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Highlights • Adding value to management research for improving safety on construction sites. • Use of a psychological contract of safety model to influence safety behaviour. • Structural Equation Modelling to validate psychological contract of safety model. • Empirical data collected from a mega construction project. • Relationships examined between safety climate factors and psychological contact. Abstract The relationship between safety climate and safety behaviour is well established in construction, however, the way safety plans and actions of top management translate to the workforce is still unclear. Considering the influence of supervisors' behaviour on workers' safety behaviour and conceptualizing safety through the lens of the 'Psychological Contract' (PC), it is argued that 'Psychological Contract of Safety' (PCS), could be a vital factor to explain how workers attach meaning to supervisor behaviour at construction sites and prioritise safety issues. Previous research suggests that (1): safety climate is based on perception of workers regarding safety and (2): PCS is based on perceived mutual obligations between workers and supervisors. As a result, if PCS or mutual obligations between workers and supervisors are fulfilled, then safety behaviour of the workers will be positively influenced. A model depicting the PCS as an alternative intervention in understanding how safety climate factors influence workers' safety behaviour is presented. Using Structural Equation Modelling (SEM) the model of the PCS is validated. The model explains how construction safety is influenced by the mutual safety obligations between supervisor and workers. [ABSTRACT FROM AUTHOR]

Highlights • To accommodate large influx of occupants many high rise buildings are constructed. Safety is uncertain in the time of an emergency due to events such as fire accidents. • A generalized stochastic petri net model is developed for a multi floor building considering the two cases, with and without the human behavior constraints and evaluate the performances. • The performance of the modeled system has been analyzed in terms of throughput, pre evacuation delay and evacuation time. • This estimation can be used by the architects to design buildings with required stair-widths floor exits and other features such as to avoid congestion. • With the inherent strong mathematical foundation of SPN based models compared to other modeling approaches, it is reliable to apply and analyze the behavior of occupants in high rise buildings. Abstract Construction of multi-floor buildings have increased multifold in the urban areas due to scarcity of space for the growing population. There is a need for safe evacuation of people in such multi floor buildings during emergency situations such as fire occurrence. In this paper, we present an analytical model of the evacuation scenario on accidental fire using stochastic petri nets. The proposed evacuation model takes into account human behavior parameters such as panic among occupants, and realistic situations namely stampede in the stairwell, and distance of each occupant to the floor exits. The performance of the system is evaluated in terms of evacuation time, pre evacuation delay and average system throughput and compared with those of the evacuation model without human behavior and realistic constraints. The analytical results are validated using the real time evacuation drill measurements in a 10 storey building. [ABSTRACT FROM AUTHOR]

Highlights • Developing a multi-criteria ranking system for administrative buildings evacuation evaluation. • Using Agent-Based Simulation to rate the overall evacuation performance of administrative buildings. • Performing sensitivity analysis to rank the criteria, taking into consideration the criticality degrees. Abstract It is of utmost importance to assess the level of safety provided by the building structure to its occupants in normal conditions and more importantly in fire incidents. Qualitative indicators tend to dominate the evaluation systems for building evacuation which means that these are limited to experts and key decision makers to evaluate them and this is not practical. Thus, new quantitative and objective evaluation criteria are necessary to accurately reflect the evacuation situation. Therefore, there is a need to develop a method that is both quantitative and qualitative to assess the evacuation performance of buildings. This research provides support to the implementation of buildings evacuation performance evaluation, with the aim of maximizing the occupants' safety and deciding between multiple safe design alternatives. The objective of this study is to develop a multi-criteria ranking framework that integrates 3D modelling with Agent-Based Simulation (ABS) and Decision Support Tools. This will lead to quantitatively rate the overall evacuation performance of code compliant buildings, taking into consideration the many factors and criteria affecting the process. The proposed framework can be used by insurance companies to rank the different buildings that need insurance especially in case of limited funds and many acceptable options available. It can also be utilized by designers to evaluate the various design alternatives in order to select the optimum one or evaluate the performance of current evacuation plans in use. A case study was conducted to delineate the proposed framework features and its results were thoroughly analysed. Sensitivity analysis was also carried out to determine the most sensitive criteria used for the decision-making process. [ABSTRACT FROM AUTHOR]

