Steel arch support assembly, steel arch support system and its support control method

Abstract

The present invention discloses a steel arch support assembly for a circular-section tunnel, which includes an inner support and an outer support. The outer support is a split structure that is circumferentially divided into multiple segmented support bodies. An arc-shaped I-beam is provided between adjacent support bodies. A circumferential yielding component for controlling the distance between adjacent ends of the support bodies is provided between the adjacent ends of the adjacent support bodies and the arc-shaped I-beam. A radial yielding component for controlling the radius size of the outer support is provided between the inner support and the arc-shaped I-beam. The present invention also provides a steel arch support system and a support control method thereof. The steel arch support assembly, the steel arch support system and the support control method of the present invention can provide corresponding support forces according to the change of surrounding rock stress, and accurately control the local and overall yielding amounts.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel construction, and particularly relates to a steel arch support assembly and a support control method thereof. Background Art

[0002] During the excavation of a tunnel, the surrounding rock pressure pattern of the tunnel cross-section will be affected differently due to the difference in cross-sectional shape. For highway and railway tunnel projects, adopting a circular design is an extremely stable building structure form, which can effectively bear the huge pressure of the surrounding rock, ensure the stability of the tunnel, and prevent the occurrence of collapse accidents.

[0003] When dealing with the challenges brought by soft surrounding rock in a high in-situ stress environment, the yielding support technology of the circular steel arch support assembly shows its effectiveness. However, due to the rheological properties of the soft surrounding rock, this property becomes particularly significant under the influence of high in-situ stress. Specifically, even if the stress on the surrounding rock remains unchanged, its deformation will gradually increase over time. There are numerous cases where the steel arch support assembly is damaged due to excessive deformation. The current design of the steel arch support assembly cannot provide corresponding support force according to the change of the surrounding rock stress, nor can it accurately control the local and overall yielding degree. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies and defects in the background art, and provide a steel arch support assembly, a steel arch support system and a support control method thereof for a circular cross-section tunnel. The steel arch support assembly and the support control method can provide corresponding support force according to the change of the surrounding rock stress, and accurately control the local and overall yielding amount.

[0005] To solve the above technical problem, the technical solution proposed by the present invention is as follows:

[0006] A steel arch support assembly for a circular tunnel includes an inner support and an outer support. The outer support is a split structure that is circumferentially divided into multiple segmented frames. An arc-shaped I-beam is provided between adjacent segmented frames. A circumferential yielding component for controlling the distance between adjacent ends of the adjacent segmented frames is provided between the adjacent ends of the adjacent segmented frames and the arc-shaped I-beam. A radial yielding component for controlling the radius size of the outer support is provided between the inner support and the arc-shaped I-beam.

[0007] The arc-shaped I-beam includes an arc-shaped outer top surface (located outside the steel arch support assembly) and an arc-shaped inner bottom surface (located inside the steel arch support assembly). A vertical connecting plate is provided between the arc-shaped outer top surface and the arc-shaped inner bottom surface. The circumferential yielding component is arranged between the end of the sub-frame and the vertical connecting plate, and the radial yielding component is arranged between the inner support and the arc-shaped inner bottom surface. The arc-shaped I-beam has better matching with the steel arch support assembly with a circular cross-section. Specifically, from a mechanical perspective, after the arc-shaped I-beam is connected to the sub-frame, it can effectively transfer force and bear loads. The arc-shaped I-beam can provide bending and compressive resistance capabilities suitable for the sub-frame, and can jointly resist external forces such as surrounding rock pressure with the sub-frame to maintain the structural stability. In terms of structural matching, the arc-shaped structure of the arc-shaped I-beam fits well with the arc-shaped structure of the arc-shaped sub-frame, facilitating connection and forming an integral structure. By reasonably designing the connection nodes, the two can work well together after connection.

[0008] The circumferential yielding component includes an arc-shaped hydraulic cylinder, a guide rail, and a slider. The guide rail is arranged on the vertical connecting plate and is parallel to the vertical connecting plate (i.e., the setting direction of the guide rail points to the center of the steel arch support assembly). The slider is slidably arranged on the guide rail. One end of the arc-shaped hydraulic cylinder is arranged at the end of the sub-frame, and the other end is arranged on the slider. The guide rail provides precise guidance for the slider, enabling the slider to slide up and down along the guide rail. Coupled with the telescoping of the arc-shaped hydraulic cylinder, the distance between the ends of adjacent sub-frames can be controlled, and the radius of the outer support can be changed. Specifically, when it is necessary to reduce the radius of the outer support, the slider slides towards the center of the steel arch support assembly on the guide rail, and at the same time, the arc-shaped hydraulic cylinder contracts, reducing the distance between the end of the sub-frame and the vertical connecting plate, which is equivalent to reducing the circumference of the outer support, so that the radius of the outer support can be reduced. Conversely, when it is necessary to increase the radius of the outer support, only the sliding direction of the slider needs to be away from the center of the steel arch support assembly, and the arc-shaped hydraulic cylinder needs to extend.

