Water in rush Analysis and Manage Measures of Shaft Sinking by Freezing Method

The freezing method provides a powerful technological support for the shaft sinking through the thick Quaternary with plenty of water and sand layers. Grouting by perforation inside the freezing holes can efficiently stop the water passageway from the Quaternary phreatic acquifer to the crevice water in the bed rock and enforce the shaft wall, control the damages occurred such as water inrush or shaft wall declination. Since the plenty of river system and the huge thickness of the Quaternary, 16 shafts of Tianxing iron mine were tunneling by the freezing method, several times of water inrush still occurred. This study summarizes the total water inrush accidents during shafts tunneling, lists the shafts purpose, the construction technology, the point of water inrush and the time joint, analyze the common rules of the water inrush. In an engineering case, based on the thoroughly understanding the complex relationships between the water inrush and the hydrological condition and the construction technology and the insufficient of the prophase engineering, using a tunnel designing program in a software of geotechnical engineering, the appropriate grouting pressure was confirmed, which was a key problem to carry out the project of grouting and finally successful controlled the serious water inrush while the shaft was tunneling just throughout the frozen layer. The experience can be used for reference for the same typical mines.