Tunnel third-grade near horizontal surrounding rock anti-collapse structure

Abstract

The utility model relates to a surrounding rock support technical field, especially in a tunnel III level near horizontal surrounding rock anti -caving structure, including steel pipe arch, the concrete layer is spouted on steel pipe arch, steel pipe arch is constituted by multiple steel pipe rings along the longitudinal distribution of tunnel, and the adjacent steel pipe ring is connected through reinforcing steel bar, and the steel pipe ring is constituted by multiple sections of steel pipe that pour cement mortar in the inside, and the same ring steel pipe joint is connected through the screw sleeve, and the steel pipe ring arch foot place is welded with angle steel, and the steel pipe ring same side arch foot is welded as a whole through the steel pad, and the bearing capacity and the overall stability are strengthened. Through adjusting the original part system anchor rod layout position, as the lock foot anchor rod will steel pipe arch and surrounding rock anchor, not only reinforce the steel pipe arch, but also save the cost, under the condition of not increasing the initial support concrete thickness, through the steel pipe arch and the thin layer of concrete synergic deformation and common force, inhibit near horizontal rock bed delamination and the chunk, improve the overall stability, and the construction is convenient, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of surrounding rock support technology, and in particular to a near-horizontal surrounding rock anti-collapse structure for Class III tunnels. Background Technology

[0002] With the development of transportation infrastructure, various tunnel construction challenges urgently need to be addressed. The initial support of Class III surrounding rock in tunnels is usually supported by shotcrete and systematic anchor bolts. The initial support is not supported by arch frames. However, under the long-term repeated influence of blasting vibration, this section of the initial support is prone to delamination and collapse along the rock stratum structure. In the case of developed secondary joints, the main structural surface and secondary joints interact and influence each other, making it easier to form wedge-shaped blocks. However, such block collapses are generally difficult to predict, posing a great risk to construction safety.

[0003] Traditional support methods often involve adding arch frames, which can improve stability to some extent, but also leads to an increase in the thickness of the initial support concrete, higher costs, and a longer construction period.

[0004] Therefore, there is an urgent need for a new type of support structure that is anti-collapse, economical, efficient, and easy to construct, in order to solve the technical problems of existing support methods being conservative, having long construction periods, high costs, and high construction investment risks. Utility Model Content

[0005] The purpose of this utility model is to provide a Class III near-horizontal surrounding rock anti-collapse structure for tunnels, so as to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides a tunnel Class III near-horizontal surrounding rock anti-collapse structure, including a steel pipe arch frame, the steel pipe arch frame being anchored to the tunnel surrounding rock, the steel pipe arch frame being sprayed with a concrete layer, the steel pipe arch frame being composed of several longitudinally adjacent steel pipe rings connected to each other, each steel pipe ring being composed of several sections of steel pipe connected to each other by threaded sleeves, and the inside of the steel pipe being filled with cement mortar.

[0007] Preferably, the steel pipe rings are arranged at equal intervals along the longitudinal direction of the tunnel, and adjacent steel pipe rings are longitudinally connected by several reinforcing bars.

[0008] Preferably, a number of the steel bars are evenly distributed along the annular intervals of the tunnel.

[0009] Preferably, angle steel is welded to the arched feet at both ends of each steel pipe ring, and the arched feet on the same side of each steel pipe ring are welded to the steel pad as a whole, wherein the angle steel is welded to the steel pad.

[0010] Preferably, each of the steel pipe rings is fixedly connected to the surrounding rock of the tunnel by a number of locking anchor rods. A locking anchor rod is installed at the arch shoulder, arch waist and arch foot on both sides of the steel pipe ring. The locking anchor rods are the system anchor rods of the original shotcrete support.

[0011] Preferably, the overall longitudinal length of the steel pipe arch frame is 5m, the spacing between adjacent steel pipe rings arranged longitudinally is 1m, and the spacing between adjacent reinforcing bars in the circumferential direction is 1m.

[0012] Preferably, the thickness of the concrete layer is 10 cm.

[0013] Therefore, the present invention provides a tunnel Class III near-horizontal surrounding rock anti-collapse structure with the following beneficial effects: by fully utilizing the characteristics of rigidity and flexibility, coordinated deformation and joint stress of shotcrete and concrete steel pipe arch without increasing the thickness of the initial support shotcrete, the stability of the near-horizontal rock strata of the tunnel arch is ensured. At the same time, the existing tunnel system anchors are fully utilized, and some of the original system anchors are adjusted to lock-foot anchors of concrete steel pipes, which enhances the stability of concrete steel pipes, suppresses delamination and rockfall of the arch rock strata, improves the overall stability of the tunnel, reduces construction safety risks, and at the same time, significantly reduces material costs, controls engineering change costs, and reduces construction investment risks.

[0014] By connecting each steel pipe section with threaded sleeves and longitudinal steel bars to form an overall frame structure, it is easy to prefabricate in the factory and hoist the entire structure, which improves construction efficiency, shortens the construction period, reduces on-site welding work, and reduces construction difficulty and safety risks.

