Tunnel construction can be divided into mountain tunnels, underwater tunnels and urban tunnels according to the location of the tunnel. Therefore, relevant departments must ensure the safety of their construction personnel. At present, with the extensive application of aerial survey, remote sensing technology, geophysical technology, measurement technology, electronic computer technology, etc., the technical level of tunnel survey and design has also been greatly improved. Accurate blasting technology, horizontal drilling technology and pre-grouting technology continue to improve, it is possible to improve the safety of the tunnel excavation process, and can ensure the quality of tunnel engineering, while also ensuring the safety of construction to a certain extent.
Organizational assurance measures
Establish a production safety leadership group led by the project manager to be fully responsible for the safety production work of this project. The deputy manager in charge of safety production is the direct person in charge of safety production, and the chief engineer is the technical person in charge of safety production. Management personnel and production personnel who have not passed the safety education and training and passed the examination are not allowed to work.
System guarantee measures
① The safety production responsibility system must be strictly implemented. All levels and departments must have clear safety responsibilities, and there must be safety production indicators in economic contracts.
② Implement the three-level safety education system and register. Before changing the type of work or process, you should receive safety education about the process you are engaged in.
③All special operations personnel (blasters, electric welders, etc.) must be certified to work, and non-special workers are strictly prohibited from engaging in special operations.
③Regular safety inspection system must be implemented, and each inspection must be recorded to identify hidden accidents; rectification must be ordered, time, and measures, and the rectification notice for major hidden dangers must be completed as required.
④ Personnel entering the construction site must wear safety helmets. Personnel working in dangerous and high-altitude operations must wear labor protection equipment and safety equipment as required.
Technical guarantee measures
1. The construction site must be designed according to the construction organization to do a good job of “three connections and one leveling” large-scale components, reasonable and orderly stacking of materials, eye-catching slogans, publicity boards, safety measures, and safety signs on site.
2. Participants in construction must go through safety education, be familiar with the safety operating procedures of this type of work, and hold certificates for special operations. Abide by the operating procedures at work and stick to the job position. It is strictly prohibited to work after drinking.
3. Use safety protection products and safety protection measures correctly. Personnel entering the construction site must wear safety helmets. High heels, slippers, hard-soled slippery shoes are not allowed. Safety belts must be worn when working at high places without protective facilities. Protective railings, baffles or safety nets are required for operations in spaces above 2 meters from the ground.
4. Dangerous places such as pits, ditches, holes, and wells on the construction site should be protected, and there should be red warning lights.
5. The material of scaffolding, pole foundation, pole cabinet, sweeping pole, pole connection, outer protection, scaffolding board laying, etc. must meet the requirements of regulations. Set up by professional shelf workers. Remove the scaffold gradually from top to bottom, and it is strictly forbidden to remove it by overturning or pulling down. Do not work up and down at the same time. It is strictly forbidden to put the removed materials.
② Process construction safety measures
1. For tunnel construction, the pre-construction preparations should be done, the construction method should be correctly selected, and the construction technical plan should be compiled in combination with the actual conditions such as topography and geology, and the construction personnel should be technically informed to rationally arrange the construction.
2. A complete shift system should be established between each team in tunnel construction. When handing over the shift, the shift person should give the successor a detailed account of the construction situation and related safety issues and measures of the shift and group, and record it in the handover record book. The person in charge of the work site (leader) should carefully check the handover situation . Construction is not allowed if the safety status of the working face is not carefully checked before the start of each shift.
3. Strengthen inspection and measurement of surrounding rock during construction. For tunnel construction in poor geological sections, a small cycle construction method such as weak blasting, short excavation, strong support, early lining, and top protection should be adopted. Tunnel construction must make full use of monitoring methods to predict and forecast the surrounding rock displacement and the force status of the supporting structure, and the measurement must serve production safety.
4. If there is a dangerous situation in the tunnel, it is necessary to set up obvious signs or send a special person to guard the dangerous area, and promptly report to the person in charge of the construction site, and take timely measures to deal with it. When the situation is dangerous, all the staff should be evacuated from the dangerous area and immediately Reported.
5. All personnel entering the tunnel construction site must be equipped with safety protection equipment according to the regulations, and obey the command.
6. Do not dig into the hole if the opening of the hole has not been painted on the slope or the roof of the hole has not been protected and drainage facilities have been installed.
7. Drilling on the tunnel face
(1) When drilling personnel arrive at the work site, they should first check whether the working surface is in a safe state, such as whether the support, roof and two sides are firm. If there are loose rocks, they should be supported or treated immediately.
(2) Wet rock drilling must be used when drilling a hole with a trolley and a rock drill.
(3) It is strictly forbidden to continue drilling in the residual eye.
(4) Do not disassemble and repair rock drilling equipment at the working face.
8. Blasting operations
(1) The blasting operation in the cave must be certificated and commanded uniformly.
