City gate opening type tunnel lining structure

Abstract

The utility model provides a city gate opening type tunnel lining structure which comprises two surrounding rock bottom corner areas symmetrically trimmed at the bottom of a tunnel surrounding rock layer, and first lining layers are arranged on the wall faces, attached to a tunnel, of the tops of the two surrounding rock bottom corner areas. A second lining layer is arranged between the two surrounding rock base angle areas; anchoring parts are arranged on the surrounding rock bottom corner area, the second lining layer and the first lining layer, and the anchoring parts are fixed in a tunnel surrounding rock layer. According to the lining structure, the construction amount is reduced, the supporting mode that surrounding rock is connected with the lining is reserved, the bearing capacity of bed rock with the good integrity at the inverted arch position is fully utilized, waste caused by the fact that a large amount of bed rock is excavated out and a reinforced concrete inverted arch is additionally constructed is avoided, the engineering amount of secondary excavation is greatly reduced, the concrete amount of secondary lining is also saved, and the construction cost is reduced. And the construction cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of engineering construction technology, specifically to a tunnel lining structure of the city gate type. Background Technology

[0002] With the development of the national economy and the booming development of the construction industry, my country's transportation infrastructure construction has entered a new era after entering the 21st century. More and more high-standard railways and highways are being built. At the same time, my country is one of the countries with the widest distribution of karst in the world. In particular, in some mountainous areas, soluble rock strata such as limestone are widely distributed, with varying scales, shapes, sizes and locations. In the process of transportation infrastructure construction, some areas with more complex terrain are often traversed by tunnels, which inevitably leads to a large number of tunnel projects that cross various types of rock strata.

[0003] Currently, most transportation infrastructure projects traversing mountainous areas adopt the traditional fully cast-in-place construction method. This involves pouring a layer of steel bars and concrete onto the outer wall of an excavated tunnel to form a passable passage. While this method can complete the construction of transportation infrastructure, it requires a large amount of materials, resulting in high costs and intense construction. Utility Model Content

[0004] To address the issues of high construction intensity and cost associated with traditional cast-in-place structures used in existing excavated tunnels for transportation infrastructure, this utility model provides a city gate-type tunnel lining structure.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] This utility model proposes a tunnel lining structure of the city gate type, including two symmetrically trimmed bottom corner areas of the surrounding rock layer at the bottom of the tunnel, a first lining layer is provided on the top of the two bottom corner areas that are attached to the tunnel wall; and a second lining layer is provided between the two bottom corner areas.

[0007] Anchors are provided on the bottom corner area of ​​the surrounding rock, the second lining layer and the first lining layer, and the anchors are fixed in the surrounding rock layer of the tunnel.

[0008] Preferably, the anchor includes a first anchor rod, a second anchor rod, and a third anchor rod. One end of each of the first, second, and third anchor rods is installed in the surrounding rock layer of the tunnel. The other end of the first anchor rod is connected to the first lining layer, the other end of the second anchor rod is connected to the bottom corner area of ​​the surrounding rock, and the other end of the third anchor rod is connected to the second lining layer.

[0009] Preferably, a first anchor bar is provided in the bottom corner area of ​​the surrounding rock and on the first lining layer, and the first anchor bar is installed in the surrounding rock layer of the tunnel.

[0010] Preferably, the angle between the first anchor bar and the anchor is in the range of 12° to 18°.

[0011] Preferably, multiple reinforcing ribs are provided between the bottom corner area of ​​the surrounding rock and the first lining layer along the height direction of the tunnel, and between the bottom corner area of ​​the surrounding rock and the second lining layer along the width direction of the tunnel, with the multiple reinforcing ribs arranged at equal intervals.

[0012] Preferably, the diameter of the reinforcing rib is in the range of 25mm to 32mm.

[0013] Preferably, second anchor bars are respectively provided on both sides of the anchor on the second lining layer, and the second anchor bars are fixed in the surrounding rock layer of the tunnel.

