Feasibility Analysis of Freezing Method in Strong Permeability Strata

Abstract

If the underground engineering meets the strong permeable strata, such as sand and pebble strata, it will face huge challenges. Effective sealing of water has become a prerequisite for determining the safety of the project. Freezing method is currently an effective method for dealing with complex permeable strata, however, the influence of the groundwater velocity on the freezing engineering is huge. If the groundwater flow rate is too high, the freezing cannot be completed normally. Therefore, for the freezing project of strong permeable formation, the speed and flow direction of groundwater is a focus of our research. The connecting channel at the bottom of the river of Fuzhou Metro is planned to be constructed by freezing method. The main soil layers are the strong permeable strata represented by the coarse medium sand layer and the pebble layer. Therefore, the measurement of the velocity and direction of the groundwater at the bottom of the river was carried out, and the influence of the groundwater on the freezing project was judged based on the measurement results. If the groundwater velocity is too high, normal freezing cannot be achieved. Referring to the form of the cofferdam, a composite reinforcement method is proposed.