Spatial and Temporal Exposure to Safety Hazards in Construction

Given the dynamic nature of construction sites, analysis of construction activities and their related hazards is inadequate for reliable risk assessment if it does not explicitly account for the likelihood of exposure of potential victims to hazardous situations. In traditional risk level calculations for manufacturing industries, the number of victims is factored with the likelihood of an accident and the potential severity, but the victims are simply assumed to be those typically present at the accident location. In construction, exposure cannot be accounted for at a generic metaproject level: it must be assessed at the level of the activities and the physical context in which they are performed. Conceptually, accidents are “loss-of-control events” to which victims are exposed; without exposure, no accident is assumed to occur. A set of algorithms has been developed to demonstrate estimation of the likelihood of exposure of construction workers to loss-of-control events. The algorithms have been implemented in a prototype software application designed to predict fluctuating risk levels in construction projects. The software implements the “construction hazard assessment with spatial and temporal exposure” model for managing safety in construction, which empowers planners at all levels to adjust construction plans to mitigate high levels of risk or to undertake appropriate proactive measures to ensure safety when high risk levels are unavoidable.     

Construction Safety Risk Mitigation

Construction safety and health management has improved significantly following the Occupational Safety and Health Act of 1970. In response to this legislation, contractors began implementing safety programs to reduce occupational safety and health hazards on construction sites. Researchers recently found that the current process of selecting specific elements for a safety program is informal. This paper describes the results of a recent study designed to determine the relative effectiveness of safety program elements by quantifying their individual ability to mitigate construction safety and health risks. In order to determine the effectiveness of individual safety program elements, the following research activities were performed: (1) an appropriate safety risk classification system was created using an aggregation of relevant literature; (2) highly effective safety program elements were identified in literature; and (3) the ability of each safety program element to mitigate a portion of each of the safety risk classes was quantified using the Delphi method. The results of the research indicate that the most effective safety program elements are upper management support and commitment and strategic subcontractor selection and management and the least effective elements are recordkeeping and accident analyses and emergency response planning. It is expected that the data presented in this paper can be used to strategically select elements for a safety program, target specific safety and health risks, and influence resource allocation when funds are limited.     

Identification and Analysis of Factors Affecting Safety on Construction Sites with Tower Cranes

Tower cranes are the centerpiece of production on today’s typical building construction sites. Tower cranes hoist and transport a variety of loads near and above people, working under crowded conditions, occasionally with overlapping work zones, and often under time, budget, and labor constraints. This work regime further increases the safety risk on sites that are inherently hazardous workplaces. This paper presents the results of a study that identified the major factors affecting safety in tower-crane environments and evaluated the degree to which each factor influences ongoing safety on site. Use of statistical data on accidents was ruled out as a source of information due to the countless number of incidents that go unreported, the common inability of statistics to provide root causes, and the questionability of statistics as a predictor of accidents. The research methodology was therefore based on comprehensive questioning of an expert team that included the safety managers and equipment managers of leading construction companies. With the limited resources available for safety improvement and accident prevention, greater attention must be paid by all parties involved to those factors evaluated as highly affecting site safety due to tower-crane work.     

Case for Drug Testing of Construction Workers

Drug use has been shown to have a negative affect on both job safety and productivity. Due to the high accident rates in the construction industry it is vital for management to take necessary steps to implement programs and procedures that will increase construction safety and worker productivity. While the effects of a drug-related jobsite accident can be catastrophic for individuals and companies, management should realize that drug use among employees can be damaging to moral, productivity, and quality even if it does not result in accidents. The level of teamwork required for excellent work is harder to achieve and efforts to improve project management by team building are hurt by the absenteeism and short-term employment typical of the employee that abuses drugs. Other areas where the project management of a construction company is compromised by worker drug use are recruitment and retention of human resources, career growth management, and safety. Drug testing construction workers is an effective method for reducing the number of impaired workers on a project site, increasing overall project safety, worker morale, productivity, and profits. There are ethical and legal questions on both sides of the issue and any such management initiative must be balanced with worker rights.     

