Monitoring the location of resources on large scale, congested, outdoor sites can be performed more efficiently with vision tracking, as this approach does not require any pre-tagging of resources. ...However, the greatest impediment to the use of vision tracking in this case is the lack of detection methods that are needed to automatically mark the resources of interest and initiate the tracking. This paper presents such a novel method for construction worker detection that localizes construction workers in video frames. The proposed method exploits motion, shape, and color cues to narrow down the detection regions to moving objects, people, and finally construction workers, respectively. The three cues are characterized by using background subtraction, the histogram of oriented gradients (HOG), and the HSV color histogram. The method has been tested on videos taken in various environments. The results demonstrate its suitability for automatic initialization of vision trackers.
► We propose a method of detecting construction workers in video frames. ► The method exploits motion, shape, and color features to characterize workers. ► Color features enable the method to differentiate workers from ordinary people. ► Experiments resulted in 99.0% precision. ► Workers were detected within 0.67s after their first appearance.
The study is devoted to the examination of the function of the so called reverse charge mechanism in the field of construction works. This mechanism is in force from Jan 1, 2017. The analysis is ...based on the example of a model in which the contractor performs part of the works on his/her own, and s/he commissions the remaining part of the works to other entities. The study is also an attempt to establish whether it is possible to determine on the grounds of available data that an extension of the application of the regulations of reverse burden mechanism contributed to the improvement of tax collection.
A literature review revealed several major shortcomings in the analysis of construction equipment operations data, for example, the lack of using realistic or real-time positioning data that can feed ...into an equipment operations analysis or simulation model. This paper presents technology and algorithms that have the potential in aiding the automated assessment of construction site equipment operations. Utilizing commercially available low-cost global positioning system (GPS) devices enables the continuous data logging of equipment location in addition to simultaneously recording timestamps. However, before any such spatio-temporal equipment data can be reliably collected on construction sites, the error rate of the GPS devices had to be evaluated. Data analysis methods and rules for monitoring construction site equipment operations and activity were then defined. A detailed software interface was finally created that allows a user to set, analyze, and visualize several important equipment parameters towards achieving the goal of creating more realistic equipment operation analysis and potential for inclusion in simulation models. Results from field experiments show that the developed technology is able to identify and track equipment activity- and safety-related information automatically for job site performance and layout decision making, respectively. The presented work will aid construction project managers in making better decisions to plan, manage, and control equipment-related work tasks on construction sites.
Display omitted
► Continuous data collection in construction equipment operation is lacking detail. ► GPS data loggers can collect reliable location tracking data for further analysis. ► A software user interface allows detection and visualization of active job site areas. ► Information to equipment cycles, hours of operation, and proximity can be collected. ► Data can be used in application, e.g., construction equipment simulation and safety.
Efficient and effective construction progress tracking is critical to construction management. Current manual tracking methods are time consuming and/or error prone. Three dimensional (3D) laser ...scanners are being investigated in the construction industry and have shown potential for supporting progress tracking. However, their full potential has not yet been achieved. The reason may be that commercial software packages are still too complicated for processing scanned data. Methods have however been developed for the automated recognition of project 3D CAD model objects in site laser scans. A novel system is thus described herein that combines 3D object recognition technology with schedule information into a combined 4D object oriented progress tracking system. This system is tested on a comprehensive field database acquired during the construction of the Engineering V Building at the University of Waterloo. It demonstrates a degree of accuracy for automated progress tracking that meets or exceeds typical manual performance.
► 3D Laser scans are fused with 4D models to automate construction progress control. ► The system is tested with the data collected from a concrete building construction. ► The results indicate the importance of planning for scanning. ► Using updated schedules gives better progress estimation results.
Accurate construction progress measurement has been shown to be critical to the success of a building project. However, the methods of automated construction progress measurement proposed in previous ...studies have certain limitations because of incomplete data sets. The main objective of this research was to develop an accurate, essentially fully automated method for construction progress measurement using a 4D BIM in concert with 3D data obtained by remote-sensing technology. The proposed method consists of three phases: alignment of the as-built data with the as-planned model, matching of the as-built data to information in the BIM, and revision of the as-built status. The accuracy of the proposed construction progress measurement method was validated using 3D data obtained from an actual construction site, thereby demonstrating that construction progress can be effectively measured. The results of the proposed progress measurement methodology can be used as input for construction progress visualization and schedule updating.
► This study presented a fully automated method for measuring construction progress. ► The method uses a 4D BIM and 3D data obtained by remote-sensing technology. ► The accuracy of the method was validated on a four-floor building under construction. ► The construction progress can be measured accurately even with an incomplete 3D data. ► The method can be used for construction progress visualization and schedule updating.
