After the deep foundation pit is backfilled, the steel sheet pile shall be removed to facilitate repeated use. Before pulling out the steel sheet pile, the sequence of pulling out methods, pile pulling conditions and soil holes should be studied carefully and scientifically. Because of the vibration hazard of pulling out piles, and too many pile pulling cards will cause ground collapse and movement, which will cause damage to the underground structure of the project, and endanger the safety of neighboring original buildings, buildings or underground pipelines. Pulling out the pile card is very important. At this stage, the key is to choose water injection and sand injection countermeasures.
What should I pay attention to when pulling out steel sheet piles?
1. Pulling pile method: Use vibration hammer to pull the pile, use the forced vibration caused by the vibration hammer to oscillate the soil layer, destroy the cohesive force of the ground around the steel sheet pile to get rid of the pile pull resistance, and pull it out with the help of additional lifting force.
2. Common problems when pulling piles
a. Starting point and sequence of pulling out piles: For closed steel sheet pile walls, the starting point for pulling out piles should be 5 above the corner piles. The starting point of the pile extraction can be determined according to the situation when the pile is sinking, and the method of jumping and pulling can also be used when necessary. The sequence of pulling piles is best to be reversed when the foundation piles.
b. Vibrating and vibrating: When pulling out the pile, first use a vibrating hammer to vibrate the sheet pile lock to reduce soil adhesion, and then pull out while vibrating. For sheet piles that are more difficult to remove, first use a diesel hammer to vibrate the pile down by 100 to 300 mm, and then replace it with a vibrating hammer for vibrating and vibrating.
c. The lifting equipment should be slowly loaded with the operation of the vibrating hammer, and the lifting force is generally slightly lower than the shrinkage limit of the shock absorber spring.
3. If the steel sheet pile cannot be pulled out, the following countermeasures can be used:
a. Hit it again with a vibrating hammer to get rid of the resistance caused by adhesion to the ground and the rust between the bite;
b. Pull out piles in the reverse order of the supporting order of sheet piles;
c. The soil on the side of the sheet pile that bears the soil pressure is relatively dense, and another sheet pile is driven side by side around it to pull out the original sheet pile smoothly;
d. Drill grooves on both sides of the sheet pile and put in the bentonite slurry to reduce the resistance when pulling out the pile.
4. Common problems and solutions on steel sheet pile construction sites:
a. Skewed. The reason for this type of problem is that the resistance between the foundation piling and the lock of the adjacent pile is very large, and the penetration resistance of the driving direction of the foundation piling is small;
b.The solutions are as follows: the whole process of engineering construction selects instruments and equipment to inspect, manipulate, and correct anytime and anywhere; when skew occurs, the galvanized steel wire rope must pull the pile body, pull it while driving, and gradually correct it; first use floor piles to properly embed the error.
c. Distortion. The reason for this problem: the lock is hinged connection;
The solutions are as follows: lock the front locking of the sheet pile with a wooden pallet in the driving position of the foundation pile; in the gap between the two sides of the sheet pile, set a movable pulley support frame to discourage the rotation of the sheet pile when it moves down; on the two sheet piles Fill both sides of the buckle with pads and dowels.
Note:The steel pipe pile is composed of steel pipe, tongue-and-groove and tongue-and-groove pins. The pipe wall at the left end of the diameter of the steel pipe is vertically connected with the tongue-and-groove. The cross-section of the groove is a box shape with one side open. Reinforcing ribs are arranged on the side of the groove, and a tongue-and-groove pin is vertically connected on the pipe wall of the right end of the diameter of the steel pipe and the position of the radius, and the groove section of the tongue-and-groove pin is an I-shaped.
What should I pay attention to when pulling out steel sheet piles?
1. Pulling pile method: Use vibration hammer to pull the pile, use the forced vibration caused by the vibration hammer to oscillate the soil layer, destroy the cohesive force of the ground around the steel sheet pile to get rid of the pile pull resistance, and pull it out with the help of additional lifting force.
2. Common problems when pulling piles
a. Starting point and sequence of pulling out piles: For closed steel sheet pile walls, the starting point for pulling out piles should be 5 above the corner piles. The starting point of the pile extraction can be determined according to the situation when the pile is sinking, and the method of jumping and pulling can also be used when necessary. The sequence of pulling piles is best to be reversed when the foundation piles.
b. Vibrating and vibrating: When pulling out the pile, first use a vibrating hammer to vibrate the sheet pile lock to reduce soil adhesion, and then pull out while vibrating. For sheet piles that are more difficult to remove, first use a diesel hammer to vibrate the pile down by 100 to 300 mm, and then replace it with a vibrating hammer for vibrating and vibrating.
c. The lifting equipment should be slowly loaded with the operation of the vibrating hammer, and the lifting force is generally slightly lower than the shrinkage limit of the shock absorber spring.
3. If the steel sheet pile cannot be pulled out, the following countermeasures can be used:
a. Hit it again with a vibrating hammer to get rid of the resistance caused by adhesion to the ground and the rust between the bite;
b. Pull out piles in the reverse order of the supporting order of sheet piles;
c. The soil on the side of the sheet pile that bears the soil pressure is relatively dense, and another sheet pile is driven side by side around it to pull out the original sheet pile smoothly;
d. Drill grooves on both sides of the sheet pile and put in the bentonite slurry to reduce the resistance when pulling out the pile.
4. Common problems and solutions on steel sheet pile construction sites:
a. Skewed. The reason for this type of problem is that the resistance between the foundation piling and the lock of the adjacent pile is very large, and the penetration resistance of the driving direction of the foundation piling is small;
b.The solutions are as follows: the whole process of engineering construction selects instruments and equipment to inspect, manipulate, and correct anytime and anywhere; when skew occurs, the galvanized steel wire rope must pull the pile body, pull it while driving, and gradually correct it; first use floor piles to properly embed the error.
c. Distortion. The reason for this problem: the lock is hinged connection;
The solutions are as follows: lock the front locking of the sheet pile with a wooden pallet in the driving position of the foundation pile; in the gap between the two sides of the sheet pile, set a movable pulley support frame to discourage the rotation of the sheet pile when it moves down; on the two sheet piles Fill both sides of the buckle with pads and dowels.
Note:The steel pipe pile is composed of steel pipe, tongue-and-groove and tongue-and-groove pins. The pipe wall at the left end of the diameter of the steel pipe is vertically connected with the tongue-and-groove. The cross-section of the groove is a box shape with one side open. Reinforcing ribs are arranged on the side of the groove, and a tongue-and-groove pin is vertically connected on the pipe wall of the right end of the diameter of the steel pipe and the position of the radius, and the groove section of the tongue-and-groove pin is an I-shaped.
