1. This treatment scheme is mainly for large karst caves under the foundation and pavement, and the crossing treatment scheme is adopted. 2. This drawing is applicable to limestone sections or sections where water inrush and gushing may occur in fault fracture zones. The judgment standard is that the flow rate of single hole in advance exploratory hole is>2m?/h, and the total water volume is>10m?/h. 3. According to the past experience and lessons, when collapse and other accidents occur behind the tunnel face, the construction personnel are likely to be trapped in the tunnel; In order to ensure the safety of trapped personnel, implement rescue quickly and effectively, and minimize accident losses, relevant engineering measures and preparation of relevant rescue facilities and equipment shall be considered during tunnel construction. 4. This treatment plan is mainly for the sections with karst caves developed at depth less than 2.0m outside the tunnel excavation face (above the arch waist, under the foundation and pavement), and the karst caves developed at the side wall. In principle, backfilling is adopted for treatment. 5. This treatment scheme is mainly aimed at the treatment scheme that the development depth of karst cave outside the tunnel excavation face above the arch waist is more than 2.0m, and the width of karst cave is less than the tunnel excavation face. 6. This treatment scheme mainly aims at the treatment scheme for karst caves with a depth of more than 2.0m outside the tunnel excavation face above the arch waist, a width of less than that of the tunnel excavation face and a depth of more than 5.0m in the base, and a width of less than that of the tunnel excavation face. ...... Drawings include: karst treatment plan design drawing, tunnel emergency plan design drawing...... 6 sheets in total