Soil sealing,population structure and the socioeconomic context: a local-scale assessment

In the most recent decades European urban regions underwent functional changes reflecting heterogeneous land-use patterns and specific urban footprints. Several mono-centric cities shifted towards a scattered development with impact on the socio-spatial structure. Discontinuous expansion determined, in some cases, a net increase in land consumption. Using a multivariate exploratory approach, the present study analyzes the spatial relationships between 14 morphological variables and 22 socioeconomic indicators in Rome’s province. The aim of this study was to identify the demographic and socioeconomic indicators most associated to the transition from a mono-centric and semi-compact morphology towards a more dispersed settlement structure based on different sealing profiles observed at the local scale. Four groups of socioeconomic indicators (population structure, job market, economic specialization and settlement characteristics) associated to different sealing profiles (low, medium and high imperviousness) were identified and local municipalities classified accordingly. Although the urban–rural axis maintains an important role in the spatial organization of Rome’s province, other variables were found associated to areas with moderately low imperviousness, evidencing a specific demographic structure and persisting socioeconomic disparities at the base of the settlement model observed at the regional scale.     

Damage field and site effects: multidisciplinary studies of the 1964 earthquake series in Central Switzerland

Central Switzerland shows comparatively high seismic activity by Swiss standards. Many historical earthquakes are known and several of them caused damage. The last major event dates back to 1964 and has the characteristics of an earthquake swarm. Among dozens of felt shocks were two main shocks (Mw = 5 and 5.7) that moderately damaged a limited area with hundreds of buildings suffering loss. Our aim here was to reconstruct the damage field and to analyze whether it was influenced by site effects. Given the existence of a contemporary damage assessment and other historical sources, we could describe the damage field in detail. For about 95% of the affected buildings, we could reconstruct the location and extent of loss, using assessments from the European Macroseismic Scale (EMS 98). Spatial analysis of the resulting data showed that most losses were concentrated in the villages of Sarnen and Kerns. Damage to residential houses and barns was by far most frequent (90%), but expensive losses to the relatively few sacral buildings were responsible for almost 50% of the repair costs. We compared the damage data with deposit thickness and soil composition and carried out field experiments using H/V spectral ratios to measure the fundamental frequency of ground resonance at 75 sites to estimate the frequency band in which amplification occurs. Our results show that locations on both thick fluviatile sediments and large alluvial cones showed higher intensities than did other ground types. Moreover, at some sites, intensity was probably increased by a layer of weathered rock below thin deposits.     

Impact of local site conditions on portfolio earthquake loss estimation for different building types

This article presents a sensitivity analysis investigating the impact of using high-resolution site conditions databases in portfolio earthquake loss estimation. This article also estimates the effects of variability in the site condition databases on probabilistic earthquake loss ratios and their geographical pattern with respect to structural characteristics of different building types. To perform the earthquake loss estimation here, the OpenQuake software developed by Global Earthquake Model is implemented in Clemson University’s supercomputer. The probabilistic event-based risk analysis is employed considering several notional portfolios of different building types in the San Francisco area as the inventory exposure. This analysis produces the stochastic event sets worth for 10,000 years including almost 8000 synthetically simulated earthquakes. Then, the ground motion prediction equations are used to calculate the ground motion per event and incorporate the effect of five site conditions, on amplifying or de-amplifying the ground motions on notional building exposure locations. Notional buildings are used to account for various building characteristics in conformance with the building taxonomy represented in HAZUS software. The HAZUS damage functions are applied to model the vulnerability of various structural types of buildings. Finally, the 50-year average mean loss and probabilistic loss for multiple values for probability of exceedance (2, 10, 20, and 40%) in 50 years are calculated, and the impact of different site condition databases on portfolio loss ratios is investigated for different structural types and heights of buildings. The results show the aggregated and geographical variation of loss and loss ratio throughout the region for various site conditions. Comparing the aggregated loss and loss ratio, while considering different databases, represents normalized differences that are limited to 6% for all building taxonomy with various heights and for all PoEs. However, site-specific loss ratio errors are significantly greater and in some cases are more than 20%.     

