摘要
管片错台引起的结构损伤极大影响隧道施工和服役期间安全性,因此管片接头抗剪性能是研究盾构隧道结构力学特性的重要内容。为探明高水压下小断面盾构隧道的环间抗剪性能,依托某输气管道盾构隧道,开展纵向接头抗剪足尺试验和数值模拟,分析不同工况下错台的力学特征,探究管片接头受剪过程和承载机理。研究表明:弯螺栓-凹凸榫式管片接头受剪突破静摩擦阶段后,顺剪和逆剪的力学性能较为接近,但顺逆剪时螺栓和凹凸榫失效区域有所不同;螺栓孔附近混凝土在和螺栓协同变形的过程中,发生与左右试件各自错动方向相反的失效区域扩展,同时在螺母位置附近出现小范围屈服区域;纵向接头抗剪的主要承载部位是螺栓和凹凸榫,凹凸榫的抗剪作用主要体现在相互咬合,但也会导致接头发生滑移和局部应力集中明显;相比单一管片型式,螺栓结合凹凸榫能延迟螺栓达到极限强度的时机,有助于整体提升接头抗剪性能。
The structural damage caused by segment dislocation greatly affects the safety of tunnel in construction and service stages.Therefore,the shear performance of segment joints is an important content to study the mechanical properties of shield tunnel structure.In order to explore the inter-ring shear performance of a small section shield-driven tunnel under high water pressure,this paper carried out full-scale shear test and numerical simulation of longitudinal joint based on a shield-driven gas transmission tunnel,analyzed the mechanical characteristics of dislocation under different working conditions,and explored the shear process and load-bearing mechanism of segment joint.The results show that the mechanical properties of the segment joint with the curved bolt and concave-convex tenon during ordinal sheading are like those during the reverse shearing after the shear breaks through the static friction stage,but the failure areas of the bolt and concave and convex tenon are different during the shearing.In the process of co-deformation of the concrete near the bolt hole with the bolt,the failure zone expands in the opposite directions of the dislocation directions of left and right specimens respectively,and a small yield zone appears near the bolt nut position.The main shear bearing parts of longitudinal joints are bolts and tenons.The shear action of tenons is mainly reflected in mutual occlusion,but it also leads to joint slip and obvious local stress concentration.Compared with a single segment joint type,the combination of bolts and tenons can delay the time when the bolts reach their ultimate strength,helping to improve the overall shear performance of the joint.
作者
张景轩
方砚兵
封坤
李博
周子扬
张力
ZHANG Jingxuan;FANG Yanbing;FENG Kun;LI Bo;ZHOU Ziyang;ZHANG Li(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031)
出处
《现代隧道技术》
CSCD
北大核心
2022年第S01期573-582,共10页
Modern Tunnelling Technology
关键词
输气盾构隧道
新型连接构造
抗剪性能
数值模拟
足尺试验
Shield-driven gas transmission tunnel
New connection structure
Shearing strength
Numerical simulation
Full-scale test
作者简介
张景轩(1995-),男,博士研究生,主要从事隧道与地下工程方向研究方面研究,E-mail:cheungjens@126.com.
