Lock foot supporting structure of tunnel profile steel arch center
By combining the stiffening structure on the steel arch frame with the serpentine and straight sections, the connection strength is enhanced and grouting is carried out, which solves the problem of weak stress stiffness of the steel arch frame, realizes the uniform transmission of surrounding rock pressure and improves the stability of the tunnel.
Patent Information
- Application Number
- CN202520863305.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-04-30
AI Technical Summary
The existing steel arch frame has weak stress stiffness, and the joint between the anchor bolt and the steel arch frame is prone to cracking. The surrounding rock pressure is difficult to be transmitted evenly, resulting in stress concentration and affecting the safety and stability of tunnel excavation support.
The stiffening structure is connected in parallel to the web of the steel arch frame. The serpentine section is inserted into the bedrock and the straight section is connected to the stiffening structure. The connection strength is enhanced by reinforcing steel bars, and the hollow channel of the anchor bolt is used for grouting to enhance the anchoring effect.
It improves the stress stiffness of the steel arch frame, evenly transmits the pressure of the surrounding rock, avoids stress concentration, enhances the safety and stability of tunnel excavation and support, and reduces safety hazards during construction and operational risks in the later stage.
Smart Images
Figure CN223952652U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of tunnel engineering, and particularly relates to a tunnel steel arch support structure. BACKGROUND
[0002] In the field of tunnel excavation and support engineering, due to the characteristics of broken structure, poor integrity, and low rock strength of the surrounding rock of Class IV and Class V, the stability is poor, and under the disturbance of tunnel excavation operation, adverse phenomena such as deformation and collapse are prone to occur, which seriously threatens the construction safety and engineering quality. In order to ensure the stability of the surrounding rock during tunnel construction, a steel arch is often used as a primary support means. When the steel arch bears the pressure of the surrounding rock above the tunnel after excavation, the pressure will be transmitted along the arch structure and concentrated at the arch foot. As the key support point of the steel arch, the arch foot is prone to sinking and deformation when bearing excessive pressure. The deformation of the arch not only reduces the supporting effect, but also may cause the deformation of the surrounding rock to further intensify, forming a vicious cycle, and even causing a tunnel collapse accident in severe cases. Therefore, in order to effectively improve the overall stiffness and stability of the steel arch, prevent the sinking and deformation of the arch foot, and set a lock foot anchor rod at the arch foot position has become a common engineering measure.
[0003] However, the lock foot anchor rod in the current engineering practice is mostly fixed by bending the end and welding it outside the steel arch. This method has a series of problems that cannot be ignored. On the one hand, the effective length and thickness of the weld at the overlap between the lock foot anchor rod and the steel arch are limited, and when bearing a large surrounding rock pressure and tension, the lock foot anchor rod is prone to cracking at the weld, thereby weakening the anchoring effect of the anchor rod on the arch. On the other hand, the steel arch mainly bears axial force when under stress, and its structural characteristics make it difficult for the surrounding rock pressure to be evenly transmitted to the lock foot anchor rod, resulting in the lock foot anchor rod failing to fully exert its anchoring efficiency, causing stress concentration in some areas and insufficient anchoring in some areas. The above problems directly affect the stress stiffness of the steel arch, making the steel arch unable to reliably transmit the surrounding rock load to the deep stable rock mass, thereby seriously threatening the safety of tunnel excavation and support, and increasing the safety hazards in the construction process and the risk in the later operation. CONTENT OF THE UTILITY MODEL
[0004] The main purpose of the present application is to provide a tunnel steel arch support structure, which aims to solve the technical problem of weak stress stiffness of the existing steel arch.
[0005] To achieve the above-mentioned purpose, the present application provides a tunnel steel arch support structure for connecting with the arch foot position of the steel arch, which comprises:
[0006] A stiffening structure connected with the arch foot position of the steel arch, and the stiffening structure is arranged in parallel with the web of the steel arch;
[0007] A lock foot anchor rod having a serpentine section and a straight section, the serpentine section is used for inserting into the bedrock, and the straight section is used for connecting with the stiffening structure; and,
[0008] A reinforcing steel connected with the stiffening structure, and the reinforcing steel is connected with the lock foot anchor rod.