In this paper, we have developed an interval type-2 fuzzy logic controller  (T2FLC) approach for assessment of the risks that workers expose to at construction sites. Using this novel approach, past accident data, subjective judgments of experts, and the current safety level of a construction site are to be combined. The method is then implemented on a tunneling construction site and risk level for all type of accidents is formulated. In T2FLC assists to trace inputs and outputs in a well-organized manner for building the inferences train so that various types of risk assessment can be predicted in industry. Finally, a comparative study has been successfully performed with type-1 and type-2 fuzzy dataset for improving risk assessment that can be easily determined in the type-2 fuzzy prediction model for improving accuracy. Validity of the proposed model is done with the help of statistical analysis and multiple linear regressions. [ABSTRACT FROM AUTHOR]

Abstract Pervasive unsafe behaviors of construction workers are the primary cause of accidents on construction job sites. The workers' safety-related behaviors are subject to a variety of factors, such as interactions with coworkers and interventions by management teams. The impacts of these factors have attracted considerable attention in academia but are yet to be fully examined. To provide a quantitative assessment of these impacts and their managerial implications in practice, an agent-based modeling approach of construction safety-related behaviors, which adopts a bottom-up architecture, is proposed in this research. This approach regards safety performance as an emergent property of the behaviors and interactions of construction workers and management teams. The development of the agent-based model is based on a range of theoretical and empirical evidence, including a cognitive analysis model for modeling worker behaviors, and site observations and surveys for the design of simulated working environment and tasks, as well as the modeling of individual behaviors and interactions. Four managerial scenarios are simulated using the proposed approach. Based on the simulation results, the effects of a number of managerial factors on the safety performance of construction workers are examined. These factors include duties of supervisors, the competency and inspection strategy of safety officers, the frequency of safety training, senior managers' involvement in safety activities and emphasis on safety goals. The effects of these factors are examined in a quantitative manner, and relevant implications for construction safety management practice are discussed. The findings prove that agent-based modeling is an effective approach for analyzing the characteristics and patterns of construction safety-related behaviors and assessing possible safety management strategies. Highlights • An agent-based model was proposed to simulate construction safety related behaviors. • Managerial behavior was examined quantitatively in four simulated safety scenarios. • Worker and management agents' behavior adapted over time based on their interactions. • Interactions with management agents impacted worker agents' safety performance. • The model was proven to be useful for studying construction safety related behavior. [ABSTRACT FROM AUTHOR]

Highlights • Carcinogenic PAHs released by hot mix asphalt are detectable only in the fume phase. • 1-Hydroxypyrene is a valid biomarker for biomonitoring of asphalt workers. • 2-Naphthol suffers a higher confounding effect by smoking habits. Abstract Objectives We performed a cross-sectional study with the main aim of evaluating occupational exposure to polycyclic aromatic hydrocarbons (PAHs) in workers involved in the pavement construction of a new highway in Northern Italy, where modified bitumen was used as binder for Hot Mix Asphalt. Methods We applied a combined approach of air and biological monitoring. Both the aerosol and vapour phases of bitumen were collected applying the NIOSH 5506 method. The 16 PAHs listed as high priority by EPA were determined by HPLC-UV. End-of-shift urine samples were collected from 144 workers to determine 1-hydroxypyrene (1-OHP) and 2-naphthol (2-NAP) concentrations after enzyme digestion and HPLC-UV analysis. Socio-demographic and lifestyle information was collected by a questionnaire. Results Paving workers were actually exposed to PAHs, including carcinogenic compounds, that were measurable only in the aerosol phase. Higher exposure as well as dose levels were measured for the paver group. Biological monitoring confirmed that 1-OHP was less affected by smoking habits as compared to 2-NAP and showed a higher association with occupational exposure. Conclusion Carcinogenic PAH compounds were detectable only in the aerosol phase and this must be taken into account in the adoption of preventive measures. Biomonitoring supported the superiority of 1-OHP as compared to 2-NAP in assessing the internal dose in such workers. [ABSTRACT FROM AUTHOR]

