沉管隧道接头力学模型及刚度解析表达式

接头刚度是表征沉管隧道接头性能的最重要参数. 目前沉管隧道接头刚度的取值既无现成的解析表达式或图表可循, 也无接头力学性能试验数据支持. 该文根据接头构造设计特点提出力学假定, 将接头GINA止水带抽象为弹簧, 接头板则假定为不产生挠曲变形的刚性板, 在此基础上建立了接头的力学模型. 根据受力平衡方程和变形协调方程, 推导出接头刚度的解析表达式. 通过与所设定的接头三维精细化基准模型在相同设计参数下的结果对比, 验证了接头力学模型及刚度解析解的合理性. 最后应用该力学模型进行了接头参数敏感性分析, 预测了各种因素对接头刚度的影响规律.

MECHANICAL MODEL AND ANALYTICAL SOLUTION FOR STIFFNESS IN THE JOINTS OF AN IMMERSED-TUBE TUNNEL

Stiffness is one of the most important parameters in representing the performance of joints of an immersed tunnel. At present, neither analytical solutions nor experimental data are available to study joint stiffness in immersed tunnels. A mechanical model for element joints is proposed with assumptions based on the design characteristics of immersed joints, in which springs are assumed to model behaviors of GINA rubber and non-deformable rigid plates are assumed for segments. An analytical solution for joint stiffness is derived according to equations of stress equilibrium and deformation compatibility. A benchmark model, a three-dimensional refined model of an immersed joint, is used to calibrate the presented model and the derived closed-form solution for joint stiffness. Comparison under the same geometrical and material parameters shows a high degree of consistency between the two, which verifies both the presented model and analytical solution. Finally sensitivity analyses of parameters for joints are carried out using the proposed model, and potential influences of parameters on joint stiffness are predicted.