Structural Analysis of Selected Failures Caused by the 27 February 2010 Chile Tsunami

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 215-243 ◽  
Author(s):  
Ian Robertson ◽  
Gary Chock ◽  
Juan Morla
Keyword(s):  
Flow Velocity ◽  
Structural Performance ◽  
Structural Element ◽  
Local Flow ◽  
Inundation Depth ◽  
Hydrodynamic Loading ◽  
Tsunami Damage ◽  
Chile Earthquake ◽  
Chile Tsunami ◽  
Loading Estimates

Following the 2010 Chile earthquake and tsunami, the authors participated in the EERI reconnaissance team that traveled to Chile to document damage and structural performance. The authors focused on tsunami damage following the earthquake. A summary of tsunami damage to structures is given. Based on a series of well-defined structural element failures at sites where inundation depth was measured, the team was able to evaluate the hydrodynamic loading required to cause these failures and derive estimated lower bound flow velocity overland during the event. It was estimated that the velocity exceeded 3.2 m/s in Talcahuano harbor and 4.3 m/s in the coastal town of Dichato. When found in proximity to damaged buildings and other larger structures of interest, these simple structures can serve as “flow surrogate instruments” to estimate the local flow velocity. Failure analysis of these simple structures indicated that the hydrodynamic loading estimates provided by FEMA P646 may be unconservative.

scholarly journals ESTIMATION OF DAMAGED AREAS DUE TO THE 2010 CHILE EARTHQUAKE AND TSUNAMI USING SAR IMAGERY OF ALOS/PALSAR

2016 ◽  
Vol III-8 ◽  
pp. 35-42
Author(s):  
Pertiwi Jaya Ni Made ◽  
Fusanori Miura ◽  
A. Besse Rimba
Keyword(s):  
Large Scale ◽  
Aerial Photographs ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Tsunami Damage ◽  
Before And After ◽  
Chile Earthquake ◽  
Multi Temporal ◽  
Sar Imagery ◽  
Inundation Map

A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km<sup>2</sup>. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

Unsteady critical liquid sheet flows

2017 ◽  
Vol 821 ◽  
pp. 219-247 ◽  
Author(s):  
M. Girfoglio ◽  
F. De Rosa ◽  
G. Coppola ◽  
L. de Luca
Keyword(s):  
Flow Velocity ◽  
Weber Number ◽  
Liquid Sheet ◽  
Global Dynamics ◽  
Equivalent Stiffness ◽  
Supercritical Regime ◽  
Local Flow ◽  
System Perspective ◽  
Linear Approach ◽  
Small Disturbances

The unsteady global dynamics of a gravitational liquid sheet interacting with a one-sided adjacent air enclosure (commonly referred to as nappe oscillation configuration) is addressed under the assumptions of potential flow and the presence of surface tension effects. From a theoretical viewpoint the problem is challenging, because from previous literature it is known that the equation governing the evolution of small disturbances exhibits a singularity at the vertical station where the local flow velocity equals the capillary wave velocity (local critical condition), although the solution to the problem has not yet been found. The equation governing the local dynamics resembles one featuring the forced vibrations of a string of finite length, formulated in the reference frame moving with the flow velocity, and exhibits both slow and fast characteristic curves. From the global system perspective the nappe behaves as a driven damped spring–mass oscillator, where the inertial effects are linked to the liquid sheet mass and the spring is represented by the equivalent stiffness of the air enclosure acting on the displacement of the compliant nappe centreline. A suited procedure is developed to remove the singularity of the integro-differential operator for Weber numbers less than unity. The investigation is carried out by means of a modal (i.e. time asymptotic) linear approach, which is corroborated by numerical simulations of the governing equation and supported by systematic comparisons with experimental data from the literature, available in the supercritical regime only. As regards the critical regime for the unit Weber number, the major theoretical result is a sharp increase in oscillation frequency as the flow Weber number is gradually reduced from supercritical to subcritical values due to the shift of the prevailing mode from the slow one to the fast one.

High Resolution Particle Image Velocimetry and CH-PLIF Measurements and Analysis of a Shear Layer Stabilized Flame

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
C. W. Foley ◽  
I. Chterev ◽  
J. Seitzman ◽  
T. Lieuwen
Keyword(s):  
Particle Image Velocimetry ◽  
High Resolution ◽  
Shear Layer ◽  
Flow Velocity ◽  
Particle Image ◽  
Flame Stabilization ◽  
Flow Conditions ◽  
Local Flow ◽  
Image Velocimetry ◽  
Flow Velocities