Assessment of physical vulnerability and potential losses of buildings due to shallow slides

Physical vulnerability (PV) of buildings and associated potential losses (PLs) due to the occurrence of shallow slides are semi-quantitatively assessed at the regional scale in a municipality located in the North of Portugal. This work has four main purposes: (1) to identify and characterize the built environment exposed to shallow slides in the study area; (2) to assess the PV of each building type taking into account the building resistance (BR) and the landslide magnitude (LM); (3) to evaluate the economic value (EV) of each single exposed building using cadastral and market values; and (4) to estimate PLs on buildings due to landslide activity. The analysis is made for each single building of the study area, and this is an innovative contribution of this work. The semi-quantitative methodology to assess PV of buildings exposed to shallow translational slides combines the LM and the BR, which is empirically obtained weighting a set of parameters related to building characteristics. The quantification of the EV of buildings was carried out using an adaptation of the calculation formula used by the Portuguese Tax Services to determine the taxable value of buildings in Portugal. PLs result from the product between PV of the exposed buildings and their EV in euros. The overlapping of PLs of buildings with an available landslide susceptibility map, although does not provides any quantified risk analysis, provides valuable information to be used by spatial planning and civil protection stakeholders.     

Field meeting report: the geology of some West London Churches, 22nd September 2012

This excursion report describes briefly the ecclesiastical geology of seven localities in West London. It reveals that building stones related to local geology were particularly important in the construction of early churches. For this reason wall building fabric analyses of churches are also able to indicate an enormous amount of local geological information. Where London Basin rocks were unsuitable for structural aspects of these churches it was sometimes necessary to use rock types from more distant sources.     

Natural building stones of Mexico–Tenochtitlán: their use, weathering and rock properties at the Templo Mayor, Palace Heras Soto and the Metropolitan Cathedral

In the Aztec period and in colonial times different natural stones originating in the Valley of Mexico were used for building construction. Stone weathering was investigated onsite at various historical buildings within the old quarter of Mexico City. In this study, different aspects of weathering and deterioration at three significant historical buildings will be presented, the Aztec excavation site Templo Mayor, the Metropolitan Cathedral, and the colonial palace of the dukes of Heras Soto. Petrophysical properties of the main building stones of these structures were investigated like density, porosity, pore radii distribution, water uptake rate and coefficient, thermal and hygric expansion, and the mechanical properties of uniaxial compressive strength. A relationship between single critical property values, according to anisotropy fabric characteristics, and specific weathering forms could be deduced.     

Understanding different perspectives on the preservation of community and heritage buildings in the Wellington Region,New Zealand

The Canterbury (New Zealand) earthquake sequence of 2010–2012 caused unexpectedly extreme levels of damage and disruption, being an unparalleled event in New Zealand in terms of the damage extent. Christchurch’s heritage buildings were seriously damaged during these events, with churches especially affected in 22 February 2011 M _w 6.2 earthquake. During this earthquake, a total of 84% of the heritage unreinforced stone and 81% of the clay brick masonry churches in the Canterbury region were either considered unsafe (receiving red placards) or with restricted access (yellow placards). Following the earthquakes, authorities across New Zealand are reassessing the capacity of older buildings to resist earthquakes. Current legislation requires that a building judged as earthquake prone either be strengthened by retrofitting or be demolished within a legislated number of years. Many building owners are facing the problems of owning earthquake-prone buildings and lacking the funding to upgrade. This affects both community and heritage buildings, resulting in the likely abandonment or demolition of some buildings. To address the problem of the balance between life safety and preservation in the Wellington Region, this project gathered and compared the perspectives of the general public, church communities, heritage specialists, professional engineers, and local authorities to assist in balancing the interests of these stakeholders. As a result of the findings, several recommendations have been provided that include standardizing structural assessment processes and training, feasibility of additional public funding to upgrade buildings, new signage to increase public awareness of earthquake-prone buildings, and regular communication among stakeholders to understand and resolve differences.     

Social vulnerability assessment to seismic risk using multicriteria analysis: the case study of Vila Franca do Campo (S?o Miguel Island, Azores, Portugal)

The increase in the frequency and magnitude of disasters triggered by earthquakes in different regions of the Earth is a major challenge to contemporary societies. The awareness that disasters and risk are processes structured on spatial?Ctemporal interactions maintained at the social-ecological system between the natural hazards and the vulnerabilities of socioeconomic, political and physical nature becomes utterly important in the increase of social systems?? resilience. Thus, the assessment of social vulnerability plays a decisive role in understanding the factors that distinguishes individuals, households and communities, in terms of their ability to anticipate, cope with, resist to and recover from the impact of disasters triggered by natural hazards. This article presents a geographic information system (GIS)-based approach model to assess the social vulnerability to seismic risk using multicriteria analysis (MCA) techniques, in a group decision-making process. The methodology applied to the municipality of Vila Franca do Campo (S?o Miguel Island, Azores, Portugal) identified moderate social vulnerability values at the neighbourhood level and higher social vulnerability values for the built environment and demographic characteristics of the social groups. The social vulnerability patterns make a clear distinction between the older/historical urban cores and the new urban areas. In the first case, the presence of ancient buildings constructed with materials of low resistance to earthquakes coupled with a higher population density and the traits of demographic and socioeconomic frailties of the social groups, results in higher vulnerability values. This pattern is common in the historic centre of S. Miguel district, Ribeira das Taínhas, northern areas of água de Alto and western and eastern neighbourhoods of Ponta Gar?a. The new urban areas, mainly found in S. Pedro, central areas of água de Alto, S. Miguel and Ponta Gar?a districts, have lower values of social vulnerability due to changes in the built, demographic and socioeconomic environments. Results recommend the integration of social vulnerability indexes into seismic risk mitigation policies and emergency management planning.     