This study proposes a proactive struck-by risk detection method for workers proximal to the laydown area. This approach regards the laydown area as a radiation source, and proactive struck-by risk detection is formulated as a location-based estimate of radiation quantity received by the worker. The position probability grid is adopted to track the worker and model their movement. The movement pattern model, which is learned from the trajectory records of the workers in the same trade, reflects the movement preferences of different trades, and the randomness model represents the randomness of worker movement. The worker's next location can be predicted by using the tracked location and movement model, and the struck-by risk can then be estimated. The method's potential for integration into currently available proximity warning systems is also demonstrated. [ABSTRACT FROM AUTHOR]

A highly challenging problem that has been plaguing regulators is the inaccurate collection and sharing of safety risks for underground construction. In order to establish a mechanism that could achieve timely and accurate recognition at the pre-construction stage, Building information model (BIM) is adopted as the risk recognition platform. This paper provides the automated safety risk recognition process based on BIM which is generally composed of three parts. The first part is to build the risk database. By means of knowledge structuralizing, questionnaires, depth interviews and group decision-making, explicit and tacit knowledge source are acquired. The safety risk knowledge source is divided into three categories. SQL database is used to express the safety risk knowledge, and all safety risks are stored in the BIM-cloud. The second part is to analyse the relation between engineering information and safety risks. Risk-related engineering information is extracted from BIM models. Backus–Naur form is used to describe the syntax of languages used in computing. A mapping table of engineering information and safety risks is established. The third part concerns the automated safety risk recognition mechanism in the BIM platform. The safety risk recognition mechanism is expressed as “If e, then h (CF (h, e), λ)”. The confidence level as the link is adopted to reveal the mechanism. Finally, a case about flowing sand risk at the foundation pit bottom is conducted. The reasoning process and recognition results are demonstrated. The paper concludes by summarizing the main scientific contribution and giving direction to future research in this field. [ABSTRACT FROM AUTHOR]

Quickly changing and complicated workplace conditions, which are typical of construction projects, have always been contributing to the poor safety record of the construction industry. However, few of the existing approaches to reviewing control measures take into account or effectively tackle these conditions. This paper introduces a three-level (i.e., individual hazards, hazard types, and generic hazards) hierarchical Bayesian model based on workers' responses to proximity warnings of safety hazards to address the problem. The proposed model distinguishes between two uses of proximity warnings (i.e., as the primary control measure and as the secondary measure), uses observational response rates as input, takes into account prior knowledge of workers' responses to similar hazards, and produces estimated response rates (ERRs). These ERRs are the primary indicator of the effectiveness of a given control measure as well as of the validity of a previously identified safety hazard. A 17-day field experiment was conducted to test the proposed approach, preliminarily using a locationbased proximity warning system to warn workers of safety hazards and record their responses to warnings. The experimental results demonstrated the potential of the proposed approach. The limitations of the present analysis and the directions for future research are also discussed. [ABSTRACT FROM AUTHOR]

Computational tools and numerical strategies for the determination of the response of masonry walls under blast overpressure often rely on oversimplifying and conservative assumptions, which, although justifiable for design purposes, are not as warranted when fragility analysis and risk assessment are the objectives. In addition, due to the composite nature of reinforced masonry construction, the evaluation of multivariate fragility functions may likely require significant computational effort, owing to the multiplicity of variables describing the constituent materials and their associated uncertainty. The problem is further compounded by the effects of the high strain rates typically induced by blast loading, which make the understanding of masonry behaviour even more challenging; although efforts are being made in order to account for strain rate effects at the macro-scale, no well established models are available for reinforced masonry walls. Therefore, in order to perform accurate yet expedient fragility analyses that can effectively capture rate dependent phenomena, a dynamic model based on single-degree-of-freedom (SDOF) approach is developed. The SDOF model accounts for the nonlinear stress–strain behaviour obtained from standard prism tests and integrates strain rate dependent formulations provided in the open literature. The model predictions are corroborated using data—including pressure and displacement histories—from field testing of six scaled concrete block walls subjected to the detonation of live explosives. Within the scope of the current study, the proposed model is found to be a reasonable trade-off between computational efficiency and numerical accuracy and is an improvement upon a basic SDOF approach, which is typically based on the fixed dynamic increase factors recommended by modern design standards and technical manuals for blast protection. The results presented in this study are expected to contribute to the ongoing development of a comprehensive framework for the probabilistic risk assessment of structures subjected to explosive loading. [ABSTRACT FROM AUTHOR]

