为探究大直径盾构隧道双道防水密封垫的合理分布方式，采用考虑接缝细部构造及混凝土塑性损伤的精细化数值模拟方法，通过纵缝抗弯足尺试验验证该方法的有效性，并进一步利用精细化数值模拟对比分析密封垫双道内外分布及密封垫双道外侧分布下接缝的力学性能及防水性能。研究结果表明： 1）精细化数值模拟在反映接缝抗弯性能方面具有良好的可靠性； 2）接缝受压区高度、张开量及螺栓应力随弯矩增大呈现4阶段的发展模式，受压侧外缘接触一定程度提升了抗弯性能； 3）轴力显著影响接缝初始抗弯刚度的保持，且轴力与初始抗弯刚度并非完全正相关，高轴力下初始抗弯刚度有一定下降； 4）密封垫双道内外分布的负弯性能略优于正弯性能，密封垫双道外侧分布的负弯性能远超正弯性能； 5）密封垫分布从轴力附加弯矩和核心区混凝土高度2方面影响了接缝的抗弯刚度； [JP2]6）正弯矩下双道外侧防水性能优于双道内外的防水性能，而负弯矩下双道外侧防水性能较双道内外的防水性能差。由于具有更好的正弯性能以及至少有一侧密封垫受压的防水性能，密封垫双道内外分布的纵缝形式具有更好的适用性。
To investigate the optimal distribution of doublesealing
gaskets in largediameter shield tunnels, a refined
numerical simulation method that accounts for the detailed structure of joints
and plastic damage to concrete is utilized. The effectiveness of the method is
validated through a fullscale bending test of joints.
The analysis compares the mechanical properties and waterproofing performance
of joints with gaskets arranged outside the bolt hole(SGOH) and on both sides
of the bolt hole(SGBH). The findings are as follows: (1) The refined simulation
accurately reflects the compressionbending performance
of the joints. (2) The height, opening, and bolt stress in the compression area
of the joint progress through four stages with increasing bending moments,
thereby enhancing the bending resistance owing to the improved contact at the outer
edge of the compression side. (3) Axial force significantly influences the
retention of initial bending stiffness, showing a complex relationship in which
stiffness decreases under high axial forces. (4) SGBH exhibits slightly better
hogging than sagging performance, while SGOH exhibits significantly better
hogging than sagging performance. (5) The arrangement of the doublesealing gaskets affects bending stiffness in relation to axial
force, additional bending moments, and the height of the concrete in the core
area. (6) Under sagging moments, the waterproofing performance of SGBH is
superior to that of SGOH; however, the roles reverse under hogging moments.
SGBH, demonstrating superior positive bending and waterproofing performance
when at least one side of the gasket is compressed, is found to be more
applicable.
