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Work-related musculoskeletal disorders constitute a severe problem in the construction industry. Workers' lower backs are often affected by heavy or repetitive lifting and prolonged awkward postures. Exoskeletal interventions are effective for tasks involving manual lifting and repetitive movements. This study aims to examine the potential of a postural-assist exoskeleton (a passive exoskeleton) for manual material handling tasks.

From an experimental observation of participants, the effects of postural-assist exoskeleton on tasks and workers were measured. Associated benefits of the exoskeleton were assessed through task performance, range of motion and discomfort.

Findings suggest that the exoskeleton influenced discomfort significantly, however range of motion decreased with lifting tasks. The reduced back flexion and increased hip flexion were also indicatives of the participants' responsiveness to the feedback from the exoskeleton. In addition, task completion time increased by 20%, and participants' back pain did not reduce.

The work tasks were performed in a controlled laboratory environment and only wearable inertia measurement units (IMUs) were used to assess the risk exposures of the body parts.

This study opens a practical pathway to human-exoskeleton integration, artificial regeneration or enablement of impaired workforce and a window toward a new order of productivity scaling. Results from this study provide preliminary insights to designers and innovators on the influence of postural assist exoskeleton on construction work. Project stakeholders can be informed of the suitability of the postural assist exoskeletons for manual material handling tasks.

Little has been reported on the benefits and impact of exoskeletons on tasks' physical demands and construction workers' performance. This study adds value to the existing literature, in particular by providing insights into the effectiveness and consequences of the postural-assist exoskeleton for manual material handling tasks.

The physically-demanding and repetitive nature of construction work often exposes workers to work-related musculoskeletal injuries. Real-time information about the ergonomic consequences of workers' postures can enhance their ability to control or self-manage their exposures. This study proposes a digital twin framework to improve self-management ergonomic exposures through bi-directional mapping between workers' postures and their corresponding virtual replica.

The viability of the proposed approach was demonstrated by implementing the digital twin framework on a simulated floor-framing task. The proposed framework uses wearable sensors to track the kinematics of workers' body segments and communicates the ergonomic risks via an augmented virtual replica within the worker's field of view. Sequence-to-sequence long short-term memory (LSTM) network is employed to adapt the virtual feedback to workers' performance.

Results show promise for reducing ergonomic risks of the construction workforce through improved awareness. The experimental study demonstrates feasibility of the proposed approach for reducing overexertion of the trunk. Performance of the LSTM network improved when trained with augmented data but at a high computational cost.

Suggested actionable feedback is currently based on actual work postures. The study is experimental and will need to be scaled up prior to field deployment.

This study reveals the potentials of digital twins for personalized posture training and sets precedence for further investigations into opportunities offered by digital twins for improving health and wellbeing of the construction workforce.

Fall accidents can cause casualties and economic losses in the construction industry. Fall portents, such as loss of balance (LOB) and sudden sways, can result in fatal, nonfatal or attempted fall accidents. All of them are worthy of studying to take measures to prevent future accidents. Detecting fall portents can proactively and comprehensively help managers assess the risk to workers as well as in the construction environment and further prevent fall accidents.

This study focused on the postures of workers and aimed to directly detect fall portents using a computer vision (CV)-based noncontact approach. Firstly, a joint coordinate matrix generated from a three-dimensional pose estimation model is employed, and then the matrix is preprocessed by principal component analysis, K-means and pre-experiments. Finally, a modified fusion K-nearest neighbor-based machine learning model is built to fuse information from the x, y and z axes and output the worker's pose status into three stages.

The proposed model can output the worker's pose status into three stages (steady–unsteady–fallen) and provide corresponding confidence probabilities for each category. Experiments conducted to evaluate the approach show that the model accuracy reaches 85.02% with threshold-based postprocessing. The proposed fall-portent detection approach can extract the fall risk of workers in the both pre- and post-event phases based on noncontact approach.

First, three-dimensional (3D) pose estimation needs sufficient information, which means it may not perform well when applied in complicated environments or when the shooting distance is extremely large. Second, solely focusing on fall-related factors may not be comprehensive enough. Future studies can incorporate the results of this research as an indicator into the risk assessment system to achieve a more comprehensive and accurate evaluation of worker and site risk.

