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Purpose: Studies showed that construction digitalisation could prevent or mitigate accidents rate on sites. Digitalisation applications may prevent or mitigate building project collapse (BPC) but with some encumbrances, especially in developing countries. There is a paucity of research on digital technologies application to prevent or mitigate BPC in Nigeria. Thus, the research aims to explore the perceived barriers that may hinder digital technologies from preventing or mitigating building collapse and recommend measures to improve technology applications during development. Design/methodology/approach: The study is exploratory because of the unexplored approach. The researchers collected data from knowledgeable participants in digitalisation and building collapse in Nigeria. The research employed a phenomenology approach and analysed collected data via a thematic approach. The study achieved saturation at the 29th interviewee. Findings: Findings show that lax construction digitalisation implementation, absence of regulatory framework, lax policy, unsafe fieldworkers' behaviours, absence of basic infrastructure, government attitude, hesitation to implement and high technology budget, especially in developing countries, are threats to curbing building collapse menace via digitalisation. The study identified technologies relevant to preventing or mitigating building collapse. Also, it proffered measures to prevent or mitigate building collapse via improved digital technology applications during development. Originality/value: This research contributes to the construction digitalisation literature, especially in developing countries, and investigates the perceived barriers that may hinder digital technologies usage in preventing or mitigating building collapse in Nigeria. [ABSTRACT FROM AUTHOR]

Large-scale floods induced by dam failures could cause significant structural damage to buildings and massive loss of life. The coupling effect of large-scale flood spread and building collapse has complex impacts on the entire flow field, affecting flood risk assessment and building vulnerability evaluation. In this paper, a dynamic elevation change model designed to seamlessly interface with a structural vulnerability assessment model to investigate the interaction effect between floods and buildings is presented. The efficiency of the framework was validated by reconstructing the Gleno Dam-Break flood in Italy. Subsequently, a hydrodynamic model of the Jinsha-Yalong River that considers dynamic building collapse was established. The proposed model was compared with two traditional building treatment approaches and one that ignored the buildings. The results show that the interaction between the flood and buildings decreases the low-velocity area (below 1 m/s) by 7.44%–9.56% while increasing the high velocity area (above 4 m/s) by 10.71%–11.96%. Traditional and neglecting building treatments provide preliminary insights into densely built areas, and the latter could be an alternative for simplification because it can represent the worst-case scenario. Building collapse in response to large-scale floods typically occurs in four stages: flood spread, rapid expansion, gradual expansion, and flood recession. This analysis offers novel perspectives on flood prediction and simulations where the floodplain may contain buildings. This method could be useful for assessing structural vulnerability associated with large building stocks and developing flood mitigation strategies in densely populated areas. [ABSTRACT FROM AUTHOR]

This research analyzed the mechanical properties of reinforcing steel bars used in Nigeria and compared them to four different standards (AISI 1018, ASTM A706, BS4449, and NST-65-Mn). This was done as a result of frequent building collapses in Nigeria, which has revealed the knowledge gap between what the designers expect and the true mechanical properties of the products they typically receive from manufacturers. Related literature from published articles was collected and analyzed based on the mechanical properties of locally produced and imported steels. Results showed that the tensile strength, yield strength, hardness, percentage elongation, and percentage carbon composition of most products met and exceeded the requirements of AISI 1018, ASTM A706, BS4449, and Nst-65-Mn when compared, while some fell below what these standards required. Federated Steel Mills Limited, Ogun State, has the highest tensile stress value at 799.49 MPa, followed by Real Steel Reinforcing Pty Limited, Auckland, New Zealand, at 726.34 MPa, and Landcraft Industries Limited, Ikorudu, Lagos, at 708.3 MPa, according to a yield and tensile strengths analysis of 16 mm steel bars produced locally and imported. The lowest tensile strengths ever reported are 410 MPa for African Steel Nig. Limited, Ikorodu, Lagos, and 538.51 MPa for steel imported from Brazil. It is hoped that the data from this study will bridge the knowledge gap between the team players in this field, thus preventing catastrophe.

Abstract The construction industry in Nigeria faces critical challenges due to frequent building collapses, highlighting the necessity for robust Quality Management Systems (QMS). This study investigates the current state of QMS adoption and its effectiveness in mitigating building failures. Despite the recognised importance of QMS, the industry shows a low adoption rate, with only 34.8% of firms holding ISO certification and 60.9% lacking formal QMS frameworks. A significant barrier identified is insufficient top management support, impacting 71.4% of the companies surveyed. The study employs a mixed-methods approach, including a comprehensive literature review and a survey of 22 industry stakeholders across major Nigerian cities. This methodology allows for a detailed examination of QMS practices, highlighting the critical role of management commitment, communication, and training in enhancing quality outcomes. The research fills a gap by providing a holistic analysis of QMS issues across different regions, which have been previously understudied. The findings underscore the necessity for enhanced regulatory frameworks and standardised practices to ensure consistent quality management. The study contributes to the international discourse on construction quality by emphasising systemic improvements rather than merely technical fixes. It calls for further research into region-specific challenges and broader adoption of formal QMS practices to improve safety and reliability in Nigeria's construction sector.

