山岭隧道不同埋深的结构动力响应特征及震害机理研究

Research on the Characteristics of Structural Dynamic Response and the Seismic Mechanism of Mountain Tunnels with Different Depths

震害调研表明了不同埋深时隧道破坏的差异性较大。基于此,对隧道洞门区域的典型震害特征及破坏机理进行分析;通过建立三维有限元数值模型,基于土-结构之间的相互作用关系,重点研究洞门浅覆土区域隧道结构在不同埋深下的地震动力响应及隧道衬砌的破坏机理。结果表明:土-结构相互作用关系对隧道衬砌的受力变形起控制作用,地层的剪切变形可以直接反映衬砌的变形模式及地层振型特征;土-结构相互作用力、围岩塑性变形及衬砌结构的损伤分布均表明拱腰及拱脚等区域对隧道结构的整体稳定性起控制作用,建议对该区域围岩进行加固。

Seismic studies have shown that damages could vary greatly to tunnels with different depths.In view of this,this paper analyzes the typical seismic characteristics and damage mechanisms at the tunnel portal area.By establishing a 3D finite element numerical model,this paper is based on the soil-structure interaction with a focus on the ground seismic response of the tunnel structure in the shallow overburden area at the portal with different depths and the damage mechanism of the tunnel lining.The results show that the soil-structure interaction plays a controlling role in the force-induced deformation of the tunnel lining,and the shear force-induced deformation of the strata can directly reflect the deformation mode of the lining and the characteristics of the stratum vibration pattern.In addition,the force of the soil-structure interaction,the plastic deformation of the surrounding rock and the damage distribution of the lining structure all indicate that different areas,such as the side and foot of the arch,play a controlling role in the overall stability of the tunnel structure,and it is recommended that the surrounding rock in these areas be reinforced.