Upper-blocking and lower-draining construction method for undersea tunnel fault fracture zone

Abstract

The invention relates to the technical field of underground engineering construction, and discloses an upper-blocking and lower-draining construction method for an undersea tunnel fault fracture zone. The method comprises the following steps of: rapidly grouting the upper half section of a tunnel for reinforcing, forming inspection holes according to 3-5 percent of number of grouting holes, drilling drainage inspection holes on the lower half section of the tunnel, and excavating and supporting on the upper half section of the tunnel when the maximum water inflow of a single inspection hole is lower than a predetermined standard; and rapidly excavating on the lower half section of the tunnel, and enclosing the initial support of the tunnel into a ring in time to safely and smoothly pass through the fault fracture zone and ensure that the tunnel is free from leakage basically. The construction method is suitable for an undersea tunnel fault fracture zone or a broken rock stratum developed from a water-rich crack; and construction is performed in an enclosed structure, so that the safety of tunnel excavation construction is ensured, the work amount of drilling, grouting, reinforcing and blocking water is reduced, and the requirement of drainage prevention is met. The construction method has the advantages of high construction efficiency, low cost and contributes to saving investment and time for successful building of the tunnel.

Description

technical field [0001] The present invention relates to the technical field of underground engineering construction, in particular to a kind of subsea tunnel fault fracture zone upper and lower plugging when the subsea tunnel passes through the water-rich fault fracture zone and the cracked rock mass when the upper half section is grouted for water blocking and the lower half section is excavated for drainage Row construction method. Background technique [0002] Due to the continuous growth of the economic strength of my country's coastal cities, the rapid development of urban construction, and the continuous expansion of urban scale, there will be many submarine tunnels or underwater tunnels in coastal areas. Building tunnels on the seabed will face more serious groundwater prevention and control problems than those on land. Subsea tunnels are generally large in scale and have a tight construction period. Once mud and water inrush occur, the consequences will be unimaginab...

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Problems solved by technology

[0005] The freezing method is a method that uses refrigerant to transfer cold energy to cool the water-bearing strata to freeze, and relies on the strength of the frozen rock and soil to bear the pressure of the surrounding rock, so that the excavation and support can be carried out safely under the protection of the frozen rock and soil. The method is expensive and has a long operating cycle, and is usually applied to formations that cannot be used by other methods

[0006] Some of the above methods have a long

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