CN113187515B - Tunnel secondary lining with assembled UHPC structure as bottom die and construction method thereof - Google Patents

Abstract

The invention relates to a tunnel secondary lining with a prefabricated UHPC structure as the bottom form, including UHPC rib beam sections assembled on the left wall section, right side wall section and vault section of the tunnel tunnel respectively. A prefabricated UHPC structure is formed, which is used as the base form of the secondary lining of the tunnel, and the base form is integrated with the external reinforcement mesh of the secondary lining. By giving full play to UHPC's ultra-high compressive strength, high crack resistance, impermeability, freeze-thaw resistance, and high durability, the dimensional accuracy and quality of prefabricated segmental components can be guaranteed; mechanized assembly in the hole can shorten the Construction period and improved working conditions; assembled into a ring, it can be used as a demolition-free formwork for pouring concrete, and bear the self-weight of grouting and cast-in-place concrete, reducing the workload of tying the steel skeleton in the inner cavity, and saving a lot of supporting materials and labor. At the same time, the invention has simple structure, reasonable design and convenient construction, can be widely used in tunnel structures, and improves construction efficiency and service life.

Description

Tunnel secondary lining with prefabricated UHPC structure as base form and its construction method

technical field

The invention relates to a secondary lining of a tunnel using an assembled UHPC structure as a base form and a construction method thereof.

Background technique

Tunnels are a very important part of my country's transportation infrastructure. Existing tunnels have harsh construction conditions, numerous construction procedures, and difficult construction quality assurance, especially frost damage, water leakage, lining cracks, and exposed steel bars on the inner side of the secondary lining of the tunnel. and other diseases, which increase the operation and maintenance cost and reduce the service life.

Contents of the invention

In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a secondary lining of a tunnel with a prefabricated UHPC structure as the bottom form and a construction method thereof.

In order to solve the above-mentioned technical problems, the technical solution of the present invention is: a secondary lining of the tunnel with the assembled UHPC structure as the bottom formwork, including the left wall section, the right wall section and the vault section respectively assembled in the tunnel tunnel. The UHPC ribbed beam segment of the section forms a prefabricated UHPC structure as a whole, which is used as the bottom formwork for the secondary lining of the tunnel. The inside of the bottom formwork is integrated with the outer reinforcement mesh of the secondary lining.

Preferably, the UHPC rib beam segments of the left wall segment and the right wall segment are respectively assembled to the left and right ends of the invert, and the invert is a prefabricated or cast-in-place reinforced concrete structure.

Preferably, the UHPC rib beam segment of the vault segment is suspended and assembled to the UHPC rib beam segment corbels of the left wall segment and the right wall segment, forming a ring-to-ring loop along the longitudinal direction of the tunnel. Fabricated UHPC structure.

Preferably, the joints between the UHPC rib beam segments and the inverted arches of the left wall segment and the right wall segment need to be connected with anchor rods, and the joints of adjacent UHPC rib beam segments need to be connected with anchor rods. All joints are provided with waterproof gaskets.

Preferably, the UHPC ribbed girder segments all include a bottom plate whose longitudinal arc is consistent with the inner contour of the tunnel, and the bottom plate is fixed with several ribs and several transverse diaphragms along the arc trajectory, and the bottom plate, ribs and transverse diaphragm The interior of the slab is equipped with a reinforced skeleton, and the ribs and diaphragms are located inside the bottom formwork.

Preferably, several round holes are provided at the bottom of the ribs for piercing through the steel bars; the outer steel mesh of the secondary lining and the inside of the bottom form are poured with ordinary concrete layers.

Preferably, grouting holes are provided on the side of the bottom form.