This paper presents a simplified method for evaluating the risk of progressive collapse of reinforced concrete (RC) buildings. The method is formulated based on a recently developed two-scale numerical model for RC structures. In this model, all structural members are modeled by a set of coarse-scale cohesive elements representing the potential damage zones (PDZs). The cohesive constitutive behavior is determined by fine-scale finite element (FE) simulations of the corresponding PDZs. In the present study, a new energy-equivalent linear elastic cohesive model is developed for RC buildings. The damage status of the PDZ is determined by comparing the elastic energy stored in the cohesive element with the actual energy dissipation capacity of the PDZ. This model is applied to analyze the behavior of a two-dimensional frame subassemblage under a column removal scenario, and it is shown the model is capable of capturing the total energy dissipation of the entire failure process. This cohesive model is combined with a sequential analysis method to identify different possible failure paths leading to collapse initiation. The present model is applied to analyze the collapse initiation risk of a prototype RC building, where the randomness in both gravity loads and material properties is taken into account. The results are compared with the recent simulations using a nonlinear dynamic model. It is shown that the present analysis is much more efficient than the conventional nonlinear dynamic analysis, and it yields a reasonable upper bound of the collapse probability. [ABSTRACT FROM AUTHOR]

The concept of disaster-resilient communities has gained considerable acceptance and attention over the past decade, requiring the assessment of not only the monetary losses surrounding a hazard, but also the complex, time-dependent factors that influence community resilience. This paper presents an analytical, reliability-based approach to quantify seismic resilience based on the robustness and restoration rapidity of a portfolio of buildings following an earthquake event. The reliability problem is formulated using random variables to describe the spatially correlated seismic intensity, structural response, and duration of posthazard recovery for predefined building combinations within a portfolio. Based on these random variables, the first-order reliability method (FORM) is used as a basis to develop a new algorithm to evaluate a probability distribution of resilience for a suite of spatially distributed buildings. In addition, sensitivity measures are computed within FORM and used to prioritize cost-effective mitigation strategies to increase portfolio resilience. This assessment puts prehazard retrofit and posthazard restoration measures into a common preposterior framework to determine the most optimal allocation of resources to improve resilience given budgetary constraints. Preliminary results indicate that prehazard retrofit is often most cost-effective for increasing resilience; however, posthazard restoration efficiency is more cost-effective for achieving high resilience thresholds characterized by longer return periods. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach of integrating Building Information Modeling (BIM) and expert systems to address deficiencies in traditional safety risk identification process in tunnel construction. A BIM-based Risk Identification Expert System (B-RIES) composed of three main built-in subsystems: BIM extraction, knowledge base management, and risk identification subsystems, is proposed. The engineering parameter information related to risk factors is first extracted from BIM of a specific project where the Industry Foundation Classes (IFC) standard plays a bridge role between the BIM data and tunnel construction safety risks. An integrated knowledge base, consisting of fact base, rule base and case base, is then established to systematize the fragmented explicit and tacit knowledge. Finally, a hybrid inference approach, with case-based reasoning and rule-based reasoning combined, is developed to improve the flexibility and comprehensiveness of the system reasoning capacity. B-RIES is used to overcome low-efficiency in traditional information extraction, reduce the dependence on domain experts, and facilitate knowledge sharing and communication among dispersed clients and domain experts. The identification of a safety hazard regarding the water gushing in one metro station of China is presented in a case study. The results demonstrate the feasibility of B-RIES and its application effectiveness. [ABSTRACT FROM AUTHOR]