Safety Risk Identification and Assessment for Beijing Olympic Venues Construction

New technologies, new materials, and innovative designs have been extensively adopted in Beijing Olympic venues construction. The extreme requirements for time deadline and competition function expose the venues construction to high risks. These risks would potentially bring negative impacts on the site safety performance. Meanwhile, there is a lack of systematic management for safety risks in China’s construction industry, especially for large projects such as the Beijing Olympic venues construction. This paper identifies and assesses safety risk factors inherent in Beijing Olympic venues construction with the involvement of 27 experienced and highly respected experts from government agencies, the construction industry, and academe through brainstorming, workshop discussions, and questionnaire surveys. The finding reveals that more than half of the critical safety risk factors are from contractors and subcontractors such as: lack of emergency response plan and measures; workers’ unsafe operation, and contractors ignoring safety under schedule pressure. Based on these critical safety risks, a risk register is composed and a model is developed in application of the analytic hierarchy process to assess the status of risks on site safety. The model has been attempted in two Olympic venue projects under construction and the validity has been approved. The risk checklist, register, and assessment model developed in the paper were integrated into the risk management system that has been used for Beijing Olympic venues construction.     

Comparative Study on the Perception of Construction Safety Risks in China and Australia

Safety is a major concern in the construction industry because fatalities and injuries from construction work bring great losses to individuals, organizations, and societies as a whole. This paper aims to understand how construction personnel perceive safety risks in China as compared with those in Australia. Postal questionnaire surveys were used to collect data on safety risk perceptions from the two nations. The safety risk factors were assessed using a risk significance index based on the likelihood of occurrences and the impacts on safety performance. The survey results revealed that in China the main perception of safety risks came from human-and/or procedure-related issues, with “low/no safety education” paramount, followed by “inadequate fire prevention and electrical prevention procedures,” etc. In contrast, the major safety risks perceived in Australia were related to the environment and physical site conditions with “contamination of land, water and air” ranked first, followed by “unforeseen excavation of soil,” etc. To minimize construction safety risks in China, this paper suggests that the government should develop collective legislation and safety protection procedures, and enforce safety education and training to all site participants. Risks related to environmental and site conditions were generally realized by the Australia construction industry, which were not highly acknowledged in China. This may also bring imminent attention in this regard to the Chinese government.     

Fuzzy Analytical Hierarchy Process Risk Assessment Approach for Joint Venture Construction Projects in China

Research and practice show that construction joint venture (JV) activities in China are opportunities that can bring potential benefits but at the same time may generate many risks. While research has studied these risks and presented useful advice for managing individual risks, the methodologies used to analyze the risks were mainly qualitatively based, and there is a gap in using the quantitative method that can integrate a risk expert’s knowledge to assess the risks associated with JV projects. This paper sets up a hierarchy structure of the risks and then develops a fuzzy analytical hierarchy process (AHP) model for the appraisal of the risk environment pertaining to the JVs to support the rational decision making of project stakeholders. An empirical case study is used to demonstrate the application of the proposed fuzzy AHP model. It is concluded that the fuzzy AHP model is effective in tackling the risks involved in JV projects. The information presented in this paper should be shown to all parties considering JV business opportunities in China, and the proposed approach should be applicable to the research and analysis of risks associated with any type of construction projects.     

New Method for Measuring the Safety Risk of Construction Activities: Task Demand Assessment

The task demand assessment (TDA) is a new technique for measuring the safety risk of construction activities and analyzing how changes in operation parameters can affect the potential for accidents. TDA is similar to observational ergonomic methods—it does not produce estimates of probabilities of incidents, but it quantifies the “task demand” of actual operations based on characteristics of the activity and independent of the workers’ capabilities. The task demand reflects the difficulty to perform the activity safely. It is based on (1) the exposure to a hazard and (2) the presence and level of observable task demand factors—that is, risk factors that can increase the potential for an accident. The paper presents the findings from the initial implementation of TDA and demonstrates its feasibility and applicability on two different operations: a roofing activity and a concrete paving operation. Furthermore, the paving case illustrates how the TDA method can compare different production scenarios and measure the effect of production variables on the accident potential. The findings indicate that the method can be applied on activities of varying complexity and can account for several risks and task demand factors as required by the user. The selection of task demand factors is a key issue for the validity of the method and requires input from the crew and safety management. The limitations of the methodology and the need for further research are discussed. Overall, TDA provides a tool that can assist researchers and practitioners in the analysis and design of construction operations.     

Incident Causation Model for Improving Feedback of Safety Knowledge

In order for the construction industry to improve its poor safety performance it needs to learn from its mistakes and put the lessons learned to good use. This need calls for effective feedback mechanisms that can transmit information derived from incident investigation to be utilized in safety planning. The feedback should be at two levels; first, feedback to the Safety Management System that had failed, and second, feedback to the safety planning of future projects. The first level of feedback can be achieved by basing the investigation on an incident investigation model that explicitly identifies system failure. The second level of feedback can be achieved if both incident investigation and safety planning share the same incident causation model, such that the information from each process can be retrieved and utilized in the other process smoothly. One prerequisite to fulfill the two levels of feedback is the development of an incident causation model. In this paper, the modified loss causation model (MLCM), which is able to meet the above-mentioned purposes, will be presented. The MLCM is developed based on an extensive literature review and application on 140 actual accident cases obtained from Singapore’s Ministry of Manpower, Occupational Safety Department. In this paper, the model’s application will be demonstrated through a case study, which involves codification of investigation information based on an actual incident report, and a safety planning process based on a hypothetical case.     

