Sealing and water stopping structure applied to high-water-pressure unconsolidated stratum shield tunnel receiving tunnel portal and construction method

Abstract

The invention discloses a sealing and water stopping structure applied to a high-water-pressure unconsolidated stratum shield tunnel receiving tunnel portal and a construction method. The sealing and water stopping structure is arranged in an annular space between a steel segment and a tunnel portal outward-stretching ring beam, and comprises a bottom plate, an inner side fixing ring, an outer side fixing ring, an annular tightening inhaul cable and a stress application pressing screw rod; the outer side fixing ring is pre-buried in the tunnel portal outward-stretching ring beam; the inner side fixing ring is fixed to the bottom plate; the annular tightening inhaul cable is alternately arranged between the inner side fixing ring and the outer side fixing ring in a penetrating mode; and the stress application pressing screw rod is arranged on the tunnel portal outward-stretching ring beam. A steel cable+stress application screw+bottom plate structure is arranged between the tunnel portal ring beam and the steel segment, a space steel cable net is formed between the tunnel portal ring beam and the special steel segment after a shield receives through telescopic deformation of the structure, and water and soil pressure outside the tunnel portal is permanently resisted by injecting concrete, so that a shield receiving end stratum reinforcement measure is omitted, the construction cost is reduced, and the influence on the surrounding environment is reduced.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering construction, in particular to a sealing water-stop structure and a construction method corresponding to a receiving portal of a shield tunnel in a high water pressure loose stratum. Background technique [0002] With the vigorous development of urban subway tunnels, cross-river and sea-crossing traffic tunnels, water conservancy and hydropower tunnels, municipal public tunnels and other tunnel projects, more and more tunnels need to cross rivers, lakes and seas. Originating and receiving in the ground layer. The construction technology of shield tunnel entry and exit involves the design of the sealing door of the working well, the reinforcement of the soil outside the sealing door, the performance of the shield machine and the accuracy of the guiding system, etc. It is a difficult problem in the construction of shield tunnels. Accidents such as collapse are key procedures in the const...

AI Technical Summary

Problems solved by technology

[0004] Due to the uncertainties in the reinforcement effects of various stratum reinforcement methods in the current engineering field in sandy soil layers with high hydraulic pressure, especially in the environment where groundwater is flowing The knot then forms a weak zone, causing water and sand gushing when the cave door is broken

In addition, the existence of gaps in the tail of the shield will inevitably create groundwater communication channels

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