Because the pipe pile is round, the soil squeezing effect is greater than that of the sheet pile, and there are more process procedures, and the steel sheet pile can be directly driven in and connected. The advantage is that compared with other steel piles, steel pipe columns have their own unique advantages in many aspects, such as extension welding, single pile bearing capacity, bending rigidity, penetration ability and many other aspects.
a. Transportation and stacking of steel pipe piles
Steel pipe piles can be stacked in multiple layers according to the pile sinking sequence during transportation. Each layer of skid is located on the same vertical surface. The number of stacked pipe piles on the ship cannot easily exceed three to ensure the safety of the ship. During the lifting, transportation and storage of steel pipe piles, damage to the pipe body due to collisions and other reasons must be avoided. Note that the pipe joint welds should be checked again before the steel pipe pile is settled.
b. Settling of steel pipe piles
Calculate the coordinates of each steel pipe pile before sinking, and arrange a baseline for each pile on the levee on both sides of the bank. Use a total station to accurately measure the coordinate position of each observation point on the baseline, and measure its elevation with a level. ; Then calculate the coordinates and intersection angle of the observation point on each pile, and summarize them into a table for observation of pile sinking. When sinking, a total station is arranged on the front for observation and positioning, and two theodolites on the side for verification.
Pay attention to the settlement of steel pipe piles: the center of the vibrating hammer and the center axis of the pile should be kept in the same straight line as much as possible; the sinking of each pile should be continuous, and it should not be paused for too long in the middle, so as to prevent the friction of the soil from recovering and it is difficult to continue sinking . Strengthen observation during the sinking process, the deviation of the steel pipe pile shall not be greater than 10 cm, and the verticality shall not be less than 0.1%.
c. Steel platform erection
After the steel pipe piles are settled, the drilling platform section steel layout is started. The specific steps are as follows:
The steel pipe piles are opened in the appropriate position along the water flow, the steel pipe pile heads are cut flat to install the spliced I45 I-steel beams, and the steel pipe piles (opening) walls are spot welded → C15 concrete is poured on the steel pipe pile heads to make I45 beams are embedded in the pile head → I36 I-beam distribution longitudinal beams are installed and welded with I45 beams (with stiffening plates) → δ=10mm thick steel plates are laid on the "well" beams, and safety railings are added.
At the beginning of the construction of the platform, navigation beacons were set up, navigational guidance signs such as night red light warnings were hung, and steel pipe pile anti-collision piers were erected.