What are the key safety technical points for tunnel construction support?

1. Safety standards should be implemented in tunnel construction. Work construction should focus on the careful preparation of work safety implementation standards, comprehensive planning, reasonable arrangements, standardization of command lines and operation site production facilities, and implementation of standardized management

2. Implementation The construction organization design must be based on the design requirements of the "Specifications" and "Safety Regulations" and combined with the scientific selection of excavation, support, and lining processes based on the shape, water, and quality conditions. Detailed and specific safety technical measures should be formulated and construction should be based on changes in quality conditions, supplements, and conscientious Make technical briefings on safety education

3. Tunnels with weak surrounding rock, good quality, special quality or shallow burial, partial pressure, and landslide sections should organize technical demonstrations to determine drilling and blasting, excavation, and support cases

4. Ventilation ducts, high-pressure air ducts, water pipes, lighting lines, transmission lines, transportation roads, and pedestrian roads in the cave should be planned and maintained in an integrated manner, and their layout should be neat and in good condition. Mechanical equipment should be stored in fixed locations, and materials should be stacked neatly and professionally. Responsible for safekeeping

5. The construction in the cave should be commanded by the on-duty foreperson and the excavation, lining and transportation operations should be reasonably arranged according to the construction organization design to reduce cross-interference

6. Blasting excavation should be When designing blasting using smooth blasting or pre-splitting blasting technology, parameters such as the spacing between peripheral holes and the amount of extrapolation charge must be strictly controlled to reduce surrounding rock disturbance and the number of over and under excavations

7. Special personnel should be dispatched for blasting initiation. Carry out inspections and treatment of dangerous rocks and hanging rocks, and set up supervision to confirm safety. Personnel are allowed to enter the working surface to prevent dust and reduce dust concentration

8. Temporary support should be designed with documents and specifications that are accurate and within the normal range. Shot footage distance

9. The grating arch frame shotcrete anchor support must be strictly controlled according to the design standards. Construction Records" for future reference (Appendix 5 of Technical Specifications for Railway Tunnel Construction) Check the pullout resistance of anchor rods. For every 300 anchor rods, draw 1 group with less than 3 anchor rods in each group.

10. It is necessary to change the type and standard of temporary support. It is strictly prohibited to lower the support standards at the construction site upon approval of the design and supervision by the project management department

11. Adjust the excavation and lining progress to control the length of the unlined section. Under normal circumstances, the lining working surface of the 80-meter special high-quality section should be tightened. Following the excavation working surface

12. The construction of the tunnel gate should be arranged as early as possible to fully carry out the construction of each process. In any case, after 50 meters of lining is completed, the end wall and wing wall of the tunnel gate should be lined in 100 meters (single entrance). The cave door must be built

13. The ventilation system in the cave should be designed, comprehensive dust prevention measures should be taken, the concentration of dust harmful gases should be regularly tested, ventilation facilities should formulate a maintenance and use system, and dedicated communication equipment should be prioritized for guarantee and supply

14. The power supply lines in the tunnel section must be erected according to regulations. The tunnel section must use low-voltage lighting and line cables for power supply, and should be laid overhead at fixed positions

15. Explosive equipment should be strictly used and returned. The warehouse system strictly prohibits storage outside the warehouse. On-site workers should be specifically responsible for obtaining approvals and controlling the quantity of goods returned to the warehouse

16. Special maintenance battery car driver liaisons should be established on transportation tracks and roads and should establish signal-based communication to implement calls. The response system strictly prohibits non-driver passengers from boarding transport vehicles; rail transport roads should be kept smooth and water-draining conditions should be maintained; isolation signs should be set up between carriage roads; technical standards should be clarified for the ballast unloading line on the access road outside the cave to ensure safety needs

17. Propaganda slogans and warning signs should be set up inside and outside the cave so that operators can see them everywhere to increase their awareness of three-injury safety prevention

18. Full-time security inspectors must conduct a comprehensive inspection of the construction site every shift Particular attention should be paid to strengthening the inspection of the temporary support status of the surrounding rock. Any slight changes should be recorded step by step. Problems found should be recorded step by step and the leaders should take measures to properly deal with them. The construction technical department should carefully observe and measure the deformation of the temporary support and carefully process the recorded data. Improve construction according to maintenance and support parameters

19. Tunnel construction should formulate emergency plans to prevent collapse, water inflow, gas and other emergencies, equip necessary rescue machinery and materials, clearly organize employees to take immediate measures to reduce the impact of problems when problems occur

20. Properly arrange the culture and materials of workers to create good and safe production. The air-conditioning medical room should strengthen surgical capabilities and equip necessary surgical rescue drugs and equipment. Staff hospitals should be set up in convenient transportation areas to deal with the sick and wounded