为获得海底隧道钢拱架锈蚀后二次衬砌荷载分担比演化规律，进而保障隧道长期安全性，依托某海底隧道建立考虑钢拱架锈蚀作用的初期支护-二次衬砌的三维实体荷载-结构模型，分析不同锈蚀程度下初期支护-二次衬砌间接触应力、二次衬砌安全性及荷载分担比变化规律。研究结果表明： 1）随着钢拱架锈蚀率由0%增加至60%，初期支护与二次衬砌的接触应力明显增加，拱顶、拱肩、边墙、拱脚、仰拱接触应力增幅分别为46%、45.11%、49%、47.42%、44%，相应二次衬砌安全系数呈下降趋势； 2）钢拱架锈蚀率从0%至60%，二次衬砌荷载分担比由0.54增加至0.63，增幅达16.67%； 3）综合考虑钢拱架锈蚀率、二次衬砌厚度、二次衬砌弹性模量3个因素，建立二次衬砌荷载分担比预测公式。
The evolution mechanism of load-sharing
ratio of secondary lining under steel
arch frame corrosion of subsea tunnels is crucial for long-term safety of the tunnels. Herein, a three-dimensional
solid load-structure model of the primary support-secondary lining under corrosion effect of the steel arch frame is
established based on a subsea tunnel. The variation patters of the contact
stress between the primary support and secondary lining, the safety of the
secondary lining, and the load-sharing ratio under
different corrosion degrees of steel arch frame are examined. The results
indicate the following: (1) The contact stress between the primary support and
secondary lining sharply increases as the corrosion rate of steel arch frame
increases from 0% to 60%; the contact stress at the crown, arch shoulder,
sidewall, arch foot, and invert increases by 46%, 45.11%, 49%, 47.42%, and 44%,
respectively. The corresponding safety factor of the secondary lining shows a
downward trend. (2) The load-sharing ratio of the
secondary lining increases from 0.54 to 0.63, with an increase of 16.67%, as the corrosion rate of the steel
arch frame increases from 0% to 60%. (3) A prediction formula for the load-sharing ratio of the secondary lining is established by
comprehensively considering the corrosion rate of the steel arch frame, the
thickness of the secondary lining, and the elastic modulus of the secondary
lining.
