为解决敞开式TBM在高压富水软弱破碎蚀变构造带不良地质条件下围岩变形、钻孔困难、支护困难、刀盘被卡、护盾被卡、突涌掩埋设备等工程难题，结合大瑞铁路高黎贡山隧道2台敞开式TBM在滇西南极端复杂地质条件下的施工情况，以PDZK221+481处高压富水软弱破碎蚀变构造带处治为例，从初期支护加固措施、钻孔技术、超前加固措施、侧壁导坑泄水降压措施、TBM卡机脱困技术、不良地质掘进支护措施等关键技术方面进行研究。总结出对于此类不良地质，可采用高位小导洞探测地质、侧壁导坑超前泄水降压、原位超前管棚及注浆加固、盾体区域扩挖释放护盾脱困、掌子面化学注浆加固后清理刀盘周边释放刀盘脱困、初期支护加强等综合处理技术通过，同时提出侧壁导坑断面形式及支护措施、管棚工作室断面及支护措施、超前加固支护措施等。
When opentunnel boring machine (TBM)
boring through a highpressure waterrich weakfracture altered structural belt,
problems, such as surrounding rock deformation, difficult borehole drilling,
difficult support, cutterhead jamming, shield jamming, and mud burstcaused shield burial, are often encountered. Two openTBMs were applied to the Gaoligongshan tunnel of the DaliRuili railway in extremely complex strata in southwest Yunnan, and
they crossed highpressure waterrich weakfracture altered structural belts
at section PDZK221+481. Research is conducted on key TBM construction
technologies, i.e. primary support reinforcement measures, drilling technology,
advanced reinforcement measures, sidewall heading depressurization measures,
TBM jammingrelease technology, and adverse geology
tunneling and support measures. Then, some corresponding countermeasures, such
as geological detection with a high small pilot tunnel, advanced drainage
depressurization with sidewall heading, insitu
advanced pipe roof and grouting reinforcement, jamming release with shield
expanding excavation and release, and cutterhead jamming release with cleaning
periphery of the cutterhead after chemical grouting reinforcement of the tunnel
surface, and primary support strengthening, are taken. Moreover, the crosssection form and support measures for the sidewall heading and pipe
roof chamber, and support measures for advanced reinforcement are put forward.