[0009] The radial yielding component is a vertical hydraulic cylinder, and the vertical hydraulic cylinder is arranged between the outer circumferential surface of the inner support and the arc-shaped inner bottom surface. The vertical hydraulic cylinder is used to adjust the radius of the outer support and can cooperate with the circumferential yielding component to play a synergistic role. When the vertical hydraulic cylinder contracts, it can drive the arc-shaped I-beam to contract inward, thereby realizing the reduction of the radius of the outer support. When the vertical hydraulic cylinder extends, it can drive the arc-shaped I-beam to extend outward, thereby realizing the increase of the radius of the outer support.

[0010] In the above steel arch support assembly, preferably, a buffer elastic body is provided between the sub-frame and the arc-shaped inner bottom surface, and the lower surface of the buffer elastic body is slidably arranged on the arc-shaped inner bottom surface. The buffer elastic body can better transfer the stress received by the sub-frame to the arc-shaped I-beam, further reducing the shear stress on the arc-shaped hydraulic cylinder, which is beneficial to the overall coordinated force of the external support. The buffer elastic body has a certain elasticity and can be compressed and self-reset.

[0011] In the present invention, by the cooperation of the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder, the radius of the external support can be adjusted within a large range. If only the arc-shaped hydraulic cylinder is used, due to the limited lengths of the vertical connecting plate and the guide rail, the sliding distance of the slider is limited, and the radius adjustment range of the external support is small. For Figure 2 example, when the slider slides to the bottom of the guide rail, the radius of the external support can no longer be adjusted at this time. If, after the slider slides to the bottom of the guide rail, the adjustment of the vertical hydraulic cylinder is further combined to drive the arc-shaped I-beam to slide downward, the position of the vertical connecting plate can be adjusted, thereby changing the relative position of the guide rail and the slider, and making the slider located above the guide rail. At this time, the radius of the external support can be further adjusted.

[0012] In the present invention, after the steel arch support assembly is erected, its side is enclosed by elastic concrete or partition boards, etc.

[0013] In the present invention, the contraction strokes of the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder are limited, specifically including: hydraulic cylinder, piston rod, valve, oil tank, hydraulic pump, control valve, etc. The hydraulic pump converts the kinetic energy of the motor into the pressure energy of the hydraulic oil, causing the hydraulic oil to generate high pressure. The hydraulic oil enters the suction port of the hydraulic pump and is transported to the hydraulic cylinder under the push of the pump. The piston rod in the hydraulic cylinder generates pressure on the other side under the action of the pressure of the hydraulic oil, thereby driving the piston rod to move. During the working process of the hydraulic cylinder, the pressure and flow rate of the hydraulic oil are two important parameters. The pressure of the hydraulic oil determines the output force of the hydraulic cylinder, and the flow rate of the hydraulic oil determines the movement speed of the hydraulic cylinder. By adjusting the pressure and flow rate in the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder, precise control of the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder can be achieved, so that the vertical yielding amount of the steel arch support assembly can be accurately controlled. For example, when it is necessary to increase the supporting force of the vertical hydraulic cylinder or the arc-shaped hydraulic cylinder, the pressure of the hydraulic oil can be increased.

[0014] In the above steel arch support assembly, preferably, the outer support is circumferentially and evenly divided into multiple sub-frames, and the inner support is an integral steel ring. The outer support is circumferentially and evenly divided, connected by arc-shaped I-beams, and then arranged outside the integral steel ring through vertical hydraulic cylinders, and a yielding support steel arch support assembly can be formed.

[0015] As a general technical concept, the present invention also provides a steel arch support system, including the above-mentioned steel arch support components, and a stress monitoring component for monitoring the change of surrounding rock stress is provided on the arc-shaped I-beam. The stress monitoring component can be used to monitor the change of surrounding rock stress, so as to facilitate the targeted adjustment of the steel arch support components to match the change of surrounding rock stress.

