Methods for beam assembly in confined spaces and integrated piers

Abstract

This invention discloses a method for assembling beams in confined spaces, comprising: S100: defining an assembly area within the confined space and arranging a jacking support system along the jacking direction of the beam within the assembly area; S200: within the assembly area, using lifting equipment to longitudinally fix and connect guide beams and multiple box girder segments sequentially to form an initial beam segment; activating the jacking equipment to push the initial beam segment forward out of the confined space; subsequently assembling subsequent box girder segments again in the assembly area and continuing jacking until all box girder segments are assembled and jacked to a predetermined position; S300: after all box girder segments are in place and the beam is fixed in place, hoisting cross bracing and cantilever arms to the designed positions on the sides and tops of the box girder segments and fixing them to the box girder segments. This invention is suitable for beam assembly and jacking in confined spaces, and can conveniently complete the assembly of beam components, jacking along the designed line, and final installation without modifying the existing structure.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering construction technology, and in particular to a method for assembling beams in confined spaces and an integrated pier. Background Technology

[0002] In bridge engineering, especially in the construction of bridges spanning canyons, rivers, or existing transportation routes, the incremental launching method is an important bridge erection method. This method typically involves assembling bridge beam segments one by one behind the abutments or on a pre-designated assembly platform, and then using hydraulic equipment to push the entire beam forward until it is gradually in place. This method causes minimal disruption to navigation or traffic below the bridge and reduces the amount of work done at heights, thus finding application under specific terrain conditions.

[0003] However, traditional integral launching construction methods face challenges when bridge construction involves connections to confined spaces such as tunnels. The lateral space inside a tunnel is typically strictly limited by the tunnel's width, making it difficult to deploy lifting equipment requiring a large operating radius. More significantly, traditional methods require the integral assembly of the beam, including the box girder, cross bracing, and cantilever, before launching. The hoisting and welding of lateral components such as cross bracing and cantilever can easily interfere with the tunnel walls within the narrow space, making assembly difficult. Widening the tunnel or excavating new assembly chambers would significantly increase project costs and time.

[0004] Furthermore, to adapt to terrain or route requirements, bridge designs often incorporate horizontal curves. During incremental launching on curved sections, the varying travel distances of different points along the arc can easily lead to unfavorable lateral forces between the beam and the launching track. Insufficient synchronization control precision at each launching point may cause the beam's axis to deviate from the design trajectory or even twist, increasing the difficulty of alignment control and correction work during construction, and placing higher demands on construction control.

[0005] Therefore, it is necessary to design a beam assembly and jacking method suitable for implementation in confined spaces, so as to more efficiently complete the assembly of beam components, jacking along the design line, and final installation without modifying the existing structure. Summary of the Invention

[0006] To address the above-mentioned issues and overcome the shortcomings of existing technologies, this invention provides a method for assembling beams in confined spaces. Based on the same inventive concept, this invention also provides construction equipment for this method. This method for assembling beams in confined spaces and the integrated support pier are suitable for beam assembly and jacking within confined spaces, enabling more efficient completion of beam component assembly, jacking along the designed alignment, and final installation without modifying existing structures.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a method for assembling beams in a confined space, comprising the following steps:

[0009] S100: Define an assembly area within a confined space, and install a jacking support system within the assembly area along the jacking direction of the beam;

[0010] S200: In the assembly area, lifting equipment is used to longitudinally fix and connect the guide beam and multiple box sections in sequence to form an initial beam section; the jacking equipment is started to push the initial beam section forward out of the confined space; then the subsequent box sections are assembled again in the assembly area, and the jacking continues until all the box sections are assembled and pushed to the predetermined position;

[0011] S300: After all the box sections are in place and the beams are fixed, the cross bracing and cantilever arms are hoisted to the designed positions on the sides and top of the box sections and fixedly connected to the box sections.

[0012] Furthermore, in step S100, the confined space is inside the tunnel; the assembly area is defined inside the tunnel, and the minimum distance between its boundary and the tunnel sidewall is not less than 0.5 meters.

