Self-draining underground tunnel structure based on surrounding rock bearing capacity

Abstract

The application relates to a self-draining underground tunnel structure based on the bearing capacity of surrounding rock, which comprises a tunnel main body, a drainage part and a water guide part, the axial extension direction of the tunnel main body is arranged to be inclined along the inclination angle of the rock stratum trend, and the cross-sectional profile shape of the tunnel main body is horseshoe-shaped; the drainage part comprises a V-shaped water guide groove and multiple water collecting wells, the V-shaped water guide groove is arranged at the bottom of the tunnel main body, the length direction of the V-shaped water guide groove extends along the axial direction of the tunnel main body, the multiple water collecting wells are arranged at intervals along the axial direction of the tunnel main body at a preset interval, at least two submersible pumps are arranged in the water collecting well, and a drainage pipe is arranged in communication with the water outlet end of the submersible pump; the water guide part is arranged on the wall surface of the tunnel main body, the water guide part is in communication with the V-shaped water guide groove and can guide the water on the wall surface of the tunnel main body into the V-shaped water guide groove; the self-draining underground tunnel structure constructs a composite drainage system capable of high-efficiency drainage and emergency drainage, and is beneficial to realizing safe, stable and high-efficiency drainage of the tunnel main body.

Description

Technical Field

[0001] This application relates to the field of tunnel engineering technology, specifically to a self-draining underground tunnel structure based on the bearing capacity of the surrounding rock. Background Technology

[0002] In related technologies, traditional tunnels in water-rich strata generally adopt a drainage design concept of "primarily blocking, combined with drainage." The core of this approach is to lay a ring-shaped blind pipe (such as a spring-loaded permeable pipe or perforated PVC pipe) behind the initial support, and then wrap it with geotextile as a filter layer, ultimately diverting water into a side ditch for discharge. However, the effective operation of this drainage method relies on the natural accumulation of groundwater that can penetrate the geotextile and enter the pipe. In water-rich strata, the water is rich in fine-grained mud, sand, rock debris, and chemical deposits, making the geotextile filter layer extremely prone to clogging (i.e., the "siltation effect"). Once the filter layer fails, the blind pipe not only loses its drainage function but also becomes a water barrier against groundwater, causing continuous water pressure buildup behind the support structure. This results in the drainage system failing to provide reliable and stable drainage throughout the tunnel's entire lifespan, directly causing common operational problems such as lining leakage and ice damage, and posing a potential threat to the long-term safety of the lining structure due to the accumulation of water pressure behind it. Therefore, there is an urgent need for an active, controllable, and maintainable drainage technology to address these shortcomings. Summary of the Invention

[0003] This application provides a self-draining underground tunnel structure based on the bearing capacity of the surrounding rock. This self-draining underground tunnel structure based on the bearing capacity of the surrounding rock constructs a composite drainage system capable of efficient drainage and emergency drainage, which is conducive to achieving safe, stable and efficient drainage of the tunnel body.

[0004] The self-draining underground tunnel structure based on the bearing capacity of the surrounding rock provided in this application includes: a tunnel body, wherein the axial extension direction of the tunnel body is inclined along the rock stratum strike angle, and the cross-sectional outline of the tunnel body is horseshoe-shaped.

[0005] The drainage section includes a V-shaped water guide channel and multiple water collection wells. The V-shaped water guide channel is located at the bottom of the tunnel body and extends along the axial direction of the tunnel body. The multiple water collection wells are arranged at preset intervals along the axial direction of the tunnel body. At least two submersible pumps are installed in each water collection well, and the outlet end of each submersible pump is connected to a drainage pipe.

[0006] A water guiding section is disposed on the wall of the tunnel body. The water guiding section is connected to the V-shaped water guiding channel and can guide water from the wall of the tunnel body into the V-shaped water guiding channel.

[0007] In addition, the self-draining underground tunnel structure based on the bearing capacity of the surrounding rock provided in this application may also have the following additional technical features:

[0008] In one optional embodiment, the water guiding section includes a circumferential water collection channel and a longitudinal water guiding ditch. The circumferential water collection channel is arranged circumferentially along the inner wall of the tunnel body. There are multiple circumferential water collection channels, which are spaced apart along the axial direction of the tunnel body. The longitudinal water guiding ditch is arranged on both sides of the tunnel body axis, and the longitudinal water guiding ditch connects the circumferential water collection channel and the V-shaped water guiding channel.