Uses and Limitations of Socioeconomic Indicators of Community Vulnerability to Natural Hazards: Data and Disasters in Northern Australia

Advances in computer technology have made very large databases easily accessible to users and managers. The census and land databases are of enormous use to hazard managers and planners. An extensive literature has identified groups of social, economic and demographic indicators that may be combined with physical and land data to predict and categorise levels of community vulnerability. Impact scenario mapping can be very precise and impressive in its detail, but a range of constraints, such as ageing of the data, the arbitrary nature of boundaries, problems of weighting indicators, and categorisation of vulnerability, impose limitations on the use of socioeconomic indicators to predict community vulnerability.     

Response of Strata and Buildings to Blast Induced Vibrations in the Presence and Absence of a Tunnel

Blast induced vibrations form an inevitable and major part of modern day construction. The changes that happen to the strata or buildings surrounding the blast are evident in a fraction of a second. Effect of damage is more pronounced in the absence/presence of the tunnel. The vibration produced due to blast may be induced due to a deep underground explosion, a surface explosion or even an in-tunnel explosion. In this study the above three situations are numerically modeled by a Distinct Element software 3DEC (3.0). Soil properties are varied representing soft and stiff strata. Further, three velocity time histories of 2, 45 and 85 Hz are used as an input in the model and are applied at three different boundaries of the model. Results of the analysis reveal that the response of building in softer strata and lower frequencies led to greater magnification of velocities and displacements compared to response of buildings in stiff strata. Presence of the tunnel led to reduction of peak velocity (PV’s) and displacements at the building top due to damping effect. PV’s at the top floor were greater than the PV’s at the bottom floor and there was an upliftment of the soil mass at the ground level. However, the upliftment in the presence of the building was lower than the upliftment in the absence of the building. Stress in the tunnel lining increased in the presence of the building, however percentage reduction of stress depends on the number of building stories.     

Radon migration into different building types at medium and low south-eastern flank of Mt Etna (Sicily): connection with the volcanic activity

Indoor Radon concentrations have been carried out simultaneously at the villages of S. Venerina and Acireale, which are located on the south-eastern flank of Mt. Etna volcano. Both investigation sites are partially affected by the same fault system, which plays an important role in the dynamics of the volcano, especially before and during eruptive periods. Measurements were performed in the period from January 2006 until April 2006, just prior to an eruption which took place on 14th July 2006. Indoor Radon monitoring at S. Venerina, was carried out at two buildings located nearby, characterized by a different type of construction. These buildings were chosen because they can be considered as representative of both the historical centre and the new neighbourhoods of the village. At the same time, a Radon active monitor was operating in-soil near the two aforesaid edifices. Cross-correlation analysis between the in-soil one with both the indoor S. Venerina Radon series indicated different temporal correlation, probably due to the different types of building foundations and constructive materials of their walls, both causing the different indoor accumulation. S. Venerina’s indoor Radon values taken at the new building showed similar trends and the same anomalies as the ones recorded at Acireale. The simultaneous increase in indoor Radon concentration was observed at both sites from the last ten days of March, when a significant increase in the CO₂ efflux was recorded. Increases in volcanogenic gases occurred very probably throughout an inflating state of the volcano during the pre-eruptive period, which caused the wide opening of the fractures. Lastly, variations in indoor Radon concentrations observed before an eruption, indicate the suitability of the investigated sites for in-soil Radon monitoring at a low altitude of the south-eastern flank of Mt. Etna. Moreover, in this place repeated and long period Radon indoor measurements should be carried out due to high potential indoor accumulation which depends from the volcanic activity, as this could constitute a serious danger to public health.     

