基于预制箱梁过隧道的几何相容性安全研究

Safety investigation of geometric compatibility basedon prefabricated box girder during transit through tunnels

针对目前客运专线建设过程中存在预制箱梁无法通过隧道的问题,提出预制箱梁过隧道几何相容性安全分析的原则、流程和方法。指出预制箱梁过隧道几何性相容性安全分析,应按照以安全距离为约束,以主体结构完整性为保障,尽量以施工调整为主,避免设计变更;以隧道最大净宽为目标,选择适宜仰拱填充混凝土预留高度;分析隧道内进出口,隧道内变坡点等断面,能否保证通行;检查运梁车运行纵坡,是否满足运梁车爬坡要求;仰拱填充混凝土预留槽口后浇筑,可以作为首选方法之一;预制箱梁穿隧道过程,要预防箱梁撞击隧内壁事故,对于箱梁穿隧道有一定借鉴意义。

At present,an issue exists in the process of passenger dedicated line construction,which is that a prefabricated box girder cannot pass through a tunnel.Therefore,this study proposed the principles,procedures and approach of safety analysis for the geometric compatibility of a prefabricated box girder passing through a tunnel.The safety analysis follows the“safe distance constraint”,and primarily safeguards the integrity of the main structure and takes auxiliary engineering adjustment as the main goal.The goal of the safety analysis is to maximize the net width of the tunnel and select an appropriate reserve height.It analyzes the minimum cross section,verifies the grade change point and checks the longitudinal gradient.In addition,pouring is conducted after reserving the slots,where the intrinsic safety relies on its deformation.Using the safe distance as the constraint,the box-girder transport speed was selected.Taking collision as the intrinsic safety when a prefabricated box girder passes through a tunnel,this article clarifies the procedures for the safety analysis of geometric compatibility.It also proposes that pouring after filling the tunnel invert can be regarded as one of preferred approaches for adjustment.