[0013] Furthermore, in step S200, the stroke distance of each jacking is configured such that the newly assembled chamber section can fully enter the support range of the jacking support system.

[0014] Furthermore, in step S200, the jacking process is a jacking along a plane curve; during the jacking process, the axial deviation of the beam is monitored in real time, and the position of the beam is adjusted by a guide device and a correction jack that are movably connected to the side of the integrated support; after each set number of jacking strokes is completed, an active lateral correction operation is performed.

[0015] Furthermore, in step S200, the stroke synchronization error of each jacking point is controlled to not exceed 0.0004 times the length of a single chamber section.

[0016] Furthermore, in step S200, the beam is pushed across the canyon terrain, and the pushing support system includes multiple integrated piers arranged on both sides and in the middle of the canyon; the top of the integrated piers is integrated with a slide for supporting the sliding of the beam during the pushing stage, and a beam dropping mechanism for supporting the beam and controlling its synchronous descent during the final beam dropping stage.

[0017] Furthermore, step S200 also includes:

[0018] S210: After all the box girder sections are pushed into place, the beam-dropping mechanism on the integrated support is activated, and the equivalent beam-dropping method is used to synchronously lower all the box girder sections to the design elevation.

[0019] Furthermore, the beam lowering mechanism includes multiple vertically installed beam lowering jacks; during the beam lowering process, the jacking synchronization error of each beam lowering jack on the same integrated support is controlled to not exceed 0.0002 times the length of a single box section.

[0020] Furthermore, in step S300, the cross bracing and cantilever arm are fixedly connected to the chamber section by welding; after welding is completed, the weld is subjected to non-destructive testing, which includes at least ultrasonic testing and magnetic particle testing.

[0021] Based on the same inventive concept, the present invention also provides an integrated support pier for the above-mentioned beam assembly method in confined space, comprising:

[0022] The pile foundation, pile cap, and steel columns are arranged sequentially from bottom to top.

[0023] The top of the steel column is fixedly installed with a jacking slide;

[0024] The top of the steel column, below or to the side of the jacking slide, is also equipped with a beam lowering mechanism; the beam lowering mechanism is configured to be in a retracted or non-pressure-bearing state during the jacking stage, and to be activated after the beam is jacked into place, so as to synchronously lift the beam from the jacking slide and finally lower it to the design elevation.

[0025] The present invention has at least the following advantages or beneficial effects:

[0026] This invention employs the steps of designating a dedicated assembly area and deploying a jacking support system within a confined space. This step provides a stable working surface and force transmission path for subsequent component assembly and jacking operations. It also adopts a process arrangement that combines longitudinal assembly of the box girder section, jacking and transverse connection, and post-installation of the cantilever arm. This arrangement reduces the lateral space requirements for assembly operations. Overall, this invention provides a feasible operational method for the assembly and erection of beams in environments with limited lateral dimensions, such as tunnels.

[0027] This invention employs a method of real-time monitoring of axial deviation during curved jacking and adjustment using a guiding device and corrective jacks. This method allows for dynamic control of the beam's travel direction. It also employs an active lateral correction operation performed according to a set jacking stroke, which can periodically correct accumulated positional deviations. Overall, this invention enables management of the beam's alignment during curved jacking, supporting its movement along the designed plane trajectory.

[0028] This invention employs a technical requirement that the synchronization error of each jacking point's stroke should not exceed 0.002 times the length of the box girder section. This technical requirement allows for a quantitative constraint on the synchronization accuracy of the jacking equipment. Overall, this invention can reduce the risk of excessive local stress on the beam or obstruction due to asynchrony by controlling the synchronization of multi-point jacking.

