1. Acceptance of finished piles
After the PHC piles are transported to the site, the relevant quality assurance information of the piles provided with the ship will be submitted to the supervision engineer. Together with the supervision engineer, the appearance, length, quality, and relevant assurance information of the provided PHC piles and steel pipe piles will be inspected and accepted. Piling construction can only be carried out after passing the qualification.
2. Other preparation work
1. Do a good job in issuing navigational notices and piling ships to anchor in position.
2. Complete the information and qualification inspection of relevant construction ships and operating personnel;
3. Before pile sinking, review the baseline and calculate the pile position.
4. Provide three-level safety education and safety technical explanations to relevant operating personnel.
3. Hanging piles
Since the PHC piles in this project are relatively long, the four-point lifting method should be used when lifting. During the process of bolting the steel rope to the hook, avoid the piling ship’s steel rope from dragging on the pipe pile, and wrap the auxiliary steel rope with a rubber tube to ensure that the pipe pile is not scratched by the steel rope. When lifting, retract the rope slowly and evenly, and at the same time tap the wire rope gently so that it does not slide around the pile body and change its position. The main and auxiliary hooks of the piling ship rise simultaneously to raise the pipe piles to a height sufficient for moving the ship. By tightening the anchor cable and roughly positioning it according to the “Offshore Piling GPS Positioning System”, the piling ship is moved to the vicinity of the pile position to prepare for piling.
4. Setting up stakes
The main hook rises and the auxiliary hooks descend. As the degree of descent increases, the auxiliary hooks are removed one by one to make the PHC pipe pile vertical. The pile frame is tilted backward to make the PHC pipe pile and the pile frame slideway parallel. The pile holder closes the pile and locks it. The replacement driver slides along the pile frame track and covers the top of the pile.
5. Positioning
At the beginning of the pile driving stage, conventional pile driving positioning is mainly used, supplemented by GPS. Conventional positioning is used to check the alignment rate of GPS pile driving. After the GPS pile positioning meets the requirements, GPS will be the main method and conventional methods will be supplemented.
When positioning conventional pile sinking, one total station and two J2 theodolite are used for pile sinking control. The control method is the forward intersection method, in which the total station and one theodolite are used for positioning, and one theodolite is used for verification. To improve the accuracy of pile sinking, the front intersection angle is planned to be controlled between 60° and 120°. The penetration and pile top elevation during the pile sinking process is controlled by a level. After the stakeout data of each pile position is calculated by computer, some parts will be extracted for inspection. The results will be submitted to the supervision engineer for signature and approval before use.
GPS positioning is achieved using the “Offshore Piling GPS Positioning System”.
Before specific positioning, input the design center coordinates, elevation, plane twist angle, and other parameters of the desired positioning pile into the computer. During positioning, real-time pile position data and graphics can be displayed on the display screen, as well as the designed pile position and deviation. The piling ship commander directs the piling ship to position correctly according to the relevant information displayed and then lowers the piles and starts driving.
6. Stake insertion
The surveyor will review the position of the PHC pipe pile, and if the self-inspection meets the requirements (if it does not meet the requirements, lift the pile at the lifting point, turn off the pile driver, and reposition; if the pile position changes error is within the allowable range, fine-tune its position), please ask the supervision engineer for inspection. , after meeting the requirements, proceed to the next step and gradually sign the relevant forms.
7. Hammering pile sinking
Release the lifting point, slide the pile hammer along the pile frame, press the hammer to stabilize the pile, open the clutch, start the landing gear, and hammer to sink the pile. In the initial stage of pile sinking, the hammer should be hammered lightly to prevent the pile from slipping. After the penetration is normal, the impact energy can be gradually increased. During the pile sinking process, if abnormal penetration, sudden drop of pile body, excessive inclination, displacement, etc. occur, pile sinking should be stopped immediately and reported to the supervising engineer and design unit promptly. It is recommended to use a D100 hammer to open the third gear or D125 to open the second gear.
8. Stop the hammer
Strictly implement the hammer-stopping standards in the design technical standards. During the pile-sinking process, set an appropriate pile-sinking rate to prevent revetment instability, and strengthen observation. If abnormal conditions occur, contact the design unit promptly.
The PHC pipe pile driving and hammer-stopping standards for this project are:
① Pile sinking standards adopt elevation control and penetration check.
② The hammer can be stopped when the pile top elevation reaches the design elevation and the average penetration of the last 10 blows is within 5-10mm/blow.
