A construction method for tunnel invert

Abstract

The invention provides a construction method for a tunnel invert, belonging to the technical field of tunnel construction. The construction method comprises the following construction steps: step 1, cleaning the surface of an initial support of the tunnel; step 2, spraying a concrete layer on the surface of the initial support; step 3, laying a waterproof layer on the concrete layer; step 4, tying the invert reinforcement, the invert reinforcement comprises an outer reinforcement layer and an inner reinforcement layer, both the outer reinforcement layer and the inner reinforcement layer comprise transverse reinforcements arranged at intervals in a direction extending perpendicular to the length of the tunnel and longitudinal reinforcements perpendicular to the transverse reinforcements, and in the tying process, the density of the transverse reinforcements and the longitudinal reinforcements is adjusted according to the position of the tunnel to adjust the supporting performance of the invert; step 5, installing an invert template and pouring concrete into the template; step 6, removing the template after the concrete solidification strength reaches a set requirement. The invention is mainly used to solve the technical problem that the existing tunnel has a risk of damage at a special position of a mountain.

Description

Technical Field

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

[0002] A tunnel is a structure built underground, underwater or in a mountain to lay a railway or build a road for motor vehicles to pass through. According to its location, it can be divided into three categories: mountain tunnels, underwater tunnels and urban tunnels. A mountain tunnel is a tunnel that passes under a mountain or hill to shorten the distance and avoid steep slopes.

[0003] The geological structure of mountain tunnels is usually complex, especially when passing through mountainous areas with large terrain undulations. It is necessary to cross multiple faults and folds. The tunnel at this location will cause disturbances to the mountain due to long-term traffic load vibrations during later operation, which makes the tunnel at risk of damage, especially the bottom invert position. The invert is one of the main components of the tunnel lining structure. It is a reverse arch structure set at the bottom of the tunnel to improve the stress conditions of the upper support structure. The invert is also the main support for traffic operation. Once damaged, it is easy to cause serious safety accidents.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a construction method for a tunnel invert, so as to solve the technical problem that the existing tunnel has the risk of damage at a special position of a mountain.

[0006] In order to achieve the above object, the construction method of the tunnel invert of the present invention provides the following technical solutions:

[0007] A construction method for a tunnel invert comprises the following construction steps:

[0008] Step 1, clean the surface of the initial support of the tunnel;

[0009] Step 2, spraying a concrete layer on the initial support surface;

[0010] Step 3, laying a waterproof layer on the concrete layer;

[0011] Step 4, tying the inverted arch reinforcement, wherein the inverted arch reinforcement comprises an outer reinforcement layer and an inner reinforcement layer, wherein the outer reinforcement layer and the inner reinforcement layer both comprise transverse reinforcements arranged at intervals perpendicular to the tunnel length extension direction and longitudinal reinforcements perpendicular to the transverse reinforcements, and during the tying process, the density of the transverse reinforcements and the longitudinal reinforcements is adjusted according to the position of the tunnel to adjust the supporting performance of the inverted arch;

[0012] Step 5, installing the invert formwork and pouring concrete into the formwork;

[0013] Step 6: Remove the formwork after the concrete solidification strength reaches the set requirements.

[0014] As a further optimized technical solution, in step 4, two symmetrically arranged positioning units are used to position the transverse reinforcements of the outer reinforcement layer and the inner reinforcement layer, and the positioning units include:

[0015] A first limiting rod, which is used to be arranged on the inner wall of the tunnel parallel to the extension direction of the tunnel length;

[0016] a second limiting rod, the second limiting rod being arranged parallel to the first limiting rod;

[0017] A distance adjustment component, which is disposed between the first limiting rod and the second limiting rod and is used to adjust the distance between the first limiting rod and the second limiting rod;

[0018] A limiting assembly, wherein the limiting assembly is slidably disposed on a side of the first limiting rod and the second limiting rod facing the transverse reinforcement, each limiting assembly is used to fix a transverse reinforcement, the first limiting rod is used to limit the outer reinforcement layer through the limiting assembly, and the second limiting rod is used to limit the inner reinforcement layer through the limiting assembly;

[0019] A fixing assembly is arranged on one side of the first limiting rod and is used to detachably fix the first limiting rod on the inner wall of the tunnel.

