Reinforcing structure for fault fracture zone in front of tunnel face

Abstract

The utility model relates to a reinforcing structure for a fault fracture zone in front of a tunnel face, which relates to the technical field of tunnel construction and is used for solving the problems of unclear reinforcing target, unclear reinforcing range, large grouting amount and material waste in the traditional full-section reinforcing method. Comprising a pier-shaped reinforcing body, first grouting holes distributed in a matrix mode are formed in a tunnel face in front of a fault fracture zone, the first grouting holes conduct grouting to form the pier-shaped reinforcing body, one end of the pier-shaped reinforcing body in the tunneling direction is an inclined face, and an acute angle is formed between the end of the pier-shaped reinforcing body and the tunneling direction; a plurality of second grouting holes are formed in the pier-shaped reinforcing body, each second grouting hole goes deep into a hard rock stratum zone in the tunneling direction of the tunnel, and the anchor rods are fixedly installed in the second grouting holes through grouting.

Description

TECHNICAL FIELD

[0001] The utility model relates to a tunnel construction technical field especially to a tunnel face front fault fracture zone reinforcing structure. BACKGROUND

[0002] In the field of tunnel engineering construction, fault fracture zone as a typical and complex geological structure phenomenon exists widely. The geological structure region presents significant geological characteristics, the internal rock broken degree is high, the structure presents loose and disordered state, the rock itself strength reduces obviously, and usually accompanies relatively active underground water activity.

[0003] When the tunnel construction needs to cross the geological difficult problem region of fault fracture zone, because the stability of surrounding rock is very poor, a series of serious geological disasters are easily caused. For example, large-scale collapse of tunnel peripheral rock mass or small rock block frequent falling off etc. These geological disasters not only directly and seriously threaten the life safety of construction personnel, once the accident occurs, personnel casualty is extremely possible; at the same time, the construction progress of tunnel is greatly hindered, the construction period is delayed, the engineering cost is increased; in addition, the influence on the engineering quality of tunnel cannot be ignored, the overall stability and durability of tunnel structure are reduced.

[0004] At present, in the tunnel construction practice, in order to deal with the safety risk of fault fracture zone, the cement grouting of face is generally used for reinforcing treatment. Its main purpose is to improve the strength and integrity of foundation by grouting filling fissure and cementing broken rock mass. The reinforcing mechanism of the reinforced body structure formed by cement grouting is that the grouting liquid can fill various pores and fissures in the fracture zone. Under the grouting pressure, the grouting liquid can squeeze out air and water, plays the role of close filling, makes the structure of broken rock mass become dense, enhances its stability. After the grouting liquid solidifies, the broken rock or soil particles are cemented to form a relatively complete structure, improves the integrity of fracture zone and the mechanical properties. When the grouting pressure reaches a certain degree, the stratum will be split, new fissures are formed, and the grouting liquid will spread and fill. This helps to expand the reinforcing range, makes the integrity of fracture zone better, prevents the loose materials such as broken stone in the fault fracture zone from falling into the tunnel being constructed, thereby ensures the safety of construction personnel's working space and avoids the influence of broken stone falling on the normal construction operation of workers. The traditional face grouting reinforcement adopts full-face grouting reinforcement form, all the broken rock mass in front of the excavation face is grouted and reinforced, and there are problems such as large grouting amount and material waste. In fact, affected by the weight of rock mass, the sliding instability region of broken rock mass is mainly located in the bottom region of tunnel face, the lower part of reinforced body should have enough anti-sliding and anti-deformation capacity, and the surrounding rock pressure on the upper part of reinforced body is small. Therefore, the traditional full-face reinforcement method has the defects of unclear reinforcement target and unclear reinforcement range. Utility model content

[0005] In view of the defects in the prior art, the utility model provides a tunnel face front fault fracture zone reinforcing structure, which is used for solving the problems of unclear reinforcing target, unclear reinforcing range, large grouting amount and material waste of the traditional full-face reinforcing method.

[0006] In order to realize the above-mentioned purpose, the utility model provides a tunnel face front fault fracture zone reinforcing structure, which comprises:

[0007] Pier reinforcing body, the first grouting hole is arranged on the face in the front of the fault fracture zone in a matrix distribution, the first grouting hole is grouted to form the pier reinforcing body, and the pier reinforcing body is inclined at one end along the tunneling direction and forms an acute angle with the tunneling direction;

[0008] Anchor rod, a plurality of second grouting holes are arranged on the pier reinforcing body, each second grouting hole penetrates into the hard rock layer along the tunneling direction, and the anchor rod is fixedly installed in the second grouting hole through grouting.

