悬浮隧道运营期横断面分析方法及受力特征研究

Analysis method and stress characteristics of cross-section of submerged floating tunnel in operation stage

借鉴港珠澳大桥岛隧工程沉管隧道横断面结构分析方法,依托工程研究,进行运营阶段横断面分析方法及受力特征研究。得到如下结论:1)首次提出了悬浮隧道典型横断面平面应变模型边界约束方式,内力计算结果相对保守;2)横断面外轮廓曲线越光滑、棱角越小,横断面受力性能越好;3)系统划分与整理各种永久荷载、可变荷载及偶然荷载,初步研究了ULS和ALS系数取值及荷载组合;4)20 m淹没水深净浮力作用内力包络值约为温度梯度作用的3倍,交通荷载作用的10倍;5)ULS轴力及剪力包络值大于ALS,而弯矩包络值前者小于后者。

Based on HZMB Island-Tunnel Project immersed tunnel cross-section analysis method as part of the engineering study,we carried out a study on cross-section structural analysis method and internal force characteristics of submerged floating tunnel(SFT).Findings are:1)the boundary constraint method of plain-strain model of the SFT tube typical sections is put forward for the first time,and the results of internal force calculation are relatively conservative;2)the smoother the outer contour curve and the smaller the edge angle of the cross section,the better the mechanical performance of the cross section;3)various type of permanent loads,variable and accidental loads are systematically divided and sorted out,and the ULS and ALS coefficients and load combinations are preliminarily studied;4)the member force resulted from residual buoyancy acting on cross-section structure of 20 m water burial depth is approximately equal to 3 times of that of temperature gradient and 10 times of that of traffic load;5)the ULS's axial force and shear force envelope is larger than that of ALS's,and the opposite applies to bending moment.