Underground cavern supporting structure and underground cavern
By setting up auxiliary tunnels on the outside of the main cavern pressure arch and using through anchor cables for reinforcement, the problem of deep surrounding rock reinforcement in underground caverns was solved, achieving uniform distribution of reinforcement force field and long-term stability improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NORTHWEST ENGINEERING CORPORATION LIMITED
- Filing Date
- 2025-05-22
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies are unable to effectively reinforce the deep, weak surrounding rock within the pressure arch of underground caverns, resulting in insufficient long-term stability of the underground caverns.
Multiple auxiliary tunnels are set outside the pressure arch crown of the main cavern. The auxiliary tunnels are connected to the main cavern by through-cable anchors to form deep anchoring bases for the through-cable anchors. Auxiliary tunnels are set at intervals along the circumference of the pressure arch crown to reinforce the rock mass within the pressure arch area.
It effectively reinforces the weak surrounding rock deep inside the pressure arch, ensuring the long-term stable operation of the underground cavern and making the reinforcement force field evenly distributed, thus improving the long-term stability of the underground cavern.
Smart Images
Figure CN224120262U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of underground cavern technology, and more specifically, to an underground cavern support structure and an underground cavern. Background Technology
[0002] In the construction of infrastructure such as traffic tunnels, water conservancy and hydropower water diversion systems, and energy storage facilities, it is usually necessary to manually excavate large underground caverns. The design and construction of underground caverns must comprehensively address complex geological conditions, hydrological environment, and long-term operational stability requirements.
[0003] Currently, underground cavern construction typically employs support theories such as the New Austrian Tunneling Method (NATM) or the Norwegian Method, using initial shotcrete and anchor support combined with secondary lining to form a composite load-bearing system. However, based on Protodyakonov's pressure arch theory, after excavation, the rock mass above the pressure arch remains undisturbed, while the rock mass below it will loosen and eventually collapse. These traditional support methods cannot effectively reinforce the weak surrounding rock deep within the pressure arch, making it difficult to meet the long-term stability requirements of underground caverns. Utility Model Content
[0004] The problem solved by this invention is how to deeply reinforce the surrounding rock of underground caverns.
[0005] To solve the above problems, this utility model provides an underground cavern support structure and an underground cavern.
[0006] On the one hand, this utility model provides an underground cavern support structure, including multiple auxiliary caverns arranged parallel to the main cavern. The auxiliary caverns are located outside the arch of the pressure arch of the main cavern, and the auxiliary caverns are spaced apart circumferentially along the arch of the pressure arch. Multiple through anchor cables are provided between each auxiliary cavern and the main cavern to reinforce the rock mass within the range of the pressure arch.
[0007] Optionally, the cross-section of the pressure arch is arched at the top and inverted trapezoidal at the bottom.
[0008] Optionally, there are five auxiliary holes in total, namely, a first auxiliary hole, a second auxiliary hole, a third auxiliary hole, a fourth auxiliary hole, and a fifth auxiliary hole;
[0009] The first auxiliary hole is located above the center of the main chamber; the second and third auxiliary holes are located on both sides of the top of the side wall of the main chamber; the fourth and fifth auxiliary holes are located diagonally above the arch of the main chamber.
[0010] Optionally, a vertically arranged through-cable cable is provided between the first auxiliary tunnel and the vault of the main tunnel;
[0011] The second auxiliary tunnel and the third auxiliary tunnel are respectively provided with horizontally arranged through-cable cables between the corresponding side walls of the main tunnel and the side walls of the main tunnel. The second auxiliary tunnel and the third auxiliary tunnel are also respectively provided with inclined through-cable cables between the corresponding side walls of the main tunnel and the side walls of the main tunnel.
[0012] Inclined through-cable cables are respectively installed between the fourth auxiliary tunnel and the fifth auxiliary tunnel and the arch on the corresponding side of the main tunnel.
[0013] Optionally, the main cavern's arch is a three-centered circular arch, and the extension lines of the through-cables between the fourth auxiliary cavern and the fifth auxiliary cavern and the main cavern all pass through the center of the middle circle of the three-centered circular arch; the through-cables between the fourth auxiliary cavern and the fifth auxiliary cavern and the main cavern are arranged at an angle of 25°-35° to the vertical direction.
[0014] Optionally, a first drainage corridor is provided below the second auxiliary tunnel, and a second drainage corridor is provided at the bottom of the third auxiliary tunnel; the auxiliary tunnel, the first drainage corridor, and the second drainage corridor are connected through drainage holes to form the drainage system of the main tunnel.
