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Mobile cranes are essential for transporting heavy materials at construction sites, but their operation carries significant safety risks, particularly due to the potential for overturning accidents. These accidents can be classified into two main categories: mechanical accidents, which are caused by factors such as outrigger failure, excessive load weight, and operator skill, and environmental accidents, which arise from ground subsidence due to groundwater and sinkholes. While numerous studies have addressed the causes and prevention of mechanical accidents, there has been a lack of research focusing on the prevention of environmental accidents. This study presents the development of an Electrical Resistivity Measurement System (ERMS) designed to prevent overturning accidents caused by ground subsidence at mobile crane work sites. The ERMS, mounted on a mobile crane, continuously monitors the ground conditions in real time and predicts the likelihood of ground subsidence to prevent accidents. Unlike typical buried electrode methods, the proposed system features a foldable electrode mechanism and a water supply device, thereby making installation and removal more efficient. Furthermore, it uses a ground stability determination algorithm that qualitatively assesses soft ground conditions, which are the primary cause of ground subsidence. The performance of the ERMS was validated through comparisons with commercial equipment, and its applicability was further confirmed through field tests conducted at mobile crane installations. The ERMS is expected to significantly reduce the risk of accidents caused by ground subsidence during mobile crane operations and to contribute to enhancing overall safety in construction environments. [ABSTRACT FROM AUTHOR]

Summary: Telescopic truck crane is an under‐actuated mechanical system with three actuators controlling five outputs. Its complex structure, shape variation, uncertain parameters, elastic cables, and viscoelastic cylinders are great challenges in control design. This article proposes two adaptive robust controllers for such cranes. A control core assures robustness based on back‐stepping and Lyapunov stability. The adaptation is achieved by employing model‐reference adaptive and self‐tuning control approaches. Thus, the benefits of these adaptive techniques are introduced into the control systems. The application to a practical crane shows the effectiveness of the proposed controllers. The crane has robustness and adaptation despite the elasticity and friction of the load‐carrying cable, the viscoelasticity of the cylinders, the variation of crane parameters, and the presence of winds. Comprehensive comparison indicates the state of the art and the shortcomings of the control systems. [ABSTRACT FROM AUTHOR]

Precise luffing of payload in mobile cranes is a crucial part of material handling and safety in industrial operations. Explosive ordnance disposal uses a bomb disposal robot to safely disable explosive devices at a safe distance. This robot is a mobile jib crane type with a gripper as an end effector instead of the typical suspension cable with a hook. The common challenge of this crane type is the arm/jib movement sensitivity with respect to tip-over stability of the crane body. This is directly influenced by the payload and constrained by the degree of freedom. This paper presents a control strategy of the joint for luffing such that the back wheels remain in contact with the surface ground and avoid bucking at any given instance of weight change in the payload. Fuzzy logic was applied to control the motor torque and luffing angle of the arm in response to the load and gripper opening size to maintain the tip-over stability margin at the highest value possible. The response curves at different configurations of the two input signals were also analyzed based on the rules set to determine its precision with respect to the expected response curve. [ABSTRACT FROM AUTHOR]

The emerging advances in deep learning and computer vision have enabled traditional cloud-based decision-making through edge computing with artificial intelligent internet of things (AIoT) image sensors (AIoT-IS). As a result, the timeliness and security of image recognition can be obtained. This study aims to develop an AIoT-IS-based smart safety control device for construction sites ("SmartCon" hereafter) for the operations of mobile cranes. The research is carried out to include the definition of hazardous control areas and the identification of unsafe scenarios for crane operations, the development of an intelligent prototype system for the safety control of lifting operations, system application demonstrations, and the evaluation of effectiveness. It is intended to assist labor inspection agencies and industry practitioners with a tool for monitoring lifting operations. The results of two empirical field tests show that the proposed SmartCon improves the safety monitoring of the operation of the machine through the real-time response to the identified potential risks on construction sites. [ABSTRACT FROM AUTHOR]

