Prestressed lining structure and construction method for underground gas storage

Abstract

The present invention discloses a prestressed lining structure and construction method for an underground gas storage reservoir, which relates to the technical field of underground gas storage and includes: a lining layer, which is cast by concrete and has built-in prestressed steel bars; a sealing layer is arranged on the inner side of the lining layer and defines a gas storage chamber; and a sliding layer is arranged between the lining layer and the sealing layer. The provision of prestressed steel bars can offset part of the internal pressure of the gas storage reservoir, thereby alleviating the problem of concrete cracking. The lining layer is divided into a first lining layer and a second lining layer, and tensioning grooves are reserved at the bottom of the first lining layer. The tensioning grooves provide 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 cast in the tensioning grooves to ensure the integrity of the lining layer. After the sealing layer is constructed, grouting is injected into the gap between the lining layer and the sliding layer to ensure that the grouting is dense and complete, reduce stress concentration, and further alleviate the problem of concrete cracking.

Description

Technical Field

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

[0002] Underground gas storage excavates underground space in the underground hard rock layer, constructs a reinforced concrete structure inside to form a sealed lining structure, uses the surrounding rock to bear the pressure of the compressed air, and the lining structure plays the role of sealing and transferring the load.

[0003] Underground gas storage has a large internal pressure. Long-term use will cause cracks in the lining structure, affecting load transfer and sealing performance.

[0004] In view of this, how to provide an underground gas storage that avoids cracking of the lining structure is a problem that technical personnel in this field urgently need to solve. Summary of the Invention

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

[0006] To achieve the above-mentioned object, the present invention provides a prestressed lining structure for an underground gas storage, comprising:

[0007] The lining layer is made of concrete and has prestressed steel bars built into it;

[0008] a sealing layer, disposed on the inner side of the lining layer and defining an air storage chamber;

[0009] The slip layer is arranged between the lining layer and the sealing layer.

[0010] Furthermore, the slip layer is adhered to the sealing layer or sprayed on the sealing layer.

[0011] Furthermore, the lining layer includes:

[0012] The first lining layer has a bottom inner surface that is concave downward to form a tensioning notch;

[0013] The second lining layer is arranged in the tensioning notch and connected with the first lining layer.

[0014] Furthermore, 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 slip layer includes a first slip layer corresponding to the first lining layer and a second slip layer corresponding to the second lining layer.

[0015] Furthermore, 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 bar extends into the tensioning groove.

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

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

[0019] S2: Laminating the first sliding layer and the first sealing layer, and arranging them on the first lining layer accordingly;

[0020] S3: tensioning prestressed steel bars in the tensioning grooves, and pouring concrete into the tensioning grooves after tensioning to form a second lining layer connected to the first lining layer. The first lining layer and the second lining layer constitute a lining layer;

[0021] S4: Laminating the second sliding layer and the second sealing layer and arranging them correspondingly on the second lining layer, splicing the first sliding layer and the second sliding layer, welding the first sealing layer and the second sealing layer, the first sliding layer and the second sliding layer forming a sliding layer, and the first sealing layer and the second sealing layer forming a sealing layer.

[0022] Furthermore, a grouting pipe is arranged on the top of the first lining layer and fixed to the steel bar; after the first sealing layer and the second sealing layer are welded, a gap is formed between the lining layer and the sliding layer, the grouting pipe is connected to the gap, and grouting is injected into the gap through the grouting pipe.

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

[0024] Furthermore, in step S1, a slot template box is provided below the template at a position corresponding to the tensioning slot.

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

[0026] 1. The lining layer is made of poured concrete with built-in prestressed steel bars. The setting of prestressed steel bars can offset part of the internal pressure of the gas storage reservoir, thereby alleviating the problem of concrete cracking.

[0027] 2. During the lining construction process, the lining layer is divided into the first lining layer and the second lining layer. A tensioning groove is reserved at the bottom of the first lining layer. The tensioning groove 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 cast in the tensioning groove to ensure the integrity of the lining layer.

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

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

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

[0031] Figure 2 This is an enlarged schematic diagram of the structure at the tensioning notch;

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

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

[0034] Among them, 1. First lining layer; 2. First sliding layer; 3. First sealing layer; 4. Second lining layer; 5. Second sliding layer; 6. Second sealing layer; 7. Gap; 8. Grouting pipe; 9. Anchor; 10. Prestressed steel bar; 11. First weld; 12. Second weld. DETAILED DESCRIPTION

[0035] Among the prior arts that have been searched:

[0036] Chinese patent application number 202411920996.8 discloses a prestressed, high-pressure gas storage container with a damped, segmented lining. From the inside out, it consists of a steel lining, lining blocks, a buffer layer, and a concrete layer. The steel lining and buffer layer are capsule-shaped, with the lining blocks enclosing a circular column. Individual lining blocks are reinforced concrete, with gaps between adjacent lining blocks. Self-resetting dampers are installed on the circumferential joint surfaces of adjacent lining blocks. Prestressed tendons are embedded within the concrete layer. The first tendon is located in the middle of the concrete layer, with several of the first tendons spaced equidistantly around the circumference. A second tendon is radially located at the end of the concrete layer. A third tendon is axially arranged throughout the capsule structure, with anchor ribs at each end. This structure significantly reduces the thickness of the steel lining while also being able to withstand higher internal pressures, resulting in a more balanced gas storage container.

[0037] Another patent, CN202410375595.2, discloses a composite-lined gas storage cavern structure, comprising a gas storage cavern body, and a sealing layer lining and a main lining arranged in sequence from the inside to the outside of the gas storage cavern body. The main lining is formed by at least two arc-shaped segments connected end to end, and a joint is provided between adjacent segments. The gas storage cavern structure also includes a secondary lining arranged between the main lining and the sealing layer lining to constrain the segments. The secondary lining adopts an integral structure. The sealing layer lining is fitted on the inner surface of the secondary lining. The sealing layer lining can be made of a flexible sealing material or a steel plate.