[0009] In one alternative embodiment, the drainage section further includes a permeable grating disposed on one side of the top of the V-shaped water guide channel; the longitudinal water guide channel has a V-shaped cross-section and the wall of the longitudinal water guide channel is coated with an epoxy resin anti-seepage layer, the thickness of which is not less than 2 mm.

[0010] In one alternative embodiment, a stainless steel filter screen is detachably installed inside the circumferential water collection tank. The stainless steel filter screen has a pore size Φ of 2~3mm, an installation tilt angle γ of 55°~65°, and a maintenance slide rail is provided on one side of the bottom of the stainless steel filter screen.

[0011] In one alternative embodiment, the drainage pipe is laid overhead along the side wall of the tunnel body, and an electric butterfly valve is installed on the drainage pipe; the interval between the water collection wells is 500m, the interval between the circumferential water collection channels is 5~8m, the slope β of the bottom of the longitudinal water guide ditch is ≥2%, and the cross-sectional shape of the longitudinal water guide ditch is an inverted trapezoid.

[0012] In one alternative scheme, the slope angle α of the inclined arrangement of the tunnel body is 5°~8°, the angle θ between the axial direction of the tunnel body and the direction of the maximum principal stress of the surrounding rock is ≤30°, and the axial direction of the tunnel body forms an acute angle of 15°~25° with the orientation of the dominant joint surface.

[0013] In one alternative, the tunnel body is lined with steel fiber reinforced concrete, wherein the fiber content is 35~45kg / m³, the lining thickness T is 250~400mm, and T≥0.06D is satisfied.

[0014] In one optional scheme, the start and stop of the submersible pump is controlled by a PLC controller based on the set water level sensor signal; the at least two submersible pumps include at least one main pump and at least one standby pump. The main pump is started when the water level h ≥ 1.2m, the standby pump is started when the water level h ≥ 1.5m, and both the main pump and the standby pump are stopped when the water level h ≤ 0.5m.

[0015] The beneficial effects of this application are as follows:

[0016] The tunnel body in this application adopts a design that combines a horseshoe-shaped cross-section with a drainage section. A V-shaped water guide channel and a water collection well are set at the bottom of the tunnel body. The water collection well is set at the lowest point along the axis of the tunnel body and is arranged at intervals. A submersible pump is installed in the water collection well, so that active drainage can be carried out. In addition, the water guide section can guide water from the tunnel body wall into the V-shaped water guide channel to accelerate the drainage of water. The combination of various components constructs a composite drainage system that can carry out efficient drainage and emergency drainage, which is conducive to achieving safe, stable and efficient drainage of the tunnel body.

[0017] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0018] Figure 1 A schematic diagram of the cross-sectional structure of the self-draining underground tunnel structure provided in this application;

[0019] Figure 2 This is a schematic diagram of the longitudinal section of the self-draining underground tunnel structure provided in this application.

[0020] Attached reference numerals: 1. Tunnel body; 2. V-shaped water guide channel; 3. Water collection well; 4. Submersible pump; 5. Drainage pipe; 6. Circumferential water collection channel; 7. Longitudinal water guide ditch; 8. Permeable grid.

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0022] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0023] It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other technical solutions obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0026] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0027] like Figure 1-2 As shown in the figure, this application provides a self-draining underground tunnel structure based on the bearing capacity of the surrounding rock. This self-draining underground tunnel structure mainly includes a tunnel body 1, a drainage section, and a water guiding section. The tunnel body 1 is aligned with the orientation of the surrounding rock, and its axis extends at an angle diagonally along the strike of the rock strata. The cross-sectional outline of the tunnel body 1 is horseshoe-shaped. This design better adapts to the natural morphology of the underground rock strata, reduces tunnel deformation during construction, and improves overall structural stability. In addition, the drainage section includes a V-shaped water guide channel 2 and multiple water collection wells 3. The V-shaped water guide channel 2 is located at the bottom of the tunnel body 1, and the length direction of the V-shaped water guide channel 2 extends along the axial direction of the tunnel body 1. The V-shaped water guide channel 2 can effectively guide the water flow to the water collection wells 3. The multiple water collection wells 3 are arranged at preset intervals along the axial direction of the tunnel body 1. At least two submersible pumps 4 are installed in the water collection wells 3, and the outlet end of the submersible pumps 4 is connected to a drain pipe 5. The water guide section is located on the wall of the tunnel body 1. The water guide section is connected to the V-shaped water guide channel 2 and can guide the water on the wall of the tunnel body 1 into the V-shaped water guide channel 2.

