Underground gas storage prestress lining structure and construction method

Abstract

The invention discloses an underground gas storage prestress lining structure and a construction method, and relates to the technical field of underground gas storage, the underground gas storage prestress lining structure comprises a lining layer formed by concrete pouring and internally provided with prestress steel bars; the sealing layer is arranged on the inner side of the lining layer and defines a gas storage chamber; the sliding layer is arranged between the lining layer and the sealing layer. The arrangement of the prestressed reinforcements can counteract part of internal pressure of the gas storage, so that the problem of concrete cracking is relieved. The lining layer is divided into the first lining layer and the second lining layer, the tensioning notch is reserved in the bottom of the first lining layer and provides sufficient tensioning space for the prestressed steel bars, the tensioning effect of the prestressed steel bars is ensured, the second lining layer is formed in the tensioning notch in a pouring mode after the prestressed steel bars are tensioned, and the integrity of the lining layer is ensured. After the sealing layer is constructed, grouting is conducted on the gap between the lining layer and the sliding layer, it is guaranteed that grouting is compact and complete, stress concentration is reduced, and the problem of concrete cracking is further relieved.

Description

Technical Field

[0001] The present invention relates to the technical field of underground gas storage, and particularly to a prestressed lining structure and construction method for an underground gas storage. Background Art

[0002] An underground gas storage excavates an underground space in hard underground rock, constructs a reinforced concrete structure on the inner side to form a sealed lining structure, and utilizes the surrounding rock to bear the pressure of compressed air, while the lining structure plays a role in sealing and transmitting loads.

[0003] The underground gas storage has a relatively large internal pressure, and long-term use will cause the lining structure to crack, affecting load transmission and sealing performance.

[0004] In view of this, how to provide an underground gas storage that avoids cracking of the lining structure is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a prestressed lining structure and construction method for an underground gas storage to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the present invention provides a prestressed lining structure for an underground gas storage, including:

[0007] A lining layer, which is formed by pouring concrete and is internally provided with prestressed steel bars;

[0008] A sealing layer, which is arranged on the inner side of the lining layer and defines a gas storage chamber;

[0009] A sliding layer, which is arranged between the lining layer and the sealing layer.

[0010] Further, the sliding layer is pasted or sprayed on the sealing layer.

[0011] Further, the lining layer includes:

[0012] A first lining layer, the inner surface of the bottom of which is recessed downward to form a tension notch;

[0013] A second lining layer, which is arranged in the tension notch and is connected with the first lining layer.

[0014] Further, the sealing layer includes a first sealing layer corresponding to the first lining layer and a second sealing layer corresponding to the second lining layer; the sliding layer includes a first sliding layer corresponding to the first lining layer and a second sliding layer corresponding to the second lining layer.

[0015] Further, the first sealing layer and the second sealing layer are welded, and the first sliding layer and the second sliding layer are spliced.

[0016] Furthermore, the tensioning end of the prestressed steel bars extends into the tensioning notch.

[0017] The present invention also provides a construction method for a prestressed lining structure of an underground gas storage, comprising the following steps:

[0018] S1: Arrange the formwork of the first lining layer on the inner surface of the chamber, reserve a tensioning notch below the formwork, arrange steel bars in the formwork, fix the prestressed steel bars to the steel bars, place the tensioning end of the prestressed steel bars into the tensioning notch, and pour concrete into the formwork to form the first lining layer;

[0019] S2: Fit the first sliding layer and the first sealing layer together and arrange them correspondingly on the first lining layer;

[0020] S3: Tension the prestressed steel bars in the tensioning notch, and after the tensioning is completed, pour concrete into the tensioning notch to form a second lining layer connecting with the first lining layer. The first lining layer and the second lining layer form the lining layer;

[0021] S4: Fit the second sliding layer and the second sealing layer together and arrange them correspondingly on the second lining layer. The first sliding layer and the second sliding layer are spliced, the first sealing layer and the second sealing layer are welded. The first sliding layer and the second sliding layer form the sliding layer, and the first sealing layer and the second sealing layer form the sealing layer.

