How does a front soil spiral pipe jacking machine achieve precise trenchless tunneling?
Publish Time: 2025-12-17
With increasingly limited underground space in cities and dense surface traffic and buildings, traditional "open-cut" pipeline laying methods are no longer sustainable. Trenchless technology, due to its advantages of minimal surface disturbance, high construction efficiency, and low environmental impact, has become the preferred choice for underground pipeline construction in municipal, energy, and communication sectors. As an important branch of trenchless equipment, the front soil spiral pipe jacking machine, with its unique spiral soil removal structure and intelligent guidance system, achieves efficient and controllable precise tunneling in soft soil, sand, and even medium-dense clay strata.1. Leading Edge Cutting and Spiral Soil Removal: Achieving Continuous Excavation and Efficient Excavation TransportationThe core of the front soil spiral pipe jacking machine lies in its integrated rotating cutting head and built-in spiral conveying shaft at the front end. During operation, a hydraulic motor drives the cutting disc to break up the soil in front, while the high-speed rotating spiral continuously transports loose excavated soil along the inner cavity of the pipe to the working shaft. This integrated design of "drilling and slag removal simultaneously" avoids the dependence on slurry treatment systems found in traditional slurry balance or air pressure balance pipe jacking, making it particularly suitable for short-distance, small-to-medium diameter municipal pipeline projects. More importantly, the spiral slag removal process itself has a "soil plug effect"—that is, the dense soil column formed between the spiral blades and the pipe wall can support the excavation face in the opposite direction, effectively maintaining the stability of the working face, preventing collapse or surface subsidence, and providing a stable geological prerequisite for precise advancement.2. Laser Guidance and Real-Time Attitude Feedback: Millimeter-Level Precision ControlThe key to precise traversal lies in "clear visibility and accurate control." Modern leading-edge spiral pipe jacking machines are generally equipped with high-precision laser guidance systems: a laser transmitting station is set up behind the starting shaft, and a laser receiving target is installed at the head of the jacking machine. As the equipment advances, the receiving target detects the laser spot position in real time, transmitting three-dimensional attitude data such as yaw, pitch, and roll back to the control room. Operators then adjust the jack thrust distribution or cutterhead steering mechanism accordingly, dynamically correcting the trajectory. Some high-end models also integrate tilt sensors, gyroscopes, and even GNSS-assisted positioning to construct a multi-source fusion navigation model. Even over long distances or in environments with signal obstruction, the trajectory deviation can be controlled within ±20mm, meeting stringent pipeline connection requirements.3. Modular Design and Geological Adaptability OptimizationFor different geological conditions, the leading-edge spiral pipe jacking machine can optimize tunneling parameters by changing the cutterhead type and adjusting the spiral pitch and speed ratio. For example, in high-water-content sand layers, a small pitch and high torque mode is used to enhance the sealing of slag discharge; in clay layers, the speed is increased to prevent spiral blockage. This "site-specific" flexibility allows it to adapt to various soil environments without changing the main unit, ensuring continuity and accuracy stability during crossings.4. Low-Disturbance Construction Ensures Urban SafetySince it does not require large-area excavation, the leading-edge spiral pipe jacking machine has almost no impact on roads, green spaces, existing pipelines, and surrounding buildings. Its propulsion process generates minimal vibration, and combined with real-time surface settlement monitoring, ground deformation can be controlled to the millimeter level, making it particularly suitable for traversing sensitive areas such as subway tunnels, historical buildings, or busy commercial districts.In summary, the front soil spiral pipe jacking machine, through its four technological pillars of "high-efficiency spiral soil removal + intelligent laser guidance + adaptive ground control + low-disturbance construction," has successfully achieved precise underground crossings under trenchless conditions. It not only enhances the intelligence and greening level of urban underground pipeline network construction but also redefines the new standard of modern trenchless construction with "invisible engineering, visible precision."