[0029] This invention employs a technical requirement that the synchronous lifting error of each beam-lowering jack on the same integrated support pier should not exceed 0.001 times the length of the box girder section. This technical requirement allows for quantitative control of the smoothness of the beam-lowering process. Overall, this invention, by controlling the synchronous accuracy of beam lowering, promotes coordinated displacement of each support point during the beam's descent, which is beneficial for ensuring the structural alignment and stress state after beam lowering. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 Flowchart of beam assembly method in confined space;

[0032] Figure 2 This is a schematic diagram of the overall construction layout;

[0033] Figure 3 This is a schematic diagram of the construction layout inside the tunnel;

[0034] Figure 4 This is a schematic diagram of the first state of the beam assembly method step S200 in a confined space.

[0035] Figure 5 This is a schematic diagram of the second state of step S200 in the beam assembly method under confined space.

[0036] Figure 6 This is a schematic diagram of the third state of step S200 in the beam assembly method under confined space.

[0037] Figure 7 This is a schematic diagram of the fourth state of the beam assembly method in a confined space, step S200.

[0038] Figure 8 This is a schematic diagram of an integrated pier structure;

[0039] Figure 9 This is a right view of the integrated pier structure.

[0040] Figure label:

[0041] 1-Tunnel; 2-Double hook gantry crane; 3-Box section; 4-Guide beam; 5-Integrated support pier; 51-Pile foundation; 52-Pile cap; 53-Steel column; 54-Pushing slide; 55-Beam dropping mechanism. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0044] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0045] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are only used to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any part or element in this invention. They should not be construed as limitations on this invention.

[0046] In this invention, terms such as "fixed," "connected," and "linked" should be interpreted broadly, indicating that the connection can be fixed, integral, or detachable; it can be a direct connection or an indirect connection through an intermediate medium. For researchers or technicians in the field, the specific meaning of the above terms in this invention can be determined according to the specific circumstances, and they should not be construed as limitations on this invention.

[0047] The embodiments of the present invention will be described in detail below.

[0048] This invention discloses a method for assembling beams in confined spaces. It is suitable for beam assembly and jacking within confined spaces, enabling more efficient completion of beam component assembly, jacking along the designed alignment, and final installation without modifying existing structures.

[0049] Figure 1 Flowchart of beam assembly method in confined space; Figure 2 This is a schematic diagram of the overall construction layout; Figure 3This is a schematic diagram of the construction layout inside the tunnel; Figure 4 This is a schematic diagram of the first state of the beam assembly method step S200 in a confined space. Figure 5 This is a schematic diagram of the second state of step S200 in the beam assembly method under confined space. Figure 6 This is a schematic diagram of the third state of step S200 in the beam assembly method under confined space. Figure 7 This is a schematic diagram of the fourth state of the beam assembly method in a confined space, step S200.

[0050] First, step S100 is executed: a dedicated assembly area is designated within the confined space inside tunnel 1. This assembly area provides a centralized and orderly work site for the on-site assembly of the beam components. The assembly area is located within tunnel 1, and the minimum distance between its boundary and the sidewall of tunnel 1 is set at 0.7 meters. This distance ensures sufficient space for the trolley traveling mechanism, lifting tools, and assembly operations of lifting equipment such as the double-hook gantry crane 2, preventing interference with the tunnel lining and ensuring operational safety. In other embodiments, considering the size and safety specifications of different equipment models, this minimum distance can also be 0.5 meters, 0.6 meters, or 0.8 meters. Within this assembly area, a jacking support system is installed along the predetermined jacking direction of the beam. This system constructs a continuous and stable force transmission path extending from the assembly starting point to the target position, providing a reliable reaction foundation and intermediate support for subsequent jacking operations.

