CN218062324U

CN218062324U - Multilayer composite shield tunnel segment based on fiber concrete

Info

Publication number: CN218062324U
Application number: CN202222274805.8U
Authority: CN
Inventors: 张旭生; 方若全; 丁彩良; 张忆; 吴鑫林; 吴刚; 郭正兴; 管东芝; 吴胜男
Original assignee: Southeast University; China Railway Siyuan Survey and Design Group Co Ltd
Current assignee: Southeast University; China Railway Siyuan Survey and Design Group Co Ltd
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2022-12-16
Anticipated expiration: 2032-08-29

Abstract

The utility model provides a compound shield tunnel section of jurisdiction of multilayer based on fiber concrete. The duct piece comprises an ECC-NC inner protective layer, a duct piece structural layer and a UHPC outer protective layer. The ECC-NC inner protective layer is formed by embedding ECC building blocks in common concrete grids, the segment structure layer is made of common reinforced concrete, and the UHPC outer protective layer is made of basalt fiber grid sheets and ultra-high performance concrete. A bubble film groove type joint surface is formed between the ECC building block and the common concrete, and the joint surface between the UHPC outer protection layer and the duct piece structure layer consists of the bubble film groove type joint surface and a grid type joint surface. The duct piece is manufactured by a small amount of technological transformation such as reverse preparation of ECC building blocks, pasting of an air bubble film on an upper cover plate of a duct piece die and the like on the basis of a conventional preparation method. The utility model discloses fused the high anti impervious high durable and the good performance of ECC fire resistance antiknock of anti-cracking of UHPC, promoted the section of jurisdiction performance, reduce cost's influence, preparation simultaneously is simple, can well combine with conventional preparation technology, possesses the potentiality of scale popularization.

Description

Multilayer composite shield tunnel segment based on fiber concrete

Technical Field

The utility model relates to an underground works field, concretely relates to compound shield tunnel section of jurisdiction of multilayer of fibre concrete.

Background

With the increase of the development speed of infrastructure construction in China, the construction amount of the shield tunnel is continuously increased, and the engineering amount is rapidly increased. The shield tunnel segment body is the main lining material in the shield method construction process, and has great influence on the tunnel engineering forming and the later-stage operation quality.

At present, the section of the underwater shield tunnel in China is developing in large scale and deep position, and the problems of large burial depth, high water and soil pressure and the like brought along with the section of the underwater shield tunnel put higher requirements on the safety and the durability of a segment structure. In the production, construction and operation processes of the conventional concrete shield tunnel segment, diseases such as cracking and damage are easy to occur, and the stress performance and the durability after tunnel forming can be greatly influenced. In case of fire or explosion and other accidents in the operation stage of the tunnel, the conventional concrete is easy to rapidly deteriorate in performance, so that the safety of the tunnel is rapidly reduced, and irreversible damage is caused.

With the progress of building material technology, fiber reinforced cement-based composite materials have been developed greatly. The incorporation of fibers plays a critical role in improving the toughness of cementitious materials. The research finds that the fiber reinforced cement-based composite material is a high-performance material with high toughness, high ductility, excellent tensile property and excellent crack control capability. Because the nature difference of ordinary fiber concrete is huge, adopt same kind of fiber concrete often can't improve all performance demands of section of jurisdiction simultaneously in shield tunnel section of jurisdiction, bring the cost and improve by a wide margin simultaneously. Therefore, single fiber concrete duct pieces are also relatively few in practical applications.

SUMMERY OF THE UTILITY MODEL

For solving the technical problem who exists, the utility model provides a compound shield tunnel section of jurisdiction of multilayer based on fiber concrete effectively improves tunnel durability, impervious performance, anti cracking performance, antiknock performance, crashproof performance, and the durability is good, and the cost is controllable simultaneously.

In order to realize the technical purpose, the utility model adopts the following technical scheme:

a composite shield tunnel section of jurisdiction of multilayer based on fiber concrete, include: the outer protective layer comprises an ECC-NC inner protective layer, a segment structural layer and a UHPC outer protective layer;

the ECC-NC inner protection layer is positioned on the lower surface of the whole multilayer composite shield tunnel segment and consists of ECC building blocks and a common concrete grid layer;

the common concrete grid layer consists of transverse and longitudinal concrete ribs and is fully distributed on the lower surface of the multilayer composite shield tunnel segment;

