A tunnel face front fault fracture zone grating type reinforcing structure

Abstract

This utility model relates to a grid-type reinforcement structure for a fault fracture zone in front of a tunnel face, belonging to the field of tunnel construction technology; it includes: a grid-type reinforcement body, in which multiple rows of first grouting grooves are opened laterally on the face behind the fault fracture zone, and multiple rows of second grouting grooves are opened longitudinally on the face. The first and second grouting grooves are interlaced to form a grid-type cavity, and both the first and second grouting grooves are filled with grouting liquid to form the grid-type reinforcement body; and anchor bolts, in which multiple grouting holes are opened on the grid-type reinforcement body, the grouting holes are located at the intersection of the first and second grouting grooves, and the anchor bolts are fixedly installed in the grouting holes by grouting; the grid-type reinforcement body is formed by the first and second grouting grooves, and the anchor bolts are inserted at the intersection of the first and second grouting grooves, forming an integrated support structure of "grid bearing pressure and anchor bolt transmitting force", which enhances the support force and stability of the reinforcement structure.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, and in particular to a grid-type reinforcement structure for fault fracture zones in front of the tunnel face. Background Technology

[0002] In the field of tunnel engineering construction, fault fracture zones are a common and complex geological structural phenomenon. These geological structures exhibit significant geological characteristics, with highly fractured rocks, a loose and disordered structure, significantly reduced rock strength, and are usually accompanied by relatively active groundwater activity.

[0003] When tunnel construction needs to traverse geologically challenging areas such as fault fracture zones, the extremely poor stability of the surrounding rock can easily trigger a series of severe geological disasters. For example, large-scale collapses of the surrounding rock mass or frequent rockfalls may occur. These geological disasters not only pose a direct and serious threat to the lives of construction workers, potentially resulting in casualties, but also significantly hinder the tunnel construction progress, causing delays and increasing project costs. Furthermore, they can have a substantial impact on the tunnel's overall quality, reducing its stability and durability.

[0004] Currently, widely used advanced pre-reinforcement technologies mainly include advanced small-diameter pipe grouting, advanced anchor bolts, and horizontal jet grouting piles. However, these traditional methods still have certain limitations when dealing with complex, large-scale, or water-rich high-pressure fault fracture zones. For example, the anchor bolt support system lacks systematicity: conventional advanced anchor bolts are usually driven into the fracture zone in a single or multiple parallel arrangement. In this way, there is a lack of effective lateral and longitudinal connections between the anchor bolts, making it difficult to form an integral support structure. Its function mainly relies on the anchoring of individual bolts and the beam effect, which has limited effectiveness in resisting the pressure transmission from the surrounding rock behind the tunnel face and maintaining the overall stability of the fracture zone, especially when the fracture zone is large. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a grid-type reinforcement structure for the fault fracture zone in front of the tunnel face. This structure solves the problem that traditional reinforcement methods lack effective lateral and longitudinal connections between anchor bolts, making it difficult to form an integral support structure and limiting their effectiveness in resisting the pressure transmission from the surrounding rock behind the tunnel face and maintaining the overall stability of the fracture zone.

[0006] To achieve the above objectives, this utility model provides a grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face, comprising:

[0007] The grid-type reinforced body has multiple rows of first grouting grooves opened laterally on the tunnel face behind the fault fracture zone, and multiple columns of second grouting grooves opened longitudinally on the tunnel face. Both the first and second grouting grooves extend deep along the tunnel excavation direction. The first and second grouting grooves intersect each other to form a grid-type cavity. Both the first and second grouting grooves are filled with grouting liquid to form a grid-type reinforced body.

[0008] The anchor bolt has multiple grouting holes on the grid-type reinforcement body. The grouting holes are located at the intersection of the first grouting groove and the second grouting groove. Each grouting hole extends into the hard rock stratum along the tunnel excavation direction. The anchor bolt is fixedly installed in the grouting hole by grouting.

