Active load-bearing system and method for tunnel locking steel pipe

Abstract

An active bearing system for a tunnel locking foot steel pipe includes a reaction ring arranged just above the locking foot steel pipe and fixed on the I-beam, a pressure device in contact with the locking foot steel pipe, and a pushing mechanism that applies downward force to the pressure device, thereby pushing the locking foot steel pipe downward, wherein one end of the pushing mechanism is hinged on the reaction ring, and the other end is hinged on the pressure device. An active bearing method for a tunnel locking foot steel pipe includes supporting an arc-shaped pressure plate of the pressure device on the locking foot steel pipe, starting the telescopic structure of the pushing mechanism, and pushing the arc-shaped pressure plate downward through the force-transmitting steel pipe to cause the locking foot steel pipe to bend downward, so that the I-beam obtains a corresponding supporting force, and then the telescopic structure contracts accordingly as the surrounding rock and the I-beam sink downward. The system and method provided by the present invention can realize active bearing of the locking foot steel pipe, and the locking foot steel pipe will not fail due to excessive deformation. The installation is convenient, the material consumption is small, and the cost is low.

Description

Technical Field

[0001] The invention relates to the field of tunnels and underground engineering, and in particular to an active bearing system and method for a tunnel foot locking steel pipe. Background Art

[0002] The locking foot steel pipe is an important method for controlling the settlement of the initial support structure of the tunnel. The locking foot steel pipe usually adopts a seamless steel pipe with a diameter of 42mm to 108mm. The outer end is welded to the I-beam of the initial support, and the inner end is inserted into the rock and soil. When the initial support I-beam settles downward, the outer end of the steel pipe inserted into the rock and soil also moves downward synchronously, causing the steel pipe to bend and provide upward support. According to the traditional construction method, the locking foot steel pipe is directly welded to the steel arch frame after being driven in. Only when the I-beam settles, the locking foot steel pipe will deform and exert its bearing capacity. Only when the I-beam settles greatly, the locking foot steel pipe can provide a larger bearing capacity. Therefore, the locking foot steel pipe is a passive bearing mode. The large settlement of the I-beam often means that the tunnel surrounding rock is greatly deformed or even destroyed, which is very unfavorable to the stability of the tunnel surrounding rock and support structure. Therefore, for tunnels that are prone to large deformation, it is very necessary to make the locking foot steel pipe actively provide bearing capacity, and provide support force to control the deformation when the I-beam and surrounding rock do not undergo settlement deformation. Summary of the invention

[0003] Aiming at the problem that the passive bearing of the locking foot steel pipe in the tunnel leads to the inability to provide supporting force as soon as possible, which is not conducive to controlling the settlement of I-beams and surrounding rocks, the present invention provides an active bearing system and method for locking foot steel pipes, which actively bends the locking foot steel pipes by providing reaction force through I-beams, thereby immediately providing supporting force.

[0004] The present invention includes the following embodiments:

[0005] An active bearing system for a tunnel locking foot steel pipe comprises a reaction ring arranged directly above the locking foot steel pipe and fixed on an I-beam, a pressure device in contact with the locking foot steel pipe, and a pushing mechanism which applies a downward force to the pressure device, thereby pushing the locking foot steel pipe downward, wherein one end of the pushing mechanism is hinged on the reaction ring, and the other end is hinged to the pressure device.

[0006] When this embodiment is in use, the arc-shaped pressure plate of the pressure device is wrapped around the end of the locking foot steel pipe, the telescopic structure of the pushing mechanism is started, and the arc-shaped pressure plate is pushed downward by the force-transmitting steel pipe to cause the locking foot steel pipe to bend downward, thereby controlling the supporting force on the I-beam, thereby controlling the deformation of the surrounding rock. Compared with traditional construction methods, the present invention consumes less materials and has low cost, so that the locking foot steel pipe can provide bearing capacity after installation.

[0007] In this embodiment, the reaction ring is a reaction steel plate with a central circular hole.

[0008] In this embodiment, the pushing mechanism includes a telescopic structure and an upper connecting member and a lower connecting member fixedly connected to the upper and lower ends of the telescopic structure respectively.

[0009] In this embodiment, the telescopic structure is a mechanical, electric or hydraulic push rod.