[0009] Optionally, the reinforcing steel includes four L-shaped steels, and the four L-shaped steels are symmetrically connected with the stiffening structure and form a connecting gap part matched with the lock foot anchor rod.
[0010] Optionally, the stiffening structure includes a first stiffening plate, a second stiffening plate and a positioning piece, the first stiffening plate is connected with the steel arch, the second stiffening plate is rotationally connected with the first stiffening plate, the reinforcing steel is connected with the second stiffening plate, a plurality of first positioning holes are symmetrically formed on the first stiffening plate, a plurality of second positioning holes are formed on the second stiffening plate in a circumferential direction, and the positioning piece connects the second stiffening plate with the first stiffening plate by penetrating through the second positioning holes and the first positioning holes.
[0011] Optionally, the stiffening structure further includes a rotating part, the rotating part includes a pin shaft and a shaft sleeve, one end of the pin shaft is fixedly connected with the second stiffening plate, the other end of the pin shaft is rotationally connected with the first stiffening plate, and the shaft sleeve is arranged between the pin shaft and the first stiffening plate.
[0012] Optionally, a plurality of tenons are arranged on the serpentine section.
[0013] Optionally, the tenons are arranged at the peak positions of each bending part of the serpentine section.
[0014] Optionally, an external thread is arranged on one side of the straight section close to the serpentine section.
[0015] Optionally, the lock foot anchor rod has a hollow channel inside, one end of the lock foot anchor rod is provided with a grout feeding hole connected with the hollow channel, and the surface of the lock foot anchor rod is provided with a grout outlet hole connected with the hollow channel.
[0016] Optionally, the number of the grout outlet holes is a plurality, and the plurality of grout outlet holes are uniformly arranged along the axial direction of the lock foot anchor rod.
[0017] The application can achieve the following beneficial effects:
[0018] The tunnel type steel arch lock foot support structure provided by the embodiment of the present application is connected in parallel with the stiffening structure and the web plate of the steel arch, the connecting area is increased, and the bearing capacity of the arch foot part is improved; the serpentine section is inserted into the bedrock to increase the contact area and friction of the anchor rod and the bedrock, increase the bonding force and the tensile strength, the linear section is connected with the stiffening structure to ensure the smoothness of load transmission; the reinforcing steel connects the stiffening structure and the lock foot anchor rod, the length and thickness of the weld at the connecting part are increased, the connecting strength is improved, the surrounding rock pressure can be more evenly transmitted to the lock foot anchor rod, stress concentration is effectively avoided, the stress rigidity of the steel arch is enhanced, and the safety and stability of the tunnel excavation support are improved, and the safety hidden danger in the construction process and the post-operation risk are reduced. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 FIG. 1 is a schematic diagram of the installation of a tunnel type steel arch lock foot support structure according to an embodiment of the present application;
[0020] Figure 2 FIG. 2 is a schematic diagram of the cross-sectional structure of a tunnel type steel arch lock foot support structure according to an embodiment of the present application;
[0021] Figure 3 FIG. 3 is a schematic diagram of the structure of the first stiffening plate and the second stiffening plate of a tunnel type steel arch lock foot support structure according to an embodiment of the present application;
[0022] Figure 4 FIG. 4 is a schematic diagram of the cross-sectional structure of the first stiffening plate and the second stiffening plate of a tunnel type steel arch lock foot support structure according to an embodiment of the present application.
[0023] In the drawings, the reference signs are as follows:
[0024] 1-steel arch; 2-stiffening structure; 3-lock foot anchor rod; 4-serpentine section; 5-linear section; 6-reinforcing steel; 7-first stiffening plate; 8-second stiffening plate; 9-positioning part; 10-second positioning hole; 11-rotating part; 12-pivot; 13-axle sleeve; 14-tongue; 15-external thread; 16-grouting hole.
[0025] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.
