A device for adjusting the pressure relief arch foot of a steel arch frame under large deformation conditions of tunnel surrounding rock

Abstract

The present application discloses a pressure relief arch foot adjustment device for a steel arch frame under conditions of large deformation of the surrounding rock of a tunnel. In this scheme, firstly, the pressure of the arch frame on the bottom of the tunnel is further reduced by the steel bottom plate, thereby reducing the degree of damage to the rock mass at the bottom of the tunnel. At the same time, the arch foot of the steel arch frame is made absolutely vertical to the ground by the arch foot limiting device of the steel arch frame. The pressure relief arch foot adjustment device of the steel arch frame is fixed by steel nails and anchor rods, and the moment of inertia of the arch frame itself is continuous. The above features jointly ensure the safety and stability of the arch foot of the steel arch frame. Secondly, the pressure relief arch foot device of the steel arch frame is located at the bottom of the side wall of the tunnel, which is convenient for observing the instant pressure relief amount, and the pressure relief stiffness and pressure relief range of the subsequent pressure relief device can be determined based on this. Furthermore, by changing the number and specifications of the "Z"-shaped pressure relief steel plates, the pressure relief function of the steel arch frame can be realized without affecting the overall structure of the steel arch frame. The overall device has the advantages of strong visibility, simple operation, flexible setting, stability and safety.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel construction, and in particular to a steel arch frame pressure relief arch foot adjustment device for use under conditions of large deformation of tunnel surrounding rock. Background Art

[0002] With the vigorous development of transportation construction and water conservancy development in western my country, the number of tunnels passing through areas prone to large deformation such as high-altitude stress soft rock has gradually increased. During the construction process, the large deformation of the surrounding rock of the tunnel section in areas prone to large deformation such as soft rock has the characteristics of accumulation in the time dimension, and the deformation is often relatively large. The deformation of the surrounding rock presents the characteristics of dynamic continuous and gradually accumulated changes. In view of the above-mentioned surrounding rock deformation characteristics, the use of traditional rigid arch frame structure for support often bears a large surrounding rock deformation pressure. If it exceeds the bearing limit of the steel arch frame, it will face serious construction safety problems. Practice has shown that simply improving the support strength is still not enough to control the surrounding rock deformation. Therefore, it is necessary to release the surrounding rock deformation. Under the premise of not significantly affecting the strength of the steel arch frame structure, it is necessary to enable it to have a certain pressure-releasing function to absorb the energy accumulated in the surrounding rock and release it to the outside world, thereby reducing the pressure of the steel arch frame arch body and providing a constant resistance for the stable deformation of the surrounding rock mass. This is not only conducive to extending the life of the support structure, but also beneficial to the long-term stability of the water transfer tunnel.

[0003] However, the inventors have found that the inventions involving the pressure-releasing devices of steel arch frames in the past are all located at the segmented connections of the steel arch frames, and their installation is relatively complicated and difficult to operate, and it is difficult to adjust the stiffness and pressure-releasing range of the pressure-releasing devices. At the same time, the steel arch frames with pressure-releasing devices installed at the segmented connections are affected by their own moment of inertia discontinuity or docking accuracy, causing the axial force of the arch frames to deviate from the plane where the arch frames themselves are located, which may easily lead to the instability of the pressure-releasing devices at the segmented connections or the instability of the arch feet caused by the inclination of the arch feet. At this time, the absolute verticality of the arch feet to the ground is very important. At the same time, when the pressure-releasing device is located at the arch frame connection, it is difficult to monitor the instantaneous pressure-releasing amount of the arch frame to guide the determination of the pressure-releasing stiffness and pressure-releasing range of the subsequent pressure-releasing device. Summary of the invention

[0004] In view of this, the present application provides a steel arch frame pressure-releasing arch foot adjustment device for use under large deformation conditions of tunnel surrounding rock, which can ensure the continuity of the steel arch frame stiffness and the stability of the steel arch frame arch foot, while realizing the observable and adjustable pressure-releasing function of the steel arch frame arch foot.

