Views: 0 Author: Site Editor Publish Time: 2026-08-20 Origin: Site
Rotary drilling rigs are heavy‑duty piling construction equipment characterized by massive self‑weight, wide operating radius and concentrated construction loads, which impose extremely high requirements on foundation stability and site flatness of work zones. This constitutes a core pre‑construction procedure to prevent equipment overturning and borehole wall collapse. Before official commencement, operators shall conduct a full‑scale inspection of site geological conditions with priority given to foundation bearing capacity testing. Soft soil layers, backfill zones and low‑lying waterlogged areas must be hardened, backfilled and compacted in advance to eliminate hidden risks of machine subsidence. Meanwhile, the work site shall be leveled with surrounding sundries, steep slopes and gullies cleared away, so as to ensure a horizontal and solid ground for rig operation. For construction positions close to foundation pits, slopes or river courses, safe operating distances shall be calculated beforehand, and protective fences as well as warning zones shall be set up to head‑off risks of rig overturning and borehole collapse at the source and lay a solid groundwork for subsequent standardized construction.
Non‑standard operation is the primary cause of overturning accidents during rotary drilling rig construction. Special operating specifications must be strictly followed and equipment operating conditions monitored throughout the whole process. When positioning the rig, extend all telescopic outriggers completely and place dedicated thickened bearing plates to ensure uniform force distribution on outriggers and horizontal centering of the machine body. Operation is strictly prohibited under circumstances including suspended outriggers, offset bearing forces and tilted machine body. During construction, overloaded drilling, forced pressurization and unilateral over‑load operation are forbidden to prevent unbalanced machine stress caused by deflected drill rods and drilling tools. When relocating the rig or adjusting operating positions, retract drilling tools, lower the center of gravity and move the machine slowly and steadily, and avoid dangerous maneuvers such as turning on steep slopes and rapid displacement. In addition, construction must be suspended immediately under severe weather including strong winds and heavy rains, and the rig shall be reset and fixed to avert overturning triggered by external disturbances and guarantee stable equipment operation in all aspects.
Borehole forming is a high‑incidence stage for wall collapse accidents. Complex geological formations such as loose sand, silt and silty mud are highly vulnerable to borehole spalling, collapse and hole shrinkage, which calls for refined drilling operations. Drilling speed shall be adjusted according to on‑site geological conditions; low‑speed drilling shall be adopted for fragile strata such as soft soil and sand layers, while rapid drilling and repeated tripping that disturb the borehole wall are forbidden. Keep continuous monitoring of mud parameters during construction and reasonably adjust mud density and viscosity to stabilize the borehole wall via hydrostatic mud pressure and avoid spalling of loose wall soil. Gentle movements are required during tripping, borehole cleaning and drill‑bit replacement to reduce impact disturbances to the borehole wall. Meanwhile, strictly control the water level inside the borehole and prevent wall instability and collapse resulting from excessively low water levels, so as to ensure the quality and safety of borehole forming.
Special operating scenarios such as construction adjacent to foundation pits, alternating deep‑and‑shallow hole drilling and night‑time work are prone to triggering both overturning and collapse risks, hence targeted safety control measures must be implemented. For pile bore positions with variable depths, follow the principle of drilling deep holes first before shallow ones, to prevent shallow borehole collapse induced by deep‑hole construction disturbances as well as rig inclination caused by operation across elevation gaps. Sufficient lighting shall be guaranteed for night construction to clearly identify site road conditions and borehole boundaries and eliminate irregular operations arising from blind zones. Real‑time monitoring of machine posture and borehole wall conditions shall be carried out throughout construction. Work must be halted immediately upon detection of anomalies including slight machine inclination, borehole spalling and mud leakage. Construction can only resume after hidden dangers are fully investigated and rectified, preventing minor hazards from evolving into safety accidents.
Sound on‑site management and standardized personnel operation are essential for long‑term hazard prevention. All operators must hold valid work certificates, be familiar with equipment performance of rotary drilling rigs as well as special anti‑overturning and anti‑collapse operating rules, and uncertified operation, irregular operation and fatigued work are strictly banned. A dedicated inspector system shall be implemented at the construction site, with regular inspections on key indicators including outrigger stress, machine levelness, mud status and borehole wall stability to keep construction safety under full control. In addition, core components of the rig including hydraulic systems, braking assemblies and drill‑rod structures shall be inspected and maintained periodically to avoid safety incidents caused by equipment failures. Standardized personnel administration, regular hazard investigation and normalized equipment maintenance will comprehensively strengthen safety guarantees for rotary drilling construction and promote steady and orderly progress of pile foundation projects.