[0016] In the above-mentioned steel arch support system, preferably, the stress monitoring component includes a shape memory alloy layer provided on the outer side of the outer top surface of the arc and a current monitor connected to the shape memory alloy layer. The sub-frame bodies of the outer support are connected by arc-shaped I-beams. The outer radius of the arc-shaped I-beam is larger than the outer radius of the sub-frame body. The arc-shaped outer top surface of the arc-shaped I-beam is closer to the surrounding rock. It will first sense the change of surrounding rock stress. Setting the shape memory alloy layer on the outer side of the arc-shaped outer top surface can improve the perception accuracy of the change of surrounding rock stress, so as to accurately and quickly implement the yielding support strategy of the steel arch support components.

[0017] The present invention also includes a control system (which is a prior art). The arc-shaped hydraulic cylinders of the circumferential yielding component and the vertical hydraulic cylinders of the radial yielding component are both connected to the control system. The control system is connected to the stress monitoring component. By receiving the information provided by the stress monitoring component, the actions of the arc-shaped hydraulic cylinders and the vertical hydraulic cylinders are controlled to make their actions match each other.

[0018] As a general technical concept, the present invention also provides a support control method for the above-mentioned steel arch support system, including the following steps:

[0019] S1: When the stress monitoring component monitors that the surrounding rock stress received by a part of the steel arch support components increases, but does not increase to the ultimate bearing capacity of the steel arch support components in this section, increase the support force provided by the circumferential yielding component and the radial yielding component in this section to cope with the increase of the surrounding rock stress;

[0020] S2: When the stress monitoring component monitors that the surrounding rock stress received by a part of the steel arch support components increases to the ultimate bearing capacity of the steel arch support components in this section, reduce the distance between the ends of the adjacent sub-frame bodies in this section through the circumferential yielding component, so that the sub-frame bodies in this section shrink inward. At the same time, through the radial yielding component, the outer support in this section is shrunk inward as a whole to provide a space for the surrounding rock to undergo plastic deformation and release energy;

[0021] S3: As the surrounding rock stress decreases, when the stress monitoring component monitors that the surrounding rock stress received by a part of the steel arch support components is less than the ultimate bearing capacity of the steel arch support components in this section, the circumferential yielding component and the radial yielding component in this section stop moving.

[0022] More specifically, when the surrounding rock stress on a partial section of the steel arch support assembly increases to the ultimate bearing capacity of the steel arch support assembly in this section, the thrust of the hydraulic oil on the piston rod in the arc-shaped hydraulic cylinders in this part can be reduced, and the flow rate of the hydraulic oil can be controlled, so that the arc-shaped hydraulic cylinders in this part slowly retract. The movement direction is circumferential. At the same time, the slider moves towards the center of the steel arch support assembly, which can cause the outer support in this part to retract. The vertical hydraulic cylinders can also be simultaneously retracted to further reduce the radius of the outer support and provide more clearance space. During the retraction process, plastic deformation occurs in the surrounding rock, causing some of the energy in the surrounding rock to be released. After the surrounding rock stress weakens, the thrust of the hydraulic oil on the piston rod in the arc-shaped hydraulic cylinders or vertical hydraulic cylinders is increased, so that the arc-shaped hydraulic cylinders or vertical hydraulic cylinders stop retracting. At the same time, the slider stops moving, which can cause the outer support in this part to stop retracting and restore the supporting force of the steel arch support assembly on the surrounding rock in this section.

[0023] As a general technical concept, the present invention also provides a support control method for the above-mentioned steel arch support system, including the following steps:

[0024] S1: When the stress monitoring assembly monitors that the surrounding rock stress on all sections of the steel arch support assembly increases but does not increase to the ultimate bearing capacity of the steel arch support assembly, increase the support force provided by the circumferential yielding component and the radial yielding component to cope with the increase in the surrounding rock stress;

[0025] S2: When the stress monitoring assembly monitors that the surrounding rock stress on all sections of the steel arch support assembly increases to the ultimate bearing capacity of the steel arch support assembly, reduce the distance between the ends of adjacent sub-frames through the circumferential yielding component, cause the sub-frame to retract, and at the same time, cause the entire outer support to retract through the radial yielding component to provide clearance space for the plastic deformation of the surrounding rock to release energy;

[0026] S3: As the surrounding rock stress decreases, when the stress monitoring assembly monitors that the surrounding rock stress on all sections of the steel arch support assembly is less than the ultimate bearing capacity of the steel arch support assembly, the circumferential yielding component and the radial yielding component stop moving.

