Inverted-arch-free tunnel and inverted-arch-free tunnel construction method

Abstract

The invention provides an inverted-arch-free tunnel and an inverted-arch-free tunnel construction method, and relates to the technical field of tunnel construction. The inverted-arch-free tunnel comprises a protection structure and a bottom supporting structure. The protection structure is in an arch shape, a bottom supporting structure is connected between the two sides of the bottom of the protection structure, the bottom supporting structure is in a flat plate shape, and a cable trench extending in the extending direction of the inverted-arch-free tunnel is formed in the joint of the bottom supporting structure and the protection structure. The interior of the cable trench is provided with a separator to divide the interior of the cable trench into a first space and a second space, the first space is higher than the bottom supporting structure and is used for accommodating a cable, and the second space is lower than the bottom supporting structure and forms a drainage ditch; water passing holes are formed in the side wall of the cable trench and the partition piece, and the drainage ditch is used for receiving water flow from the bottom supporting structure through the water passing holes. According to the inverted-arch-free tunnel, the inverted arch can be replaced by the flat-plate-shaped bottom supporting structure, so that the inverted arch does not need to be excavated, and tunnel collapse caused by disengagement of arch feet of the protection structure is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a non-inverted tunnel and a non-inverted tunnel construction method. Background Art

[0002] Tunnel construction usually includes protection construction and invert construction, which are carried out successively. Protection construction refers to the construction of arched primary support structure and secondary lining structure in the tunnel to form a composite protection, and invert construction refers to the construction of a reverse arch structure at the bottom of the tunnel to form an invert.

[0003] Among them, the invert is a reverse arch structure set at the bottom of the tunnel to improve the stress conditions of the upper support structure of the tunnel. It can not only effectively transfer the stratum pressure above the tunnel to the underground through the tunnel side wall structure or the load on the road surface, but also effectively resist the reaction force from the stratum below the tunnel. Therefore, the invert is an important part of the tunnel ring, which makes the tunnel as a whole form a horseshoe circle, effectively disperses rock stress, and increases tunnel stability.

[0004] However, the invert will penetrate the primary support structure and the secondary lining structure. When the surrounding rock conditions in the tunnel environment are poor, the excavation of the invert is the most dangerous construction stage, which can easily cause the steel arch frame in the secondary lining structure to become empty, thereby causing the tunnel to collapse. Summary of the invention

[0005] The purpose of the present invention is to provide a tunnel without an invert and a method for constructing a tunnel without an invert, so as to alleviate the technical problem in the prior art that the invert of the tunnel will penetrate the primary support structure and the secondary lining structure, and when the surrounding rock conditions in the tunnel environment are poor, the excavation of the invert is the most dangerous construction stage, which can easily cause the steel arch frame in the secondary lining structure to become empty, thereby causing the tunnel to collapse.

[0006] In a first aspect, the present invention provides a non-inverted arch tunnel, comprising a protective structure and a bottom support structure;

[0007] The protective structure is in an arch shape, the bottom supporting structure is connected between two sides of the bottom of the protective structure, and the bottom supporting structure is in a flat plate shape;

[0008] A cable trench extending along the extending direction of the non-inverted arch tunnel is provided at the connection between the bottom supporting structure and the protective structure, and a partition is provided inside the cable trench to divide the inside of the cable trench into a first space and a second space, wherein the first space is higher than the bottom supporting structure and is used to accommodate cables, and the second space is lower than the bottom supporting structure and forms a drainage trench;

[0009] Water holes are provided on the side walls of the cable trench and on the partition, and the drainage trench is used to receive water flow from the bottom supporting structure through the water holes.

[0010] In an optional embodiment, a cable trench is further provided at the connection between the bottom supporting structure and the bottom side of the protective structure, and the cable trench extends along the extension direction of the non-inverted arch tunnel. A partition is provided inside the cable trench to divide the cable trench into a first space located above and a second space located below, and the first space is used to accommodate cables. The partition is provided with a water hole, and the second space forms the drainage ditch.

[0011] In an optional embodiment, it also includes a blind ditch filled with stones, the blind ditch is arranged below the bottom supporting structure, the bottom of the protective structure is provided with a drainage port connected to the internal drainage channel thereof, and the blind ditch is connected to the drainage port.

[0012] In an optional embodiment, a blind pipe is further included, wherein the blind pipe is arranged below the bottom supporting structure and the blind pipe is connected to the drain port.

[0013] In an optional embodiment, the anchoring structure includes an anchor rod group, which includes a plurality of anchor rods spaced apart along the extension direction of the non-inverted arch tunnel, and the anchor rod group is provided below the bottom support structure at least close to the bottom side edge of the protective structure.