[0022] Furthermore, arrange grouting pipes at the top of the first lining layer and fix the grouting pipes to the steel bars; after the first sealing layer and the second sealing layer are welded, a void is formed between the lining layer and the sliding layer. The grouting pipes communicate with the void, and grout is injected into the void through the grouting pipes.

[0023] Furthermore, multiple groups of the sliding layer and the sealing layer are arranged along the length direction of the lining layer. Adjacent two groups of sealing layers are welded, and the grouting pipes are provided with multiple slurry outlets corresponding to the multiple groups of sealing layers.

[0024] Furthermore, in step S1, a notch formwork box is arranged at the position corresponding to the tensioning notch below the formwork.

[0025] The present invention discloses the following technical effects:

[0026] 1. The lining layer is formed by pouring concrete and is internally provided with prestressed steel bars. The setting of the prestressed steel bars can offset part of the internal pressure of the gas storage, thereby alleviating the problem of concrete cracking.

[0027] 2. During the construction process of the lining layer, the lining layer is divided into the first lining layer and the second lining layer. A tensioning notch is reserved at the bottom of the first lining layer. The tensioning notch provides sufficient tensioning space for the prestressed steel bars to ensure the tensioning effect of the prestressed steel bars. After the prestressed steel bars are tensioned, the second lining layer is formed by pouring in the tensioning notch to ensure the integrity of the lining layer.

[0028] 3. After the construction of the sealing layer, grout is injected into the gap between the lining layer and the sliding layer to ensure dense and complete grouting, reduce stress concentration, and further alleviate the problem of concrete cracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is a front view cross-sectional view of the present invention;

[0031] Figure 2 It is an enlarged schematic view of the structure at the tension notch;

[0032] Figure 3 It is an arrangement diagram of multiple second sealing layers in the length direction of the lining layer;

[0033] Figure 4 It is a welding schematic diagram between multiple sealing layers in the length direction of the lining layer;

[0034] Among them, 1, the first lining layer; 2, the first sliding layer; 3, the first sealing layer; 4, the second lining layer; 5, the second sliding layer; 6, the second sealing layer; 7, the gap; 8, the grouting pipe; 9, the anchor; 10, the prestressed steel bar; 11, the first weld; 12, the second weld. DETAILED DESCRIPTION OF THE INVENTION

[0035] In the prior art retrieved:

[0036] Chinese Patent with application number 202411920996.8 discloses a prestressed high-pressure gas storage structure with damped segmented lining, which from the inside to the outside consists of a steel lining, lining blocks, a buffer layer and a concrete layer in sequence. The steel lining and the buffer layer are in the shape of a capsule structure. Among them, the lining blocks enclose to form a circular column. Each single lining block is a reinforced concrete block, and there are gaps between adjacent lining blocks. A self-resetting damper is arranged on the circumferential joint surface between adjacent lining blocks; prestressed tendons are embedded in the concrete layer. The first prestressed tendon is arranged in the middle of the concrete layer, and several first prestressed tendons are arranged equidistantly along the circumferential direction; the second prestressed tendon is arranged radially at the end of the concrete layer; the third prestressed tendon is arranged axially and penetrates through the capsule structure, and anchoring ribs are arranged at both ends of the third prestressed tendon. This structure significantly reduces the thickness of the steel lining and can also withstand higher internal pressure, which is a gas storage container with more reasonable stress.

[0037] Another patent with the patent number CN202410375595.2 discloses a composite lining gas storage cavern structure, which includes a gas storage cavern body, and a sealing layer lining and a main lining arranged in the gas storage cavern body from inside to outside in sequence. The main lining is formed by enclosing at least two arc-shaped segments connected end to end in sequence, and there is a splicing joint between adjacent segments. The gas storage cavern structure also includes a secondary lining arranged between the main lining and the sealing layer lining to restrain the segments, and the secondary lining adopts an integral structure. The sealing layer lining is attached to the inner surface of the secondary lining. The sealing layer lining can adopt a flexible sealing material or a steel plate.