[0038] Of the two patents mentioned above, the Chinese patent with 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 application number CN202410375595.2 discloses a main and secondary lining structure to increase the service life of the sealing layer, but its feasibility is not ideal.

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

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

[0042] The lining layer is made of concrete and has prestressed steel bars 10 built in;

[0043] a sealing layer, disposed on the inner side of the lining layer and defining an air storage chamber;

[0044] The slip layer is arranged between the lining layer and the sealing layer.

[0045] In this embodiment, the slip layer is adhered to the sealing layer or sprayed on the sealing layer.

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

[0047] The first lining layer 1 has an inner bottom surface that is concave downward to form a tensioning notch;

[0048] The second lining layer 4 is arranged in the tensioning notch and connected with 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 slip layer includes a first slip layer 2 corresponding to the first lining layer 1 and a second slip 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 slip layer 2 and the second slip layer 5 are spliced.

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

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

[0053] S1: Arrange the formwork for the first lining layer 1 on the inner surface of the chamber, set a notch formwork box at the position corresponding to the tensioning notch below the formwork to form the tensioning notch, arrange steel bars in the formwork, fix the prestressed steel bars 10 to the steel bars, place the tensioning ends of the prestressed steel bars 10 into the tensioning notch, and pour concrete into the formwork to form the first lining layer 1;

[0054] S2: Laminating the first sliding layer 2 and the first sealing layer 3 and arranging them on the first lining layer 1 accordingly;

[0055] S3: tensioning the prestressed steel bars 10 in the tensioning grooves, anchoring them with anchors 9 after tensioning, and pouring concrete into the tensioning grooves to form a second lining layer 4 connected to the first lining layer 1. The first lining layer 1 and the second lining layer 4 constitute a lining layer;

[0056] S4: The second slip layer 5 and the second sealing layer 6 are laminated and arranged correspondingly on the second lining layer 4. The first slip layer 2 and the second slip layer 5 are spliced. The first sealing layer 3 and the second sealing layer 6 are welded to form a first weld 11. The first slip layer 2 and the second slip layer 5 constitute a slip layer, and the first sealing layer 3 and the second sealing layer 6 constitute a sealing layer.

[0057] In this embodiment, a grouting pipe 8 is arranged on the top of the first lining layer 1 and fixed to the steel bar; 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, and the grouting pipe 8 is connected to the gap 7, and grouting is injected into the gap 7 through the grouting pipe 8.

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

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

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

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying 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 therefore cannot be understood as a limitation on the present invention.

[0062] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A prestressed lining structure for an underground gas storage, characterized in that: include: The lining layer is made of concrete and has prestressed steel bars (10) built into it; a sealing layer, disposed on the inner side of the lining layer and defining an air storage chamber; a slip layer, disposed between the lining layer and the sealing layer; The lining layer comprises: A first lining layer (1), the bottom inner surface of which is concave downward to form a tensioning notch; a second lining layer (4) disposed in the tensioning notch and connected to the first lining layer (1); 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 slip layer comprises a first slip layer (2) corresponding to the first lining layer (1) and a second slip layer (5) corresponding to the second lining layer (4); the first sealing layer (3) and the second sealing layer (6) are welded, and the first slip layer (2) and the second slip layer (5) are spliced.

2. The prestressed lining structure of an underground gas storage reservoir according to claim 1, characterized in that: The slip layer is adhered to the sealing layer or sprayed on the sealing layer.

3. The prestressed lining structure of an underground gas storage reservoir according to claim 1, characterized in that: The tensioning end of the prestressed steel bar (10) extends into the tensioning slot.

4. A construction method for a prestressed lining structure of an underground gas storage reservoir, characterized in that: The following steps are involved: S1: Arranging a template for the first lining layer (1) on the inner surface of the chamber, reserving a tensioning notch below the template, arranging steel bars in the template, fixing prestressed steel bars (10) to the steel bars, placing the tensioning ends of the prestressed steel bars (10) in the tensioning notch, and pouring concrete into the template to form the first lining layer (1); S2: Laminating the first sliding layer (2) and the first sealing layer (3), and arranging them correspondingly on the first lining layer (1); S3: tensioning prestressed steel bars (10) in the tensioning slot, and after tensioning, pouring concrete into the tensioning slot to form a second lining layer (4) connected to the first lining layer (1), the first lining layer (1) and the second lining layer (4) forming a lining layer; S4: The second slip layer (5) and the second sealing layer (6) are bonded and arranged correspondingly on the second lining layer (4), the first slip layer (2) and the second slip layer (5) are spliced, the first sealing layer (3) and the second sealing layer (6) are welded, the first slip layer (2) and the second slip layer (5) form a slip layer, and the first sealing layer (3) and the second sealing layer (6) form a sealing layer.

5. The construction method of a prestressed lining structure for an underground gas storage according to claim 4, characterized in that: A grouting pipe (8) is arranged on the top of the first lining layer (1), and the grouting pipe (8) is fixed to the steel bar; 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 pipe (8) is communicated with the gap (7), and grouting is injected into the gap (7) through the grouting pipe (8).

6. The construction method of a prestressed lining structure for an underground gas storage according to claim 5, characterized in that: The sliding layer and the sealing layer are arranged in multiple groups along the length direction of the lining layer, and two adjacent groups of sealing layers are welded. The grouting pipe (8) is provided with multiple grouting outlets corresponding to the multiple groups of sealing layers.

7. The construction method of a prestressed lining structure for an underground gas storage according to claim 4, characterized in that: In step S1, a slot template box is provided below the template at a position corresponding to the tensioning slot.

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