[0014] In an optional embodiment, the anchoring structure further includes a reinforcement body, and the material of the reinforcement body is a colloidal material that can solidify into a solid;

[0015] The anchor rod is hollow and the rod body of the anchor rod is provided with a slurry outlet hole communicated with the internal space thereof, and the reinforcement body is covered outside a part of the anchor rod group or outside the entire anchor rod group.

[0016] In an optional embodiment, a transverse support frame is further included, and the transverse support frame is arranged below the bottom support structure, and the bottom side of each of the protective structures is connected to the transverse support frame.

[0017] In a second aspect, the present invention provides a method for constructing a non-inverted arch tunnel, which is used to construct the non-inverted arch tunnel described in any one of the aforementioned embodiments, comprising:

[0018] S1: excavating a tunnel space and constructing the protective structure in the tunnel space;

[0019] S2: constructing the bottom support structure at the bottom of the tunnel space, fixing the two sides of the bottom of the protective structure to the two sides of the bottom support structure respectively, and constructing the drainage ditch at the connection between the bottom support structure and the bottom side of the protective structure.

[0020] In an optional embodiment, the following steps are further included after step S1:

[0021] S10: dividing a plurality of anchor rods in the anchoring structure into at least one anchor rod group, and making each of the anchor rod groups include a plurality of anchor rods;

[0022] S11: installing the anchor rod group at a position at the bottom ground of the tunnel space at least close to the bottom side edge of the protective structure, and making the plurality of anchor rods in the anchor rod group distributed at intervals along the extension direction of the non-inverted arch tunnel.

[0023] In an optional implementation, the following steps are further included after step S11:

[0024] S12: After the anchor rod group is installed, a colloidal material that can solidify into a solid is injected into the anchor rods in a partial anchor rod group or all anchor rod groups through the grouting holes on the anchor rods, and the colloidal material is allowed to flow into the soil on the surrounding side through the grouting holes on the anchor rods.

[0025] The non-inverted arch tunnel provided by the present invention comprises a protective structure and a bottom support structure; the protective structure is in an arch shape, and the bottom support structure is connected between the two sides of the bottom of the protective structure, and the bottom support structure is in a flat plate shape; a cable trench extending along the extension direction of the non-inverted arch tunnel is provided at the connection between the bottom support structure and the protective structure, and a partition is provided inside the cable trench to divide the inside of the cable trench into a first space and a second space, the first space is higher than the bottom support structure and is used to accommodate cables, and the second space is lower than the bottom support structure and forms a drainage ditch; water holes are provided on the side walls of the cable trench and on the partition, and the drainage ditch is used to receive water flow from the bottom support structure through the water holes. In the process of constructing the non-inverted arch tunnel provided by the present invention, the tunnel hole can be excavated first, and then an arched primary support structure and a secondary lining structure can be constructed in the tunnel hole to form a protective structure. Then, a flat bottom support structure can be constructed on the ground inside the tunnel hole, and the two sides of the bottom support structure are connected to the two sides of the bottom of the protective structure respectively. At this time, the bottom support structure and the soil below it can support the bottom side (arch foot) of the protective structure, improve the deformation resistance of the arch foot of the protective structure, thereby improving the stress conditions of the protective structure and ensuring the stability of the overall structure of the non-inverted arch tunnel. When constructing the bottom support structure, a cable trench can also be constructed at the connection between the bottom support structure and the bottom side of the protective structure, and then a separator is installed in the cable trench to divide the internal space of the cable trench into a first space and a second space, so that the first space is used to accommodate the cables required for the tunnel, and the second space is used as a drainage ditch to discharge the moisture inside the tunnel. In order to allow the moisture in the tunnel to flow into the drainage ditch, the second space needs to be lower than the bottom support structure, and water holes need to be set on the side walls and separators of the cable trench. Therefore, after the moisture in the tunnel gathers on the bottom support structure, it can flow into the drainage ditch through the water holes and then be discharged through the drainage ditch.

[0026] Compared with the prior art, the inverted arch tunnel provided by the present invention can replace the inverted arch by a flat bottom support structure, so there is no need to excavate the inverted arch after the construction of the protective structure is completed, and the arch foot of the protective structure will not be emptied, which effectively reduces the risk of tunnel collapse. In addition, since the inverted arch tunnel provided by the present invention does not need to excavate the inverted arch during the construction process, and the bottom support structure is in the shape of a flat plate, during the construction process, construction vehicles and other equipment can directly walk on the ground at the bottom of the tunnel or on the top of the bottom support structure, without the need to build temporary passages such as trestles, effectively improving construction efficiency and saving construction costs. In addition, compared with the existing tunnel construction method of setting a drainage ditch on one side of the cable trench, the inverted arch tunnel provided by the present invention divides a second space at the bottom of the cable trench as a drainage ditch through a separator, which can make full use of the cable trench space, thereby saving the internal space of the tunnel and improving construction efficiency.

