A steel arch support structure tensioning device and method for TBM construction

Abstract

The present application relates to the technical field of tunnel engineering construction equipment, and discloses a steel arch support structure tightening device and method for TBM construction. The present application aims to solve the technical problem that the annular steel arch cannot be closely attached to the surrounding rock and causes bearing failure in the TBM construction process due to overbreak, collapse, processing errors and other factors. The present application comprises a square steel, the internal cavity size of which is larger than the external contour size of the H-shaped steel used for steel arch segmenting, and the curvature of the square steel is the same as that of the steel arch, so as to be sleeved outside the butt joint end of adjacent two steel arch segments. The present application adopts a screw thread block screw transmission structure, and the continuous stepless extension of the supporting bolt and the block can be realized by rotating the bolt, the supporting force adjustment is accurate and stable, the over-supporting damage or under-supporting non-tightness problem caused by traditional wedge hammering is effectively avoided, and the active support effect of the steel arch on the surrounding rock is ensured.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction equipment technology, and in particular to a steel arch support structure tightening device and method for use in TBM construction. Background Technology

[0002] In tunnel construction, the TBM (Tunnel Boring Machine) method has become the mainstream construction technology for long tunnels due to its significant advantages such as high-efficiency excavation, safety and reliability, and minimal disturbance to the surrounding rock. Steel arch frames, as the core load-bearing structure in the initial support system for tunnels with Class III or higher surrounding rock and rockburst sections, typically need to work in conjunction with shotcrete and systematic anchor bolts to form a "flexible-to-rigid, rigid-flexible combined" support system. This effectively controls surrounding rock deformation and prevents disasters such as collapses and rockfalls.

[0003] However, during TBM tunneling, the installation quality of steel arch frames is often difficult to guarantee due to the combined effects of various engineering factors. Specifically, factors such as over-excavation of the tunnel excavation profile, irregular collapse of local surrounding rock, and cumulative errors in the processing and assembly of steel arch frames prevent the steel arch frames from tightly fitting the surrounding rock surface. This poor fit directly leads to the following prominent problems: first, the arch frame posture becomes skewed during arch erection, deviating from the design axis; second, the spacing between adjacent steel arch frames is uneven, failing to meet the equidistant layout required by the design. These installation deviations not only weaken the overall load-bearing capacity of the initial support—the steel arch frames cannot effectively bear the pressure of the surrounding rock—but also prevent the steel arch frames from accurately aligning with the support shoe slots in the TBM's subsequent supporting system, thus affecting the normal expansion, contraction, and locking functions of the support shoes.

[0004] The aforementioned problems seriously threaten the construction safety, lining quality, and excavation progress of TBM tunnels. On the one hand, unreasonable stress on the support structure may induce rock instability and increase the risk of collapse; on the other hand, frequent corrections and rework lead to decreased construction efficiency and may even force the TBM to stop and wait. Currently, for problems such as the steel arch frame becoming detached from the surrounding rock and the arch tilting, simple methods such as wedge-shaped pads and temporary supports are often used for local adjustments on the construction site, but the effect is limited and there is a lack of systematic and standardized solutions. Therefore, it is urgent to develop a steel arch frame tensioning device with a reasonable structure, convenient operation, and strong adaptability, as well as its supporting construction method, to effectively compensate for the gaps caused by over-excavation and collapse, ensure that the arch frame is closely fitted to the surrounding rock, has an accurate posture, and uniform spacing, thereby improving the overall reliability and construction efficiency of the initial support and overcoming the shortcomings of existing technologies. Summary of the Invention

[0005] In view of the above technical problems, this disclosure provides a steel arch support structure tightening device and method for TBM construction, which solves the technical problem in the prior art that the annular steel arch cannot be tightly attached to the surrounding rock and thus fails to bear the load due to over-excavation, collapse, processing errors and other factors during TBM construction.