[0014] Preferably, the angle between the second anchor member and the upper surface of the second lining layer is 45°~60°.

[0015] Preferably, the first lining layer is arch-shaped.

[0016] Preferably, the thickness of the first lining layer is in the range of 30cm to 50cm.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] This utility model proposes a tunnel lining structure in the form of a city gate. This lining structure modifies the excavated tunnel, creating two bottom corner zones on either side of the tunnel bottom. This reduces construction work, effectively disperses pressure on the tunnel bottom, enhances the bottom bearing capacity, and reduces the risk of tunnel bottom deformation and damage due to changes in geological conditions or long-term loads. The first lining layer is tightly bonded to the top of the bottom corner zones, further reinforcing the tunnel wall and improving overall impermeability and durability. The second lining layer is positioned between the two bottom corner zones, forming a smooth passageway within the tunnel. This lining structure reduces construction work, provides a pre-defined support method for the connection between the surrounding rock and the lining, and fully utilizes the bearing capacity of the relatively intact bedrock at the invert arch location. This avoids the waste of extensive excavation and the construction of a separate reinforced concrete invert arch, significantly reducing the amount of secondary excavation work and saving on the amount of concrete for secondary lining, thus lowering construction costs.

[0019] Furthermore, this lining structure, through two L-shaped bottom corner areas of the surrounding rock layer that are symmetrically modified at the bottom of the tunnel surrounding rock layer, the first lining layer, the second lining layer, and structural components such as anchors, anchor bars, and reinforcing bars, can effectively bear the pressure load applied by the surrounding rock layer and ensure the safety and stability of the tunnel structure. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of a city gate-type tunnel lining structure proposed in this utility model;

[0021] Figure 2 for Figure 1 Cross-sectional view at point aa;

[0022] Figure 3 for Figure 2 Cross-sectional view at point bb;

[0023] In the attached diagram: 1. Anchor; 2. First anchor bar; 3. Second anchor bar; 4. Bottom corner area of ​​surrounding rock; 5. First lining layer; 6. Reinforcing bar; 7. Second lining layer. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0025] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0030] This utility model provides a tunnel lining structure for a city gate-type tunnel. This lining structure is based on a tunnel excavated using a full-face hard rock tunnel boring machine, with a small-scale secondary excavation and a pre-reserved support method for the connection between the surrounding rock and the lining. This significantly reduces the amount of secondary excavation work and saves on the amount of concrete used for the secondary lining, thus lowering construction costs. The specific structure is as follows: Figures 1-3 As shown, this lining structure includes two L-shaped bottom corner zones 4 symmetrically trimmed at the bottom of the tunnel's surrounding rock layer. The two L-shaped bottom corner zones 4 are symmetrically arranged. A first lining layer 5 is provided on the top of the two bottom corner zones 4, adhering to the tunnel wall. The radius of the outer wall of the first lining layer 5 is determined by the radius R1 of the full-section hard rock tunnel boring machine. The first lining layer 5 adopts an arch-shaped structure, with a thickness ranging from 30cm to 100cm, preferably 60cm. The two bottom corner zones 4... A second lining layer 7 is provided between the two rock-bottom corner areas 4 and the outer end face of the second lining layer 7. The two rock-bottom corner areas 4 and the second lining layer 7 form a flat road surface. Anchors 1 are provided on the rock-bottom corner area 4, the second lining layer 7 and the first lining layer 5. The anchors 1 are fixed in the surrounding rock layer of the tunnel. The anchors 1 increase the stability of the tunnel after the second excavation of the rock-bottom corner area 4, the second lining layer 7 and the first lining layer 5, and increase the strength of this lining structure.