[0010] In this embodiment, the pressure device includes a force transmission steel plate with a central circular hole and an arc-shaped pressure plate. The arc-shaped pressure plate is fixed at the bottom of the force transmission steel plate. The arc-shaped pressure plate is provided with an arc-shaped positioning groove matching the outer diameter of the locking foot steel tube on the side facing the locking foot steel tube.

[0011] In this embodiment, the upper connecting member of the pushing mechanism is rotatably connected to the reaction ring via a rotating shaft, and the lower connecting member is rotatably connected to the force transmission steel plate via a rotating shaft.

[0012] A tunnel locking foot steel pipe active bearing method, using the above-mentioned tunnel locking foot steel pipe active bearing system, supporting the arc-shaped pressure plate of the pressure device on the locking foot steel pipe, starting the telescopic structure of the jacking mechanism, pushing the arc-shaped pressure plate downward through the force transmission steel pipe, causing the locking foot steel pipe to bend downward, so that the I-beam obtains corresponding supporting force, and then as the surrounding rock and the I-beam sink downward, the telescopic structure contracts accordingly.

[0013] To sum up, the present invention uses the jacking mechanism to make the locking foot steel pipe deform appropriately before the I-beam and surrounding rock settle, actively provides supporting force for the I-beam, which is beneficial to suppress the deformation and loosening of the surrounding rock, and realizes dynamic adaptation between the settlement of the I-beam and the deformation of the locking foot steel pipe through the stroke of the jacking mechanism. The deformation and bearing capacity of the locking foot steel pipe can be dynamically adjusted, and it will not fail due to excessive settlement of the I-beam. The present invention has small installation workload, convenient operation, low material consumption and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of an active load-bearing system of a tunnel locking steel pipe according to the present invention.

[0015] Figure 2 It is a front view and a side view of the reaction ring of the present invention.

[0016] Figure 3 It is a front view and a side view of the pushing mechanism of the present invention.

[0017] Figure 4 It is a front view and a side view of the pressure applying device of the present invention.

[0018] In the figure: 1-locking foot steel pipe; 11-deformed locking foot steel pipe; 2-reaction ring; 3-pushing mechanism; 4-pressure device; 5-surrounding rock; 6-I-beam; 21-center circular hole; 22-reaction steel plate; 31-upper connecting piece; 32-lower connecting piece; 33-telescopic structure; 41-force transmission steel plate; 42-arc pressure plate. DETAILED DESCRIPTION

[0019] In order to better understand the present invention, the invention is further described in detail below in conjunction with the accompanying drawings and implementation examples, but the implementation methods of the present invention are not limited thereto. The protection scope of the present invention also involves equivalent technical means that can be thought of by those skilled in the art based on the concept of the present invention.

[0020] See also Figure 1 to Figure 4 , an active load-bearing system for a tunnel locking foot steel pipe, comprising a locking foot steel pipe 1, a reaction ring 2, a push mechanism 3 and a pressure device 4. The reaction ring 2 is a reaction steel plate 22 with a central circular hole 21, and the thickness of the reaction steel plate 22 meets the load-bearing requirements. The push mechanism 3 comprises a telescopic structure 33 and an upper connecting member 31 and a lower connecting member 32 respectively fixedly connected to one end of the telescopic structure 33. The telescopic structure can be a mechanical, electric or hydraulic push rod, and the present embodiment adopts a mechanical push rod. The pressure device 4 is welded by a force transmission steel plate 41 with a central circular hole and an arc-shaped pressure plate 42. The upper connecting member 31 of the push mechanism is rotatably connected to the reaction ring 2 through a rotating shaft, and the lower connecting member 32 is rotatably connected to the force transmission steel plate 41 through a rotating shaft. The arc-shaped pressure plate 42 is provided with an arc-shaped positioning groove matching the outer diameter of the locking foot steel pipe 1 on the side facing the locking foot steel pipe 1, so as to achieve close transmission of pressure.