[0006] According to one aspect of this disclosure, a steel arch support structure tightening device for TBM construction is provided, comprising a square steel section, wherein the internal cavity size of the square steel section is larger than the external contour size of the H-beams used for the steel arch section segments, and the curvature of the square steel section is the same as the curvature of the steel arch section, for fitting onto the outer side of the mating ends of two adjacent steel arch section segments.

[0007] The square steel section has through holes at off-center positions, and internal support components are installed in the internal cavity of the square steel section through the through holes;

[0008] The inner support assembly includes a bolt installed in a through hole, the bolt passing through a fastening nut, the through hole, a threadless slider, and threadedly connected to a threaded washer.

[0009] The internal support assembly also includes a left pad and a right pad located on both sides of the through hole, and the left pad and the right pad are connected by a support bolt; the end of the support bolt is unidirectionally hinged to the left pad and the right pad, and is used to abut against the web of the steel arch frame segment.

[0010] The total length of the unthreaded slider and the threaded pad is less than the width of the internal cavity of the square steel section.

[0011] It also includes a steel arch frame splicing mechanism, used to grab two adjacent steel arch frames and perform docking and splicing operations; the steel arch frame splicing mechanism includes two symmetrically arranged splicing arms, and an actuator is connected to the end of each splicing arm;

[0012] The splicing arm includes a base rotation joint for rotating the entire splicing arm to reach the working position; the base rotation joint is connected to a first link, the first link is connected to a second link via an intermediate rotation joint; the second link is connected to an actuator via an end rotation joint.

[0013] The actuator includes a frame, with an upper jaw for clamping from above the steel arch frame and a lower jaw for supporting from below the steel arch frame.

[0014] In some embodiments of this disclosure, the steel arch frame is a snap-fit ​​steel arch frame, with a U-shaped buckle at one end and a self-locking hole with an elastic buckle tongue at the other end. The splicing mechanism inserts the U-shaped buckle into the self-locking hole by pressing down to complete the self-locking connection.

[0015] In some embodiments of this disclosure, the through holes on the square steel section are offset to one side of the square steel section to avoid the end of the inserted H-beam and to provide installation space for the inner support assembly.

[0016] In some embodiments of this disclosure, the length of the support bolt is set as an adjustable structure according to the spacing of the bottom segmented arch frame.

[0017] In some embodiments of this disclosure, the fastening nut is disposed on the outer side wall of the square steel section and is used to apply preload through the bolt to limit the deformation and yielding of the square steel section.

[0018] A steel arch support structure includes an annular arch frame formed by multiple H-shaped steel arch sections connected by bolts to end connecting plates. At the connection point of two adjacent sections on the lowest side of the annular arch frame, the aforementioned steel arch support structure tensioning device for TBM construction is provided.

[0019] The square steel section is sleeved on the outside of the two segments at the connection point, and the pad in the inner support assembly is tightly supported in the middle of the web of the two segments.

[0020] In some embodiments of this disclosure, the steel arch frame consists of five pieces: a top section and four symmetrically arranged lateral sections.

[0021] A method for tightening steel arch frames in TBM tunnels, applicable to the aforementioned tightening device for steel arch frame support structures in TBM construction; comprising the following steps:

[0022] S1: Tighten the assembled steel arch frame, determine the spacing between the bottom sections, and select the required length of the tightening device. The maximum tightening length of the tightening device is:

[0023] ;

[0024] Minimum tensioning length of the tensioning device:

[0025] ;

[0026] Where a is the length of the support bolt, b is the thickness of the pad block, c is the thickness of the threaded pad block, and the internal height of the square steel section is 2h;

[0027] S2: Install the tensioning device into the inside of the square steel section; insert the inner support from one side of the hole, and pass the bolt through the fastening nut, the opening of the square steel section, the unthreaded slider and the threaded washer in sequence, and adjust the fastening nut to the top.

[0028] S3: Insert the H-beam end into the square steel section; first insert it from the side farther from the opening, then insert it from the side closer to the opening;

[0029] S4: Tighten the inner support, rotate the bolt to bring the threaded pad closer to the surrounding rock, and the support bolt gradually tightens the steel arch frame through the pad. When the steel arch frame is close to the surrounding rock, stop rotating the bolt and adjust the fastening nut to the lower side of the bolt so that the bolt becomes the main load-bearing structure of the device.

