硫酸盐侵蚀下交叉盾构隧道动力响应分析

Dynamic Response Analysis of Cross Shield Tunnel under Sulfate Attack

基于硫酸盐侵蚀作用下混凝土弹性模量与抗压强度随时间的变化关系,通过数值建模,研究硫酸盐在不同侵蚀年限下交叉盾构隧道的动力响应特性。结果表明:交叉盾构隧道的应力响应在硫酸盐侵蚀21.4年时达到最小,相比于未侵蚀时减小11.7%,而在107.1年时应力响应增大18.5%;衬砌结构的加速度响应在硫酸盐侵蚀21.4年时达到最小,相比于未侵蚀时减小2.3%,在107.1年时加速度响应增大17.4%。联络横通道的存在对主隧道结构受力影响较大,使主隧道管片环的刚度奇异性增大,从而导致该区域结构受力复杂。

Depending on how the elastic modulus and compressive strength of concrete change with time under sulfate attack,herein by means of numerical modeling the characteristics of dynamic response of cross shield tunnel in different years of sulfate attack were studied.The result shows that the stress response of cross shield tunnel is minimal in case of sulfate attack for 21.4 years and,compared to the case without sulfate attack,11.7%is cut down,while at the time of 107.1 years,the stress response will increase by 18.5%;the acceleration response of lining structure is minimal in case of sulfate attack for 21.4 years and,compared to the case without sulfate attack,2.3%is cut down,while at the time of 107.1 years,the acceleration response will increase by 17.4%;the existence of connecting cross passage has relatively large impact on the stress of the main tunnel structure,leading to increased singularity of the segment rings’stiffness and stress complex of the structures in this area.