| With the development of large-scale transport ships,port construction is gradually moving towards offshore and deep water area.As a new type of pile supported wharf structure suitable for offshore and deep water area,all-vertical-piled wharf structure has broad application prospects for its characteristics,including reasonable bearing force,small water blocking area,low construction cost and fast construction speed.The dynamic response of the structure are quite outstanding,due to the long piles and great structural flexibility.As one of the most important dynamic loads in wharf design,seismic action has great destructive effect on the structure.Therefore,it is of great significance to carry out the research on seismic optimization design of all-verticalpiled wharf.First of all,the finite element model in this paper based on an all-vertical-piled wharf with concrete slabs and beams is established by ANSYS parametric design language,and the model’s natural vibration characteristics and dynamic response under horizontal earthquake are obtained through modal analysis and response spectrum analysis respectively,thus laying the foundation for structural optimization.And then a mathematical model for seismic optimization design is preliminarily established.It takes the sectional dimension of each component,pile spacing and lateral bent spacing as design variables,takes the displacement and stress response under earthquake as constraint variables,and takes the volume of materials required for each unit area as objective function.Afterwards,the sensitivity analysis of objective function and constraint variables in the mathematical model of optimization is carried out,and the mathematical model is adjusted appropriately based on the analysis results.Then,the calculation of optimization is in progress by combining random design generation tool and subproblem approximation method.The results show that the design variables are reduced by about 17% on average,and the objective function is reduced by 46.9% compared with the original structure under the condition that the optimized structure meets aseismatic design requirements.Finally,the new structural type of the wharf is further optimized based on the optimization model.By comparing the free vibration characteristics and spectral analysis results before and after optimization,the conclusion that the all-vertical-piled wharf with bottom beams has higher overall stiffness and better seismic performance is drawn.At the same time,the influence of the change of the bottom beams position on the seismic performance is discussed.That is,lowering the position of the bottom beam within a certain range can effectively reduce the lateral deformation of the structure under the horizontal earthquake.In general,the seismic optimization design method adopted in this paper has clear process and good effect,which has certain reference significance for aseismatic design of similar wharf structures. |