[0020] As a further optimized technical solution, the limit assembly includes:

[0021] A connecting block, the connecting block is used to be arranged on the first limiting rod and the second limiting rod, and a sliding channel extending along the length direction is opened inside the first limiting rod and the second limiting rod, and the connecting block is arranged in the sliding channel and can be slidably connected with the sliding channel;

[0022] The clamping structure is arranged on the connecting block and is used for automatically clamping the transverse reinforcement to define the position of the transverse reinforcement.

[0023] As a further optimized technical solution, the clamping structure includes:

[0024] A positioning column, wherein both ends of the positioning column are fixedly connected to the connecting block, and the axial direction of the positioning column is perpendicular to the length extension direction of the first limiting rod or the second limiting rod;

[0025] Automatic splints, the automatic splints have two, the two automatic splints are respectively mounted on the positioning columns and hinged with the positioning columns, the automatic splints have a driving section and a clamping section that are integrally fixedly connected, a set angle is set between the driving section and the clamping section, and the driving section of each automatic splint is set on the inner side of the clamping section of another automatic splint, after the transverse steel bars are placed between the two automatic splints, the two driving sections are pushed to rotate outward, and the two clamping sections are rotated inward to clamp the transverse steel bars.

[0026] As a further optimized technical solution, the driving section and the clamping section of the two automatic clamps extend axially along the positioning column, so that the two automatic clamps form a symmetrical structure to balance the clamping of the transverse steel bars.

[0027] As a further optimized technical solution, the limiting assembly further includes a limiting groove, which is arranged on the outside of the clamping structure and fixedly connected to the connecting block.

[0028] As a further optimized technical solution, an elastic reset member is provided in the clamping structure. The elastic reset member is arranged in the limiting groove and one end of the elastic reset member is fixedly connected to the outer wall of the clamping section, and the other end is fixedly connected to the inner wall of the limiting groove. When the transverse steel bar is not fixed, the elastic reset member pulls the clamping section to rotate outward.

[0029] As a further optimized technical solution, the fixing assembly includes:

[0030] A telescopic structure, wherein the telescopic structure comprises a connecting rod and a connecting sleeve, wherein the connecting rod is fixed on the first limiting rod, and the connecting sleeve is sleeved on the connecting rod and can be slidably matched with the connecting rod to adjust the length of the telescopic structure;

[0031] A fixing plate is fixedly connected to the telescopic structure and is used for being fixedly connected to the tunnel.

[0032] As a further optimized technical solution, the distance adjustment component includes:

[0033] A guide component, one end of which is fixedly connected to the first limiting rod, and the other end of which passes through the second limiting rod and is slidably matched with the second limiting rod;

[0034] An adjusting threaded rod, one end of which is rotationally matched with the middle part of the first limiting rod, and the other end of which passes through the second limiting rod and is threadably matched with the second limiting rod.

[0035] As a further optimized technical solution, the outer side of the guide component has an external thread, and the position where the second limit rod passes through the guide component has a through hole with a diameter larger than the diameter of the guide component. The guide component is threadedly connected with positioning nuts on both sides of the second limit rod, and the outer diameter of the positioning nuts is larger than the diameter of the through hole.

[0036] Beneficial effect: In the present invention, when tying steel bars, the density of transverse steel bars and longitudinal steel bars is appropriately adjusted according to the location of the tunnel. Specifically, in a relatively stable section of the mountain, the inverted arch steel bars can be tied according to the values ​​specified in the normal tunnel construction standards. When the tunnel is located at the fault and fold position of the mountain, the distance between the transverse steel bars in the outer steel bar layer and the inner steel bar layer can be shortened, while the distance between the outer steel bar layer and the inner steel bar layer can be increased, and the distance between the longitudinal steel bars can be shortened. In this way, in the process of tying steel bars, the volume of the overall inverted arch steel bar skeleton is increased, and the supporting strength of the inverted arch steel bar skeleton is increased, thereby increasing the overall performance and supporting performance of the tunnel at this location, and ensuring the safety performance of the tunnel at this location. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0038] Figure 1 A schematic diagram of a steel bar binding process according to an embodiment of the present invention;

[0039] Figure 2 for Figure 1 A top view of

[0040] Figure 3 for Figure 1 A magnified schematic diagram of part A;

[0041] Figure 4 It is a schematic diagram of the overall structure of a positioning unit according to an embodiment of the present invention;

