1. The workers engaged in the underground operation of digging piles shall be healthy young men who have passed the physical examination and have passed the safety operation training in underground, high altitude, electricity consumption, lifting and simple mechanical operation, etc., before entering the site construction.

2. Before drawing review and pile hole excavation, geological drilling data should be carefully studied and analyzed, and corresponding safety protection measures should be formulated for possible sand flow, pipe trench, trench water and harmful gas. If there is any doubt about safety, it should be reported to the relevant unit in advance.

3. All equipment, facilities, safety devices, tools, accessories and personal labor protection articles on the construction site must be inspected frequently to ensure that they are in good and safe state.

4. The electric hoist and hanging cage used by the staff in the pile hole must be qualified mechanical equipment, and should be equipped with automatic clamping safety device. Do not use artificial pull rope to transport workers or step on the upper and lower pile holes at the edge of the wall. Electric hoist to use button switch, before work, after work should have a strict inspection and maintenance, before use must test its safety lifting capacity. A soft ladder or nylon rope must be placed in the pile hole and extended to the working face as the digging depth increases for emergency.

5. After the excavation of the pile hole, pay attention to the changes of the ground and surrounding buildings (structures). If the pile hole is near the building or dangerous house, reinforcement measures must be taken before construction.

6, excavated earth and stone should be carried away in time, the hole around the 2m range shall not pile up mud and debris. When motor vehicles are passing, preventive measures should be taken or operations in the hole should be suspended to prevent squeezing and collapsing the hole.

7. When the excavation depth of pile hole is more than 5m, toxic gas should be detected before starting every day. It is generally appropriate to use instruments for detection, or simple methods can be used, such as placing pigeons in birdcage at the bottom of pile hole for no less than 10 minutes.

8, every day before the start of work, the pile hole should be drained of water, and the air blower or big fan to the hole for 5 minutes, so that the turbid air in the hole is discharged, before the human. When the hole depth reaches 10m, the ground should be equipped with special equipment for air supply in the hole, and the air volume should not be less than 25L/S. When drilling in the hole, the air supply should be increased.

9. In order to prevent ground personnel and objects from falling into the pile hole, the protective wall of the hole mouth should be 20cm above the ground.

10, underground operation personnel must wear safety helmet, wear insulation rubber shoes, strictly prohibit drunk work, do not smoke in the hole and use open fire, operation personnel should rotate every 4 hours. When it is found that sand flow, ditch water, wall shape and other adverse signs, as well as odor gas, the operation should be stopped immediately and quickly evacuated from the well.

11. When excavating complex soil layer, every 0.5~1m, hand drill or not less than φ 16 steel bar should be used to inspect the bottom of the hole and check whether there are caves and trench sand under the hole. After confirming safety, the operation can be continued.

12. When the pile hole is dug below 5m, a semi-circular steel (wood) protective cover shall be set 3m above the bottom of the hole. When the bucket is up and down, the operator must stand under the protective cover, and when the large stone is lifted, the personnel in the hole should be evacuated from the hole before lifting.

13. When drilling in the hole, wet operation method should be adopted, and ventilation and dustproof and personal protection should be strengthened. In the middle of pumping water, all the operators in the hole should be evacuated, and the operation can be carried out after cutting off the power supply.

14, such as blasting in the hole, the operators in the hole must be evacuated before detonating, blasting, the hole should be capped, after blasting must be pumped, air supply or water and other methods to remove the exhaust gas in the hole, before the operation of the hole.

15. The orifice cooperating personnel shall closely monitor the operation in the orifice and shall not leave the post without permission. It is strictly forbidden to use throwing method when delivering tools and articles in the hole. Prevent objects from falling into the hole.

16, construction power supply, electrical installation and removal, must be licensed electrician, electrical appliances must be strictly grounded, zero and the use of leakage protector. After the installation of electrical equipment can be connected to the power supply. Each hole must be divided into sluice, it is forbidden to use the same sluice. The wires and cables above the holes must be on the ground, and it is forbidden to drag the ground or bury them in the ground. The cables inside the holes must be insulated reliably, and be protected against abrasion, moisture and breakage. Safety mine lamp or safety lamp below 12V shall be used for lighting operation in the hole.

17. When pouring concrete into pile body, the digging operation within 10m of the adjacent hole shall be stopped, and no one shall be left at the bottom of the hole.