Abstract: A water-inrush accident broke out in the main shaft of Wu-ju coal mine when it was constructed at -223.7 m level, the max quantity of gushing water was 360.97 m3/h, the depth of flooded shaft was 145.64 m. The construction technology of concrete waterproof pad under water was proposed, the underwater concrete waterproof pad was built successfully and the water-inrush accident was managed quickly and effectively. Compare with freezing method, it shortened the construction period and saved about 100 million engineering cost. The successful practice of this construction technology provide valuable experience for water-inrush controlling while shaft construction in the similar geological conditions.

Key words: vertical shaft, ordinary construction, water inrush, waterproof pad, face pre-grouting