In underground pipeline construction, the guided mud-water balance pipe jacking machine (TBM) achieves efficient handling of excavated soil and precise maintenance of pressure balance thanks to its unique mud-water circulation system. This system uses a mud-water mixture as a medium to both support the stability of the excavation face and transport the excavated soil, becoming a core guarantee for the efficient operation of the TBM.
The primary function of the mud-water circulation system is to form a stable mud film. When the TBM cutterhead cuts the soil, the mud-water mixture is injected into the excavation face. Under pressure, the solid particles in the mud-water form a dense mud film on the soil surface. This mud film acts as a natural barrier, effectively preventing groundwater from seeping into the excavation face while balancing the soil and water pressure, preventing excavation face collapse or ground subsidence. The formation of the mud film depends on the precise control of mud-water density and pressure, and needs to be dynamically adjusted according to geological conditions to ensure it adapts to the construction needs of different strata.
Excavated soil handling is another key aspect of the mud-water circulation system. After the excavated soil is mixed with the mud-water, it is transported to the surface treatment system through a mud discharge pipeline. In this process, the slurry circulation system, through a rational flow rate design, ensures that the excavated soil is uniformly suspended in the pipeline, preventing sedimentation and blockage. The surface treatment system typically uses a combination of vibrating screens and hydrocyclones to grade and separate the slurry mixture. The vibrating screen first removes larger particles of excavated soil, while the hydrocyclones further separate finer particles, ensuring complete separation of the slurry and excavated soil. The separated excavated soil is transported off-site, while the purified slurry is reinjected into the pipe jacking machine for recycling.
Maintaining pressure balance is the core task of the slurry circulation system. The system monitors the slurry pressure at the excavation face in real time and compares it with the ground pressure, automatically adjusting the slurry injection and discharge rates. When the pressure at the excavation face is too high, the system increases the discharge rate to reduce the slurry pressure; when the pressure is too low, it increases the slurry injection rate to increase the pressure. This dynamic adjustment mechanism ensures that the excavation face remains stable, avoiding construction risks caused by pressure imbalance. Simultaneously, the system is also equipped with an emergency pressure-maintaining device, which intervenes quickly in case of emergencies to maintain pressure stability and ensure construction safety.
The mud-water balance pipe jacking machine's slurry circulation system also features lubrication and drag reduction. High-pressure mud-water forms a lubricating film on the outer wall of the pipe section, significantly reducing frictional resistance during jacking. This lubricating film not only reduces energy consumption but also extends the pipe section's service life. Furthermore, the lubricating film makes the jacking process smoother, reducing vibration and noise caused by friction, thus improving construction comfort and environmental friendliness.
In complex geological conditions, the adaptability of the mud-water circulation system is particularly important. The system can achieve precise construction by adjusting the mud-water ratio and pressure parameters according to different strata characteristics. For example, in gravel strata, the system uses high-density mud-water to enhance the support of the mud film; in soft soil strata, the mud-water density is reduced to minimize disturbance to the strata. This flexible adjustment capability allows the guided mud-water balance pipe jacking machine to cope with various complex geological conditions, ensuring smooth construction.
Intelligent control of the mud-water circulation system is also key to its efficient operation. The modern guided mud-water balance pipe jacking machine is equipped with an advanced monitoring and control system capable of collecting and analyzing construction data in real time and automatically adjusting mud-water circulation parameters. Operators can remotely control the system and receive fault warnings simply by monitoring its operation through a control interface. This intelligent control not only improves construction efficiency but also reduces the risk of human error, enhancing the safety and reliability of the construction process.
The guided mud-water balance pipe jacking machine's mud-water circulation system achieves efficient waste disposal and precise pressure balance maintenance through multiple mechanisms, including mud film formation, waste disposal, pressure balance maintenance, lubrication and drag reduction, geological adaptability adjustment, and intelligent control. This system not only enhances the construction performance of the pipe jacking machine but also provides reliable technical support for underground pipeline construction under complex geological conditions.
