Analyzing construction safety through time series methods

The construction industry produces a large amount of data on a daily basis. However, existing data sets have not been fully exploited in analyzing the safety factors of construction projects. Thus, this work describes how temporal analysis techniques can be applied to improve the safety management of construction data. Various time series (TS) methods were adopted for identifying the leading indicators or predictors of construction accidents. The data set used herein was obtained from a large construction company that is based in Singapore and contains safety inspection scores, accident cases, and project-related data collected from 2008 to 2015. Five projects with complete and sufficient data for temporal analysis were selected from the data set. The filtered data set contained 23 potential leading indicators (predictors or input variables) of accidents (output or dependent variable). TS analyses were used to identify suitable accident predictors for each of the five projects. Subsequently, the selected input variables were used to develop three different TS models for predicting accident occurrences, and the vector error correction model was found to be the best model. It had the lowest root mean squared error value for three of the five projects analyzed. This study provides insights into how construction companies can utilize TS data analysis to identify projects with high risk of accidents.     

Sleep disorders and safety at work in industry workers

The present study investigated the relationship of sleep disturbances and safety at work in a population of 1502 industry workers. Workers complaining about their sleep, in particular those complaining about excessive daytime sleepiness, had significantly more work accidents, particularly repeated work accidents and significantly more sick days per work accident. These results suggest that sleep habits and sleep disturbances can provide valuable information regarding the worker accidents potential.     

State of Practice of Construction Site Safety in the USA

The construction industry has long been plagued with a high number of fatalities in the USA. Much safety improvements have been made after the USA Congress passed the Occupational Safety and Health Act in 1970. However, this industry still suffers from a disproportionately high rate of work-related fatalities in comparison to other industries. To provide a holistic view of current construction safety practices and corresponding performance, this paper reviews statistics of construction fatalities and their causes. It then presents efforts led to prevent work-related accidents and injuries by the federal safety agencies and the industry. Additionally, advantages and limitations of current practices in terms of construction safety have been discussed along with promotion of aspects in construction work environment.     

Investigating the challenges related to combining BIM and Last Planner System on construction sites

The construction industry is facing a gradual but important transformation toward more productivity and collaboration. In this framework, two major approaches are often cited in the literature as having the potential to improve the practices in the industry: Building Information Modeling (BIM) and Lean Construction. Several scientific studies have demonstrated the synergy of these two approaches and very recent research has reported positive results from the use of software applications as support for their implementation on construction sites. However, the stakes of such integration have been very little studied. This article presents the results of a research project conducted within a general contractor firm that decided to implement BIM and Last Planner System (LPS) on its construction sites. The research uses a four-stage action research approach, including the characterization of the research issue, the establishment of an action plan, its implementation and its evaluation. Compared to recent related studies, the research is less enthusiastic. While it highlights the need for new tools to improve production planning and control, it also points to a strong resistance to change by practitioners at the site. They emphasize the necessity for adequate pre-service training and the need for new resources that can work full-time on the ongoing training of site teams. In addition, some limitations of the tool lead workers to believe that it can quickly become a factor that slows down their daily work rather than improving it. Based on the advice of professionals, the paper formulates some recommendations to the industry, the researchers and the software developers.     

Applying data mining techniques to explore factors contributing to occupational injuries in Taiwan's construction industry

Construction accident research involves the systematic sorting, classification, and encoding of comprehensive databases of injuries and fatalities. The present study explores the causes and distribution of occupational accidents in the Taiwan construction industry by analyzing such a database using the data mining method known as classification and regression tree (CART). Utilizing a database of 1542 accident cases during the period 2000–2009, the study seeks to establish potential cause-and-effect relationships regarding serious occupational accidents in the industry. The results of this study show that the occurrence rules for falls and collapses in both public and private project construction industries serve as key factors to predict the occurrence of occupational injuries. The results of the study provide a framework for improving the safety practices and training programs that are essential to protecting construction workers from occasional or unexpected accidents.     

