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1.
Cairo City has a large number and different forms of Islamic archaeological sites, in particular, at El-Gammalia and El-Moez
streets, as well as Coptic archaeological sites, e.g. at Mari Gergis. Human interference and activities at these historical
areas resulted in flooding such sites’ foundations with domestic water, deteriorating its basal courses by salt weathering.
The 1992 earthquake is another natural environmental hazard severely affecting many of these sites. The aim of the current
study is to examine some factors (of bedrock and buildings) that are expected to control building susceptibility to damage
by earthquakes by taking 38 Islamic archaeological sites in the El-Gammalia area as a representative case study. Detailed
field recordings of site damage category before and after the quake and continued recording of damage features generated by
the 1992 quake over the last 14 years, measuring depth to sub-surface water, measuring buildings’ height before the quake
and bedrock sampling at these sites for geotechnical investigations were all considered for achieving this aim. The data has
been processed mathematically and graphically (using the Excel package) to examine the main factors responsible for building
susceptibility to damage by earthquakes. The selected archaeological sites give an excellent representation of the factors
controlling building susceptibility to damage by quakes; it is found that the sites with heights (before the quake) ranging
from 12 to 14 m are the most affected ones; the sites with the highest damage category before the quake were more susceptible
to more damage by the quake; the sites that had been built on alluvium soil were more affected than those built on the Eocene
limestone. The age of these sites has, to a small extent, indirect control on sites’ susceptibility to damage by the quake,
particularly in parts flooded with domestic water (i.e. affected by salt weathering). The depth to sub-surface water is an
effective parameter on sites’ basal courses (through salt weathering), which, indirectly, control a building’s susceptibility
to quakes, particularly where the depth of water ranges from 0.6 to 1.6 m in alluvium bedrock. The alluvium soil at the study
area has a liquid limit ranging from 62% to 82%, plastic limit from 37% to 86% and plasticity index from 26% to 46% and free
swelling from 27% to 81%. These geotechnical limits for such alluvium bedrock indicate that its clay minerals are mostly montmorrillonite. 相似文献
2.
Seismic risk assessment of buildings in urban areas: a case study for Denizli,Turkey 总被引：3，自引：2，他引：1
This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field
study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced
to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli,
a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in
a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological
and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during
past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226
parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural
system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to
assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing
the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant
casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings
also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more
stories, (2) pre-1975 constructed buildings, and (3) buildings with 3–5 stories. The future studies for evaluating and reducing
seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled
in a Geographical Information System (GIS) database. 相似文献
3.
J. D. Rockaway 《Environmental Geology》1990,16(1):29-34
The series of earthquakes that occurred along the New Madrid Fault System in 1811 and 1812 probably was as large as any earthquakes that ever occurred in eastern North America. The magnitude of each of the four major shocks exceeded M2 = 8.4, and the effects of these shocks were felt with a Modified Mercalli Intensity V or greater over approximately 2.5 million km2. Because the epicenters were located in a sparsely settled region of the American frontier, there was little loss of life or damage. However, eyewitness accounts of those who lived through the shocks have provided striking accounts of the high levels of ground motion the region experienced. Thus, the historical record gives engineering geologists a good indication of the catastrophic damage that could result if earthquakes of similar magnitude would occur today. 相似文献
4.
The January 25, 1946 earthquake in the central Valais region in southwest Switzerland was the strongest for the last 150 years.
It reached an epicentral intensity Io of VIII in the area of Sierre. The Swiss Earthquake Catalogue (ECOS 2002) assigns a
moment magnitude of Mw = 6.1 to the event. Assessment of recordings from European stations resulted in a moment magnitude
of 5.8 (Bernardi et al. 2005). The earthquake caused moderate to high damage within a circle of about a 25 kilometer radius.
Slight damage occurred up to a distance of 200 kilometers from the epicenter.
The goal of this study was to reconstruct the damage field and consider its possible site-effects. We used an approach combining
historical research with seismo-/geological investigation including a large number of experiments measuring the fundamental
frequency of resonance and the shear-wave velocities of the sedimentary layers, using the characteristics of ambient vibration.
This kind of research is relevant, since a huge alpine valley characterizes the Valais region, showing ground conditions that
make site-effects likely for earthquakes. While we searched for damage in an unlimited area, our investigation of site-effects
was limited to the Rhone valley and to Sion and Sierre in the central Valais region in particular. 相似文献
5.