[0027] The non-inverted arch tunnel construction method provided by the present invention is used to construct the above-mentioned non-inverted arch tunnel, including: S1: excavating the tunnel space and constructing the protective structure in the tunnel space; S2: constructing the bottom support structure at the bottom of the tunnel space, fixing the bottom sides of the protective structure to the two sides of the bottom support structure respectively, and constructing the drainage ditch at the connection between the bottom support structure and the bottom side of the protective structure. The non-inverted arch tunnel construction method provided by the present invention can also use the bottom support structure to replace the inverted arch, so there is no need to excavate the inverted arch, and the arch foot of the protective structure will not be emptied to cause tunnel collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of a tunnel without an invert provided by an embodiment of the present invention;

[0030] Figure 2 for Figure 1 The main view of the tunnel without invert in the figure;

[0031] Figure 3 for Figure 1 A top view of the tunnel without an invert in the figure;

[0032] Figure 4 for Figure 1 Schematic diagram of the stress state of the non-inverted arch tunnel;

[0033] Figure 5Another schematic structural diagram of a tunnel without an invert provided by an embodiment of the present invention;

[0034] Figure 6 for Figure 5 The main view of the tunnel without invert in the figure;

[0035] Figure 7 for Figure 5 A top view of the tunnel without an invert in the figure;

[0036] Figure 8 A schematic diagram of the stress state of a non-inverted arch tunnel provided by an embodiment of the present invention;

[0037] Fig. 9 Another structural schematic diagram of a tunnel without an inverted arch provided by an embodiment of the present invention;

[0038] Fig.10 for Fig. 9 The main view of the tunnel without invert in the figure;

[0039] Fig.11 for Fig. 9 A top view of the tunnel without an invert in the figure;

[0040] Fig.12 for Fig. 9 Schematic diagram of the stress state of the non-inverted arch tunnel.

[0041] Icons: 1-protection structure; 10-primary support structure; 11-secondary lining structure; 12-steel arch frame; 13-reinforcement anchor; 2-bottom support structure; 3-anchor structure; 30-anchor rod group; 300-anchor rod; 31-reinforcement body; 4-cable trench; 5-blind trench; 6-blind pipe; 7-lateral support frame. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0045] Example:

[0046] like Figure 1 and Figure 2 As shown, the non-inverted arch tunnel provided in this embodiment includes a protective structure 1 and a bottom supporting structure 2; the protective structure 1 is arched, and the bottom supporting structure 2 is connected between the two sides of the bottom of the protective structure 1, and the bottom supporting structure 2 is flat; a cable trench 4 extending along the extension direction of the non-inverted arch tunnel is provided at the connection between the bottom supporting structure 2 and the protective structure 1, and a partition is provided inside the cable trench 4 to divide the inside of the cable trench 4 into a first space and a second space, the first space is higher than the bottom supporting structure 2 and is used to accommodate cables, and the second space is lower than the bottom supporting structure 2 and forms a drainage ditch; water holes are provided on the side walls of the cable trench 4 and on the partitions, and the drainage ditch is used to receive water flow from the bottom supporting structure through the water holes.

[0047] In the process of constructing the non-inverted arch tunnel provided by this embodiment, the tunnel hole can be excavated first, and then the arched primary support structure 10 and the secondary lining structure 11 can be constructed in the tunnel hole to form the protective structure 1. Then, a flat bottom support structure 2 can be constructed on the ground in the tunnel hole, and the two sides of the bottom support structure 2 are connected to the two sides of the bottom of the protective structure 1 respectively. At this time, the bottom support structure 2 and the soil below it can support the bottom side (arch foot) of the protective structure 1, improve the deformation resistance of the arch foot of the protective structure 1, thereby improving the stress condition of the protective structure 1 and ensuring the stability of the overall structure of the non-inverted arch tunnel. When constructing the bottom support structure, a cable trench 4 can also be constructed at the connection between the bottom support structure 2 and the bottom side of the protective structure 1, and then a partition can be installed in the cable trench 4 to divide the internal space of the cable trench 4 into a first space and a second space, so that the first space is used to accommodate the cables required for the tunnel, and the second space is used as a drainage ditch to discharge the moisture inside the tunnel. In order to allow the water in the tunnel to flow into the drainage ditch, the second space needs to be lower than the bottom support structure 2, and water holes need to be set on the side walls and separators of the cable trench. Figure 1 The water flows into the gutter through the water holes in the direction of the arrow shown, and then is discharged through the gutter.