The growing prevalence of modular construction, while it offers benefits in terms of productivity and sustainability, has led to increased use of heavy mobile cranes and related resources on construction sites. One significant resource associated with crane use is the crane mat, which offers practical mobile crane ground support against poor soil-bearing capacity. Due to increased use of crane mats, crane mat layout plans/drawings have become increasingly significant in today's construction industry. The present work describes an automated crane mat optimization framework for preparing crane mat layout plans/drawings built on an agent-based greedy algorithm and reinforcement learning. The proposed framework employs these approaches to achieve the maximum area with the minimum number of crane mats. The proposed framework is found to decrease the time required for preparing a crane mat layout plan/drawing (approximately 97% time saving) with more uniform and efficient crane mat planning outcomes (approximately 63% crane mat material reduction). The research presented in this manuscript examined the largely unexplored topics of crane mat layout optimization and layout preparation, proposing an agent-based greedy algorithm and reinforcement learning (RL) approach for automated crane mat layout optimization as an innovative approach to developing sustainable crane mat layouts. This approach takes into account the site constraints and can be applied to mitigate crane mat crowding on construction sites. Crane mat optimization is applied using both methods (greedy and RL) to achieve the maximum area covered with the minimum number of crane mats used. The results demonstrate that the practitioner time spent preparing a crane mat layout plan/drawing can be reduced considerably, with more uniform and cost-effective crane mat optimization outcomes. Another outcome of this research is that developed approaches reduce the crane mat requirements compared with the outputs generated by the manual approach, thereby reducing the CO2 emissions associated with crane mat manufacturing and usage. [ABSTRACT FROM AUTHOR]

A sustainable future is required for precast concrete structures, and the reuse of concrete elements will be an essential part of the solution. Design for disassembly is currently conducted with costly and time-consuming mechanical joints. Now, mortar joints with much weaker mortar types are proposed for new buildings, enabling easier disassembly by new methods: removal by direct pulling and removal by use of a system of flat jacks. Different weak mortar types were tested in the lab to achieve the properties required to check the transfer of wind loads and the level of resistance to separation during disassembly. Using a modelled case study building, the results showed that weak lime cement-based mortars had the required properties to substitute regular cement-based mortar in joints between slabs and a stabilising wall during a critical wind load. Regarding disassembly, pulling concrete slabs out with a mobile crane would be possible if hydro demolition systems could be implemented to remove parts of the mortar joint beforehand. Using a system of flat jacks to push the slab apart showed that the method's weakness was the punching failure of the thin wall to the hollow cores. Solutions were proposed to overcome the challenge. [ABSTRACT FROM AUTHOR]

The trend toward more compact designs and congested site layouts makes it challenging for lift planners to provide feasible lift paths for mobile cranes, confronting the added risk of potential collisions when maneuvering through on-site obstacles. In some cases, particularly in congested industrial modular projects, it is inevitable for mobile cranes to walk with loads to a position with sufficient clearance to perform the lifts and place the objects in their final set position. This study contributes to the body of knowledge by introducing a comprehensive lift planning framework to plan complicated lifts involving mobile crane walking operations. Due to the lack of reliable and accurate plans for such lifts in practice and the added complexities, they are often eluded by practitioners compared with the more straightforward pick-and-set scenarios. This study proposes an algorithm for optimized planning of crane walking–involved lift operations borrowing an obstacle avoidance technique from robotics. The proposed path planner thoroughly considers site constraints and crane configurations to prevent collision between the crane body and the load with preinstalled objects. Actual case studies are presented to validate the efficiency of the proposed algorithm. The system generated the presented real-world lift in less than 5 min, satisfying the operations' optimality, safety, and feasibility. [ABSTRACT FROM AUTHOR]

Crawler cranes are the most pivotal components on large-scale modular construction sites. Generating a practical and safe lift plan significantly impacts the successful delivery of such projects. This paper introduces an integrated crane planning and lift scheduling framework for managing multiple concurrent mobile cranes' operations. The presented framework is built upon recently developed crane planning and optimization systems. It aims to balance four primary areas of project management (time, cost, quality, and safety) through schedule enhancement, cost estimation, and risk mitigation. This approach leads to a more practical lift plan. Automating the process of detecting logical issues and satisfying the constraints in the lift planning process helps to improve time efficiency and reduce errors. This paper also scrutinizes crane operations to provide a realistic budget and schedule. The developed lift planning system is flexible and practical, as validated by its successful implementation in several real modular projects in North America. • An integrated lift planning framework for multiple concurrent mobile cranes' operations in industrial construction projects. • The system automates detecting safety logical issues in the lift planning process. • This study provides a realistic budget and schedule. • The presented framework automates the creation of a 4D model report. • The system is applied and validated in a North American modular construction project. [ABSTRACT FROM AUTHOR]

