围压效应下早高强喷射混凝土对板岩隧道变形影响研究  

Research on influence of early high-strength shotcrete on deformation of slate tunnels under confining pressure effect

作　　者：刘召臣 高洁[2] LIU Zhaochen;GAO Jie(China Railway 20th Bureau Group Co.,Ltd.,China Railway Construction Transportation Development Co.,Ltd.,Suzhou 215151,China;Shijiazhuang Railway Vocational and Technical College,Shijiazhuang 050000,China)

机构地区：[1]中铁二十局集团有限公司中铁建城建交通发展有限公司,江苏苏州215151 [2]石家庄铁路职业技术学院,河北石家庄050000

出　　处：《混凝土》2025年第3期181-185,192,共6页Concrete

基　　金：河北省高等学校科学技术研究项目“灾损桥墩应急保通与永久恢复结合的快速恢复关键技术研究”(QN2024282)。

摘　　要：以西北地区某隧道为研究对象,就围压效应下早高强喷射混凝土对板岩隧道变形影响进行了研究,对于极速硬化、快速硬化和常规硬化3种工况,初期支护在变形和受力规律上表现出显著的共性特征.具体而言,提升喷射混凝土硬化速率,增强早期强度,有效抑制初期支护位移变形,但伴随初支结构受力上升,特别是在开挖上台阶阶段,沉降增速尤为显著;而下台阶施工时,围岩受到再次扰动,沉降量随测试时间的延长而持续增大.在仰拱封闭之后,变形速率逐渐趋于稳定,保持在一个相对平稳的水平,在总变形中,上台阶开挖产生的平均变形量占到一半.围岩压力在仰拱封闭成环后趋于稳定,围岩压力值处于86.5~189.5 kPa之间,断面ZK8+075最大值在拱顶,为188.5 kPa,断面ZK8+083最大值在右拱肩,为184.2 kPa.两个监测断面钢拱架内侧应力、外侧应力全部表现为受压趋势,下台阶开挖作业实施后,钢架所承受的应力虽有所提升,但增速保持在一个相对平缓的态势,直至仰拱封闭完成,钢架的应力状况方逐渐趋于稳定。It takes the Northwest X Tunnel as the research object,and studies the influence of early high-strength shotcrete on the deformation of the slate tunnel under confining pressure effect.The results show that the initial support deformation and stress law of the three working conditions of ultra-rapid hardening,ultra-rapid hardening,and conventional hardening are basically consistent.The faster the hardening rate of shotcrete,the greater the early strength,and the smaller the initial support displacement deformation,but the greater the stress on the initial support structure.There is a certain relationship between the construction process and the initial support deformation,and the settlement rate is relatively high when excavating up the steps;during the construction of the lower steps,the surrounding rock is disturbed again,and the settlement further increases with the extension of testing time.The deformation rate remains stable and tends to stabilize after the closure of the arch.In the total deformation,the average deformation generated by the excavation of the upper steps accounts for about half.The surrounding rock pressure tends to stabilize after the inverted arch is closed into a ring,with a pressure value between 86.5 and 189.5 kPa.The maximum value of section ZK8+075 is at the arch crown,which is 188.5 kPa,and the maximum value of section ZK8+083 is at the right arch shoulder,which is 184.2 kPa.The internal and external stresses of the two monitoring sections of the steel arch show a compressive trend.After the excavation of the lower step,the stress of the steel frame increases,but the growth rate is relatively slow.The stress of the steel frame gradually stabilizes with the closure of the inverted arch.

关 键 词：早高强喷射 混凝土 隧道变形 围压效应 

分 类 号：TU528.53[建筑科学—建筑技术科学]