Computer simulation is increasingly being used by emergency planners as a tool to improve disaster response given that it can model real-world scenarios, such as earthquakes. Although there has been an increase in simulation research focused on disaster response, much of this literature is from disparate fields and across disaster scenarios. To bridge this gap, this paper surveys simulation-based models for postearthquake response from the year 2000 onward. Advantages of simulation over closed-form statistical models are discussed. Three main subproblems in postearthquake response models are explored: (1) service distribution (e.g., food, water), (2) infrastructure restoration (at the building and transportation system level), and (3) emergency healthcare provision (i.e., casualty treatment). Additionally, the underlying simulation-optimization model in its canonical form and numerical results from case studies are presented to illustrate the nature and size of the problems encountered in the real world. Thereafter, gaps in the literature are identified keeping in mind the objectives of FEMA's recent strategic plan, which focuses largely on equity and resilience. This paper revealed key misalignments between policy priorities and existing literature—specifically, that there is a gap in equity-based simulation modeling. [ABSTRACT FROM AUTHOR]

Abstract Estimating potential casualties from a significant earthquake and tsunami event is crucial to enhance disaster preparedness and response. Although various approaches exist to assess potential casualties, few studies have made direct comparisons between them. The present study aimed to clarify the differences in the estimation of casualties between an agent-based model (ABM), which can capture detailed evacuation behavior but demands significant computational resources, and a simplified approach at less computational cost by assuming that evacuees would move along a straight line from their initial location to the closest evacuation destination. These different approaches were applied to three coastal cities in Japan—Mihama, Kushimoto, and Shingu in Wakayama Prefecture—revealing significant differences in the estimated results between the ABM and the simplified approach. Notably, when the effects of building collapse due to an earthquake were considered, the mortality rates estimated by the ABM were higher than those estimated by the simplified approach in the three cities. There were also significant differences in the spatial distribution of the estimated mortality rates between the ABM and the simplified approach. The findings suggest that while the simplified approach can yield results more quickly, casualty estimates derived from such models should be interpreted with caution.

Estimating potential casualties from a significant earthquake and tsunami event is crucial to enhance disaster preparedness and response. Although various approaches exist to assess potential casualties, few studies have made direct comparisons between them. The present study aimed to clarify the differences in the estimation of casualties between an agent-based model (ABM), which can capture detailed evacuation behavior but demands significant computational resources, and a simplified approach at less computational cost by assuming that evacuees would move along a straight line from their initial location to the closest evacuation destination. These different approaches were applied to three coastal cities in Japan—Mihama, Kushimoto, and Shingu in Wakayama Prefecture—revealing significant differences in the estimated results between the ABM and the simplified approach. Notably, when the effects of building collapse due to an earthquake were considered, the mortality rates estimated by the ABM were higher than those estimated by the simplified approach in the three cities. There were also significant differences in the spatial distribution of the estimated mortality rates between the ABM and the simplified approach. The findings suggest that while the simplified approach can yield results more quickly, casualty estimates derived from such models should be interpreted with caution. [ABSTRACT FROM AUTHOR]

In any industry related to the construction of buildings and structures we have heard about the need to assess the technical condition of various objects to assess and analyze the risks associated with the possible collapse of buildings (structures), loss of life and high costs to eliminate these consequences. Since many objects fail over time, and in general to determine the wear and tear and the possible term of further safe operation, it is necessary to conduct a technical survey. The article describes the principle of operation of thermal imaging devices for determining the reliability of building structures in residential premises, and also raises problems, the solution of which can simplify the use of thermal imaging devices in the inspection of buildings and structures and reduce the economic costs of damage compensation in case of timely detection and elimination of any defects. [ABSTRACT FROM AUTHOR]

Building construction collapse in Nigeria has become a subject of international concern in recent times due to numerous lives and properties being wasted yearly. This study presents a brief statistical report of building collapse in Nigeria from 2000–2021, using Lagos State as a case study and conducts a comparative analysis using five supervised machine learning algorithms, namely Robust Linear Model (RLM), Support Vector Machine (SVM), K Nearest Neigbours (KNN), Random Forest (RF) and Decision Tree (DT) for predicting the rate of casualty from building collapse in Lagos Nigeria. Feature importance was performed to determine the most relevant factors that causes building construction collapse casualty. The result shows that the Support Vector Machine (SVM) algorithm has the best forecasting performance among the other algorithms considered. Feature importance analysis, using the SVM model ranked the factors affecting building construction collapse in order of relevance and 'location' is considered the most relevant factor contributing to building collapse casualty in Nigeria. Results from this study are important for policy makers and the study recommends that proper onsite geo-technical inspection should be done on site locations before commencement of building constructions in Nigeria. [ABSTRACT FROM AUTHOR]

