Analysis of Roof Collapse Cases Caused by Snow Loads in Russia (2001–2021)

Cases of building decay and structural damage caused by the impact of snow loads are registered every year throughout the world. Such destruction not only results in property loss, but also leads to human losses. A database on 266 cases of roof collapse caused by snow loads in Russia for the period from 2001 to 2021 was collated for this study. The data were analyzed by date and place of collapse, building data, and number of victims. The analysis showed that civilian buildings are the most vulnerable, comprising 78% of the total number of collapses, followed by industrial buildings with 15% and agricultural buildings with only 7%. The relationships between roof shape, roofing material, number of floors, and type of collapsed building were determined. The data processing results showed that low-rise residential buildings (one to two floors) with a gable roof covered with fiber cement should be considered the most vulnerable. A linear relationship was revealed between a collapse area of more than 150 m2 and the cumulative number of collapse cases. The obtained results have practical application for rating building vulnerability to natural hazards and assessing the risk of emergencies associated with snow loads.

Evaluation of Building Vulnerability to Earthquake Using Rapid Visual Screening (RVS) Method

Indonesia is one of the countries prone to earthquakes. One of the earthquake disasters that occurred several years ago hit Palu and Donggala on September 28, 2018. It caused severe damage to infrastructure. Therefore, it is necessary to evaluate buildings vulnerable to earthquakes as a form of prevention. One of the buildings in Jember, the dr. Soebandi hospital, experienced cracks in the walls during an earthquake measuring 6.0 on the Richter scale in Nusa Dua Bali on July 16, 2019. This study carried out the risk assessment of the vulnerability of buildings to earthquakes using the Rapid Visual Screening (RVS) method from FEMA P-154. RVS is a method to identify a building that is potentially vulnerable to earthquake hazards based on visual observations from the exterior and interior of the building. The results of the evaluation using the RVS method showed that the dr. Soebandi hospital is categorized as safe and not prone to earthquakes, with a potential vulnerability percentage of 0.0126%. Based on these results, the building does not require special treatment to anticipate earthquakes; however, maintaining the occupants' safety and extending the building's life requires routine maintenance.

Assessment of Seismic Building Vulnerability Using Rapid Visual Screening Method through Web-Based Application for Malaysia

Rapid visual screening is a quick and simple approach often used by researchers to estimate the seismic vulnerability of buildings in an area. In this study, preliminary seismic vulnerability assessment of 500 buildings situated at Northern and Eastern George Town, Malaysia, was carried out by utilizing a modified FEMA-154 (2002) method that suits Malaysian conditions. Data were collected from online sources via Google Maps and Google Earth instead of traditional surveying data collection through street screening. The seismic assessment analysis of this study was based on the RVS performance score and the damage state classification for each building typology. This approach generates, for each building, a final performance score based on governing parameters such as structural resisting system, height, structural irregularities, building age, and soil type. The findings revealed the immediate need for effective seismic mitigation strategies, as 90% of the studied buildings required a further detailed analyses to pinpoint their exact seismic vulnerability performance. Most of the surveyed buildings were predicted to experience moderate-to-substantial damage, with 220 out of 500 being classed as damage state 2 (D2) and damage state 3 (D3). A GIS map, “RVS Malaysian Form-George Town Area”, was generated via ArcGIS and shared with the public to provide vital information for further research.

A Quantitative Approach to Assess Seismic Vulnerability of Touristic Accommodations: Case Study in Montreal, Canada

In many places of the world, the interruption of touristic activities in the aftermath of a catastrophic earthquake is often neglected in the evaluation of seismic risks; however, these activities can account for a significant proportion of short-term and long-term economic impacts for these regions. In the last decade, several rapid visual screening techniques have been developed to define the typology of buildings and to estimate their seismic vulnerability and potential for damage. We adapted the existing screening procedures that have been developed for generic buildings to specific circumstances that are most common for tourist accommodations. The proposed approach considered six criteria related to structural and nonstructural elements of buildings, as well as local soil conditions. A score was assigned to each criterion as a function of the capacity of the elements to resist ground shaking. A vulnerability index in four levels of building vulnerability was developed combining the scores of the six criteria. The approach was tested in a pilot area of Montreal to a set of 70 typical buildings grouped in four categories based on their accommodation capacity. In Montreal, tourism is an important source of income for the city where 351,000 room-nights were booked with total stay expenditures of CAD 4.9 billion in 2019. The results indicated potential significant disruptions in activities related to tourism; 46% of the buildings investigated have a high to very high vulnerability index. Among them, 4/5 are located in the old city and 1/5 in the downtown area of the pilot zone.