[0021] During tunnel construction, the I-beam 6 is installed after the surrounding rock 5 is excavated. When the surrounding rock 5 is relatively weak and has poor stability, the surrounding rock 5 and the I-beam 6 will undergo deformation such as sinking downwards, and in severe cases, they will collapse. At this time, the locking foot steel pipe 1 is required to provide support force. According to the traditional method, the locking foot steel pipe 1 is directly welded to the I-beam 6 after construction. Only when the I-beam 6 sinks downwards, the locking foot steel pipe 1 will be deformed synchronously and provide support force. The greater the deformation, the greater the support force. When the deformation exceeds a certain range, the locking foot steel pipe 1 will be damaged and fail. The present invention can control the support force in the following way:

[0022] A method for actively bearing the locking foot steel pipe in a tunnel, firstly, a reaction ring 2 is welded on an I-steel 6, and a locking foot steel pipe 1 is driven into the surrounding rock 5, and then a jacking mechanism 3 and a pressure device 4 are connected to the reaction ring 2, and the distance between the reaction ring 2 and the end of the locking foot steel pipe 1 is the minimum value of the jacking mechanism 3. The arc-shaped pressure plate 42 of the pressure device 4 is covered on the end of the locking foot steel pipe 1, and the telescopic structure 33 of the jacking mechanism 3 is started, and the arc-shaped pressure plate 42 is pushed downward by the force transmission steel pipe 41, so that the locking foot steel pipe 1 bends downward, and the deformed locking foot steel pipe 11 is formed. Thus, the corresponding supporting force can be obtained on the I-steel 6 to control the deformation of the surrounding rock 5. In the next step of construction, the surrounding rock 5 and the I-steel 6 will sink downward. If the telescopic structure 33 is not adjusted, the locking foot steel pipe 1 will continue to deform. At this time, according to the limit deformation capacity of the locking foot steel pipe 1, the telescopic structure 33 can be partially retracted to make the deformation of the locking foot steel pipe 1 within the allowable range, so as not to cause damage and failure. When the surrounding rock 5 and the I-beam 6 are stable, or the subsequent construction is completed, the locking foot steel pipe 1 is firmly welded to the I-beam 6, the telescopic structure 33 is retracted, and the jacking mechanism 3 and the pressure device 4 can be removed for subsequent full use. Compared with the traditional construction method, the material consumption added by the present invention is the reaction ring 2, the material consumption is small, and the cost is low.

[0023] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A tunnel locking steel pipe active load-bearing system, characterized in that: The invention comprises a reaction ring (2) arranged just above the locking foot steel tube (1) and fixed on the I-beam (6), a pressure device (4) in contact with the locking foot steel tube (1), and a pushing mechanism (3) for applying a downward force to the pressure device (4) to push the locking foot steel tube (1) downward, wherein one end of the pushing mechanism (3) is hinged on the reaction ring (2) and the other end is hinged on the pressure device (4), and the pushing mechanism (3) comprises a telescopic structure (33) and An upper connecting member (31) and a lower connecting member (32) are respectively fixedly connected to the upper and lower ends of the telescopic structure (33), and the pressure device (4) includes a force transmission steel plate (41) with a central circular hole (21) and an arc-shaped pressure plate (42), wherein the arc-shaped pressure plate (42) is fixed to the bottom of the force transmission steel plate (41), and the arc-shaped pressure plate (42) is provided with an arc-shaped positioning groove matching the outer diameter of the lock foot steel tube (1) on the side facing the lock foot steel tube (1); The arc-shaped pressure plate (42) of the pressure device (4) is supported on the locking foot steel pipe (1), and the telescopic structure (33) of the pushing mechanism (3) is started. The arc-shaped pressure plate (42) is pushed downward by the force transmission steel plate, so that the locking foot steel pipe (1) bends downward, so that the I-beam (6) obtains a corresponding supporting force, and then as the surrounding rock (5) and the I-beam (6) sink downward, the telescopic structure (33) contracts accordingly.

2. According to claim 1, the tunnel locking foot steel pipe active load-bearing system is characterized by: The reaction ring (2) is a reaction steel plate (22) with a central circular hole (21).

3. According to claim 2, the tunnel foot locking steel pipe active load-bearing system is characterized by: The telescopic structure (33) is a mechanical, electric or hydraulic push rod.

4. According to claim 2, the tunnel foot locking steel pipe active load bearing system is characterized by: The upper connecting member (31) of the pushing mechanism (3) is rotatably connected to the reaction ring (2) via a rotating shaft, and the lower connecting member (32) is rotatably connected to the force transmission steel plate (41) via a rotating shaft.

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