[0038] In the above two patents, the Chinese patent with the application number 202411920996.8 discloses a solution for controlling the cracking of the main lining by setting multiple layers of prestressed tendons in the lining and damping blocks inside. This patent is not easy to construct in actual projects; the Chinese patent with the patent number CN202410375595.2 discloses the main and secondary lining structures to improve the service life of the sealing layer, and the feasibility is not ideal.

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0041] The embodiment of the present invention provides a prestressed lining structure for an underground gas storage, including:

[0042] A lining layer, formed by pouring concrete, with prestressed steel bars 10 built in;

[0043] A sealing layer, arranged on the inner side of the lining layer and defining a gas storage chamber;

[0044] A sliding layer, arranged between the lining layer and the sealing layer.

[0045] In this embodiment, the sliding layer is pasted on the sealing layer or sprayed on the sealing layer.

[0046] In this embodiment, the lining layer includes:

[0047] The first lining layer 1, the inner surface of the bottom of which is recessed downward to form a tension notch;

[0048] The second lining layer 4, arranged in the tension notch and connected to the first lining layer 1.

[0049] In this embodiment, the sealing layer includes a first sealing layer 3 corresponding to the first lining layer 1 and a second sealing layer 6 corresponding to the second lining layer 4; the sliding layer includes a first sliding layer 2 corresponding to the first lining layer 1 and a second sliding layer 5 corresponding to the second lining layer 4.

[0050] In this embodiment, the first sealing layer 3 and the second sealing layer 6 are welded, and the first sliding layer 2 and the second sliding layer 5 are spliced.

[0051] In this embodiment, the tension end of the prestressed steel bar 10 extends into the tension notch.

[0052] The embodiment of the present invention also provides a construction method for a prestressed lining structure of an underground gas storage, including the following steps:

[0053] S1: Arrange the formwork of the first lining layer 1 on the inner surface of the chamber. A notch formwork box is provided at the position corresponding to the tension notch below the formwork for forming the tension notch. Reinforcement bars are arranged in the formwork, the prestressed steel bar 10 is fixed to the reinforcement bars, the tension end of the prestressed steel bar 10 is placed into the tension notch, and concrete is poured into the formwork to form the first lining layer 1;

[0054] S2: Fit the first sliding layer 2 and the first sealing layer 3 and arrange them correspondingly on the first lining layer 1;

[0055] S3: Tension the prestressed steel bar 10 in the tension notch. After the tensioning is completed, it is anchored by the anchor 9. Concrete is poured into the tension notch to form the second lining layer 4 connected to the first lining layer 1. The first lining layer 1 and the second lining layer 4 form the lining layer;

[0056] S4: Fit the second sliding layer 5 and the second sealing layer 6 and arrange them correspondingly on the second lining layer 4. The first sliding layer 2 and the second sliding layer 5 are spliced. The first sealing layer 3 and the second sealing layer 6 are welded to form the first weld seam 11. The first sliding layer 2 and the second sliding layer 5 form the sliding layer, and the first sealing layer 3 and the second sealing layer 6 form the sealing layer.

[0057] In this embodiment, a grouting pipeline 8 is arranged at the top of the first lining layer 1 and fixed to the reinforcement bars; after the first sealing layer 3 and the second sealing layer 6 are welded, a gap 7 is formed between the lining layer and the sliding layer. The grouting pipeline 8 is communicated with the gap 7, and grout is injected into the gap 7 through the grouting pipeline 8.

[0058] As Figure 4 shown, in this embodiment, multiple groups of sliding layers and sealing layers are arranged along the length direction of the lining layer. Adjacent two groups of sealing layers are welded to form the second weld seam 12. The grouting pipeline 8 is provided with multiple slurry outlets corresponding to multiple groups of sealing layers.

[0059] As Figure 3As shown, in this embodiment, a plurality of tension notches are arranged along the length direction of the lining layer, and the tension notches are cast to form a plurality of second lining layers 4. The plurality of second lining layers 4 are arranged in a left-right cross pattern.

