深埋隧道穿越围岩破碎带变形控制技术研究

Research on Deformation Control Technology of Deep-buried Tunnel Crossing Fractured Surrounding Rock

新建和顺至邢台铁路天河山隧道为深埋隧道,隧道穿越高地应力区。隧道开挖引起局部地应力释放,在开挖围岩区域形成较大的二次应力,如不及时采取合理的支护措施,待二次应力场发展到一定程度后可能引起隧道坍塌,造成人员伤亡和经济损失,参考国内类似工程并结合设计要求,确定了拱顶沉降不超过7 mm的控制标准。本文利用FLAC3D有限差分软件分析了不同支护措施(超前小导管注浆、管棚注浆、掌子面超前注浆)对隧道变形的控制效果。结果表明:隧道采用洞身管棚、超前小导管注浆并加固掌子面的超前支护措施控制效果最好。

The newly built Tianheshan Tunnel on the Heshun-Xingtai Railway is a deep-buried tunnel,which passes through a high ground stress area.Tunnel excavation causes local in-situ stress release and forms large secondary stress in surrounding rock area.If reasonable supporting measures are not taken in time,tunnel collapse may occur after secondary stress field develops to a certain extent,resulting in casualties and economic losses.Referring to similar projects in China and combining with design requirements,the control criteria for vault settlement not exceeding 7 mm are determined.In this paper,FLAC3D finite difference software is used to analyze the control effect of different supporting measures(advance small pipe grouting,pipe shed grouting and face grouting)on tunnel deformation.The results show that the best control effect is to adopt advanced support measures such as tube shed of tunnel body,advance small pipe grouting and strengthening the face of tunnel face.