[0048] Among them, the two ends of the drainage ditch can be connected with the external drainage channel. In order to make the water on the bottom supporting structure 2 easily flow to the drainage ditch, in this embodiment, the top of the bottom supporting structure 2 is preferably an inclined surface, and from the top of the bottom supporting structure 2, from the position of its central axis to the side of the bottom supporting structure 2, it is inclined downward. At this time, the top of the drainage ditch needs to be lower than the side of the bottom supporting structure 2. Therefore, the inclined surface will play a diversion role, so that the accumulated water inside the tunnel falling on the bottom supporting structure 2 can easily flow to the drainage ditch, and then be discharged through the drainage ditch.

[0049] Compared with the prior art, the inverted arch tunnel provided in this embodiment can replace the inverted arch with a flat bottom supporting structure 2, thereby eliminating the need to excavate the inverted arch after the construction of the protective structure 1 is completed, and will not cause the arch foot of the protective structure 1 to become empty, thereby effectively reducing the risk of tunnel collapse.

[0050] Furthermore, since the inverted arch tunnel provided in this embodiment does not require excavation of an inverted arch during construction, and the bottom supporting structure 2 is in the shape of a flat plate, during construction, construction vehicles and other equipment can directly travel on the ground at the bottom of the tunnel or on the top of the bottom supporting structure 2 without the need to build temporary passages such as trestles, thereby effectively improving construction efficiency and saving construction costs.

[0051] In addition, in the existing tunnel construction process, a drainage ditch is usually set up on one side of the cable trench, which will additionally occupy the surrounding rock space around the tunnel. Figure 1 , Figure 5 and Fig. 9 As shown, in this embodiment, a second space is divided at the bottom of the cable trench 4 by a separator as a drainage trench, which can fully utilize the space of the cable trench 4, thereby saving the internal space of the tunnel and improving construction efficiency.

[0052] It should be noted that the protective structure 1 in the non-inverted arch tunnel provided in this embodiment is the same as the arch protection in the existing tunnel, and can be a composite protection formed by the primary support structure 10 and the secondary lining structure 11, wherein the secondary lining structure 11 includes a steel arch frame 12. Figure 1 -like Figure 3 As shown, before constructing the primary support structure 10, a reinforcement anchor 13 can be driven into the soil at the arched side wall of the tunnel, and then the primary support structure 10 and the secondary lining structure 11 are successively constructed at the arched side wall of the tunnel hole, and the ends of the reinforcement anchor 13 exposed in the tunnel hole are covered by the primary support structure 10 and the secondary lining structure 11. Since both the primary support structure 10 and the secondary lining structure 11 are prior arts, their specific structures and construction processes are not described in detail here.

[0053] It should also be noted that when the surrounding rock conditions in the tunnel environment are good, the bottom support structure 2 can be directly constructed on the ground at the tunnel without reinforcing the soil. When the surrounding rock conditions are poor, in order to effectively ensure the stability of the tunnel structure, such as Figure 1 and Figure 2 As shown, an anchoring structure 3 may be further provided below the bottom supporting structure 2 , with one end of the anchoring structure 3 connected to the bottom support and the other end extending into the soil below the bottom supporting structure 2 .

[0054] During the construction of the non-inverted arch tunnel provided in this embodiment, after the protective structure 1 is constructed, an anchoring structure 3 can be firstly set in the soil surrounding rock on the ground inside the tunnel hole. At this time, the anchoring structure 3 can reinforce the soil surrounding rock, effectively improving the structural stability and supporting strength of the soil surrounding rock, and then a flat bottom supporting structure 2 is constructed on the ground inside the tunnel hole, and the two sides of the bottom supporting structure 2 are respectively connected to the two sides of the bottom of the protective structure 1, and the bottom of the bottom supporting structure 2 is connected to the anchoring structure 3. At this time, the anchoring structure 3, the bottom supporting structure 2 and the protective structure 1 are connected as a whole, the anchoring structure 3 can support the bottom supporting structure 2, effectively ensuring the structural stability of the bottom supporting structure 2, and the bottom supporting structure 2 can support the bottom side (arch foot) of the protective structure 1, further effectively improving the anti-deformation ability of the arch foot of the protective structure 1, thereby effectively improving the stress condition of the protective structure 1 and ensuring the stability of the overall structure of the non-inverted arch tunnel.

[0055] It can be seen that when the surrounding rock conditions are poor, the inverted arch tunnel provided in this embodiment can also replace the inverted arch by cooperating with the bottom support structure 2 and the anchoring structure 3. Similarly, there is no need to excavate the inverted arch after the construction of the protective structure 1 is completed, which will not cause the arch foot of the protective structure 1 to be emptied, effectively reducing the risk of tunnel collapse.

[0056] Further, such as Figure 1-Figure 3 , Figure 5-Figure 7 and Figure 9-11 As shown, the anchoring structure 3 includes an anchor rod group 30, which includes a plurality of anchor rods 300 spaced apart along the extension direction of the non-inverted arch tunnel. The anchor rod group 30 is provided below the bottom supporting structure 2 at least close to the bottom side of the protective structure 1.

