青岛地铁上软下硬岩层区间隧道断面设计优化

Design Optimization of Metro Tunnel Section in Upper-soft Lower-hard Stratum in Qingdao City

以青岛地铁3号线宁夏路站—敦化路站化区间隧道上软下硬岩层段为工程背景,利用数值模拟对三种断面隧道施工沉降、衬砌结构受力、塑性区分布、断面开挖面积和配筋面积的变化规律进行研究,并结合模拟结果与现场监测数据对隧道开挖断面进行综合优化。研究结果表明:拱部削尖马蹄形断面能保证隧道施工安全,且断面配筋面积最小,经综合考虑隧道施工的安全性与经济性,为最优断面方案。

In the engineering background of the interval tun- nel between Ningxia Rd. Station and Dunhua Rd. Station on Qingdao metro Line 3,which crosses the upper-soft lower- hard rock stratum, the variation regularity of construction set- tlement, force of lining structure, plastic zone distribution, ex- cavation section area, steel bars area in the engineering of 3 sections are studied by using numerical simulation, and the comprehensive optimization of tunnel excavation section is studied by combining the simulation result with the field mon- itoring data. This research shows that construction safety could be guaranteed with the minimum steel bars area by taking arch sharpening horseshoe section, which is confirmed as the opti- mal section in terms of construction safety and economy.