Starting block unbalanced load monitoring device in continuous beam bridge cantilever construction

Abstract

The utility model relates to the technical field of bridge engineering construction, in particular to a plurality of groups of initial block unbalanced load monitoring devices in continuous beam bridge cantilever construction, which are symmetrically arranged on two sides of a bridge pier along the span direction of a bridge respectively. The starting block unbalance load monitoring device comprises a steel beam and a dynamometer, the steel beam straightly penetrates through the starting block, the two ends of the steel beam are a measuring end and a pre-buried end respectively, the measuring end penetrates through the dynamometer and is fixed to the top face of the starting block, and the pre-buried end is fixed to a bearing platform of a pier or the interior of a pier body. The arrangement positions of the dynamometer and the steel beam not only do not interfere with temporary consolidation construction, but also facilitate overhaul of the dynamometer and the steel beam, the dynamometer monitors the load in the cantilever construction of the continuous beam bridge in real time by measuring the stress change of the steel beam, and the dead weight of the beam bridge does not affect the monitoring result.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering construction technology, and in particular to a device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge. Background Technology

[0002] When using cantilever construction with formwork for prestressed concrete continuous beam bridges, temporary consolidation is required between the main beam of block 0 (i.e., the starting block) and the pier to ensure that tilting, collapse, or other safety accidents will not occur due to unbalanced loads during the cantilever construction process. The temporary consolidation is only reinforced with a certain amount of steel based on theoretical calculations of tensile and tensile strength. However, due to the complexity of the construction process, special situations may arise, such as asynchronous movement of the formwork on both sides of the pier, asynchronous concrete pouring, and asymmetrical temporary load application. If the unbalanced load exceeds the limit, it may cause safety and property damage. Therefore, monitoring the unbalanced load at block 0 is extremely important.

[0003] In existing technologies, unbalanced load monitoring devices for the starting block are typically installed between the pier and the starting block using gravity sensors. However, the locations of the gravity sensors and temporary consolidation overlap, thus affecting the proper installation of the temporary consolidation. Furthermore, if the gravity sensors are damaged or show abnormal data, their inspection and maintenance are quite difficult. In addition, when gravity sensors are installed between the pier and the starting block, the loads monitored by these sensors include the self-weight loads of the main beams on both sides. Since the self-weight load itself is large, the unbalanced load accounts for a relatively small proportion of the self-weight load, making the analysis of the results very complex and inaccurate.

[0004] Therefore, it is necessary to propose a monitoring device for the unbalanced load of the starting block in the cantilever construction of continuous beam bridges to solve or at least alleviate the above-mentioned defects. Utility Model Content

[0005] The main purpose of this utility model is to provide a monitoring device for the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge, so as to solve the technical problems of the temporary consolidation setting of the gravity sensor position interference and the difficulty of gravity sensor maintenance in the prior art.

[0006] To achieve the above objectives, this utility model provides a starting block unbalanced load monitoring device for cantilever construction of continuous beam bridges. The starting block unbalanced load monitoring device consists of multiple sets, which are symmetrically arranged on both sides of the bridge pier along the bridge span direction. The starting block unbalanced load monitoring device includes a steel strand and a force gauge. The steel strand is taut and passes through the starting block. The two ends of the steel strand are a measuring end and a pre-embedded end, respectively. The measuring end passes through the force gauge and is fixed to the top surface of the starting block. The pre-embedded end is fixed to the pier cap or inside the pier body.

[0007] Preferably, it also includes anchor bolts, and the measuring end and the pre-embedded end are fixed by anchor bolts.

[0008] Preferably, it further includes a support beam, which is fixed below the force gauge at the measuring end.

[0009] More preferably, anchor plates are provided between the anchor bolt and the force gauge, between the anchor bolt and the bridge pier, and between the force gauge and the support beam.

[0010] More preferably, it also includes a wedge block, which is fixed between the support beam and the anchor plate.

[0011] Preferably, the steel strand is divided into two sections, one section with the pre-embedded end fixed inside the pier or the foundation, and the other section fixed to the starting block, with the two sections of steel strand fixedly connected with their axes aligned.