[0027] Referring to Figure 1 and Figure 2 A tunnel steel arch lock foot support structure for connecting with the arch foot position of a steel arch 1, the lock foot support structure comprising:
[0028] A stiffening structure 2 connected with the arch foot position of the steel arch 1, and the stiffening structure 2 is arranged in parallel with the web of the steel arch 1;
[0029] A lock foot anchor rod 3 having a serpentine section 4 for insertion into bedrock and a straight section 5 for connection with the stiffening structure 2; and,
[0030] A reinforcing steel bar 6 connected to the stiffening structure 2 and connected with the lock foot anchor rod 3.
[0031] Specifically, in the construction of the tunnel steel arch lock foot support structure, first, the stiffening structure 2 is connected with the arch foot position of the steel arch 1, ensuring that the stiffening structure 2 is parallel to the web of the steel arch 1, and reliable connection methods such as welding can be used to ensure stable connection. Then, the lock foot anchor rod 3 is driven into the bedrock at a predetermined angle and position, and its straight section 5 is connected with the already installed stiffening structure 2 and reinforcing steel bar 6. The connection method can be a reliable connection method such as welding or mechanical connection to ensure that the entire lock foot support structure forms a stable whole, effectively bearing and transferring loads and enhancing the stability of the steel arch 1.
[0032] The tunnel steel arch lock foot support structure described in the above embodiment connects the stiffening structure 2 with the web of the steel arch 1 in parallel, increasing the connection area and improving the load-bearing capacity of the arch foot position; the serpentine section 4 inserted into the bedrock increases the contact area and friction between the anchor rod and the bedrock, increasing the bonding force and pullout resistance, and the straight section 5 is connected with the stiffening structure 2, ensuring the smoothness of load transfer; the reinforcing steel bar 6 connects the stiffening structure 2 and the lock foot anchor rod 3, increasing the length and thickness of the weld at the connection position and improving the connection strength, so that the surrounding rock pressure can be more evenly transferred to the lock foot anchor rod 3, effectively avoiding stress concentration, enhancing the stress rigidity of the steel arch 1, and thus improving the safety and stability of the tunnel excavation support, reducing the safety hazards in the construction process and the risk of later operation.
[0033] As a kind of implementable way, referring to Figure 1 and Figure 3 The reinforcing steel bar 6 includes four L-shaped steel bars, which are symmetrically connected to the stiffening structure 2 and form a connection gap part matched with the lock foot anchor rod 3.
[0034] Specifically, the four L-shaped steel bars symmetrically connected to the stiffening structure 2 form a connecting gap part matched with the lock foot anchor 3. When the surrounding rock pressure acts on the steel arch 1 and is transmitted to the lock foot support structure, the L-shaped steel bars use their special shape to make the connection of the lock foot anchor 3 in the gap part more stable. Due to the symmetrical arrangement, the lock foot anchor 3 can be constrained from multiple directions, ensuring that the anchor can be effectively supported when subjected to tension and pressure, and the load is evenly distributed. At the same time, the four L-shaped steel bars greatly increase the length and thickness of the weld at the connecting part, significantly improving the connection strength between the lock foot anchor 3 and the stiffening structure 2, and effectively avoiding stress concentration. Further, the stability of the entire lock foot support structure is enhanced, and the steel arch 1 can more reliably transmit the surrounding rock load to the deep stable rock mass.
[0035] As an implementable manner, referring to Figure 3 , the stiffening structure 2 includes a first stiffening plate 7, a second stiffening plate 8, and a positioning member 9. The first stiffening plate 7 is connected to the steel arch 1, the second stiffening plate 8 is rotationally connected to the first stiffening plate 7, the reinforcing steel bars 6 are connected to the second stiffening plate 8, a plurality of first positioning holes are symmetrically formed in the first stiffening plate 7, a plurality of second positioning holes 10 are formed in the second stiffening plate 8, and the positioning member 9 connects the second stiffening plate 8 and the first stiffening plate 7 by passing through the second positioning holes 10 and the first positioning holes.