[0042] Figure 5 A partial structural schematic diagram of a second limiting rod according to an embodiment of the present invention;

[0043] Figure 6 for Figure 5 A magnified schematic diagram of part B;

[0044] Figure 7 A rear view schematic diagram of a positioning unit according to an embodiment of the present invention;

[0045] Figure 8 It is a schematic diagram of the overall structure of a limit assembly according to an embodiment of the present invention;

[0046] Fig. 9 A partial structural schematic diagram of a limit assembly according to an embodiment of the present invention;

[0047] Fig.10 The figure is a schematic diagram of the working state of a limiter assembly according to an embodiment of the present invention, wherein: Fig.10(a) shows the state when the transverse reinforcement is not fixed. Fig.10 (b) shows the state after the transverse reinforcement is placed in the limiting assembly.

[0048] In the figure: 1. outer steel bar layer; 102. transverse steel bar; 2. inner steel bar layer; 3. first limit rod; 4. second limit rod; 5. distance adjustment assembly; 501. guide component; 502. adjustment threaded rod; 5021. drive block; 503. positioning nut; 6. limit assembly; 601. connecting block; 6011. positioning bolt; 602. positioning column; 603. automatic clamp; 6031. driving section; 6032. clamping section; 6033. connecting pipe; 604. limit groove; 605. elastic reset member; 606. anti-skid protrusion; 7. sliding channel; 8. fixing assembly; 801. connecting rod; 802. connecting sleeve; 803. fixing plate; 804. accommodating cavity; 805. limit member. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0050] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0051] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0052] The present invention provides a method for constructing a tunnel invert. Specifically, during the construction process, according to the mountain position where the tunnel is located, the binding method of the invert reinforcement is specifically adjusted, so that the overall strength of the tunnel is properly adjusted according to the specific conditions of the mountain, thereby ensuring the safety performance of the tunnel.

[0053] Example 1

[0054] A construction method for a tunnel invert comprises the following construction steps:

[0055] Step 1: Clean the surface of the initial tunnel support; before the invert construction, the slag and debris generated during the initial support construction process need to be cleaned up.

[0056] Step 2: spray a concrete layer on the initial support surface.

[0057] Step 3, laying a waterproof layer on the concrete layer; in the present invention, the waterproof layer specifically includes geotextile and waterproof board. Before laying the waterproof layer, the base surface formed by the concrete layer should be ensured to be solid, flat, smooth and leak-free. Then, a layer of geotextile is laid as a whole. The geotextile is fixed in a plum blossom shape using a hot-melt pad. The geotextile should be of appropriate tightness so that it can be closely attached to the surface of the shotcrete layer, and will not be torn due to being too tight, and too loose will affect the hanging of the geotextile. Then lay the waterproof board. The lap joints between the waterproof boards should be welded with three seams, and then welded with an automatic three-seam hot-melt welding machine at a predetermined temperature and speed. A handheld welding gun is used for detail processing or repair. In addition, the lap width of any two adjacent waterproof boards must be greater than 15 cm, and the lap joints between the waterproof boards should be staggered by more than 1 m from the weak waterproof links such as deformation joints and construction joints.

[0058] Step 4, tying the invert reinforcement; Figure 1 , Figure 2 As shown, the inverted arch reinforcement comprises an outer reinforcement layer 1 and an inner reinforcement layer 2. Both the outer reinforcement layer 1 and the inner reinforcement layer 2 comprise transverse reinforcements 102 arranged at intervals perpendicular to the extension direction of the tunnel length and longitudinal reinforcements (not shown in the figure) perpendicular to the transverse reinforcements 102. The inverted arch reinforcement further comprises stirrups (not shown in the figure) for connecting the outer reinforcement layer 1 and the inner reinforcement layer 2. All of the above reinforcements are used to ultimately form a reinforcement skeleton of the inverted arch.

[0059] Before tying the steel bars, the steel bars used for tying need to be straightened and derusted. The straightened wire rod steel bars are straightened by an automatic straightening and cutting machine, and the coarse steel bars are straightened by a manual straightener on the working platform. The straightened steel bars should be straight, without local bending, and without scars on the surface of the steel bars that weaken the cross section. The steel bars are derusted by sandpaper, sand tray, and wire brush to make the surface clean and free of oil stains, paint stains, and rust.