In this work, the authors analyse the influence of the order and range of sequential movements of a crane's working members on the accuracy of the final cargo positioning. The analysis was conducted on the basis of a specially developed method in which the authors proposed the introduction of a geometrical indicator of positioning the load in the intermediate positions (after completing each movement sequence) and in the target position, depending on the adopted control strategy and the accuracy of kinematic input of the working mechanisms (powered mechanisms). A mathematical model was presented to enable the accuracy of unidirectional positioning of the crane's working members when conducting sequential movements controlled through the rotation of the crane column, inner and outer boom, and retractable stages of the six-section telescopic boom. Sample results of the numerical simulations showing the influence of the assumed kinematic inputs of the crane members on the accuracy of unidirectional angular and linear positioning and, consequently, on the accuracy of the final positioning of the transported cargo, were presented. Moreover, an indicator of the cargo positioning accuracy dependent on the location of an operator or a video camera and the trajectory of the cargo was developed, allowing the formulation of application conclusions. [ABSTRACT FROM AUTHOR]

This paper proposes a three degrees of freedom parallel anti-swing method by the main and auxiliary cables to address the problems related to underactuated double-pendulum anti-swing for a ship-mounted jib crane. By analysing the dynamic coupling relationship between the swing of the hook and the payload, it seeks to establish an accurate dynamic model of the anti-swing device under the ship's rolling and pitching conditions, and discusses the influence of ship excitation, the crane state, load posture and anti-swing parameters on the in-plane and out-of-plane swing angles. The analysis shows that the primary pendulum reduces the in-plane angle by 90% and the out-of-plane angle by 80%, the in-plane angle of the secondary pendulum is reduced by 90%, and the out-of-plane angle is reduced by 80%. The reliability of the simulation data is verified through experiments. [ABSTRACT FROM AUTHOR]

This paper presents a proposal for the use of energy indicators to evaluate the load modelling methods on the dynamics of a mobile crane. Three different variants of mathematical models of a load carried were examined and compared: as a lumped mass on one hook-sling, as a sphere on one hook-sling, and as a box on four hook-slings. The formalism of joint coordinates and homogeneous transformation matrices were applied to define the kinematics of the system. The equations of motion were derived using the Lagrange equations of the second kind. These equations were supplemented by the Lagrange multipliers and constraint equations formulated for the cut-joints and drives. The energy indicators were proposed to evaluate the behavior of the crane and the carried load. The authors proved that modeling a load in the form of a lumped mass is a great simplification in the analysis of crane dynamics. [ABSTRACT FROM AUTHOR]

Static load capacity of welded, high‐strength hollow section joints – presentation of the FOSTA research association HOCHFEST: projects "High‐strength hollow section joints" Truss structures made of directly welded hollow sections under predominantly static loading are used in many areas of structural steel engineering and infrastructure, such as pedestrian bridges, as well as in plant‐ or mobile crane constructions. The use of high‐strength steels can lead to economical lightweight structures with high load‐bearing capacities and wide spans. In order to use this potential of hollow section joints, normative rules are required that enable economic design. The current design rules were validated semi‐empirically by tests on joints of normal strength steels. These tests on normal‐strength hollow section joints showed that through plasticising local stress peaks are compensated and secondary bending moments are redistributed. Compared to normal strength steels, high‐strength steels have a reduced plastic redistribution capacity. This behaviour is considered in the design rules by reduction factors, which are conservatively defined because of lack of test results and have not yet been sufficiently experimentally validated for high‐strength hollow sections. The projects on "High‐strength hollow sections joints" in the FOSTA research association HOCHFEST are intended to derive differentiated and validated design rules that meet the safety requirements and enable the economical and resource‐saving use of high‐strength steels in hollow section structures. [ABSTRACT FROM AUTHOR]

