Common Problems and Emergency Handling Measures in Rotary Drilling Rig Drilling

    Rotary drilling rigs, as key equipment for hole-forming operations in pile foundation engineering, are prone to problems such as drilling jamming and hole deviation during construction in complex formations. These issues not only affect the efficiency of hole formation and the quality of pile formation but may also lead to potential safety hazards such as equipment damage and hole collapse. Timely identification of the causes and standardized implementation of emergency treatments are crucial to ensuring the continuous and stable progress of pile foundation construction.

    Drilling jamming is mostly caused by sudden changes in the formation, rock block jamming, slag reflux, and uneven resistance of the drilling bucket. When jamming occurs, pressure application should be stopped immediately to avoid drill pipe distortion or equipment overload due to forced drilling. The drilling bucket can be lifted slightly, rotated gently to shake off attached slag, and then slowly lowered for tentative drilling. If jamming is caused by boulders or hard rock interlayers, it is necessary to replace with a short auger bit or a cylindrical core bit, and adopt low rotational speed and small feed rate for step-by-step crushing. In case of drilling jamming caused by soft plastic clay or silty clay sticking to the drill, the drill should be lifted in time to clean the accumulated soil on the teeth and side walls of the drilling bucket, optimize the mud performance, enhance the ability of wall protection and slag carrying, so as to prevent secondary jamming caused by slag reflux.

    Hole deviation is mostly related to uneven hardness of the formation, uneven base of the drilling rig, wear of the drill pipe, and excessive pressure application. Before hole formation, the site should be leveled and compacted, the levelness of the drilling rig and the verticality of the drill pipe should be calibrated, and it should be ensured that the mast is aligned with the center point of the pile position. During the drilling process, uniform pressure should be maintained to avoid hole inclination caused by excessive unilateral force. If a slight hole deviation has occurred, the hole slope can be corrected slowly by repeatedly sweeping the hole up and down; in case of severe deviation, backfill clay and gravel to above the deviated section, and re-drill at low speed with stable pressure to gradually correct the hole position. For formations prone to hole deviation such as pebble layers and weathered rocks, longer guide bits with stronger guidance should be selected to improve the verticality of the formed hole.

    During the construction process, it is necessary to strengthen process control, formulate targeted drilling parameters in advance according to the geological survey report, reasonably select the type of drill bit, and strictly control the drilling speed and pressure. Strengthen the inspection of key components such as drill pipes, drilling buckets, masts, and hydraulic systems, and timely replace components with excessive wear to ensure good operation status of the equipment. At the same time, optimize the mud ratio, maintain the water head pressure in the hole, enhance the stability of the retaining wall, and reduce the interference of hole collapse and diameter reduction on the drilling attitude.

    Operators must work with certificates, proficiently master the drilling characteristics of different formations and key points of emergency disposal, stop the machine in time to check when abnormalities are found, and strictly prohibit illegal operations. Through the combination of early prevention, process control, and rapid response, problems such as jamming and hole deviation can be effectively reduced, the quality of hole formation and construction efficiency can be improved, and the safe and orderly progress of pile foundation engineering can be guaranteed.