[0057] Since the arch foot of the protective structure 1 is a weak position, an anchor rod group 30 is provided below the bottom supporting structure 2 at least close to the bottom side of the protective structure 1 to effectively ensure the supporting strength of the bottom supporting structure 2 to the protective structure 1 .

[0058] It should be noted that there is no limit to the number of anchor rod groups 30, which can be selected according to the surrounding rock conditions in the construction environment.

[0059] like Figure 1 and Figure 2As shown, when the surrounding rock conditions are good, two anchor rod groups 30 can be respectively provided at the positions on both sides of the bottom of the bottom support structure 2 close to the protective structure 1. At this time, the overall stress state of the non-inverted arch tunnel is as follows: Figure 4 As shown, the protective structure 1 and the bottom supporting structure 2 bear the pressure from the surrounding rock of the soil on the side of the tunnel. Since the surrounding rock will generate an upward thrust at the connection between the bottom side of the protective structure 1 and the bottom supporting structure 2, a bending moment is formed there, which causes the arch foot to rotate. Therefore, at this time, the connection between the protective structure 1 and the bottom supporting structure 2 also needs to bear a bending moment, which plays a role of anti-arch.

[0060] It should also be noted that in order to improve the anchoring strength of the anchor rod group 30 in the soil and prevent the anchor rod group 30 from automatically drilling into the soil and becoming ineffective, Figure 1 and Figure 2 As shown, each anchor rod 300 in the anchor rod group 30 can be arranged tilted, and the anchor rod 300 is tilted from one end close to the bottom supporting structure 2 to the other end in a direction away from the central axis of the tunnel.

[0061] When the surrounding rock conditions are average, in order to further improve the structural stability of the non-inverted arch tunnel, such as Figure 5 , Figure 6 , Fig. 9 and Fig.10 As shown, the anchoring structure 3 also includes a reinforcement body 31, the material of the reinforcement body 31 is a colloidal material that can solidify into a solid; the anchor rod 300 is hollow and the rod body of the anchor rod 300 is provided with a slurry outlet hole connected to its internal space, and the reinforcement body 31 is covered outside the partial anchor rod group 30 or the entire anchor rod group 30.

[0062] When constructing the anchor structure 3, the colloid material such as mortar can be used to first drive the anchor rods 300 in all the anchor rod groups 30 into the soil, and then inject the mortar or other colloid material into the hollow anchor rods 300. During the grouting process, the colloid material will flow out through the grouting holes on the anchor rods 300 into the soil around the anchor rods 300, and the reinforcement body 31 can be formed after the colloid material solidifies. At this time, the reinforcement body 31 can consolidate the anchor rod 300 and the soil around it, which can not only improve the stability of the anchor rod 300 in the soil, but also improve the reinforcement effect of the anchor structure 3 on the surrounding rock.

[0063] In order to facilitate the anchor rod 300 to drill into the soil and to facilitate the injection of colloid material into the anchor rod 300, the end of the anchor rod 300 drilled into the soil may be a pointed end, and the other end may be provided with a grouting hole.

[0064] It should be noted that the reinforcement body 31 can be covered on the outside of a part of the anchor rod group 30 or the outside of the entire anchor rod group 30 according to the surrounding rock conditions.

[0065] When the surrounding rock conditions are normal, such as Figure 5 and Figure 6 As shown, only two anchor rod groups 30 can be provided at positions on both sides of the bottom of the protective structure 1 below the bottom support structure 2, and the anchor rods 300 in each anchor rod group 30 are inclined, and then the colloid material is injected into the anchor rods 300 in all the anchor rod groups 30. After the colloid material solidifies, an inclined reinforcement body 31 is formed at positions on both sides of the bottom of the protective structure 1, which effectively improves the overall structural stability of the non-inverted tunnel.

[0066] When the surrounding rock conditions are poor and the karst cave porosity in the surrounding rock is large, the anchor rod groups 30 can be fully distributed at the position below the bottom support structure 2. At this time, multiple anchor rod groups 30 are distributed in sequence along the width direction of the tunnel, and the anchor rods 300 in each anchor rod group 30 can be set vertically. Then, the anchor rod groups 30 close to the bottom of the protective structure 1 can be selected as grouting anchor rod groups 30, and colloidal material can be injected into each anchor rod 300 therein, that is, colloidal material is injected into the anchor rods 300 of the local anchor rod group 30. After the colloidal material solidifies, a vertical reinforcement body 31 will be formed at the positions close to the bottom of the protective structure 1 on both sides. At this time, the reinforcement body 31 can be used as a retaining wall, and its overall stress state is as follows: Figure 8 As shown, the protective structure 1 and the bottom support structure 2 bear the pressure from the soil and rock surrounding the tunnel, the reinforcement body 31 effectively resists the lateral squeezing force of the surrounding rock, and the reinforcement bodies 31 on both sides can protect the rock and soil sandwiched therein, thereby effectively improving the overall structural stability of the non-inverted arch tunnel.