Hydraulic and flood-loss modeling of levee,floodplain, and river management strategies,Middle Mississippi River,USA 总被引：4，自引：2，他引：2
In this investigation, four scenarios were used to quantify the balance between the benefits of levees for flood protection
and their potential to increase flood risk using Hazards U.S. Multi-Hazard flood-loss software and hydraulic modeling of the
Middle Mississippi River (MMR). The goals of this study were (1) to quantify the flood exposure under different flood-control
configurations and (2) to assess the relative contributions of various engineered structures and flood-loss strategies to
potential flood losses. Removing all the flood-control structures along the MMR, without buyouts or other mitigation, reduced
the average flood stages between 2.3 m (100-year flood) and 2.5 m (500-year), but increased the potential flood losses by
$4.3–6.7 billion. Removing the agricultural levees downstream of St. Louis decreased the flood stages through the metro region
by ~1.0 m for the 100- and 500-year events; flood losses, without buyouts or other mitigation, were increased by $4.3–6.7 billion. Removing the agricultural levees downstream of St. Louis decreased the flood stages through the metro region
by ~1.0 m for the 100- and 500-year events; flood losses, without buyouts or other mitigation, were increased by 155 million
for the 100-year flood, but were decreased by $109 million for the 500-year flood. Thus, agricultural levees along the MMR
protect against small- to medium-size floods (up to the ~100-year flood level) but cause more damage than they prevent during
large floods such as the 500-year flood. Buyout costs for the all the buildings within the 500-year floodplain downstream
of urban flood-control structures near St. Louis are ~40% less than the cost of repairing the buildings damaged by the 500-year
flood. This suggests large-scale buyouts could be the most cost-effective option for flood loss mitigation for properties
currently protected by agricultural levees. 相似文献
6.
Applying the HAZUS-MH software tool to assess seismic risk in downtown Ottawa,Canada 总被引：3，自引：3，他引：0
The aim of this paper is to present earthquake loss estimations for a portion of downtown Ottawa, Canada, using the HAZUS-MH
(Hazards United States Multi-Hazard) software tool. The assessment is performed for a scenario earthquake of moment magnitude
6.5, at an epicentral distance of 15 km, occurring during business hours. A level 2 HAZUS-MH analysis was performed where
the building inventory, microzonation studies, and site-specific ground motion hazard maps (2% exceedence probability in 50 years)
were all improved based on local information. All collected data were assembled into a set of standard geodatabases that are
compatible with the HAZUS-MH software using a GIS-specific procedure. The results indicate that the greatest losses are expected
in unreinforced masonry buildings and commercial buildings. Sensitivity studies show that soil classes, the vulnerability
of schools, and the spatial scale of loss estimations are also important factors to take into account. 相似文献
7.
Earthquake losses due to ground failure 总被引：2，自引：0，他引：2
Juliet F. Bird 《Engineering Geology》2004,75(2):147-179
Ground shaking is widely considered to be the primary cause of damage to structures, loss of life and injuries due to earthquakes. Nonetheless, there are numerous examples of earthquakes where the losses due to earthquake-induced ground failure have been significant. Whereas ground shaking causes structural and non-structural damage, with associated loss of function and income, ground failure is less likely to cause spectacular structural collapses, but is frequently the cause of major disruptions, particularly to lifelines, which can lead to prolonged loss of function and income, even for undamaged areas.Those involved in earthquake loss modelling are currently presented with three choices with respect to the incorporation of ground failure: they can choose to ignore it, assuming that any estimation of losses caused by shaking would effectively subsume the impact of these secondary hazards; they can include ground failure in a simple manner, using published approaches based upon qualitative data and a large degree of judgement; or, they can opt for a detailed site- or region-specific assessment of damage due to ground failure, with the associated time and expense.This paper presents a summary of the principal features of earthquake losses incurred in damaging earthquakes over the last 15 years. Survey data are impartially analysed, considering both ground failure and ground shaking as sources of damage, and their relative contribution to overall damage in each section of the regional infrastructure is presented. There are many other variables influencing these contributions, including the size of the earthquake, the economic status of the affected region, local geology and terrain and the building stock, which have been considered.The findings of the study are discussed from the point of view of loss modelling and which components of a model should merit the most time and resource allocation. The general assumption that ground shaking is the principal cause of damage and loss is strongly supported by the study. However, there are a number of scenarios identified where the failure to appropriately include the effects of ground failure would lead to unrealistic loss projections. Such scenarios include the assessment of building losses in small zones rather than on a regional basis, and the incorporation of lifeline damage or disruption and indirect losses into a model. 相似文献
8.
