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Effective crane management is imperative to ensure that construction projects are completed on time, within budget, and with a high degree of safety. Prior research on crane management has mostly focused on satisfaction of spatial constraints and minimization of overlapping areas for operation of multiple cranes. However, little attention has been paid to maximizing concurrent crane operations that justify interdependencies among paths, cranes, overlapping areas, and tasks. To overcome this limitation, this study aims to improve multicrane layout planning comprehensively by accounting for various crane operational and managerial parameters (testing various crane specifications and layouts along with alternative cranes, motion paths, and task execution queues) and their parametric interdependencies. Results of the study on an actual construction site demonstrated the improved ability of the developed model in terms of efficiency compared with existing approaches. Therefore, this research anticipates assisting project managers and practitioners with a model for efficient decision making regarding site layout plans for operation of multiple tower cranes. [ABSTRACT FROM AUTHOR]

The nature of an indoor construction site is dynamic and complex. This characteristic becomes even more evident when a multitude of interactions among workers, equipment, and materials exists. To assist various operations of construction, which are dynamic and complex in nature, previous research explored sensing technologies to discover advanced approaches to supporting construction operations. In particular, many researchers have focused on investigating the tracking of construction resources over the past several years. Despite the previous research efforts in radio-signal-strength-indication (RSSI)-based tracking systems, signal interference such as signal degradations, occlusions, obstructions, and multipath effects created by a complex and dynamic construction environment has not been clearly discussed. Furthermore, fundamental understanding of issues associated with signal interference is limited. This research aims to reduce the gap in knowledge of the RSSI-based tracking system when it is used in a highly noisy environment like a dynamic, complex, and large indoor construction site. This paper presents the development of a new probabilistic local search (PLS) algorithm using Bluetooth low energy network technology. The PLS is assessed with respect to accuracy, reliability, and robustness. Two conventional positioning methods are subjected to the same tests as a benchmark for comparison. The results indicate that PLS outperforms the other conventional methods when the signal interference is high and performs comparably when the signal interference is minimal. [ABSTRACT FROM AUTHOR]

The planning of tower crane operations is a complex process that has significant impact on the time, cost, productivity, and safety of construction projects. This complexity pertains to the involvement of multiple tasks, cranes, and material supply locations, as well as their interactions with each other. Overlapping areas between cranes also lead to increased collision possibilities, resulting in additional crane operation complexity. To increase crane operation productivity while maintaining safety, proper linkage between tasks, cranes, and material supply locations is important. Past research has linked tasks to supply points based on minimized individual task operating time, such that a task is linked to a supply point that provides the minimum amount of time for task completion. This approach may not be as efficient as possible for construction sites with overlapping crane areas, as it may increase total project time although time for each individual task is at a minimum. To address this concern, this research develops a Java-based, agent-based modeling (ABM) simulation tool to investigate the effects of dynamic supply selection on crane efficiency. This ABM applies a dynamic supply selection system and tests numerous scenarios to ensure the most efficient linkage between tasks, cranes, and supply locations. To evaluate the capabilities of the developed method, it has been applied to a real-world construction project. The results of this case study indicate that effective crane operation planning, conducted through dynamic supply location selection, with respect to tasks and cranes, can have a significant impact on productivity and the total schedule time of crane tasks. • A Java-based agent-based simulation was devised to model crane operations in construction sites. • A dynamic linkage system was developed to investigate the linkage among cranes, tasks, and supply locations. • This study revealed the effects of dynamic supply selection on crane efficiency with a focus on cranes overlapping areas. • A multitude of comprehensive simulations were conducted based off of an actual project to evaluate the method. • A benchmark comparison showed evidence of improvement in total operation time and crane utilization rates. [ABSTRACT FROM AUTHOR]

The application of tactile-based wearable devices to assist in navigation for people with low sight/low memory has demonstrated the feasibility of using such devices as a means of communication. Accordingly, a previous study in construction research investigated various parameters of tactile signals to develop a communicable system for potential application in construction hazard communication. However, the nature of construction limits the application of such devices to the body of construction workers, and it is important to understand sensor design parameters for improved communication, which has not been given significant attention yet. Therefore, this study aims to determine key design factors such as the number of motors, spacing between sensors and the layout of a tactile sensory system to be used for communicating construction hazards to workers. For this purpose, this study focused on identifying the number of motors based on extensive literature and the problem of construction safety as to hazard communication, determining the arrangement that allowed for effective delivery and perception of information with minimum effort. The researchers conducted two experimental studies: First, to determine the minimum spacing between vibration motors that allows for the identification of each individual motor with high accuracy; and second, to determine the layout of motors that is suitable for effective communication of multiple types of information. More importantly, the tactile-sensor configuration identified from this study allows the workers to learn the signal patterns easily in order to identify multiple types of information related to hazards. Using such a communication system on construction sites will assist in transmitting hazard-related information to workers, and thus, protect the lives of workers. Such wearable technologies enable the detection of individual-level hazards and prevent worker fatalities and severe injuries. [ABSTRACT FROM AUTHOR]