[0005] The present application provides a steel arch frame pressure relief arch foot adjustment device for use under large deformation conditions of tunnel surrounding rock, characterized in that it comprises a steel bottom plate, a steel vertical plate, an anchor rod, a "Z"-shaped pressure relief steel plate, an "L"-shaped steel plate, and a steel arch frame arch foot limiting device; the surface of the steel bottom plate away from the tunnel wall is provided with steel nails for inserting into the tunnel ground, the steel vertical plate is in contact with the tunnel side wall, the steel vertical plate is perpendicular to the steel bottom plate, the steel vertical plate is provided with holes, the holes are used for fixing the first end of the anchor rod, and the second end of the anchor rod is used for inserting into the tunnel side wall, the "L"-shaped steel plate is vertically connected to the steel bottom plate, and one vertical side of the "L"-shaped steel plate is vertically connected to the steel vertical plate, the two "L"-shaped steel plates are arranged at intervals, the "Z"-shaped pressure relief steel plate is located between the cavity formed by the "L"-shaped steel plate and the vertical steel plate, and the steel arch frame arch foot limiting device is located between the cavity formed by the "L"-shaped steel plate and the vertical steel plate and located above the pressure relief "Z"-shaped steel plate.

[0006] Optionally, the horizontal area of ​​the steel bottom plate is larger than the area enclosed by the “L”-shaped steel plate and the vertical steel plate.

[0007] Optionally, the steel vertical plate and the steel bottom plate have the same thickness and the same length of their connecting edges, and the hole positions are symmetrically distributed about the vertical axis of the steel vertical plate.

[0008] Optionally, the first end of the anchor rod is inserted and fixed in the hole by means of a nut and a gasket.

[0009] Optionally, the inner diameter of the gasket is the same as the inner diameter of the hole, the outer diameter of the gasket is larger than the outer diameter of the nut, the internal thread of the nut matches the external thread of the first end of the anchor rod, and the diameter of the anchor rod is smaller than the inner diameter of the hole.

[0010] Optionally, the thickness of the "L"-shaped steel plate is the same as that of the steel base plate, and an observation groove is formed between the two "L"-shaped steel plates, with scales engraved on both sides of the groove.

[0011] Optionally, when multiple "Z"-shaped pressed steel plates have different thicknesses, the thicker one is located at the bottom.

[0012] Optionally, the "Z" shape allows the area of ​​the oblique side of the pressed steel plate to be smaller than the bottom surface of the rectangular area enclosed by the "L"-shaped steel plate and the steel vertical plate.

[0013] Optionally, the steel arch frame arch foot limiting device includes a limiting base plate, a rectangular steel cylinder, side wings, and protrusions. The rectangular steel cylinder and the steel base plate have the same center and are vertically connected. One side of each side wing is fixed to a corner of the rectangular steel cylinder, and the other side of each side wing extends to the inner wall of the "L"-shaped steel plate. The horizontal projection area of ​​the limiting base plate is smaller than the bottom area of ​​the rectangular area surrounded by the "L"-shaped steel plate and the steel vertical plate but larger than the horizontal projection area of ​​the "Z"-shaped pressure relief steel plate. The protrusions correspond to observation slots to facilitate subsequent instant observation of the pressure relief amount.

[0014] Optionally, the gap between the steel arch frame arch foot limiting device and the "L"-shaped steel plate is filled with foam filler.

[0015] Optionally, the portion of the space enclosed by the "L"-shaped steel plate, the limiting bottom plate and the steel bottom plate that is not the "Z"-shaped pressure steel plate is filled with foam filler.

[0016] Compared with the prior art, this application has the following beneficial effects:

[0017] 1. The steel bottom plate is used to further reduce the pressure of the arch frame on the bottom of the tunnel, and the degree of damage to the rock mass at the bottom of the tunnel is reduced. At the same time, the arch foot of the steel arch frame is made absolutely vertical to the ground through the arch foot limiter of the steel arch frame. The steel arch frame is fixed by steel nails and anchor rods to allow the arch foot adjustment device to be pressed, and the arch frame's own moment of inertia is continuous. The above features jointly ensure the safety and stability of the arch foot of the steel arch frame.