[0060] During the binding process, the density of the transverse reinforcement 102 and the longitudinal reinforcement is adjusted according to the location of the tunnel, so as to ultimately adjust the support of the invert.

[0061] Specifically, in the relatively stable mountain section, the inverted arch reinforcement can be tied according to the values ​​specified in the normal tunnel construction standards. For example, the transverse reinforcement 102 uses HRB400Φ22 steel bars, the transverse spacing between the transverse reinforcements 102 of the outer reinforcement layer 1 is 20cm, the transverse spacing between the transverse reinforcements 102 of the inner reinforcement layer 2 is 20cm, the distance between the outer reinforcement layer 1 and the inner reinforcement layer 2 is 30cm, and the longitudinal reinforcement uses HRB400Φ14 steel bars. The distance between the longitudinal reinforcements in the outer reinforcement layer 1 and the inner reinforcement layer 2 is 25cm. Among them, the longitudinal reinforcements in the outer reinforcement layer 1 and the inner reinforcement layer 2 need to be tied to the inner side of the transverse reinforcement 102. After the outer reinforcement layer 1 and the inner reinforcement layer 2 are tied, φ8 stirrups are used for tying. The two ends of the stirrups are fixedly connected to the transverse reinforcements 102 of the outer reinforcement layer 1 and the inner reinforcement layer 2 respectively.

[0062] When the tunnel is located at the fault and fold position of the mountain, the distance between the transverse steel bars 102 and the longitudinal steel bars in the outer steel layer 1 and the inner steel layer 2 can be shortened, and the distance between the outer steel layer 1 and the inner steel layer 2 can be increased. In this embodiment, for example, at the fault of the mountain, the selection of the transverse steel bars 102 and the longitudinal steel bars remains unchanged, and the distance between the transverse steel bars 102 in the outer steel layer 1 and the inner steel layer 2 is shortened to 10cm, and the distance between the longitudinal steel bars is shortened to 8cm, and the distance between the outer steel layer 1 and the inner steel layer 2 is adjusted to 40cm. In this way, in the process of tying the steel bars, the volume of the overall inverted arch steel skeleton is increased, thereby increasing the overall performance and support performance of the tunnel at this position, ensuring the safety performance of the tunnel at this position. In addition, the distance between the steel bars is appropriately adjusted at the folds of the mountain, so that the support performance of the tunnel can adapt to the terrain conditions at that location.

[0063] During the steel bar binding process, the transverse steel bars 102 need to be positioned first, and then the longitudinal steel bars are bound on the transverse steel bars 102. After the two steel bar layers are bound, the stirrups between the two steel bar layers are bound. During the binding process of the transverse steel bars 102, first, the position of the transverse steel bars 102 needs to be fixed. The existing method of fixing the transverse steel bars 102 is to weld and fix a positioning fixture on the side wall of the tunnel. The positioning fixture has relatively fixed and parallel positioning rods, and each positioning rod has positioning grooves arranged at intervals. All transverse steel bars 102 of the outer steel bar layer 1 are respectively placed in all the positioning grooves on a positioning rod.

[0064] The above-mentioned positioning tool is suitable for the construction of tunnels in stable geological conditions. For the situation in which the geological structure is relatively complex in the present invention, the distance between the two positioning rods on the tool cannot be adjusted. In addition, the distance between the positioning grooves cannot be adjusted. In order to carry out normal construction, multiple sets of positioning tooling need to be processed, which is not only inconvenient for storage and storage, but also increases the waste of production materials.

[0065] In order to adapt to the situation in which the spacing between the transverse reinforcements 102 often needs to be adjusted in the present invention, two symmetrically arranged positioning units are used in the present invention to position the transverse reinforcements 102 of the outer reinforcement layer 1 and the inner reinforcement layer 2 .

[0066] like Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown, the positioning unit includes a first limiting rod 3 , a second limiting rod 4 , a distance adjustment component 5 , a limiting component 6 , and a fixing component 8 .

[0067] The first limiting rod 3 is used to be set on the inner wall of the tunnel parallel to the extension direction of the tunnel length, the second limiting rod 4 is set parallel to the first limiting rod 3, and the distance adjustment component 5 is set between the first limiting rod 3 and the second limiting rod 4, and is used to adjust the distance between the first limiting rod 3 and the second limiting rod 4.