[0028] In this embodiment of the self-draining underground tunnel structure, the tunnel body 1 adopts a design that combines a horseshoe-shaped cross section with a drainage section. A V-shaped water guide channel 2 and a water collection well 3 are provided at the bottom of the tunnel body 1. The water collection well 3 is located at the lowest point along the axis of the tunnel body 1 and is arranged at intervals. A submersible pump 4 is installed in the water collection well 3, so that active drainage can be carried out. In addition, the water guide section can guide water from the wall of the tunnel body 1 into the V-shaped water guide channel 2 to accelerate the drainage of water. The combination of various components constructs a composite drainage system that can carry out efficient drainage and emergency drainage, which is conducive to achieving safe, stable and efficient drainage of the tunnel body 1.

[0029] like Figure 1-2As shown, in one specific embodiment, the water guiding part includes a circumferential water collection channel 6 and a longitudinal water guiding ditch 7. The circumferential water collection channel 6 is arranged circumferentially along the inner wall of the tunnel body 1. There are multiple circumferential water collection channels 6, which are arranged at intervals along the axial direction of the tunnel body 1. The longitudinal water guiding ditch 7 is arranged on both sides of the axis of the tunnel body 1, and the longitudinal water guiding ditch 7 connects the circumferential water collection channel 6 and the V-shaped water guiding channel 2.

[0030] like Figure 1-2 As shown, in one specific embodiment, the drainage section further includes a permeable grid 8, which is disposed on the top side of the V-shaped water guide channel 2. The permeable grid 8 serves to divert and filter water, preventing debris from entering the water collection system and ensuring efficient drainage. The longitudinal water guide channel 7 has a V-shaped cross-section, and its wall is coated with an epoxy resin anti-seepage layer with a thickness of not less than 2 mm. In addition, a stainless steel filter screen is removably and washably installed in the circumferential water collection channel 6. The stainless steel filter screen has a pore size Φ of 2~3 mm, an installation inclination angle γ of 55°~65°, and a maintenance slide rail is provided on one side of the bottom of the stainless steel filter screen.

[0031] like Figure 1-2 As shown, in one specific embodiment, the drainage pipe 5 is laid overhead along the side wall of the tunnel body 1, and an electric butterfly valve is installed on the drainage pipe 5. The drainage pipe 5 is typically DN300. The overhead laying design of the drainage pipe 5 avoids direct contact between the pipe and the water accumulation at the bottom of the tunnel body 1, thereby reducing pipe wear and corrosion and improving the service life of the drainage system. The water collection wells 3 are spaced 500m apart, located at the lowest point of the tunnel axis, and spaced 500 meters apart. This arrangement ensures concentrated collection of water flow while reducing the risk of water accumulation.

[0032] In addition, the circumferential drainage channels 6 are arranged circumferentially along the inner wall of the tunnel body 1, with a spacing of L=5~8 meters. The circumferential drainage channels 6 can evenly guide the water flow to the longitudinal drainage ditch 7 and the collection well 3, effectively distributing the water flow load and improving the overall drainage efficiency. The longitudinal drainage ditch 7 is arranged on both sides of the axis of the tunnel body 1, with a bottom slope β≥2% and an inverted trapezoidal cross-section design. This design can increase the flow velocity of the water, avoid water stagnation, improve drainage efficiency, and ensure that the water flows smoothly to the collection well 3.

[0033] like Figure 1-2 As shown, in one specific embodiment, the slope angle α of the inclined arrangement of the tunnel body 1 is 5°~8°, the angle θ between the axial direction of the tunnel body 1 and the direction of the maximum principal stress of the surrounding rock is ≤30°, and the axial direction of the tunnel body 1 forms an acute angle of 15°~25° with the orientation of the dominant joint surface. Furthermore, the lining of the tunnel body 1 is made of steel fiber reinforced concrete, with a fiber content of 35~45 kg / m³, a lining thickness T of 250~400 mm, and satisfies T≥0.06D.