[0051] Next, the core "simultaneous assembly and jacking" operation of step S200 is performed. Within the assembly area, a double-hook gantry crane 2 with matching lifting capacity is used to hoist the guide beam 4 and the first box section 3 into position and perform longitudinal fixing (e.g., Figure 4 (As shown). In this embodiment, the guide beam 4 is 52 meters long. The 6-meter section connecting it to the steel beam is designed as a box-type structure to provide sufficient local stiffness, while the remaining portion is an I-shaped structure to reduce its weight. The guide beam 4 is horizontally connected using a steel pipe truss structure. The function of the guide beam 4 is to guide the front end of the beam smoothly across the gap of the integrated support pier and effectively reduce the downward deflection of the cantilever end during the jacking process. The first box section 3 is longitudinally fixed to the guide beam 4 using high-strength bolts, thus forming an initial beam segment. The walking synchronous jacking equipment is started to push the initial beam segment forward to the tunnel entrance. Subsequently, the second box section 3 is assembled again in the assembly area and longitudinally fixed to the tail of the initial beam segment that has been pushed out of the tunnel entrance using welding or high-strength bolts. Then, jacking continues (e.g., ...). Figure 5 (As shown). This cycle of "assembling one section, pushing one section" continues until all the box-type sections 3 are assembled and pushed to the predetermined position on the opposite bank of the canyon (as shown). Figure 6(As shown). In this embodiment, the box girder segment 3 is a prefabricated steel box girder segment in the factory, and its length is usually 10 meters. The stroke distance of each jacking is specifically configured to be 1.5 times the length of the box girder segment 3, that is, 15 meters. The purpose of this distance is to ensure that the newly assembled box girder segment 3 can completely enter the support range of the next integrated support pier in the jacking support system, so that the weight of the newly assembled segment can be borne by the new integrated support pier in a timely manner, and the bending moment distribution of the beam during the jacking process can be optimized. In other embodiments, depending on the different modular lengths of the box girder segment 3 in actual engineering, this stroke distance can also be configured to 15 meters, 20 meters or 25 meters.

[0052] The jacking process is a planar circular curve jacking along the design radius. During the jacking process, the axial deviation of the beam's centerline is monitored in real time using measuring equipment such as a total station and GPS receiver. The beam's position is dynamically fine-tuned by a guide device and a correction jack that are hinged or sliding on the side of the integrated support 5. The guide device is typically a rigid guide frame welded from steel sections, which provides a force application point for the correction jacks and limits excessive lateral displacement of the beam. The correction jacks can be arranged in a single-sided jacking or double-sided jacking configuration. Every 10 jacking strokes, the system automatically performs an active lateral correction operation to systematically correct the accumulated alignment deviation. In this embodiment, the synchronization error of the stroke at each jacking point is controlled to not exceed 0.0004 times the length of a single box section 3, that is, for a standard segment of 10 meters, the synchronization error is not greater than 4 millimeters. The purpose of this precision requirement is to reduce the torsional internal force of the beam and the additional sliding friction resistance caused by the asynchronous movement of each point by accurately controlling the coordinated movement of multiple points. In other embodiments, depending on the curve radius and the performance of the jacking equipment, the synchronization error control value can also be set to 0.0002 times or 0.0025 times the length of the box section 3.

[0053] The beam is jacked across the canyon terrain, and the jacking support system includes multiple integrated support piers 5 deployed on both sides and in the middle of the canyon. The top of each integrated support pier 5 is integrated with a slide for supporting the sliding of the beam during the jacking stage. The surface of the slide is covered with stainless steel plates or inlaid with polytetrafluoroethylene sliding plates to reduce the coefficient of friction; and a beam lowering mechanism for supporting the beam and controlling its synchronous descent during the final beam lowering stage.

[0054] After all box girder sections 3 have been pushed into place, proceed to step S210: activate the beam-lowering mechanism on all integrated piers 5, and use the equivalent beam-lowering method to synchronously lower all box girder sections 3 to the design elevation (e.g., Figure 7(As shown). The beam lowering mechanism includes multiple vertically installed 500-ton hydraulic beam lowering jacks. The cylinders of the beam lowering jacks are fixed to the load-bearing crossbeams of the integrated support pier 5 via flanges. During the beam lowering process, a PLC-based central control system controls the jacking synchronization error of each beam lowering jack on the same integrated support pier 5 to not exceed 0.0002 times the length of a single box section 3, that is, for a 10-meter segment, the synchronization error is not greater than 2 millimeters. The function of this high-precision control is to ensure that the beam achieves a smooth conversion of the support reaction force in a stable state without additional internal forces. In other embodiments, the rated load of the beam lowering jacks can also be 400 tons or 600 tons, and the synchronization error control value can also be 0.0001 times or 0.00015 times the length of the box section 3.