This paper presents a systemic Bayesian network (BN) based approach for dynamic risk analysis of adjacent buildings in tunneling environments, consisting of risk/hazard identification, BN learning and BN validation. Two validation indicators are proposed to evaluate the effectiveness of the established BN model, aiming to ensure that the model predictions are not significantly different from actual observations. In the dynamic risk analysis framework, the predictive, sensitivity and diagnostic techniques are used to conduct the feed-forward control in the pre-construction stage, intermediate control in the construction stage and back-forward control in the post-accident stage, respectively. A case regarding some existing buildings adjacent to construction of the Wuhan Yangtze metro tunnel in China is presented. The results demonstrate the feasibility of the proposed approach, as well as its application potential. The proposed approach can be used by practitioners in the industry as a decision support tool to provide guidelines on the conservation of adjacent buildings against tunnel-induced damages. [ABSTRACT FROM AUTHOR]

The achievement of demolition works on structures, by authorized personnel, using explosives, implies a combination of risks that exist on any construction site with the specific risks of work with explosives. These specific risks are generated mainly by the effects of explosions and partial or total misfires. The requirements and the feasibility to demolition of construction, requires on behalf of companies carrying out demolition with explosives to identify and assess the risks to which workers may be exposed during the destruction of the building elements and also to achieve the initiation schemes for explosions at the best price/efficiency ratio. [ABSTRACT FROM AUTHOR]

The article discusses the premises for the utilization of risk assessment in evaluating the robustness of structures. It mentions that robustness assessment is understood as a process of decision making based on risks. It notes that risk assessment should regard all stages of a technical system, from the early concept stage to the end of service life, including decommissioning.

Abstract: Problem: One of the phases with the highest risk of falls from a height in the construction of a building is during the floor slab formwork stage. This paper analyzes this particular risk, as well as the most frequently used fall-protection systems. Method: A survey was carried out to define the current situation in Spain with regard to falls from a height during floor slab formwork and the fall-protection systems used to prevent such a risk. Results: The results of the survey clarified the current situation in Spain with regard to this risk, and made it clear that there is considerable risk of falling from a height during the floor slab formwork stage. Discussion: All the safety systems analyzed presented a series of weak points that should be studied in detail before they can be used on building sites. Impact on industry: The risk of falling associated with floor slab formwork and the most frequently used protection systems are analyzed. As no research had been carried out to date on this type of risk, we consider the research presented in this article to be a pioneer in the field. [Copyright &y& Elsevier]

Interference problems of construction processes are especially disturbing due to their big scope of variability, uncertainty and complexity what significantly hinders planning and accomplishing the production processes on the building site. Monitoring of environment (which generates interference) and processes in progress enable to undertake activities aiming at introducing flexibility in managing of processes which may significantly increase the efficiency of systems ensuring quality in building. The described CONLI (CONcrete on-LIne) system is an effective device of monitoring which enables the transfer of information in real time to different decision-makers (e.g. site manager, supervision inspector, investor and the like) owing to wireless transmission and hybrid structure taking into account diverse scope of access depending on requirements of maintaining necessary data confidentiality. [ABSTRACT FROM AUTHOR]

This paper describes progressive collapse assessment of an existing reinforced concrete commercial building. Prescriptive guidelines available to date are evaluated in light of alternate load path predictions. The building, exceedingly meeting ACI integrity requirements and the recent United Facilities Criteria tie force provisions, is still significantly vulnerable to progressive collapse triggered by the loss of an interior column. [ABSTRACT FROM AUTHOR]

A thorough analysis of the accidents in the Polish building industry in years 1992-2004 is presented. The accident situation, if assumed to be a homogeneous phenomenon, is estimated based on the accident rate of minor, serious and fatal accidents and all the accidents jointly as well as based on the accident seriousness index. However, the accident situation is not a homogeneous phenomenon. The frequency of the particular kinds of accidents and their structure change over the years. The standardised accident rate (which takes into account all the kinds of accidents and their structure at the same time) is proposed for the estimation of the accident situation treated as a non-homogeneous phenomenon. It is constructed the model of development tendency for a phenomenon according to the information on the accident situation expressed by the accident rate and the accident seriousness index in the years 1992-2004. [ABSTRACT FROM AUTHOR]