[0015] Optionally, the drainage hole includes a first drainage hole, a second drainage hole, and a third drainage hole. The first drainage hole connects the second auxiliary hole and the first drainage corridor. The second drainage hole connects the second auxiliary hole and the fourth auxiliary hole. One end of the third drainage hole connects to the fourth auxiliary hole, and the other end extends to the top of the first auxiliary hole. The second auxiliary hole and the fourth auxiliary hole are located on the same side of the main chamber.
[0016] And / or, the drainage hole further includes a fourth drainage hole, a fifth drainage hole, and a sixth drainage hole, wherein the fourth drainage hole connects the third auxiliary hole and the second drainage corridor; the fifth drainage hole connects the third auxiliary hole and the fifth auxiliary hole; one end of the sixth drainage hole connects to the fifth auxiliary hole, and the other end extends to the top of the first auxiliary hole; the third auxiliary hole and the fifth auxiliary hole are located on the same side of the main chamber.
[0017] Optionally, the underground cavern support structure is symmetrical about the longitudinal center plane of the main cavern.
[0018] Optionally, the initial support structure of the inner wall of the main cavern includes a steel mesh, a shotcrete layer, and an anchor system, with the anchors of the through-cables being installed in the shotcrete layer.
[0019] On the other hand, this utility model provides an underground cavern with the above-mentioned underground cavern support structure.
[0020] The beneficial effects of this utility model's underground cavern support structure and underground cavern are as follows: By setting multiple auxiliary holes on the outer side of the pressure arch of the main cavern as deep anchoring bases for the through-cable cables, and by installing multiple through-cable cables between each auxiliary hole and the main cavern, the through-cable cables extend from the stable rock mass outside the pressure arch through the weak rock mass inside to the main cavern, forming a compaction and reinforcement system for all weak surrounding rock within the coverage area of the pressure arch. This effectively reinforces the deep weak surrounding rock inside the pressure arch, ensuring the long-term stable operation of the underground cavern. Furthermore, the multiple auxiliary holes are spaced apart circumferentially along the arch of the pressure arch, making the reinforcement force field applied to the through-cable cables more uniform, resulting in a better reinforcement effect on the weak surrounding rock mass within the pressure arch. Attached Figure Description
[0021] Figure 1 This is a cross-sectional structural diagram of the underground cavern support structure according to an embodiment of the present utility model.
[0022] Figure 2 for Figure 1 BB cross-section diagram.
[0023] Figure 3 This is an enlarged view of part A of the underground cavern support structure according to an embodiment of the present invention.
[0024] Explanation of reference numerals in the attached figures:
[0025] 1. Main chamber; 21. First auxiliary tunnel; 22. Second auxiliary tunnel; 23. Third auxiliary tunnel; 24. Fourth auxiliary tunnel; 25. Fifth auxiliary tunnel; 3. Pressure arch; 4. Through-cable anchor; 40. Anchorage; 51. First drainage gallery; 52. Second drainage gallery; 61. First drainage hole; 62. Second drainage hole; 63. Third drainage hole; 64. Fourth drainage hole; 65. Fifth drainage hole; 66. Sixth drainage hole; 71. Reinforcing mesh; 72. Shotcrete layer; 73. Anchor system. Detailed Implementation
[0026] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.
[0027] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optionally an embodiment". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.
[0028] It should be noted that the terms "one" and "multiple" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be interpreted as "one or more". In this utility model, "outer" refers to the side furthest from the center of the main chamber 1, and "inner" refers to the side closest to the center of the main chamber 1; "left" refers to... Figure 1 In the X direction, "right" refers to Figure 1 The opposite direction of the X direction, "up" refers to Figure 1 In the Y direction, "down" refers to Figure 1 The opposite direction of the Y-axis.
[0029] like Figure 1 As shown in the figure, the underground cavern support structure provided by this utility model includes multiple auxiliary caverns arranged parallel to the main cavern 1. The auxiliary caverns are located outside the arch top of the pressure arch 3 of the main cavern 1, and the auxiliary caverns are spaced apart along the circumferential direction of the arch top of the pressure arch 3. Multiple through anchor cables 4 are provided between each auxiliary cavern and the main cavern 1 to reinforce the rock mass within the range of the pressure arch 3.
