Research Article

Site Measurement and Study of Vertical Freezing Wall Temperatures of a Large-Diameter Shield Tunnel

Table 2

Design parameters of verticle ground freezing.

NameParameter valueNameParameter value

Freezing pipeφ127 × 5 mm 20# low-carbon steel seamless steel pipeSaline temperature−28∼−30°C
Feeding pipeφ48 mm × 3.5 mm seamless steel pipeVaporization point−33∼−35°C
Temperature measurement pipeφ45 × 3 mm seamless steel pipeFreezing zone original stratum temperature≤+30°C
Hole number57 vertical freezing holes and 6 temperature measuring holesCooling water temperature+23°C
Depth of freezing hole31.2 mCondensation temperature+35°C
Total length of freezing hole1775.7 mCooling loss coefficient1.2
Total length of temperature measuring hole93.5 mTotal required coolingQ = 22.7 (10,000 calories per hour)

The original stratum temperature refers to the temperature after curing for 28 days.