[0027] More specifically, when the surrounding rock stress on all steel arch support components increases to the ultimate bearing capacity of the steel arch support components, the thrust of the hydraulic oil on the piston rod in all vertical hydraulic cylinders can be reduced, and the flow rate of the hydraulic oil can be controlled so that all vertical hydraulic cylinders slowly contract inward, with the movement direction towards the center of the steel arch support component. At the same time, the thrust of the hydraulic oil on the piston rod in all arc-shaped hydraulic cylinders can be reduced, and the flow rate of the hydraulic oil can be controlled so that all arc-shaped hydraulic cylinders slowly contract inward, with the movement direction being circumferential. At the same time, the slider moves towards the center of the steel arch support component, which can cause all outer supports to contract inward. During the inward contraction process, plastic deformation occurs in the surrounding rock, causing some of the energy in the surrounding rock to be released. After the surrounding rock stress weakens, the thrust of the hydraulic oil on the piston rod in the arc-shaped hydraulic cylinder or vertical hydraulic cylinder is increased, causing the arc-shaped hydraulic cylinder or vertical hydraulic cylinder to stop contracting inward. At the same time, the slider stops moving, which can cause all outer supports to stop contracting inward and restore the support force of the steel arch support component on the surrounding rock.

[0028] In the above support control method, preferably, when the circumferential yielding component and the radial yielding component reach the limit of inward contraction, the inner support and the outer support are almost combined into a steel arch support component and can share the force together.

[0029] The present invention can control and adjust the support force of the steel arch support component through the circumferential yielding component and the radial yielding component, and is applicable to the steel arch support component of a circular cross-section tunnel. It has functions such as giving play to the self-bearing capacity of the surrounding rock, reasonably releasing the surrounding rock stress, and reasonably controlling the deformation amount of the surrounding rock, and can improve the bearing capacity of the circular steel arch support component. During the deformation process of the tunnel surrounding rock, by controlling the pressure and flow rate of the hydraulic oil, the movement direction and movement magnitude of the piston rod in the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder can be accurately controlled. Cooperating with the guide rail and the slider, the yielding value of the steel arch support component can be accurately controlled, realizing the support mode of support - strong support - yielding support - support, and achieving the effect of multi-stage treatment of the surrounding rock stress by the steel arch support component.

[0030] Specifically, the first support stage is that after the initial installation of the steel arch support assembly, it has a corresponding supporting force on the surrounding rock, and at this time, the steel arch support assembly is far from reaching its ultimate bearing capacity. The second strong support stage is that after the initial installation of the steel arch support assembly, as time goes by, the stress of the surrounding rock changes. Although it does not reach the ultimate bearing capacity of some or the whole steel arch support assembly, at this time, it is necessary to increase the strength and stiffness of some or the whole steel arch support assembly, and increase the hydraulic oil pressure of the vertical hydraulic cylinders and arc-shaped hydraulic cylinders in the radial yielding assembly and circumferential yielding assembly, so that the supporting force of the vertical hydraulic cylinders and arc-shaped hydraulic cylinders on the steel arch support assembly increases, thereby strengthening the strength and stiffness of the steel arch support assembly. The third yielding support stage is that as time goes by, the stress of the surrounding rock becomes larger and larger. When some or the whole steel arch support assembly gradually reaches its ultimate bearing capacity, the pressure of the hydraulic oil in the vertical hydraulic cylinders and arc-shaped hydraulic cylinders is reduced, and the flow rate of the hydraulic oil is controlled. At the same time, the slider moves towards the center of the steel arch support assembly, so that some or the whole steel arch support assembly slowly starts to shrink inwards. During the inward shrinkage process, the surrounding rock undergoes plastic deformation, so that part of the energy in the surrounding rock is released. The fourth support stage is that when some or the whole steel arch support assembly shrinks inwards by a certain value, the energy of the surrounding rock at this time weakens, and the pressure of the hydraulic oil in the vertical hydraulic cylinders and arc-shaped hydraulic cylinders is restored. At the same time, the slider stops sliding, so that some or the whole steel arch support assembly stops shrinking inwards. At this time, the steel arch support assembly returns to the first stage again.

