Seismic Design and Risk Assessment of Underground Long Structures
Author: Kyriazis Pitilakis Sotiris Argyroudis and Grigoris Tsinidis | Size: 7.3 MB | Format:PDF | Quality:Unspecified | Publisher: Aristotle University | Year: march 2011 | pages: 124
• Conceptual, geometrical, and operational features of underground long structures, make their seismic behavior very distinct from aboveground structures
• Imposed seismic ground deformations rather than inertial forces dominate the structure’s seismic response
• Relative lack of well-documented case histories, lack of well validated methodologies and lack of specific guidelines and seismic code regulations for seismic design
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Author: Anand S. Arya | Size: 2.4 MB | Format:PDF | Quality:Unspecified | Publisher: Journal of South Asia Disaster Studies | Year: 2008 | pages: 21
As per the Census of India 2001, masonry housing units constitute 84.7% of the total 249 million housing units in India. Observations in all the past earthquakes in the country as well as in the other earthquake-prone SAARC countries have shown that masonry buildings are the most vulnerable to damage and collapse under earthquake Intensities MSK VII or more. Therefore, it has been realized that such existing buildings will need upgrading of seismic resistance by appropriate retrofitting techniques. The first step in this direction is proper seismic assessment to determine the weaknesses and deficiencies in such buildings which will require action to increase the strength and remove the deficiencies. This paper deals with this subject in two stages:
First, Method of Rapid Visual Screening which could be carried out by a site inspection and noting some crucial data about the building under consideration and its comparison with the damageability
observed through MSK/European Macro Intensity Scales would give the damage vulnerability level of the building. Second, a more detailed methodology is provided for carrying out the assessment of the building by comparing the actual construction details with the safe details recommended in IS:4326-1993. By this comparison, the weaknesses and deficiencies can be listed for improvement.
In some cases material testing, particularly that of the mortar quality, may have to be carried out for taking the final decision about the retrofitting methodology.
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Tunnels under seismic loading: a review of damage case histories and protection methods
Author: G. Lanzano+ , E. Bilotta, G. Russo | Size: 0.8 MB | Format:PDF | Quality:Unspecified | Publisher: Department of Hydraulic, Geotechnical and Environmental Engineering (DIGA). University of Naples Federico II, Italy and+ SAVA Department, University of Molise, Campobasso, Italy | pages: 10
Underground structures are essential in urban areas and their number is continuously increasing. Even if buried structures commonly show a better performance under seismic actions than above-ground structures, during recent strong earthquakes some urban underground structures suffered severe damages and collapses. In order to understand the behaviour of tunnels during earthquake, a wide collection of case histories has been reviewed from the available literature and some of them have been described in detail. Criteria are also shown in the paper which are used to classify the damage database. Such a classification involves entity and type of damage and is aimed to highlight the possible causes of damage, in order to improve performance-based seismic design of tunnels.
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EXTENDING THE COLLAPSE TIME OF NON-ENGINEERED MASONRY BUILDINGS UNDER SEISMIC LOADING
Author: J. Macabuag and S. Bhattacharya | Size: 3.1 MB | Format:PDF | Quality:Unspecified | Publisher: EWB-UK Research Conference 2009 Hosted by The Royal Academy of Engineering February 20 | Year: 2009 | pages: 14
THE COLLAPSE OF NON-ENGINEERED MASONRY IS ONE OF THE GREATEST CAUSES OF DEATH IN MAJOR EARTHQUAKE EVENTS AROUND THE WORLD. THIS PAPER INVESTIGATES A RECENTLY DEVELOPED RETROFITTING TECHNOLOGY SPECIFICALLY AIMED AT PREVENTING OR PROLONGING THE COLLAPSE OF ADOBE (MUD BRICK) BUILDINGS UNDER STRONG EARTHQUAKES.
THIS TECHNOLOGY USES COMMON POLYPROPYLENE PACKAGING STRAPS TO FORM A MESH, WHICH IS THEN USED TO PREVENT BRITTLE MASONRY COLLAPSE. THE RETROFITTING TECHNIQUE IS TESTED USING STATIC, DIAGONAL LOADING OF MODEL WALL PANELS. IT IS SHOWN THAT THE PROPOSED TECHNIQUE EFFECTIVELY PREVENTS BRITTLE COLLAPSE OF THE PANEL AND THE LOSS OF DEBRIS. PARTIAL MESHES OF VARIOUS ORIENTATIONS ARE ALSO INVESTIGATED IN ORDER TO BETTER IDENTIFY THE ACTION OF THE MESH. FINALLY, AN IMPLEMENTATION PROJECT IS PRESENTED, INVOLVING A TRAINING PROGRAMME FOR RURAL MASONS IN NEPAL AND A PUBLIC SHAKE-TABLE DEMONSTRATION.