[0015] Angle steel and steel pads are welded together at the arch foot to increase the bottom load-bearing area, improve the structure's load-bearing capacity and stability, and facilitate overall movement and positioning, thus providing high construction flexibility. Attached Figure Description

[0016] Figure 1 This is a schematic elevation view of a tunnel Class III near-horizontal surrounding rock anti-collapse structure according to an embodiment of this utility model;

[0017] Figure 2 This is a side view of a tunnel Class III near-horizontal surrounding rock anti-collapse structure according to an embodiment of this utility model;

[0018] Figure 3 This is a schematic diagram of a steel pipe joint connected in the same circumferential direction;

[0019] Figure 4 This is a schematic elevation view of the arch foot boots and steel pads on both sides of the steel pipe arch frame;

[0020] Figure 5 This is a plan view of the arch foot boots and steel pads on both sides of the steel pipe arch frame;

[0021] Figure Labels

[0022] 1. Steel pipe arch frame; 2. Concrete layer; 3. Steel pipe ring; 4. Reinforcing bar; 5. Steel pipe; 6. Threaded sleeve; 7. Angle steel; 8. Steel pad; 9. Arch shoulder anchor bolt; 10. Arch waist anchor bolt; 11. Arch foot anchor bolt; 12. System anchor bolt. Detailed Implementation

[0023] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0024] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar words used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Example

[0026] like Figure 1-5 As shown, this utility model discloses a tunnel Class III near-horizontal surrounding rock anti-collapse structure, including a steel pipe arch frame 1, which is anchored to the tunnel surrounding rock. A concrete layer 2 is sprayed on the steel pipe arch frame 1. The steel pipe arch frame 1 is composed of several steel pipe rings 3 arranged adjacent to each other in the longitudinal direction of the tunnel and connected to each other. Each steel pipe ring 3 is spliced ​​from several sections of arc-shaped steel pipes 5. The inside of the steel pipes 5 is filled with cement mortar to greatly improve their bending and compressive bearing capacity. Each section of steel pipe 5 is connected to each other in the circumferential direction of the tunnel by threaded sleeves 6. The connection method of threaded sleeves 6 facilitates rapid on-site assembly and ensures the tightness and integrity of the circumferential connection.

[0027] The steel pipe rings 3 are arranged at equal intervals along the longitudinal direction of the tunnel, and adjacent steel pipe rings 3 are connected longitudinally by several steel bars 4. The steel bars 4 are evenly arranged along the annular interval of the tunnel to firmly connect the adjacent steel pipe rings 3, forming a stable spatial grid frame structure, effectively transferring and distributing loads, and enhancing the overall integrity.

[0028] Angle steel 7 is welded to both ends of the arch foot of each steel pipe ring 3 to form a pipe shoe. All arch feet on the same side of each steel pipe ring 3 are welded together as a whole by a steel pad plate 8. The angle steel 7 is also welded to the steel pad plate 8. This structure enhances the local stiffness and bearing area of ​​the arch foot, effectively prevents stress concentration and arch foot settlement, and improves the overall stability of the structure.

[0029] Each steel pipe ring 3 is connected to the surrounding rock of the tunnel by several anchor bolts. An anchor bolt is installed at the key stress points of the arch shoulder, arch waist, and arch foot on both sides of the steel pipe ring 3, namely the arch shoulder anchor bolt 9, the arch waist anchor bolt 10, and the arch foot anchor bolt 11. These anchor bolts directly utilize some of the system anchor bolts 12 in the original shotcrete support of the tunnel, realizing full utilization of the original support materials, saving costs, and tightly connecting the steel pipe arch frame 1 with the surrounding rock, effectively suppressing the collapse of the surrounding rock.

[0030] In this embodiment, the overall longitudinal length of the steel pipe arch frame 1 is 5m, the spacing between adjacent longitudinal steel pipe rings 3 is 1m, the spacing between adjacent circumferential reinforcing bars 4 is 1m, and the sprayed thickness of the concrete layer 2 is 10cm. This design, while ensuring that the structure has sufficient support rigidity and safety margin, maximizes the control of material usage and initial support thickness, taking into account both economy and safety.

[0031] This utility model discloses a tunnel near-horizontal surrounding rock anti-collapse structure. The thin-layer concrete and the steel pipe arch frame with built-in cement mortar share the force and deform together. It is suitable for dealing with the technical problem of delamination and rockfall in near-horizontal surrounding rock of Class III under the influence of dynamic loads such as blasting vibration. It is easy to construct, cost-controllable, and has good stability, effectively reducing the safety risks during tunnel construction and operation.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A tunnel Class III near-horizontal surrounding rock anti-collapse structure, characterized in that: The system includes a steel pipe arch frame, which is anchored to the surrounding rock of the tunnel. A layer of concrete is sprayed onto the steel pipe arch frame. The steel pipe arch frame is composed of several longitudinally adjacent steel pipe rings connected to each other. Each steel pipe ring is composed of several sections of steel pipe connected to each other by threaded sleeves. The inside of the steel pipes is filled with cement mortar.

2. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 1, characterized in that: The steel pipe rings are arranged at equal intervals along the longitudinal direction of the tunnel, and adjacent steel pipe rings are connected longitudinally by several steel bars.

3. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 2, characterized in that: Several of the aforementioned reinforcing bars are evenly distributed along the annular intervals of the tunnel.

4. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 2, characterized in that: Angle steel is welded to the arched feet at both ends of each steel pipe ring, and the arched feet on the same side of each steel pipe ring are welded to the steel pad as a whole, with the angle steel being welded to the steel pad.

5. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 4, characterized in that: Each of the steel pipe rings is fixedly connected to the surrounding rock of the tunnel by several locking anchor rods. A locking anchor rod is installed at the arch shoulder, arch waist and arch foot on both sides of the steel pipe ring. The locking anchor rods are the original system anchor rods of the shotcrete support.

6. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 5, characterized in that: The overall longitudinal length of the steel pipe arch is 5m, the longitudinal spacing between adjacent steel pipe rings is 1m, and the circumferential spacing between adjacent reinforcing bars is 1m.

7. The tunnel Class III near-horizontal surrounding rock anti-collapse structure according to claim 1, characterized in that: The thickness of the concrete layer is 10cm.

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