摘要
本文建立了按喷射混凝土早期性能确定隧道合理施工进度的研究方法,依托高原铁路通麦隧道,研究了微台阶开挖的V级围岩大断面隧道中不同施工进度安排的合理性,施工进度为2.5 m/d时初期支护不安全;施工进度为0.5 m/d时,初期支护安全但进度太慢会影响工期;施工进度为1.0 m/d时,需要通过适当提高喷射混凝土8 h龄期的抗压强度,或适当增加上台阶的喷射混凝土厚度,以及在上下台阶的分界处采取局部加强措施,在此前提下通麦隧道微台阶开挖在V级围岩段施工进度定为1.0 m/d是可行的。研究还发现:在V级围岩中,控制施工进度的是8 h龄期的喷射混凝土抗压强度,因此,只要通过调整混凝土配比以增加其8 h龄期早期性能,就可以加快施工进度。
A research method is established to determine the reasonable of the tunnel according to the early performance of shotcrete. Relying on the Tongmai Tunnel of the Plateau Railway, the rationality of different construction schedule arrangements in the V-level surrounding rock large-section tunnel excavated with micro-steps is studied. The study shows that: When the construction progress is 2.5 m/day, the initial support is not safe;when the construction progress is 0.5 m/day, the initial support is safe, but the progress is too slow, which will affect the construction period;when the construction progress is 1.0 m/hour, it is necessary to appropriately increase the compressive resistance of the shotcrete at the age of 8 hours. Strength, appropriately increase the thickness of shotcrete on the upper steps, and take local strengthening measures at the boundary between the upper and lower steps. Under this premise, it is feasible to set the construction progress of the V-level surrounding rock section of the Tongmai Tunnel micro-step excavation at 1.0 m/day. The study also found that. in the V-level surrounding rock, the compressive strength of the shotcrete at the age of 8 hours is the control of the construction progress. Therefore, as long as the concrete ratio is adjusted to increase its early performance at the age of 8 hours, the construction progress can be accelerated.
作者
王占东
夏才初
何修涵
曹善鹏
Wang Zhandong;Xia Caichu;He Xiuhan;Cao Shanpeng(Shaanxi Railway and Underground Traffic Engineering Key Laboratory Zhejiang(FSDI),Xi'an 710043,P.R.China;Institute of Rock Mechanics Ningbo University,Ningbo,Zhejiang 315211,P.R.China;College of Civil Engineering Tongji University,Shanghai 200092,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2022年第3期955-963,共9页
Chinese Journal of Underground Space and Engineering
基金
中国铁建股份有限公司科技重大专项(2019-A04)
中铁第一勘察设计院科研项目(院科(川藏)19-19)。
关键词
铁路隧道
施工进度
喷射混凝土
8
h龄期早期性能
时空效应
微台阶开挖
railway tunnel
construction schedule
shotcrete
early performance at the age of 8 hours
time-space effect
micro-step excavation