Landslide has become the primary focus in slope engineering as the case increases. Most landslides are resulted from an unknown confluence, and most occur on slopes created by humanity. Highland Towers were built between 1976 and 1979, and its occupants were primarily first and middle-class people. There is a steep hill behind the three blocks. The main draws here are the natural scenery and panoramic vista of Kuala Lumpur. This case study investigates what factors led to Block 1, Highland Towers condominium’s collapse on 11th December 1993 at 1.35 p.m. using reliability analysis approaches and human fault impact factors. The Block 1 collapse is caused by an unstable pile foundation. The engineers incorrectly estimated the horizontal load design, causing surcharge loads to be created by the downhill forward movement when the rotating retrogressive slide happens. However, several precautions may be taken to protect the building structures from landslide. It is common knowledge that structural reliability analysis yields failure probabilities that are not considered for human faults. Inadequate drainage, collapse of retaining wall, and rail piling foundation are all plausible explanations for this landslide initiation. Thus, combining structural and human reliability analysis are recommended to mitigate landslide, including slope hazards.

Landslide has become the primary focus in slope engineering as the case increases. Most landslides are resulted from an unknown confluence, and most occur on slopes created by humanity. Highland Towers were built between 1976 and 1979, and its occupants were primarily first and middle-class people. There is a steep hill behind the three blocks. The main draws here are the natural scenery and panoramic vista of Kuala Lumpur. This case study investigates what factors led to Block 1, Highland Towers condominium's collapse on 11th December 1993 at 1.35 p.m. using reliability analysis approaches and human fault impact factors. The Block 1 collapse is caused by an unstable pile foundation. The engineers incorrectly estimated the horizontal load design, causing surcharge loads to be created by the downhill forward movement when the rotating retrogressive slide happens. However, several precautions may be taken to protect the building structures from landslide. It is common knowledge that structural reliability analysis yields failure probabilities that are not considered for human faults. Inadequate drainage, collapse of retaining wall, and rail piling foundation are all plausible explanations for this landslide initiation. Thus, combining structural and human reliability analysis are recommended to mitigate landslide, including slope hazards. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to investigate the factors influencing the responsiveness of construction participants to building collapse in the Nigerian construction industry. There has been a general type of response to incessant menace of building collapse among construction participants which is, playing the blame game. This is worrisome considering its attendant psychological effect on the affected persons and cost implications to the industry at large. Design/methodology/approach – Literature review conducted identified forty-nine (49) factors that can influence the responsiveness of construction participants to building collapse, which were employed to design a questionnaire survey. Data collected were analysed using descriptive statistics, mean score, Kruskal–Wallis test of ANOVA and multivariate techniques such as factor analysis. Findings – The descriptive and empirical analysis showed disparity of ranking of the 49 factors among the groups studied. There was statistically significant difference (ρ < 0.05) in 35 representing 71.4% of the factors influencing the responsiveness of participants in the construction industry to building collapse while the remaining 28.6% was not significantly different. Therefore, irrespective of the individuality of response from each group of construction participants, they still demonstrated a reasonable level of agreement in their responses to the factors influencing the responsiveness. Among the significant factors based on the mean score rankings are quality of materials, availability of experienced professionals, adequate enforcement of building code, design and specifications changes, financial capability of clients and budget allocation for building projects. Through factor analysis, the study categorized the forty-nine factors influencing the responsiveness of participants in the construction industry into six general factors. The factors are: client related; project procurement related; economic management related; ethical values related; construction management related and policy management related. Practical implications – The investigation into the factors influencing the responsiveness of participants is with a view to mitigating continuous occurrences of building collapse in Lagos State, and Nigeria as a whole. This is a very useful information on the roles and duties of all construction professionals and other stakeholders in the construction industry. Also, stakeholders in the academia can carry out a review of the curriculum for tertiary institutions based on the information on factors influencing responsiveness of construction participants. Originality/value – The study was able to categorise all the forty-nine factors into six basic groups using the factor analysis, and this could be used to develop measures for mitigating occurrences of building collapse. hence, it has successfully provided insightful knowledge base regarding the basic factors influencing the responsiveness of participants in the construction industry to building collapse, especially in Lagos State, Nigeria.

The tragedy of the sudden collapse of the 2021 Champlain Towers condominium building in Surfside, Florida raises issues of civil liability and throws into doubt the sustainability of the current model of condominium association governance. This case study evaluates the potential causes of the collapse, and reactions of various parties including the consulting engineering company, city regulators, condominium association board, outside property manager, original builder, and unit owners themselves. By conducting a comprehensive literature review, this paper is aimed to find out the reasons, frequency and liability of building collapse, as well as the roles condominium governance, financial modeling, poverty, or statutory language play in the tragedy. Some advice for further improvements to improve board sustainability is given to original developers, contractors, engineers, and insurance carriers. The current model of condominium management has blind spots and appears to be unsustainable. One suggestion to fix the problem is to require that insurance be obtained to insure the liability of condominium associations, including for this type of tragedy. That would create a financial risk/incentive for the insurance company to ensure adequate management and upkeep. The insurance company should also set board member expertise qualifications, insurance premiums, need for outside expertise, required inspections/maintenance, and replacement reserves that are required to maintain that coverage.