[0009] In this way, the pier reinforcing body is in the form of a trapezoid with a short upper part and a long lower part, the reinforcing range of the lower part is large, the reinforcing range of the upper part is small, the reinforcing range can be effectively reduced, the reinforcing target is clear, the reinforcing range is definite, the grouting amount is reduced, the material is saved, low-carbon construction of the tunnel project is realized, the anti-sliding and anti-deformation abilities of the pier reinforcing body are utilized to effectively enhance the ability of resisting the overall instability and damage of the fault fracture rock mass, the anchor rod is utilized to reinforce again, the anchoring force is provided, the tunnel surrounding rock and the pier reinforcing body are tightly connected into a whole, the deformation and displacement of the surrounding rock are effectively limited, and the overall stability of the tunnel structure is improved.

[0010] Further, one end of the anchor rod close to the face is detachably connected with an anchor rod pad, and one side of the anchor rod pad abuts against the face.

[0011] Further, the anchor rod pad is sleeved on the anchor rod, a fastening nut is threadedly connected on the anchor rod, and the anchor rod pad abuts between the face and the fastening nut.

[0012] Further, the adjacent anchor rod pads are detachably connected through a connecting piece.

[0013] Further, the connecting piece comprises a connecting plate and a screw rod, a first threaded through hole is arranged on the anchor rod pad, second threaded through holes are symmetrically arranged at both ends of the connecting plate, the connecting plate is arranged on the adjacent two anchor rod pads, and the two second threaded through holes are respectively aligned with the adjacent two first threaded through holes.

[0014] The second threaded through hole is threadedly connected with the screw rod in the corresponding first threaded through hole.

[0015] Further, the anchor rod is provided as a sectional anchor rod, which comprises a plurality of anchor rod segments, and adjacent anchor rod segments are detachably connected.

[0016] Further, one end of the anchor rod segment is fixedly connected with a threaded sleeve, and one end of an adjacent anchor rod segment is threadedly connected with the threaded sleeve.

[0017] Further, the second grouting hole has an end with a size greater than the diameter of the anchor rod.

[0018] Further, the lengths of the first grouting holes in the same plane are arranged from short to long, and the plane is a plane perpendicular to the ground plane.

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

[0020] 1. The pier-shaped reinforcing body is in the form of a trapezoid with a short upper part and a long lower part, the lower part has a large reinforcing range, and the upper part has a small reinforcing range, which can effectively reduce the reinforcing range, make the reinforcing target clear, and the reinforcing range clear, thereby reducing the grouting amount, saving materials, and realizing low-carbon construction of the tunnel engineering; meanwhile, the pier-shaped reinforcing body has strong anti-slippage and anti-deformation capabilities, which can effectively enhance the ability to resist overall instability and damage of the fault broken rock mass, and the anchor rod is used for re-reinforcement to provide anchoring force, tightly connect the tunnel surrounding rock and the pier-shaped reinforcing body into a whole, effectively limit the deformation and displacement of the surrounding rock, and improve the overall stability of the tunnel structure.

[0021] 2. The anchor rod pad is arranged on the anchor rod, the axial tension of the anchor rod can be dispersed to the tunnel face or the surface of the pier-shaped reinforcing body, and local crushing caused by stress concentration is avoided.

[0022] 3. The adjacent anchor rod pads are connected through the connecting rod and the screw rod, the anchor rod pads on the whole tunnel face are connected into a whole, thereby having a significant cooperative supporting effect, the overall rigidity is improved, and when the stress of a certain anchor rod is too large, the connecting piece can transmit part of the load to the adjacent anchor rod pad, and single-point stress concentration is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a whole structure schematic view of the tunnel face front fault broken zone reinforcing structure of the embodiment of the utility model;

[0024] Figure 2 It is a sectional structure schematic view of the tunnel face front fault broken zone reinforcing structure of the embodiment of the utility model.

[0025] Among them, the pier-shaped reinforcing body 1, the tunnel 11;

[0026] Anchoring rod segment 20, anchoring rod pad 21, fastening nut 22, connecting plate 23, screw rod 24, first threaded through hole 25, threaded sleeve 26. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application will now be described in detail below. It should be noted that the embodiments described herein are only used for illustration and do not limit the present application. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without necessarily adopting these specific details. In other instances, well-known circuits, software or methods have not been specifically described in order to avoid obscuring the present application.