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Predictive analytics have been used to improve efficiency and productivity in the construction industry by leveraging the insights from historical data with a variety of applications in project management. In the planning process of heavy industrial construction projects, mobile crane selection plays a critical role in the project's success, and poor choice of mobile crane configurations can lead to unnecessary cost-overrun and delayed schedules. In this research, the authors propose a predictive analytics framework for crane configuration selection using combined heuristic search and artificial neural network (ANN) approaches for heavy industrial construction projects. The heuristic search allows the practitioners to select the crane configurations based on engineering rules, while the ANN model utilizes the historical project data to help select crane configurations. The K-fold cross-validation is conducted to validate the designed ANN model and improve the accuracy of predictions. The results from the cross-validation test set have shown 70% accuracy. [ABSTRACT FROM AUTHOR]

Existing construction activity-monitoring technologies, such as CCTV cameras and IoT devices, have limitations, such as lack of depth information, 3D measurement errors, or wireless signal vulnerability. The limitations are particularly problematic for activities related to mobile cranes due to their high mobility and flexibility. This paper presents a 4D point cloud (4DPC) - based spatial-temporal semantic registration method to overcome the limitations. The proposed method integrates spatial-temporal semantic registration into process site 4DPC with as-designed BIM semantics. Results from a one-hour on-site experiment demonstrated that the proposed method achieved 99.93–100% F 1 accuracy in detecting BIM objects, and high resolution (centimeter-second granularity) of the trajectories of hoisting activities. This paper offers a two-fold contribution. First, spatial-temporal semantic registration represents an innovative approach to 4D point cloud (4DPC) processing. Secondly, the hoisting activities are comprehensively analyzed based on semantic registration, which can improve safety and productivity monitoring for smarter construction in the future. [Display omitted] • Registering spatial-temporal 4D point cloud (4DPC) with as-designed BIM objects for monitoring • 4DPC-based spatial-temporal semantic registration method for mobile cranes • Successful validation on one-hour 4DPC data from a night-time footbridge construction project • Satisfactory registration accuracy (F 1 = 99.95% on average) in 4DPC at object level • Intuitive and precise analysis of mobile crane-related activities based on registration results [ABSTRACT FROM AUTHOR]

Cranes are traditionally controlled by operators who are present on-site. While this operation mode is still common nowadays, a significant amount of progress has been made to move operators away from their cranes, so that they would not be exposed to hazardous situations that may occur in their workplace. Despite its apparent benefits, remote operation has a major challenge that does not exist in on-site operation, i.e., the amount of information that operators could receive remotely is more limited than what they could receive by being on-site. Since operators and their cranes are located separately, human–machine interface plays an important role in facilitating information exchange between operators and their machines. This article examines various kinds of human–machine interfaces for remote crane operation that have been proposed within the scientific community, discusses their possible benefits, and highlights opportunities for future research. [ABSTRACT FROM AUTHOR]

Trough bridge over the river Broye – a pedestrian and cycling bridge made of weathering steel with laser‐cut webs The pedestrian and cycling bridge over the river Broye (Switzerland) connects the new residential area Rives de la Broye to the nearby town Payerne. The superstructure of the 36 m span trough bridge is made of 26 t of weathering steel. Due to the trough cross‐section, the full superstructure is above flood level. Webs and upper flanges do not only have structural purpose but also function as railings and handrails. The webs have a perforated pattern, which was generated computer‐aided and CNC‐laser cut. The pattern was chosen according to the stress distribution in the webs. The remaining material follows the stress trajectories and the seizes of the perforations depend on the local stresses. The pattern does not only make the superstructure look more transparent and lighter, but also reduces the total weight and saves material. The bridge superstructure was completely prefabricated and installed within hours using a mobile crane. At the abutments a restraining effect is achieved by a combination of a tension and a compression bearing, which positively affect the maximum deflection in mid‐span and the dynamic bahaviour. The bearings can move at bearing level to allow for temperature differences. [ABSTRACT FROM AUTHOR]