[0018] 2. The arch foot device of the steel arch frame is located at the bottom of the tunnel side wall, which is convenient for observing the real-time pressure relief amount, and the pressure relief stiffness and pressure relief range of the subsequent pressure relief device can be determined based on this.

[0019] 3. By changing the number and specifications of the "Z"-shaped pressure-relieving steel plates, the pressure-relieving function of the steel arch frame can be realized without affecting the overall structure of the steel arch frame. Because it is an additional device at the end of the steel arch frame, it is easy to install. The device as a whole has the advantages of strong visibility, simple operation, flexible setting, stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0021] Figure 1 A schematic diagram of the cross-sectional structure of a tunnel provided in an embodiment of the present application.

[0022] Figure 2 A schematic diagram of a three-dimensional structure provided in an embodiment of the present application.

[0023] Figure 3 for Figure 2 Schematic diagram of the three-dimensional structure in the decomposed state.

[0024] Figure 4 for Figure 2 Structural cross-section view.

[0025] The components in the figure are marked as follows:

[0026] 1-fixed and limited base; 11-steel bottom plate; 12-steel nails; 13-steel vertical plate; 14-hole position; 15-"L" type steel plate; 16-observation groove; 2-anchor rod; 3-pad; 4-nut; 5-"Z" type pressure steel plate; 6-steel arch foot limit device; 61-limited bottom plate; 62-rectangular steel cylinder; 63-side wing; 64-convex point; 7-steel arch frame; 8-foam sealant. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0028] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0031] Please refer to Figure 1-Figure 4The embodiment of the present application is used for adjusting the arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel, including a fixed and limited base 1, a friction-type steel anchor rod 2 which uses a hexagonal nut 4 to constrain the fixed and limited base 1 at the foot of the tunnel through a circular steel gasket 3, a "Z"-shaped pressure-releasing steel 5 is placed in the fixed and limited base 1, a steel arch foot limiting device 6 is located on the "Z"-shaped pressure-releasing steel 5, a steel arch frame 7 is inserted into the steel arch foot limiting device 6, and a foam sealant 8 is filled in the cavity of the "Z"-shaped pressure-releasing steel 5.

[0032] The horizontal steel bottom plate 11 is in contact with the bottom of the tunnel. The steel bottom plate has enough area to share the axial force transmitted by the steel arch frame and reduce the degree of damage to the rock mass at the bottom of the tunnel. At the same time, the thickness and strength of the steel bottom plate 11 can ensure the overall stability of the pressure arch foot adjustment device of the steel arch frame. There are two steel nails 12 on the side of the bottom plate away from the tunnel wall. The steel nails 12 are to be inserted into the holes drilled in advance on the tunnel ground. The steel vertical plate 13 is in contact with the side wall of the tunnel. The steel vertical plate 13 is perpendicular to the steel bottom plate 11. There is one at each of the four corners of the steel vertical plate 13. There are two hole positions 14, and "L"-shaped steel plates 15, both of which are vertically connected to the steel bottom plate 11, and one vertical side of the "L"-shaped steel plate 15 is vertically connected to the steel vertical plate 13. The thickness of the "L"-shaped steel plate 15 is the same as that of the steel bottom plate 11. The "L"-shaped steel plate 15 and the steel vertical plate 13 together form a rectangular area. There is a gap between the two "L"-shaped steel plates 15, and the gap forms an observation groove 16 for observing the pressure release amount. The scales on both sides of the observation groove 16 can be used to instantly observe the pressure release amount of the pressure release device.

