Views: 0 Author: Site Editor Publish Time: 2025-10-30 Origin: Site
As the core equipment for pile foundation construction, rotary drilling rigs pose risks of overturning and collapse during operation. These risks not only may cause equipment damage but also directly threaten the life safety of construction personnel. Combining the risk characteristics observed in construction practice, it is necessary to start from the root causes of hidden dangers, establish systematic operating specifications, and strengthen safety defenses.
Technical selection: Comparison of brand advantages of rotary drilling rigs - Intelligent, power system, and energy-saving technology. The overturning of rotary drilling rigs is mainly caused by insufficient foundation bearing capacity, unbalanced equipment stress, and improper operation, and risks need to be avoided through full process control. Before construction, special treatment should be carried out on the work site: first, the soft soil, hidden pits, and obstacles in the site should be removed. For areas with insufficient bearing capacity, crushed stone cushion or lime soil layer by layer compaction should be used to ensure that the foundation bearing capacity is not less than 1.2 times the rated requirement of the equipment; At the same time, level the site and control the ground slope within 3 ° to avoid equipment center of gravity deviation caused by site inclination.
During the equipment positioning stage, it is necessary to strictly follow the principle of "leveling stability": use a level to calibrate the drilling rig chassis, ensuring that the longitudinal and transverse horizontal deviations do not exceed 0.5 °; When extending and retracting the track, it is necessary to ensure that the track is fully extended and tightly attached to the ground. The tension of the track should be such that there is no obvious depression when pressing the track plate; If the construction site is restricted, warning signs should be set up within the turning radius of the drilling rig to prohibit non operators from entering and prevent imbalance caused by obstacles during the turning process.
During the homework process, the key points of operation need to be accurately controlled: when drilling, the verticality of the drill pipe should be controlled, and the verticality monitor should be used to adjust it in real time to avoid lateral forces caused by the inclination of the drill pipe; When lifting the drilling bucket, it should be lifted slowly and sudden acceleration or direction change is strictly prohibited. The lifting weight should not exceed 90% of the rated lifting weight of the equipment; When encountering severe weather such as strong wind (force over 6) and rainstorm, the operation shall be stopped immediately, the drill pipe shall be withdrawn, the drill rig shall be transferred to a flat and solid safety area, and wind proof fixing measures shall be taken.
The hidden dangers of collapse mainly focus on the collapse of borehole walls and surrounding soil, and need to be addressed from three aspects: geological adaptation, wall protection measures, and process monitoring. Before construction, a special plan should be developed based on the geological survey report: for cohesive soil layers, dry drilling can be used to form holes, but the drilling speed should be controlled to avoid instability of the hole wall caused by too fast drilling; For sand and gravel layers that are prone to collapse, mud wall protection must be used. The mud density should be adjusted according to geological conditions, usually controlled between 1.1-1.3, and the viscosity should not be less than 18 seconds to ensure that the mud can effectively balance the pressure on the borehole wall.
During the drilling process, it is necessary to strengthen the monitoring of hole depth, hole diameter, and mud indicators: every 1-2m of drilling, the mud density and viscosity should be tested, and if the indicators are abnormal, they should be adjusted in a timely manner; After the hole is formed, it is necessary to lift the steel cage and pour the concrete as soon as possible to avoid prolonged exposure of the hole wall, with an interval of no more than 24 hours. When pouring concrete, the depth of the conduit should be controlled between 2-6m to prevent mud from mixing into the concrete due to insufficient conduit depth, affecting the quality of the pile and causing collapse of the hole wall.
In addition, environmental control in the surrounding area is also crucial: the distance between the drilling location and existing buildings and underground pipelines must meet safety requirements. If the distance is close, protective measures such as curtain grouting should be taken; During the construction process, it is necessary to regularly monitor the surrounding ground settlement. If the settlement exceeds the warning value (usually 30mm), the operation should be stopped immediately, the cause should be investigated, and reinforcement measures should be taken to prevent the collapse accident from expanding.