Accurate selection and location of mobile cranes is a critical issue on construction sites, being able to contribute to the improvement of the safety and efficiency of lifting operations. Considering the complexities and dynamics of construction sites, this study aimed to develop a useful approach for automated selection and localization of mobile cranes based on the simulation of crane operations. First, the information required for crane selection and localization is analyzed and extracted from BIM (building information modeling). Then, mainly considering the crane capacity, the initial crane type is selected with candidate location points. Based on the simulation of lifting operation at the candidate points, feasible location points and crane types are determined through three constraint checks (i.e., environment constraint, operation constraint, and safety constraint). Besides, two kinds of efficiency optimization, namely lifting time minimization and crane movement minimization, are presented to figure out the best location points from the feasible points. Finally, the proposed approach is validated using a case study. This research contributes to not only crane operation planning but also automatic construction simulation, thus supporting the implementation of intelligent construction in the future. [ABSTRACT FROM AUTHOR]

Purpose. Analyzing the stress distribution in the metal structure of the gantry crane under the cyclic operation mode and identifying stress concentrators in the crane column to assess the survivability of the machine. Methodology. In order to achieve the objective, the methods employed included analytical calculation method, finite element method, as well as differential and integral calculus methods. To study the state of the metal structure of the gantry crane, namely the column, the program Solid Works and its application Simulation were used. Findings. Using the CAD/CAE-system, the loaded condition of the metal structure of the gantry crane was modeled and the maximum working loads were determined, and a calculated scheme of their operation was constructed. The method is presented for calculation of survivability of load-bearing elements of the crane taking into account coefficients of intensity and concentration of stresses which allow defining speed of growth of cracks in dangerous stress zones of a metal structure. Originality. The existing methods for designing crane metal structures gained their traction. The integrated technique for assessing crane reliability has been suggested for the first time. This technique is focused on estimating the survivability of components elements. For the first time solid-state models of the crane and its column have been developed; the analysis of the stress-strain state of the column was performed, maximum stresses were determined, stress concentration points in the metal structure of the column were identified and recommendations for improvement of stress zones were presented. Practical value. The presented method for assessing the reliability of metal structures of gantry cranes can be implemented in the practice of design organizations for the development, design of new gantry cranes and modernization of existing ones. The obtained results provide an opportunity to assess the accumulated damage in the elements of the metal structure, to predict the development of defects to a critical size, as well as to decide on the further operability of a gantry crane. [ABSTRACT FROM AUTHOR]

The characterization of toughness properties in standard Charpy or fracture mechanics tests calls for thickness requirements to be met. Therefore, the characterization of toughness properties is a problem for thin‐walled structures. Replacing Charpy impact toughness testing by impact notch tensile testing can solve this problem. However, the toughness requirements are still expressed in terms of standard test results. Therefore, a framework is proposed here for translating these standard test requirements into impact notch tensile test requirements. The proposed framework relies on numerical simulations with a phenomenological damage mechanics model, which uses state‐of‐stress‐dependent, strain‐based criteria for the prediction of local damage and global fracture. This model takes the effects of non‐proportional strain paths into account and applies different criteria for cleavage and ductile fracture in order to predict correctly the activation of cleavage and ductile fracture mechanisms in the corresponding numerical simulations. [ABSTRACT FROM AUTHOR]

In the present work, a new method for the determination of the outrigger loads in mobile cranes is proposed. The approach adopted assumes the mobile crane as a rigid body and the ground having a linear elastic behavior. The outrigger reactions are determined, using the concept of complete support pattern, through the calculation of the area of triangles constructed within it. The main feature of the method is that the determination of the outrigger reactions can be done by means of graphical considerations with the advantage to perform the task quickly and without the use of complicated calculations. The knowledge of the outrigger pattern, the resultant of all the forces applied and the center of mass of the system crane-payload are only needed as input data. Although the method is suitable for cranes with an outrigger system of any number and shape, the simplification deriving from the use of the graphical approach is fully available only for an outrigger system with four outriggers having a specific shape. These configurations, however, represent the most common configuration found in real applications. The validity of the method proposed has been proven comparing the results with data available in the cranes' manuals and with actual reactions of the outriggers of a mobile cranes operating on site. [ABSTRACT FROM AUTHOR]

