为了探讨管节接头在地震作用下的减震措施和手段,首创性地提出了基于金属屈服耗能阻尼器的沉管隧道管节减震耗能方法,设计了一套可用于沉管隧道管节接头的减震耗能装置,并通过关键参数优化的方法,以接头弯矩-转角曲线所围成的面积作为优化目标函数,对该减震耗能装置的线刚度进行优选;最后,通过对接头施加水平弯矩荷载,完成了无减震耗能装置接头和安装减震耗能装置接头2组大比尺对比结构试验,分别得到2组试验工况下管节接头的弯矩-转角曲线,计算得到管节接头力学性能参数(如抗弯刚度和滞回圈面积等),并对各参数进行了对比分析,检验了该减震耗能装置用于提高沉管隧道抗震性能的技术可行性。试验结果表明:无减震装置和安装减震装置后,接头的弯矩-转角曲线均出现明显的滞回圈,两者滞回圈形状大致相同;与无减震耗能装置的接头试验相比,安装该减震耗能装置后,在接头承受相同的转角条件下,接头所承受的最大弯矩从730kN·m提高到了1 000kN·m,提高了约37%;接头弯曲刚度由6.19×105kN·m·rad-1提高到8.97×105 kN·m·rad-1,增大了约45%;而反映接头耗能性能的接头弯矩-转角曲线所围成的滞回圈的面积提高了约69%,接头的滞回性能得到了显著的提高。
In order to investigate the earthquake reduction performance of immersion joint subjected to seismic loading,based on metal buckling dampers,a novel method for enhancing the seismic performance of the immersion joint was proposed.An energy-dissipated equipment for the tube joint in immersed tube tunnel was designed.By the method of optimizing key parameters,taking the area encircled in moment-rotation curve as the optimal objective function,the elastic stiffness of the proposed energy dissipation equipment was selected.Finally,two large-scalestructural comparison experiments for joints with and without energy-dissipated equipment were conducted by applying horizontal bending moment to the joints.The moment-rotation curves were obtained as well as the mechanical parameters(e.g.flexural stiffness and area of hysteretic loop)of the joint under the two test cases.These parameters were compared and analyzed and technical feasibility of the equipment for enhancing the seismic performance of the tunnel was verified.The results show that the hysteretic loops with similar shape are found obviously in both moment-rotation curves for joints with and without energy-dissipated equipment.Compared to that without such equipment,the maximum bending moment of joint with the equipment increases from 730 to 1 000kN·m,around 37%;the flexural stiffness of the joint increases from6.19×105 to 8.97×105 kN·m·rad-1,around 45% under same rotation;the hysteretic area of the immersion joint encircled by the moment-rotation curves which fully reflect the energy dissipation of joint increases about 69%.These results show that the hysteretic performance of the joint is remarkably enhanced.