The proposed machine learning model determines whether the worker is in a status of steady, unsteady or fallen using a CV-based approach. From the perspective of construction management, when detecting fall-related actions on construction sites, the noncontact approach based on CV has irreplaceable advantages of no interruption to workers and low cost. It can make use of the surveillance cameras on construction sites to recognize both preceding events and happened accidents. The detection of fall portents can help worker risk assessment and safety management.

Existing studies using sensor-based approaches are high-cost and invasive for construction workers, and others using CV-based approaches either oversimplify by binary classification of the non-entire fall process or indirectly achieve fall-portent detection. Instead, this study aims to detect fall portents directly by worker's posture and divide the entire fall process into three stages using a CV-based noncontact approach. It can help managers carry out more comprehensive risk assessment and develop preventive measures.

Concrete workers perform physically demanding work in awkward postures, exposing their backs to musculoskeletal disorders. Back-support exoskeletons are promising ergonomic interventions designed to reduce the risks of back disorders. However, the suitability of exoskeletons for enhancing performance of concrete workers has not been largely explored. This study aims to assess a passive back-support exoskeleton for concrete work in terms of the impact on the body, usability and benefits of the exoskeleton, and potential design modifications.

Concrete workers performed work with a passive back-support exoskeleton. Subjective and qualitative measures were employed to capture their perception of the exoskeleton, at the middle and end of the work, in terms of discomfort to their body parts, ease of use, comfort, performance and safety of the exoskeleton, and their experience using the exoskeleton. These were analyzed using descriptive statistics and thematic analysis.

The exoskeleton reduced stress on the lower back but caused discomfort to other body parts. Significant correlations were observed between perceived discomfort and usability measures. Design modifications are needed to improve the compatibility of the exoskeleton with the existing safety gears, reduce discomfort at chest and thigh, and improve ease of use of the exoskeleton.

The study was conducted with eight concrete workers who used the exoskeleton for four hours.

This study contributes to existing knowledge on human-wearable robot interaction and provides suggestions for adapting exoskeleton designs for construction work.

This chapter discussed the implementation of the digital twin (DT) idea into construction. Through the adoption of DTs into construction practices, construction professionals have been able to project an identical virtual concept of sections of the project execution right from the onset. In the introduction and discussing of its origin, the DT was further assessed about its applications in construction beneficial in enhancing project delivery. Other sections like barriers, drivers and benefits of the DT in construction summarised what this chapter represents in terms of discussing the new involvement of digital tools in construction execution, management and sustainability.

Work on construction sites involves individuals with diverse character, temperament,age, physical strength, culture, religion and experience level. A good number of these individuals are also alleged to involve themselves in substance and alcohol abuse due to the physically demanding nature of their work. These could promote the prevalence of violence on construction sites which could in turn affect safety on construction sites. However, there is a lack of empirical insight into the effect of violent behaviour and unsafe behaviour on construction sites. This study therefore pioneers an empirical inquiry into the relationship between violent behaviour and unsafe behaviour on construction sites.

Seventeen violent behaviours and 15 unsafe behaviours were measured on 12 construction sites among 305 respondents using a structured questionnaire. A total of 207 valid questionnaire responses were collected from site workers. Partial least square–structural equation modelling (PLS-SEM) technique was used to examine the relationship between violent behaviour and unsafe behaviour.

The results indicate that there is a significant positive relationship between violent behaviour and unsafe behaviour on construction sites.

The findings from this study provide valuable insight into a less investigated dimension of the problem of construction site safety management. A focus on attitudinal issues such as how workers relate toward others and toward self should be an important consideration in safety improvement interventions on construction sites.

This study aims to observe the impact of peripheral vision on construction safety. The study further intends to create awareness of eye diseases in construction safety, an important root cause for most construction-related hazards and accidents.

This study focuses on the impact of peripheral vision in terms of construction site safety. Experiments were conducted with construction employees with different qualifications, ages, expertise and previous safety training experience. The experiments were conducted with an experiment set consisting of a tangent screen to measure the peripheral angle of the participants. The study measured peripheral vision, which helped determine the vision field accordingly. In this context, a total of 32 participants were investigated in terms of their peripheral visual angle and the field of vision. The data collected were analyzed in terms of several statistical tests such as One-Sample t-test, multivariate ANOVA and multiple linear regression.