The Czech Congregation of Dominican Sisters was founded in Řepčín near Olomouc in 1889. The mission of the congregation was primarily to educate and bring up young girls in the spirit of St. Dominic. As the congregation was increasingly popular with the Czech population, the nuns had to rebuild and enlarge their monastery several times. The last reconstruction planned for autumn 1930 involved a new three‑storey building that was supposed to be situated next to the monastery. The Olomouc builder Jan Valihrach undertook the construction, however, shortly before its completion the building suddenly collapsed. The builder Valihrach, along with the designer Josef Derrich, was accused of the collapse. While Valihrach was found guilty of the collapse of the building, Derrich’s prosecution was stopped due to his death. Valihrach denied his guilt, however, and subsequently brought a lawsuit against the Dominican Convention of Řepčín. He demanded a payment of the agreed sum for the building and also a payment of other debts from the past that had not been paid by the nuns. The nuns counter-sued and demanded compensation from Valihrach for damages caused by the collapse of the building. After examining the evidence and questioning the witnesses of both involved parties the courts concluded that both the builder Valihrach and the deceased designer Derrich were guilty of the collapse. In the case of the designer Derrich, the court recognized him as the implicit representative of the Řepčín convent of Dominican nuns at the construction. The judges ruled that the Dominican nuns should pay Valihrach just half of the requested compensation, which amounted to 333,300 crowns. [ABSTRACT FROM AUTHOR]

Fire can damage structures severely and even cause the building collapse. Structural and fire engineers must carry out a comprehensive forensic investigation of major structural failures in the same rigorous and meticulous manner the airline industry investigates air crashes. The forensic assessment should identify the cause, fire spread scenario, fire behaviour patterns from its growth to decay, de-compartmentation, the performance of fire protection systems, and firefighting management. Using the available tools and data, the current paper proposes a methodology to reconstruct the fire for the forensic assessment of tall buildings. This is done by first organising observed data into a coherent timeline and presenting the actual fire spread obtained from the visual evidence. The total fire spread within the building is estimated based on fire dynamics principles and observed fire scenes that can be verified with a calibrated CFD model. The collapse of the Plasco Building is assessed by employing the proposed framework. The rise in construction of the tall buildings increases the risk of the occupants’ safety from the fire induced structural failure or collapse. The framework presented in this paper can guide engineers to improve the building resilience designs and reduce the fire accidents related risks.

Every year incidents of building collapse claim many lives and cause enormous financial losses around the world, which are often blamed on low‐quality materials, non‐compliance with standards, lack of oversight, and failure to enforce building codes. Here, we highlight the role of land subsidence in triggering unprecedented collapses in the city of Lagos, Nigeria, which has reported over 200 casualties during 152 building failures since 2005. We used acquisitions from radar satellites for 2018–2021 and provided data that link subsidence to foundation damage and high building failure risk in the region. We estimate that an area of 5–81 km2 and 255–4,000 buildings are exposed to a high to very high risk of collapse for short‐term (10 years) to long‐term (75 years) periods. Differential land subsidence can trigger building collapse, and the data presented here will enable authorities to create adequate building codes and standards and devise mitigation strategies. Plain Language Summary: Low‐quality materials, non‐compliance with standards, a lack of oversight, and failure to enforce construction codes are frequently cited as causes of the annual global increase in building collapses that kill countless lives and result in tremendous financial losses. In this article, we focus on the impact that land subsidence plays in causing building collapses in Lagos, Nigeria. We employed radar satellite acquisitions from 2018 to 2021 to present evidence linking subsidence with foundation damage and a significant risk of building failure in the area. We calculate that in the future, between 5 and 81 km2 and 255–4,000 buildings are at a high to very high risk of collapsing. Key Points: Major parts of the city of Lagos are subsiding at rates of more than 4 mm/yrOur analysis suggests a causal relationship between incidences of building collapse and differential subsidence in LagosBy 2053, a total area of 45 km2 and approximately 2,200 buildings will be exposed to a high to very high risk of collapse [ABSTRACT FROM AUTHOR]

Abstract Every year incidents of building collapse claim many lives and cause enormous financial losses around the world, which are often blamed on low‐quality materials, non‐compliance with standards, lack of oversight, and failure to enforce building codes. Here, we highlight the role of land subsidence in triggering unprecedented collapses in the city of Lagos, Nigeria, which has reported over 200 casualties during 152 building failures since 2005. We used acquisitions from radar satellites for 2018–2021 and provided data that link subsidence to foundation damage and high building failure risk in the region. We estimate that an area of 5–81 km2 and 255–4,000 buildings are exposed to a high to very high risk of collapse for short‐term (10 years) to long‐term (75 years) periods. Differential land subsidence can trigger building collapse, and the data presented here will enable authorities to create adequate building codes and standards and devise mitigation strategies.