[0068] Specifically in this embodiment, the distance adjustment component 5 has a guide component 501 and an adjustment threaded rod 502. The two guide components 501 are respectively installed at the two ends of the first limiting rod 3 and the second limiting rod 4. One end of the guide component 501 is vertically fixedly connected to the first limiting rod 3, and the other end vertically passes through the second limiting rod 4 and slides with the second limiting rod 4. The second limiting rod 4 slides axially along the guide component 501 to adjust the distance between the first limiting rod 3 and the second limiting rod 4.

[0069] The adjusting threaded rod 502 is installed in the middle of the first limiting rod 3 and the second limiting rod 4, and is perpendicular to the length extension direction of the first limiting rod 3 and the second limiting rod 4. One end of the adjusting threaded rod 502 is rotationally matched with the middle of the first limiting rod 3, and the other end passes through the second limiting rod 4 and is threadedly matched with the second limiting rod 4. In this way, by rotating the adjusting threaded rod 502, the second limiting rod 4 can be driven to slide axially along the guide component 501, so as to adjust the distance between the first limiting rod 3 and the second limiting rod 4.

[0070] In order to facilitate the stable maintenance of the distance between the first limiting rod 3 and the second limiting rod 4 after the adjustment is completed, the outer side of the guide component 501 has an external thread, and the second limiting rod 4 has a through hole with a diameter larger than the diameter of the guide component 501 at the position where the guide component 501 passes through, and the guide component 501 is threadedly connected with positioning nuts 503 at the positions on both sides of the second limiting rod 4, and the outer diameter of the positioning nuts 503 is larger than the diameter of the through hole. That is, the positioning nuts 503 are used to further limit the distance of the second limiting rod 4, so that the distance between the first limiting rod 3 and the second limiting rod 4 is stably maintained.

[0071] Specifically, during use, when it is necessary to adjust the distance between the first limit rod 3 and the second limit rod 4, the positioning nuts 503 are screwed so that a sufficient distance is maintained between the positioning nuts 503 on both sides of the second limit rod 4 and the second limit rod 4 to facilitate the second limit rod 4 to slide along the guide component 501. Then, the second limit rod 4 is driven to move to a distance that meets the requirements with the first limit rod 3 by screwing the adjustment threaded rod 502, and then the positioning nuts 503 on both sides of the guide component 501 are screwed to tighten the second limit rod 4.

[0072] In the process of adjusting the distance between the first limiting rod 3 and the second limiting rod 4, in order to facilitate the screwing and adjusting of the threaded rod 502, a driving block 5021 with a regular polygonal cross section is provided at one end of the threaded rod 502. The driving block 5021 has a stable contact surface, so that it is convenient to be clamped by a tool to screw the threaded rod 502.

[0073] like Figure 5 , Figure 6 , Figure 7 As shown, the limiting assembly 6 can be slidably arranged on the side of the first limiting rod 3 and the second limiting rod 4 facing the transverse steel bar 102, and each limiting assembly 6 is used to fix a transverse steel bar 102; the first limiting rod 3 limits the outer steel bar layer 1 through the limiting assembly 6, and the second limiting rod 4 limits the inner steel bar layer 2 through the limiting assembly 6.

[0074] In this embodiment, the limiting assembly 6 includes a connecting block 601 and a clamping structure.

[0075] like Figure 8As shown, the cross section of the connecting block 601 is a "convex" shape, with two parts with different cross sections connected in one piece, and the corresponding first limiting rod 3 and the second limiting rod 4 are both provided with a sliding channel 7 extending along the length direction, and the connecting block 601 is arranged in the sliding channel 7 of the first limiting rod 3 and the second limiting rod 4 and can be slidably connected with the sliding channel 7, wherein the part with a larger cross section of the connecting block 601 is arranged inside the sliding channel 7, and the part with a smaller cross section is used to extend the sliding channel 7, so that the sliding channel 7 is convenient for limiting the front and rear directions of the connecting block 601, so that the connecting block 601 can only move along the length direction of the first limiting rod 3 and the second limiting rod 4 to adjust the distance between adjacent connecting blocks 601. Specifically, after adjusting the distance to meet the requirements, the connecting block 601 needs to be fixed to avoid sliding during the construction process, and the transverse steel bar 102 cannot be stably limited. In order to facilitate the fixing of the connecting block 601, the sliding channel 7 directly passes through the front and rear sides of the first limiting rod 3 and the second limiting rod 4, and a positioning bolt 6011 is threadedly connected to the rear side of the connecting block 601. Specifically, the screw portion of the positioning bolt 6011 passes through the rear side of the sliding channel 7 and extends into the connection block 601. The connection block 601 has a threaded hole threadedly connected to the positioning bolt 6011. When the distance between the connection blocks 601 needs to be adjusted, the positioning bolt 6011 is screwed outward to facilitate the movement of the connection block 601 along the sliding channel 7. When the movement is completed, the positioning bolt 6011 is screwed inward to make the positioning bolt 6011 press against the side wall of the first limiting rod 3 or the second limiting rod 4, thereby achieving the position fixation of the positioning bolt 6011.