[0067] When the surrounding rock conditions are poor, for example, the surrounding rock is relatively broken, and is in the fifth or sixth level of surrounding rock conditions, the anchor rod group 30 can also be fully distributed below the bottom support structure 2, and multiple anchor rod groups 30 are distributed in sequence along the width direction of the tunnel, and the anchor rods 300 in each anchor rod group 30 are vertically arranged. However, in order to further improve the overall structural stability of the non-inverted arch tunnel, such as Fig. 9 and Fig.10 As shown, at this time, the colloid material can be injected into the anchor rods 300 of all the anchor rod groups 30. When the colloid material solidifies, an integral reinforcement body 31 will be formed in the soil below the bottom support structure 2. At this time, the reinforcement body 31 can be used as a rock wall, and its overall stress state is as follows: Fig.12 As shown, the protective structure 1 and the bottom support structure 2 bear the pressure from the soil and surrounding rock around the tunnel, and the reinforcement body 31 can effectively resist the squeezing pressure from all directions of the surrounding rock, which can further effectively improve the overall structural stability of the non-inverted arch tunnel.

[0068] like Figure 5 and Fig. 9As shown, the non-inverted arch tunnel provided in this embodiment may also include a blind ditch 5 filled with stones, the blind ditch 5 is arranged below the bottom supporting structure 2, the bottom of the protective structure 1 is provided with a drainage outlet connected to the drainage channel inside it, and the blind ditch 5 is connected to the drainage outlet.

[0069] Both ends of the blind ditch 5 can also be connected to the external drainage channel. During the construction process, water will penetrate into the gap between the primary support structure 10 and the secondary lining structure 11 of the protective structure 1. After this part of the water flows to the drain outlet through the drainage channel under the action of gravity, it can also flow to the blind ditch 5 along the gap under the bottom supporting structure 2, and then be discharged to the outside through the blind ditch 5.

[0070] Among them, since the blind ditch 5 is filled with stones, the blind ditch 5 still has sufficient strength, and the structural strength of the surrounding rock and soil will not be affected by excavating the blind ditch 5. In addition, since the gaps between the stones are large, the stones will not affect the drainage process.

[0071] It can be seen that the non-inverted arch tunnel provided in this embodiment can realize the internal drainage of the tunnel through the drainage ditch, and the external drainage of the tunnel through the blind ditch 5. Compared with the existing tunnels, the drainage ditch at the invert is used to discharge the internal and external water. It can not only fully ensure the stability of the surrounding rock structure, but also improve the drainage effect and efficiency.

[0072] Further, such as Figure 1 and Figure 2 As shown, the non-inverted arch tunnel provided in this embodiment may further include a blind pipe 6, which is arranged below the bottom supporting structure 2 and is connected to the drainage outlet.

[0073] Both ends of the blind pipe 6 can also be connected to the external drainage channel, and the pipe body of the blind pipe 6 can be provided with a penetration hole, and the blind pipe 6 is connected to the drainage port through the penetration hole. When the water between the primary support structure 10 and the secondary lining structure 11 flows to the drainage port through the drainage channel, it can also flow to the blind pipe 6 along the gap under the bottom support structure 2, and then be discharged to the outside through the blind pipe 6.

[0074] The blind pipe 6 and the blind ditch 5 can be used in combination. A smaller portion of the water flowing to the drain outlet can be discharged through the blind pipe 6, while a larger portion can be discharged through the blind ditch 5, thereby further optimizing the drainage effect and improving the drainage efficiency.

[0075] The diameter of the blind pipe 6 is usually small, so the arrangement of the blind pipe 6 will not damage the soil state. For example, the diameter of the blind pipe 6 can usually be 3-10 cm.

[0076] Furthermore, the diameter of the blind tube 6 may be 5 cm.

[0077] In order to ensure the stability of the soil at the blind pipe 6 supporting the bottom supporting structure 2, the blind pipe 6 can be a tube woven from materials such as chemical fibers, or the inside of the blind pipe 6 can be filled with water-permeable particles.

[0078] like Figure 1 As shown, the non-inverted arch tunnel provided in this embodiment may further include a transverse support frame 7, which is arranged below the bottom support structure 2, and the bottom side of each protective structure 1 is connected to the transverse support frame 7.

[0079] The transverse support frame 7 is suitable for construction conditions with general or poor surrounding rock conditions. During the construction process, the transverse support frame 7 can be first installed on the ground in the tunnel, and then the anchor structure 3 is driven into the soil, and finally the bottom support structure 2 is constructed.