[0031] like Figure 1 As shown, the anchor 1 includes multiple first anchor rods, multiple second anchor rods, and multiple third anchor rods. One end of each of the multiple first anchor rods, multiple second anchor rods, and multiple third anchor rods is installed in the surrounding rock layer of the tunnel. The other end of each of the multiple first anchor rods is connected to the first lining layer 5, the other end of each of the multiple second anchor rods is connected to the bottom corner area 4 of the surrounding rock, and the other end of each of the multiple third anchor rods is connected to the second lining layer 7. The diameter of each of the first, second, and third anchor rods is 25mm. The lengths of the first anchor rods are 32mm, preferably 28mm. The spacing between the first anchor rods at one end of the first lining layer 5 is 2m. The spacing between the second anchor rods at one end of the surrounding rock bottom corner area 4 is 2m. The spacing between the third anchor rods at one end of the second lining layer 7 is 2m. The lengths of the first, second, and third anchor rods range from 3m to 6m. In this embodiment, three third anchor rods are provided at a certain cross section (obtained by cutting along the tunnel width direction) on the second lining layer 7. The three third anchor rods are vertically installed on the second lining layer 7. Nine first anchor rods are provided at the same cross section on the first lining layer 5 and the second lining layer 7. The nine first anchor rods are equally spaced around the second lining layer 7. Two second anchor rods are provided at the same cross section on each surrounding rock bottom corner area 4 and the second lining layer 7.

[0032] like Figure 1 As shown, first anchor bars 2 are provided on both the bottom corner area 4 of the surrounding rock and the first lining layer 5. The first anchor bars 2 are installed in the surrounding rock layer of the tunnel. The angle between the first anchor bars 2 and the anchor 1 is 12°~18°. The first anchor bars 2 on the bottom corner area 4 of the surrounding rock are located near the connection between the first anchor bar 2 and the first lining layer 5. One end of the first anchor bars 2 on the bottom corner area 4 coincides with one end of a second anchor rod installed on it. The first anchor bars 2 on the first lining layer 5 are located near its bottom end, and one end of the first anchor bars 2 coincides with the connection point of the first anchor rod installed at that position. The angle between the two is preferably 15°. The first anchor bars 2 further increase the stability of the lining structure, improve the mechanical properties of the soil and rock, and enhance the shear strength of the lining structure. In this embodiment, the diameter of the first anchor bars 2 is 28mm and the length is 3-5 meters.

[0033] like Figure 2 and Figure 3As shown, multiple reinforcing ribs 6 are respectively arranged along the width direction of the tunnel between the bottom corner area 4 of the surrounding rock and the first lining layer 5, and along the height direction of the tunnel between the bottom corner area 4 of the surrounding rock and the second lining layer 7. The multiple reinforcing ribs 6 are arranged at equal intervals. In this embodiment, the multiple reinforcing ribs 6 between the bottom corner area 4 of the surrounding rock and the first lining layer 5 are arranged in three rows at equal intervals along the width direction of the tunnel, and the multiple reinforcing ribs 6 between the bottom corner area 4 of the surrounding rock and the second lining layer 7 are also arranged in three rows at equal intervals along the height direction of the tunnel. The distance between the center points of two reinforcing ribs 6 located at the same cross section in two adjacent rows is 15cm~20cm, preferably 18cm. The diameter of the reinforcing rib 6 ranges from 25mm to 32mm, preferably 28mm. The length of the reinforcing rib 6 is 35 times its diameter. The reinforcing rib 6 increases the stability of the connection between the bottom corner area 4 of the surrounding rock and the first lining layer 5, and the bottom corner area 4 of the surrounding rock and the second lining layer 7, thereby making the bottom corner area 4 of the surrounding rock, the first lining layer 5 and the second lining layer 7 form a whole. At the same time, it improves the overall stiffness and load-bearing capacity of the lining structure.

