1. Arrangement and spacing of tamping points: the main tamping points shall be arranged in a square with a spacing of 4m, and the auxiliary tamping points shall be interspersed in the middle of the main tamping points with a spacing of 4m. The full tamping points shall be overlapped with each other for 1 / 4 continuous tamping. The setting out of tamping points is marked with lime piles. The ground elevation is measured before and after each tamping, and the tamping settlement is calculated.
2. The rammer is in place for main ramming: the rammer adopts cylindrical hammer with diameter of 2.5m, height of 1.2m, bottom area of 4.91m2 and weight of 16.12t. This hammer is used for main, auxiliary and full rammers. The impact distance is 13.5m and the impact energy is 2133kn · M.
After the rammer is in place, the rammer shall be lifted to the predetermined height according to the designed ramming energy, and the hook shall be lowered to measure the inclination of the bottom of the rammer. When the inclination is greater than 30 degrees, the tamping pit shall be filled before ramming. Main ramming, 4 hammers per point. According to the above spacing, square layout. And make detailed records.
3. Move to the next point. Until one tamping is completed. After the completion of the main tamping, it shall be allowed to stand for one week. After the pore water pressure disappears, the tamping pit shall be leveled and the auxiliary tamping shall be prepared. Measure and position again, and carry out the construction of auxiliary rammer according to the above points.