汶川8.0级地震液化震害及特征 总被引：3，自引：1，他引：2
通过现场详细地调查,归纳总结了汶川地震液化导致的工程震害的现象、分布、规律和特征。结果表明,此次地震液化震害现象显著,位于德阳地区的3个液化区域震害严重,都江堰地区、绵阳游仙区以及江油市区的3个液化区域震害中等,其他地区轻微,液化震害分布与液化分布有一定关系,但二者有所不同;液化场地上房屋均不同程度受损,其中结构性差的房屋会直接倒塌,设有圈梁、构造柱的房屋,液化也会导致其整体倾斜、下沉、开裂;学校液化震害具有典型性,部分校区大面积液化,地裂缝纵横,地基不均匀沉降严重,主体结构开裂、倾斜,功能丧失。这次液化震害具有3个显著特征:(1)只要液化出现的地方,震害均比周围重,没有减震现象;(2)Ⅵ度区不仅有液化现象,而且有明显的液化震害;(3)液化伴随地裂缝,是构成此次地震液化震害的主因。 相似文献
9.
In quantitative risk analyses for natural hazards, vulnerability can be expressed as the ratio of reconstruction, replacement or reproduction expenses due to a damage caused by a certain process intensity and the original value of the element at risk exposed. To discuss the building vulnerability under debris flow events, the ratio is mostly related to debris flow inundation height, building materials and building values. Different types of buildings would resist to the impact of debris flows differently, resulting in different damage levels even under the same inundation height. After debris flow events, the damages to a building include the content loss and the structure loss, which is also variable due to the individual building conditions. This study proposes a flowchart to establish building vulnerability curves through estimating the damages to buildings after debris flow hazards. The losses of content and structure are firstly calculated separately to obtain the loss ratios with respect to original buildings. Secondly, by combining the content and structure loss ratio, the building vulnerability function is derived. In this paper, the original building content value was obtained from governmental statistic records and was based on the market price, and the structure value was received from a regional architecture office. The losses resulting from debris flow impacts were synthetically derived following field surveys. To combine the content and structure losses, a unit building with a floor area of 60?m2 was assumed. The result shows that due to a higher percentage of content value compared with the total building value, the loss ratio resulting from debris flows in Taiwan is higher compared with European studies, in particular with respect to high-frequency but low-magnitude events. The concept of obtaining building vulnerability is particularly suitable for regions where well-documented building loss records are unavailable. 相似文献
10.
Losses resulting from winter storms contribute a significant part to the overall losses among all natural hazards in most
mid-latitude European countries. A realistic assessment of storm risk is therefore essential for prevention and coping measures.
The paper presents a framework for probabilistic storm risk assessment for residential buildings which is exemplarily performed
for Germany. Two different approaches are described, and results are presented. The hazard-based approach brings together
hazard, vulnerability and building assets to calculate risk curves for each community. The storm-based approach uses loss
information from past storm events to calculate statistical return periods of severe storms. As a result, a return period
of 83 years to the most severe storm series in 1990 is calculated. Average annual losses of €170 million to residential buildings
are calculated for all over Germany. The study demonstrates how the approaches complement each other and how validation is
performed. 相似文献
11.
Al Hoceima is one of the most seismic active regions in north of Morocco. It is demonstrated by the large seismic episodes reported in seismic catalogs and research studies. However, seismic risk is relatively high due to vulnerable buildings that are either old or don’t respect seismic standards. Our aim is to present a study about seismic risk and seismic scenarios for the city of Al Hoceima. The seismic vulnerability of the existing residential buildings was evaluated using the vulnerability index method (Risk-UE). It was chosen to be adapted and applied to the Moroccan constructions for its practicality and simple methodology. A visual inspection of 1102 buildings was carried out to assess the vulnerability factors. As for seismic hazard, it was evaluated in terms of macroseismic intensity for two scenarios (a deterministic and probabilistic scenario). The maps of seismic risk are represented by direct damage on buildings, damage to population and economic cost. According to the results, the main vulnerability index of the city is equal to 0.49 and the seismic risk is estimated as Slight (main damage grade equal to 0.9 for the deterministic scenario and 0.7 for the probabilistic scenario). However, Moderate to heavy damage is expected in areas located in the newer extensions, in both the east and west of the city. Important economic losses and damage to the population are expected in these areas as well. The maps elaborated can be a potential guide to the decision making in the field of seismic risk prevention and mitigation strategies in Al Hoceima. 相似文献
12.