the ECC building blocks are fixedly embedded in the grid positions of the common concrete grid layer; the ECC building block is composed of a fiber cement-based composite material and construction ribs, the construction ribs are arranged in the ECC building block in a grid shape, upward 90-degree hooks are arranged at two ends of the construction ribs, and the construction ribs extend out of the side face of the ECC building block; the extending parts of the construction ribs of the adjacent ECC building blocks are mutually overlapped; the upper surface and the side surface of the ECC block are provided with a first bubble film groove type interface, and the joint surface of the ECC block and the common concrete grid layer is a bubble film groove type joint surface;

the UHPC outer protective layer is made of an ultra-high performance concrete material and an arc basalt fiber mesh sheet;

the joint surface between the UHPC outer protective layer and the duct piece structural layer consists of a bubble film groove joint surface and a grid joint surface,

the groove-type joint surface of the bubble film is positioned in the two side areas of the multilayer composite shield tunnel segment in the arc length direction,

the grid type joint surface is positioned in the middle area of the multi-layer composite shield tunnel segment in the arc length direction.

The duct piece structural layer is made of polypropylene fiber common concrete and a ribbed steel reinforcement cage, and the diameter of the groove type joint surface of the bubble film is larger than the minimum aggregate particle size of the concrete of the duct piece structural layer.

And the thickness of the structural layer of the duct piece is obtained by subtracting the thickness of the UHPC outer protective layer from the thickness calculated according to the stress requirement.

The ECC building block is a cuboid structure with the length of 400mm, the width of 200mm and the height of 50mm.

The thickness of the UHPC outer protective layer is 50mm.

Has the advantages that:

(1) The utility model discloses a compound shield tunnel section of jurisdiction of multilayer combines different performance fiber concrete together, and the differentiation is arranged, and the surface realizes high anti-permeability high durability that splits through the UHPC layer, and the prefabricated ECC block is arranged on the internal surface layer, and the inside fibre of accessible gasifies the heat absorption rapidly under the conflagration to form slight space release stress, slight space here indicates that the inside fiber material of ECC block gasifies the back and forms, thereby protection section of jurisdiction structural layer, makes fire-resistant antiknock performance promote by a wide margin.

(2) The utility model discloses middle structure stress layer still mainly adopts the ordinary concrete of polypropylene fibre, and cost influence is less, and based on ripe section of jurisdiction manufacturing process, the improvement of carrying out a small amount of technologies can realize high-efficient manufacturing simultaneously, has economic competitiveness.

The air bubble film groove type and grid type joint surfaces are adopted to connect different layers of fiber concrete, the performance is reliable, two joint surface forms are comprehensively used, the effective joint area between the common concrete and the UHPC is greatly increased, the joint strength is high, and the overall performance of the composite shield tunnel segment is greatly improved. Meanwhile, the effective combination of two different concretes can greatly utilize the performance of UHPC, and improve the impermeability, crack resistance and durability of the shield tunnel segment.

Drawings

Fig. 1 is a schematic structural view of a fiber concrete based multi-layer composite shield tunnel segment;

fig. 2 is a bottom schematic view of a fiber concrete based multi-layer composite shield tunnel segment;

FIG. 3 is a schematic view of an ECC block connection;

FIG. 4 is a schematic view of an ECC block form;

fig. 5 is a schematic cross-sectional view of a fiber concrete based multi-layer composite shield tunnel segment;

FIG. 6 is a bottom view of the cover plate of the rigid form;

FIG. 7 is a schematic view of an NC-UHPC interface layer.

Wherein, 1 is an ECC-NC inner protection layer; 2, a segment structural layer; 3 is an UHPC outer protective layer; 4 is an ECC building block; 5 is a common concrete grid layer; 6 is a construction rib; 7 is a first bubble film groove type interface; 8 is a first bubble film; 9 is a ribbed reinforcement cage; 10 is an arc basalt fiber mesh sheet; 11 is a second bubble film; 12 is a second bubble film groove type interface; 13 is a grid interface.

Detailed Description

The technical solution of the present invention is described in detail below with reference to the schematic drawings, but the scope of protection of the present invention is not limited to the examples.

A multi-layer composite shield tunnel segment based on fiber concrete is shown in figure 1 and comprises an ECC-NC inner protective layer 1, a segment structural layer 2 and an UHPC outer protective layer 3.

As shown in figure 2, in the ECC-NC inner protection layer 1, the ECC building blocks 4 are embedded in the grid positions of the common concrete grid layer 5 at intervals of 100 mm.