Failure analysis of connecting bolts in collapsed tower crane

The use of tower cranes can cause critical accidents during large building construction projects. Failure of the tower crane results in critical injuries to crane operators and other workers at the construction site. Issues that often cause the fatal collapse of tower cranes include the damage and fracture of the mast (or tower) and turntable parts, and the tower crane slewing‐unit‐support fleeing. Without systematic investigations and proper prevention procedures in place, this type of crane accident, which often leads to worker fatalities, will continue to occur. Therefore, more proactive, specialized and systematic research needs to be performed in terms of forensic engineering to minimize the occurrence of similar disasters. In this research, the tower crane collapse accidents are thoroughly investigated and the exact cause of the damaged crane parts is also identified using fractography and mechanical/chemical characterizations techniques, including visual inspections, field research, scanning electron microscopes and optical microscopes. Specifically, instrumented indentation technique is employed to evaluate the material properties, and energy spectrum analysis is used to determine the chemical characteristics. Based on thorough investigations, it has been identified that the connecting bolts of the tower crane are very vulnerable. It is recommended to improve the reliability of the bolts and to implement additional regulations to check their maintenance and safety. This research clearly provides guidance for investigating crane collapse accidents and contributes to the prevention of similar types of accidents. Several corrective actions and recommendations are suggested to reduce the risk of the tower crane failures.     

Behavior-based safety on construction sites: A case study

This work presents the results of a case study and describes an important area within the field of construction safety management, namely behavior-based safety (BBS). This paper adopts and develops a management approach for safety improvements in construction site environments. A rigorous behavioral safety system and its intervention program was implemented and deployed on target construction sites. After taking a few weeks of safety behavior measurements, the project management team implemented the designed intervention and measurements were taken. Goal-setting sessions were arranged on-site with workers’ participation to set realistic and attainable targets of performance. Safety performance measurements continued and the levels of performance and the targets were presented on feedback charts. Supervisors were asked to give workers recognition and praise when they acted safely or improved critical behaviors. Observers were requested to have discussions with workers, visit the site, distribute training materials to workers, and provide feedback to crews and display charts. They were required to talk to operatives in the presence of line managers. It was necessary to develop awareness and understanding of what was being measured. In the process, operatives learned how to act safely when conducting site tasks using the designed checklists. Current weekly scores were discussed in the weekly safety meetings and other operational site meetings with emphasis on how to achieve set targets. The reliability of the safety performance measures taken by the company's observers was monitored. A clear increase in safety performance level was achieved across all categories: personal protective equipment; housekeeping; access to heights; plant and equipment, and scaffolding. The research reveals that scores of safety performance at one project improved from 86% (at the end of 3rd week) to 92.9% during the 9th week. The results of intervention demonstrated large decreases in unsafe behaviors and significant increases in safe behaviors. The results of this case study showed that an approach based on goal setting, feedback, and an effective measure of safety behavior if properly applied by committed management, can improve safety performance significantly in construction site environments. The results proved that the BBS management technique can be applied to any country's culture, showing that it would be a good approach for improving the safety of front-line workers and that it has industry wide application for ongoing construction projects.     

The safety climate and its relationship to safety practices, safety of the work environment and occupational accidents in eight wood-processing companies

Employees continuously observe their work environment and the actions of their fellow workers and superiors, and they use such observations as a basis for the creation of cognitive models associated with safety. These models regulate their actions in the workplace and thus have an influence on safety. This study attempts to define the structure of the safety climate as perceived by workers and the correlations between the safety climate, on the one hand, and the safety practices of the company, the safety level of the work environment and occupational accidents on the other. The variables used in this study were the same as those employed in two previous Finnish safety climate studies carried out in the plywood industry, shipyards, the forestry industry, building construction and stevedoring. The safety climate was measured by means of a questionnaire. Workers from four sawmills, two plywood factories and two parquet plants participated. The total number of participants was 508 in 1990 and 548 in 1993. The variables formed four factors, whose contents and reliabilities closely resembled the results obtained in the earlier studies. These results indicate that the structure of the safety climate among Finnish workers is quite stable. The safety climate correlated both with the safety level of the work environment and with the safety practices of the company, but the correlation between the safety climate and the safety of the work environment was stronger. This result differs from those of the previous studies, in which the safety climate was defined specifically in terms of an individual’s perceptions of the safety practices of the company and of the behavior of other employees. The two safety climate factors that described a company’s attitudes to safety and its safety precautions correlated with the accident rates. The better the safety climate of the company was, the lower was the accident rate. Four companies with an accident rate below the average for the wood-processing industry had a better safety climate than four similar companies with an accident rate above the average.     