We estimate the losses due to 10 scenario earthquakes in 150 settlements of the United Arab Emirates (UAE). For southern Iran, we use four source zones and the maximum magnitudes in them as determined by GSHAP (7.2 M 8.1). For six local scenario earthquakes, we use the range 5.5 M 6.5, place the sources mainly on mapped faults and vary the distance to major cities from 10 to 60 km. In the test case of the Masafi earthquake (M5, 11 March 2002), the method and data bank we use yield the correct results, suggesting that our approach to the problem is valid for the UAE. The sources in Iran are expected to cause only minor damage, except for an M8.1 earthquake in the Makran region. For such an event we expect some deaths, several hundred injured and a loss of 3–6% of the value to the building stock in the northeastern UAE, including Oman. The losses for local scenarios with epicenters in the unpopulated areas of the UAE and for scenarios with M < 5.8 are estimated to be minor. Because the two major mapped faults run through several of the large cities, scenarios with short epicentral distances from cities have to be considered. Scenarios with M6 near cities lead to estimates of about 1000 ± 500 deaths, and several thousand injured. Most buildings are expected to be damaged to a moderate degree and the loss to buildings is estimated around 1/4of their value. If the magnitude should reach 6.5, the losses to humans and to building value could be staggering. These estimates are approximate because: (1) there exists no local seismograph network that could map active faults by locating microseismicity; (2) there exist no historically old buildings that could serve as tests for effects due to strong ground motion in the past; (3) there exist no microzonation of the subsurface properties in this region of unconsolidated building ground; (4) there exist no detailed inventory of building fragility. Nevertheless, our conclusion that there exists a substantial seismic risk in the UAE is reliable, because our method yields accurate results in the cases of earthquakes with known losses during the last several decades in the Middle East. 相似文献
13.
The seismic events recorded at two accelerographs installed at Sellano (central Italy) during the 1997–1998 Umbria seismic sequence, one on detritic material, at the historical centre, and the other one on rock, about 200 m distant, were analysed in terms of spectral amplification of the historical centre site. Epicentres were mainly concentrated in the north and south-east directions of Sellano area. The SH wave component average amplifications were evaluated from the smoothed Fourier spectral ratios of the recordings on soil and rock sites, along the two main epicentral lines. Similar amplifications resulted, with two main peaks in the frequency range of 3–5 Hz, corresponding to the eigenfrequencies of the damaged buildings. Shear velocities of the shallowest 30 m of soils were obtained by FTAN measurements along refraction seismic spreadings, and utilized to compute spectral amplification of soil station to rock station along the geological cross sections. A good agreement was found between observed Fourier spectral ratios and the computed 2D amplification modelling, which explains the damage level of the historical buildings beside the degraded conditions of brick masonry. 相似文献
14.
15.
Seismic hazard maps are constructed by extrapolating from the frequency of small earthquakes, the annual probability of large, infrequent, earthquakes. Combining the potential contribution from all seismically active volumes, one calculates the peak ground acceleration with a probability to be exceeded by 10?% in 50?years at any given point. The consequential risk, the losses to be expected, derives from the damage the calculated shaking causes to buildings, and the impact on occupants due to collapsing structures. We show that the numbers of fatalities in recent disastrous earthquakes were underestimated by the world seismic hazard maps by approximately two to three orders of magnitude. Thus, seismic hazard maps based on the standard method cannot be used to estimate the risk to which the population is exposed due to large earthquakes. 相似文献
16.
Overview of Taiwan Earthquake Loss Estimation System 总被引：2，自引：1，他引：2
The National Science Council (NSC) of Taiwan started the HAZ-Taiwan project in 1998 to promote researches on seismic hazard
analysis, structural damage assessment, and socio-economic loss estimation. The associated application software, “Taiwan Earthquake
Loss Estimation System (TELES)”, integrates various inventory data and analysis modules to fulfill three objectives. First,
it helps to obtain reliable estimates of seismic hazards and losses soon after occurrence of large earthquakes. Second, it
helps to simulate earthquake scenarios and to provide useful estimates for local governments or public services to propose
their seismic disaster mitigation plans. Third, it helps to provide catastrophic risk management tools, such as proposing
the seismic insurance policy for residential buildings. This paper focuses on the development and application of analysis
modules used in early loss estimation system. These modules include assessments of ground motion intensity, soil liquefaction
potential, building damage and casualty. 相似文献
17.
