In Non-Linear Site Response Analysis, Youssef M. A. Hashash, Camilo Phillips, David R. Groholski
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Studies of earthquakes over the last 50 years and the examination of dynamic soil behavior reveal that soil behavior is highly nonlinear and hysteretic even at small strains. Non-linear behavior of soils during a seismic event has a predominant role in current site response analysis. The pioneering work of H. B. Seed and I. M. Idriss during the late 1960’s introduced modern site response analysis techniques. Since then significant efforts have been made to more accurately represent the non-linear behavior of soils during earthquake loading. This paper reviews recent advances in the field of non-linear site response analysis with a …
Liquefaction-Induced Movements Of Buildings With Shallow Foundations,
2010
University of California Berkeley, Berkeley, CA
Liquefaction-Induced Movements Of Buildings With Shallow Foundations, Jonathan D. Bray, Shideh Dashti
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismically induced settlement of buildings with shallow foundations on liquefiable soils has resulted in significant damage in recent earthquakes. In Adapazari, Turkey multi-story buildings punched into, tilted excessively, and slid laterally on softened ground. The state-of-the-practice still largely involves estimating building settlement using empirical procedures developed to calculate postliquefaction consolidation settlement in the free-field. This approach cannot possibly capture shear-induced and localized volumetricinduced deformations in the soil underneath shallow mat foundations. Geotechnical centrifuge experiments were performed recently to identify the dominant mechanisms involved in liquefaction-induced building settlement. The centrifuge tests revealed that considerable building settlement occurs during earthquake strong shaking. …
Recent Advances In Seismic Design Of Geosynthetically-Lined Waste Containment Facilities,
2010
Geosyntec Consultants, Huntington Beach, CA
Recent Advances In Seismic Design Of Geosynthetically-Lined Waste Containment Facilities, Neven Matasovic
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Geosynthetic materials are essential elements of almost all modern landfill barrier systems. Materials such as geomembranes and geosynthetic clay liners are widely used as resistive barrier elements while geotextiles, drainage nets, and geocomposites are widely employed in modern composite barrier systems for both landfill liners and covers. The ability of these geosynthetic elements to maintain their integrity when subject to deformations due to waste settlement and seismic loading is a major uncertainty with respect to the performance of modern landfills. Over past years, advances have been made in understanding of material behavior under cyclic loading, modeling of modern landfill response …
Recent Advances In Terrestrial Lidar Applications In Geotechnical Earthquake Engineering,
2010
U.S. Geological Survey, Menlo Park, CA
Recent Advances In Terrestrial Lidar Applications In Geotechnical Earthquake Engineering, Roberto Kayer, Jonathan P. Stewart, Brian D. Collins
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During the past five years, geotechnical earthquake engineering and ground deformation research has benefited from the advent of terrestrial LIDAR technology, a revolutionary tool for characterizing fine-scale changes in topography. For ground deformation research, LIDAR is particularly useful for characterizing the dimensions of failures and for monitoring subtle deformations through time. Tripod mounted LIDAR systems have accuracies of approximately 0.4-2.0 cm, and can illuminate targets up to one kilometer away from the sensor. During several minutes of LIDAR scanning, millions of survey position points are collected and processed into an ultra-high resolution terrain model. During earthquake reconnaissance efforts, the detailed …
Zero-Gravity Triaxial Shear Tests On Mechanical Properties Of Liquefied Sand And Performance Assessment Of Mitigations Against Large Ground Deformation,
2010
University of Tokyo, Japan
Zero-Gravity Triaxial Shear Tests On Mechanical Properties Of Liquefied Sand And Performance Assessment Of Mitigations Against Large Ground Deformation, Ikuo Towhata, Trinh Thi Lan Anh, Suguru Yamada, Ramin Motamed, Yoshikazu Kobayashi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper concerns prediction of liquefaction-induced large deformation of geotechnical structures that will play major roles in practice of seismic performance design. To do this prediction, it is essential to establish a mechanical model for liquefied sand in which effective stress is null or extremely low. Although past model tests suggested that liquefied sand behaves similar to viscous liquid, there is an opinion against it that pore water pressure distribution in embedded structures produces an apparent rate-dependent behavior. This opinion was examined precisely and quantitatively by analyzing a full-scale model test to find that the pore pressure theory cannot account …
Geotechnical Aspects Of Recent Japan Earthquakes,
2010
Tokyo Denki University, Japan
Geotechnical Aspects Of Recent Japan Earthquakes, Susumu Yasuda, Tomohiro Tanaka
