沉管隧道纵向静力计算问题探讨

Discussion on Longitudinal Static Calculation of Immersed Tunnel

为进一步综合分析长距离沉管隧道纵向内力和变形,保障其接头水密性,讨论了沉管隧道结构纵向静力分析计算模型和应考虑的一些问题,包括接头受力机制、GINA止水带选型和水密性检算,以及纵向沉降差与纵向弯矩和剪力的关系等。总结了简单而高效的弹性地基梁纵向计算模型及其接头模拟方法;提出使用地层-结构模式和强制位移法的三维壳体模型作进一步的补充细化分析;指出隧道纵向沉降曲线的曲率及曲率变化率分别影响着结构的纵向弯矩和剪力;给出接头的止水带选型及水密性验算工作如何与隧道结构纵向计算相互结合。

In order to further comprehensively calculate the longitudinal internal force and deformation of long immersed tunnel,and to ensure the joints＇ watertightness,the calculation models for longitudinal static analysis of immersed tunnel and some problems,i. e. the joint mechanics,selection of GINA gasket with its and watertightness verification and relationship among longitudinal settlement difference,longitudinal bending moment and shear force,etc.,are discussed.And then the simple and efficient elastic foundation beam calculation model and joint simulation methods are summarized; the 3 D shell models with stratum-structure mode and forced displacement method are put forward for supplementary detailed analysis. Finally,it is pointed out that the curvature and curvature variation rate of the longitudinal settlement curve of the tunnel affect respectively the longitudinal bending moment and shear force of the structure; and it is given that how the selection work and watertightness verification of water seal cooperate with longitudinal calculation of tunnel structure.