Over six hundred construction worker deaths occurred in the United States during the inclusive years of 2004 to 2006 that were related to construction equipment and contact collisions. This paper ...presents findings about emerging radio frequency (RF) remote sensing and actuating technology that can improve construction safety by warning or alerting workers-on-foot and equipment operators in a pro-active real-time mode once equipment gets too close in proximity to unknown or other equipment. A review is provided on the background and importance of safety related to various pieces of construction equipment. Pro-active real-time proximity and alert technology for daily construction operations is introduced to solve this problem. Results of various field experiments that tested the proximity and alert technology are presented. A discussion follows on how such technology can improve objective construction site safety data collection and lead to more effective construction workforce safety training and education.
As digital technologies become widely used in designing buildings and infrastructure, questions arise about their impacts on construction safety. This review explores relationships between ...construction safety and digital design practices with the aim of fostering and directing further research. It surveys state-of-the-art research on databases, virtual reality, geographic information systems, 4D CAD, building information modeling and sensing technologies, finding various digital tools for addressing safety issues in the construction phase, but few tools to support design for construction safety. It also considers a literature on safety critical, digital and design practices that raises a general concern about ‘mindlessness’ in the use of technologies, and has implications for the emerging research agenda around construction safety and digital design. Bringing these strands of literature together suggests new kinds of interventions, such as the development of tools and processes for using digital models to promote mindfulness through multi-party collaboration on safety.
Today, many construction operations have incorporated automated equipment, means, and methods into their regular practises. Although adaption of automation in the building construction sector has ...been slow, principles of industrial automation are applicable to this domain, both to building construction, civil engineering, and to prefabrication of construction components. Improved sensor technologies and the widening use of the Building Information Modeling (BIM) will offer new possibilities to cover various needs and operations taking place throughout the building life cycle. These can play a key role in future construction automation. This paper provides a survey for potential sensor technologies for building construction automation, highlighting their potential also with contributions from robotics. The paper carries out the survey from the viewpoints of building construction phases.
The construction industry around the globe has been increasingly advocated to utilize prefabrication to minimize waste, thereby alleviating associated negative impacts on environment and the society. ...Previous studies have reported on waste reduction potential from adopting prefabrication in various economies including Hong Kong. A significant shortcoming of these studies; however, is the neglect of the upstream processes of prefabrication including the manufacturing and transportation of components, which causes construction waste as well. To date it is still unclear how this portion of construction waste is generated and quantified. The issues are even more complicated in Hong Kong where components are manufactured in the offshore Pearl River Delta Region (PRDR) of mainland China and transported across the border to construction sites in Hong Kong. Against the theoretical backdrop of whole life cycle thinking, the aim of this study is to empirically investigate the manufacture and cross-border transportation processes, thereby to assess the waste reduction potentials of using prefabrication in construction. It does so by conducting three in-depth case studies with selected PRDR prefabrication factories. A hybrid of research methods are employed in the study. It is found that the waste generation rate in the upstream processes of offshore prefabrication is around 2% or lower by weight. This proves the orthodox that prefabrication in a factory environment is more conducive to waste reduction than the traditional cast in-situ construction manner. However, transporting the components adds cost and simultaneously increases the risk of waste generation. This study provides insights into understanding construction waste reduction through offshore prefabrication from a holistic view.
AbstractThe construction industry has experienced a great deal of safety improvement after the Congress passed the Occupational Safety and Health Act in 1970. In the last twenty years, improvements ...have been made largely due to safety interventions that exceed compliance with government regulations. Researchers have long attempted to identify the most effective safety programs. However, studies in the past focused only on a small subset of potential injury-prevention options. In addition, to date, there has yet to be a study that documents a comprehensive list of safety strategies implemented by industry-leading companies. This research addresses this knowledge gap by creating a comprehensive list of construction-safety strategies from relevant literature and supplementing it with input from an expert panel. Once the strategies were identified (n=104), the research team conducted interviews with representatives from 57 projects in the United States to determine which strategies were implemented on each project and the project’s recordable injury rate (RIR). The data were then analyzed to determine the total proportion of potential strategies implemented and examine the relationship between each strategy and the RIR. The results reveal that 14 strategies differentiate safety performance (P>0.05) and that 22 strategies were implemented by 100% of the sample projects. The implications are that the 22 practices implemented in all projects can now be considered a foundation of a safety program, and the 14 differentiators are the keys to improved safety performance.
PDF
