The existing technology in the manufacturing process, mostly manual semi-automatic CO2 gas shielded welding for welding, the problem is that the shape of the blade attached to the SSAW pipe pile and the pitch control is quite difficult, according to the pitch button button welding in turn, while welding side adjustment, resulting in spiral blade pitch is not equal, the blade shape is not regular, welding stress distribution is not uniform, and it is difficult to avoid the cumulative error generated by the pitch, directly affecting the product The appearance of the product into shape and the internal quality.
Here is the content list:
The installation of SSAW pipe piles should meet the design requirements
SSAW pipe pile requirements in transportation and stacking
What are the considerations for installing SSAW pipe piles?
The material for making SSAW pipe pile should meet the design requirements, and have factory certificate and test report, and the site should have a flat site and wind and rainproof facilities. SSAW pipe piles used in erosive groundwater areas or corrosive soils shall be treated with anti-corrosion treatment according to the design requirements.
Floating rust, oil and other dirt on the end must be removed and kept dry.
The deformed part of the top of the lower section SSAW pipe pile after hammering shall be cut off.
The verticality shall be corrected when welding the upper and lower sections of SSAW pipe piles, with a gap of 2-3mm at the counterpart.
The welding wire (automatic welding) or welding rod shall be dried.
Welding shall be carried out symmetrically.
Welding shall be applied in multiple layers, the joints of the layers of SSAW pipe piles shall be staggered and the welding slag shall be removed.
No welding shall be done when the temperature is below 0°C or in rain or snow without reliable measures to ensure the quality of welding.
Each joint should be cooled for one minute before hammering; welding quality should be in accordance with the National Code of Construction and Acceptance of Steel Structures and the Building Steel Welding Regulations, each joint should be inspected in addition to the appearance in accordance with Table 7.6.1, but also 5% of the total number of joints to do ultrasound or 2% to do X-rays, in the same project, flaw inspection shall not be less than three joints. SSAW pipe pile or other shaped thin-walled steel piles If there is no provision for the type of joint, it can be set according to the same strength; transportation and storage of SSAW pipe pile.
SSAW pipe pile should be transported and stacked with the following points in mind: the stacking site should be flat, solid and well drained; the ends of the SSAW pipe piles should be properly protected, and SSAW pipe piles should be set up with a protective ring; the SSAW pipe piles should be prevented from being damaged or bent due to impact; SSAW pipe piles should be stacked according to specifications and materials, and the number of layers should not be too high; for steel piles, φ900 diameter is placed in three layers; φ600 is placed in four layers; φ400 is placed in five layers; for steel sections, φ900 diameter is placed in three layers; φ600 is placed in four layers; and φ400 is placed in five layers. 400 is placed in five layers; for steel piles, up to six layers; pivot points should be set reasonably, and both sides of SSAW pipe piles should be plugged with wooden wedges to prevent rolling.
When it is necessary to cross old clay, thick layer of sand, gravel soil and clay with plasticity index more than 25, test drilling should be carried out. After the drilling rig is positioned, it should be rechecked, and the deviation between the drilling head and the pile position point should not be greater than 20㎜; the down drilling speed should be slow when opening the hole; during the drilling process, it is not appropriate to reverse or raise the drilling rod. In the process of drilling, when the drill is stuck, the rig is shaking, skewed or abnormal sound occurs, the drilling should be stopped immediately to find out the reason and take corresponding measures before continuing the operation.
SSAW pipe pile is assembled and welded by a tubular mandrel and a spiral blade wound on the mandrel, and the blade is required to be spirally attached to the steel pipe and welded according to a certain pitch.
When drilling in the sandy soil below the water table, there should be measures to prevent water ingress at the bottom flap of the SSAW pipe pile, and the pressurized concrete filling should be carried out continuously. The filling factor of the pile should be 1.0~1.2, and the height of concrete overfilling should not be less than 0.3~0.5m.
After the SSAW pipe pile is completed, the residual concrete in the drill pipe and pump pipe should be removed in time. When the pile is parked for a long time, the drill pipe, pump pipe and concrete pump should be cleaned with water. After the concrete pressure filling is finished, the reinforcement cage should be inserted to the design depth immediately. It is appropriate to use special inserter for inserting reinforcement cage.
