When the drill bit approaches the bottom edge of the casing, slow down and lift it stably to prevent collision with the casing and hook the bottom edge of the casing.
The joints must be bound firmly to ensure that they are impervious to water and electricity.
The mud is recycled after sedimentation.
Reverse circulation: mud flows naturally from the outside of the pipeline or pumped into the hole, and then is pumped to the ground together with soil slag.
8.
3.
The moderately weathered argillaceous siltstone is the bearing capacity, and the thickness of the protective layer of the pile body concrete shall be ≥ 50mm.
3、 Technological process of reverse circulation bored cast-in-place pile (I) setting out of pile position IV.
4.1 the concrete strength grade of cast-in-place pile of the project is ﹐ C35 ﹐ underwater concrete Slump 180-220mm 6.
key points of quality control (I) pile position control (II) pile perpendicularity control (III) pile length control (IV) pile rock penetration depth control (V) sediment thickness control at pile bottom (VI) pile body integrity control (VII) pile top elevation control (VIII) quality requirements v Key points of safety control (I) mud pit protection 1.
After the drilling machinery is in place, the drilling rig and supporting equipment shall be comprehensively inspected.
Under the suction of the vacuum pump, the mixture enters the slag inlet of the drill bit and is discharged into the sediment pit through the inner cavity of the drill pipe and the slurry outlet control valve.
When moving the drilling rig, the cables shall not be squeezed.
4.
6.
4.
After hole cleaning, the sediment thickness shall not be greater than 50mm, and underwater concrete shall be poured immediately.
according to the drawings, as shown in the following figure.
2.
Identify the rock sample and confirm whether it enters the rock, ends the hole and whether there is interlayer.
In case of power failure or other special circumstances during operation, the heavy objects shall be dropped to the ground and shall not be suspended in the air.
2、 Reverse circulation equipment: reverse circulation process principle: the mud flows into the borehole from the mud pit and is mixed with the drilling slag.
The quality safety department shall cooperate with the electrician to regularly check the cables used by the drilling rig.
Quantity (1) 337 supporting piles, (2) engineering piles: 101 piles for 1 # building, 86 piles for 2 # building, 91 piles for 3 # building, 79 piles for 4 # building, 126 piles for 5 # building, 10 piles for 6 # building, 216 piles for 2 # building and 711 piles for basement.
2.
4.
Confirm the placement of machine position and piling sequence, and deal with emergencies.
Special personnel shall be assigned for unified command of hoisting operation.
The pile end of compression pile shall enter the bearing stratum not less than 1D, and the pile end of uplift pile shall enter the bearing stratum not less than 2D.
Rig installation must be stable and firm; The drill frame shall be erected with diagonal bracing or wind rope.
1、 Project overview the main technical indicators of the project 1.
7.
Safety training and technical disclosure shall be conducted for construction technicians and construction personnel before construction.
3.
If the embedded pile casing has not been drilled or the pile casing has not been pulled out, the top cover of the pile casing shall be added or the safety net shall be laid.
Before hoisting, strictly check the reliability and safety of all components of hoisting equipment.
Identify the pile position and determine the pile number of the newly opened hole according to the released pile position and the laid steel rail.
5.
(jump the pile driving position, analyze the situation after the concrete pouring fails, etc.).
The lifting workers participating in hoisting shall master the operation safety requirements, and other personnel shall have a clear division of labor.
The design grade of the foundation of the project is Grade A.
6、 Work contents of pile foundation constructors 1.
Determine the pile diameter, pile top elevation, rail surface elevation, hanging reinforcement length, empty pouring height, etc.
2.
After the pile body is drilled into the bedrock, the hole shall be cleaned and sampled every 500mm; Analysis and sampling preparation for final hole acceptance.
After the pile hole is formed, the sediment at the hole bottom must be removed.
5.
3.
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