[0034] like Figure 1-2 As shown, in one specific embodiment, the start and stop of the submersible pump 4 is controlled by the PLC controller according to the set water level sensor signal; the at least two submersible pumps 4 include at least one main pump and at least one standby pump. When the water level h≥1.2m, the main pump is started; when the water level h≥1.5m, the standby pump is started; when the water level h≤0.5m, both the main pump and the standby pump are stopped.

[0035] In summary, through the above structural design, the self-draining underground tunnel structure based on the bearing capacity of the surrounding rock provided in this application embodiment can effectively improve the drainage capacity and overall stability of the self-draining underground tunnel, ensuring that the tunnel can operate safely and for a long time in a complex groundwater environment, reducing the occurrence of water damage, and also facilitating later maintenance and management.

[0036] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A self-draining underground tunnel structure based on the bearing capacity of surrounding rock, characterized in that, include: The tunnel body has its axis extending at an angle to the rock strata, and its cross-sectional profile is horseshoe-shaped. The drainage section includes a V-shaped water guide channel and multiple water collection wells. The V-shaped water guide channel is located at the bottom of the tunnel body and extends along the axial direction of the tunnel body. The multiple water collection wells are arranged at preset intervals along the axial direction of the tunnel body. At least two submersible pumps are installed in each water collection well, and the outlet end of each submersible pump is connected to a drainage pipe. A water guiding section is disposed on the wall of the tunnel body. The water guiding section is connected to the V-shaped water guiding channel and can guide water from the wall of the tunnel body into the V-shaped water guiding channel.

2. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to claim 1, characterized in that, The water guiding section includes a circumferential water collection channel and a longitudinal water guiding ditch. The circumferential water collection channel is arranged circumferentially along the inner wall of the tunnel body. There are multiple circumferential water collection channels, which are spaced apart along the axial direction of the tunnel body. The longitudinal water guiding ditch is arranged on both sides of the tunnel body axis, and the longitudinal water guiding ditch connects the circumferential water collection channel and the V-shaped water guiding channel.

3. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to claim 2, characterized in that, The drainage section also includes a permeable grid, which is disposed on the top side of the V-shaped water guide channel; the longitudinal water guide channel has a V-shaped cross-section and the wall of the longitudinal water guide channel is coated with an epoxy resin anti-seepage layer, the thickness of which is not less than 2mm.

4. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to claim 2, characterized in that, The circumferential water collection tank is equipped with a removable and washable stainless steel filter screen. The stainless steel filter screen has a hole diameter Φ of 2~3mm, an installation tilt angle γ of 55°~65°, and a maintenance slide rail is provided on one side of the bottom of the stainless steel filter screen.

5. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to any one of claims 2-4, characterized in that, The drainage pipe is laid overhead along the side wall of the tunnel body, and an electric butterfly valve is installed on the drainage pipe; the interval between the water collection wells is 500m, the interval between the circumferential water collection channels is 5~8m, the bottom slope β of the longitudinal water guide ditch is ≥2%, and the cross-sectional shape of the longitudinal water guide ditch is an inverted trapezoid.

6. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to any one of claims 1-4, characterized in that, The slope angle α of the inclined arrangement of the main tunnel body is 5°~8°, the angle θ between the axial direction of the main tunnel body and the direction of the maximum principal stress of the surrounding rock is ≤30°, and the axial direction of the main tunnel body forms an acute angle of 15°~25° with the orientation of the dominant joint surface.

7. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to claim 6, characterized in that, The tunnel lining is made of steel fiber reinforced concrete, with a fiber content of 35~45 kg / m³, a lining thickness T of 250~400 mm, and T≥0.06D.

8. The self-draining underground tunnel structure based on the bearing capacity of surrounding rock according to any one of claims 1-4 or 7, characterized in that, The operation of the submersible pump is controlled by the PLC controller based on the water level sensor signal. The submersible pump includes at least one main pump and at least one standby pump. The main pump is started when the water level h ≥ 1.2m, the standby pump is started when the water level h ≥ 1.5m, and both the main pump and the standby pump are stopped when the water level h ≤ 0.5m.

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