[0030] In this embodiment, multiple auxiliary holes are set on the outer side of the arch of the pressure arch 3 in the main cavern 1 as deep anchoring bases for the through-cable cables 4. Multiple through-cable cables 4 are installed between each auxiliary hole and the main cavern 1, allowing the through-cable cables 4 to penetrate from the stable rock mass outside the pressure arch 3 through the weak rock mass inside and extend to the main cavern 1. This forms a compaction and reinforcement system for all weak surrounding rock within the coverage area of the pressure arch 3, effectively reinforcing the deep weak surrounding rock inside the pressure arch 3 and ensuring the long-term stable operation of the underground cavern. Furthermore, the multiple auxiliary holes are spaced apart circumferentially along the arch of the pressure arch 3, making the reinforcement force field applied to the through-cable cables 4 more uniform and resulting in a better reinforcement effect on the weak surrounding rock mass within the pressure arch 3.
[0031] Optionally, the cross-section of the pressure arch 3 has an arched top and an inverted trapezoidal bottom.
[0032] In this optional embodiment, the cross-section of the pressure arch 3 is a composite shape of an upper arch and a lower trapezoid. Its top is a pressure-optimized arch structure, such as a parabolic arch, and its bottom is an inverted trapezoid shape. This pressure arch 3 is calculated based on Protodyakonov's pressure arch theory. The main chamber 1 with this pressure arch 3 shape generally has a straight-wall arch cross-section, and the slope of the top arch is relatively gentle.
[0033] Optionally, there are five auxiliary tunnels, namely the first auxiliary tunnel 21, the second auxiliary tunnel 22, the third auxiliary tunnel 23, the fourth auxiliary tunnel 24, and the fifth auxiliary tunnel 25; the first auxiliary tunnel 21 is located above the center of the main tunnel 1; the second auxiliary tunnel 22 and the third auxiliary tunnel 23 are located on both sides of the top of the side wall of the main tunnel 1, and the fourth auxiliary tunnel 24 and the fifth auxiliary tunnel 25 are located diagonally above the arch of the main tunnel 1.
[0034] In this optional embodiment, there are five auxiliary holes, spaced apart circumferentially along the crown of the pressure arch 3. Specifically, as shown... Figure 1 As shown, the first auxiliary hole 21 is located above the main chamber 1; the second auxiliary hole 22 and the third auxiliary hole 23 are located on both sides of the top of the side wall of the main chamber 1; and the fourth auxiliary hole 24 and the fifth auxiliary hole 25 are located on both sides of the arch of the main chamber 1 at an angle above, so that the auxiliary holes are arranged in a spatial five-point layout along the circumference of the arch of the pressure arch 3. This layout constitutes a spatial support skeleton for a three-dimensional reinforcement force field.
[0035] Optionally, vertically arranged through-cable cables 4 are installed between the first auxiliary tunnel 21 and the arch of the main chamber 1; horizontally arranged through-cable cables 4 are installed between the second auxiliary tunnel 22 and the corresponding sidewall of the main chamber 1, and inclined through-cable cables 4 are also installed between the second auxiliary tunnel 22 and the corresponding sidewall of the main chamber 1; inclined through-cable cables 4 are installed between the fourth auxiliary tunnel 24 and the corresponding arch of the main chamber 1. It should be noted that the second auxiliary tunnel 22 and the fourth auxiliary tunnel 24 are located on the same side of the main chamber 1, such as... Figure 1 All shown are located on the left side; the through anchor 4 installed on the fourth auxiliary tunnel 24 is located between the through anchor 4 installed on the first auxiliary tunnel 21 and the through anchor 4 installed on the second auxiliary tunnel 22.
[0036] In this optional embodiment, the vertical through-cable 4 between the first auxiliary tunnel 21 and the arch of the main chamber 1 forms a vertical load-bearing structure; the horizontal through-cable 4 between the second auxiliary tunnel 22 and the sidewall of the main chamber 1 forms a horizontal load-bearing structure on one side; the inclined through-cable 4 between the second auxiliary tunnel 22 and the sidewall of the main chamber 1 forms an inclined load-bearing structure at the sidewall; and the inclined through-cable 4 between the fourth auxiliary tunnel 24 and the main chamber 1 forms an inclined load-bearing structure at the arch. The synergistic effect of the pressure prestressing of the four through-cable 4 in these directions effectively reinforces the surrounding rock on the left side inside the pressure arch 3.
