학술논문
缓倾软岩地层隧道仰拱超挖对结构受力影响 / Influence of Inverted Arch Over-Excavation on the Structural Stress of Tunnel in Gently Inclined Soft Rock Strata
Document Type
Academic Journal
Source
铁道建筑技术 / Railway Construction Technology. (2):169-172
Subject
Language
Chinese
ISSN
1009-4539
Abstract
本文以贵南铁路九万大山一号隧道为依托工程,为掌握缓倾软岩地层隧道仰拱超挖对结构受力的影响,运用现场测试技术手段分两种工况开展典型仰拱断面监测工作:(1)仰拱爆破后,直接架设拱架再喷射混凝土形成初期支护;(2)仰拱爆破后,先喷射混凝土填补超挖部分,使隧道仰拱精确成型,再架设钢架,确保钢架与围岩密贴,最后喷射混凝土形成初期支护.对两种工况分别测试仰拱围岩压力、钢架及混凝土应力以分析仰拱超挖处理前后结构受力特征,并对初喷工序在大断面缓倾岩层隧道修建中所起作用进行验证.
Based on No.1 Tunnel of Jiuwandashan of Guiyang-Nanning Railway,in order to grasp the influence of over-excavation of tunnel in gently inclined soft rock stratum on structural stress,the field testing technique was used to monitor the typical inverted arch section under two working conditions:(1)after the inverted arch blasting,the arch frame was directly erected and then the concrete was sprayed to form the initial support;(2)after the inverted arch blasting,the over-excavated part of the tunnel was filled by spraying concrete to make the tunnel overarched accurately,then the steel frame was erected to ensure that it adhered closely to the surrounding rock,and then the initial support was formed by spraying concrete.The surrounding rock pressure,steel frame and concrete stress of the inverted arch under two working conditions were tested respectively to analyze the structural stress characteristics of the inverted arch before and after the over-excavation,and to verify the role of the initial spraying process in constructing the tunnel in gently inclined rock stratum with large cross-section.
Based on No.1 Tunnel of Jiuwandashan of Guiyang-Nanning Railway,in order to grasp the influence of over-excavation of tunnel in gently inclined soft rock stratum on structural stress,the field testing technique was used to monitor the typical inverted arch section under two working conditions:(1)after the inverted arch blasting,the arch frame was directly erected and then the concrete was sprayed to form the initial support;(2)after the inverted arch blasting,the over-excavated part of the tunnel was filled by spraying concrete to make the tunnel overarched accurately,then the steel frame was erected to ensure that it adhered closely to the surrounding rock,and then the initial support was formed by spraying concrete.The surrounding rock pressure,steel frame and concrete stress of the inverted arch under two working conditions were tested respectively to analyze the structural stress characteristics of the inverted arch before and after the over-excavation,and to verify the role of the initial spraying process in constructing the tunnel in gently inclined rock stratum with large cross-section.