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Recently middle class earthquakes have occurred and caused various geotechnical damages every year in Japan. Among them geotechnical damages during five earthquakes from 2004 to 2008 are introduced. The 2004 Niigataken-chuetsu earthquake caused failure of expressway embankments and uplift of sewage manholes. Liquefaction-induced damage to quay walls and tanks occurred in artificially reclaimed lands during the 2005 Fukuokaken-seiho-oki earthquake. Liquefiable area had been predicted about 17 years before the earthquake. Liquefied zones were fairly coincided with the predicted liquefiable zones. Very severe slide of highway embankments occurred at 11 sites during the 2007 Notohanto earthquake. During the 2007 Niigataken-chuetsu-oki earthquake, …
Geotechnical Aspects Of Recent Pakistan Earthquakes,
2010
NUST Institute of Civil Engineering, Pakistan
Geotechnical Aspects Of Recent Pakistan Earthquakes, Sarfaraz Ali, Liaqat Ali, Muhammad Ammar
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Geologically, Kashmir and northwestern areas of Pakistan are located in most active seismic zones of sub-continent. In Kashmir area, earthquakes had been triggered by a continuous subduction phenomenon of Indian plate under Eurasian plate; a collision zone that created Himalaya Mountain range and still giving it a rise of 1 cm each year. The Quetta earthquake occurred on part of the left-lateral Chaman Fault System and was measured 8.1 on Richter scale with focal depth of 17 km. The earthquake completely devastated the city of Quetta, leaving 35000-60000 dead and injuring thousands of people in affected areas. The Kashmir earthquake …
Strong Ground Motion In The Epicentral Region Of The MW 6.3, Apr 6 2009, L’Aquila Earthquake, Italy,
2010
Politecnico di Milano, Italy
Strong Ground Motion In The Epicentral Region Of The MW 6.3, Apr 6 2009, L’Aquila Earthquake, Italy, Roberto Paolucci, Chiara Smerzini
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In the night of Apr 6 2009, a Mw 6.3 earthquake struck the Abruzzi region and the whole Central Italy, causing about 300 deaths and vast destructions in the town of L'Aquila, one of the largest urban centres in Central Italy, and its surroundings. As most destructive earthquakes in the Italian Central and Southern Apennines mountain chain, this was caused by a normal fault rupture, the epicenter of which was estimated at less than 5 km from the center of L'Aquila. Several 3-components digital strong motion instruments were installed around L'Aquila at few km distance from the epicenter: 3 …
The Non-Regularity Of Earthquake Recurrence In California: Lessons From Long Paleoseismic Records From The San Andreas And San Jacinto Faults In Southern California, And The North Anatolian Fault In Turkey,
2010
San Diego State University, San Diego, CA/ Earth Consultants International, Santa Ana, CA
The Non-Regularity Of Earthquake Recurrence In California: Lessons From Long Paleoseismic Records From The San Andreas And San Jacinto Faults In Southern California, And The North Anatolian Fault In Turkey, Thomas Rockwell
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A long paleoseismic record at Hog Lake on the central San Jacinto fault in southern California documents evidence for 18 surface ruptures in the past 3.8-4 ka. This yields a long-term recurrence interval of about 210 years, consistent with its slip rate of ~15 mm/yr and field observations of 3-3.5 m of displacement per event. However, during the past 3800 years, the fault has switched from a quasiperiodic mode of earthquake production, during which the recurrence interval is similar to the long-term average, to clustered behavior with the inter-event periods as short as a few decades (five surface ruptures occurred …
A Structural Engineer’S Approach To Efficient Sfsi: Towards Performance Based Design,
2010
The University of Western Ontario, Canada
A Structural Engineer’S Approach To Efficient Sfsi: Towards Performance Based Design, M. Hesham El Naggar
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Performance-based design (PBD) involves designing structures to achieve specified performance targets under specified levels of seismic hazard. This involves analyzing the entire soil-structure system and requires structural and geotechnical expertise. This paper is focused on soil-foundation-structure interaction (SFSI) in relation to PBD. A Beam-on-Nonlinear-Winkler- Foundation (BNWF) model is developed to incorporate important SFSI aspects into structural analysis software. The model accounts for: nonlinearity due to soil yield and/or footing uplift; cyclic degradation of stiffness and strength due to variable-amplitude loading; distribution of soil resistance underneath the footing for different loading conditions; reduction in radiation damping with increased nonlinearity; and coupling …
An Innovative Procedure For The Rapid Mapping Of Urban Earthquake Vulnerability,
2010
intraVidére Research Institute, Italy
