Construction Precautions for Bored Cast-in-place Piles in Karst Areas

In karst areas, the construction of bored cast-in-place piles is carried out under complex geological conditions, which impose extremely high requirements on construction techniques. Rotary drilling RIGS have become commonly used equipment due to their advantages such as high efficiency and precision, but improper operation can easily cause problems. Here is a detailed introduction to the six major points to note during construction.

1. Pre-construction investigation: Through means such as geological radar and drilling, conduct a detailed investigation of karst distribution, cave size and filling material conditions to clarify geological structures and provide a basis for the formulation of construction plans.

2. Equipment selection and adaptation: Based on the survey results, select the appropriate model of rotary drilling rig to ensure that the strength and torque of the drill pipe and drill bit meet the construction requirements and cope with complex geological conditions.

3. Stable burial of the casing: A long casing is adopted to pass through the karst development layer, ensuring that the bottom of the casing is embedded in a stable stratum, preventing the collapse of the hole wall and the leakage of mud, and guaranteeing the safety of hole formation.

4. Mud performance control: Reasonably adjust the specific gravity, viscosity and sand content of the mud to form effective wall protection in karst cavities, avoiding hole collapse and diameter reduction problems.

5. Drilling speed control: Slow down the drilling speed when approaching the cave, closely observe the load of the drilling rig and the conditions inside the hole to prevent stuck or dropped drilling accidents.

6. Rigorous hole formation inspection: After hole formation, ultrasonic testing instruments and other equipment are used to comprehensively inspect the hole diameter, verticality and hole depth to ensure that the quality of the pile body meets the design requirements.

In conclusion, when using rotary drilling RIGS for bored cast-in-place pile construction in karst areas, every step from the initial investigation to the hole formation inspection is of vital importance. Only by strictly controlling these precautions can we ensure the safe and efficient progress of construction and guarantee the reliable quality of pile foundation projects.