Benchmarking Studies on Construction Safety Management in China

This paper presents information by which to measure safety management performance on construction sites. In China, the conventional construction safety benchmarking approach is to assess safety performance by evaluating the physical safety conditions on site as well as the accident records, while no attention has been paid to the management factors that influence site safety. This paper is to identify the key factors that influence safety management and to develop a method for measuring safety management performance on construction sites. Based on the survey and interview data collected on safety management factors in 82 construction projects in China, the safety management index as a means to evaluate real-time safety management performance by measuring key management factors was developed. The quantified factors were compared with the commonly accepted physical safety performance index, which was derived from inspection records of physical safety conditions, accident rates, and the satisfaction of the project management team. Multifactor linear regression was conducted and the result indicates that safety management performance on site is closely related to organizational factors, economic factors, and factors related to the relationship between management and labor on site. Based on this benchmarking study, a practical safety assessment method was developed and then implemented on six construction projects. The results show that this method can be an effective tool to evaluate safety management on construction projects.     

Critical Activities in the Front-End Planning Process

Previous research conducted by the Construction Industry Institute (CII) and others has demonstrated the value of front-end planning as it impacts project success. A recently completed research project funded by CII, described in this paper, examines ways to improve information flow through the front-end planning process. This paper focuses on one specific objective of this research project, namely to isolate and closely examine the information critical activities within the front-end planning process. The front-end planning process was carefully diagrammed as consisting of 33 distinct activities, each with its own information flow entities and interactions. Fifty-one questionnaire survey forms were analyzed to obtain data for the 33 activities that included activity duration, resources expended, and the extent to which information was available to perform the activity. The 51 projects were then grouped according to survey respondents’ perceptions as to whether the front-end planning process was executed more or less effectively. An analysis of the data concluded with a degree of statistical significance that seven of the 33 activities have some impact on achieving project success. In addition, statistically significant differences were uncovered with respect to the extent that information was available for selected activities, and survey respondent perceptions with respect to how efficiently the activity was performed. These seven activities are involved in planning the following areas: Public relations, start up, quality and safety, the project execution plan, and project scope definition. Other activities for which information was frequently not available and/or for which considerable resources were expended relate to preliminary cost estimating and the development of a funding plan. A second survey form was forwarded to the original survey participants to obtain more specific information with respect to the information categories and interfaces associated with the critical activities that were identified in the original survey. This survey indicated problem areas including inadequate scope definition, risk identification and mitigation, minimal resource allocation for task execution, unclear definitions of roles and responsibilities, and ineffective external communication mechanisms.     

Construction Safety in Kuwait

In gulf region countries like Kuwait, the construction process can become very challenging. In this paper, we analyze construction-related accidents in Kuwait including type of accident, type of injury, body part injured, and accident outcome for the years 1996–2007. We present examples of recent cases and evaluate these cases presenting current Kuwaiti rules and legislation and providing suggestions for ensuring a safer construction environment. As this research shows, the construction industry is the most hazardous industry in Kuwait. On average, falls are the major type of accident (33.2%) followed by being crushed or struck by a falling object (25.2%). Use or misuse of tools caused the third largest number of accidents in Kuwait (18.1%). The most frequent type of injury is fractures (52.6%) and the most common injured body part is the upper body (53.4%). An average of (82.7%) of victims of construction accidents in Kuwait sustain permanent disabilities. It is clear that the Kuwaiti construction industry has a safety problem and that there is a pressing need to change current practices and legislation in construction and building sites.     

隐患分级在气瓶安全管理中的实践

氧气气瓶充装作业作为危险化学品作业,存在火灾、爆炸等危险因素,为避免事故的发生,根据多种隐患辨识途径,确定气瓶充装作业存在的安全隐患,从人、机、环、管四个方面分级建立适用性的隐患评估标准,并提出相应的隐患控制措施。     

Predictive Tool for Estimating Accident Risk

This paper presents a predictive tool that uses safety factors to estimate accident risk for processes commonly employed on construction sites. The tool is demonstrated in the context of the utility-trenching process. Based on expert surveys, preplanning, supervision, and training are identified as critical safety factors needed to predict accident risk when evaluating safety performance related to trenching operations. Preplanning has a greater impact on excavation tasks than supervision and training, while conversely, supervision and training are more important during the pipe installation phase of trenching operations.     