[0031] The above process of support - strong support - yielding support - support can occur cyclically during the support process of the steel arch support assembly, enabling the steel arch support assembly to reasonably analyze the state of the surrounding rock, provide reasonable support, and achieve reasonable yielding.

[0032] Compared with the prior art, the advantages of the present invention are as follows:

[0033] The steel arch support assembly, steel arch support system and its support control method for circular-section tunnels of the present invention can control and adjust the supporting force of the steel arch support assembly through the circumferential yielding assembly and radial yielding assembly, can provide corresponding supporting force for the change of the surrounding rock stress, accurately control the local and overall yielding amounts, achieve the effect of multi-stage treatment of the surrounding rock stress by the steel arch support assembly, and can improve the bearing capacity of the circular-section steel arch support assembly. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic structural diagram of the steel arch support assembly in the embodiment.

[0036] Figure 2 It is a schematic structural diagram of the first circumferential yielding component in the embodiment.

[0037] Figure 3 It is a schematic structural diagram of the second circumferential yielding component in the embodiment.

[0038] Figure 4 It is a schematic structural diagram of the radial yielding component in the embodiment.

[0039] Figure 5 It is a schematic structural diagram of the steel arch support system in the embodiment.

[0040] Legend Explanation

[0041] 1. Inner support; 2. Outer support; 21. Sub-frame; 3. Circumferential yielding component; 31. Arc-shaped hydraulic cylinder; 32. Guide rail; 33. Slide block; 4. Radial yielding component; 5. Arc-shaped I-beam; 51. Arc-shaped outer top surface; 52. Arc-shaped inner bottom surface; 53. Vertical connecting plate; 6. Buffer elastic body; 7. Stress monitoring component; 71. Memory alloy layer; 72. Current monitor. Detailed Embodiment

[0042] For the convenience of understanding the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings of the specification and preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0043] It should be specifically noted that when a certain element is described as "fixed to, fixedly connected to, connected to or communicated with" another element, it can be directly fixed, fixedly connected, connected or communicated to the other element, or indirectly fixed, fixedly connected, connected or communicated to the other element through other intermediate connecting members.

[0044] Unless otherwise defined, all the professional terms used hereinafter have the same meanings as those commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0045] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0046] Embodiment:

[0047] As Figure 1As shown in the figure, the steel arch support assembly for a circular cross-section tunnel in this embodiment includes an inner support 1 and an outer support 2. The inner support 1 is an integral steel ring, and the outer support 2 is a split structure that is circumferentially and evenly divided into eight sub-frame bodies 21. An arc-shaped I-beam 5 is provided between adjacent sub-frame bodies 21. A circumferential yielding component 3 for controlling the distance between the ends of adjacent sub-frame bodies 21 is provided between the adjacent ends of adjacent sub-frame bodies 21 and the arc-shaped I-beam 5. A radial yielding component 4 for controlling the radius of the outer support 2 is provided between the inner support 1 and the arc-shaped I-beam 5.

[0048] In other embodiments, the outer support 2 can also be a split structure that is circumferentially and evenly divided into other numbers of sub-frame bodies 21.

[0049] As Figure 2 shown in the figure, in this embodiment, the arc-shaped I-beam 5 includes an arc-shaped outer top surface 51 and an arc-shaped inner bottom surface 52. A vertical connecting plate 53 is provided between the arc-shaped outer top surface 51 and the arc-shaped inner bottom surface 52. The circumferential yielding component 3 is provided between the end of the sub-frame body 21 and the vertical connecting plate 53, and the radial yielding component 4 is provided between the inner support 1 and the arc-shaped inner bottom surface 52.

[0050] In this embodiment, the circumferential yielding component 3 includes an arc-shaped hydraulic cylinder 31, a guide rail 32, and a slider 33. The guide rail 32 is provided on the vertical connecting plate 53 and is arranged parallel to the vertical connecting plate 53. The slider 33 is slidably arranged on the guide rail 32. One end of the arc-shaped hydraulic cylinder 31 is provided at the end of the sub-frame body 21, and the other end is provided on the slider 33.

[0051] As Figure 3 shown in the figure, in other embodiments, a buffer elastic body 6 is provided between the sub-frame body 21 and the arc-shaped inner bottom surface 52, and the lower surface of the buffer elastic body 6 is slidably arranged on the arc-shaped inner bottom surface 52.