基于聚类算法的黔东南苗族鸟纹刺绣图案色彩特征研究

目的 以可量化和可视化的方式对黔东南苗绣中鸟图案的色彩特征和搭配关系进行探究和呈现,为苗族图案设计创新提供色彩规律借鉴,同时为民族色彩数据库的建立做准备。方法 运用中值滤波算法以及自适应纹理滤波算法对212张样本进行去噪平滑处理后,用K-Means聚类算法提取图像色彩,采用自动获取k值的方式确定色彩提取数量,以主色优先方式构建色彩网络模型。借助HSV色彩空间模型,以频数统计的方式从色相、饱和度、明度三个维度对不同绣法的色彩特征进行归纳。结论 研究结果以数据和图表形式表现苗绣中鸟纹的色彩搭配及规律情况,能够较为客观、准确地反映出苗绣鸟纹刺绣图案的色彩特征,研究结果可为设计师提供大量色彩搭配方案参考,提高设计师工作效率,对民族图案的再设计应用及非物质文化遗产传承再创新都具有重要价值。     

Employee engagement,boredom and frontline construction workers feeling safe in their workplace

Systems thinking is a philosophy currently prevalent within construction safety literature that is applied to understand and improve safety in sociotechnical systems. Among systems, the site-project organizational system is of particular interest to this paper. Using focus group and survey feedback research to learn about how safety incidents effect levels of construction workers engagement this paper reveals how a safety incident provides an opportunity to create a potential quality (productivity) upgrade within an organization. The research approach involved a qualitative study involving 27 frontline supervisors and a follow-up survey completed by 207 frontline workers in the Australian Asphalt and Pavement Industry. The focus group interviews supported the articulation of the concepts of tacit safety, explicit safety, situational awareness, foresight ability, practical intelligence and crew synergy. Our findings indicate that having regular shift changes and other job site workers being fatigued are influential on perceptions of tacit safety. An individual's foresight ability was found to be the most potent predictor of worker perceptions of work engagement. The paper explains that relatively small improvements in worker perceptions of safety can bring about significant improvements in employee engagement and productivity.     

An on-road study to investigate fatigue in local/short haul trucking

As a precursor to the present research, Hanowski et al. [FHWA Report no. FHWA-MC-98-029. Office of Motor Carriers, Federal Highway Administration, Washington, DC, 1998] conducted a series of focus groups in which local/short haul (L/SH) drivers provided their perspective on safety issues, including fatigue, in their industry. As a follow-up to the Hanowski et al. work, the effort presented here consisted of an on-road field study where in-service L/SH trucks were instrumented with data collection equipment. Two L/SH trucking companies and 42 L/SH drivers participated in this research. The analyses focused on determining if fatigue is an issue in L/SH operations. Of primary interest were critical incidents (near-crashes) where L/SH drivers were judged to be at fault. The results of the analyses indicated that fatigue was present immediately prior to driver involvement in at-fault critical incidents. Though it is difficult to determine with certainty why fatigue was present, the results suggest that drivers' off-hours behavior likely played a significant role in the fatigue experienced on the job. Another key finding of this research is that a small percentage of drivers were responsible for a majority of the critical incidents. This finding suggests that driver selection and monitoring could potentially improve safety in L/SH operations.     