[0030] The beneficial effects of this invention are as follows:

[0031] The tensioning force is precisely controllable, ensuring a close fit between the arch frame and the surrounding rock. It adopts a spiral drive structure of bolts and threaded blocks, which can achieve continuous stepless outward pushing of the bolts and blocks by rotating the bolts. The tensioning force is precisely and smoothly adjusted, effectively avoiding the problems of over-stretching damage or under-stretching and non-close fit caused by traditional wedge block hammering, thus ensuring the active support effect of the steel arch frame on the surrounding rock.

[0032] The force-bearing system is clearly defined, and the structure has high rigidity. After the bracing is completed, the fastening nut is locked to the underside of the bolt and a preload is applied, making the bolt the main tension member of the device and limiting the deformation and yielding of the square steel under stress. At the same time, the bracing bolt, the pad, and the inner wall of the square steel form a stable triangular force transmission path, which significantly improves the bending stiffness and overall stability at the joint of the steel arch frame.

[0033] The device is easy to install and adaptable to narrow working spaces. It adopts a pre-installed, integral installation method. All the adjustment operations of the internal support components are concentrated at the through hole on one side of the square steel, which greatly facilitates the rapid installation and tightening operation in the limited space behind the TBM shield, shortens the support time, and improves construction efficiency.

[0034] With strong adaptability, it compensates for manufacturing and installation errors. By adjusting the length of the support bolts and the adjustable stroke of the threaded pads, the device can flexibly adapt to the actual spacing changes of the bottom segments of the steel arch frame, effectively compensate for processing deviations and gaps caused by over-excavation of the surrounding rock, and ensure effective tightening under various working conditions.

[0035] With a simple structure, low cost, and convenient maintenance, the device is mainly composed of conventional components such as square steel, bolts, pads, and support bolts. It is easy to process and manufacture, does not require a complex hydraulic or electrical control system, and all components are detachable, making it easy to replace and reuse on site, resulting in good economic efficiency.

[0036] The lower jaw provides stable support from the bottom to bear the weight of the arch frame, while the upper jaw applies pressure from the top to clamp it. Compared to single-sided clamping, this structure effectively resists reaction forces during the downward pressing action of the splicing mechanism, preventing the steel arch frame from slipping due to uneven stress and improving operational safety. The three-degree-of-freedom tandem mechanism allows the actuator to flexibly adjust its posture in narrow tunnel spaces, compensating for positional deviations during the hoisting of the steel arch frame and reducing the risk of jamming. Insertion and locking are completed in one go through the downward pressing action of the splicing mechanism. No additional welding, bolt tightening, or manual assistance with pins is required, significantly shortening the splicing time of a single-ring arch frame. The two symmetrically arranged splicing arms can operate independently or in tandem. During the splicing process, one arm can hold the fixed arch frame as a reference, while the other arm holds the new arch frame for active alignment, effectively eliminating cumulative installation deviations caused by uneven ground or trolley positioning errors. This device is compatible with snap-fit ​​arch frames and various cross-section types. The actuator's clamping range and the three-joint arm's movement space can accommodate steel arch frames of different arc lengths and curvatures. It can be used for splicing arch frames of different specifications in Class V or Class IV rock conditions without changing tooling, demonstrating strong versatility. The elastic snap-fit ​​tongue pops out after full insertion, indicating proper locking. This mechanical anti-detachment structure is unaffected by hydraulic leaks or electrical faults, making it intrinsically safe. Combined with sensors, the locking status of each splicing point can be confirmed. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the entire steel arch frame structure;

[0038] Figure 2 This is a schematic diagram of the installation of the steel arch support structure tensioning device used in TBM construction;

[0039] Figure 3 This is a schematic diagram of the steel arch frame splicing mechanism.

[0040] Figure 4 This is a schematic diagram of a snap-fit ​​steel arch frame structure.

