As the subsea tunnel is designed to pass through the
complex strata and withstand high water pressure, the risk of shield chamber
intervention tends to be higher compared to general landbased
shield tunnels. Therefore, it is essential to develop a kind of safe, highly
efficient and costeffective auxiliary chamber
intervention technology. In this paper, typical technologies of freezing method
and grouting combined with paste HDN film method are introduced and applied to
the subsea tunnel projects on Lines 3 and 2 of Xiamen Metro. The recommended
methods are compared in terms of adaptability and safety based on the
hydrogeological characteristics and the previous application effect. The
construction period and cost are divided into two stages, i.e. soil
reinforcement and cutter repair, the distribution proportion of them is
analyzed, and the relationship between unit repair time (cost) and workload is
established. The analytical results show that: (1) With regard to the seabed
sandy soil layer, the quality of the existing grouting technology fails to meet
the requirements on reliability for chamber intervention under atmospheric
pressure, and it is recommended to conduct hyperbaric operation with the
assistance of paste HDN film in case of unstable strata and longterm chamber intervention; the freezing method demonstrates an
excellent adaptability to sandy soil layer and a high level of watertightness,
and which could meet the requirements of atmospheric operation under the
context of close monitoring. (2) The construction period and cost required by
the freezing method during the soil reinforcement and thawing stage exceed 1.6
times that as required by the grouting reinforcement method; while the
efficiency of welding work under atmospheric pressure inside the chamber is 7.1
times that under hyperbaric condition; thus it could be concluded that the
freezing method is more advantageous when the workload of cutter repair is
high.
DU Baoyi, SONG Chaoye, HE Weiguo
. Application Analysis of Auxiliary Technologies for
Subsea Tunnel Shield Chamber Intervention in Case of
Abnormal Cutter Abrasion: a Case Study on Subsea
Tunnel Project of Xiamen Metro[J]. Tunnel Construction, 2020
, 40(S1)
: 374
-381
.
DOI: 10.3973/j.issn.2096-4498.2020.S1.049