[0052] As Figure 4 shown in the figure, in this embodiment, the radial yielding component 4 is a vertical hydraulic cylinder, and the vertical hydraulic cylinder is provided between the outer circumferential surface of the inner support 1 and the arc-shaped inner bottom surface 52.

[0053] As Figure 5 shown in the figure, the steel arch support system in this embodiment includes the above-mentioned steel arch support assembly. A stress monitoring component 7 for monitoring the stress change of the surrounding rock is provided on the arc-shaped I-beam 5. The stress monitoring component 7 includes a shape memory alloy layer 71 provided on the outside of the arc-shaped outer top surface 51 and a current monitor 72 connected to the shape memory alloy layer 71.

[0054] The support control method of the steel arch support system in this embodiment for some sections includes the following steps:

[0055] S1: When the stress monitoring component 7 monitors that the surrounding rock stress on some sections of the steel arch support component increases but does not increase to the ultimate bearing capacity of the steel arch support component in these sections, increase the support force provided by the circumferential yielding component 3 and the radial yielding component 4 in these sections to cope with the increase in the surrounding rock stress;

[0056] S2: When the stress monitoring component 7 monitors that the surrounding rock stress on some sections of the steel arch support component increases to the ultimate bearing capacity of the steel arch support component in these sections, reduce the distance between the ends of adjacent sub - frames 21 in these sections through the circumferential yielding component 3 to make the sub - frames 21 in these sections contract inward. At the same time, make the outer support 2 in these sections contract inward through the radial yielding component 4 to provide a space for the surrounding rock to release energy during plastic deformation;

[0057] S3: As the surrounding rock stress decreases, when the stress monitoring component 7 monitors that the surrounding rock stress on some sections of the steel arch support component is less than the ultimate bearing capacity of the steel arch support component in these sections, the circumferential yielding component 3 and the radial yielding component 4 in these sections stop moving.

[0058] The support control method of the steel arch support system in this embodiment for all sections includes the following steps:

[0059] S1: When the stress monitoring component 7 monitors that the surrounding rock stress on all sections of the steel arch support component increases but does not increase to the ultimate bearing capacity of the steel arch support component, increase the support force provided by the circumferential yielding component 3 and the radial yielding component 4 to cope with the increase in the surrounding rock stress;

[0060] S2: When the stress monitoring component 7 monitors that the surrounding rock stress on all sections of the steel arch support component increases to the ultimate bearing capacity of the steel arch support component, reduce the distance between the ends of adjacent sub - frames 21 through the circumferential yielding component 3 to make the sub - frames 21 contract inward. At the same time, make the outer support 2 contract inward through the radial yielding component 4 to provide a space for the surrounding rock to release energy during plastic deformation;

[0061] S3: As the surrounding rock stress decreases, when the stress monitoring component 7 monitors that the surrounding rock stress on all sections of the steel arch support component is less than the ultimate bearing capacity of the steel arch support component, the circumferential yielding component 3 and the radial yielding component 4 stop moving.

[0062] In this embodiment, the support force of the steel arch support assembly can be controlled and adjusted through the circumferential yielding assembly 3 and the radial yielding assembly 4. It is applicable to the steel arch support assembly of circular-section tunnels, and has functions such as giving play to the self-bearing capacity of the surrounding rock, reasonably releasing the stress of the surrounding rock, and reasonably controlling the deformation amount of the surrounding rock, and can improve the bearing capacity of the circular steel arch support assembly. During the deformation process of the tunnel surrounding rock, by controlling the pressure and flow rate of the hydraulic oil, the movement direction and magnitude of the piston rods in the vertical hydraulic cylinder and the arc-shaped hydraulic cylinder 31 can be accurately controlled. Cooperating with the guide rail 32 and the slider 33, the yielding value of the steel arch support assembly can be accurately controlled, realizing the support mode of support - strong support - yielding support - support, and achieving the effect of multi-stage treatment of the surrounding rock stress by the steel arch support assembly.