Using biological motion to enhance the conspicuity of roadway workers

This study examined whether the conspicuity of road workers at night can be enhanced by distributing retroreflective strips across the body to present a pattern of biological motion (biomotion). Twenty visually normal drivers (mean age = 40.3 years) participated in an experiment conducted at two open-road work sites (one suburban and one freeway) at night-time. At each site, four road workers walked in place wearing a standard road worker night vest either (a) alone, (b) with additional retroreflective strips on thighs, (c) with additional retroreflective strips on ankles and knees, or (d) with additional retroreflective strips on eight moveable joints (full biomotion). Participants, seated in stationary vehicles at three different distances (80 m, 160 m, 240 m), rated the relative conspicuity of the four road workers. Road worker conspicuity was maximized by the full biomotion configuration at all distances and at both sites. The addition of ankle and knee markings also provided significant benefits relative to the standard vest alone. The effects of clothing configuration were more evident at the freeway site and at shorter distances. Overall, the full biomotion configuration was ranked to be most conspicuous and the vest least conspicuous. These data provide the first evidence that biomotion effectively enhances conspicuity of road workers at open-road work sites.     

The effects of error management climate and safety communication on safety: A multi-level study

Work in the construction industry is considered inherently dangerous, despite the technological improvements regarding the safety of work conditions and equipment. To address the urgent need to identify organizational predictors of safety performance and outcomes among construction workers, the present study examined multi-level effects of two important indicators of safety climate, namely contractor error management climate and worker safety communication, on safety behavior, injury, and pain among union construction workers. Data were collected from 235 union construction workers employed by 15 contractors in Midwest and Northwest regions of the United States. Results revealed significant main effects for safety communication and error management climate on safety behaviors and pain, but not on injuries. Our findings suggest that positive safety communication and error management climate are important contributors to improving workplace safety. Specific implications of these results for organizational safety research and practice are discussed.     

Integration of risk matrix and event tree analysis: a natural stone plant case

Machining has considerably increased with evolving technology and increasing demand in natural stone production facilities. Different types of accidents may occur in natural stone facilities during movement, dimensioning, cutting of blocks and surface processing. These accidents may be due to physical, chemical, ergonomic and mechanical conditions. Therefore, possible work accidents and occupational diseases should be investigated. In this study, an L-matrix analysis is conducted to analyze hazards and forecast risks in natural stone facilities. According to the L-matrix results, three major initiating events are identified. For each of these initiating events, event tree analysis is used to calculate risk scores. These initiating events are hoist rope fatigue and breaking, diamond wire fatigue and breaking, and electrical leakage due to old systems. These events and their results are classified according to the probabilities using event tree analysis.     

SAFETYNET--a European network for process safety

SAFETYNET is a European Thematic Network on Process Safety funded under the Brite-Euram Programme. The aim of this network is to reduce the time delay between research results and their practical use in industry in order to stimulate further development and adoption of technologies in the field of process safety. This is mainly done in areas related both to the safe operation of process plants and production facilities and to the prevention of accidents.     

Injury incidence rates in a paint company on rotating production shifts

Reports of work accidents and increased absence due to sickness among shift workers have suggested that their work performance and health are adversely affected by interference with the body's normal circadian or biological rhythm. Since the rotating shift is the most disruptive of the work regimens, an investigation was undertaken of the reportable occupational injuries of 1700 paint production and associated employees of one company working only on rotating shift. Their annual accident incidence rates averaged over 10 years were compared to the average annual rate reported by the Department of Labor for the entire United States paint manufacturing industry representing predominately day and non-rotating shift workers. The significance of the hour of the accident incidence rates was tested by chi-square statistics using loglinear models appropriate for null hypotheses that assume no effect due to shift work. The incidence rates of the company studied were lower than those of the U.S. paint industry, suggesting work safety practices uniquely related to the company studied may have predominated. Within the company, however, some time-of-day and circadian effects were indicated by an increased rate of accidents on the night shift, particularly during the last 3 h of the shift.     

