类矩形盾构隧道设计方案研究

Research on the Design Scheme of Quasi-Rectangular Shield Tunnels

工程实践已经证明,位于软土地区的区间隧道首选施工工法是盾构法。然而随着轨道交通的迅速发展和建设,可利用的地下空间越来越有限,传统的单洞单线隧道因施工工艺的限制两隧道外包尺寸宽度较大,在道路狭窄的老旧城区部分区间隧道要下穿或近距离侧穿房屋建筑,无论在建设期还是运营期都会对建筑物产生一定的影响。随着环境保护标准的不断提高,需寻求一种合适的隧道断面,以达到地下空间集约化利用、高标准环境保护的目的。文章根据对国内外隧道断面的调研资料,并依托宁波轨道交通4号线的工程设计,从建筑横断面、管片结构形式、疏散救援等方面对类矩形盾构隧道断面型式和管片结构特点等进行了分析研究。

Engineering practice has proven that shield tunneling method is the priority to construct running tunnel in soft ground.With the rapid development and construction of rail transit projects,the available underground space is becoming limited.However,the traditional segmental tunnel accommodates only one rail transit line and requires wide section for two tunnels of up and down lines.With constraint to the narrow road in the old downtown area,the running tunnel has to drive through or be in proximity to the nearby buildings,which will exert impacts on these buildings both in construction phase and operation phase.With regard to increasingly higher standard of environment protection,a more reasonable tunnel section is being sought to realize the intense usage of underground space and high standard of environment protection.Based on the investigation of tunnel sections at home and abroad and the design of Ningbo Rail Transit Line 4,the paper studies the tunnel cross section,segment structure,evacuation and rescue modes,and proposes a new tunnel section of the quasi-rectangular tunnel structure.