③ When the pile top elevation is 1-3m higher than the design elevation, and the average penetration of the last 10 blows is less than 5mm/blow, continue hammering for 30 blows, and there is no tendency for the penetration to increase, then pile sinking can be stopped. When the pile top elevation is more than 3m higher than the design elevation and the penetration is small, contact the design.
3) During the pile sinking process, the pile driving rate should be strictly controlled to prevent underwater bank slope instability, and observation should be strengthened. When abnormal conditions occur during pile sinking, the owner, design, supervision, and construction units should jointly study and resolve them.
4) Pile sinking shall be recorded and the final penetration shall be measured by the requirements of the “Port Engineering Pile Foundation Specifications” (JTS167-4-2012) issued by the Ministry.
9. Clamping piles
The PHC pipe piles in this project have a certain degree of freedom after sinking. The project area is in unprotected waters and is greatly affected by waves and currents. Therefore, after the pile sinks, the foundation piles will be connected as a whole with a fence with greater stiffness in time. When clamping piles and fencing, choose weather with smaller wave heights and construct during flat tides.
10. Pile sinking testing requirements and quality standards
1. Testing requirements
After the pile is driven, the pile foundation shall be inspected promptly, focusing on high-strain and low-strain inspection. The specific requirements are as follows:
High strain detection frequency: 5 PHC piles are extracted from the approach bridge and wharf of this project (all need to be driven initially, three of them need to be driven again, and the interval between initial driving and repeated driving should not be less than 14D). All steel pipe piles at the wharf of this project are extracted 5 piles are subjected to high-strain dynamic testing (all require initial driving, three of which require re-driving, and the interval between initial driving and re-driving should not be less than 14D). High-strain testing should also be performed on piles with abnormalities during the driving process.
Frequency of low-strain testing: 25 piles were sampled from the approach bridges and 17 piles from the wharf in this project. Low-strain testing should also be carried out if there are abnormalities during the piling process.
The specific location for pile foundation inspection will be determined based on the actual pile driving conditions at the construction site in conjunction with relevant participating units, and representative locations and pile locations with abnormalities during the pile driving process will be selected.
11. Quality control measures
The project management department should adhere to the purpose of “quality first, credibility first, customer first”, establish and improve the quality management organization structure, implement the quality responsibility system, and strengthen supervision from all aspects of the organization, management, technology, materials, etc., and the entire construction process. Ensure that the pile foundation construction quality meets the technical standards specified in the design and specifications.
The main quality control measures are as follows:
1. Choose an excellent PHC pipe pile manufacturer, strengthen protection during lifting and transportation, and avoid damage to the pile body; do a good job of on-site inspection of the pile foundation, and strictly and carefully inspect the appearance quality of the pile before driving. If any If the pile body does not meet the requirements, it shall not be used to ensure the quality of the pile foundation from the source.
2. Make technical preparations carefully, be familiar with the design intention of the pile foundation of this project, make technical briefings to the piling ship and relevant construction workers before piling, and file them in writing.
3. There are a large number of foundation piles in this project. To ensure the construction quality, the pile positions will be reviewed one by one before pile sinking, and the sequence of pile sinking will be arranged reasonably. Pile position map, check whether there is pile collision, avoid pile collision and failure to drive, and ensure smooth pile sinking.
4. Due to the complex geological conditions of this project, the geological data cannot be completely consistent with the actual situation. A small amount of the geological data will inevitably be lower than the design elevation or higher than the design elevation. During the entire pile-sinking process, it is necessary to carefully explore the experience, analyze and compare the actual depth reached by the pile tip and geological data, to more scientifically determine the pile-sinking technical measures for the next structural section.
5. If it is discovered during construction that the geological data is significantly different from the actual situation, it will be reported to the supervision, design, and other relevant units as appropriate, and a certain amount of drilling data will be supplemented to ascertain the true situation and avoid leaving hidden dangers to the project.
6. For areas with gravel and sand layers and difficult pile sinking, appropriate countermeasures may be taken after discussing with the supervision engineer and designer depending on the specific circumstances.
7. Strengthen the maintenance of measuring instruments and ship machinery equipment. Testing must be carried out before pile sinking to eliminate human hazards.
8. The surveyor will mark the pile scale and calibrate the lifting position of the pile to ensure that the lifting point is accurate and meets the design requirements. Lifters should pay special attention when hoisting piles and pay attention to pile collisions. If a collision occurs, report it to the relevant personnel of the management department for inspection promptly. Only after the inspection is correct can they continue to be used.
9. Each time the piling boat deploys anchors, it must first conduct a test pull and confirm that it is reliable before use; during piling construction, all construction boats on site shall be coordinated and commanded by the construction crew and work closely together.