泥石流作用下建筑物易损性评价方法分析与评价

建筑物易损度评价作为泥石流易损度评价的重要组成部分,其研究是实现城镇及居民点泥石流风险定量化和风险管理的必要环节。综述近30年来,泥石流作用下建筑物易损度研究的发展过程,并指出以统计分析方法建立的建筑物易损度曲线普适性差且力学机理不明等问题,提出数值计算和模型实验的手段获取建筑物结构易损度的机理模型。由于建筑物易损度研究问题本身的复杂性,统计分析方法仍将作为建筑物易损度研究的重要手段,力学机理明晰的研究方法则将成为今后研究的难点和热点。此外,地震、滚石、雪崩等类似灾种的易损度研究方法和成果可被借鉴到泥石流领域。针对灾害中因结构破坏引发人员伤亡的情况,建议采用时间概率和基于条件概率的事件树方法计算建筑物内人员易损度。最终形成综合结构和人员易损度研究成果的建筑物易损度评价方法。     

Comparison between radiocarbon and varve dating in Lake Lampellonjärvi, south Finland

The annual nature of organic laminations in the sediment from a small lake, Lampellonjärvi (61°04'N; 25°04'E), was determined. The core was obtained using an in situ freezing method and the laminations were checked by a detailed microscopical analysis of adhesive tape preparations. A series of six radiocarbon dates were obtained for levels in the core which had previously been dated by means of varve counts to ages between A.D. 182 and AD. 1513. The radiocarbon dates were between 547 and 1525 years older. Two additional ¹⁴C dates from the lower part of the same profile (ca. 1880 B.C. and ca. 3100 B.C.), however, gave expected results. Erosion of old organic terrestrial material due to agricultural activity in the surroundings of the lake was assumed to have been the cause of abnormally old radiocarbon ages. Dates from the pre-agricultural period had a deviation from varve years similar to the difference between tree rings, historical documents and radiocarbon dating recorded in other studies.     

Determination of deterioration of the main facade of the Ferit Paşa Cistern by non-destructive techniques (Konya,Turkey)

Building stones have long been one of the most widely used construction materials in the world. Building stones used in historical monuments are deteriorated partly or completely depending on the environmental and atmospheric effects. In recent years, non-destructive test methods have been used to assess deterioration of building stones used in historical monuments. Gödene stone is one of the building stones being widely used in the historical buildings in the Konya region, Central Anatolia. The most deterioration effects are observed in the Ferit Pa?a Cistern among the historical structures built with Gödene stone in the region. The aim of this study is to assess the deteriorating effects in the street façade of the Ferit Pa?a Cistern via non-destructive testing methods (Schmidt hardness rebound value, P-wave velocity, humidity measurement and thermal imaging) and create maps of deteriorated features. Turkey’s historic places are integrated to Turkish culture, efforts are made to conserve heritage through rehabilitation. Therefore, this study will help developers and federal managers during the project planning stage by providing technical data.     

Building Damage and Casualties after an Earthquake

The relationship between building damage patterns and human casualties in Nishinomiya City – one of the most heavily damaged cities in the 1995 Hanshin-Awaji Earthquake Disaster – was investigated using photographs of damaged buildings. First, the photographs of buildings in which casualties occurred were identified, and the building damage patterns were judged based on the photographs considering the existence of survival space. Then the relationship between the building damage pattern and casualty occurrence, and the characteristics of casualty distribution, were investigated. The main findings were as follows: Most casualties occurred in relatively old two-story wooden buildings in which the ground floor completely collapsed without survival space; casualties occurred at all building damage levels including ``no damage', and it can be seen that building damage is the major, but not the sole cause, of casualties in an earthquake; in Nishinomiya City, the regional distributions of casualties due to the collapse of buildings that left no survival space is similar to that of casualties due to other types of building damage.     

Water absorption process effect on strength of Ayazini tuff,such as the uniaxial compressive strength (UCS), flexural strength and freeze and thaw effect

Tuffs have been used as a construction material possibly since ancient times. In Afyonkarahisar, Turkey, there are numerous buildings constructed by tuff. Tuff has been a local construction material, during the Roman, Seljuk and Ottoman periods. Even though tuffs have relatively low durability and low strength values compared to marble, etc., they have survived with no major deterioration failures on many historical buildings. It has also been preferred because of its high porous texture, lightweight and easy shaping and process properties in the building sector. Naturally, it would be easily affected by water and humidity because of its porous structure. However, having this kind of structure leads to poor durability properties due to keeping water in it. The main objective of this study was to evaluate the physical and mechanical properties of the tuff quarried from the region and possible water effect, which may lead to degradation of its strength and durability of the material, thereby shortening the life span of the building structure used. Samples, which were tested after exposing to water and the freeze and thaw effects, were measured at a certain time. In this study, uniaxial compressive strength and flexural strength tests were conducted on test samples. The test results indicate that water may deteriorate the tuff’s strength properties and durability of the materials in due time.     

