Views: 0 Author: WU Publish Time: 2024-12-26 Origin: Site
Rotary drilling rigs are widely used in construction engineering, especially in rock drilling operations where their efficiency and flexibility are fully demonstrated. However, rock drilling imposes higher demands on equipment and techniques. To ensure efficiency and quality, certain basic conditions must be met, including equipment performance, tooling selection, geological surveys, and proper planning of construction techniques. The following is a detailed analysis of these basic conditions.
Rock drilling requires high-performance rotary drilling rigs designed for challenging geological conditions.
Engine Power: The rig must deliver strong power output, usually requiring engine power of 300kW or more to provide sufficient torque and pressure during drilling.
Torque of Rotary Head: Torque is a critical factor for rock penetration. Typically, rock drilling requires a rotary head torque of over 250kN·m.
Hydraulic System: A high-pressure and stable hydraulic system is essential to support prolonged operations and avoid overheating or failures.
Drilling tools, which directly interact with the rock, significantly influence the efficiency of rock penetration.
Drill Bit Type: Choosing the right drill bit is crucial, such as roller bits, composite bits, or diamond bits. Harder rocks require more wear-resistant drill bits.
Drill Rod Strength: Drill rods must withstand significant pressure and impacts, requiring high-strength, fatigue-resistant materials to prevent deformation or fracture.
Casing Coordination: In shallow rock layers or complex geology, casings are used to stabilize the borehole and prevent collapse or deviation.
Comprehensive geological surveys are prerequisites for rock drilling. Understanding rock characteristics and distribution aids in selecting appropriate equipment and techniques.
Rock Hardness: The uniaxial compressive strength (UCS) of the rock determines its drilling difficulty; the harder the rock, the greater the challenge.
Fissures and Joints: Rock fissures and joints significantly affect drilling operations, potentially causing bit deviation or equipment vibration.
Groundwater Conditions: In water-rich rock layers, measures like dewatering or slurry stabilization are necessary.
Scientific planning and proper operation are critical to improving efficiency and minimizing equipment wear during rock drilling.
Controlled Drilling Speed: In hard rock, reduce the drilling speed and increase torque and pressure to ensure effective rock cutting.
Mud Circulation: Mud plays a vital role in rock drilling. An efficient mud system cools the drill bit, lubricates the drill rod, and removes debris, ensuring borehole stability.
Layered Drilling: For varying rock hardness, adopt a layered drilling approach to reduce equipment impact and achieve deeper penetration gradually.
Rock drilling operations place significant wear on the rig, necessitating thorough maintenance.
Drill Bit Inspection: Worn or damaged bits directly affect drilling efficiency and should be regularly checked and replaced.
Hydraulic System Maintenance: Ensure the hydraulic system operates smoothly by keeping oil circuits clear and replacing hydraulic oil as needed.
Rotary Head Care: Inspect gears and bearings in the rotary head for wear and lubricate or replace them as necessary.
Skilled operators are essential for successful rock drilling.
Proficient Operation: Operators must be proficient in controlling the rig, particularly the rotary head and hydraulic system.
Handling Emergencies: Quick judgment and action are required to address issues like borehole collapse or bit jamming.
Construction Records: Maintain detailed records of each operation for performance evaluation and improvement.
Rotary drilling rigs require comprehensive preparation in equipment, tooling, geology, and techniques for rock drilling operations. High-performance equipment, proper tool selection, thorough geological surveys, and sound construction techniques are vital to ensuring successful operations. Furthermore, regular maintenance and skilled operators enhance efficiency and extend equipment lifespan, ensuring optimal performance in challenging conditions.
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