本文采用数值模拟的方法,研究向家坝升船机结构的动力特性、结构的位移与加速度反应、墙体应力与联系梁内力反应,并分析了纵导向机构的刚度、纵向阻尼装置的阻尼系数对船厢与塔柱之间地震耦合力的影响。研究结果表明,船厢内水体的基频远离塔柱结构的基频,水体对塔柱结构的动力影响不大;塔柱结构墙体应力不大,但是,顶部联系梁特别是结构缝外侧的主横梁、主纵梁的根部附近区域内力较大。基于大量的计算成果,建议向家坝升船机每套纵导向装置的刚度在540~660MN/m之间选取,并建议设置适当的纵向阻尼装置(阻尼比为5%~10%)以降低纵导向耦合力。研究表明,若设置相当于5%阻尼比的纵向线性阻尼器时,每套纵导向装置的耦合力可降低至3.8~5.3MN。
Numerical simulation method is adopted in this paper to study the dynamic behaviors,displacement and acceleration responses,wall stress and beams' inner forces of the shiplift structure of Xiangjiaba hydro project.Influence of rigidity and damping of the longitudinal guiding systems on their coupling forces is also analyzed.The results are as follows.The water inside the ship has little influence on the dynamic response of tower structure,since the first-mode frequency of the water is far away from the tower's.The stress in the wall is not very large,but the inner forces of the link beams at the top of tower are significant,particularly at the butts of the main transverse and longitudinal beams outside the structure joints.It is suggested that the rigidity of each longitudinal guiding system of this shiplift be in the range of 540~660 MN/m and that the damping ratio of longitudinal dashpots in the range of 5%~10% to control longitudinal coupling forces.If the design is comparable to longitudinal linear dashpots of damping ratio 5%,then each longitudinal coupling force would be as low as 3.8~5.3 MN.