The results of the study indicated that there are significant differences in peripheral vision in terms of age of participants, work qualification, work experience, area of expertise and previous safety training experience. The study further revealed that most of the participants failed to satisfy both OSHA requirements about peripheral vision, and normal limits defined in the previous literature. The study further implies that participants, who reported previous sight problems or eye diseases are more vulnerable to construction site accidents.

Construction site safety remains a major concern for most construction companies despite the latest developments in technology. Several companies are struggling with poor safety performance, occupational injuries and illnesses, and work-related accidents resulting in fatalities. However, the root causes behind several construction accidents are still vague due to different dynamics in the construction industry. Among these root causes, poor sight, vision and or eye diseases constitute an important part. Hence, the study provides empirical evidence with the workers checked for eye health to help policymakers and industry practitioners in terms of developing awareness for eye-related injuries and accidents and review their safety programs accordingly.

Over the past several decades, the need for safety on offshore oil platforms has attracted significant attention from all its stakeholders. This paper seeks to present a mathematical model that could be used to control unsafe conditions on oil platforms.

The model is based on the intuitive notion of safety underlying practices on an offshore platform. The theory of control system combines the human/operator factor gain, maintenance function effectiveness, the component safety quality assurance system, and the safety measurement system in a holistic manner to attain a controlled status of the oil platform.

It is observed that these components relate in a mutually interlinked system that guarantees maximum safety control if all the components are holistically managed.

Practically, the control of an offshore oil platform guarantees the lives and properties of those who utilize the oil platform.

The work is perhaps the first to advance a model of safety on oil platforms with the use of control systems. The work would be of value to safety managers, employees of oil companies and researchers interested in the control of accidents on oil platforms.

This paper presents Quick Changeover Design (QCD), which is a structured methodological approach for Original Equipment Manufacturers to drive and support the design of machines in terms of rapid changeover capability.

To improve the performance in terms of set up time, QCD addresses machine design from a single-minute digit exchange of die (SMED). Although conceived to aid the design of completely new machines, QCD can be adapted to support for simple design upgrades on pre-existing machines. The QCD is structured in three consecutive steps, each supported by specific tools and analysis forms to facilitate and better structure the designers' activities.

QCD helps equipment manufacturers to understand the current and future needs of the manufacturers' customers to: (1) anticipate the requirements for new and different set-up process; (2) prioritize the possible technical solutions; (3) build machines and equipment that are easy and fast to set-up under variable contexts. When applied to a production system consisting of machines subject to frequent or time-consuming set-up processes, QCD enhances both responsiveness to external market demands and internal control of factory operations.

The QCD approach is a support system for the development of completely new machines and is also particularly effective in upgrading existing ones. QCD's practical application is demonstrated using a case study concerning a vertical spindle machine.

Construction safety has been a long-term problem in the development of the construction industry. An increasing number of smart construction sites have been designed using different techniques to reduce injuries caused by construction accidents and achieve proactive risk control. However, comprehensive smart construction site safety management solutions and applications have yet to be developed. Thus, this study proposes a smart construction site framework for safety management.

A safety management system based on a cyber-physical system is proposed. The system establishes risk data synchronization mapping between the virtual construction and physical construction sites through scene reconstruction design, data awareness, data communication and data processing modules. Personnel, mechanical and other risks on site will be warned and controlled.

The results of the case study have proved the management benefits of the system. On-site workers gradually realized that they should enter the construction site based on the standard process. And the number of people close to the construction hazard areas decreased.

There are some limitations in the technology of smart construction site. The modeling speed can be faster, the data collection can be timelier, and the identification of unsafe behavior can be integrated into the system. Construction quality and efficiency issues in a virtual construction site will also be solved in further research.

In this paper, this system is actually applied in the mega project management process. More practical projects can use the management ideas and method of this paper to ensure on-site safety.

This study is among the first attempts to build a complete smart construction site based on CPS and apply it in practice. Personnel, mechanical, components, environment information will be displayed on the virtual construction site. It will greatly promote the development of the intellectualized construction industry in the future.