Objective: The objective of this study was to determine whether coordination of prehospital emergency health services and Disaster and Emergency Management Presidency (DEMP) and being prepared for disasters, such as building collapses, allow quick evaluation and fast intervention. Methods: The information flow, hierarchy, treatment, and rehabilitation processes, and rescue organization and planning during the rescue attempt for 35 people who needed help due to this building collapse were reviewed. Results: Of the 43 people who lived in this 8-story building, 35 were inside the building during the collapse; 40% of them were assessed as injured and 60% as exitus. Almost two-thirds (64.3%) of the injured individuals who were rescued were women. The mean duration until rescue was 330 (57.0-512.0) min. Conclusions: Leading and important factors that can increase the success rate in search and rescue interventions are informing official authorities as first early warning by individuals who can clearly define the situation, early security measures by security forces arriving before the health and search-rescue teams, accurate identification of estimated numbers of injured victims, and identifying and informing appropriate hospitals which victims rescued from the debris will be transferred to there. [ABSTRACT FROM AUTHOR]

The persistent increase in the occurrence of building collapse with attendant loss of lives in recent years has become a source of national concern in Nigeria. Hence, there is a need to strategically address gaps in proactive and reactive measures directed at preventing the occurrence of building collapse. This study explored how built environment professionals in government agencies, public and private institutions conceive the causes of building collapse, and the disaster risk reduction measures put in place by the state government to prevent and respond to the incidence of building collapse in Lagos state. The purposive snowball sampling technique was adopted to select 42 respondents for in‐depth interviews. The findings revealed that building collapse is a common phenomenon in the study area and is primarily caused by institutional failure and human factors. The research further established that most collapsed buildings were old residential buildings. It was also discovered that the disaster risk reduction strategies put in place to curb the occurrence of building collapse were not holistic and effective. The study recommended continuous sensitization of building developers and provision of modern facilities such as drones and global positioning systems by the government for effective monitoring of building development in the state. [ABSTRACT FROM AUTHOR]

Featured Application: The safety chairs presented in this paper, provided with shock-absorber and retaining systems, are aimed at equipping seismic shelters developed to protect people's lives in case of building collapse caused by an earthquake. Project SHELTER, Structural Hyper-resisting Element for Life-Threatening Earthquake Risk, aims at developing a strong and stiff functional unit to protect its occupants in case of severe earthquakes that lead to structural collapse. In case of collapse, these units will suffer impacts, particularly if they are installed in upper floors. To avoid severe injuries or death of occupants caused by collapse, safety chairs were designed, provided with shock-absorber systems and auxiliary retaining devices, to keep the occupants properly seated and safe. Three downfall scenarios were evaluated, consisting of vertical and tilted positions. A comprehensive numerical model to represent the human body was developed, mainly focused on chest behaviour and considering the anatomic limits of the vertebral spine. The mechanical ability of the safety chair to ensure the occupants' safety was evaluated under these harsh conditions. Experimental downfall-and-impact tests will later be performed on shelter units, with crash-test dummies seated on the safety chairs for final validation. [ABSTRACT FROM AUTHOR]

The mishap of building collapse does not sound strange again in many sub-Saharan cities especially Nigeria due to the frequency of its occurrence, and architects are most vulnerable to blame because of their leadership position in building delivery. Evidence in literature has suggested a critical appraisal of built environment professionals' role to tackle the menace. However, the consequence of the role of architects as prime consultants hasn't been adequately investigated. Using a systematic review of literature for reported cases of building collapse in Nigeria between 2009 and 2019, the paper examines the causes of building collapse and enumerated specific areas members of the architecture profession in the building industry are implicated. The result reveals that the major causes of building collapse are the use of substandard materials, structural defects, and the use of incompetent personnel indicating a lapse in leadership and supervisory function. Although from direct observation, the study highlights deontology as the bane of building collapse in Nigeria and recommends among others that: Standard Organization of Nigeria (SON) should ensure that only certified building materials are allowed in the market; soil tests, environmental impact analysis, and structural analysis should be mandatory as well as proper supervision of construction works by competent professionals with strict law enforcement. [ABSTRACT FROM AUTHOR]

One of the pressing issues of forensic activity is the absence of an approved list of the necessary and sufficient documentation to conduct a full and comprehensive study for every type and kind of forensic examination, including construction forensics. This makes the tasks put before an expert more challenging, expands the duration of the examination, and sometimes it even leads to the additional and re-examinations. The resolution of this problem would make the work easier for investigators and experts streamlining their activity at the early stages of investigations. The author identifies the types of input data for forensic construction and technical examinations of destroyed buildings. The article provides a list of documentations regulating the research process in cases of building collapse; limits for the use of equipment and tools are also covered.

