Construction Methods of Rotary Drilling under Different Stratum Conditions

Rotary drilling RIGS, as the "steel earthworms" of modern engineering construction, are widely used in bridge and building pile foundation construction due to their advantages such as high efficiency and environmental friendliness. However, in the face of complex and changeable strata, construction methods need to be "adapted to local conditions". Next, we will analyze the key construction points of rotary drilling under different stratum conditions for everyone.

1. Clay and silty clay strata: Clay has high viscosity and is prone to clogging. During construction, the drilling speed should be reduced, short helical drill bits should be selected, and the clay in the drill bucket should be cleaned in time to avoid affecting the drilling efficiency due to the accumulation of drill cuttings.

2. Sandy soil strata: Sandy soil has poor stability and is prone to hole collapse. High-quality mud wall protection should be prepared in advance. Rotary bucket drilling should be adopted, and the drilling speed should be controlled to prevent the collapse of the hole wall and ensure the quality of the hole formation.

3. Gravel and pebble strata: These strata have large particles and high hardness. High-torque rotary drilling RIGS should be equipped, and toothed cylinder drill bits should be used for layer-by-layer drilling. When encountering large isolated rocks, impact drills can be used to break them before continuing the construction.

4. Rock strata: The rock strata are hard and difficult to drill. Select the appropriate drill bit based on the hardness of the rock, such as a hard rock toothed drill bit. Adopt a low-speed and slow-advance strategy. When necessary, combine it with pre-cracking blasting to improve the drilling efficiency.

5. Backfill soil layer: The backfill soil has a complex composition and uneven density. First, reinforce the backfill soil. During drilling, press gently and rotate slowly to enhance the mud wall protection and prevent instability and deviation of the hole wall.

6. Collapsible loess strata: Loess is prone to collapsibility when exposed to water. During construction, it is necessary to strictly control the slurry indicators, keep the water head in the hole stable, and pour concrete as soon as possible after the hole is formed to reduce the time that the loess is affected by water.

In conclusion, rotary drilling construction requires full consideration of the characteristics of the stratum and flexible adjustment of the construction methods and equipment configuration. Only by accurately grasping the key points of construction in different strata can we ensure the efficient operation of rotary drilling RIGS, guarantee the quality and safety of the project, and lay a solid foundation for all kinds of infrastructure construction.