Importance evaluation and weak link analysis for members of overhead vertical wharfs located at inland rivers

As all-vertical-piled frame wharfs not only have large capacity but also are able to adapt to the conditions of large water level difference. Such wharfs are widely used in construction of ports located at southwest mountain rivers. However, this kind of structure has so many members and the force condition is so complicated that it is hard to determine the force transmission route and weak links of the members. A method for evaluating importance, which is based on generalized stiffness, is applied in calculating importance factors of wharf members, under the situation of only ship load and combined load, separately, and analyzing force transmission route and weak links. The analysis results indicate that piles are more important than beams. Generally, the upper members of the piles are less important than the lower members, and the importance of beams is related to the impact location of ships. According to importance factors, there are five weak links in the inland river wharfs: the front piles, piles located in back row, the front beam of the top layer, and the rear and front nodes of the bottom bent frame. So, enough safety stock for the above weak links should be reserved in design. The force transmission route of the frame wharf is mainly constituted by the outmost members. The research results will provide a reference basis for structure optimization of the frame wharfs.