(2) When blasting, all personnel must be evacuated outside the warning zone protected from harmful gas, vibration and flying rocks, and safety guards should be set up. The safety guard distance should comply with relevant regulations.
a. No less than 100m in the Dutou tunnel;
b. The adjacent upper and lower pilot pits are not less than 200m;
c. Do not use TNT (trinitrotoluene), picric acid, black gunpowder and other explosives that generate a large amount of harmful gas for blasting in the cave. After blasting, ventilation and smoke must be exhausted for 15 minutes before other workers are allowed to enter the working surface.
d. If a blind cannon is found, it must be handled by the original blasting personnel according to regulations.
e. It is strictly forbidden to carry out explosive processing work outside the explosive processing room, and processing personnel are strictly forbidden to wear chemical fiber clothing. The daily firing time and frequency should be clearly stipulated according to the construction conditions, and the time to fire after charging should not be too long.
(1) All parts of the tunnel shall be supported immediately after excavation.
(2) During the construction period, the person in charge of on-site construction I should conduct regular inspections on the support of each department in conjunction with relevant personnel. In bad geological areas, each shift should be instructed to inspect by special personnel. When the support is found to be altered or damaged, it should be repaired and reinforced immediately.
(3) When the sprayed concrete has not reached a certain strength, the surrounding rock that tends to become unstable, or the surrounding rock whose deformation exceeds the design allowable value and sudden changes after spray anchoring, should be supported by steel support.
(4) When installing the steel frame support, the relevant safety rules such as lifting and high-altitude operations should be observed, and small equipment should be used for hoisting.
(5) For surrounding rock with poor self-stability after excavation, the method of using advanced bolts and hanging nets to spray concrete should be used for temporary support.
(6) The abnormal cracks in the sprayed layer should be regarded as one of the main safety inspection contents, and frequent observation and inspection should be performed as a danger signal for construction to cause vigilance.
(7) For concrete spraying and grouting operations, you must bring protective equipment as required.
10. Ballast loading and transportation
(1) Before and during ballast loading, check the stability of the surrounding rock of the excavation surface. When loose rock or signs of collapse are found, the ballast must be treated first and then loaded.
(2) It is proposed to use a loader to load the ballast. During the construction process, no one can pass within the mechanical swing range. Prevent crowding with people.
11. Secondary lining
(1) Railings of no less than 1m should be erected on the lining workbench, anti-skid strips should be set up on the springboard, and the ladder should be installed firmly without nails outcropping and protruding sharp corners.
(2) The load-bearing capacity of workbenches, springboards, and scaffolding should not be overloaded, and should be marked on the spot. The scaffolding and the bottom plate of the workbench should be laid tightly, and the ends of the wooden boards must be placed on the fulcrum.
(3) When hoisting arches and model plates, the working area should be supervised by a dedicated person.
(4) When dumping the lining material in the operation section of the tunnel, personnel and vehicles are not allowed to pass through.
(5) When working at heights above 2m, the relevant regulations for working at heights shall be met.
(6) To check and repair the squeezing machine and pipeline, shut down and cut off the air source and power source.
(7) When removing the concrete conveying hose or pipeline, the operation of the concrete pump must be stopped.
(1) Comprehensive dust prevention measures must be adopted for tunnel construction, and dust concentration must be checked regularly.
(2) The following dust prevention work must be done in tunnel construction on the rock drilling and ballast loading face:
a. Spraying and watering must be carried out before and after the shot;
b. Use water to soak the ballast pile and spray wet the rock wall before the ballast is discharged.
13. Power supply and electrical equipment
(1) Construction machinery, machinery and electrical equipment should be tested in accordance with safety technical standards before installation, and can be installed only after passing the test, and can only be operated after confirming that the condition is good.
(2) The voltage of the tunnel construction lighting circuit is not greater than 36V in the construction area. All power equipment shall be inspected and maintained by special personnel, and warning signs shall be set.
(3) When operating electrical equipment in the cave, the following requirements must be met:
a. Non-full-time electrical operators shall not operate electrical equipment.
b. When operating the main circuit of high-voltage electrical equipment, you must wear insulating gloves, electrician insulating rubber shoes and stand on the insulating board.
c. The operating handle of hand-held electrical equipment and the parts that must be contacted during work must have good insulation, and insulation inspection should be carried out before use.
d. Low-voltage electrical equipment should be equipped with electric shock inspection.
(4) Electrical equipment must have good grounding protection, and each shift shall be inspected by a full-time electrician.
(5) The inspection, maintenance and adjustment of electrical equipment must be carried out by a full-time electrical maintenance worker.
(6) The lighting in the cave should ensure sufficient brightness, uniformity and no flicker. For warehouses or caverns with flammable, explosive and other dangerous goods, explosion-proof lamps or indirect lighting must be used.
14. Emergency plan
It is inevitable that emergencies will occur during the construction process, so it is necessary to formulate practical emergency plans to prevent emergencies. For every possible accident or emergency, the person in charge of the scene can report to the higher level and immediately direct the handling of the emergency on the spot.