[0076] like Fig. 9 As shown, the clamping structure is disposed on the front side of the connecting block 601 , and is used to automatically clamp the transverse reinforcement 102 to define the position of the transverse reinforcement 102 .

[0077] Specifically, the clamping structure includes a positioning column 602 and an automatic clamping plate 603 .

[0078] Both ends of the positioning column 602 are fixedly connected to the connecting block 601 , and the axial direction of the positioning column 602 is perpendicular to the length extension direction of the first limiting rod 3 or the second limiting rod 4 .

[0079] The automatic splint 603 has two, the two automatic splints 603 are respectively sleeved on the positioning column 602 and hinged with the positioning column 602, the automatic splint 603 has a driving section 6031 and a clamping section 6032 which are integrally fixedly connected through a connecting pipe 6033, the connecting pipe 6033 is used to be sleeved on the positioning column 602, the driving section 6031 and the clamping section 6032 are respectively arranged on both sides of the connecting pipe 6033, and form a set angle, that is, a set angle is set between the driving section 6031 and the clamping section 6032, and the driving section 6031 of each automatic splint 603 is arranged at the clamping section 6032 of another automatic splint 603 032, on the inner side, along the axial projection direction of the positioning column 602, the driving sections 6031 of the two automatic splints 603 form an angle structure, and are sleeved inside the angle structure formed by the clamping sections 6032 of the two automatic splints 603. In this embodiment, the length of the two driving sections 6031 is smaller than the radius of the transverse steel bars 102. When tying the transverse steel bars 102, both ends of the transverse steel bars 102 are bent upward and clamped between the automatic splints 603 of the two positioning units. Under the deformation pressure of the transverse steel bars 102, the two driving sections 6031 are pushed to rotate outward. At this time, the two clamping sections 6032 rotate inward to clamp the transverse steel bars 102.

[0080] On the basis of the above technical scheme, because the two automatic splints 603 are arranged axially along the positioning column 602, when clamping the transverse steel bar 102, the clamping sections 6032 of the two automatic splints 603 are staggered up and down in the axial direction, so it is not easy to maintain balance when clamping the transverse steel bar 102. In order to balance the clamping of the transverse steel bar 102, the driving section 6031 and the clamping section 6032 of the upper automatic splint 603 extend downward and extend to align with the bottom of the automatic splint 603 below, and the driving section 6031 and the clamping section 6032 of the lower automatic splint 603 extend upward and extend to align with the top of the automatic splint 603 above, that is, the driving section 6031 and the clamping section 6032 of the two automatic splints 603 both extend axially along the positioning column 602, so that the two automatic splints 603 form a symmetrical structure, so that the transverse steel bar 102 can be clamped symmetrically.

[0081] Furthermore, the limiting assembly 6 also includes a limiting groove 604, which is arranged on the outside of the clamping structure and fixedly connected to the connecting block 601. By setting the limiting groove 604, the automatic splint 603 can be protected to avoid bumping into the automatic splint 603 during use.

[0082] Furthermore, an elastic reset member 605 is provided in the clamping structure. The elastic reset member 605 is arranged in the limiting groove 604 and one end of the elastic reset member 605 is fixedly connected to the outer wall of the clamping section 6032, and the other end is fixedly connected to the inner wall of the limiting groove 604. When the transverse steel bar 102 is not fixed, the elastic reset member 605 pulls the clamping section 6032 to rotate outward.

