The most appropriate definition of the crane can be considered as “ A crane is a self-contained piece of equipment, which lift and lower loads by means of ropes and pulleys and move the loads horizontally” by Shapiro (1999). Building materials like steel frames, temporary formwork, concrete, precast components and other objects such as building equipment need to be lifted and moved horizontally to the installation positions or work platforms. This lifted work relies heavily on the crane – the key piece of equipment on site. It is estimated that 35-45% of the cost of building work is spent on materials, (Harris, 1989), costs of materials handling range from 30 to 80 per cent of total construction cost (i.e. building cost). Hence material…show more content… Model optimizes the hoisting time, balancing of workloads, appropriate task assignment and minimize the crane interference. First, the initial location model classifies tasks into groups and identifies feasible location for each crane according to geometric ‘‘closeness.’’ Second, the former task groups are adjusted to yield smooth workloads and minimal conflicts. Finally, a single-tower-crane optimization model is applied crane by crane to search for optimal location in terms of minimal hook transportation time. Model proposed will behave well certainly for cast in-situ construction.
A graphical interface for crane selection and location is determined by the Farrell and Hover (1989). Their objective is to prevent crane accidents due to improper planning and site optimization in high rise building construction. On the basis of trial and error and with the aids of computer graphics, position for the multiple crane is chosen, concerning crane safety by ensuring adequate crane capacity, and placement of crane with due considerations of overhead power line and other hazardous area such as steep inclines, soft soil, rights of way, and office…show more content… Therefore, the tower crane and its supply point locations become the key factors of the temporary site facilities layout for high-rise construction projects. Optimisation of the tower crane(s) locations and its supply point(s) then is the most important part of facilities layout planning. In practice, tower crane position(s) are usually determined through trial and error method, considering site topological layout and overall coverage of tasks as well as the surrounding environment (Zhang et al., 1999). These factors vary from one project to another, thus resulting in different site layout strategies and approaches. This fact makes the CLP, which is recognized as nonlinear and discrete optimisation problem, difficult to solve by scientific