[0036] Specifically, when encountering lock foot anchors 3 of different angles due to errors, the second stiffening plate 8 is rotationally connected to the first stiffening plate 7, and the angle can be adjusted by rotating the second stiffening plate 8, so that the reinforcing steel bars 6 thereon can be adapted to the lock foot anchors 3. After adjusting the angle, the positioning member 9 is passed through the second positioning holes 10 on the second stiffening plate 8 and the corresponding first positioning holes on the first stiffening plate 7, thereby fixedly connecting the second stiffening plate 8 and the first stiffening plate 7. Without the need for on-site welding of reinforcing steel bars 6 of different angles to adapt to the angle of the lock foot anchor 3, both the time cost and the quality instability problem caused by on-site welding operation are avoided, and the construction efficiency is improved. At the same time, this adjustable angle design can flexibly cope with construction errors, ensure the effective connection of the lock foot support structure and the lock foot anchor 3, and enhance the stability and reliability of the entire tunnel steel arch 1 lock foot support structure.
[0037] As an implementable manner, referring to Figure 4 , the stiffening structure 2 further includes a rotating member 11, the rotating member 11 includes a pin shaft 12 and a shaft sleeve 13, one end of the pin shaft 12 is fixedly connected to the second stiffening plate 8, the other end of the pin shaft 12 is rotationally connected to the first stiffening plate 7, and the shaft sleeve 13 is arranged between the pin shaft 12 and the first stiffening plate 7.
[0038] Specifically, when the lock foot anchor rod 3 has different angles due to construction errors, because one end of the pin shaft 12 is fixed with the second stiffening plate 8 and the other end is rotatably connected with the first stiffening plate 7, the second stiffening plate 8 can rotate around the pin shaft 12, and the shaft sleeve 13 is arranged between the pin shaft 12 and the first stiffening plate 7, which reduces the rotating friction, so that the second stiffening plate 8 can smoothly adjust the angle, and the reinforcing steel bars 6 connected with the second stiffening plate 8 can be adapted to the lock foot anchor rod 3.
[0039] As an implementable manner, referring to Figure 1 and Figure 2 , the snake-shaped segment 4 is provided with a plurality of tenons 14.
[0040] Specifically, in the lock foot support structure of the tunnel steel arch 1, when the snake-shaped segment 4 is inserted into the bedrock, the tenon 14 is embedded into the bedrock, which increases the mechanical bite force between the snake-shaped segment 4 and the bedrock. The bedrock blocks the tenon 14, so that the anchoring effect of the snake-shaped segment 4 in the bedrock is enhanced. When the steel arch 1 bears the surrounding rock pressure and transmits it to the bedrock through the lock foot anchor rod 3, the tenon 14 can more effectively resist the pullout and displacement of the anchor rod.
[0041] As an implementable manner, referring to Figure 1 and Figure 2 , the tenon 14 is arranged at the peak position of each bending part of the snake-shaped segment 4.
[0042] Specifically, when the snake-shaped segment 4 of the lock foot anchor rod 3 is inserted into the bedrock, the tenon 14 at the peak position of each bending part can be in close contact with the bedrock to the maximum extent. Under the action of the surrounding rock pressure, the tenon 14 is embedded into the bedrock, and the special structure at the peak position is used to better resist the displacement and pullout of the anchor rod. Because the peak position is protruding, the reaction force of the bedrock on the tenon 14 can be more effectively converted into stable support force on the anchor rod, so that the anchoring of the snake-shaped segment 4 and the bedrock is more firm.
[0043] As an implementable manner, referring to Figure 1 and Figure 2 , the straight segment 5 is provided with external threads 15 on one side close to the snake-shaped segment 4.
[0044] Specifically, the external threads 15 can be used for temporary positioning, so that the lock foot anchor rod 3 can be kept stable during installation, displacement can be avoided when being inserted into the bedrock or connected with the stiffening structure 2, the accuracy and stability of the installation of the entire lock foot support structure are ensured, and the construction cost and safety risk are reduced.
[0045] As an implementable manner, referring to Figure 1 and Figure 2The locking foot anchor rod 3 has a hollow channel inside, and one end of the locking foot anchor rod 3 is provided with a grout conveying hole connected to the hollow channel. The surface of the locking foot anchor rod 3 is provided with a grout outlet hole 16 connected to the hollow channel.