As shown in fig. 3, the ECC block 4 is composed of a fiber cement-based composite (ECC) and construction ribs 6 arranged in a grid pattern in the ECC block, with upward 90 ° hooks provided at both ends and extending out of the side of the ECC block. The upper surface and the side surface of each ECC block are provided with a first bubble film groove type interface 7, and the extending parts of the construction ribs of the adjacent ECC blocks are mutually overlapped.

As shown in fig. 4, a first bubble film 8 is pasted inside the ECC block template, and the diameter of the first bubble film is larger than the minimum aggregate particle size of the concrete of the segment structure layer.

As shown in fig. 5, the segment structural layer 2 is made of polypropylene fiber common concrete and a ribbed steel reinforcement cage 9. The UHPC outer protective layer 3 is made of an ultra-high performance concrete material (UHPC) and an arc basalt fiber mesh sheet 10.

As shown in fig. 6, a second bubble film groove type interface 12 between the segment structure layer 2 and the UHPC outer protective layer 1 is formed by adhering a second bubble film 11 to the lower surface of the shield tunnel segment steel die top cover plate, and the diameter of the second bubble film is larger than the minimum aggregate particle size of the segment structure layer concrete.

As shown in fig. 7, a second bubble film groove interface 12 and a grid interface 13 are used between the segment structural layer 2 and the UHPC outer protective layer 1.

The preparation method of the multilayer composite shield tunnel segment based on the fiber concrete comprises the following steps:

the utility model further discloses a compound shield tunnel section of jurisdiction preparation method of multilayer based on fiber concrete, including following step:

firstly, manufacturing an ECC block template, and pasting a first bubble film in the ECC block template to form a groove-type interface of the first bubble film on the upper surface and the side surface of the ECC block;

reversely arranging the construction ribs to enable the end part hook direction to be downward; pouring a fiber cement-based composite material; removing the mold after curing and hardening to form the ECC building block placed reversely; forward shelving the ECC building block for storage;

step three, the ECC blocks are uniformly distributed on the whole cambered surface at the bottom of the shield tunnel segment steel mould, a certain gap is reserved between the ECC blocks to form a concrete grid structure, and the bonding performance between two types of concrete is improved;

the structural ribs are mutually overlapped;

step four, placing the ribbed reinforcement cage on the ECC building block;

step five: adhering a second bubble film on the lower surface of the cover plate at the top of the shield tunnel segment steel mould, and then covering the cover plate;

step six: pouring polypropylene fiber common concrete into the steel mould, vibrating, and primarily trowelling the exposed part of the upper surface; galling the exposed part of the upper surface in the transverse and longitudinal directions to form the grid interface; then, maintaining;

step seven: after the polypropylene fiber common concrete is initially set, opening the cover plate, forming a second bubble film groove type interface at the contact part of the upper surface of the duct piece and the duct piece, arranging the arc basalt fiber grid piece at the upper part, and smearing UHPC concrete to form an UHPC outer protective layer;

step eight: and curing by adopting a steam curing method, and forming the fiber concrete-based multilayer composite shield tunnel segment after the fiber concrete-based multilayer composite shield tunnel segment is completely hardened.

Further, in the third step, a certain gap of 100mm width is reserved between the ECC blocks.

Claims

1. The utility model provides a compound shield tunnel section of jurisdiction of multilayer based on fiber concrete which characterized in that includes: the outer protective layer comprises an ECC-NC inner protective layer, a segment structural layer and an UHPC outer protective layer;

the joint surface between the UHPC outer protective layer and the segment structural layer consists of a bubble film groove joint surface and a grid joint surface,

the grid joint surface is positioned in the middle area of the multi-layer composite shield tunnel segment in the arc length direction.

2. The fiber concrete based multilayer composite shield tunnel segment of claim 1, wherein: the duct piece structural layer is made of polypropylene fiber common concrete and a ribbed steel reinforcement cage, and the diameter of the groove type joint surface of the bubble film is larger than the minimum aggregate particle size of the concrete of the duct piece structural layer.

3. The fiber concrete based multilayer composite shield tunnel segment of claim 1, wherein: the thickness of the structural layer of the duct piece is the thickness calculated according to the stress requirement minus the thickness of the UHPC outer protective layer.

4. The fiber concrete based multilayer composite shield tunnel segment of claim 1, wherein: the ECC building block is a cuboid structure with the length of 400mm, the width of 200mm and the height of 50mm.

5. The fiber concrete based multilayer composite shield tunnel segment of claim 1, wherein: the thickness of the UHPC outer protective layer is 50mm.