Tunnel primary support expansion foot unit component
By designing the tunnel initial support enlargement foot unit components, the arch foot support area was increased and the initial support stiffness was improved, which solved the problems of tunnel initial support arch foot subsidence and surrounding rock relaxation, and improved construction efficiency and quality.
Patent Information
- Application Number
- CN202520636400.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-04-07
AI Technical Summary
In the construction of tunnels in weak surrounding rock, problems such as subsidence, severe convergence, excessive deformation and collapse of the initial support arch are difficult to control effectively. Existing technical methods have limited applicability and are inefficient and costly.
A tunnel initial support enlargement foot unit component is designed, consisting of arch frame uprights, arch frame diagonal braces, arch frame bottom foot rods, connecting steel plates, and bottom foot steel plates, forming a triangular structure. This increases the support area of the tunnel initial support arch foot and improves the initial support stiffness. Through factory prefabrication and connection, it simplifies the construction inside the tunnel.
It effectively controls tunnel arch subsidence and surrounding rock relaxation, improves construction efficiency, reduces tunnel construction time, ensures project quality and safety, and achieves economical and efficient support effects.
Smart Images
Figure CN223825008U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of tunnel engineering technology, specifically a tunnel initial support enlargement foot unit component. Background Technology
[0002] In the construction of tunnels in weak surrounding rock sections, such as shallow-buried sections of Class V surrounding rock, soft rock sections, or sections requiring local reinforcement, controlling problems such as overall settlement of the tunnel arch, settlement of the arch foot, severe convergence, excessive deformation, and collapse is particularly important. Generally, due to insufficient bearing capacity and rigidity of the surrounding rock, the arch foot of the tunnel's initial support will settle, leading to an expansion of the loose area of the surrounding rock. This increases the load on the initial support and causes large deformations in the surrounding rock, resulting in insufficient secondary lining thickness or inadequate tunnel clearance. To address this, tunnel builders have summarized several engineering measures for preventing and treating excessive deformation in tunnels with weak surrounding rock through long-term theoretical research and engineering practice, achieving significant results. These measures include grouting to reinforce the weak surrounding rock mass, increasing the rigidity of the initial support, and adding long anchor bolts and locking anchor bolts. However, these methods all have their applicable scope and conditions, as well as certain limitations. Exploring more simple, economical, and effective engineering technologies remains the mission of many technical workers.
[0003] Expanding the support area and increasing the stiffness of the initial support arch foot of a tunnel is a new technology that has emerged in recent years. Its core technology involves increasing the support area and stiffness of the initial support arch foot, and stabilizing the surrounding rock at the initial support foot. Expanding the support area reduces stress concentration, lowers the load requirements on the bearing capacity of the surrounding rock at the arch foot, reduces arch foot settlement, and reduces the area of loosened surrounding rock caused by settlement, thereby reducing the load on the initial support structure from the loose surrounding rock. Increasing the stiffness of the initial support directly improves its bearing capacity and resistance to deformation. Especially under conditions of weak surrounding rock, high ground water content, and water accumulation at the arch foot, expanding the support area and increasing the stiffness of the initial support arch foot are highly effective in controlling severe convergence and overall settlement of the arch crown and ground surface. This significantly improves construction efficiency, eliminates the need for other auxiliary construction measures, and saves manpower and resources. Utility Model Content
[0004] To address the shortcomings of existing technologies, this utility model provides a tunnel initial support enlargement foot unit component, which is suitable for soft surrounding rock tunnels constructed using the three-step method. It can enlarge the support area of the tunnel initial support arch foot, improve the stiffness of the initial support, and stabilize the surrounding rock around the initial support foot. It has a good effect on controlling problems such as overall settlement of the tunnel arch crown, settlement of the arch foot, severe convergence, excessive deformation, and collapse.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A segmental unit component for expanding the foot of a tunnel initial support, acting on the tunnel initial support structure, is a segmental unit component in the tunnel initial support arch frame, located at the arch foot of the upper half section of the tunnel initial support. It consists of an arch frame upright, an arch frame diagonal brace, an arch frame bottom foot rod, a connecting steel plate, and a bottom foot steel plate. The ends of one arch frame upright, one arch frame diagonal brace, and one arch frame bottom foot rod are welded together to form a triangular structure. A connecting steel plate is welded to each of the two ends of the arch frame upright; and a bottom foot steel plate is welded to the bottom end of the arch frame diagonal brace.
[0007] A further preferred technical solution is that the arch frame upright is an I-beam processed into the arc shape of the tunnel cross section, with the two end sections orthogonal to the axis of the arch frame upright, and the length of the arch frame upright is equal to the arc length of the initial support enlarged leg unit.
[0008] A further preferred technical solution is that: the arch frame diagonal brace is a straight I-beam with one end cut into an arc-shaped cross-section and the other end cross-section orthogonal to the axis of the arch frame diagonal brace; the length of the arch frame diagonal brace is less than the arc length of the initial support expansion leg unit; the arc-shaped cross-section end of the arch frame diagonal brace is welded to the top end of the arch frame upright, and the axis of the arch frame diagonal brace is tangent to the arc of the top end of the arch frame upright.
