基于流固耦合作用的海底隧道初期支护安全影响因素分析

以青岛海底隧道试验段为工程背景,基于流固耦合理论对海底隧道初期支护安全性的影响因素进行分析,结论表明:(1)注浆加固显著改善了洞周土体强度和整体性,塑性区范围得到有效控制;(2)注浆加固优化了支护结构的受力,随着加固圈厚度的增加,洞周位移出现不同程度的衰减,加固圈厚度对减小水压的贡献依次为:拱顶拱腰拱脚仰拱;(3)随着加固圈渗透系数的增大,洞周水压力随之增大;(4)在流固耦合作用下,仰拱处的土压力远大于其他部位;(5)现行支护参数条件下,海底隧道初期支护结构满足安全性要求,现场实测与数值计算基本相符。

Analysis on Impact Factors on Initial Support Safety in Subsea Tunnel Base on Couple Fluid-mechanical

With reference to Jiaozhouwan subsea tunnel in Qingdao and based on the coupled fluid-solid theory,the impact factors are studied on initial support safety in subsea tunnel. The results show that:( 1) The strength and integrity of surrounding rock are improved significantly by grouting reinforcement and the plastic zone is effectively controlled;( 2) The force of the supporting structure is optimized by grouting reinforcement ring,with the increase of the reinforcement thickness,the displacement attenuates in a certain degree,and the thickness of the reinforced ring contributes to the reduction of water pressure in such a sequence: arch top to arch web to arch foot to inverted arch;( 3) With the increase of the permeability coefficient of reinforced ring,the water pressure around the tunnel is increasing;( 4) The earth pressure at the inverted arch is much bigger than anywhere else under couple fluid-mechanical;( 5) The initial support structure meets the requirement for safety with the current support parameters,and the site measurements agree basically with the numerical calculations.