[0028] Throughout this specification, the use of "one embodiment", "an embodiment", "one example", or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. Therefore, the appearance of the phrases "in one embodiment", "in an embodiment", "one example", or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner and / or sub-combination in one or more embodiments or examples. In addition, it should be understood by those skilled in the art that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0029] Please refer to Figures 1-2The utility model provides a kind of tunnel face of tunnel ahead of fault fracture zone reinforcing structure's embodiment, comprising: pier reinforcing body 1, first grouting hole being matrix distribution is set up on the face of tunnel ahead of fault fracture zone, first grouting hole grouting is to form pier reinforcing body 1, the end of pier reinforcing body 1 along the direction of excavation is inclined and with the direction of excavation is acute angle;Anchor rod, multiple second grouting holes are set up on pier reinforcing body 1, every second grouting hole is in-depth to hard rock zone along the direction of excavation of tunnel, and anchor rod is fixedly installed in second grouting hole by grouting.Use, grout is injected into first grouting hole, grout can be selected according to actual situation, and cement grout can be selected, and the side edge of every column first grouting hole forms a trapezoid of upper short lower long, so that after grouting solidification, pier reinforcing body 1 of the trapezoid of upper short lower long can be obtained, to provide support force directly to face, and its side is the trapezoid of upper short lower long design, can better adapt to the distribution characteristics of surrounding rock pressure in tunnel excavation process, improve the overall stability of structure, effectively prevent the collapse, chunk, etc. of face due to surrounding rock pressure, guarantee the safety of tunnel excavation working face.Then anchor rod is inserted into newly opened second grouting hole, and cement grout is injected into second grouting hole to fix anchor rod, so that under the condition of being preliminarily fixed by pier reinforcing body 1, anchor rod that extends into hard rock zone is used to provide anchoring force to pier reinforcing body 1, and tunnel surrounding rock and pier reinforcing body 1 are closely connected into a whole, effectively limit the deformation and displacement of surrounding rock, improve the overall stability of tunnel structure.The construction technology of entire reinforcing structure is relatively simple, and does not need complex formwork erection and large-scale mechanical equipment.Construction personnel can flexibly adjust the position and quantity of first grouting hole according to actual situation to adapt to different geological conditions and engineering requirements.

[0030] In the embodiment, the lengths of the first grouting holes in the same plane are set from short to long, and the first grouting holes at the higher positions are shorter than the first grouting holes at the lower positions. The plane is a plane perpendicular to the ground. After grouting is performed in the first grouting holes and solidification, a pier reinforcing body 1 in the form of a trapezoid of upper short lower long is formed.

[0031] The reinforcing purpose of the entire reinforcing structure is clear. The pier reinforcing body is in the form of a trapezoid of upper short lower long. The reinforcing range of the lower part is large, and the reinforcing range of the upper part is small. First, the reinforcing range can be effectively reduced, the reinforcing target is clear, the reinforcing range is clear, the amount of grouting is reduced, materials are saved, and low-carbon construction of the tunnel project is realized. Second, the pier reinforcing body itself has strong anti-slippage and anti-deformation capabilities, which can effectively enhance the ability to resist overall instability and damage of the fault fractured rock mass.

[0032] Figure 2 As shown in FIG. 11, the top and bottom of the pier reinforcing body 1 abut against the top and bottom of the tunnel 11, so that there is no gap between the pier reinforcing body 1 and the tunnel 11 in the vertical plane, and a better supporting effect is achieved.

[0033] In the embodiment, the end of the anchor rod close to the working face is detachably connected with an anchor rod pad plate 21, and one side of the anchor rod pad plate 21 abuts against the working face. In use, the anchor rod is first inserted into the second grouting hole, then the anchor rod is grouted and fixed, and finally the anchor rod pad plate 21 is installed on the anchor rod and abuts against the working face. The anchor rod pad plate 21 can disperse the axial tensile force of the anchor rod to the working face or the surface of the pier-shaped reinforcing body 1, so as to avoid stress concentration and local crushing. In addition, when the surrounding rock deforms, the friction force between the anchor rod pad plate 21 and the pier-shaped reinforcing body 1 can resist part of the shear displacement, so as to improve the shear resistance of the supporting system.