[0009] A further preferred technical solution is that: the arch frame base rod is a straight I-beam with one end cut into an arc-shaped cross-section and the other end cross-section orthogonal to the axis of the arch frame base rod. The length of the arch frame base rod is equal to the width of the "V"-shaped opening formed after the arch frame upright and the arch frame diagonal brace are welded together. The arch frame base rod is welded to the base of the arch frame upright and the arch frame diagonal brace respectively to form a stable triangular structure. During welding, the shape of the two ends of the arch frame base rod can be appropriately modified according to the actual situation to facilitate connection.
[0010] A further preferred technical solution is as follows: the connecting steel plate is a rectangular steel plate with a size larger than the cross-sectional size of the arch support column. The thickness of the steel plate meets the connection stiffness requirements. Four bolt holes are drilled at the four corners of the rectangular steel plate. The position of the bolt holes should match that of other units of the arch frame to facilitate the passage of bolts, and should avoid the web and flange positions of the arch frame I-beams. The diameter of the bolt holes should match or be slightly larger than the diameter of the connecting bolts used. The connecting steel plate is welded to the two ends of the arch support column and can be connected to other unit components of the tunnel initial support arch frame by bolts.
[0011] A further preferred technical solution is that: the base steel plate is a rectangular steel plate with a size larger than the cross-sectional size of the arch frame diagonal brace, and the thickness of the steel plate meets the connection stiffness requirements; the base steel plate is welded to the base end of the arch frame diagonal brace and supported on the bedrock of the enlarged arch foot.
[0012] The beneficial effects of this utility model are:
[0013] (1) It can expand the support area of the initial support arch foot of the tunnel, improve the stiffness of the initial support, and stabilize the surrounding rock of the initial support foot. It has a good effect on controlling the overall subsidence of the tunnel arch, the subsidence of the arch foot, severe convergence, excessive deformation, collapse and other problems.
[0014] (2) The components are manufactured in the factory. All rods and accessories are welded together outside the tunnel to form a whole, which reduces the construction time inside the tunnel, improves the construction progress and project quality, and improves the construction environment inside the tunnel.
[0015] (3) It is safe and reliable, easy to operate, and takes into account the requirements of safety, quality, schedule, economic benefits and social benefits. Attached Figure Description
[0016] Figure 1 This is a schematic diagram showing the location of this utility model in the overall structure of the tunnel's initial support;
[0017] Figure 2 This is a schematic diagram of the overall structure of the present invention;
[0018] Figure 3 This is a schematic diagram of the arch frame upright structure of this utility model;
[0019] Figure 4 This is a schematic diagram of the arch frame diagonal brace structure of this utility model;
[0020] Figure 5 This is a schematic diagram of the arch frame base rod structure of this utility model;
[0021] Figure 6 This is a schematic diagram of the connecting steel plate structure of this utility model;
[0022] Figure 7 This is a schematic diagram of the base steel plate structure of this utility model;
[0023] In the diagram: Unit AE represents the various units of the tunnel initial support arch frame, 1-arch frame upright, 2-arch frame diagonal brace, 3-arch frame base rod, 4-connecting steel plate, 5-base steel plate, 6-bolt hole. Detailed Implementation
[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0025] exist Figure 1 In this context, a tunnel initial support enlargement foot unit component acts on the tunnel initial support structure. It is a segmental unit component (such as unit B) in the tunnel initial support arch frame, located at the arch foot of the upper half section of the tunnel initial support. It can be connected to other unit components (such as unit A and unit C) of the tunnel initial support arch frame by bolts.
[0026] exist Figure 2 In this invention, a tunnel initial support expansion foot unit component is composed of an arch frame upright 1, an arch frame diagonal brace 2, an arch frame bottom foot rod 3, a connecting steel plate 4, and a bottom foot steel plate 5. An arch frame upright 1, an arch frame diagonal brace 2, and an arch frame bottom foot rod 3 are welded together at their ends to form a triangular structure. A connecting steel plate 4 is welded to each of the two ends of the arch frame upright 1. A bottom foot steel plate 5 is welded to the bottom end of the arch frame diagonal brace 2.
[0027] In Figure 3, the arch support pole 1 is an I-beam machined into the arc shape of the tunnel cross section. The two end sections are orthogonal to the axis of the arch support pole 1, and the length of the arch support pole 1 is equal to the arc length of the initial support enlarged leg unit.
[0028] exist Figure 4 In this design, the arch frame diagonal brace 2 is a straight I-beam with one end cut into an arc-shaped cross section and the other end cross section orthogonal to the axis of the arch frame diagonal brace 2. The length of the arch frame diagonal brace 2 is less than the arc length of the initial support expansion leg unit. The arc-shaped cross section end of the arch frame diagonal brace 2 is welded to the top end of the arch frame upright 1, and the axis of the arch frame diagonal brace 2 is tangent to the arc of the top end of the arch frame upright 1.
