Abstract The prefabricated vertical drains are widely used for reinforcing soft soil foundation, but its high tough? ness, corrosion resistance and non-degradability can be very bothering to later shield tunnelling in the stratum. To solve this problem, the simulation model for different cutters that are used to cut the sludge stratum reinforced by prefabricated vertical drains has been created by using the ABAQUS finite element analysis software, and the cutting results of different cutters have been compared from the aspects such as cutting force and variation characteristics.The analysis reveals how the cutting force of sharp-edged tearing cutter will be affected by the factors including cutter width, cutting edge height, cutting speed and cutter penetration. The study shows that the scraper is suitable for sludge stratum, while the sharp-edged tearing cutter is suitable for cutting prefabricated vertical drain and the width of the sharp-edged tearing cutter should not be less than 50 mm, but the regular 70 mm width will meet the construction requirements; the cutting edge height should preferably be 40 mm or 50 mm; the faster the cutterhead ro? tates, the better the cutting performance, and the rotating speed should not be less than 400 mm/s; the cutter penetration must be strictly controlled, to protect the cutter from damage caused by excessive or unstable force. For the sludge stratum containing prefabricated vertical drains, the combined cutters composed of sharp-edged tearing cutter and scraper is helpful for shield tunnelling.
Abstract：
The prefabricated vertical drains are widely used for reinforcing soft soil foundation, but its high tough? ness, corrosion resistance and non-degradability can be very bothering to later shield tunnelling in the stratum. To solve this problem, the simulation model for different cutters that are used to cut the sludge stratum reinforced by prefabricated vertical drains has been created by using the ABAQUS finite element analysis software, and the cutting results of different cutters have been compared from the aspects such as cutting force and variation characteristics.The analysis reveals how the cutting force of sharp-edged tearing cutter will be affected by the factors including cutter width, cutting edge height, cutting speed and cutter penetration. The study shows that the scraper is suitable for sludge stratum, while the sharp-edged tearing cutter is suitable for cutting prefabricated vertical drain and the width of the sharp-edged tearing cutter should not be less than 50 mm, but the regular 70 mm width will meet the construction requirements; the cutting edge height should preferably be 40 mm or 50 mm; the faster the cutterhead ro? tates, the better the cutting performance, and the rotating speed should not be less than 400 mm/s; the cutter penetration must be strictly controlled, to protect the cutter from damage caused by excessive or unstable force. For the sludge stratum containing prefabricated vertical drains, the combined cutters composed of sharp-edged tearing cutter and scraper is helpful for shield tunnelling.
WANG Dahai1 HU Yanfeng2
.Study on Type Selection and Parameter Optimization of the Shield Cutters Used for Cutting Sludge Stratum Containing Prefabricated Vertical Drains[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(3): 74-80
2023, Vol. 60 