湿喷碳素纤维混凝土在大断面黄土隧道中的应用

Application of Carbon-fibre Reinforced Wet-mix Shotcrete in Large-section Loess Tunnel

黄嶂3号隧道是新建太中银铁路全线最大断面黄土隧道,最大断面面积为193.73 m2,洞身穿越地层主要为老黄土,受黄土软弱性、离散性、湿陷性和膨胀性影响,洞周出现较大变形,造成喷射混凝土支护的破坏和失效。结合实际情况,选用碳素纤维作为湿喷混凝土的添加料,研究了配套施工工艺和质量控制方法。现场应用表明,湿喷碳素纤维混凝土能够减少喷射混凝土的回弹率,改善洞内施工环境,有力保证喷射混凝土的质量并提高喷射混凝土的残余强度。此项技术在隧道施工中起到了积极的作用,对类似工程有较强的借鉴意义。

Huangzhang tunnel 3 is the largest Section Loess Tunnel along the new-build Tai-Zhong-Yin railway with a largest section 193.73m^2. Tunnel crossing strata mostly is old loess. Due to the weak, discretized, collapse and expansion property of loess, the surrounding of tunnel apears large deformation, which results in the shotcrete support failure. Combined with actual conditions, Carbon-Fibre is added into shotcrete, and the matching construction technology and quality control method is studied. Field application shows that carbon-fibre reinforced wet-mix shotcrete method can reduce spring rate of shotcrete, improve construction environment, guarantee the quality of shotcrete and improve the residuary strength. This technique plays an active role in tunnel construction, has a reference meaning for similar projects.