Field Temperature Data Analysis of the Water Resistance Performance of Freeze-Sealing Pipe Roof Used in Tunnel through Water-Rich Strata

A new presupporting technology named freeze-sealing pipe roof (FSPR) method was adopted in the construction of Gongbei tunnel (Zhuhai, P.R. China), which was a critical part of Hong Kong-Zhuhai-Macau Bridge (HZMB). The method combined the pipe-roofing with artificial ground freezing (AGF). The water resistance performance of FSPR surrounded by water-rich soils was studied based on the field temperature data. The time-dependent temperature changes of the frozen soil between two adjacent pipes were presented, and the thicknesses of the frozen soil in different freeze period were calculated. Besides, the remote temperature monitoring system used in this field research was presented systematically. The thermal effects of the Hurricane Nicole on the frozen soil wall were also observed. The results showed that the closure of frozen soil wall can be classified into two different modes. The frozen soil between the pipes before excavation had met the design requirements before excavation, and the FSPR maintained satisfied water resistance performance.