Development and Application of a New Reduction Coefficient of Water Pressure on Sub-Sea Tunnel Lining

Abstract

Limited drainage tunnels face pore water pressure, water inflow, and permeability challenges. At present, there is little systematic analysis and research on the lining water pressure of sub-sea tunnels, and there is a lack of verification of relevant engineering examples and field monitoring data. Based on the numerical simulation method, this paper discusses the lining water pressure and its reduction coefficient of the horseshoe section tunnel, which is verified by an engineering example. Based on many numerical simulations, the recommended value of the water pressure reduction coefficient considering the thickness of the grouting ring and grouting effect is put forward. The stress law and safety of tunnel lining under different water reduction coefficients are studied, and the safety of lining is evaluated combined with the measured data of lining stress. The results show that the numerical simulation has been well verified. Considering the water pressure according to the water pressure reduction coefficient method proposed in this paper can ensure the structural safety of tunnel lining. The method of lining water pressure reduction coefficient proposed in this paper can provide a reference for the subsequent lining design of the sub-sea tunnel.

Analytical Solution for Water Inflow into Deeply Buried Symmetrical Subsea Tunnels with Excavation Damage Zones

“…The hydraulic head distribution still obeys Equation (10) for EDZs, and the water inflow into the tunnel is given below:…”

“…Scientific assessments of the water inflow are critical but arduous for subsea tunnels [6,7]. Due to the unlimited water supply above subsea tunnels, inaccurate predictions of the water inflow can lead to severe water ingress disasters or an overly conservative design of the drainage system [8][9][10][11]. Hence, considerable efforts have been devoted to water inflow assessments that employ analytical [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], empirical [28,29], and numerical [30][31][32] methods.…”

A Comparative Study on Steady-State Water Inflow into a Circular Underwater Tunnel with an Excavation Damage Zone

“…As an important option of underwater transportation engineering, underwater tunnels have the advantages of insensitivity to weather, no obstruction of navigation, good seismic performance and little impact on ecosystems. Hence, a considerable number of underwater tunnels have been constructed in the past century [1][2][3]. The estimation of water inflow is a key and difficult issue for underwater tunnels due to infinite water supply and defects of water-proofing systems [4][5][6][7].…”