[0080] The transverse support frame 7 can be connected to the arch foot of the steel arch frame 12 in the protective structure 1. In order to facilitate the connection of the bottom side of the protective structure 1 with the transverse support frame 7, the construction process of the transverse support frame 7 can be carried out simultaneously with the construction process of the protective structure 1. At this time, the transverse support frame 7 can not only temporarily reinforce the protective structure 1 and reduce the disturbance to the surrounding rock, but also link the construction process of the primary support structure 10 and the construction process of the secondary lining structure 11, effectively improving the construction efficiency.

[0081] In addition, the transverse support frame 7 can also provide a transverse thrust to the arch foot of the protective structure 1, further improving the anti-deformation ability of the arch foot of the protective structure 1. In addition, the transverse support frame 7 can also reinforce the lower surrounding rock, further improving the stability of the bottom support structure 2.

[0082] The transverse support frame 7 may be a steel frame, and the bottom support structure 2 may be a concrete structure or a reinforced concrete structure.

[0083] This embodiment also provides a method for constructing a tunnel without an invert arch, which is used to construct the tunnel without an invert arch, comprising:

[0084] Step S1: excavating a tunnel space and constructing a protective structure 1 in the tunnel space;

[0085] Step S2: construct a bottom support structure 2 at the bottom of the tunnel space, fix the bottom sides of the protective structure 1 to the bottom sides of the bottom support structure 2 respectively, and construct a drainage ditch at the connection between the bottom support structure 2 and the bottom side of the protective structure 1.

[0086] Compared with the prior art, the invert-free tunnel construction method provided in this embodiment can also use a flat bottom support structure 2 to replace the invert in step S2, thereby eliminating the need to excavate the invert and causing the arch foot of the protective structure 1 to be emptied and cause tunnel collapse.

[0087] Furthermore, the non-inverted arch tunnel construction method provided in this embodiment further includes the following steps after step S1:

[0088] Step S10: Divide the multiple anchor rods 300 in the anchor structure 3 into at least one anchor rod group 30, and make each anchor rod group 30 include multiple anchor rods 300;

[0089] Step S11: An anchor group 30 is installed at a position at least close to the bottom side of the protective structure 1 at the bottom ground of the tunnel space, and multiple anchors 300 in the anchor group 30 are distributed at intervals along the extension direction of the non-inverted arch tunnel.

[0090] The anchor rods 300 in the anchor rod group 30 are used to reinforce the surrounding rock. Since the position close to the bottom side of the protective structure 1 is a weak area, the overall stability of the non-inverted arch tunnel can be effectively improved by only installing the anchor rod group 30 there.

[0091] In order to improve the anchoring ability of the anchor rod 300, the anchor rod 300 can be arranged tilted, and the anchor rod 300 is tilted from one end close to the bottom supporting structure 2 to the other end in a direction away from the central axis of the tunnel.

[0092] Furthermore, step S2 further includes:

[0093] Step S12: After the anchor rod group 30 is installed, a colloidal material that can solidify into a solid is injected into the anchor rods 300 in a partial anchor rod group 30 or all the anchor rod groups 30 through the grouting holes on the anchor rods 300, and the colloidal material is allowed to flow into the soil around it through the grouting holes on the anchor rods 300.

[0094] The colloidal material is used to form a reinforcement body 31 after solidification, which can not only further improve the anchoring capacity of the anchoring structure 3 and the surrounding rock, but also improve the supporting stability of the anchoring structure 3 to the bottom supporting structure 2, thereby further effectively improving the overall stability of the non-inverted arch tunnel.

[0095] Step S12 can be performed based on the surrounding rock conditions, specifically:

[0096] When the surrounding rock conditions are normal, the anchor rod group 30 can be set only at the position close to the bottom side of the protective structure 1, and the anchor rod 300 can be set inclined. At this time, in step S22, a colloidal material that can solidify into a solid can be injected into the anchor rods 300 in all the anchor rod groups 30. After the colloidal material solidifies, Figure 1 As shown, two inclined reinforcement bodies 31 may be formed below the bottom supporting structure 2 .

[0097] When the surrounding rock conditions are poor and the porosity of the karst caves in the surrounding rock is large, the anchor rod groups 30 can be fully distributed under the bottom supporting structure 2, and multiple anchor rod groups 30 are distributed along the width of the tunnel and the anchor rods 300 are arranged vertically. At this time, in step S22, only the anchor rod groups 30 close to the bottom sides of the protective structure 1, that is, the anchor rods 300 in the local anchor rod groups 30, can be injected with colloidal material that can solidify into a solid. After the colloidal material solidifies, two vertical retaining walls can be formed under the bottom supporting structure 2.