[0055] Finally, step S300 is executed: After all the box girder sections 3 are in place and the beams are fixed, the cross bracing and cantilever arms are hoisted to their designed positions on the sides and top of the box girder sections 3 using a small gantry crane or truck crane. The cross bracing and cantilever arms are also prefabricated components, and their connection to the pre-reserved interfaces on the box girder sections 3 is achieved through welding. Gas shielded welding is used, with the welding wire material matching the base material. During welding, the interpass temperature must be controlled, and welding must be performed according to a predetermined welding sequence to reduce deformation. After welding, non-destructive testing (NDT) is performed on the weld. In this embodiment, the NDT includes at least ultrasonic testing (UT) to examine the internal quality of the weld and magnetic particle testing (MT) to examine surface and near-surface opening defects in the weld; 100% ultrasonic testing is required for full penetration welds. In other embodiments, depending on design requirements and material characteristics, NDT may also include radiographic testing (RT) or penetrant testing (PT).

[0056] Based on the same inventive concept, the present invention also provides an integrated support 5 for the above-mentioned beam assembly method in confined space.

[0057] Figure 8 This is a schematic diagram of the integrated support pier 5 structure; Figure 9 This is a right view of the integrated pier 5 structure.

[0058] The integrated support pier 5 includes a pile foundation 51, a pile cap 52, and a steel column 53 arranged sequentially from bottom to top.

[0059] The function of pile foundation 51 is to safely transfer all vertical and horizontal loads borne by the integrated pier to the deep stable foundation. It is usually made by drilling holes with a rotary drilling rig and pouring in C30 or higher grade concrete. The pile diameter can be designed to be 1.2 meters or 1.5 meters according to the bearing capacity requirements.

[0060] The function of the pile cap 52 is to connect multiple pile foundations 51 to the upper steel column 53, and to distribute and redistribute the load. It is typically a reinforced concrete structure with on-site steel reinforcement binding, formwork erection, and pouring, with dimensions such as 3 meters × 3 meters × 1.5 meters. The function of the steel column 53 is to provide the required support height and effectively transfer the concentrated load from the top slide rail and beam lowering mechanism to the lower pile cap 52. It is made of steel, manufactured by rolling sheet metal or welding profiles. In this embodiment, the cross-section is a circular steel pipe with a diameter of 800 mm. In other embodiments, the cross-section of the steel column 53 can also be a square steel pipe with a side length of 600 mm, or a lattice column composed of H-beams, angle steel, etc., to meet different stiffness and stability requirements.

[0061] The top of the steel column 53 is fixedly installed with a jacking slide 54 by high-strength bolts or bevel penetration welding. The function of the jacking slide 54 is to provide a flat, strong and low-friction sliding track for the beam during the jacking stage. Its main structure is a welded box girder or I-beam. The surface of the top bearing plate is usually inlaid with a polytetrafluoroethylene sliding plate or a stainless steel plate. The thickness of the sliding plate can be 10-20 mm.

[0062] At the top of the steel column 53, on the side of the jacking slide 54 (symmetrically arranged on both sides along the length of the slide in this embodiment), a beam lowering mechanism 55 is integrated and installed via a high-strength flange or welding. In other embodiments, based on stress analysis and spatial layout, the beam lowering mechanism 55 can also be arranged directly below the jacking slide 54, and the jacking operation is carried out through the clearance holes reserved on the jacking slide 54. The beam lowering mechanism 55 is configured such that: during the jacking stage, its piston rod is in a fully retracted state, and a certain gap is maintained between the top and the bottom surface of the slide or the bottom of the beam, so that it is in a non-compression state, thereby not interfering with the free sliding of the beam; after the beam is jacked into place, the control system issues a command, and all beam lowering mechanisms 55 start synchronously, lifting the beam smoothly and synchronously from the jacking slide 54, so that the bottom surface of the beam is completely separated from the top surface of the slide, and then, according to a predetermined procedure, the beam is lowered synchronously and in stages to the design elevation of the permanent support, and finally the beam lowering is completed. This design, which integrates the functions of jacking and beam lowering into a single integrated pier structure, avoids the high-risk and low-efficiency process of dismantling temporary piers and erecting dedicated beam lowering supports in complex terrains such as canyons.