Understanding the mechanisms and physics of flame stabilization and blowoff of premixed flames is critical toward the design of high velocity combustion devices. In the high bulk flow velocity situation typical of practical combustors, the flame anchors in shear layers where the local flow velocities are much lower. Within the shear layer, fluid strain deformation rates are very high and the flame can be subjected to significant stretch levels. The main goal of this work was to characterize the flow and stretch conditions that a premixed flame experiences in a practical combustor geometry and to compare these values to calculated extinction values. High resolution, simultaneous particle image velocimetry (PIV) and planar laser induced fluorescence of CH radicals (CH-PLIF) measurements are used to capture the flame edge and near-field stabilization region. When approaching lean limit extinction conditions, we note characteristic changes in the stretch and flow conditions experienced by the flame. Most notably, the flame becomes less critically stretched when fuel/air ratio is decreased. However, at these lean conditions, the flame is subject to higher mean flow velocities at the edge, suggesting less favorable flow conditions are present at the attachment point of the flame as blowoff is approached. These measurements suggest that blowoff of the flame from the shear layer is not directly stretch extinction induced, but rather the result of an imbalance between the speed of the flame edge and local tangential flow velocity.

scholarly journals ESTIMATION OF DAMAGED AREAS DUE TO THE 2010 CHILE EARTHQUAKE AND TSUNAMI USING SAR IMAGERY OF ALOS/PALSAR

2016 ◽  
Vol III-8 ◽  
pp. 35-42 ◽  
Author(s):  
Pertiwi Jaya Ni Made ◽  
Fusanori Miura ◽  
A. Besse Rimba
Keyword(s):  
Large Scale ◽  
Aerial Photographs ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Tsunami Damage ◽  
Before And After ◽  
Chile Earthquake ◽  
Multi Temporal ◽  
Sar Imagery ◽  
Inundation Map

A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km<sup>2</sup>. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

Influence of the flow velocity on membrane-aerated biofilm reactors: Application of a rotating disk for local flow control

2020 ◽  
Vol 164 ◽  
pp. 107771
Author(s):  
Tadashi Shoji ◽  
Ryuya Itoh ◽  
Tadashi Nittami ◽  
Tatsuto Kageyama ◽  
Miyuki Noguchi ◽  
...  
Keyword(s):  
Flow Control ◽  
Flow Velocity ◽  
Rotating Disk ◽  
Local Flow ◽  
Biofilm Reactors

scholarly journals Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3100 ◽  
Author(s):  
Maria Wetzel ◽  
Thomas Kempka ◽  
Michael Kühn
Keyword(s):  
Flow Velocity ◽  
Power Law ◽  
Elastic Moduli ◽  
Rock Properties ◽  
Local Flow ◽  
Mineral Growth ◽  
Macro Scale ◽  
Elastic Rock ◽  
The Impact ◽  
Flow Velocities

Geochemical processes change the microstructure of rocks and thereby affect their physical behaviour at the macro scale. A micro-computer tomography (micro-CT) scan of a typical reservoir sandstone is used to numerically examine the impact of three spatial alteration patterns on pore morphology, permeability and elastic moduli by correlating precipitation with the local flow velocity magnitude. The results demonstrate that the location of mineral growth strongly affects the permeability decrease with variations by up to four orders in magnitude. Precipitation in regions of high flow velocities is characterised by a predominant clogging of pore throats and a drastic permeability reduction, which can be roughly described by the power law relation with an exponent of 20. A continuous alteration of the pore structure by uniform mineral growth reduces the permeability comparable to the power law with an exponent of four or the Kozeny–Carman relation. Preferential precipitation in regions of low flow velocities predominantly affects smaller throats and pores with a minor impact on the flow regime, where the permeability decrease is considerably below that calculated by the power law with an exponent of two. Despite their complete distinctive impact on hydraulics, the spatial precipitation patterns only slightly affect the increase in elastic rock properties with differences by up to 6.3% between the investigated scenarios. Hence, an adequate characterisation of the spatial precipitation pattern is crucial to quantify changes in hydraulic rock properties, whereas the present study shows that its impact on elastic rock parameters is limited. The calculated relations between porosity and permeability, as well as elastic moduli can be applied for upscaling micro-scale findings to reservoir-scale models to improve their predictive capabilities, what is of paramount importance for a sustainable utilisation of the geological subsurface.

Investigation on Velocity Distribution Around the Wrapping Wire in an Inner Subchannel of Fuel Pin Bundle

2012 ◽  
Author(s):  
Masahiro Nishimura ◽  
Hiroyuki Sato ◽  
Hideki Kamide ◽  
Hiroyuki Ohshima ◽  
Kazuyoshi Nagasawa ◽  
...  
Keyword(s):  
Refractive Index ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Fast Reactor ◽  
Horizontal Plane ◽  
Vertical Plane ◽  
Heat Removal ◽  
Water Model ◽  
Local Flow ◽  
Fuel Pin