The application of specialized natural hazard mapping is an absolute necessity for the management and prevention of natural hazard events. This paper treats the description of all the procedures carried out in order to produce a map of vulnerability and susceptibility to cave-ins, calculated and evaluated by the multicriteria method (AHP) and by using the GIS tool in the old Medina of Beni Mellal, which is recognized from time to time by cave-ins. The objective of this study is to develop a new method for analyzing the vulnerability of cavities to collapse, which presents a real risk in the urban area of the old cities. The methodology, applied to the old city of Beni-Mellal, consists in identifying and quantifying the stakes linked to the collapse of a cavity using a geographic information system. The weight of each parameter and factor exposed in the vulnerability was estimated using the hierarchical multicriteria method (AHP). The result is presented in the form of a spatialized and synthetic vulnerability map. The detection, mapping and assessment of areas vulnerable to the collapse of these cavities, particularly for large areas of the city, offers the possibility of reducing damage by intervening upstream and introducing preventive and corrective measures against any risk of collapse in the areas deemed vulnerable by our study. The maps show three zones with different degrees of vulnerability. The low and medium vulnerability zones occupy respectively 30 and 20% of the total area of the old city, while the high and very high vulnerability zones occupy respectively 16% and 4%. [ABSTRACT FROM AUTHOR]

The tragedy of the sudden collapse of the 2021 Champlain Towers condominium building in Surfside, Florida raises issues of civil liability and throws into doubt the sustainability of the current model of condominium association governance. This case study evaluates the potential causes of the collapse, and reactions of various parties including the consulting engineering company, city regulators, condominium association board, outside property manager, original builder, and unit owners themselves. By conducting a comprehensive literature review, this paper is aimed to find out the reasons, frequency and liability of building collapse, as well as the roles condominium governance, financial modeling, poverty, or statutory language play in the tragedy. Some advice for further improvements to improve board sustainability is given to original developers, contractors, engineers, and insurance carriers. The current model of condominium management has blind spots and appears to be unsustainable. One suggestion to fix the problem is to require that insurance be obtained to insure the liability of condominium associations, including for this type of tragedy. That would create a financial risk/incentive for the insurance company to ensure adequate management and upkeep. The insurance company should also set board member expertise qualifications, insurance premiums, need for outside expertise, required inspections/maintenance, and replacement reserves that are required to maintain that coverage. [ABSTRACT FROM AUTHOR]

Urban areas in Hong Kong are often developed on hillside due to the lack of land resources. The densely distributed buildings located on the hillslope are thus threatened by landslide hazards. The Po Shan Road landslide occurred on June 18, 1972 is one of the most notable landslides in Hong Kong. The slip area of the landslide was about 270 m × 60 m. Three buildings were destroyed in this disaster: two by direct landslide impact and one by the impact of a collapsed building. In this study, the landslide-building interaction and the building-building interaction in this landslide incident are simulated through explicit dynamic analysis. The landslide and building structures are modelled using the Arbitrary Lagrangian–Eulerian (ALE) method and the Finite Element Method (FEM), respectively. The simulated landslide flow, impact and building failure processes match well the eye witness. The landslide intensity far exceeds the thresholds to reach complete damage of the buildings. The failure mechanisms of the 12-storey residential building, which was a reinforced concrete building with shear walls, are discovered. When the impact force exceeds the ultimate lateral capacity, the building can be pushed forward. The toppled building impacts into an adjacent building block, causing a maximum impact force of over 25 MN. A severe secondary damage thus occurs. The analysis enhances the understanding of landslide-building interactions and helps robust building design. [ABSTRACT FROM AUTHOR]

After a large-scale earthquake, it induces a large number of building collapses and casualties, especially in urban areas. In order to make prevention and response plans before earthquakes, various earthquake loss estimation systems have been developed. The commonly used units of analysis in those systems include grid and village (or administrative district). However, grids are not consistent with streets/roads, making grid-based analyses impractical for evacuation and rescue road planning. As for village-based analyses, a unit covers large spaces and might fail to point out the precise location of collapsed buildings. Therefore, street block, which is a block surrounded by roads, is proposed by the authors as an alternative. To figure out the better analytical units, this study compared street-block-based analyses and village-based analyses. Banqiao District in Taiwan was used as a case to delineate the street blocks by roads with a width of 6 meters or above. Building collapse assessment under peak ground acceleration (PGA) of 400 Gal and 550 Gal demonstrates that street-block-based analyses outperform village-based analyses in terms of locating the collapsed buildings. Moreover, street blocks are readily available for planning evacuation or rescue roads for their consistence with the road network. Results of this study suggest that in urban areas, the higher-resolution spatial analyses of earthquake loss estimation can be made by street-block-based analyses. [ABSTRACT FROM AUTHOR]

