Tunnel structure suitable for gypsum salt stratum and construction method

Abstract

The invention discloses a tunnel structure suitable for a gypsum salt stratum and a construction method. The tunnel structure sequentially comprises a supporting layer, a waterproof layer and an anti-corrosion lining from outside to inside; the supporting layer is laid along the excavated surrounding rock, a deformation layer is arranged between the supporting layer and the waterproof layer, the deformation layer is only arranged along an arch ring, no deformation layer is arranged at an inverted arch, and an out-hole drainage system is arranged on the outer side of the center of the bottom of the supporting layer. According to the tunnel structure, the damage to the tunnel when the gypsum salt stratum expands is overcome; effective drainage is achieved through the out-hole drainage system and an annular drainage system, the overall water head around the tunnel is lowered, out-hole water does not enter the tunnel and is directly drained away, and the possibility that a tunnel body structure is corroded is lowered; the corrosion resistance of the tunnel body structure is further enhanced through the corrosion-resistant lining; and the problems of tunnel concrete cracking, corrosion loosening, stripping and chipping and the like can be effectively solved, and the collapse risk caused by extrusion and corrosion of a tunnel structure is avoided.

Description

technical field [0001] The invention relates to the technical field of civil engineering, in particular to a tunnel structure and construction method suitable for gypsum-salt formations. Background technique [0002] In the field of civil engineering, the drilling and blasting method is often used for tunnel excavation. Various complex strata will be encountered during tunnel excavation, including karst section, gas section, rockburst section, gypsum-salt section, etc. The gypsum-salt strata of the Triassic Badong Formation in Southwest my country are widely distributed. Many deep-buried tunnels built in the Three Gorges Reservoir area pass through the gypsum-salt section, and the tunnels have problems such as concrete corrosion, loosening, and spalling. [0003] The influence of the gypsum-salt formation on the tunnel structure is more complicated, and its harm to the tunnel structure mainly has two aspects. On the one hand, the gypsum-salt formation has water swelling pro...

AI Technical Summary

Problems solved by technology

On the one hand, the gypsum-salt formation has the property of swelling when it encounters water. After the tunnel is excavated, there is an empty surface. The gypsum-salt formation will gradually expand when it encounters groundwater, and the lining structure will be squeezed, causing the tunnel lining to crack or even collapse.

On the other hand, the gypsum-salt formation is corrosive, and when the waterproof system of the tunnel structure is not perfect or is partially damaged, it will cause the tunnel lining and concrete to be corroded and damaged

The corrosion damage to the tunnel structure in the gypsum-salt stratum does not occur immediately, so it is more concealed. When the tunnel structure is corroded to a certain extent, it is easy to cause safety accidents and property losses

Images