A quantitative weathering classification system for yellow travertines

Weathering can cause adverse effects on the physico-mechanical properties of rocks. Although the processes and outcomes of weathering have been investigated for many rock types, the travertine weathering was not paid enough attention as much as the others. However, the unfavorable effects of weathering may arise rapidly due to travertine’s calcium carbonate composition and highly porous texture. Travertine is an important rock type in building stone market and is generally preferred as an exterior façade material. This rock type was also used in many historical buildings and sculptures in the past, and the signs of extensive weathering can be recognized on some of these travertine-made structures. In this study, it was aimed to characterize the effect of weathering on travertine’s structural properties. The yellow travertine from Eskipazar (Karabuk, Turkey) was selected as the study material and the samples with different weathering degrees were collected from site. The chemical, physical and mechanical properties of those samples were determined in laboratory. The physico-mechanical variations with progressive weathering grades were statistically evaluated and a weathering classification based on a rating system was proposed for yellow travertine in rock material scale. The newly developed system may assist in characterizing the degree of weathering for historical structures built by yellow travertine. Additionally, the classification may also guide to further researches on the weathering of different types of travertine.     

Ocean/atmosphere interaction and Malthusian catastrophes on the northern fringe of the Asian summer monsoon region in China, 1368–1911

How and to what extent are human societies affected by climate change? There has been a growing body of research using big historical data and statistical analyses to provide scientific answers to this inter-disciplinary research question. However, quantitative analysis measuring the historical demographic impact of ocean/atmosphere interaction is still scanty. Here we use 544 years (1368–1911) of historical records to trace the demographic impact brought about by ocean/atmosphere interaction in Shaanxi, located on the northern fringe of the Asian summer monsoon region in China. Our results show that: (1) North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO) caused Malthusian catastrophes mainly through drought at the inter-annual scale; (2) drought reinforced the synchrony of various Malthusian catastrophes at the inter-annual to multi-decadal scale; and (3) the unusual cycles of NAO drove drought and various Malthusian catastrophes in the cold 1550–1730 period at the multi-decadal scale. This study represents a pioneering attempt to quantitatively assess the demographic impact caused by the ocean/atmosphere in historical China. Our findings may help to conceptualise the climate–human nexus in those ecologically marginal regions that are impacted by ocean/atmosphere interaction, and to explain the synchrony of social crisis in Eurasia in the 17th century.     

“Internet+” approach to mapping exposure and seismic vulnerability of buildings in a context of rapid socioeconomic growth: a case study in Tangshan,China

This paper presents the development of an “Internet+” approach to mapping exposure and seismic vulnerability of buildings in a context of rapid socioeconomic growth. This approach is a combination of the following interdependent components: (1) extraction of footprint areas of a large number of buildings from high-resolution Google Earth images; (2) estimation of floor numbers of these buildings with an integrated use of high-resolution Google Earth images, Tencent/Baidu Street Views, crowdsourcing data, and associated building-relevant local knowledge; and (3) identification of structural types of these buildings by a combined use of crowdsourcing data and associated building-relevant local knowledge. The efficacy of this “Internet+” approach was demonstrated through an application in Tangshan, China. Field-based verification indicated that the overall mean absolute percentage error of the proposed “Internet+” approach in assessing the total floor area of the addressed buildings was 4.64 %. The verification also showed that the overall consistency between the estimated structural types using the proposed approach and the actual structural types of the buildings with structural type uncertainties could reach 97.54 %, with a kappa coefficient of 0.94. Because of its good accuracy, noteworthy speed, substantial labor savings, negligible cost and distinctive capability in covering large areas in near real time, this “Internet+” approach might have promising prospects in actual seismic loss risk reduction challenges.

     

Empirical seismic vulnerability,deterministic risk and monetary loss assessment in Fira (Santorini,Greece)

A deterministic seismic risk and monetary loss model is presented for the capital of Santorini volcanic Island, the town of Fira, on a building block scale. A local seismic source of M5.6 inferred from a recent volcano unrest in 2011–2012, detailed seismic vulnerability of 435 buildings and site conditions deduced from free-field ambient noise measurements were combined toward assessing the EMS-98 damage grade and its probability to occur. The seismic scenario yielded no damage or slight damage for 84% of the buildings, 16% of the constructions are expected to present moderate-to-heavy damage, while the economic loss amounts to 4 million euros. Although the model predicts low damage and direct economic loss, interaction with the touristic business activities might produce cascade side effects for the economy of the island and consequently Greece’s GDP, an important part of which emanates from Santorini.