[0063] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for assembling beams in a confined space, characterized in that, Includes the following steps: S100: Define an assembly area within a confined space, and install a jacking support system within the assembly area along the jacking direction of the beam; S200: In the assembly area, lifting equipment is used to longitudinally fix and connect the guide beam and multiple box sections in sequence to form an initial beam section; the jacking equipment is started to push the initial beam section forward out of the confined space; then the subsequent box sections are assembled again in the assembly area, and the jacking continues until all the box sections are assembled and pushed to the predetermined position; S300: After all the box sections are in place and the beams are fixed, the cross bracing and cantilever arms are hoisted to the designed positions on the sides and top of the box sections and fixedly connected to the box sections.

2. The method for assembling a beam in a confined space according to claim 1, characterized in that, In step S100, the confined space is inside the tunnel; the assembly area is defined inside the tunnel, and the minimum distance between its boundary and the tunnel sidewall is not less than 0.5 meters.

3. The method for assembling a beam in a confined space according to claim 1, characterized in that, In step S200, the stroke distance of each jacking is configured such that the newly assembled compartment section can fully enter the support range of the jacking support system.

4. The method for assembling a beam in a confined space according to claim 1, characterized in that, In step S200, the jacking process is a jacking along a plane curve; during the jacking process, the axial deviation of the beam is monitored in real time, and the position of the beam is adjusted by a guide device and a correction jack that are movably connected to the side of the integrated support; after each set number of jacking strokes is completed, an active lateral correction operation is performed.

5. The method for assembling a beam in a confined space according to claim 4, characterized in that, In step S200, the stroke synchronization error of each jacking point is controlled to not exceed 0.0004 times the length of a single chamber section.

6. The method for assembling a beam in a confined space according to claim 1, characterized in that, In step S200, the beam is pushed across the canyon terrain. The pushing support system includes multiple integrated piers arranged on both sides and in the middle of the canyon. The top of the integrated piers is integrated with a slide for supporting the sliding of the beam during the pushing stage, and a beam dropping mechanism for supporting the beam and controlling its synchronous descent during the final beam dropping stage.

7. The method for assembling a beam in a confined space according to claim 6, characterized in that, Step S200 further includes: S210: After all the box girder sections are pushed into place, the beam-dropping mechanism on the integrated support is activated, and the equivalent beam-dropping method is used to synchronously lower all the box girder sections to the design elevation.

8. The method for assembling a beam in a confined space according to claim 7, characterized in that, The beam lowering mechanism includes multiple vertically installed beam lowering jacks; during the beam lowering process, the jacking synchronization error of each beam lowering jack on the same integrated support is controlled to not exceed 0.0002 times the length of a single box section.

9. The method for assembling a beam in a confined space according to claim 6, characterized in that, In step S300, the cross bracing and cantilever arm are fixedly connected to the chamber section by welding; after welding is completed, the weld is subjected to non-destructive testing, which includes at least ultrasonic testing and magnetic particle testing.

10. An integrated support pier for the beam assembly method in a confined space according to any one of claims 1 to 9, characterized in that, include: The pile foundation (51), pile cap (52), and steel column (53) are arranged sequentially from bottom to top. The top of the steel column (53) is fixedly installed with a jacking slide (54); The top of the steel column (53), below or to the side of the jacking slide (54), is also equipped with a beam dropping mechanism (55); the beam dropping mechanism (55) is configured to be in a retracted or non-pressure state during the jacking stage, and to be activated after the beam is jacked into place, so as to simultaneously lift the beam from the jacking slide (54) and finally lower it to the design elevation.

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