[0037] In addition, on the right side of the main cavern 1, horizontally arranged through-cable cables 4 are installed between the third auxiliary tunnel 23 and the corresponding side wall of the main cavern 1, and inclined through-cable cables 4 are also installed between the third auxiliary tunnel 23 and the corresponding side wall of the main cavern 1; inclined through-cable cables 4 are installed between the fifth auxiliary tunnel 25 and the arch on the corresponding side of the main cavern 1, so that the surrounding rock on the right side inside the pressure arch 3 is effectively reinforced.
[0038] Optionally, the through anchor cables 4, arranged at an angle of 25°-35° to the horizontal direction, are positioned between the sidewalls of the second auxiliary tunnel 22 and the main tunnel 1. Figure 1 In this case, the angle n takes values between 25° and 35°.
[0039] In this optional embodiment, such as Figure 1 As shown, inclined through-cables 4 are also installed between the second auxiliary tunnel 22 and the sidewall of the main tunnel 1, extending obliquely downward from the second auxiliary tunnel 22 to the middle of the sidewall of the main tunnel 1 to reinforce the surrounding rock on the left side of the sidewall of the main tunnel 1.
[0040] In addition, the through anchor cables 4, which are inclined between the sidewalls of the third auxiliary tunnel 23 and the main tunnel 1, are at an angle of 25°-35° to the horizontal direction.
[0041] Optionally, the arch of the main chamber 1 is a three-centered circular arch, and the extension line of the through anchor cable 4 between the fourth auxiliary tunnel 24 and the main chamber 1 passes through the center of the middle circle of the three-centered circular arch; the through anchor cable 4 between the fourth auxiliary tunnel 24 and the main chamber 1 is arranged at an angle of 25°-35° to the vertical direction.
[0042] In this embodiment, the main chamber 1's arch adopts a three-centered circular arch structure. The through-cable 4 between the fourth auxiliary tunnel 24 and the main chamber 1 is precisely aligned with the geometric center of the central circle of the three-centered circular arch and arranged at an optimal inclination angle of 25°-35°. Figure 1 The midpoint m is set between 25° and 35°. In addition, the extension line of the through anchor cable 4 between the fifth auxiliary tunnel 25 and the main tunnel 1 passes through the center of the middle circle of the three-centered arch; the through anchor cable 4 between the fifth auxiliary tunnel 25 and the main tunnel 1 is arranged at an angle of 25° to 35° with respect to the vertical direction.
[0043] Optionally, the through anchor cables 4 are arranged at intervals along the axial direction of the main chamber 1; the auxiliary tunnel is set at a position 3-4.5m outside the pressure arch 3.
[0044] In this optional embodiment, the through-anchor cables 4 are arranged at intervals along the axial direction of the main cavern 1, with a spacing of generally 1-1.5m; that is, each auxiliary cavern is provided with multiple through-anchor cables 4 at intervals along its axial direction, with one end of the through-anchor cable 4 located inside the auxiliary cavern and the other end located inside the main cavern 1. The auxiliary cavern is located 3-4.5m outside the pressure arch 3 to ensure that the auxiliary cavern is located in stable rock mass outside the pressure arch 3.
[0045] Optionally, a first drainage corridor 51 is provided below the second auxiliary tunnel 22, and a second drainage corridor 52 is provided at the bottom of the third auxiliary tunnel 23; the auxiliary tunnels, the first drainage corridor 51 and the second drainage corridor 52 are connected through drainage holes to form the drainage system of the main tunnel 1.
[0046] In this optional embodiment, the auxiliary tunnel has a drainage function, serving both as a deep anchoring point for the through anchor cable 4 and as a drainage gallery. The auxiliary tunnel, the first drainage gallery 51, the second drainage gallery 52, and the drainage holes constitute the drainage system of the main chamber 1, preventing groundwater from entering the area within the pressure arch 3 and softening the rock mass therein, thereby further improving the stability of the main chamber 1.
[0047] Optionally, the drainage holes include a first drainage hole 61, a second drainage hole 62, and a third drainage hole 63. The first drainage hole 61 connects the second auxiliary hole 22 and the first drainage corridor 51; the second drainage hole 62 connects the second auxiliary hole 22 and the fourth auxiliary hole 24; one end of the third drainage hole 63 connects to the fourth auxiliary hole 24, and the other end extends to the top of the first auxiliary hole 21. It should be noted that the second auxiliary hole 22 and the fourth auxiliary hole 24 are located on the same side of the main chamber 1, that is, both are located on the left side.