A sodium cooled fast reactor is designed to attain a high burn-up core in commercialized fast reactor cycle systems. In high burn-up fuel subassemblies, deformation of fuel pin due to the swelling and thermal bowing may decrease local flow velocity via change of flow area in the subassembly and influence the heat removal capability. Therefore, it is important to obtain the flow velocity distribution in a wire wrapped pin bundle. In this study, water experiments were carried out to investigate the detailed velocity distribution in inner subchannel of the pin bundle geometry. These basic data are not only useful for understanding of pin bundle thermal hydraulics but also code validation. A wire-wrapped 3-pin bundle water model was applied to investigate the detailed velocity distribution in an inner subchannel surrounded by 3 pins with the wrapping wire. The test section consists of an irregular hexagonal acrylic duct tube and fluorinated resin pins which have nearly the same refractive index with that of water and a high light transmission rate. This refractive index matching enables to visualize the inner subchannel through the outer pins. The velocity distribution in the inner subchannel with the wrapping wire was measured by PIV (Particle Image Velocimetry) through two sides of the duct tube. Typical flow velocity conditions in the pin bundle were 1.6m/s (Re = 13,500) and 0.36m/s (Re = 2,700). Feature of stream regime in the subchannel existing wrapping wire was visualized in vertical and horizontal plane. The time averaged velocity field in the horizontal plane was reconstructed from the two vertical plane data in different directions. A detailed simulation code based on FEM was applied to the experimental analysis. The calculated velocity distributions were consistent with the experimental data.

EVALUASI KINERJA DAN PERBAIKAN STRUKTUR BETON GEDUNG PENDINGIN AIR = EVALUATION ON THE PERFORMANCE OF AND REPAIR OF THE CONCRETE STRUCTURE OF A COOLING WATER TOWER

2019 ◽  
Vol 13 (1) ◽  
pp. 9
Author(s):  
Hendro Ahmad Fauzi
Keyword(s):  
Structural Analysis ◽  
Cooling Water ◽  
Structural Performance ◽  
Structural Element ◽  
Design Strength ◽  
Earthquake Loads ◽  
Evaluation Of Performance ◽  
Quality Testing ◽  
Structure Strength ◽  
Safe Condition

This paper presents the evaluation of performance and strenght ofstructure by visual inspection and quality testing of concrete in the field by using aSchmidt hammer and UPV. The evaluation on the performance of the structure,strength columns, beams and plates refer to SNI-2847-2002, in which theimplementation of earthquake loads was based on SNI-1726-2002.The paperproposes improvements and retrofitting necessary structures. SAP2000 is usedfor structural analysis necessary to obtain the required strength values (Ru).Beton2000 is used for structural analysis of existing conditions in order to get thedesigned strength values (Rn). The structure components are in safe condition ifits design strength is greater or equal than required strength or (Ø.Rn) ≥ Ru.Improvements were made to the structural element by coating and injectionmethods.Keywords : structural performance evaluation, improvement AbstrakMakalah ini menyajikan evaluasi kinerja dan kekuatan struktur denganmetode pemeriksaan secara visual dan pengujian mutu beton di lapangandengan alat Schmidt hammer dan UPV. Evaluasi kinerja struktur, kekuatankolom, balok serta pelat mengacu pada SNI-2847-2002, dengan penerapanbeban gempa berdasarkan SNI-1726-2002, serta memberikan usulan perbaikandan perkuatan struktur yang diperlukan. SAP 2000 digunakan untuk analisisstruktur guna mendapatkan nilai kuat perlu (Ru). Beton 2000 digunakan untukanalisis struktur kondisi existing guna mendapatkan kuat rencana (Rn).Komponen struktur dikatakan aman jika kuat rencana lebih besar atau samadengan kuat rencana atau (ф . Rn) ≥ Ru. Perbaikan elemen struktur dilakukandengan metode coating dan injeksi..Kata kunci : evaluasi kinerja struktur, metode perbaikan

Tsunami Fragility — A New Measure to Identify Tsunami Damage —

2009 ◽  
Vol 4 (6) ◽  
pp. 479-488 ◽  
Author(s):  
Shunichi Koshimura ◽  
◽  
Yuichi Namegaya ◽  
Hideaki Yanagisawa ◽  
◽  
...  
Keyword(s):  
Structural Damage ◽  
Field Survey ◽  
Tsunami Inundation ◽  
Fragility Function ◽  
Inundation Depth ◽  
Damage Probability ◽  
Tsunami Damage ◽  
Historical Data Analysis ◽  
Quantitative Manner ◽  
Tsunami Fragility

Tsunami fragility (fragility curve, or fragility function) is a new measure, we propose, for estimating structural damage and fatalities due to tsunami attack, by integrating satellite remote sensing, field survey, numerical modeling, and historical data analysis with geographic information system (GIS). Tsunami fragility is expressed as the structural damage probability or fatality ratio related to hydrodynamic features of tsunami inundation flow, such as inundation depth, current velocity and hydrodynamic force. It expands the capability of estimating potential tsunami damage in a quantitative manner.

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