The Optimization of Waterproof and Drainage Design and an Evaluation of the Structural Safety of Tunnels in Weak Watery Strata

Abstract

The surrounding rock and high water pressure in weak watery strata have adverse effects on the mechanical properties of tunnel support structures. In order to optimize the anti-drainage design of tunnels in weak watery strata and evaluate their structural safety, this paper relies on the Taidacun Tunnel of the China–Laos Railway to carry out field monitoring research. A dual-field fluid–solid coupling calculation model is established to optimize the tunnel’s waterproof and drainage design, combined with a bending moment curvature model to evaluate structural safety. The main conclusions are as follows: Under the action of high water and soil pressure, the structural safety margin of the water-rich fine sand section of the Taidacun Tunnel is small, and waterproof and drainage design optimization is required. Combined with the proposed average pressure reduction coefficient, the influence of the water level and annular blind pipe spacing on the water pressure of the lining is proved, and then the optimal annular blind pipe spacing in the water-rich area of the tunnel is determined. A structural safety evaluation method based on the bending moment curvature model is proposed. Two models of elastic beam and moment–curvature beam are used to analyze the mechanical characteristics and optimization effects of the structure under optimal annular blind pipe spacing.

Study on safe crossing in the dry season and an anti-floating drainage scheme in the wet season: a case study in Guiyang, Southwest China

“…Zhou established a two-field fluid‒structure coupling calculation model based on the field monitoring results of the Taidacun tunnel on the China–Laos Railway to optimise the waterproofing and drainage design of tunnels with weak water-cut formations. Zhou also demonstrated the influence of the water level and annular blind tube spacing on the lining water pressure and determined the optimal distance of annular blind tubes in water-rich zones of the tunnel 38 . Using Norwegian rail and road tunnels as examples, Holter introduced a composite tunnel lining system based on a sprayed waterproofing membrane combined with sprayed concrete.…”

A Variable-Weight Model for Evaluating the Technical Condition of Urban Viaducts

“…The current focus of the resilience concept in transportation infrastructure management lies primarily in ensuring facility safety. This includes activities such as safety assessment [18], safety-risk assessment [19,20], and safety-risk prediction [21][22][23]. Scholars have extensively examined and analyzed the safety-risk factors in various road transportation infrastructures, mainly for bridges [24] and tunnels [25].…”