[0034] In the embodiment, the anchor rod pad plate 21 is sleeved on the anchor rod, the anchor rod is threadedly connected with a fastening nut 22, and the anchor rod pad plate 21 abuts between the working face and the fastening nut 22. After grouting is completed, the anchor rod pad plate 21 is fixed on the anchor rod through the fastening nut 22, and the flexibility and adaptability of construction are improved.

[0035] In the embodiment, the adjacent anchor rod pad plates 21 are detachably connected through connecting pieces. In use, all the anchor rod pad plates 21 on the working face are connected into a whole, which has a significant cooperative supporting effect, so that the overall rigidity is improved. When the stress of a certain anchor rod is too large, the connecting pieces can transfer part of the load to the adjacent anchor rod pad plates 21, so as to avoid single-point stress concentration. In addition, the overall connected anchor rod pad plates 21 can form a “pressure arch” effect, which disperses the surrounding rock pressure of the working face to the surrounding supporting system, so as to reduce the risk of local collapse. At the same time, by additionally arranging a tie anchor in the lower region of the pier-shaped reinforcing body, the sliding load is shared to the deep hard surrounding rock, so as to further improve the anti-sliding and anti-deformation ability of the reinforcing body, and effectively reduce the construction risk of the tunnel passing through the fault fracture.

[0036] In this embodiment, the connecting piece includes a connecting plate 23 and a screw rod 24, the anchor rod base plate 21 is provided with a first threaded hole 25, the connecting plate 23 is provided with a second threaded hole at both ends, the connecting plate 23 is arranged on the adjacent two anchor rod base plates 21, and the two second threaded holes are respectively aligned with the adjacent two first threaded holes 25; the screw rod 24 is threadedly connected in the second threaded hole and the corresponding first threaded hole 25. When the anchor rod base plate 21 is installed, the connecting plate 23 is placed on the adjacent two anchor rod base plates 21, the corresponding first threaded hole 25 and the second threaded hole are aligned, and finally the connecting plate 23 is locked on the adjacent two anchor rod base plates 21 through the screw rod 24, so as to achieve the effect of fixing and connecting the anchor rod base plates 21, effectively enhance the integrity and stability of the whole anchor rod support system, and better bear external load. For example, when subjected to external force, the load can be uniformly transmitted to the adjacent anchor rod through the connecting plate 23 and the screw rod 24, avoiding the occurrence of stress concentration phenomenon, thereby reducing the risk of damage to the support structure caused by uneven local stress. At the same time, the connecting mode of threaded connection makes the operation simple and convenient, and facilitates disassembly and replacement. In actual use, the length of the connecting plate 23 can be designed and adjusted according to the distance between the adjacent anchor rods, so as to adapt to the arrangement of anchor rods and anchor rod base plates 21 with different distances. In actual use, lock nuts can be threadedly connected at both ends of the screw rod 24 to prevent the screw rod 24 from loosening, so that the connection between the adjacent two anchor rod base plates 21 is more firm.

[0037] In this embodiment, the anchor rod is provided as a sectional anchor rod, the sectional anchor rod includes a plurality of anchor rod segments 20, and the adjacent anchor rod segments 20 are detachably connected. In use, the sectional anchor rod can be quickly assembled into a suitable length according to the site conditions, has strong flexibility, and increases the adaptability of the anchor rod. In addition, the sectional anchor rod is also suitable for storage and transportation.

[0038] In this embodiment, one end of each adjacent anchor rod segment 20 is fixedly connected with a threaded sleeve 26, and the threaded sleeve 26 is threadedly connected with one end of the adjacent anchor rod segment 20. In use, the threaded sleeve 26 is used to fixedly connect the adjacent two anchor rod segments 20 together, so as to ensure firm splicing. In actual use, the threaded sleeve 26 can be made of high-strength alloy steel (such as 42CrMo), and the shear strength is ≥120% of the anchor rod axial force, so as to ensure that the stress is transmitted without loss at the splicing position. In actual use, one end of each anchor rod segment 20 is provided with an external thread, and the other end of the anchor rod segment 20 is fixedly connected with a threaded sleeve 26 with a matching internal thread, so as to facilitate the connection between the two anchor rod segments 20.

[0039] In the embodiment, the end size of the second grouting hole is larger than the diameter size of the anchor rod. When grouting, the slurry can sufficiently fill the gap between the anchor rod and the hole wall, especially forming a larger slurry package at the end of the hole. And this package can provide a larger anchoring area after solidification, like a larger "grip" holding 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.