[0048] In this optional embodiment, the first drainage hole 61 is arranged vertically, with one end connected to the second auxiliary hole 22 and the other end connected to the first drainage corridor 51; the second drainage hole 62 is connected to the second auxiliary hole 22 at one end and to the fourth auxiliary hole 24 at the other end; the third drainage hole 63 is connected to the fourth auxiliary hole 24 at one end and extends to the top of the first auxiliary hole 21 at the other end, forming an orderly drainage system.
[0049] In addition, multiple drainage holes 61, 62, and 63 are provided along the axial direction of the main chamber 1, with a spacing of approximately 2-3 meters. The drainage system also includes a fourth drainage hole 64, a fifth drainage hole 65, and a sixth drainage hole 66. The fourth drainage hole 64 connects the third auxiliary tunnel 23 to the second drainage corridor 52; the fifth drainage hole 65 connects the third auxiliary tunnel 23 to the fifth auxiliary tunnel 25; and the sixth drainage hole 66 connects to the fifth auxiliary tunnel 25 at one end and extends to the top of the first auxiliary tunnel 21 at the other end. The third auxiliary tunnel 23 and the fifth auxiliary tunnel 25 are located on the same side of the main chamber 1, i.e., both are on the right side.
[0050] like Figure 1 As shown, the other ends of the third drainage hole 63 and the sixth drainage hole 66 both extend to the top of the first auxiliary hole 21 and intersect each other to increase the overall drainage effect.
[0051] Optionally, the underground cavern support structure is symmetrical about the longitudinal center plane of the main cavern 1. Specifically, the aforementioned auxiliary caverns, pressure arches 3, through anchor cables 4, drainage holes, and other structures are all bilaterally symmetrical.
[0052] Optionally, such as Figure 2 and Figure 3 As shown, the inner wall of the main chamber 1 is provided with a concrete spray layer 72, and the anchor 40 of the through anchor cable 4 is set in the concrete spray layer 72 to ensure reliable anchoring.
[0053] In addition, the initial support structure of the inner wall of the main tunnel 1 typically includes a steel mesh 71, a shotcrete layer 72, and an anchor system 73. The thickness of the shotcrete layer 72 is generally 15cm-20cm, and it needs to be thickened when anchors 40 are installed. The anchors of the anchor system 73 are spaced 1m-1.5m apart along the axial direction of the main tunnel 1. The anchor system 73 includes ordinary anchors and prestressed anchors installed at the arch foot of the main tunnel 1 to prevent failure due to stress concentration. The length of the prestressed anchors is 9-12m.
[0054] During the actual construction, firstly, the location and size of the main tunnel 1 are determined, and based on the internal friction angle, cohesion and uniaxial compressive strength of the surrounding rock mass of the main tunnel 1, the size and range of the pressure arch 3 are determined according to Protodyakonov's pressure arch theory.
[0055] Next, auxiliary tunnels were excavated above the center of the main tunnel 1 arch, on both sides diagonally above, and on the outer side of the top of the sidewalls. Simultaneously, the first drainage corridor 51 and the second drainage corridor 52 were excavated, and drainage holes were constructed to form an orderly drainage system.
[0056] Then, based on the relative positions of the auxiliary tunnel and the main tunnel 1, drilling is carried out from the auxiliary tunnel to the main tunnel 1 to facilitate the timely installation of through anchor cables 4 after the main tunnel 1 is excavated.
[0057] Finally, the main tunnel 1 is excavated in layers from top to bottom, prioritizing the location for the installation of the through anchor cables 4. After excavating enough construction space, the open face of the main tunnel 1 is initially supported, including hanging steel mesh 71, spraying concrete 72, installing the anchor system 73, and promptly installing the through anchor cables 4 to achieve compaction and reinforcement of the surrounding rock inside the pressure arch 3.
[0058] This utility model embodiment also provides an underground cavern with the aforementioned underground cavern support structure. Multiple auxiliary holes are set on the outer side of the arch crown of the pressure arch 3 of the main cavern 1, serving as deep anchoring bases for the through-cable cables 4. Multiple through-cable cables 4 are installed between each auxiliary hole and the main cavern 1, allowing the through-cable cables 4 to extend from the stable rock mass outside the pressure arch 3 through the weak rock mass inside to the main cavern 1, forming a compaction and reinforcement system for all weak surrounding rock within the coverage area of the pressure arch 3. This effectively reinforces the deep weak surrounding rock within the pressure arch 3, ensuring the long-term stable operation of the underground cavern. Furthermore, the multiple auxiliary holes are spaced apart circumferentially along the arch crown of the pressure arch 3, resulting in a more uniform reinforcement force field applied to the through-cable cables 4, leading to a better reinforcement effect on the weak surrounding rock mass within the pressure arch 3.