[0009] This configuration forms a grid-like reinforced structure through the first and second grouting grooves. Anchor bolts are then inserted at the intersection of the first and second grouting grooves, creating an integrated support structure where the grid bears pressure and the anchor bolts transmit force, thus enhancing the support strength and stability of the reinforced structure.

[0010] Furthermore, an anchor plate is detachably connected to one end of the anchor rod near the working face, and a locking nut is threaded onto the anchor rod, with the anchor plate abutting between the working face and the locking nut.

[0011] Furthermore, a spherical washer is provided between the locking nut and the anchor plate.

[0012] Furthermore, adjacent anchor plates are connected by a connecting plate.

[0013] Furthermore, each of the four corners of the anchor plate is threaded with an adjusting screw, the end of which abuts against the working face.

[0014] Furthermore, the anchor plate is provided with a first threaded through hole, and the two ends of the connecting plate are symmetrically provided with second threaded through holes. The connecting plate spans between two adjacent anchor plates, and the two second threaded through holes are respectively aligned with the two adjacent first threaded through holes.

[0015] Both ends of the connecting plate are provided with connecting screws, which pass through the second threaded through hole and the first threaded through hole in sequence, and the connecting screws are threadedly connected to the first threaded through hole.

[0016] Furthermore, the anchor bolt is configured as a segmented anchor bolt, comprising multiple anchor bolt segments, which are detachably connected to adjacent anchor bolt segments.

[0017] Furthermore, a threaded sleeve is fixedly connected to one end of the anchor bolt segment, and the threaded sleeve is threadedly connected to one end of the adjacent anchor bolt segment.

[0018] Furthermore, the end dimension of the grouting hole is larger than the diameter dimension of the anchor rod.

[0019] The beneficial effects of this embodiment are as follows:

[0020] 1. A grid-type reinforced body is formed by the first grouting groove and the second grouting groove. Anchor rods are then inserted at the intersection of the first grouting groove and the second grouting groove, forming an overall support structure of "grid bearing pressure and anchor rod transmitting force", which enhances the support force and stability of the reinforced structure.

[0021] 2. By adjusting the screws, ensure that all anchor plates are located on the same vertical plane, so that all anchors can work together to form an integrated support system;

[0022] 3. By setting a spherical washer between the locking nut and the anchor plate, the anchor rod can be deflected within a certain angle, ensuring that the tension always acts perpendicularly on the anchor plate, so that the pressure is evenly distributed on the rock surface, which greatly improves the stress efficiency and adaptability to complex working conditions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the first overall structure of the grid-type reinforcement structure for the fault fracture zone in front of the tunnel face, according to an embodiment of the present utility model.

[0024] Figure 2 This is a cross-sectional view of the grid-type reinforcement structure for the fault fracture zone in front of the tunnel face according to an embodiment of the present invention.

[0025] Figure 3 This is an embodiment of the present utility model. Figure 2 Enlarged schematic diagram of the structure of part A in the middle;

[0026] Figure 4 This is a schematic diagram of the second overall structure of the grid-type reinforcement structure for the fault fracture zone in front of the tunnel face, according to an embodiment of the present invention.

[0027] Among them, the grid-type reinforced body 1, the working face 10, and the tunnel 11;

[0028] Anchor bolt segment 2, threaded sleeve 20, adjusting screw 21, anchor plate 22, locking nut 23, connecting screw 24, connecting plate 25, first threaded through hole 26, spherical washer 27. Detailed Implementation

[0029] The specific embodiments of this utility model will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the utility model. In the following description, numerous specific details are set forth in order to provide a thorough understanding of this utility model. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement this utility model. In other instances, well-known circuits, software, or methods have not been specifically described in order to avoid obscuring the utility model.