Efthymios Lekkas Spyridon Mavroulis Panayotis Carydis Vassiliki Alexoudi 《Geotechnical and Geological Engineering》2018,36(4):2109-2142
On Tuesday, November 17, 2015 at 07:10:07 (UTC) a strong earthquake struck Lefkas Island (Ionian Sea, Western Greece) with magnitude Mw 6.4, depth of about 6 km and epicenter located 20 km southwest of Lefkas town. It was felt in Lefkas Island and the surrounding region and caused the death of two people, the injury of eight others, many earthquake environmental effects (EEE) and damage to buildings and infrastructures. Secondary EEE were observed in western Lefkas and classified as ground cracks, slope movements and liquefaction phenomena. Primary effects directly linked to surface expression of seismogenic source were not detected in the field. The maximum intensity VIIIESI 2007 was assigned to large-volume slope movements along western coastal Lefkas. Damage to buildings was mainly observed in villages located in Dragano-Athani graben arranged almost parallel to the northern segment of the Cephalonia Transform Fault Zone (Lefkas segment). Among structures constructed with no seismic provisions, the stone masonry buildings and monumental structures suffered most damage, while the traditional buildings of the area with dual structural system performed relatively well and suffered minor damage. Reinforced-concrete buildings were affected not so much by the earthquake itself but by the generation of secondary EEE. The maximum seismic intensities VIIIEMS-98 were assigned to villages located in Dragano-Athani graben due to very heavy structural damage observed on masonry buildings mainly attributed to the combination of the recorded high PGA values, the poor antiseismic design and construction of buildings and the geological and tectonic structure of the affected area. 相似文献
18.
Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologies are used to evaluate the vulnerability indexes of buildings and building stocks. On the other hand, a vulnerability model is calibrated by means of experimental and numerical investigations on prototype buildings representative of the most recurrent typologies. In the final framework, the vulnerability index, calculated through simplified assessment forms, is linked to the seismic intensity expressed by the peak ground acceleration and associated with an index of damage expressing the economical loss. The procedure has been tested on the urban center of Lampedusa island (Italy) providing as the output vulnerability index maps, vulnerability curves, critical PGA maps, and estimation of the economical damage associated with different earthquake scenarios. The application of the procedure can be suitably repeated for medium-to-small urban areas, typically recurring in the Mediterranean by carrying out each time a recalibration of the vulnerability model.
相似文献19.
Empirical, theoretical or hybrid methods can be used for the vulnerability analysis of structures to evaluate the seismic
damage data and to obtain probability damage matrices. The information on observed structural damage after earthquakes has
critical importance to drive empirical vulnerability methods. The purpose of this paper is to evaluate the damage distributions
based on the data observed in Erzincan-1992, Dinar-1995 and Kocaeli-1999 earthquakes in Turkey utilizing two probability models—Modified
Binomial Distribution (MBiD) and Modified Beta Distribution (MBeD). Based on these analyses, it was possible (a) to compare
the advantages and limitations of the two probability models with respect to their capabilities in modelling the observed
damage distributions; (b) to evaluate the damage assessment for reinforced concrete and masonry buildings in Turkey based
on these models; (c) to model the damage distribution of different sub-groups such as buildings with different number of storeys
or soil conditions according to the both models. The results indicate that (a) MBeD is more suitable than the MBiD to model
the observed damage data for both reinforced concrete and masonry buildings in Turkey; (b) the sub-groups with lower number
of stories are located in the lower intensity levels, while the sub-groups with higher number of stories depending on local
site condition are concentrated in the higher intensity levels, thus site conditions should also be considered in the assessment
of the intensity levels; (c) the detailed local models decrease the uncertainties of loss estimation since the damage distribution
of sub-groups can be more accurately modelled compared to the general damage distribution models. 相似文献
20.
This paper is concerned with an investigation of the damage to residential buildings in two areas within Gilan and Zanjan provinces, Iran, caused by the Manjil-Rudbar earthquake of 20 June 1990. A statistical correlation between the observed ground motion and the damage to the residential buildings is derived for overall damaged buildings and expressed as the vulnerability function. The loss function is calculated by combining the seismic hazard with the vulnerability function.The study of vulnerability and annual seismic hazard shows that the specific annual risk for the range of motion of 0.18 to 0.5 g is equal to 0.02. This indicates that the specific risk for semi-engineered residential buildings with a lifetime of 20 years is about 33%. This study also shows that in large cities, such as Tehran, located in seismic areas, the extent of damage according to the vulnerability function will be 45 and 70% for expected maximum accelerations of 0.3 and 0.4 g, respectively. 相似文献