[0063] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A steel arch support assembly for a circular cross-section tunnel, characterized in that: It comprises an inner support (1) and an outer support (2), the outer support (2) being a split structure divided into a plurality of sub-frames (21) in an annular direction, an arc-shaped I-beam (5) being provided between adjacent sub-frames (21), an annular pressure-relief assembly (3) for controlling the distance between adjacent ends of the sub-frames (21) being provided between adjacent ends of the adjacent sub-frames (21) and the arc-shaped I-beam (5), and a radial pressure-relief assembly (4) for controlling the radius of the outer support (2) being provided between the inner support (1) and the arc-shaped I-beam (5); The arc-shaped I-beam (5) comprises an arc-shaped outer top surface (51) and an arc-shaped inner bottom surface (52), a vertical connecting plate (53) is provided between the arc-shaped outer top surface (51) and the arc-shaped inner bottom surface (52), the annular pressure-releasing assembly (3) is provided between the end of the sub-frame (21) and the vertical connecting plate (53), and the radial pressure-releasing assembly (4) is provided between the inner support (1) and the arc-shaped inner bottom surface (52); The annular pressure-releasing assembly (3) comprises an arc-shaped hydraulic cylinder (31), a guide rail (32) and a slide block (33); the guide rail (32) is arranged on the vertical connecting plate (53) and is arranged parallel to the vertical connecting plate (53); the slide block (33) is slidably arranged on the guide rail (32); one end of the arc-shaped hydraulic cylinder (31) is arranged on the end of the sub-frame (21), and the other end is arranged on the slide block (33); The radial pressure relief assembly (4) is a vertical hydraulic cylinder, and the vertical hydraulic cylinder is arranged between the outer ring surface of the inner support (1) and the arc-shaped inner bottom surface (52).

2. The steel arch support assembly according to claim 1, characterized in that: A buffer elastic body (6) is provided between the sub-frame body (21) and the arc-shaped inner bottom surface (52), and the buffer elastic body (6) is slidably provided on the arc-shaped inner bottom surface (52).

3. The steel arch support assembly according to claim 1, characterized in that: The outer support (2) is evenly divided into a plurality of sub-frames (21) in the circumferential direction, and the inner support (1) is an integral steel ring.

4. A steel arch support system, characterized in that: It comprises the steel arch support assembly according to any one of claims 1 to 3, wherein the arc-shaped I-beam (5) is provided with a stress monitoring assembly (7) for monitoring changes in surrounding rock stress.

5. The steel arch support system according to claim 4, characterized in that: The stress monitoring component (7) comprises a memory alloy layer (71) arranged outside the arc-shaped outer top surface (51) and a current monitor (72) connected to the memory alloy layer (71).

6. A support control method for a steel arch support system according to claim 4 or 5, characterized in that: The following steps are involved: S1: When the stress monitoring component (7) detects that the surrounding rock stress in a part of the section of the steel arch support component increases but does not increase to the ultimate bearing capacity of the steel arch support component in the section, the supporting force provided by the annular yielding component (3) and the radial yielding component (4) in the section is increased to cope with the increase in surrounding rock stress; S2: When the stress monitoring component (7) detects that the surrounding rock stress on a part of the section of the steel arch support component increases to the ultimate bearing capacity of the steel arch support component of the section, the distance between the ends of the adjacent sub-frames (21) of the section is reduced by the annular pressure-yielding component (3), so that the sub-frames (21) of the section are retracted, and at the same time, the outer support (2) of the section is retracted as a whole by the radial pressure-yielding component (4), so as to provide an escape space for the surrounding rock to release energy through plastic deformation; S3: As the surrounding rock stress decreases, when the stress monitoring component (7) detects that the surrounding rock stress on a partial section of the steel arch support component is less than the ultimate bearing capacity of the steel arch support component in this section, the annular pressure-yielding component (3) and the radial pressure-yielding component (4) in this section stop moving.

7. A support control method for a steel arch support system according to claim 4 or 5, characterized in that: The following steps are involved: S1: When the stress monitoring component (7) detects that the surrounding rock stress in all sections of the steel arch support component increases but does not increase to the ultimate bearing capacity of the steel arch support component, the supporting force provided by the annular yielding component (3) and the radial yielding component (4) is increased to cope with the increase in surrounding rock stress; S2: When the stress monitoring component (7) detects that the surrounding rock stress in all sections of the steel arch support component increases to the ultimate bearing capacity of the steel arch support component, the distance between the ends of the adjacent sub-frames (21) is reduced through the annular pressure-yielding component (3), so that the sub-frames (21) are retracted, and at the same time, the outer support (2) is retracted as a whole through the radial pressure-yielding component (4), so as to provide an escape space for the surrounding rock to release energy through plastic deformation; S3: As the surrounding rock stress decreases, when the stress monitoring component (7) detects that the surrounding rock stress on all sections of the steel arch support component is less than the ultimate bearing capacity of the steel arch support component, the annular yielding component (3) and the radial yielding component (4) stop moving.

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