[0046] Specifically, during grouting, grout is injected into the hollow channel of the anchor bolt 3 through the grout delivery hole. Since the hollow channel is connected to the grout outlet 16, the grout flows along the hollow channel and is evenly squeezed out from the outlet 16 into the bedrock fissures around the anchor bolt. As the grout is continuously injected, the pressure gradually increases, causing the grout to diffuse in the bedrock and fill the gap between the anchor bolt and the bedrock. This results in a more even distribution of the grout around the anchor bolt, greatly enhancing the bond between the anchor bolt and the bedrock and significantly improving the anchoring effect. Simultaneously, the diffusion and filling of the grout effectively reinforces the bedrock, improving its stability and thus enhancing the load-bearing capacity of the entire anchor bolt support structure. This ensures the stability of the tunnel steel arch frame 1 under the pressure of the surrounding rock, reduces the risk of tunnel collapse, and improves the safety of tunnel construction and subsequent use.
[0047] As an feasible approach, refer to Figure 1 and Figure 2 The number of grout outlet holes 16 is several, and the several grout outlet holes 16 are evenly arranged along the axial direction of the anchor bolt 3.
[0048] Specifically, when grout is injected into the hollow channel of the anchor bolt 3, due to the large number of grout outlet holes 16 and their uniform axial arrangement, the grout can flow out relatively evenly from each outlet hole 16 under pressure. During the insertion of the anchor bolt into the bedrock, the evenly flowing grout can fill the gaps between the anchor bolt and the bedrock at different locations, ensuring that all parts of the anchor bolt and the bedrock can fully contact the grout and form a uniform bonding layer.
[0049] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A tunnel type steel arch lock foot support structure for connection with a steel arch at a position of a foot of the steel arch, characterized in that, The locking foot support structure comprises: a stiffening structure connected with the arch foot position of the steel arch, and the stiffening structure is arranged in parallel with the web of the steel arch; a locking foot anchor rod having a serpentine section and a straight section, the serpentine section being used for insertion into bedrock, and the straight section being used for connection with the stiffening structure; and a reinforcing steel bar connected with the stiffening structure and connected with the locking foot anchor rod.
2. The tunnel-type steel arch lock foot support structure according to claim 1, wherein The reinforcing steel bar comprises four L-shaped steel bars symmetrically connected with the stiffening structure and forming a connecting gap part matched with the locking foot anchor rod.
3. The tunnel-type steel arch lock foot support structure according to claim 2, wherein The stiffening structure comprises a first stiffening plate connected with the steel arch, a second stiffening plate rotationally connected with the first stiffening plate, and a positioning member, the reinforcing steel bar being connected with the second stiffening plate, a plurality of first positioning holes being symmetrically formed in the first stiffening plate, a plurality of second positioning holes being formed in the second stiffening plate in a circumferential direction, and the positioning member connecting the second stiffening plate with the first stiffening plate by penetrating the second positioning holes and the first positioning holes.
4. The tunnel-type steel arch lock foot support structure according to claim 3, wherein The stiffening structure further comprises a rotating member, the rotating member comprising a pin shaft and a shaft sleeve, one end of the pin shaft being fixedly connected with the second stiffening plate, the other end of the pin shaft being rotationally connected with the first stiffening plate, and the shaft sleeve being arranged between the pin shaft and the first stiffening plate.
5. The tunnel-type steel arch lock foot support structure according to claim 1, wherein A plurality of tenons are arranged on the serpentine section.
6. The tunnel-type steel arch lock foot support structure according to claim 5, wherein The tenons are arranged at the peak positions of each curved part of the serpentine section.
7. The tunnel-type steel arch lockset support structure according to claim 1, wherein, An external thread is arranged on one side of the straight section close to the serpentine section.
8. The tunnel type steel arch lock foot support structure according to claim 1, wherein, The locking foot anchor rod has a hollow channel inside, and one end of the locking foot anchor rod is provided with a grout feeding hole in communication with the hollow channel, and the surface of the locking foot anchor rod is provided with a grout outlet hole in communication with the hollow channel.
9. The tunnel-type steel arch lockset support structure according to claim 8, wherein, The number of the grout outlet holes is a plurality, and the plurality of grout outlet holes are uniformly arranged along the axial direction of the locking foot anchor rod.