10. Before starting the hammering, check whether the hammer, replacement driver, and pile are on the same axis. During the hammer pressing process, adjust the verticality of the pile frame at any time to ensure that the pile hammer, replacement driver, and pile are on the same axis. The replacement driver should be kept flat. Avoid eccentric hammering.
11. If a large displacement of the pile occurs during the pile setting process, the pile must be lifted and re-installed; during the pile sinking process, an appropriate amount of advance shall be taken according to the rules of pile trial sinking to ensure the correct positioning rate of the pile.
12. During the pile sinking process, try to hammer the pile lightly. It is strictly forbidden to pull the pile to correct the deviation during the pile sinking process.
13. When driving piles in advance, use neutral gear for trial driving. After confirming that pile slipping will not occur, use normal gear for driving. The operation of the piling boat shall be carried out strictly according to the requirements to prevent improper operation such as anchor slipping and insufficient anchor force. etc. causing quality accidents.
14. If any abnormality occurs during the hammering process (abnormal penetration, large rebound after removing the cap, sudden anchor failure during hammering), please contact the supervision, design, and other relevant departments promptly to negotiate a solution.
15. Strengthen the contact between ship operators and surveyors to ensure good communication during pile sinking construction.
16. After the piles have been sunk, barriers should be installed in time to reinforce the pile tops to reduce the additional bending moment of the pile body and enhance the pile’s ability to resist damage from external forces. A warning vessel should be set up to ensure the safety of the completed pile foundation.
17. When sinking piles, keep records of pile sinking, fill them in carefully according to the specifications, and keep the pile sinking information properly.
12. Safety and environmental protection control measures
The project management department should adhere to the principle of “safety first, prevention first, comprehensive management” and the purpose of protecting and improving the environment, protecting sea resources, preventing construction from causing pollution and damage to the environment, maintaining ecological balance, and protecting human health, and establish and improve safety, The environmental protection management organization shall implement the safety responsibility system, strengthen management ideologically, organizationally, institutionally, technically, and at work, take necessary measures to prevent problems before they occur and strengthen supervision throughout the construction process to ensure the safety of pile foundation construction. , to meet environmental protection requirements. The project management department held a technical seminar on pile driving safety and environmental protection, assessed foreseeable or possible risks during the pile driving operation, and proposed safety and environmental protection control measures.
(1) Safety control measures for ships, machinery, and personnel
1. Obtain water construction permits and navigation notices before construction, and demarcate the construction area. Navigation signs such as navigation buoys and guidance lights should be set up according to the requirements of the navigation department. Construction vessels should hang avoidance signals and flags, and send special personnel to guard them. Lookouts should be strengthened during construction, and signal lights should be set up by regulations at night.
2. All ships participating in the construction must have complete “three certificates” and be equipped with life-saving facilities and equipment such as life-saving poles, inflatable life rafts, and life buoys with ropes. The piling ship is equipped with a lifeboat. To ensure that the safety facilities of the ships entering the site are suitable, the project management department conducts careful safety inspections on each ship, and if any hidden dangers are found, the person, measures, and time will be identified for rectification.
3. The person in charge of on-site construction safety and technology shall conduct level 3 safety education and safety technical explanations to the workers participating in the construction in the form of conference lectures and shall keep records and sign for confirmation.
4. Workers should correctly wear safety helmets, life jackets, safety belts, safety ropes, and other corresponding personal protective equipment and take safety protection measures. Safety helmets, seat belts, and safety nets are inspected regularly and products that do not meet safety standards are replaced.
5. Carry out team activities and conduct targeted safety briefings for workers every day. Machinery, tools, and instruments must be inspected before work and must be confirmed to be in good condition before use. Any rectifications discovered during safety inspections conducted by superior departments or teams themselves are recorded in writing, and the person responsible for the rectifications is assigned to the person responsible for the rectifications.
6. Personnel with special types of work must hold valid certificates to work. Unlicensed personnel are strictly prohibited from operating or repairing machinery and electrical equipment.
7. Establish a weather forecast receiving system: In the event of severe weather, construction must be stopped, and all ships and equipment must be safely protected.