Risk-Based Safety Impact Assessment Methodology for Underground Construction Projects in Korea

Safety of construction projects may be affected by various factors such as types and scale of projects, construction methods, safety management procedure, climate, site conditions, etc. Among them is the quality of design in relation to safety. Presently, however, designers typically are not involved in construction safety. They are often uncertain of their responsibilities in relation to construction safety and fail to be responsible for avoiding or reducing safety-related risks. In this study, the concept of safety impact assessment to achieve “design-for-safety” in the design phase is introduced. For this purpose, a safety impact assessment model was devised, and a methodology using the risk-based safety impact assessment approach for open-cut type underground construction projects in Korea is suggested. The suggested methodology includes a safety information survey, classification of safety impact factors caused by design and construction, and quantitative estimation of magnitude and frequency of safety impact factors. A checklist which can be easily used for assessing the safety performance of design products is also proposed. A real-world case study on the safety impact assessment of a subway construction project in Korea is also provided in the paper.     

试析锌冶炼企业安全风险和管控途径

锌冶炼企业是我国社会主义市场经济体系当中一个很重要的组成部分,金属锌作为诸多工业产品深加工的原材料,占有重要地位,但是对锌冶炼行业来说,冶炼生产存在一定的安全风险,在生产过程如管理不善往往会形成一些安全隐患最终引发生产安全事故,因此需要加强冶炼生产风险管控,杜绝发生生产安全事故。     

冶金工贸行业小微企业安全标准化管理信息系统的研究

分析了冶金等工贸行业小微企业安全标准化管理系统的11个要素,确定管理信息系统的主要目标及使用的关键技术特点,建立了对应的11个功能模块,并对管理信息系统各模块实现的功能进行了介绍。将冶金等工贸行业小微企业安全标准化管理设定的各类安全信息及安全管理内容融入到信息系统管理之中,实现了对安全管理过程中大量积累数据的分析和处理,实时动态地展示工艺、环境、设备、安全、管理状况和员工的危险行为,可以及时有效地进行风险控制,达到降低事故发生的目的。     

AHP-Based Weighting of Factors Affecting Safety on Construction Sites with Tower Cranes

Aspiring to adopt a nonstatistical quantitative approach to safety assessment, this study implements a multiattribute decision-making tool to elicit knowledge from experts and formalize it into a set of weighted safety factors. The environment addressed is the construction site and the specific factors studied are those affecting safety due to the operation of tower cranes. Nineteen senior construction equipment and safety experts were interviewed and led through the analytic hierarchy process (AHP) to provide their assessments on the relative importance of safety factors obtained in an earlier study. The results accentuate the dominance of the crane operator and general superintendent on the site safety scene and play down the contribution of “classic” site hazards such as power lines. Quantitative measuring of safety, such as reflected in the weights obtained in this study, is important in communicating safety requirements and focusing the limited resources available for safety improvements. These factor weights are also deemed to be a vital component in the development of a comprehensive model that will allow the computation of safety indices for individual construction sites employing tower cranes. It is expected that the methodology can then be adopted for addressing other site safety issues as well.     

A discussion of regulatory requirements and air dispersion modeling approaches applicable to U.S. chemical demilitarization facilities

Owners of hazardous waste treatment, storage, and disposal facilities, and certain major air pollution sources, must conduct several separate ambient air dispersion modeling analyses before beginning construction of new facilities or modifying existing facilities. These analyses are critical components of the environmental permitting and facility certification processes and must be completed to the satisfaction of federal, state, and local regulatory authorities. The U.S. Army has conducted air dispersion modeling for its proposed chemical agent disposal facilities to fulfill the following environmental regulatory and risk management requirements: (1) Resource Conservation and Recovery Act human health and ecological risk assessment analysis for the hazardous waste treatment and storage permit applications, (2) Quantitative Risk Assessment to support the site-specific risk management programs, and (3) Prevention of Significant Deterioration ambient air impact analysis for the air permit applications. The purpose of these air dispersion modeling studies is to show that the potential impacts on human health and the environment, due to operation of the chemical agent disposal facilities, are acceptable. This paper describes and compares the types of air dispersion models, modeling input data requirements, modeling algorithms, and approaches used to satisfy the three environmental regulatory and risk management requirements listed above. Although this paper discusses only one industry (i.e., chemical demilitarization), the information it contains could help those in other industries who need to communicate to the public the purpose and objectives of each modeling analysis. It may also be useful in integrating the results of each analysis into an overarching summary of compliance and potential risks.