苏通GIL综合管廊工程盾构隧道管片结构安全性评估

Safety Evaluation of Shield Tunnel Segment Structure of Sutong GIL Utility Tunnel Project

为了探明高水压作用下大断面盾构隧道管片结构的安全性,依托苏通GIL综合管廊工程项目,选择5个控制断面作为研究对象,利用多功能盾构隧道结构体加载装置,对管片结构开展原型加载试验;基于混凝土结构偏心受压极限承载力理论,推导出管片结构的M-N承载力曲线,并提出管片结构的安全性评价指标。研究表明:管片结构的弯矩呈现出“蝶状”分布,轴力呈现出“圆状”分布,最大正弯矩和最大轴力均出现在拱顶位置;5个控制断面管片结构的试验内力均在承载力曲线包络范围内,管片结构均处于安全状态;管片结构安全系数沿圆周分布不均,拱顶安全系数小于其他位置,管片结构的安全系数为2.12-2.91,设计满足安全性要求。

In order to verify the safety of segment structure of large cross-section shield tunnel under high water pressure,5 control cross-sections of Sutong GIL utility tunnel project are selected as the research object to carry out prototype loading test on the segment structure by multi-functional shield tunnel structure loading device.Based on the theory of eccentric compression ultimate bearing capacity of concrete structure,M-N bearing capacity curve of segment structure is derived,and safety evaluation index of segment structure is put forward.The research results show that:(1)The bending moment of the segment structure shows a butterfly-shaped distribution,and the axial force shows a circularshaped distribution;the maximum positive bending moment and the maximum axial force appear on the crown.(2)The test internal forces of the segment structure of selected 5 control cross-sections are all within the envelope of the bearing capacity curve,which is in a safe state.(3)The safety coefficient of the segment structure is unevenly distributed along the circumference;the safety coefficient of crown is smaller than other positions;the safety coefficient of segment structure ranges from 2.12 to 2.9,which meets safety requirements.