(2) Safety control measures for pile transport operations
1. The tugboat can only be towed after passing the security inspection of the ship inspection department and completing relevant towing procedures;
2. Conduct safety inspections on pile-carrying barges, requiring all safety and emergency facilities to be complete and effective. The length, width, and load-tonnage of pile-carrying barges must meet the pile-carrying requirements, and the number and method of pile-carrying barges must meet the ship’s carrying capacity and stability requirements;
3. When loading foundation piles, the cable crane and anchor system must not be pressed;
4. When the length of the foundation pile exceeds the pile-carrying barge, it should be stored in a staggered manner, and no unbalanced or overloading is allowed;
5. Carry out necessary inspections on the pile-carrying barge during the process of loading foundation piles. If it is found that the baffles on both sides are broken or tilted due to unbalanced loading, the loading operation should be stopped immediately and reinforced immediately:
6. After the foundation piles are hoisted, use 8 polyester ropes to seal the pipe piles. After thorough inspection and confirmation of safety, they can be shipped:
7. The tugboat must lean lightly when assisting, and the cable must be firmly tied. Violent collisions are prohibited:
8. When encountering large waves, rapids, etc. during transportation, making it difficult for the tug to tow, or due to emergencies such as tow cable breakage or tug failure, the personnel on duty on the pile transport barge should immediately anchor and report the situation to the project management department and wait for rescue;
9. No open flames are allowed without permission during pile transportation:
10. When entering the construction site, the tugboat slows down and sails. After the PHC pipe piles are transported into place, they are immediately tied to the positioning ship. When anchoring, the anchor rope avoids entanglement or collision with the piling ship.
(3) Safety control measures during pile lifting and sinking processes
1. Before lifting, carefully check the lifting system and the attached spreaders to make sure there are no faults or unsafe factors before proceeding with the hoisting operation:
2. When lifting the pile, first lift the pile as a whole away from the barge and then pause for a few minutes before conducting a second inspection. If any abnormality such as broken wires in the hanging rope, abnormal noise in the pulley, tilting or shifting of the piling ship, or deformation of the hanger is found, When lifting, first gently lower the PHC pipe pile, rectify the existing hidden dangers or reposition the piling boat. After the rectification is completed, repeat the above lifting procedure, and then raise the PHC pipe pile after confirming safety;
3. When there is wind influence, set up traction ropes at both ends of the PHC pipe pile in advance. When the pile swings and twists, use the ropes to control the direction to prevent the PHC pipe pile from colliding with the hanger:
4. When the pile rotates vertically, the auxiliary hook must be lowered slowly;
5. During the pile lifting process, all personnel are evacuated to a safe area, and no one is allowed to stand on or above the PHC pipe pile;
6. Personnel who mount the pile frame for inspection or maintenance must wear seat belts and are prohibited from leaning out of the cage:
7. When positioning the piling ship, check the anchoring condition of the anchor cable, start the windlass at a slow speed, and brake in time if any abnormality in the anchor cable is found. If the piling ship continues to shift due to inertia after braking, the high-horsepower duty tugboat will push it in time. , to prevent the cable from breaking and causing the anchoring accident of the piling ship:
8. When sinking piles, make sure all preparations are completed and check that no one is on or around the pile frame before starting the pile sinking hammer:
9. During the pile-driving construction process, the command must be unified, and each key position shall be responsible for its responsibilities. Illegal operations and drunken operations are prohibited. Pile sinking operations shall be stopped when the wind reaches level 6;
10. Unrelated personnel are prohibited from entering the work site;
11. After the pile sinking is completed or completed on the same day, navigation lights and eye-catching flags should be set on the PHC pipe piles that have been driven.
(4) Environmental protection control measures
1. All ships participating in water construction are not allowed to throw production and domestic garbage into the sea at will. The garbage is stored in a centralized manner and sent to the area designated by the maritime department by a dedicated garbage transport ship.
2. All construction ships are not allowed to discharge oil pollution and sewage into the sea at will. Oil pollution and sewage should be pumped to special sewage transport ships and handed over to the maritime department for unified treatment.
13. Emergency response measures for ship emergencies
1. Measures to deal with people falling into the water or groups falling into the water and drowning due to strange and strong winds
(1) When it is discovered that someone has fallen into the sea (falling into the water), the captain immediately sounds the (person falling into the water) alarm: three long beeps for one minute or broadcast a rescue signal. At the same time, other personnel will throw a lifebuoy, a lifeline, or a lifeline hook to assist in self-rescue.
(2) Select crew members or other emergency personnel who are familiar with the water to go into the water immediately for rescue. After entering the water, swim to the back of the victim, hold his armpits with your hands, let him face up, and lift him to the shore with his nose out of the water.
(3) Immediately use the high-frequency intercom to call the on-site traffic ship, and the emergency rescue ship on duty will come to the rescue.
(4) If the drowning person stops breathing, stand upside down to drain the water, and perform artificial respiration and chest compression at the same time for rescue. The two operations can be alternated with each other. At the same time, do a good job of keeping warm.