[0030] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0031] Please see Figure 1-4 This utility model provides an embodiment of a grid-type reinforcement structure for a fault fracture zone in front of a tunnel face, comprising: a grid-type reinforcement body 1, wherein multiple rows of first grouting grooves are opened laterally on the tunnel face 10 behind the fault fracture zone, and multiple rows of second grouting grooves are opened longitudinally on the tunnel face 10, wherein the first and second grouting grooves extend into the tunnel 11 along the excavation direction, and the first and second grouting grooves intersect to form a grid-type cavity, and both the first and second grouting grooves are filled with grouting liquid to form the grid-type reinforcement body 1; and anchor bolts, wherein multiple grouting holes are opened on the grid-type reinforcement body 1, the grouting holes are located at the intersection of the first and second grouting grooves, each grouting hole extends into the hard rock stratum along the excavation direction of the tunnel 11, and the anchor bolts are fixedly installed in the grouting holes by grouting. During construction, grout is injected into the first and second grouting trenches. The grout can be selected according to the actual situation, and cement grout can be selected. After the grout solidifies, the first and second grouting trenches form a grid-like reinforced body 1, which directly provides support to the tunnel face 10. Then, anchor rods are inserted into the newly opened grouting holes, and cement grout is injected into the grouting holes to fix the anchor rods. Thus, after initial fixation by the grid-like reinforced body 1, the anchor rods extending into the hard rock layer provide anchoring force to the grid-like reinforced body 1, tightly connecting the tunnel surrounding rock and the grid-like reinforced body 1 into a whole, effectively limiting the deformation and displacement of the surrounding rock and improving the overall stability of the tunnel structure.

[0032] This embodiment forms a grid-like reinforcement framework through the first and second grouting grooves, integrating the entire reinforcement area into a cohesive, synergistic mesh structure, rather than isolated "grout veins" or scattered rods. This solves the problem of the integrity of the reinforcement body, forming a high-strength spatial grid system. Simultaneously, this embodiment organically and three-dimensionally combines the planar support of the grid-type reinforcement body with the deep point anchoring of the anchor bolts, forming a collaborative working mechanism of "grid bearing pressure, anchor bolt transmitting force," which can also control the extrusion deformation of the working face 10 and the shear slippage of the deep surrounding rock.

[0033] In this embodiment, an anchor plate 22 is detachably connected to one end of the anchor rod near the working face 10, and a locking nut 23 is threaded onto the anchor rod. The anchor plate 22 abuts against the working face 10 and the locking nut 23. After grouting is completed, the anchor plate 22 is fixed to the anchor rod by the locking nut 23, which enhances the flexibility and adaptability of construction.

[0034] In this embodiment, a spherical washer 27 is provided between the locking nut 23 and the anchor plate 22. During actual construction, the anchor rod may not be perfectly perpendicular to the working face 10. This embodiment adds a spherical washer 27 between the locking nut 23 and the anchor plate 22, allowing the anchor rod to deflect within a certain angle, ensuring that the tension always acts perpendicularly on the anchor plate 22. This results in a uniform distribution of pressure on the rock surface, greatly improving stress efficiency and adaptability to complex working conditions.

[0035] In this embodiment, adjacent anchor plates 22 are connected by connecting plates 25. In use, connecting all anchor plates 22 on the face 10 into a single unit provides a significant synergistic support effect, increasing overall rigidity. Furthermore, when a particular anchor bolt is subjected to excessive stress, the connecting plates 25 can transfer some of the load to adjacent anchor plates 22, preventing stress concentration at a single point. Additionally, the integrally connected anchor plates 22 can form a "pressure arch" effect, dispersing the surrounding rock pressure at the face 10 to the surrounding support system and reducing the risk of localized collapse.