An Indicator-Based Approach for Micro-Scale Assessment of Physical Flood Vulnerability of Individual Buildings

The current trends of floods event in many countries are alarming. Hence, managing flood and the associated risk are crucial in order to reduce the loss and to be well prepared for the combined impact of urbanization and climate changes. The best approach to manage flood activities is a risk-based approach, where the vulnerability of elements at risk is reduced to a minimum. There is a significant number of studies that use an indicator-based approach for flood vulnerability assessment with focus on the macro-scale. However, this paper assesses physical flood vulnerability of buildings at micro-scale using an indicator-based method in Kota Bharu, Malaysia. The region is one of the most flood affected regions in Malaysia. Micro-scale vulnerability assessment considers damages for individual buildings at risk, rather than in aggraded manner. In this study, the methodology adopted involve the use of 1D-2D SOBEK flood modelling, the selection and weightage of indicators, development of spatial based building index and, production of building vulnerability maps. The findings demonstrate the physical pattern of flood vulnerability of buildings at a micro-scale. The approach can assist in flood management planning and risk mitigation at a local scale

Earthquake Vulnerability Mapping using Binary Comparison Matrix and Analytical Hierarchical Process (AHP) in Lalmatia, Dhaka

From the historical records, geological evident and recent trends in earthquake, it is evident that Bangladesh is in a high-risk zone of earthquake hazard. The recent results of the CDMP, if a huge earthquake greater or equal to seven magnitude happened in this country, would lead to a serious human tragedy due to the defective structure. In Lalmatia, Dhaka study area there are various types of structures as like as RCC, masonry, semi-pucca etc. and the area has different old and newly filled soil development. This study considered the characteristics of RCC building elements and their behaviors to assess the risk against earthquake vulnerability in Lalmatia using the Turkish method. Next building vulnerability from Turkish Method used as one total vulnerability factor. In the method of this research, a pair wise comparison matrix for a numerical relationship between two elements and the Analytical Hierarchical Process (AHP) model has been applied to decide in weight and to get rank of the vulnerability factors. By weighted sum vector among the six factors and calculating vulnerability index (VI), the overall vulnerability were identified in Lalmatia. Using Geographic Information System (GIS) and defining an ordinal scale of calculated result, the vulnerability status of single buildings of the study area is presented here. This research tells that 8.23% buildings are highly vulnerable and 14.24% buildings are moderately vulnerable to earthquake. About 77.53% buildings are less vulnerable. As the study area is in a major urban center (Dhaka City), the scenario of unplanned urbanization increases the overall vulnerability to higher scale.

Reliability based formulation of building vulnerability to debris flow impacts

Physical building vulnerability to debris flows is defined as the potential damage degree of buildings for a given debris-flow intensity. In this paper, the physical characteristics on both debris flow intensity and building response are considered. Uncertainties in building capacity and debris flow intensity are explicitly quantified to evaluate the damage probability of a typical reinforced concrete building subject to debris flow impact. Four damage states with clear failure mechanisms are defined using multi-source information from field observations, numerical simulation and expert experience. Two series of fragility models have been proposed based on practical debris-flow impact pressure models. Several debris flow intensity measures are investigated. A better indication can be provided using the intensity measure that represents specific failure mechanism, for example, impact force (hv2) for force-dominated failures or overturning moment (h2v2) for moment dominated failures, where h and v are debris flow depth and velocity, respectively. The corresponding fragility surfaces best express the potential building damage. The intensity thresholds in the proposed fragility curves are consistent with those in empirical vulnerability curves. The methodology presented in this paper promotes the vulnerability assessment using physics based modeling, leading to a more reliable evaluation of building damage caused by debris flows.

Earthquake Catastrophe Risk Modeling, Application to the Insurance Industry: Unknowns and Possible Sources of Bias in Pricing

Mathematical risk assessment models based on empirical data and supported by the principles of physics and engineering have been used in the insurance industry for more than three decades to support informed decisions for a wide variety of purposes, including insurance and reinsurance pricing. To supplement scarce data from historical events, these models provide loss estimates caused to portfolios of structures by simulated but realistic scenarios of future events with estimated annual rates of occurrence. The reliability of these estimates has evolved steadily from those based on the rather simplistic and, in many aspects, semi-deterministic approaches adopted in the very early days to those of the more recent models underpinned by a larger wealth of data and fully probabilistic methodologies. Despite the unquestionable progress, several modeling decisions and techniques still routinely adopted in commercial models warrant more careful scrutiny because of their potential to cause biased results. In this chapter we will address two such cases that pertain to the risk assessment for earthquakes. With the help of some illustrative but simple applications we will first motivate our concerns with the current state of practice in modeling earthquake occurrence and building vulnerability for portfolio risk assessment. We will then provide recommendations for moving towards a more comprehensive, and arguably superior, approach to earthquake risk modeling that capitalizes on the progress recently made in risk assessment of single buildings. In addition to these two upgrades, which in our opinion are ready for implementation in commercial models, we will also describe an enhancement in ground motion prediction that will certainly be considered in the models of tomorrow but is not yet ready for primetime. These changes are implemented in example applications that highlight their importance for portfolio risk assessment. Special consideration will be given to the potential bias in the Average Annual Loss estimates, which constitutes the foundation of insurance and reinsurance policies’ pricing, that may result from the application of the traditional approaches.