[0033] The thickness of the steel vertical plate 13 is the same as that of the steel bottom plate 11 and the length of the connecting edges thereof is the same. There is a circular hole 14 at each of the four corners of the steel vertical plate 13. Each hole 14 is at a distance from the edge of the steel vertical plate 13 to improve the shear strength of the hole 14. The holes 14 are symmetrically distributed about the vertical axis of the steel vertical plate 13. There are four anchor rods 2 in total. The first end of the anchor rod 2 has a hexagonal nut 4 which is transitionally fixed to the hole 14 of the steel vertical plate 13 through a circular gasket 3. The second end of the anchor rod 2 is inserted into the rock mass at a certain angle to the side wall of the tunnel. The steel nail 12 and the anchor rod 2 together form a fixing effect on the fixed and limited base 1, thereby limiting the displacement of the fixed and limited base 1 and ensuring that the fixed and limited base 1 is absolutely level.

[0034] The inner diameter of the gasket 3 is the same as the inner diameter of the hole 14 of the steel vertical plate, the outer diameter of the gasket 3 is larger than the outer diameter of the hexagonal nut 4, the internal thread of the nut 4 matches the external thread of the first end of the anchor rod 2, and the pipe diameter of the anchor rod 2 is smaller than the inner diameter of the hole 14 of the steel vertical plate 13.

[0035] The "Z"-shaped pressure steel plate 5 is located within the fixed and limited base 1. There is one or more "Z"-shaped pressure steel plates 5, and their height is constant at about 10 cm, but the thickness of the steel plate has a variety of sizes (such as 8 mm, 10 mm, 12 mm). When the thickness of multiple "Z"-shaped pressure steel plates 5 is different, the thicker one is located at the bottom, such as Figure 4 As shown, the area of ​​the inclined surface of the "Z"-shaped pressing steel plate 5 is smaller than the bottom surface of the rectangular area surrounded by the "L"-shaped steel plate 15 and the steel vertical plate 13.

[0036] The “Z”-shaped yielding steel plate 5 and the steel arch frame arch foot limiting device 6 are located in the rectangular area surrounded by the “L”-shaped steel plate 15 and the steel vertical plate 13 , and the “Z”-shaped yielding steel plate 5 is located above the steel bottom plate 11 and below the steel arch frame arch foot limiting device 6 .

[0037] The steel arch frame arch foot limit device 6 is composed of a limit base plate 61, a rectangular steel cylinder 62, four side wings 63, and a protrusion 64. The center of the rectangular steel cylinder 62 is the same as that of the limit base plate 61 and they are vertically connected. One side of each side wing 63 is fixed to a corner of the rectangular steel cylinder 62, and the other side of each side wing extends to the inner wall of the "L"-shaped steel plate 15. The protrusion 64 can extend into the observation groove 16 formed between the two "L"-shaped steel plates. The instantaneous pressure relief amount of the pressure relief device can be instantly obtained through the position of the protrusion 64 corresponding to the scale on the observation (measurement) groove.

[0038] The horizontal projection area of ​​the limiting bottom plate 61 of the limiting device for the arch foot of the steel arch frame is slightly smaller than the bottom area of ​​the rectangular area surrounded by the "L"-shaped steel plate 15 and the steel vertical plate 13 to ensure that the concrete entering the cavity of the "Z"-shaped pressure steel plate 5 is reduced as much as possible during the subsequent re-spraying of concrete. At the same time, the horizontal projection area of ​​the limiting bottom plate 61 of the limiting device for the arch foot of the steel arch frame is larger than the horizontal projection area of ​​the "Z"-shaped pressure steel plate 5.

[0039] After the steel arch foot limit device is installed, it is necessary to inject foam filler 8 through the gap 16 between the two "L"-shaped steel plates to fill the remaining space of the "Z"-shaped pressure-relieving steel plate 5 in the rectangular area surrounded by the "L"-shaped steel plate 15 and the steel vertical plate 13, so as to prevent concrete from entering between the "Z"-shaped pressure-relieving steel plates 5 during subsequent concrete spraying and affecting the normal use of the pressure-relieving device.