[0083] Fig.10 The working state of the limit component 6 is shown. Fig.10 (a) shows the state when the transverse reinforcement 102 is not fixed. At this time, the elastic reset member 605 pulls the two clamping sections 6032 to open outward, thereby facilitating the placement of the transverse reinforcement 102. Fig.10 (b) shows the state after the transverse reinforcement 102 is placed in the limiting assembly 6. At this time, the transverse reinforcement 102 pushes the two driving sections 6031 to rotate outward under the action of its own tension, and the two clamping sections 6032 rotate inward to clamp the transverse reinforcement 102.

[0084] In this embodiment, in order to ensure the degree of clamping of the clamping section 6032 on the transverse steel bar 102 , an anti-slip protrusion 606 is provided on the inner side of the clamping section 6032 .

[0085] like Figure 1 , Figure 2 , Figure 3 As shown, the fixing assembly 8 is arranged on one side of the first limiting rod 3, and is used to detachably fix the first limiting rod 3 on the inner wall of the tunnel.

[0086] In this embodiment, the fixing assembly 8 includes a telescopic structure and a fixing plate 803 .

[0087] The telescopic structure comprises a connecting rod 801 and a connecting sleeve 802. The middle of the connecting sleeve 802 comprises a receiving cavity 804 whose size matches that of the connecting rod 801. Figure 3 As shown, the accommodating cavity 804 is used to be sleeved on the connecting rod 801, and the connecting rod 801 is fixed on the first limiting rod 3. The accommodating cavity 804 of the connecting sleeve 802 is sleeved on the connecting rod 801 and can be slidably matched with the connecting rod 801 to adjust the length of the telescopic structure. Specifically, a set screw is spirally connected to the bottom of the connecting sleeve 802 as a limiting member 805. The limiting member 805 can press or loosen the connecting rod 801. The telescopic distance between the connecting rod 801 and the connecting sleeve 802 is adjusted through the limiting member 805. In this way, after the steel bar is tied, the transverse steel bar 102 has been shaped and positioned. According to the automatic clamping principle of the clamping structure, when disassembling the positioning unit, the telescopic structure can be used to withdraw a distance as a whole. During the withdrawal process, the transverse steel bar 102 no longer presses the driving section 6031. At this time, the clamping section 6032 is automatically opened, so as to facilitate the disassembly of the positioning unit.

[0088] The fixing plate 803 is fixedly connected to the telescopic structure. Specifically, the fixing plate 803 is provided with fixing holes for detachably fixing the plate with the tunnel.

[0089] Step 5, installing the invert formwork and pouring concrete into the formwork;

[0090] Step 6: Remove the formwork after the concrete solidification strength reaches the set requirements.

[0091] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0092] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A method for constructing a tunnel invert, characterized in that: The construction steps include: Step 1, clean the surface of the initial support of the tunnel; Step 2, spraying a concrete layer on the initial support surface; Step 3, laying a waterproof layer on the concrete layer; Step 4, tying the inverted arch reinforcement, the inverted arch reinforcement comprises an outer reinforcement layer (1) and an inner reinforcement layer (2), the outer reinforcement layer (1) and the inner reinforcement layer (2) both comprising transverse reinforcements (102) arranged at intervals perpendicular to the tunnel length extension direction and longitudinal reinforcements perpendicular to the transverse reinforcements (102), and during the tying process, the density of the transverse reinforcements (102) and the longitudinal reinforcements is adjusted according to the location of the tunnel to adjust the supporting performance of the inverted arch; Step 5, installing the invert formwork and pouring concrete into the formwork; Step 6, after the concrete solidification strength reaches the set requirements, the formwork is removed; In step 4, two symmetrically arranged positioning units are used to position the transverse steel bars (102) of the outer steel bar layer (1) and the inner steel bar layer (2), wherein the positioning units include: A first limiting rod (3), the first limiting rod (3) being used to be arranged on the inner wall of the tunnel in parallel with the extension direction of the tunnel length; A second limiting rod (4), the second limiting rod (4) being arranged parallel to the first limiting rod (3); A distance adjustment component (5), the distance adjustment component (5) being arranged between the first limiting rod (3) and the second limiting rod (4) and being used for adjusting the distance between the first limiting rod (3) and the second limiting rod (4); A limiting assembly (6), the limiting assembly (6) being slidably arranged on a side of the first limiting rod (3) and the second limiting rod (4) facing the transverse reinforcement (102), each limiting assembly (6) being used to fix a transverse reinforcement (102), the first limiting rod (3) limiting the outer reinforcement layer (1) through the limiting assembly (6), and the second limiting rod (4) limiting the inner reinforcement layer (2) through the limiting assembly (6); A fixing assembly (8), the fixing assembly (8) being arranged on one side of the first limiting rod (3) and being used for detachably fixing the first limiting rod (3) on the inner wall of the tunnel; The limiting component (6) comprises: A connecting block (601), the connecting block (601) being used to be arranged on the first limiting rod (3) and the second limiting rod (4), and the first limiting rod (3) and the second limiting rod (4) are each provided with a sliding channel (7) extending along the length direction, and the connecting block (601) is arranged in the sliding channel (7) and can be slidably connected to the sliding channel (7); a clamping structure, the clamping structure being arranged on the connection block (601) and being used for automatically clamping the transverse reinforcement (102) to define the position of the transverse reinforcement (102); The clamping structure comprises: A positioning column (602), wherein both ends of the positioning column (602) are fixedly connected to the connecting block (601), and the axial direction of the positioning column (602) is perpendicular to the length extension direction of the first limiting rod (3) or the second limiting rod (4); The automatic splint (603) comprises two automatic splints (603), the two automatic splints (603) are respectively sleeved on the positioning column (602) and hinged to the positioning column (602), the automatic splint (603) comprises a driving section (6031) and a clamping section (6032) which are integrally fixedly connected, a set angle is arranged between the driving section (6031) and the clamping section (6032), and the driving section (6031) of each automatic splint (603) is arranged on the inner side of the clamping section (6032) of another automatic splint (603), and after the transverse steel bar (102) is placed between the two automatic splints (603), the two driving sections (6031) are pushed to rotate outward, and the two clamping sections (6032) are rotated inward to clamp the transverse steel bar (102).