[0029] exist Figure 5 In this context, the arch frame base rod 3 is a straight I-beam with one end cut into an arc-shaped cross-section and the other end cross-section orthogonal to the axis of the arch frame base rod 3. The length of the arch frame base rod 3 is equal to the width of the "V"-shaped opening formed after the arch frame upright rod 1 and the arch frame diagonal brace rod 2 are welded together. The arch frame base rod 3 is welded to the base of the arch frame upright rod 1 and the arch frame diagonal brace rod 2 respectively to form a stable triangular structure. During welding, the shape of the two ends of the arch frame base rod 3 can be appropriately modified according to the actual situation to facilitate connection.
[0030] exist Figure 6In this design, the connecting steel plate 4 is a rectangular steel plate with dimensions larger than the cross-sectional dimensions of the arch support pole 1. The thickness of the steel plate meets the connection stiffness requirements. Four bolt holes 6 are drilled at the four corners of the rectangular steel plate. The positions of the bolt holes 6 should match those of other units of the arch frame to facilitate the passage of bolts, and should avoid the web and flange positions of the arch frame I-beams. The diameter of the bolt holes 6 should match or be slightly larger than the diameter of the connecting bolts used. The connecting steel plate 4 is welded to the two ends of the arch support pole 1 and can be connected to other unit components of the tunnel initial support arch frame through bolts.
[0031] exist Figure 7 In this context, the base steel plate 5 is a rectangular steel plate with a size larger than the cross-sectional size of the arch frame diagonal brace 2, and the thickness of the steel plate meets the connection stiffness requirements; the base steel plate 5 is welded to the base end of the arch frame diagonal brace 2 and supported on the bedrock of the enlarged arch foot.
[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A tunnel initial support expansion unit component, comprising an arch frame upright (1), an arch frame diagonal brace (2), an arch frame bottom support (3), a connecting steel plate (4), and a bottom support steel plate (5), characterized in that: An arch frame upright (1), an arch frame diagonal brace (2), and an arch frame base rod (3) are welded together at their ends to form a triangular structure; a connecting steel plate (4) is welded to each of the two ends of the arch frame upright (1); a base steel plate (5) is welded to the bottom end of the arch frame diagonal brace (2).
2. The tunnel initial support enlargement foot unit component according to claim 1, characterized in that: The arch support pole (1) is an I-beam processed into the arc shape of the tunnel cross section. The two end sections are orthogonal to the axis of the arch support pole (1). The length of the arch support pole (1) is equal to the arc length of the initial support enlarged leg unit.
3. A tunnel initial support enlargement foot unit component according to claim 1, characterized in that: The arch frame diagonal brace (2) is a straight I-beam with one end cut into an arc-shaped cross section and the other end cross section orthogonal to the axis of the arch frame diagonal brace (2). The length of the arch frame diagonal brace (2) is less than the arc length of the initial support expansion leg unit. The arc-shaped cross section end of the arch frame diagonal brace (2) is welded to the top end of the arch frame upright (1), and the axis of the arch frame diagonal brace (2) is tangent to the arc of the top end of the arch frame upright (1).
4. A tunnel initial support enlargement foot unit component according to claim 1, characterized in that: The arch frame base rod (3) is a straight I-beam with one end cut into an arc-shaped cross section and the other end cross section orthogonal to the axis of the arch frame base rod (3). The length of the arch frame base rod (3) is equal to the width of the "V" shaped opening formed after the arch frame upright rod (1) and the arch frame diagonal brace rod (2) are welded together. The arch frame base rod (3) is welded to the bottom end of the arch frame upright rod (1) and the arch frame diagonal brace rod (2) respectively to form a stable triangular structure.
5. A tunnel initial support enlargement foot unit component according to claim 1, characterized in that: The connecting steel plate (4) is a rectangular steel plate with a size larger than the cross-sectional size of the arch support (1). The thickness of the steel plate meets the connection stiffness requirements. Four bolt holes (6) are drilled at the four corners of the rectangular steel plate. The position of the bolt holes (6) should match the other units of the arch frame to facilitate the passage of bolts, and should avoid the web and flange positions of the arch frame I-beam. The diameter of the bolt holes (6) should match or be larger than the diameter of the connecting bolts used. The connecting steel plate (4) is welded to the two ends of the arch support (1) and can be connected to other unit components of the tunnel initial support arch frame through bolts.
6. A tunnel initial support enlargement foot unit component according to claim 1, characterized in that: The foot steel plate (5) is a rectangular steel plate with a size larger than the cross-sectional size of the arch frame diagonal brace (2), and the thickness of the steel plate meets the connection stiffness requirements; the foot steel plate (5) is welded to the foot end of the arch frame diagonal brace (2) and supported on the bedrock of the enlarged arch foot.