[0036] In this embodiment, each of the four corners of the anchor plate 22 is threaded with an adjusting screw 21, the end of which abuts against the working face 10. When installing the anchor plate 22, the adjusting screw 21 is used to adjust the anchor plate 22 to a vertical plane and level it with adjacent anchor plates 22, ensuring they are on the same vertical plane. This ensures all anchors work together to form an integrated support system. That is, when all anchor plates are on the same plane, after applying the same torque (preload) to the nuts, the preload generated by each anchor and the compression effect on the surrounding rock are essentially the same. This allows them to evenly distribute the pressure from the surrounding rock, forming a stable "pressure-bearing arch," ensuring uniform distribution of prestress, actively controlling surrounding rock deformation, and eliminating harmful bending moments, keeping the anchors in a purely tensile state. In actual construction, the working face 10 may have slight inclination or unevenness, but this can be manually controlled within a certain range. For example, after preliminary cleaning of the uneven working face, a mesh can be directly attached and a layer of concrete sprayed, naturally forming a flat working surface. Then, the adjusting screw 21 is used to level each anchor plate 22 on the same vertical plane.

[0037] In this embodiment, the anchor plate 22 has a first threaded through hole 26, and the connecting plate 25 has symmetrical second threaded through holes at both ends. The connecting plate 25 spans between two adjacent anchor plates 22, and the two second threaded through holes are respectively aligned with the two adjacent first threaded through holes 26. Connecting screws 24 are provided at both ends of the connecting plate 25, passing through the second threaded through holes and the first threaded through holes 26 in sequence, and are threadedly connected to the first threaded through holes 26. After the anchor plates 22 are installed, the connecting plate 25 is placed on the two adjacent anchor plates 22, and the corresponding first threaded through holes 26 and second threaded through holes are aligned. Finally, the connecting plate 25 is locked to the two adjacent anchor plates 22 by the connecting screws 24, thereby achieving the effect of fixing the connecting anchor plates 22, effectively enhancing the integrity and stability of the entire anchor bolt support system, and enabling it to better withstand external loads. For example, when subjected to external forces, the load can be evenly transferred to adjacent anchor bolts through the connecting plate 25 and connecting screw 24, avoiding stress concentration and reducing the risk of support structure failure due to uneven local stress. Simultaneously, the threaded connection method makes operation simple and convenient, facilitating disassembly and replacement. In practical use, the length of the connecting plate 25 can be designed and adjusted according to the spacing of adjacent anchor bolts, adapting to different arrangements of anchor bolts and anchor plates 22. During practical use, locking nuts can be threaded onto both ends of the connecting screw 24 to prevent loosening, making the connection between adjacent anchor plates 22 more secure.

[0038] In this embodiment, the anchor bolt is configured as a segmented anchor bolt, comprising multiple anchor bolt segments 2, which are detachably connected. During use, it can be quickly assembled into a suitable length according to site conditions, providing strong flexibility and increasing the adaptability of the anchor bolt. Furthermore, the segmented anchor bolt is also suitable for storage and transportation.

[0039] In this embodiment, a threaded sleeve 20 is fixedly connected to one end of an adjacent anchor bolt segment 2, and the threaded sleeve 20 is threadedly connected to one end of the adjacent anchor bolt segment 2. In use, the threaded sleeve 20 is used to fix two adjacent anchor bolt segments 2 together, ensuring a firm connection. In actual use, the threaded sleeve 20 can be made of high-strength alloy steel (such as 42CrMo), with a shear strength ≥ 120% of the anchor bolt axial force, ensuring stress is transferred without loss at the joint. In actual use, one end of each anchor bolt segment 2 is provided with external threads, and the other end of each anchor bolt segment 2 is fixedly connected to a threaded sleeve 20 with matching internal threads, thereby facilitating the connection between two anchor bolt segments 2.

[0040] In this embodiment, the end dimension of the grouting hole is larger than the diameter of the anchor rod. During grouting, the grout can fully fill the gap between the anchor rod and the hole wall, especially forming a large grout inclusion at the end of the hole. After solidification, this inclusion provides a larger anchoring area, acting like a larger "grip" to hold the anchor rod, thereby significantly increasing the friction and adhesion between the anchor rod and the surrounding medium, and improving the anchoring force of the anchor rod.