Brittle fracture resistance of high‐strength steels in mobile crane engineering The definition of toughness requirements for load‐bearing steel structures for mobile cranes are largely based on empirical values or their derivation is not transparent and understandable. For the first time, fracture mechanical methods enabled the assessment of requirements for material toughness for brittle fracture‐proof operation in a differentiated manner and quantified in a comprehensible manner. The methodology presented, allows the expected service life and the required material toughness to be estimated for various components, load conditions and specifications for weld seam irregularities. [ABSTRACT FROM AUTHOR]

Mobile cranes account for a considerable proportion of crane-related accidents in South Korea. The authors used descriptive and non-parametric statistics to analyse 245 fatal accidents in South Korea from 2007 to 2016. The results showed that human error and crane problems were the main cause of accidents; riggers accounted for the largest number of deaths. To reduce the number of mobile crane fatalities, the authors made recommendations in four areas: educational aspects, mobile crane aspects, technical aspects and other issues. Firstly, business owners need to establish a systematic education system suitable for workers in mobile crane operations. Secondly, efforts should be made to tighten the quality of safety inspections of cranes and supervision of workplaces. Thirdly, efforts should be made to develop more human error-free equipment. Lastly, it is necessary to develop a systematic accident reporting system containing more detailed information to allow a fuller understanding of accident causation. [ABSTRACT FROM AUTHOR]

Reliability engineering is needed for scheduling maintenance to improve system or equipment performance. The purpose of this paper is to provide recommendations for maintenance schedules based on reliability, availability, and maintainability (RAM) analysis that optimizes the availability of mobile cranes operating in Indonesian oil and gas companies. This paper begins with searching for a critical system using the Pareto principle. The critical system is then made a reliability block diagram to facilitate the analysis. However, before conducting the analysis, it is necessary to know the characteristics of the probability distribution of the data so that the analysis results are accurate and stable. Analysis of reliability, availability, and maintainability (RAM) is then carried out in the probability distribution equation for each system. The analysis results show that the implementation of maintenance at the time of reliability reaches the mean time between failure, and the maximum maintainability time is 240 minutes. The result is an increase in the availability of the lower structure (LS) system by 0.53% (98.78% to 99.31%), electrical and safety equipment (ESE) by 0.19% (99.02% to 99.21%), upper structure (US) was 0.07% (99.32% to 99.39), and overall system availability was 0.07% (99.31% to 99.38%). [ABSTRACT FROM AUTHOR]

The dynamic loading of hydraulic cylinders that adjust the boom radius of a crane is numerically modeled, in the following conditions: prolonged load ascent, sharp load ascent, sudden load removal from jib, outrigger sagging, change in boom radius (jib lowering). In each case, the displacement of the jib head and the hinge attaching the hydraulic jacks and also the reaction of jack components are plotted. The stress amplitudes for the cylinder rod and piston are calculated, taking the stiffness of the working fluid into account. [ABSTRACT FROM AUTHOR]

Cranes are one of the most critical and expensive pieces of construction industry equipment requiring intense safety considerations. Lifting crews should attempt to develop an effective lift plan to improve the operation's safety and reduce the risks of potential accidents. Although various systems are developed to enhance lifting operations' safety, most cannot evaluate the entire lifting process in an interactive visual environment. This paper contributes to the body of knowledge by presenting a crane simulator system developed in the virtual reality (VR) environment integrated with a database of comprehensive lift studies and a detailed crane path planning system. This interactive system evaluates the lift operation quantitatively in real time in terms of its safety and practicability for the entire operation (entire lift path). The developed system can be employed in practice by crane operators and lift engineers for various objectives, including gaining hands-on experience before the actual operation, enhancing engineered lift planning, increasing workplace awareness, and evaluating and mitigating lift-related risks. The proposed framework is validated through two scenarios in a modular construction project in Alberta, Canada. [ABSTRACT FROM AUTHOR]