Analysis of factors influencing safety management for metro construction in China

With the rapid development of urbanization in China, the number and size of metro construction projects are increasing quickly. At the same time, and increasing number of accidents in metro construction make it a disturbing focus of social attention. In order to improve safety management in metro construction, an investigation of the participants’ perspectives on safety factors in China metro construction has been conducted to identify the key safety factors, and their ranking consistency among the main participants, including clients, consultants, designers, contractors and supervisors. The result of factor analysis indicates that there are five key factors which influence the safety of metro construction including safety attitude, construction site safety, government supervision, market restrictions and task unpredictability. In addition, ANOVA and Spearman rank correlation coefficients were performed to test the consistency of the means rating and the ranking of safety factors. The results indicated that the main participants have significant disagreement about the importance of safety factors on more than half of the items. Suggestions and recommendations on practical countermeasures to improve metro construction safety management in China are proposed.     

Speed reduction on through roads in Nordrhein-Westfalen.

The paper describes a program of experiments for speed reduction on 28 through roads in Nordrhein-Westfalen. In the process, different measures of construction, design, and traffic control were examined to determine their usefulness to reduce speed and to improve road safety. The need for systematic evaluation of a catalogue of measures partly resulted in unsatisfactory design conceptions for the through roads. The evaluation of the effects of the program has been carried out by use of before-and-after-studies of large extent. The speed measurements show that a distinct speed reduction can be obtained only from selected physical improvements. Measures based on optical effects and traffic signs were found to have very little effect on vehicle speeds. Furthermore, in light of the relatively small number of accidents that occur on the selected facilities, it was not possible to establish the beneficial impact of each specific control measure with statistical certainty. However, the results of the experiment have had an influence on the current definition of new design standards for main urban streets in Germany.     

Management of climatic heat stress risk in construction: A review of practices,methodologies, and future research

Climatic heat stress leads to accidents on construction sites brought about by a range of human factors emanating from heat induced illness, and fatigue leading to impaired capability, physical and mental. It is an occupational characteristic of construction work in many climates and the authors take the approach of re-engineering the whole safety management system rather than focusing on incremental improvement, which is current management practice in the construction industry. From a scientific viewpoint, climatic heat stress is determined by six key factors: (1) air temperature, (2) humidity, (3) radiant heat, and (4) wind speed indicating the environment, (5) metabolic heat generated by physical activities, and (6) “clothing effect” that moderates the heat exchange between the body and the environment. By making use of existing heat stress indices and heat stress management processes, heat stress risk on construction sites can be managed in three ways: (1) control of environmental heat stress exposure through use of an action-triggering threshold system, (2) control of continuous work time (CWT, referred by maximum allowable exposure duration) with mandatory work-rest regimens, and (3) enabling self-paced working through empowerment of employees. Existing heat stress practices and methodologies are critically reviewed and the authors propose a three-level methodology for an action-triggering, localized, simplified threshold system to facilitate effective decisions by frontline supervisors. The authors point out the need for “regional based” heat stress management practices that reflect unique climatic conditions, working practices and acclimatization propensity by local workers indifferent geographic regions. The authors set out the case for regional, rather than international, standards that account for this uniqueness and which are derived from site-based rather than laboratory-based research.     

A systematic review of safety violations in industry

It is widely known that intentional non-malevolent violations of safety procedures and norms occur and evidence shows that safety violations can increase the risk of accidents. However, little research about the causes of these violations in work settings exists. To help shed light on the causes, this paper systematically reviews the empirical causes of safety violations in industry. Electronic database literature searches were performed to identify relevant articles published prior to January 1, 2007. Thirteen articles met the inclusion criteria and 57 different variables were examined as predictors of safety violations. Study settings were healthcare delivery, commercial driving, aviation, mining, railroad, and construction. The predictors were categorized into individual characteristics, information/education/training, design to support worker needs, safety climate, competing goals, and problems with rules. None of the reviewed studies examined whether violations can improve system performance or safety. Methodological suggestions and a macroergonomic framework are offered for improving future studies of the epidemiology of safety violations.