[0041] The specific construction method in this embodiment is as follows:

[0042] During construction, multiple rows of first grouting grooves are opened horizontally, and multiple columns of second grouting grooves are opened vertically. Grouting is carried out simultaneously during grooving. After the grout solidifies, a grid-like reinforced body 1 is obtained. Grouting holes are then opened at the intersection of the first and second grouting grooves, and multiple anchor segments 2 are connected to form anchors of the required length as needed. The anchors are then inserted into the newly opened grouting holes, and cement grout is injected into the grouting holes to fix the anchors.

[0043] After the anchor rod is fixed, the anchor plate 22 is installed on the anchor rod, and the anchor plate is leveled using the adjusting screw 21. The spherical washer 27 is fitted on the anchor rod, i.e., on the anchor plate 22. Then, the anchor plate 22 is locked using the locking nut 23. After all the anchor plates 22 are installed and leveled, the connecting plate 25 is placed on two adjacent anchor plates 22, and the corresponding first threaded through hole 26 and second threaded through hole are aligned. Finally, the connecting plate 25 is locked on the two adjacent anchor plates 22 using the connecting screw 24 until all the anchor plates 22 are connected as one unit.

[0044] In summary, this utility model forms a grid-type reinforced structure 1 through the first and second grouting grooves, and then inserts anchor rods at the intersection of the first and second grouting grooves, forming an integrated support structure of "grid bearing pressure and anchor rod transmitting force," which enhances the supporting force and stability of the reinforced structure. Therefore, this utility model effectively overcomes the various shortcomings of the prior art.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A grid-type reinforcement structure for fault fracture zones ahead of a tunnel face, characterized in that, include: The grid-type reinforced body has multiple rows of first grouting grooves opened laterally on the tunnel face behind the fault fracture zone, and multiple columns of second grouting grooves opened longitudinally on the tunnel face. The first grouting grooves and the second grouting grooves are both extended into the tunnel excavation direction. The first grouting grooves and the second grouting grooves are interlaced to form a grid-type cavity. The first grouting grooves and the second grouting grooves are filled with grouting liquid to form a grid-type reinforced body. The anchor bolt has multiple grouting holes on the grid-type reinforcement body. The grouting holes are located at the intersection of the first grouting groove and the second grouting groove. Each grouting hole extends into the hard rock stratum along the tunnel excavation direction. The anchor bolt is fixedly installed in the grouting hole by grouting.

2. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 1, characterized in that: An anchor plate is detachably connected to one end of the anchor rod near the working face, and a locking nut is threaded onto the anchor rod. The anchor plate abuts against the working face and the locking nut.

3. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 2, characterized in that: A spherical washer is provided between the locking nut and the anchor plate.

4. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 2, characterized in that: The adjacent anchor plates are connected by a connecting plate.

5. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 4, characterized in that: Each of the four corners of the anchor plate is threaded with an adjusting screw, the end of which abuts against the working face.

6. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 5, characterized in that: The anchor plate is provided with a first threaded through hole, and the two ends of the connecting plate are symmetrically provided with second threaded through holes. The connecting plate spans between two adjacent anchor plates, and the two second threaded through holes are respectively aligned with the two adjacent first threaded through holes. Both ends of the connecting plate are provided with connecting screws, which pass through the second threaded through hole and the first threaded through hole in sequence, and the connecting screws are threadedly connected to the first threaded through hole.

7. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 1, characterized in that: The anchor bolt is configured as a segmented anchor bolt, which includes multiple anchor bolt segments, and adjacent anchor bolt segments are detachably connected.

8. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 7, characterized in that: One end of the anchor bolt segment is fixedly connected to a threaded sleeve, and the threaded sleeve is threadedly connected to one end of the adjacent anchor bolt segment.

9. The grid-type reinforcement structure for the fault fracture zone ahead of the tunnel face according to claim 1, characterized in that: The end dimension of the grouting hole is larger than the diameter dimension of the anchor rod.

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