Planning lift activities of mobile cranes for a modular project can raise productivity and improve safety. An optimized lift plan is essential for multiple lifts due to high rental cost of heavy lift cranes. However, choosing among a large number of available lift options (e.g., types, configurations, and locations of cranes) to develop multilift plans can be challenging. Despite numerous efforts in this area, there is still room for improvement to enhance the optimality of solutions, which leads to considerable cost reduction. This paper introduces an integrated framework to automatically generate an optimum lift plan based on a predetermined lifting sequence. Dijkstra's search algorithm is utilized in the current study to select each module's optimum lift option. This study contributes to the body of knowledge by proposing an enhanced graph-based optimization algorithm for multiple concurrent heavy lift operations. The suggested framework is validated successfully in an actual modular construction project in Alberta, Canada. The results are also compared with the previously developed lift planning algorithms, showing a remarkable reduction in the project's total cost. [ABSTRACT FROM AUTHOR]

While up-right build structures are under construction, an over-hung crane has a major role in efficient lifting and transporting heavy materials from one point to another. There are several types of cranes for a variety of construction sites, such as bridge/overhead, barge lift, tower crane, etc. The mobile crane is one of the most widely used types of construction equipment due to its mobility. Unfortunately, the number of crane accidents including casualties and deaths has increased over the last decade. In order to reduce these fatal tragedies, a dynamic simulator of mobile cranes based on analyzed overturn limit data has been developed and analysis results have been applied to site tests. The test bench is formulated to simulate the actual construction field and some practical experiments have been performed in realistic manners of operation. Moreover, wireless network communication systems are applied for monitoring the status of the crane from a distance where visibility is not secure. Consequently, the applicability in the field derived from operating the simulator and actual vehicle testing confirmed the feasibility of applying it to construction sites. [ABSTRACT FROM AUTHOR]

Modular construction methods are adopted in many spatial and temporal limited projects. As the major equipment used in modular construction, the mobile crane affects the safety and efficiency of construction significantly. Currently, building information modeling (BIM) is widely adopted to improve the lifting operation planning of cranes. However, the inaccurate simulation of the dynamic construction environment makes those BIM-based lifting operation planning methods unsuitable for land mobile cranes operation planning, such as in the overpass bridge construction project, which may cause several safety risks during the lifting process. Based on an overpass steel bridge construction project, this paper attempted to integrate the BIM and unmanned aerial vehicles (UAVs) to streamline lifting operation planning and construction monitoring. Specifically, in the preliminary stage, a level of development (LOD) 400 steel superstructure model was built and then divided into eighty sections. In addition, a three-dimensional (3D) geology model of the as-is construction site was modeled by UAV-captured images. Then, a fusion model which contains the lifting modules models, the as-is site model, and the crane model was gathered, based on which the collision detection was conducted by 4D crane operating path simulation. According to the results, three potential collisions were found and eliminated by lengthening the jib of the crane from 43.5 m to 46.5 m. Furthermore, the optimum crane location for lifting each steel structure was determined based on the 3D geology model. The study shows that the UAV is able to acquire geological information and then 3D simulates the real construction environment quickly and accurately. Furthermore, BIM and UAV have the potential to optimize the design and construction as well as the monitoring of bridge projects. [ABSTRACT FROM AUTHOR]

Mobile cranes have been used extensively as essential equipment at construction sites. The productivity improvement of the mobile crane affects the overall productivity of the construction project. Hence, various studies have been conducted regarding mobile crane operation planning. However, studies on solving RCP (the repositioning mobile crane problem) are insufficient. This article presents a mobile crane reposition route planning optimization method (RPOS) that minimizes the total operating time of mobile crane. It converts the construction site into a mathematical model, determines feasible locations of the mobile crane, and identifies near-global optimal solution (s) (i.e., the placement point sequences of mobile crane) by implementing genetic algorithm and dijkstra's algorithm. The study is of value to practitioners because RPOS provides an easy-to-use computerized tool that reduces the lengthy computations relative to data processing and Genetic Algorithms (GAs). Test cases verify the validity of the computational method. [ABSTRACT FROM AUTHOR]

Improper planning and management of heavy lifts is a major cause of cost overruns, delays, and, more importantly, safety incidents in industrial megaprojects. Automated lift planning is widely acknowledged as an effective solution. This research presents an automated lift path planning system for mobile cranes leveraging space discretization and an obstacle-avoidance technique from robotics. The proposed method treats the lifted object as a three-degree-of-freedom convex traveling through the surrounding environment [a given two-dimensional (2D) elevation] with discretized rotational and translational motions in polar coordinates. It efficiently finds the best feasible pick location and optimized collision-free lift path in the polar coordinate system to the set location. This system is a state-of-the art advancement in crane path planning because it mimics the crane's intrinsic behavior and generates paths considering cost functions for safety, practicality, and economic objectives to enable its implementation in real practice settings. Illustrative examples are presented to verify the proposed approach and demonstrate its superiority over past similar path planning systems in terms of optimality and operational ease. [ABSTRACT FROM AUTHOR]