The past ten years (2010- 2020), an overwhelming number of buildings (forty-eight) have collapsed in Nigerian urban cities, with about 77% rise from the previous decade. To address this menace, the study aimed at exploring major causes of building collapse in Nigeria as perceived by building industry professionals, policy makers and the public; with a view of establishing effective ways for mitigation. The primary data were obtained from Questionnaires and field observations while secondary data were obtained from textbooks, Journal articles and newspapers. The results revealed that factors such as change of use for building without following professional protocols is a major cause of building collapse. Poor supervision or lack of supervision by qualified professionals; substandard materials, structural failure; government controlling agency not monitoring projects and standards are compromised, a significant amount (27.7%) of collapse cases recorded during constructions. Other factors include faulty architectural and engineering designs; clients not ready to pay for quality jobs and contractors cut corners for profit. The study recommends use of Building Information Modelling to predict behaviour of buildings under various loading and environmental conditions. Also, only certified professionals should carry out design and supervision of projects. Further research should evaluate the role of technology on existing buildings to check the level of safety for occupants’ in such buildings.

The current spate of building collapse in Nigeria has continued to attract research efforts to unravel the causes and possible remedies. Although cases of building collapse in Nigeria has been associated with several factors, those factors associated with building plan approval process have not adequately investigated, especially in a rapidly expanding colonial city of Enugu. The study investigated the role of local town planning authorities in the increasing cases of collapsed buildings in Nigeria using Enugu as a case study. A well-structured questionnaire was administered to the three Chief Town Planners in the three planning approval offices and oral interviews randomly selected 30 developers in ongoing construction projects within Enugu metropolis were conducted. Using content analysis and descriptive statistics the data collected were analyzed. It was observed that due to poor staffing and lack of engagement of building professionals, the planning approval authorities were not effective in scrutinizing, vetting and evaluating building drawings submitted for approval as well as in supervising and monitoring the level of compliance of buildings under construction with the operational building codes and bye-laws in the study area. The study concludes that these lapses in the roles of local building approval authorities can contribute to the increasing cases of collapsed buildings in Enugu Metropolis. It recommends that government should take proactive steps by engaging the right number of building professionals in her planning approval offices and ensuring strict enforcement of the existing physical development legislation and punishment of offenders.

Project SHELTER, Structural Hyper-resisting Element for Life-Threatening Earthquake Risk, aims at developing a strong and stiff functional unit to protect its occupants in case of severe earthquakes that lead to structural collapse. In case of collapse, these units will suffer impacts, particularly if they are installed in upper floors. To avoid severe injuries or death of occupants caused by collapse, safety chairs were designed, provided with shock-absorber systems and auxiliary retaining devices, to keep the occupants properly seated and safe. Three downfall scenarios were evaluated, consisting of vertical and tilted positions. A comprehensive numerical model to represent the human body was developed, mainly focused on chest behaviour and considering the anatomic limits of the vertebral spine. The mechanical ability of the safety chair to ensure the occupants’ safety was evaluated under these harsh conditions. Experimental downfall-and-impact tests will later be performed on shelter units, with crash-test dummies seated on the safety chairs for final validation.

After a large-scale earthquake, the road is susceptible to get blocked by liquefaction or building collapse, and that results in disaster-relief difficulty. This study adopted two earthquake loss estimation systems in Taiwan, and the risk of road blockage caused by liquefaction or building collapse was calculated separately. A new modeling was proposed, and the comparisons of the results of a single factor and that of the joint factors were made. Four scenarios of peak ground acceleration (PGA) = 250, 400, 550, 750 Gal were tested. The result shows that the probability of road blockage due to liquefaction almost reaches the maximum when PGA hits 400 Gal. On the other hand, the probability of road blockage due to building collapse increases if PGA increases. The joint probability of road blockage due to liquefaction and building collapse can improve the underestimation when using either one factor, and it can evaluate the risk more realistically. At present, there is no risk assessment modeling considering two important factors for disaster-relief road planning in Taiwan. This study provides a simple and comprehensive disaster-relief road risk assessment modeling to make better emergency rescue plans. In addition, it can provide the information for conducting seismic strengthening policy for both sides of the disaster-relief road that can reduce the risk of obstacles to disaster-relief roads. [ABSTRACT FROM AUTHOR]

