复杂应力路径下波纹钢加固盾构隧道数值分析

Numerical analysis of corrugated steel reinforced shield tunnel under complex stress path

为探究复杂应力路径下波纹钢加固盾构隧道受力变形规律的异同和加固效果,基于MIDAS GTS NX有限元软件构建三环错缝精细化模型,从管片加固前后收敛变形量、波纹钢应力、管片塑性变形等角度衡量波纹钢加固效果,对比分析堆载、卸载工况下波纹钢加固盾构隧道受力变形演化规律。研究结果表明:复杂受荷环境下管片最大收敛变形部位分布不同,堆载以腰部收敛为主,卸载以顶底部竖向收敛为主;卸载下施作波纹钢加固效果优于堆载工况,最大加固效率可达70%;堆载与卸载工况下,不同板厚波纹钢加固管片的收敛变形、波纹钢应力发展规律类似且均呈现线性增长趋势;波纹钢能有效延缓混凝土塑性发展态势,但对于卸载工况下的环间错台抑制能力较弱.

In order to probe into the similarities and differences of the stress-deformation law and the reinforcement effect of shield tunnel strengthened with corrugated steel under complex stress paths,a refined model of three-ring stag-gered joints was established based on the finite element software MIDAS GTS NX,the effect of corrugated steel rein-forcement was evaluated from the angle of convergent deformation,corrugated steel stress and plastic deformation of segments before and after reinforcement,the stress and deformation evolution of shield tunnel strengthened with corruga-ted steel under loading and unloading conditions were analyzed.The results showed that the distribution of the maximum convergent deformation was different in the complex loading environment.The waist was the main part of the loading,and the top and bottom was the main part of the unloading under unloading,the effect of corrugated steel reinforcement was better than that under surcharge loading,and the maximum reinforcement efficiency could reach 70%,the conver-gent deformation and the stress development of corrugated steel with different plate thicknesses were similar and showed a linear increasing trend,while corrugated steel could effectively delay the plastic development of concrete,however,the ability of stagger suppression between rings under unloading condition was weak.