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PEFORMANCE OF EXISTING REINFORCED CONCRETE COLUMNS UNDER BIDIRECTIONAL SHEAR AND AXIAL LOADING
Author: Laura M. Flores | Size: 1.07 MB | Format:PDF | Quality:Unspecified | Publisher: University of California, San Diego REU Institution: University of California, Berkeley REU Advisor: Professor Jack P. Moehle | pages: 42
Many existing reinforced concrete structures were designed before the introduction of modern seismic code and are thus vulnerable to collapse in the event of an earthquake. It is often more economically feasible to retrofit these structural components than to completely replace them. In order to strengthen these susceptible reinforced concrete structures against seismic loading, it is important to understand the progression of damage and mechanisms causing collapse in such structures under both gravity and seismic loads. Large-scale shake table testing and verification studies are currently being conducted at UC Berkeley-PEER to aid in the development of an OpenSees analytical model which will simulate and predict the hysteretic response of existing reinforced concrete structures in future verification studies.
The purpose of this study was to produce column hysteretic data used to calibrate the OpenSees analytical model. Empirical capacity models were used to predict the hysteretic response of shear-critical reinforced concrete columns under gravity and seismic loading; in particular, shear failure and axial load collapse of these columns were closely examined. Based on pre-seismic ACI code, a column cross sectional analysis was completed to determine the undamaged capacity of the column. A one-third scale model of the column was fabricated and an experimental setup allowing bi-directional loading (for simulation of seismic and gravity loads) was designed and constructed. Column specimens were then subjected to quasi-static testing and the measured column hysteretic response was compared to that predicted by empirical capacity models which form the basis of the OpenSees analytical model.
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Nonlinear seismic vulnerability evaluation of irregular steel buildings with cumulative damage indices
Author: Mohsen Gerami, Yahya Sharbati* and Abbas Sivandi-Pour | Size: 2.06 MB | Format:PDF | Quality:Unspecified | Publisher: Gerami et al. International Journal of Advanced Structural Engineering | Year: 2013 | pages: 15
Measuring structural damage during earthquakes has always been a challenging problem for earthquake engineers. Various damage indices are proposed with the objective of quantifying the structural damage in prototype and model structures subjected to seismic excitation. In this study, seismic vulnerability of irregular steel buildings is assessed in three dimensions considering effects of the panel zone, which has not been considered in recent studies of the field of seismic vulnerability. The buildings are modeled with different storeys and irregular plans.
Seismic performance of buildings was assessed in life-safety and collapse-prevention levels. Cumulative functions of damage indices are applied in the nonlinear dynamic analysis of buildings in the near-field ground motions. It is concluded that participation rates of deformation and energy in the damage of irregular buildings are 74.5% and 25.5%, respectively. Severe damage and collapse due to seismic dissipated energy occurred in the initial storeys of low-rise buildings and in the middle storeys of high-rise buildings.
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Posted by: freequo - 08-27-2013, 08:17 AM - Forum: Archive
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Article/eBook Full Name: Programming the Finite Element Method in Java and Android
Author(s): Bryan J. Macdonald
Edition: 1st
Publish Date: 2013
ISBN: 1908689188
Published By: Glasnevin Publishing
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SEISMIC ANALYSIS OF KNEE ELEMENTS FOR STEEL FRAMES
Author: DENIS EMIL CLEMENT | Size: 13.8 MB | Format:PDF | Quality:Unspecified | Publisher: UNIVERSITY OF OXFORD | Year: 2002 | pages: 243
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Nonlinear Static Pushover Analysis of a Shear Wall Building in Madinah
Author: M. Ajmal¥ ,M.K. Rahman¥ and M.H. Baluch¥ ¥ King Fahd University of Petroleum & Minerals Dhahran Saudi Arabia | Size: 1 MB | Format:PDF | Quality:Unspecified | Year: 2012 | pages: 37
1. Some large cities in the Eastern and Western Part of Saudi
Arabia are located close to fault zones. As the population
increases and new areas are developed, the seismic risk to
human life and infrastructure increases.
2. Most old structures aredesigned without considering
seismic effect. i.e. designed for gravity loads.
3. Recent seismic activity in Saudi Arabia have led to concern
about the safety of the existing reinforced concrete
buildings.
4. This research is planned as a joint collaboration between
King Fahd university of Petroleum and Minerals (KFUPM),
Saudi Arabia and Istanbul Technical University (ITU),
Turkey.
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