[0041] Figure 5 This is a front view of a snap-fit ​​steel arch frame;

[0042] Figure 6 Top view of the snap-fit ​​steel arch frame;

[0043] Figure 7 for Figure 6 Sectional view of plane AA;

[0044] The components in the diagram are named as follows: 1 is the whole steel arch frame; 2 is the connection point of the segmented arch frame; 3 is the bottom connection point of the segmented arch frame; 4 is the square steel section; 5 is the bolt; 6 is the right pad; 7 is the support bolt; 8 is the threaded pad; 9 is the unthreaded slider; 10 is the fastening nut; 11 is the left pad; 12 is the steel arch frame splicing mechanism; 13 is the splicing arm; 14 is the base rotation joint; 15 is the first connecting rod; 16 is the intermediate rotation joint; 17 is the second connecting rod; 18 is the end rotation joint; 19 is the frame; 20 is the upper jaw; 21 is the lower jaw; 22 is the steel arch frame; 23 is the U-shaped buckle seat; 24 is the self-locking hole; 25 is the elastic buckle tongue. Detailed Implementation

[0045] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0046] Example 1

[0047] This example discloses a tensioning device for steel arch support structures used in TBM construction. (See also...) Figures 1 to 7 ,

[0048] Includes square steel section 4, the internal cavity size of square steel section 4 is larger than the external outline size of H-beams used in steel arch frame segments, and the curvature of square steel section 4 is the same as the curvature of steel arch frame, used to fit on the outside of the joint ends of two adjacent steel arch frame segments;

[0049] A through hole is made in the square steel section 4 at an off-center position, and an internal support component is installed in the internal cavity of the square steel section 4 through the through hole;

[0050] The internal support assembly includes a bolt 5 installed in a through hole, which passes through a fastening nut 10, the through hole, a threadless slider 9, and is threadedly connected to a threaded washer 8.

[0051] The internal support assembly also includes a left pad 11 and a right pad 6 located on both sides of the through hole, and the left pad and the right pad are connected by a support bolt 7; the end of the support bolt 7 is unidirectionally hinged to the left pad 11 and the right pad 6 to abut against the web of the steel arch frame segment.

[0052] The total length of the unthreaded slider 9 and the threaded pad 8 is less than the width of the internal cavity of the square steel section 4.

[0053] It also includes a steel arch frame splicing mechanism 12, which is used to grab two adjacent steel arch frames and perform docking splicing operations; the steel arch frame splicing mechanism 12 includes two symmetrically arranged splicing arms 13, and the end of each splicing arm 13 is connected to an actuator.

[0054] The splicing arm 13 includes a base rotation joint 14, which is used to drive the entire splicing arm 13 to rotate to reach the working position; the base rotation joint 14 is connected to the first link 15, the first link 15 is connected to the second link 17 via the intermediate rotation joint 16; the second link 17 is connected to the actuator via the end rotation joint 18.

[0055] The actuator includes a frame 19, with an upper jaw 20 on the top of the frame 19 for clamping from above the steel arch frame 22, and a lower jaw 21 on the bottom of the frame for supporting from below the steel arch frame 22.

[0056] The steel arch frame 22 is a snap-fit ​​steel arch frame. One end of the steel arch frame 22 is provided with a U-shaped buckle 23, and the other end is provided with a self-locking hole 24 with an elastic buckle tongue 25. The splicing mechanism inserts the U-shaped buckle 23 into the self-locking hole 24 through a downward pressing action to complete the self-locking connection.

[0057] During operation, two symmetrically arranged splicing arms 13 rotate via base rotation joints 14, moving the end effector from its standby position to a working position to the side of the two steel arch frames to be spliced. The intermediate rotation joint 16 and the end rotation joint 18 work together to adjust the pitch and yaw angles of the second link 17 and the actuator, aligning the upper jaw 20 and lower jaw 21 on the actuator with the upper and lower flanges of the steel arch frame 22. The lower jaw 21 first extends under the steel arch frame 22 to provide support, then the upper jaw 20 presses down from above to clamp and firmly fix the steel arch frame to the frame 19. The two arms respectively grasp two adjacent arch frames. The two splicing arms 13 work together to align the U-shaped buckle 23 end of one arch frame with the self-locking hole 24 end of the other arch frame, adjusting them to be coaxial and parallel. During insertion, the elastic buckle tongue 25 is pressed down, passes through the self-locking hole, and springs back up, achieving mechanical anti-detachment self-locking. At this point, the upper / lower jaws on the splicing arm 13 release and retract, completing the splicing of one arch frame, and then moving on to the next frame.