[0098] When the surrounding rock conditions are poor, such as in a soft soil layer, the anchor rod group 30 can also be fully distributed under the bottom support structure 2, and multiple anchor rod groups 30 are distributed along the width direction of the tunnel, and the anchor rods 300 are arranged vertically. At this time, in step S22, a colloidal material that can solidify into a solid can be injected into the anchor rods 300 in all the anchor rod groups 30. After the colloidal material solidifies, Fig. 9 As shown, a vertical rock wall can be formed below the bottom support structure 2 .

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tunnel without an invert, characterized in that: It comprises a protective structure (1) and a bottom supporting structure (2); The protective structure (1) is in an arch shape, the bottom support structure (2) is connected between two sides of the bottom of the protective structure (1), and the bottom support structure (2) is in a flat plate shape; A cable trench (4) extending along the extension direction of the non-inverted arch tunnel is provided at the connection between the bottom supporting structure (2) and the protective structure (1), and a partition is provided inside the cable trench (4) to divide the inside of the cable trench (4) into a first space and a second space, wherein the first space is higher than the bottom supporting structure (2) and is used to accommodate cables, and the second space is lower than the bottom supporting structure (2) and forms a drainage trench; Water holes are provided on the side walls of the cable trench (4) and on the partition, and the drainage trench is used to receive water flow from the bottom support structure through the water holes.

2. The non-inverted arch tunnel according to claim 1, characterized in that: It also includes a blind ditch (5) filled with stones, the blind ditch (5) is arranged below the bottom supporting structure (2), the bottom of the protective structure (1) is provided with a drainage port connected to the drainage channel inside the protective structure (1), and the blind ditch (5) is connected to the drainage port.

3. The non-inverted arch tunnel according to claim 2, characterized in that: It also comprises a blind pipe (6), wherein the blind pipe (6) is arranged below the bottom supporting structure (2), and the blind pipe (6) is connected to the drainage port.

4. The non-inverted arch tunnel according to any one of claims 1 to 3, characterized in that: An anchoring structure (3) is provided below the bottom support structure (2), and one end of the anchoring structure (3) is connected to the bottom support, while the other end extends into the soil below the bottom support structure (2).

5. The non-inverted arch tunnel according to claim 4, characterized in that: The anchoring structure (3) comprises an anchor rod group (30), wherein the anchor rod group (30) comprises a plurality of anchor rods (300) spaced apart and distributed along the extension direction of the non-inverted arch tunnel, and the anchor rod group (30) is provided at a position below the bottom supporting structure (2) at least close to the bottom side edge of the protective structure (1).

6. The non-inverted arch tunnel according to claim 5, characterized in that: The anchoring structure (3) further comprises a reinforcing body (31), wherein the reinforcing body (31) is made of a colloidal material that can solidify into a solid; The anchor rod (300) is hollow and the rod body of the anchor rod (300) is provided with a slurry outlet hole communicating with the internal space thereof; the reinforcement body (31) is wrapped around the outside of a part of the anchor rod group (30) or the outside of the entire anchor rod group (30).

7. The non-inverted arch tunnel according to any one of claims 1 to 3, characterized in that: It also comprises a transverse support frame (7), which is arranged below the bottom support structure (2), and the bottom side edge of each protective structure (1) is connected to the transverse support frame (7).

8. A method for constructing a non-inverted arch tunnel, used for constructing the non-inverted arch tunnel according to any one of claims 1 to 7, characterized in that: include: S1: excavating a tunnel space and constructing the protective structure (1) in the tunnel space; S2: constructing the bottom support structure (2) at the bottom of the tunnel space, fixing the two sides of the bottom of the protective structure (1) to the two sides of the bottom support structure (2) respectively, and constructing the drainage ditch at the connection between the bottom support structure (2) and the bottom side of the protective structure (1).

9. The method for constructing a non-inverted arch tunnel according to claim 8, characterized in that: Also included after step S1 are the steps: S10: dividing the plurality of anchor rods (300) in the anchoring structure (3) into at least one anchor rod group (30), and making each of the anchor rod groups (30) include a plurality of anchor rods (300); S11: The anchor rod group (30) is installed at a position at least close to the bottom side edge of the protective structure (1) at the bottom ground of the tunnel space, and a plurality of anchor rods (300) in the anchor rod group (30) are distributed at intervals along the extension direction of the non-inverted arch tunnel.

10. The method for constructing a non-inverted arch tunnel according to claim 9, characterized in that: Also included after step S11: S12: After the anchor rod group (30) is installed, a colloidal material that can solidify into a solid is injected into the anchor rods (300) in a partial anchor rod group (30) or all the anchor rod groups (30) through the grouting holes on the anchor rods (300), and the colloidal material is allowed to flow into the soil around the anchor rods (300) through the grouting holes on the anchor rods (300).

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