The "Pont Bleu" replacement and refurbishment project consists of the reconstruction of an existing road viaduct, with a traffic load of 20,000 vehicles/day and spanning two roads and eight railway lines (600 trains/day), with minimum traffic disruption. The new viaduct has a length of 176 m and its width varies from 14.2 to 15.6 m. The main span over the railway lines is 56 m long. Preliminary works lasted 12 months while maintaining road and rail traffic. Replacement of the entire superstructure was realised over a period of 45 days with complete road traffic interruption and six punctual rail traffic interruptions, employing a mobile crawler crane of 26,930 t/m capacity, which performed 26 lifting operations during this period of time. [ABSTRACT FROM AUTHOR]

The presented strength and fatigue calculations refer to an unsupported deck crane and its three distinct parts: housing, jib and column. Static loads applied to the structure were due to the crane's own weight and a maximum working load, corresponding to a maximum lifting capacity at a maximum outreach of the crane. The numerical analysis was aimed at determining the thickness of the skin plating of the column and the number, shape and distribution of stiffeners in the column, housing and jib, ensuring that the crane yields correct strength and fatigue parameters. During the process of designing marine structures, the standard numerical analysis is, in many cases, limited to calculations in the basic strength range. Even when using numerical methods of analysis, complex strength and fatigue calculations are often not performed. The modern numerical analysis chain for marine structures should concentrate not only on strength analysis, but should take a further step, which encompasses fatigue analysis. The article presents a new outlook on design methods, which should be the entry point to the design of marine structures. Based on the acquired number of cycles of fatigue life, it is possible to estimate, with a sufficient degree of accuracy, the practical service life of a structure. To solve the problem, the authors used the finite element analysis software ABAQUS supported by the fe-safe system. [ABSTRACT FROM AUTHOR]

The modular construction approach relies heavily on mobile cranes. With the increase in weight of modules, the ground bearing pressure (GBP) applied by the hydraulic crane also increases. To avoid ground failure, the primary technique is to determine the GBP by calculating the resulting force at each outrigger and assuming it is distributed uniformly over the surface area of the mat under the outrigger. Finite element analysis (FEA) indicates that the pressure profile beneath the crane mat is not uniform in nature, which means the traditional method of calculating the GBP is inaccurate. In this study, a new method is proposed to determine the GBP profile. The proposed methodology can determine the GBP at 16 points, the four corners of each of the four outriggers. For a theoretical case study, a hydraulic crane Grove GMK 7550 with three different payloads is examined and the results are verified by using FEA. [ABSTRACT FROM AUTHOR]

Purpose: Heavy industrial construction often relies on large mobile cranes to erect equipment and pre-assembled modules. Engineering calculations are required for the lifting analysis where lifting capacity is analyzed to ensure the feasibility of the lifting scenarios. Such engineering calculations are often presented in static formats, e.g. two-dimensional or three-dimensional models. However, it is difficult to help practitioners (e.g. lifting engineers, site crews and operators) understand the complexity of the lifting process and thus operational decisions are often made intuitively. Therefore, this paper aims to introduce a game-based simulation system to allow for interactive analysis of the lifting process to improve lifting efficiency and safety. Design/methodology/approach: The proposed method treats the mobile crane as a robot with degree-of-freedoms, and the movements are simulated in the Unity game environment. The lifting capacity is calculated dynamically based on the lifting object weight, rigging weight and lifting radius. Findings: Compared with the four-dimensional visualization, this development has added a dimension of real-time interactive simulation; this allows the users to understand the complexity and feasibility of the lifting process. Originality/value: The developed prototype has been tested and validated using a real case study from a heavy industrial project with the possibility of generalizing crane lifting configurations. [ABSTRACT FROM AUTHOR]