明挖区间隧道无柱大空间预应力结构设计

Prestressed structural design of no-column-supported large space for open excavated tunnels

提出3种无柱大空间预应力区间结构方案,并选取预应力密排框架箱形结构方案。针对该方案,通过完成内张拉预应力技术研究、有限元计算分析优化、结构构件设计计算和验算、新方案和普通方案构件承载力设计值与荷载效应组合设计值的对比等,得出预应力密排框架箱形结构方案设计安全可靠,可满足地铁明挖区间无柱大空间区间隧道要求,并为地铁明挖无柱大空间车站结构设计提供借鉴。

Three prestressed structural design schemes are proposed for the no-column-supported large space for a heavy-load tunnel.Box structure with densified frames is chosen through comparison.Further analysis is performed including inner tensioned prestressing technology research,FEM analysis,structural component design and verification,comparison of design bearing capacity and design value of load combination effect of structural components for the new and old design schemes.It is indicated that the prestressed box structure with densified frames is capable of providing no-column-supported large space for open excavated tunnels with sufficient safety and reliability.This design scheme is also a design reference for similar engineering design.