An Innovative Procedure For The Rapid Mapping Of Urban Earthquake Vulnerability, Filippo Ciuffi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The present paper summarizes the original approach, the different stages, the innovative algorithms and the most interesting results of a new, “simplified procedure” for mapping Earthquake Vulnerability in urban areas. The devised procedure is based on the processing data generated by “Remote Sensing Techniques”, for the design and the construction of two different square matrixes: Building Vulnerability Matrix and Soil Vulnerability Matrix. Combination of mathematical classification procedures and matrix analysis techniques have been designed and implemented, for creating the “basic models” of the mentioned matrixes, together with the related algorithms, “ad hoc” devised. The classes and the groups generated within …
Corps Of Engineers Practice In The Evaluation Of Seismic Deformation Of Embankment Dams,
2010
U.S. Army Corps of Engineers, Sacramento, CA
Corps Of Engineers Practice In The Evaluation Of Seismic Deformation Of Embankment Dams, Vlad G. Perlea, Michael H. Beaty
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Guidance for the Corps of Engineers requires the use of seismic deformation analysis in the evaluation of existing dams for seismic loads and in the validation of remediation design for seismically deficient embankment dams. The Corps uses a phased approach for evaluating the seismic safety. For dams with significant seismic loads, problem soils, high risk, or those where simple analyses identified seismic concerns, a more advanced deformation analysis is generally required. A major challenge in these analyses is the selection of a reliable constitutive model when liquefiable materials are present. The computer program FLAC, in conjunction with a modified version …
Current Seismic Soil-Foundation-Structure Interaction State Of The Art And Practice On California Toll Bridge Program,
2010
Office of Earthquake Engineering, Caltrans, Sacramento, CA
Current Seismic Soil-Foundation-Structure Interaction State Of The Art And Practice On California Toll Bridge Program, Anoosh Shamsabadi, Hubert K. Law
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
California Department of Transportation (CALTRANS) initiated a seismic retrofit program in early 1990 following the Loma Prieta and Northridge Earthquakes to strengthen existing toll bridges and many regular bridges in California. Prior to the CALTRANS’ seismic retrofit program, there were very little guidelines and criteria available to undertake seismic retrofit of existing bridges and design of new structures to withstand potentially large magnitude future earthquakes. Significant advancements have been made since the beginning of the seismic retrofit program. This paper will discuss the author’s experience from the seismic retrofits of many existing toll bridges and designs of new toll bridges. …
The Importance Of Creating Value In Seismic Design,
2010
Arup, U.K.
The Importance Of Creating Value In Seismic Design, Barnali Ghosh, Zygmunt Lubkowski, Jack Pappin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Major earthquakes have resulted in devastating consequences in terms of human and economic loss. In almost all the earthquakes we observe the failure of structures, sometimes due to poor construction but also due to designers not identifying the specific geo-hazards (iIntensity of ground motion, faults, liquefaction, slopes etc) which affect these structures. In many cases these damages could have been avoided if the original design had correctly identified the geohazards at the site and incorporated the philosophy of performance based design. In this paper several examples will be presented where the different stages of risk assessment will be identified and …
Site Amplification Studies For Npp Sites In Switzerland Within The Project Pegasos And Prp,
2010
Studer Engineering, Switzerland
Site Amplification Studies For Npp Sites In Switzerland Within The Project Pegasos And Prp, Jost A. Studer
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Based on a request by ENSI (Nuclear Regulatory Authority of Switzerland) to update the existing probabilistic earthquake hazard studies, Swissnuclear, the association of the nuclear power plants in Switzerland, initiated the PEAGASOS Project. The project started in 2001 and finished in 2004. It is for Europe a unique study, which aimed to evaluate uncertainties systematically and comprehensively. It was decided to perform the study on SSHAC-level 4. Level 4, defined by the Senior Seismic Hazard-Committee, is the highest level and was used only once before for the Yucca-Mountain-Project in the USA. In the PEGASOS Project, 21 international experts from Europe …
Machine Foundations And Blast Engineering Vibrations Case Studies,
2010
Technical University of Civil Engineering Bucharest, Romania
Machine Foundations And Blast Engineering Vibrations Case Studies, Ion Vlad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Vibration can cause either serviceability and malfunctioning problems reducing people’s comfort to an unacceptable level, or safety problems with danger of failure. The belief of the author is that the presentation of some practical cases of machine foundation vibrations will be of interest, beneficial and helpful for many researchers and engineers involved in both theoretical and practical studies. Therefore, the most relevant case studies on vibrations of machine foundation ensembles, encountered in practice in the last ten years of activity, will be presented. In all malfunctioning or excessive vibration cases the technical assessment has started with a complex program of …