[0060] Through in-situ comparison experiments on-site, it is found that the critical pressure for concrete cracking corresponding to the lining structure disclosed in this embodiment is significantly greater than that of ordinary reinforced concrete linings, and as the prestress increases, the gas storage pressure that the lining layer can withstand also increases accordingly.

[0061] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0062] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A prestressed lining structure for an underground gas storage, characterized in that, Comprising: A lining layer, formed by pouring concrete and internally provided with prestressed steel bars (10); A sealing layer, arranged on the inner side of the lining layer and defining a gas storage chamber; A sliding layer, arranged between the lining layer and the sealing layer.

2. The prestressed lining structure of an underground gas storage cavern according to claim 1, wherein The sliding layer is pasted or sprayed on the sealing layer.

3. The prestressed lining structure of an underground gas storage according to claim 1, characterized in that, The lining layer comprises: A first lining layer (1), the inner surface of the bottom of which is recessed downward to form a tension notch; A second lining layer (4), arranged in the tension notch and connected with the first lining layer (1).

4. The prestressed lining structure of an underground gas storage according to claim 3, characterized in that The sealing layer comprises a first sealing layer (3) corresponding to the first lining layer (1) and a second sealing layer (6) corresponding to the second lining layer (4); the sliding layer comprises a first sliding layer (2) corresponding to the first lining layer (1) and a second sliding layer (5) corresponding to the second lining layer (4).

5. The prestressed lining structure of an underground gas storage as claimed in claim 4, wherein The first sealing layer (3) and the second sealing layer (6) are welded, and the first sliding layer (2) and the second sliding layer (5) are spliced.

6. The prestressed lining structure of an underground gas storage according to claim 3, characterized in that The tension end of the prestressed steel bar (10) extends into the tension notch.

7. A construction method for a prestressed lining structure of an underground gas storage, characterized in that, Comprising the following steps: S1: Arrange the formwork of the first lining layer (1) on the inner surface of the chamber, reserve a tension notch below the formwork, arrange steel bars in the formwork, fix the prestressed steel bars (10) to the steel bars, place the tension end of the prestressed steel bars (10) into the tension notch, and pour concrete into the formwork to form the first lining layer (1); S2: Fit the first sliding layer (2) with the first sealing layer (3) and arrange them correspondingly on the first lining layer (1); S3: Tension the prestressed steel bars (10) in the tension notch, and after the tensioning is completed, pour concrete into the tension notch to form a second lining layer (4) connected with the first lining layer (1), and the first lining layer (1) and the second lining layer (4) form the lining layer; S4: Fit the second sliding layer (5) with the second sealing layer (6) and arrange them correspondingly on the second lining layer (4), splice the first sliding layer (2) and the second sliding layer (5), weld the first sealing layer (3) and the second sealing layer (6), the first sliding layer (2) and the second sliding layer (5) form the sliding layer, and the first sealing layer (3) and the second sealing layer (6) form the sealing layer.

8. The construction method of a prestressed lining structure for an underground gas storage described in claim 7, characterized in that, Arrange a grouting pipeline (8) at the top of the first lining layer (1) and fix the grouting pipeline (8) to the steel bars; after the first sealing layer (3) and the second sealing layer (6) are welded, a gap (7) is formed between the lining layer and the sliding layer, the grouting pipeline (8) communicates with the gap (7), and grout is injected into the gap (7) through the grouting pipeline (8).

9. The construction method of a prestressed lining structure for an underground gas storage as claimed in claim 8, characterized in that, Multiple groups of the sliding layer and the sealing layer are arranged along the length direction of the lining layer, adjacent two groups of sealing layers are welded, and the grouting pipeline (8) is provided with a plurality of slurry outlets corresponding to the multiple groups of sealing layers.

10. The construction method of a prestressed lining structure for an underground gas storage according to claim 7, characterized in that, In step S1, a notch formwork box is arranged at the position corresponding to the tension notch below the formwork.

Images