Finite Element Analysis of the Radial Gate with Different Arrangements of the Gate Arm

One of the important criteria to consider in a design of radial gate is the gate weight. The gate weight directly affects the capacity of the hoisting equipment as well as the total construction cost of the radial gate system. The heavier the gate, the higher the capacity and the cost of the hoisting equipment as well as the total construction cost of the gate. This study sets out to investigate the structural behavior of main horizontal girder of radial gate at different gate arms arrangements. It is to identify the most appropriate gate arms arrangement as well as the optimum ratio, R length of overhang to main horizontal girder length. By selecting appropriate location of the gate arms connecting horizontal girder, the gate weight can be reduced. This is due to that the selection of appropriate location is very significant in reducing stresses in the main horizontal girder. The lower the stresses, the smaller the size of the girder can be used which results in the reduction in the gate weight. The investigation starts with modelling the gate structural members and continues with the development of an appropriate finite element model for the analysis of gate arms arrangements with different ratios length of overhang to the horizontal girder length. From the analysis, the inclined gate arms arrangement with the ratio, R of 0.2 is the optimum arrangement of the gate arms which produces the lowest maximum stress at the mid-span of horizontal girder. On the contrary, the highest maximum stress at the mid-span occurs in the model with the parallel gate arms arrangement. It shows that the use of inclined gate arms arrangement can reduce the maximum stress at the mid-span with the maximum percentage of stress reduction is 91.94%. However, by looking to the stresses induced in the whole body of the horizontal girder, the gate arms arranged in parallel to the pier face yields the lowest maximum stress in the girder compared to the inclined gate arms arrangements with the percentage difference between the lowest and the highest maximum stresses is 14.87%. The range of percentage difference of maximum stress among the model with ratios, R as considered in the analysis and the model with parallel gate arms arrangement is between 0.99 % to 14.87%.