Abstract：
The pre-supporting system of the Gongbei tunnel situated at the Zhuhai Link of the Hong Kong-Zhuhai-Macao Bridge, was constructed by a new construction method, the Freeze-Sealing Pipe-Roof (FSPR) method, which combines pipe-roof reinforcement with artificial freezing technology. According to practical conditions, this paper proposes for the first time a freezing scheme composed of three special types of pipes arranged inside the steel tubes of the pipe-roof system, i.e. the circular main freezing pipe, the specially shaped intensive freezing pipe, and the heat brine pipe for limiting the over-growth of the frozen body. A large-scale physical model test was carried out to study the validity and controllability of this freezing scheme. This paper briefly introduces the model test, focusing on the experimental study of the freezing effects at an active freezing stage before excavation. The test results show that the development of a frozen curtain is of expected regularity, the freezing effect is remarkable, and the frozen curtain is formed between pipe roofs, which guarantees a good sealing effect.
HU Xiang-Dong-1,
2 ,
REN Hui-1 etc
.Model Test Study of the Active Freezing Scheme for the Combined
Pipe-Roof and Freezing Method
[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(5): 92-98
2014, Vol. 51 