Views: 0 Author: Site Editor Publish Time: 2026-11-09 Origin: Site
After the rotary drilling rig arrives on site, it moves to the pile position via the crawler chassis. The machine is leveled and outriggers are extended to stabilize the whole unit and avoid tilting during operation. The operator adjusts the drill mast angle through the luffing mechanism to align the center of the drill bucket precisely with the preset pile center. This step lays the foundation for hole quality, and alignment accuracy directly affects the verticality of the subsequent pile foundation, serving as the primary control point for pile construction on site.
Once aligned, the drill pipe is lowered to let the drill bucket touch the stratum. The bucket teeth cut rock and soil driven by torque from the power head. As the drill bucket rotates, soil is loaded into the bucket, and the bottom gate closes to contain the muck. When the bucket is full, the power head stops rotating. The main winch lifts the drill pipe and brings the bucket out of the hole. The rig slews to the dumping area, the bucket gate opens for muck discharge, then the rig slews back and lowers the bucket to resume drilling. The cycle repeats to deepen the hole gradually.
Slurry wall protection is adopted for sandy soil, silt and water-rich strata. Slurry forms a filter cake on the hole wall to balance hydrostatic pressure and prevent collapse. Operators monitor slurry parameters continuously and adjust slurry density and viscosity according to stratum changes. Cooperating with rotary excavation, slurry makes up for the weakness of rotary rigs in collapse-prone strata, keeping the hole wall intact and avoiding common defects such as hole collapse and necking.
Drilling stops once the designed pile depth is reached, and final hole acceptance starts. Workers use sounding lines and hole gauges to check actual hole depth, diameter and verticality. The hole is accepted only when all indicators meet drawing and specification requirements. If insufficient diameter or excessive sediment at the hole bottom is found, the drill bucket will be lowered again for bottom cleaning.
Qualified inspection marks the completion of hole forming. The finished borehole is ready for reinforcement cage lowering and concrete pouring to form the pile foundation. With cyclic cutting and bucket discharging, rotary drilling features faster penetration and lower noise than traditional percussion drills. It is widely used in pile projects for buildings, bridges and municipal works.
