窄间隙双洞隧道锚施工期安全性能分析

Safety Performance Analysis of Narrow Gap Double-hole Tunnel Anchors During Construction

目前针对隧道锚固悬索桥的极限承载能力的研究较多,但针对窄间隙双洞隧道锚悬索桥锚固隧道施工过程的稳定性和安全性的研究较少。为了分析隧道锚在窄间隙条件下施工过程的受力特点,采用FLAC3D对隧道施工过程的受力特性进行数值分析。研究表明,小川大桥的窄间隙双洞隧道应在开挖后及时进行支护施工,隧道锚在开挖过程中的变形较小,最大变形为1.6mm。施工过程中隧道基本处于受压状态,在洞底位置有小范围应力集中,但集中区域和塑性区域均很小,满足稳定性和安全性的要求。开挖过程中窄间隙隧道锚的应力变化规律可为悬索桥锚固隧道的设计和施工提供参考。

While extensive research has been conducted on the ultimate bearing capacity of tunnel-anchored suspension bridges,studies focusing on the stability and safety of narrow gap double-hole tunnel-anchored suspension bridges during the construction of the anchorage tunnel are scarce.This paper employs FLAC3D for numerical analysis to investigate the stress characteristics of tunnel anchors during construction under narrow gap conditions.The findings indicate that immediate support construction should be implemented after excavation for the narrow gap double-hole tunnels of Xiaochuan Bridge,as the deformation of the tunnel anchor during excavation is minimal,with a maximum deformation of 1.6 mm.The tunnel predominantly experiences compressive forces during construction,with a localized stress concentration at the tunnel base,yet the areas of concentration and plasticity are minimal,ensuring stability and safety.The stress variation patterns of the narrow gap tunnel anchors during excavation offer valuable insights for the design and construction of suspension bridge anchorage tunnels.