A construction method for the secondary lining of the tunnel using the prefabricated UHPC structure as the bottom form, which is carried out according to the following steps: (1) According to the actual site conditions and process requirements, the cross section of the tunnel support structure is divided into four parts, including the left wall segment, right side wall segment, vault segment and invert; (2) after full section excavation, cast-in-place construction or prefabricated hoisting invert; For the reinforced skeleton of the clapboard, pour the concrete of the UHPC rib beam segment; (4) Bind the outer reinforcement mesh of the secondary lining of the tunnel; Mechanical assembly; (6) The left and right wall segments are assembled to the left and right ends of the inverted arch; (7) The vault segment is hung and assembled to the left and right wall segments. A prefabricated UHPC structure is formed on the legs one after another along the longitudinal direction of the tunnel; (8) The joints of the left wall segment, right wall segment, vault segment and inverted arch need to be connected with anchor rods, and the joints A waterproof gasket is required; (9) The prefabricated UHPC structure is used as the bottom form, and the ordinary concrete is poured in place to form the secondary lining of the tunnel, and the construction is completed.

Compared with the prior art, the present invention has the following beneficial effects: give full play to the ultra-high compressive strength, high crack resistance, impermeability and freeze-thaw resistance of UHPC, and the performance of high durability, the size of the prefabricated segmental components The accuracy and quality can be guaranteed; the mechanized assembly in the hole can shorten the construction period and improve the working conditions; after the assembly into a ring, it can be used as a non-removable formwork for pouring concrete, and bear the weight of grouting and cast-in-place concrete, reducing the binding work of the inner cavity steel skeleton The amount, saving a lot of support material and labor. At the same time, the invention has simple structure, reasonable design and convenient construction, can be widely used in tunnel structures, and improves construction efficiency and service life.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic elevational view of a fabricated UHPC structure according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of the secondary lining of the tunnel according to the embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

As shown in Figures 1 and 2, this embodiment provides a tunnel secondary lining with a prefabricated UHPC structure as the bottom form, including the left wall segment 1, the right wall segment 2 and the arch The UHPC ribbed beam segment 100 of the top segment 3 forms a prefabricated UHPC structure 200 as a whole, which is used as the bottom formwork for the secondary lining of the tunnel, and the inside of the bottom formwork is integrated with the external reinforcement mesh 21 of the secondary lining. The prefabricated UHPC structure not only acts as a demolition-free base form for the cast-in-situ concrete of the secondary lining of the tunnel, but also participates in the stress of the secondary lining. The structure is simple, the design is reasonable, and the construction is convenient, which can shorten the construction period, save construction support materials, improve working conditions, and can be widely used in tunnel structures to improve construction efficiency and service life.

In the embodiment of the present invention, the UHPC rib beam segments of the left wall segment and the right wall segment are respectively assembled to the left and right ends of the invert 4, and the invert is a prefabricated or cast-in-place reinforced concrete structure.

In the embodiment of the present invention, the UHPC rib beam segment of the vault segment is suspended and assembled to the UHPC rib beam segment corbels of the left wall segment and the right wall segment to form a ring along the longitudinal direction of the tunnel. A prefabricated UHPC structure connected to a ring.

In the embodiment of the present invention, the joints of the UHPC rib beam segments and the inverted arches of the left wall segment and the right wall segment need to be connected with anchor rods 5, and the joints of adjacent UHPC rib beam segments need to be connected with Anchor rods are connected, and all joints are provided with waterproof gaskets 18.

In the embodiment of the present invention, the UHPC ribbed girder sections all include a bottom plate 11 whose longitudinal arc is consistent with the inner contour of the tunnel, and the bottom plate is fixed with several ribs 12 and several transverse diaphragms 13 along the arc trajectory. The interior of the bottom plate, the ribs and the diaphragm are all equipped with a reinforced skeleton 14, and the ribs and the diaphragm are all located inside the bottom form.

In the embodiment of the present invention, several round holes 15 are provided at the bottom of the ribs for piercing the steel bars 16; the outer steel mesh of the secondary lining and the inside of the bottom form are poured with ordinary concrete layers 22 .

In the embodiment of the present invention, a grouting hole 17 is provided on the side of the bottom form.