[0040] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A device for adjusting the arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel. It is characterized in that It includes a steel bottom plate, a steel vertical plate, an anchor rod, a "Z"-shaped pressure-relief steel plate, an "L"-shaped steel plate, and a steel arch foot limiting device; the surface of the steel bottom plate away from the tunnel wall is provided with a steel nail for inserting into the tunnel ground, the steel vertical plate is in contact with the tunnel side wall, the steel vertical plate is perpendicular to the steel bottom plate, a hole is opened in the steel vertical plate, the hole is used for fixing the first end of the anchor rod, and the second end of the anchor rod is used to insert into the tunnel side wall, the "L"-shaped steel plate is vertically connected to the steel bottom plate, and one vertical side of the "L"-shaped steel plate is vertically connected to the steel vertical plate, and the two "L"-shaped steel plates are arranged at intervals, the "Z"-shaped pressure-relief steel plate is located between the cavity formed by the "L"-shaped steel plate and the vertical steel plate, and the steel arch foot limiting device is located between the cavity formed by the "L"-shaped steel plate and the vertical steel plate and located above the pressure-relief "Z"-shaped steel plate; The initial working load of the upper "Z"-shaped yield steel plate is smaller than that of the lower "Z"-shaped yield steel plate, and the normal working load range of the "Z"-shaped yield steel plate is smaller than the yield load of the steel arch frame; The "Z" shape makes the area of ​​the oblique side of the pressed steel plate smaller than the bottom surface of the rectangular area surrounded by the "L"-shaped steel plate and the steel vertical plate; The said steel arch frame arch foot limiting device comprises a limiting bottom plate, a rectangular steel cylinder, and side wings. The rectangular steel cylinder and the steel bottom plate have the same center and are vertically connected. One side of each side wing is fixed to a corner of the rectangular steel cylinder, and the other side of each side wing extends to the inner wall of the "L"-shaped steel plate. The horizontal projection area of ​​the said limiting bottom plate is smaller than the bottom area of ​​the rectangular parallelepiped area surrounded by the "L"-shaped steel plate and the steel vertical plate, but larger than the horizontal projection area of ​​the "Z"-shaped yield steel plate. The part of the space surrounded by the "L"-shaped steel plate, the limiting bottom plate and the steel bottom plate which is not a "Z"-shaped pressing steel plate is filled with foam filler.

2. According to claim 1, the device for adjusting the pressure relief arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel, It is characterized in that The horizontal area of ​​the steel bottom plate is larger than the area enclosed by the "L"-shaped steel plate and the vertical steel plate.

3. According to claim 1, the device for adjusting the arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel, It is characterized in that The thickness of the steel vertical plate is the same as that of the steel bottom plate and the length of the connecting edges thereof is the same, and the hole positions are symmetrically distributed about the vertical axis of the steel vertical plate.

4. According to claim 1, the device for adjusting the pressure relief arch foot of a steel arch frame used under conditions of large deformation of the surrounding rock of a tunnel, It is characterized in that The first end of the anchor rod is inserted and fixed in the hole through a nut and a gasket.

5. According to claim 4, the device for adjusting the arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel, It is characterized in that The inner diameter of the gasket is the same as the inner diameter of the hole, the outer diameter of the gasket is larger than the outer diameter of the nut, the inner thread of the nut matches the outer thread of the first end of the anchor rod, and the diameter of the anchor rod is smaller than the inner diameter of the hole.

6. The device for adjusting the arch foot of a steel arch frame under large deformation conditions of the surrounding rock of a tunnel according to claim 4, It is characterized in that The thickness of the "L"-shaped steel plate is the same as that of the steel base plate. An observation groove is formed between the two "L"-shaped steel plates, and scales are engraved on both sides of the groove.

7. The device for adjusting the arch foot of a steel arch frame under large deformation conditions of surrounding rock in a tunnel according to claim 1, It is characterized in that Multiple "Z" shapes allow the pressed steel plates to have different thicknesses, with the thicker ones located at the bottom.

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