Objective: The building collapse is the main cause of casualties and economic losses in all kinds of disasters. Accurate assessment of the collapse of buildings is an important basis for disaster rescue and government decision-making, and plays an important role in the proper placement of the victims, the protection of the lives and property of the victims. Therefore, the rapid assessment of building collapse after disaster is a research hotspot in the field of remote sensing and civil engineering. The main Objective: of this study was to apply the deep learning technology to automatically identify and assess building collapse and structural damage with on-site images. Methods: The building collapse assessment method used in this paper is ResNet (residual network). A ResNet-50 architecture was implemented in TensorFlow, which consists of 5 stages each with a convolution and identity block, 3 convolution layers in each convolution block and 3 convolution layers in each identity block. According to the building damage assessment standard developed by the China Earthquake Administration, the evaluation output of this model is adjusted to three types: Completely collapsed, semi-collapsed, and non-collapse. In the data augmentation process, geometry transformation and blur processing were used to simulate different shooting environments, to reduce the overfitting of the classifier model by enhancing the training image. Through data expansion, the number of training data has been increased by at least 10 times on the basis of PEER Hub ImageNet Challenge open dataset. In the process of transfer learning, the gradient descent algorithm was used to adjust and optimize the parameters of the neural network. The Results: of this method were evaluated by using accuracy and Kappa coefficient. Results: Finally, in the building collapse assessment experiment, the classification accuracy of the assessment model reached 77.23% and the Kappa coefficient was 0.65; in the structural damage assessment experiment, the classification accuracy of the assessment model reached 77% and the Kappa coefficient was 0.693.The proposed collapse classification successfully attains a relatively high rate for true-positives. Overall, this method performed well. This method shows great promise in supporting on-site decision-making for the rapid accurate assessment of building collapse after disaster. Conclusions: A novel automatic classification method for post-disaster building collapse evaluation is proposed,which meets the building damage evaluation standard. The method is demonstrated on a specific example classification focused on collapse classification and structural damage type identification.The experiment Results: show great promise in the rapid accurate assessment of building collapse after disaster. In the future we plan to improve the model to enhance the ability to extract subtle features in the image. [ABSTRACT FROM AUTHOR]

An earthquake with an epicenter offshore of Hualien City in eastern Taiwan occurred at midnight on February 6, 2018. The Richter magnitude (ML) of the earthquake was 6.26 and the seismic intensity ranged up to level VII, the strongest seismic intensity level regulated in Taiwan. Almost all the major damage resulting from this seismic event was occurred near both sides of the Milun Fault, where records from nearby strong motion stations displayed the characteristics of near-fault ground motions. The main seismic damage was the collapse of four buildings with soft bottom stories, one of which resulted in fourteen of the seventeen total fatalities. Comparing the acceleration response spectra with the design response spectra sheds light on the effects of near-fault ground motions on the collapsed buildings. Based on the eventual forms of collapsed buildings, building collapses that have generally led to major casualties in past seismic events around the world can be classified into sit-down, knee-down and lie-down types. In addition to the four collapsed buildings, seismic reconnaissance on other buildings, bridges, ports, and non-structural components have also been conducted. This study explores the issues and challenges arising from the reconnaissance results and thereby enhances learning from the seismic event. [ABSTRACT FROM AUTHOR]

This paper is a description of the state of the art technical equipment procured during the execution of the project ‟Innovative solutions for stabilizing building and engineering structures as a rescue response during structural collapse recoveryˮ. The project is financed by the National Centre for Research with an execution frame of 2015 to 2017, and carried out by the consortium of the Main School of Fire Service in Warsaw, The Fire Service College of the State Fire Service in Kraków, the Scientific and Research Centre for Fire Protection – National Research Institute and CMGI Sp. z o.o. The technical specifications are presented for an unmanned air vehicle (UAV) built on commission for the Main School of Fire Service; the UAV can be used to monitor rescue mission operations at the sites of collapsed building.

This Lagos-based study provides an unsupervised grouping of the causes of building collapse in Lagos State Nigeria using purposively obtained data from construction professionals (n=34) in the state. Hierarchical cluster analysis technique and mean scores were used for the analyses. Findings show that the causes of building collapse in Lagos State can be statistically grouped into design and construction-related, policy-related and quality-related causes. The most important causes of building collapse under each of these groups are respectively: poor maintenance culture, change of use of building and use of substandard materials in construction. Government needs to strengthen efforts at monitoring both the design and construction of buildings, starting with fine-tuning building related policies. A holistic approach should be adopted in addressing building material counterfeiting and circulation of substandard construction materials in the study area. [ABSTRACT FROM AUTHOR]

The study investigates the effects of building collapse risks on the stakeholders in the Nigerian built environment. Survey research design was adopted in carrying out the research and five cities in Nigeria were selected (Abuja, Ibadan, Port Harcourt, Owerri and Lagos). The target population for the study is the stakeholders in the Nigerian built environment: key professionals in the construction industry, clients/developers and users of the finished product. A sample size of 1999 was chosen using Taro Yamane method. The data generated from 1860 respondents representing 93 % of the distributed questionnaires were presented using frequency tables, pie -charts and bar charts, while analysis was done using percentages and weighted mean. The findings of the study show that building collapse risks have multifarious factors which were categorized as Economic/Financial risks, Socio-political risks, Human related risks, Physical risks, Environmental risks and Law/legal risks. The negative effects of these risks are: loss of property, loss of reputation and integrity of the contractors, loss of lives, legal tussle among the stakeholders, etc.. It was also found out that economic/financial risks have the predominant effect on the stakeholders, followed by Human related risks, Socio-Political risks, Physical risks, Environmental risks and lastly Law/Legal risks. It was recommended that all hands should be on deck to curb the havoc caused by building collapse as the effect is usually felt by all and sundry. There should be adequate funding and monitoring of the activities of all Emergency Management Agencies. [ABSTRACT FROM AUTHOR]