[0058] The through holes on the square steel section 4 are offset to one side of the square steel section 4 to avoid the end of the inserted H-section steel and to provide installation space for the internal support assembly.

[0059] The length of the support bolt 7 is set as an adjustable structure according to the spacing of the bottom segmented arch frame.

[0060] The fastening nut 10 is set on the outer wall of the square steel section 4 and is used to apply preload through the bolt to limit the deformation and yielding of the square steel section.

[0061] A steel arch support structure includes a whole steel arch 1. The whole steel arch 1 includes an annular arch frame formed by multiple H-shaped steel arch sections connected by end connecting plates and bolts. At the connection point of two adjacent sections on the lowest side of the annular arch frame, a tensioning device for the steel arch support structure during TBM construction is provided.

[0062] Four square steel sections are set on the outside of the two segments at the connection point, and the pads in the inner support assembly are tightened in the middle of the web of the two segments.

[0063] The steel arch frame consists of five parts: a top section and four symmetrically arranged lateral sections. The lateral sections are connected by section arch frame connection point 2, and the two bottom sections are connected by section arch frame bottom connection point 3.

[0064] A method for tightening steel arch frames in TBM tunnels, applicable to steel arch frame support structures in TBM construction; comprising the following steps:

[0065] S1: Tighten the assembled steel arch frame, determine the spacing between the bottom sections, and select the required length of the tightening device. The maximum tightening length of the tightening device is:

[0066] ;

[0067] Minimum tensioning length of the tensioning device:

[0068] ;

[0069] Where a is the length of the support bolt, b is the thickness of the pad block, c is the thickness of the threaded pad block, and the internal height of the square steel section is 2h;

[0070] S2: Install the tensioning device into the inside of the square steel section; insert the inner support from one side of the hole, and pass the bolt through the fastening nut, the opening of the square steel section, the unthreaded slider and the threaded washer in sequence, and adjust the fastening nut to the top.

[0071] S3: Insert the H-beam end into the square steel section; first insert it from the side farther from the opening, then insert it from the side closer to the opening;

[0072] S4: Tighten the inner support, rotate the bolt to bring the threaded pad closer to the surrounding rock, and the support bolt gradually tightens the steel arch frame through the pad. When the steel arch frame is close to the surrounding rock, stop rotating the bolt and adjust the fastening nut to the lower side of the bolt so that the bolt becomes the main load-bearing structure of the device.

[0073] Although some preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0074] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A steel arch support structure bracing device for use in TBM construction, characterized by: It includes square steel sections, the internal cavity size of which is larger than the external outline size of the H-beams used for the steel arch frame segments, and the curvature of the square steel sections is the same as the curvature of the steel arch frame, and is used to fit on the outside of the joint ends of two adjacent steel arch frame segments. The square steel section has through holes at off-center positions, and internal support components are installed in the internal cavity of the square steel section through the through holes; The inner support assembly includes a bolt installed in a through hole, the bolt passing through a fastening nut, the through hole, a threadless slider, and threadedly connected to a threaded washer. The internal support assembly also includes a left pad and a right pad located on both sides of the through hole, and the left pad and the right pad are connected by a support bolt; the end of the support bolt is unidirectionally hinged to the left pad and the right pad, and is used to abut against the web of the steel arch frame segment. The total length of the unthreaded slider and the threaded pad is less than the width of the internal cavity of the square steel section.