2. The method for constructing a tunnel invert according to claim 1, characterized in that: The driving sections (6031) and the clamping sections (6032) of the two automatic clamping plates (603) both extend axially along the positioning column (602), so that the two automatic clamping plates (603) form a symmetrical structure to clamp the transverse steel bars (102) in a balanced manner.

3. The construction method of a tunnel invert according to claim 1, characterized in that: The limiting assembly (6) further comprises a limiting groove (604), wherein the limiting groove (604) is arranged outside the clamping structure and is fixedly connected to the connecting block (601).

4. The method for constructing a tunnel invert according to claim 3, characterized in that: An elastic reset member (605) is provided in the clamping structure. The elastic reset member (605) is arranged in the limiting groove (604) and one end of the elastic reset member is fixedly connected to the outer wall of the clamping section (6032), and the other end is fixedly connected to the inner wall of the limiting groove (604). When the transverse steel bar (102) is not fixed, the elastic reset member (605) pulls the clamping section (6032) to rotate outward.

5. The method for constructing a tunnel invert according to any one of claims 1 to 4, characterized in that: The fixing assembly (8) comprises: A telescopic structure, the telescopic structure comprising a connecting rod (801) and a connecting sleeve (802), the connecting rod (801) being fixed on a first limiting rod (3), the connecting sleeve (802) being sleeved on the connecting rod (801) and being slidably matched with the connecting rod (801) to adjust the length of the telescopic structure; A fixing plate (803), wherein the fixing plate (803) is fixedly connected to the telescopic structure and is used for being fixedly connected to the tunnel.

6. The method for constructing a tunnel invert according to any one of claims 1 to 4, characterized in that: The distance adjustment component (5) comprises: A guide component (501), wherein one end of the guide component (501) is fixedly connected to the first limiting rod (3), and the other end of the guide component passes through the second limiting rod (4) and is slidably engaged with the second limiting rod (4); An adjusting threaded rod (502) has one end that is rotationally engaged with the middle portion of the first limiting rod (3), and the other end that passes through the second limiting rod (4) and is threadably engaged with the second limiting rod (4).

7. The method for constructing a tunnel invert according to claim 6, characterized in that: The outer side of the guide component (501) has an external thread, and the position of the second limiting rod (4) corresponding to the guide component (501) passing through has a through hole with a diameter greater than the diameter of the guide component (501), and the guide component (501) is threadedly connected with positioning nuts (503) at positions on both sides of the second limiting rod (4), and the outer diameter of the positioning nuts (503) is greater than the diameter of the through hole.

Images