[0059] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.
Claims
1. A support structure for an underground cavern, characterized in that, It includes multiple auxiliary tunnels arranged parallel to the main tunnel (1). The auxiliary tunnels are located outside the arch top of the pressure arch (3) of the main tunnel (1), and the auxiliary tunnels are spaced apart around the arch top of the pressure arch (3). Each auxiliary tunnel is provided with multiple through anchors (4) between it and the main tunnel (1) to reinforce the rock mass within the range of the pressure arch (3).
2. The underground cavern support structure according to claim 1, characterized in that, The pressure arch (3) has an arched top and an inverted trapezoidal bottom.
3. The underground cavern support structure according to claim 1, characterized in that, There are five auxiliary holes, namely the first auxiliary hole (21), the second auxiliary hole (22), the third auxiliary hole (23), the fourth auxiliary hole (24) and the fifth auxiliary hole (25). The first auxiliary hole (21) is located above the center of the main cavern (1); the second auxiliary hole (22) and the third auxiliary hole (23) are located on both sides of the top of the side wall of the main cavern (1); the fourth auxiliary hole (24) and the fifth auxiliary hole (25) are located on both sides of the arch of the main cavern (1) at an angle above.
4. The underground cavern support structure according to claim 3, characterized in that, The first auxiliary tunnel (21) and the arch of the main tunnel (1) are provided with vertically arranged through anchor cables (4). The second auxiliary hole (22) and the third auxiliary hole (23) are respectively provided with horizontally arranged through-cables (4) between the side walls of the corresponding side of the main cave (1), and the second auxiliary hole (22) and the third auxiliary hole (23) are respectively provided with inclined through-cables (4) between the side walls of the corresponding side of the main cave (1). Inclined through-cables (4) are respectively installed between the fourth auxiliary tunnel (24) and the fifth auxiliary tunnel (25) and the arch on the corresponding side of the main tunnel (1).
5. The underground cavern support structure according to claim 4, characterized in that, The main cavern (1) has a three-centered circular arch. The extension lines of the through anchor cables (4) between the fourth auxiliary cavern (24) and the fifth auxiliary cavern (25) and the main cavern (1) all pass through the center of the middle circle of the three-centered circular arch. The through anchor cables (4) between the fourth auxiliary cavern (24) and the fifth auxiliary cavern (25) and the main cavern (1) are arranged at an angle of 25°-35° to the vertical direction.
6. The underground cavern support structure according to claim 3, characterized in that, A first drainage corridor (51) is provided below the second auxiliary cave (22), and a second drainage corridor (52) is provided at the bottom of the third auxiliary cave (23); the auxiliary cave, the first drainage corridor (51) and the second drainage corridor (52) are connected by drainage holes to form the drainage system of the main cave (1).
7. The underground cavern support structure according to claim 6, characterized in that, The drainage holes include a first drainage hole (61), a second drainage hole (62), and a third drainage hole (63). The first drainage hole (61) connects the second auxiliary hole (22) with the first drainage corridor (51). The second drainage hole (62) connects the second auxiliary hole (22) with the fourth auxiliary hole (24). One end of the third drainage hole (63) connects to the fourth auxiliary hole (24), and the other end extends to the top of the first auxiliary hole (21). The second auxiliary hole (22) and the fourth auxiliary hole (24) are located on the same side of the main chamber (1). And / or, the drainage holes also include a fourth drainage hole (64), a fifth drainage hole (65) and a sixth drainage hole (66), the fourth drainage hole (64) connecting the third auxiliary hole (23) and the second drainage corridor (52); the fifth drainage hole (65) connecting the third auxiliary hole (23) and the fifth auxiliary hole (25); one end of the sixth drainage hole (66) connecting the fifth auxiliary hole (25) and the other end extending to the top of the first auxiliary hole (21); the third auxiliary hole (23) and the fifth auxiliary hole (25) are located on the same side of the main chamber (1).
8. The underground cavern support structure according to claim 1, characterized in that, The underground cavern support structure is symmetrical about the longitudinal center plane of the main cavern (1).
9. The underground cavern support structure according to claim 1, characterized in that, The initial support structure of the inner wall of the main cavern (1) includes a steel mesh (71), a shotcrete layer (72) and an anchor system (73), and the anchor (40) of the through anchor cable (4) is set in the shotcrete layer (72).
10. An underground cavern, characterized in that, Includes the underground cavern support structure as described in any one of claims 1-9.