A construction method for the secondary lining of the tunnel using the prefabricated UHPC structure as the bottom form, which is carried out according to the following steps: (1) According to the actual site conditions and process requirements, the cross section of the tunnel support structure is divided into four parts, including the left wall segment, right side wall segment, vault segment and invert; (2) after full section excavation, cast-in-place construction or prefabricated hoisting invert; For the reinforced skeleton of the clapboard, pour the concrete of the UHPC rib beam segment; (4) Bind the outer reinforcement mesh of the secondary lining of the tunnel; Mechanical assembly; (6) The left and right wall segments are assembled to the left and right ends of the inverted arch; (7) The vault segment is hung and assembled to the left and right wall segments. A prefabricated UHPC structure is formed on the legs one after another along the longitudinal direction of the tunnel; (8) The joints of the left wall segment, right wall segment, vault segment and inverted arch need to be connected with anchor rods, and the joints A waterproof gasket is required; (9) The prefabricated UHPC structure is used as the bottom form, and the ordinary concrete is poured in place to form the secondary lining of the tunnel, and the construction is completed.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or modify the equivalent of equivalent changes. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (4)

1. A tunnel secondary lining with a prefabricated UHPC structure as the base form, characterized in that: it includes UHPC rib beam sections assembled respectively on the left side wall section, the right side wall section and the vault section of the tunnel tunnel Section, forming a prefabricated UHPC structure as a whole, as the bottom formwork of the secondary lining of the tunnel, the inside of the bottom formwork is integrated with the outer reinforcement mesh of the secondary lining; the UHPC rib beam section of the vault section is suspended and assembled to the left wall On the UHPC rib beam section corbels of the segmental and right wall segments, a prefabricated UHPC structure is formed ring by ring along the longitudinal direction of the tunnel; the UHPC ribs of the left wall segment and right wall segment The joints between beam segments and inverted arches need to be connected with bolts, and the joints between adjacent UHPC rib beam segments need to be connected with anchor rods, and waterproof gaskets are installed at all joints; UHPC rib beam segments include longitudinal arcs. The bottom plate has a line consistent with the inner contour of the tunnel. The bottom plate is fixed with several ribs and several transverse diaphragms along its arc trajectory. The plates are all located inside the bottom form; the bottom of the ribs are provided with a number of round holes for piercing the reinforcing bars. 2. The secondary lining of the tunnel with the prefabricated UHPC structure as the bottom form according to claim 1, characterized in that: the UHPC rib beam segments of the left wall segment and the right wall segment are respectively assembled to the inverted arch At the left and right ends, the inverted arches are prefabricated or cast-in-place reinforced concrete structures. 3. The secondary lining of the tunnel with the prefabricated UHPC structure as the bottom form according to claim 1, characterized in that: the side of the bottom form is provided with grouting holes. 4. A construction method for the secondary lining of the tunnel with the prefabricated UHPC structure as the bottom form according to any one of claims 1-3, characterized in that, the following steps are carried out: (1) according to the actual site conditions and the process Requirements, the cross-section of the tunnel support structure is divided into four parts, including the left wall segment, right wall segment, vault segment and inverted arch; (2) After the full-section excavation, cast-in-place construction or prefabricated hoisting inverted arch; (3) Bind the reinforced skeleton of the bottom plate, ribs and diaphragm of the UHPC rib beam section, and pour concrete for the UHPC rib beam section; (4) Bind the outer steel mesh of the secondary lining of the tunnel; After the rib beam sections are cured to reach strength, they are transported into the tunnel and assembled by machinery; (6) The left wall section and the right wall section are assembled to the left and right ends of the inverted arch; (7) The vault section The segments are hung and assembled to the corbels of the left wall segment and the right wall segment to form a prefabricated UHPC structure that is connected one by one along the longitudinal direction of the tunnel; (8) the left wall segment, the right wall segment, The joint between the vault segment and the inverted arch needs to be connected with bolts, and waterproof gaskets must be provided at the joint; (9) The prefabricated UHPC structure is used as the bottom form, and the ordinary concrete is cast in place to form the secondary lining of the tunnel, and the construction is completed.

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