Abstract: The fullface rock boring machine works inefficiently in extremely complex geology. To solve the problem, based on the consideration of extremely complex geological environment conditions and technical characteristics of fullface rock boring machine, the following work were done: First, technical indexes of fullface rock boring machine in extremely complex geology are formulated, and the fullface rock boring machine for extremely complex geology is developed, and the expanding excavation technology for variable crosssection convergence stratum is proposed. Second, in view of the geological characteristics of broken surrounding rock, the cooperative operation methods of key parameter control, small tube chemical grouting, pipe shed grouting and small pilot tunnel excavation technology are established, which are applied to solve the broken surrounding rock stratum; Third, aiming at the problem of low efficiency of rock slag accumulation excavation, the combined slag removal mode of mechanical slag removal and belt conveyor slag removal is established; Finally, the extremely complex geological excavation in Gaoligong Mountain verified the research results. The results show that: (1) The full face Hard Rock Roadheader has high footage speed and high equipment integrity rate in class II and III surrounding rock conditions. (2) The broken stratum mainly composed of class IV and V surrounding rock has good adaptability, and the maximum monthly footage reaches 438 m and the average monthly footage is 412 m under the general condition of tool wear, indicating that it has good geological adaptability.

Key words: extremely complex geology, full face hard rock roadheader, support system, weak and broken strata, key technology, tunneling performance analysis, railway tunnel