2. The steel arch support structure tightening device for TBM construction as described in claim 1, characterized in that: It also includes a steel arch frame splicing mechanism, used to grab two adjacent steel arch frames and perform docking and splicing operations; the steel arch frame splicing mechanism includes two symmetrically arranged splicing arms, and an actuator is connected to the end of each splicing arm; The splicing arm includes a base rotation joint, which is used to drive the entire splicing arm to rotate to reach the working position; The base rotation joint is connected to the first link, and the first link is connected to the second link via an intermediate rotation joint; The second link is connected to the actuator via an end joint; The actuator includes a frame, with an upper jaw for clamping from above the steel arch frame and a lower jaw for supporting from below the steel arch frame.

3. The strutting device for steel arch support structure in TBM construction according to claim 2, characterized in that: The steel arch frame is a snap-fit ​​type steel arch frame. One end of the steel arch frame is provided with a U-shaped buckle, and the other end is provided with a self-locking hole with an elastic buckle tongue. The splicing mechanism completes the self-locking connection by pressing down to insert the U-shaped buckle into the self-locking hole.

4. The strutting device for steel arch support structure in TBM construction according to claim 1, characterized in that: The through holes on the square steel section are offset to one side of the square steel section to avoid the end of the inserted H-shaped steel section and to provide installation space for the internal support assembly.

5. The steel arch support structure tightening device for TBM construction as described in claim 1, characterized in that: The length of the support bolt is set as an adjustable structure according to the spacing of the bottom segmented arch frame.

6. The steel arch support structure tightening device for TBM construction as described in claim 1, characterized in that: The fastening nut is located on the outer wall of the square steel section and is used to apply preload through the bolt to limit the deformation and yielding of the square steel section.

7. A steel arch support structure, characterized in that, It includes an annular arch frame consisting of multiple H-shaped steel arch sections connected by bolts to end connecting plates. At the connection point of two adjacent sections on the lowest side of the annular arch frame, a steel arch frame support structure tensioning device as described in claim 1 is provided. The square steel section is sleeved on the outside of the two segments at the connection point, and the pad in the inner support assembly is tightly supported in the middle of the web of the two segments.

8. The steel arch support structure as described in claim 7, characterized in that: The steel arch frame consists of five parts: a top section and four symmetrically arranged lateral sections.

9. A method for tightening steel arch frames in TBM tunnels, applicable to the steel arch frame support structure tightening device as described in claim 1; characterized in that, Includes the following steps: S1: Tighten the assembled steel arch frame, determine the spacing between the ends of the bottom sections, and select the required length of tightening device. Maximum tensioning length of the tensioning device: ; Minimum tensioning length of the tensioning device: ; Where a is the length of the support bolt, b is the thickness of the pad block, c is the thickness of the threaded pad block, and the internal height of the square steel section is 2h; S2: Install the tensioning device into the inside of the square steel section; insert the inner support from one side of the hole, and pass the bolt through the fastening nut, the opening of the square steel section, the unthreaded slider and the threaded washer in sequence, and adjust the fastening nut to the top. S3: Insert the H-beam end into the square steel section; first insert it from the side farther from the opening, then insert it from the side closer to the opening; S4: Tighten the inner support, rotate the bolt to bring the threaded pad closer to the surrounding rock, and the support bolt gradually tightens the steel arch frame through the pad. When the steel arch frame is close to the surrounding rock, stop rotating the bolt and adjust the fastening nut to the lower side of the bolt so that the bolt becomes the main load-bearing structure of the device.

10. The method for tightening steel arch frames in TBM tunnels as described in claim 9, characterized in that: The process also includes a splicing step: using a steel arch splicing mechanism to grab two adjacent steel arch frames and perform a butt joint splicing operation; this is accomplished by actuators connected to the ends of two symmetrically arranged splicing arms in the splicing mechanism; the splicing arm rotates to the working position via a base rotation joint, and then the actuator's posture is adjusted by the linkage of the middle rotation joint and the end rotation joint; the actuator clamps the steel arch frame from above via its upper jaw, and simultaneously supports it from below via its lower jaw, to stably grab and guide the steel arch frame to complete the splicing.

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