[0040] The specific use method of the embodiment is as follows:

[0041] In use, the cement slurry is poured into the first grouting hole, and the side edges of each column of first grouting holes form a short upper and long lower trapezoidal shape, so that a short upper and long lower trapezoidal pier-shaped reinforcing body 1 can be obtained after the grouting solidifies; then, according to the continued needs, the anchor rod segments 20 are connected into an anchor rod of the required length, and then the anchor rod is inserted into the newly opened second grouting hole, and the cement slurry is poured into the second grouting hole to fix the anchor rod.

[0042] After the anchor rod is fixed, the anchor rod pad 21 is installed on the anchor rod, and the anchor rod pad 21 is locked on the anchor rod by using the fastening nut 22; when all the anchor rod pads 21 are installed, the connecting plate 23 is placed on the adjacent two anchor rod pads 21, and the corresponding first threaded through hole 25 and the second threaded through hole are aligned, and finally the connecting plate 23 is locked on the adjacent two anchor rod pads 21 by the screw rod 24, until all the anchor rod pads 21 are connected into one body.

[0043] In summary, the pier-shaped reinforcing body is in the form of a short upper and long lower trapezoidal shape, the lower reinforcing range is large, and the upper reinforcing range is small, which can effectively reduce the reinforcing range, make the reinforcing target clear, and the reinforcing range clear, thereby reducing the grouting amount, saving materials, and realizing low-carbon construction of tunnel engineering; at the same time, the pier-shaped reinforcing body 1 has strong anti-slippage and anti-deformation ability, which can effectively enhance the ability to resist overall instability and damage of the fault broken rock mass, and the anchor rod is used for re-reinforcement to provide anchoring force, tightly connect the tunnel surrounding rock and the pier-shaped reinforcing body into one body, effectively limit the deformation and displacement of the surrounding rock, and improve the overall stability of the tunnel structure. Therefore, the utility model effectively overcomes the various shortcomings in the prior art.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, but not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model, and they should be covered in the scope of the claims and the specification of the utility model.

Claims

1. A structure for reinforcing a fault fracture zone in front of a tunnel face, characterized by, include: The pier-shaped reinforcement body has a first grouting hole distributed in a matrix on the face in front of the fault fracture zone. Grouting is performed in the first grouting hole to form the pier-shaped reinforcement body. One end of the pier-shaped reinforcement body along the tunneling direction is inclined and forms an acute angle with the tunneling direction. The anchor bolt has multiple second grouting holes on the pier-shaped reinforcement body. Each second grouting hole extends into the hard rock stratum along the tunnel excavation direction. The anchor bolt is fixedly installed in the second grouting hole by grouting.

2. The tunnel face ahead fault fracture zone reinforcement structure according to claim 1, characterized by: An anchor rod pad is detachably connected to one end of the anchor rod near the working face, and one side of the anchor rod pad abuts against the working face.

3. The tunnel face ahead fault fracture zone reinforcement structure according to claim 2, characterized in that: The anchor pad is fitted onto the anchor bolt, and a fastening nut is threaded onto the anchor bolt. The anchor pad abuts against the working face and the fastening nut.

4. The tunnel face ahead fault fracture zone reinforcement structure according to claim 2, characterized by: The adjacent anchor plates are detachably connected by connectors.

5. The tunnel face ahead fault fracture zone reinforcement structure according to claim 4, characterized in that: The connector includes a connecting plate and a screw. The anchor pad has a first threaded through hole, and the two ends of the connecting plate have symmetrical second threaded through holes. The connecting plate is disposed on two adjacent anchor pads, and the two second threaded through holes are respectively aligned with the two adjacent first threaded through holes. The screw is internally threaded into the second threaded through hole and the corresponding first threaded through hole.

6. The tunnel face ahead fault fracture zone reinforcement structure according to claim 1, characterized by: The anchor bolt is configured as a segmented anchor bolt, which includes multiple anchor bolt segments, and adjacent anchor bolt segments are detachably connected.

7. The tunnel face ahead fault fracture zone reinforcement structure according to claim 6, 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.

8. The tunnel face ahead fault fracture zone reinforcement structure according to claim 1, characterized by: The end dimension of the second grouting hole is larger than the diameter dimension of the anchor rod.

9. The tunnel face ahead fault fracture zone reinforcement structure as claimed in claim 1, characterized by: The lengths of the first grouting holes on the same plane are set from shortest to longest, and the plane is a plane perpendicular to the ground plane.

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