(5) Request the hospital rescue team to come to the scene for rescue and send the drowning person to the hospital for treatment.
2. Measures to prevent ships from capsizing and sinking due to sudden monsoon winds, strange winds, and rough waves
(1) When severe weather such as cold waves, gusty winds, thunder gusts, and violent waves is forecast, the Safety Department will send messages via text message to the captain of each ship and to each person responsible for wind, typhoon, and wave prevention to prevent wind and waves. measures work.
(2) When a wind forecast of level ≥6 is received or the maritime department issues a strong wind warning, water construction vessels and personnel 7 should be prepared for wind protection. Six hours before the strong wind arrived, all ships, construction equipment, and personnel stopped operations and began to take shelter from the wind.
(3) After the emergency command center issues wind protection and shelter instructions, all construction equipment should be reinforced and parked properly, and construction workers should withdraw to the land.
(4) Winds above level 10 will be handled according to the typhoon prevention plan.
(5) Construction workers, safety officers, technicians, and dispatchers at the construction site suddenly discover sudden changes in cloudy weather, and immediately use high-frequency telephone calls to notify all parties to prepare for lightning and wind gusts.
(6) In the event of a sudden gust of wind, strange winds, and rough waves, the large ship should pull up the anchor and evacuate to the deep water area to anchor, and loosen the cable for at least 300 meters. If there is no time to evacuate, loosen the long cable in place and adjust the ship’s position to withstand the wind and waves. Otherwise, the engine will bear the wind. Resist waves.
(7) Small ships cannot evacuate in time to take shelter from the wind, so they can temporarily take shelter behind large ships.
(8) After receiving the distress signal, the rescue plan is initiated according to the procedure. The rescue team rushes to the scene of the disaster and first takes all personnel to the rescue boat and transfers to land.
(9) If the rescue capability exceeds the self-rescue capability, you should call the Maritime Search and Rescue Center for help. The contact number is 12395.
(10) Report the danger of distress to the maritime affairs department and relevant departments. After the personnel are safely transferred, an abandon ship plan can be adopted.
3. Emergency measures for lifting and object impact
(1) After an accident occurs, the first discoverer or the person in charge of on-site construction shall immediately report to the emergency rescue command center, briefly describing the time, location, accident situation, number of injuries, and severity of injuries, etc.
(2) The commander makes a decision based on the situation: rush to the scene of the incident immediately and organize rescue according to the injuries of the personnel;
(3) Immediately contact the emergency center or hospital, report the location of the accident, the number of injured people and their condition, and ask them to dispatch emergency personnel and vehicles; the contact number of the emergency center is “120”.
(4) Immediately organize personnel, ships, and vehicles to rush to the scene, provide simple first aid to the injured, and wait for the arrival of emergency personnel from the emergency center or hospital.
(5) Simple first aid: If the wounded person’s wound bleeds heavily, tie the local arteries and blood vessels with a bandage or torn clothes, and use a stretcher to move the injured person to a quiet place; for fracture wounds, cloth bandages, and wooden splints can be used to temporarily fix the injured part without damaging the local nerves. , pay attention to keeping warm; in case of shock, artificial respiration or external heart compression methods should be performed immediately.
(6) Immediately send the injured to the hospital for first aid.
(7) Ambulance vehicle guide: medical security team.
4. Emergency measures for electric shock
(1) In the event of an electric shock accident, first try to remove the electric shock victim from the power supply as soon as possible. If it is a low-voltage (220-380V) power grid, immediately turn on the nearby power switch or pull out the plug. If necessary, use a sharp ax or hoe with an insulated handle to cut off and dry the power supply. Use wooden sticks or materials with good insulation to pry open the power cord.
(2) In case of high-voltage electric shock, immediately notify the power department to cut off the power. Rescuers are not allowed to have direct contact with electricity and are not allowed to use metal or rescue tools with poor insulation.
(3) The rescuer should use one hand to pull or pry the person who received an electric shock, which is safer. Two-hand operation is strictly prohibited.
(4) When the person who gets an electric shock is in a high place, take preventive measures to prevent the person who gets an electric shock from falling to the ground to death or being injured after being disconnected from the power source.
(5) When an electric shock accident occurs at night, temporary lighting after cutting off the power supply should be considered to facilitate rescue.
(6) Rescue method: The person who was electrocuted was unconscious for a while, and he was sent to the hospital immediately if he regained consciousness; if the injury was serious and he lost consciousness, immediately hear the beating of the heart and no breathing, use “artificial respiration” and external heart compression at the same time. save. At the same time, he was sent to the hospital while receiving first aid.
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