[0034] Second anchor bars 3 are respectively provided on both sides of the anchor 1 on the second lining layer 7. The second anchor bars 3 are fixed in the surrounding rock layer of the tunnel. The angle between the second anchor bars 3 and the upper surface of the second lining layer 7 is 45°~60°. In this embodiment, the second anchor bars 3 include multiple second anchor bars. One end of the multiple second anchor bars is connected to the second lining layer 7, and the other end of the multiple second anchor bars is connected to the surrounding rock layer of the tunnel around the second lining layer 7. The multiple second anchor bars located at one end of the second lining layer 7 are arranged at a spacing of 2m along the length of the tunnel. Among the multiple second anchor bars arranged at equal intervals, if the angle between the axis of one second anchor bar and the upper surface of the second lining layer 7 is 60°, then the angle between the two adjacent second anchor bars and the upper surface of the second lining layer 7 is 45°. In this embodiment, the diameter of the second anchor bar 3 is 28mm and the length is 3~5m. The second anchor bars 3 can improve the anchoring effect between the second lining layer 7 and the surrounding rock layer.

[0035] Both the first lining layer 5 and the second lining layer 7 are made of cast concrete to ensure sufficient strength and durability of the structure. This lining structure, through structural components such as anchors, reinforcing bars, and ribs, can effectively bear the pressure loads applied by the surrounding rock strata, ensuring the safety and stability of the tunnel structure.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications made to the technical solutions based on the technical concept proposed by this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. A tunnel lining structure in the form of a city gate, characterized in that, The tunnel includes two symmetrically trimmed bottom corner areas (4) of the surrounding rock layer, with a first lining layer (5) provided on the top of the two bottom corner areas (4) and attached to the tunnel wall; and a second lining layer (7) provided between the two bottom corner areas (4). Anchors (1) are provided on the bottom corner area (4) of the surrounding rock, the second lining layer (7) and the first lining layer (5), and the anchors (1) are fixed in the surrounding rock layer of the tunnel.

2. The tunnel lining structure of the city gate type according to claim 1, characterized in that, The anchor (1) includes a first anchor rod, a second anchor rod and a third anchor rod. One end of the first anchor rod, the second anchor rod and the third anchor rod are all installed in the surrounding rock layer of the tunnel. The other end of the first anchor rod is connected to the first lining layer (5). The other end of the second anchor rod is connected to the bottom corner area (4) of the surrounding rock. The other end of the third anchor rod is connected to the second lining layer (7).

3. The tunnel lining structure of the city gate type according to claim 1, characterized in that, The bottom corner area (4) of the surrounding rock and the first lining layer (5) are provided with a first anchor bar (2), which is installed in the surrounding rock layer of the tunnel.

4. The tunnel lining structure of the city gate type according to claim 3, characterized in that, The angle between the first anchor bar (2) and the anchor (1) is 12°~18°.

5. The tunnel lining structure of the city gate type according to claim 1, characterized in that, Multiple reinforcing ribs (6) are provided between the bottom corner area (4) of the surrounding rock and the first lining layer (5) along the height direction of the tunnel, and between the bottom corner area (4) of the surrounding rock and the second lining layer (7) along the width direction of the tunnel. The multiple reinforcing ribs (6) are arranged at equal intervals.

6. The tunnel lining structure of the city gate type according to claim 5, characterized in that, The direct range of the reinforcing rib (6) is 25mm to 32mm.

7. The tunnel lining structure of the city gate type according to claim 1, characterized in that, On the second lining layer (7), second anchor bars (3) are respectively provided on both sides of the anchor (1), and the second anchor bars (3) are fixed in the surrounding rock layer of the tunnel.

8. The tunnel lining structure of the city gate type according to claim 7, characterized in that, The horizontal angle between the second anchor bar (3) and the upper surface of the second lining layer (7) is 45°~60°.

9. The tunnel lining structure of the city gate type according to claim 1, characterized in that, The first lining layer (5) is arch-shaped.

10. A tunnel lining structure of the city gate type according to claim 9, characterized in that, The thickness of the first lining layer (5) ranges from 30cm to 100cm.

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