Construction control of the hottest bored belled p

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Construction control of bored belled pile

1. Hole formation

hole formation is mainly the process of drilling to the design elevation with a double belt cage drill. During the hole forming process, all metal components will be damaged, mainly controlling the verticality of the hole, the integrity of the retaining wall, and the determination of the rock surface of the bearing layer. Hole forming is the foundation of hole enlarging

2. Reaming

before reaming, first determine the required parameters of the reamed pile head on the ground, and then use it. After the hole reaches the design elevation, lift the drill bit, replace the reaming drill bit, connect the drill bit through the drill pipe, place it at the bottom of the hole, mark the position before reaming and the displacement value required for reaming on the main drill pipe, and then move the drill tool up and lift it, drill and start reaming. In the process of reaming, the control of reaming bottom mainly controls the rotation speed, stroke and the firmness of drilling tools. ROP control mainly controls the speed of the drill. As the cutting surface of the reaming bit increases with the expansion of the bit, its action load also increases. In order to ensure that the bit does not deform, it is required to drill at a constant speed and gradually put down the drill pipe, so as to ensure that the packing box is opened in more ways and more convenient for operation, and the drilling displacement is stable, so as to achieve the effect of reaming. Stroke control is to control the slide way of drill spindle to achieve the purpose of reaming. Therefore, different reaming pile diameters, different bits used, and their displacement values are also different. Therefore, during the reaming process, the stroke value must be strictly recorded to ensure that the reaming meets the design requirements. The control of drilling tools is the stability control of the drill bit, that is, to ensure the stability and firmness of the drill bit in the drilling process. Before reaming, the drilling tool should be inspected first. The rigidity of the upper and lower wing cutters should be hinged firmly, and the spindle slideway should be retracted and retracted flexibly. It can be used only after ensuring its good performance

3. Hole cleaning

because the area of the pile bottom increases greatly after the pile diameter is enlarged, forming the lower hole cave. During hole cleaning, the hole cave is prone to a large amount of sediment deposition. Therefore, whether the hole is cleaned thoroughly directly affects the effect of pile forming. In the process of hole cleaning, reverse circulation shall be used to clean the hole, and the sediment at the pile bottom shall be sucked out of the hole to achieve the purpose of hole cleaning

make it coincide with the main needle

4. Pile forming

after drilling and reaming, empty soil and ponding at the bottom of the hole should be removed. When pouring concrete, the depth of ponding in the middle of the hole bottom should not be greater than 10mm, and then pour concrete as soon as possible. Pour concrete to about half the height of the enlarged head, that is, place reinforcement cage, continue to pour concrete, vibrate and compact in layers, and the slump of concrete can be 4 ~ 6mm or 6 ~ 8mm depending on the water content of the soil

due to the increase in the volume of the bottom of the bored pile, during the concrete pouring process, ensure that the buried depth of the tremie after the flushing will not affect the quality of the pouring. Therefore, during ball flushing, the storage material must meet the requirements that the buried depth of the conduit after ball flushing is greater than 1.5m. In the process of pile forming, the concrete pouring must ensure its continuity and the total volume of concrete

5. Pile forming inspection

in the process of pile foundation construction of the project, through the construction control of the above links, how will the power battery enterprise continue to complete the construction of the whole project pile? After the joint construction of large enterprises, the piles were tested by ultrasonic transmission method, low strain reflection wave method and drilling core pulling method according to relevant regulations. The core pulling method showed that the sediment thickness of the tested piles met the design requirements, indicating that the reverse circulation method was successful in hole cleaning. At the same time, two piles with diameters of? 1600、? 1800 pile to test the effect of its enlarged head. The method is: take the pile center as the center, move the edge of the enlarged head diameter (2900mm and 3100mm respectively) to the direction of the pile center s (s = pile length L 0.5%), arrange points in four directions, drill down, and extract core samples, proving that the enlarged head construction has achieved the design goal

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