[0012] More preferably, the two steel strands are connected by a sleeve, and the two steel strands inside the sleeve have the same length.

[0013] Preferably, an anchoring zone is provided above the pre-embedded end, and a steel mesh is fixed inside the anchoring zone.

[0014] Furthermore, it also includes a tensioning device, which includes a tensioning bolt, a jack, and a reaction beam. The tensioning device is fixed above the force gauge via the reaction beam, and the steel strand is connected to the jack and the tensioning bolt in sequence.

[0015] More preferably, the steel strand is a precision-rolled threaded steel bar.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] In this invention, the pre-embedded end of the steel strand is fixed to the bridge pier, and the measuring end is fixed to the top of the starting block, and symmetrically arranged on both sides of the bridge pier. The placement of the force gauge and the steel strand not only does not interfere with the construction of the temporary consolidation, but also facilitates the maintenance of the force gauge and the steel strand. Moreover, the symmetrically arranged steel strands can provide tension to offset unbalanced loads, assisting the temporary consolidation in resisting unbalanced loads and improving the stability of cantilever construction. The force gauge monitors the load in the cantilever construction of the continuous beam bridge in real time by measuring the stress change of the steel strand. The self-weight of the beam bridge does not affect the monitoring results, reducing the requirements of the force gauge, simplifying the analysis process of the monitoring results, and improving the accuracy of the monitoring results. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram showing the location of temporary consolidation in the prior art;

[0020] Figure 2 This is a schematic diagram of the overall structure in one embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the internal structure of the pre-embedded end in one embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the tensioning device in one embodiment of the present invention;

[0023] Figure 5 This is a side cross-sectional view of one embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the steel strand connection of a high-pier beam bridge in one embodiment of the present invention.

[0025] The purpose, features, and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0026] Explanation of icon numbers:

[0027] 1. Temporary consolidation; 2. Force gauge; 3. Steel strand; 4. Anchor bolt; 5. Anchor plate; 6. Support beam; 7. Sleeve; 8. Wedge block; 9. Pier cap; 10. Pier body; 11. Data acquisition module; 12. Wireless transceiver module; 13. Power module; 14. Steel mesh; 15. Jack; 16. Tensioning bolt; 17. Reaction bearing beam; 100. Starting block. Detailed Implementation

[0028] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0031] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0032] The large-span variable cross-section concrete continuous beam bridge adopts cantilever segmental construction with hanging formwork. The construction steps are to move the hanging formwork forward, install steel bars, pour concrete, and tension steel strands, and repeat this cycle until the side spans and middle spans are closed. During the cantilever construction process, unbalanced loads will be generated due to asynchronous construction on both sides or inconsistent loads on both sides.

[0033] To resist unbalanced loads during construction, a temporary consolidation 1 needs to be installed between the pier and the starting block 100. This is achieved by installing concrete strip supports at the edge of the pier top, symmetrically arranged front, back, left, and right, with HRB400, φ32mm steel bars, 110 bars per support. The steel bars are arranged in multiple rows with a spacing of 15cm, interspersed with the steel bars of the pier body 10, and φ12mm stirrups are installed at a spacing of 15cm. Based on the actual site conditions, it is considered that the steel bars of the temporary consolidation 1 will use sleeves 7 to achieve a "permanent-temporary connection" of the vertical main reinforcement of the pier body 10, and the remaining steel bars will be anchored into the pier and the starting block 100 for 1m. During pouring, a layer of asphalt felt will be laid on the top of the pier, and after pouring, another layer of asphalt felt will be laid on the top of the temporary support to prevent the temporary support from adhering to the starting block 100 and the pier body 10; the concrete support will be removed during closure.

[0034] Please see the appendix Figure 1-5 This embodiment takes the cantilever construction of a low-pier continuous beam bridge as an example. This embodiment provides a monitoring device for the unbalanced load of the starting block during the cantilever construction of a continuous beam bridge. Multiple sets of the starting block unbalanced load monitoring device are symmetrically arranged on both sides of the pier along the bridge span direction. The starting block unbalanced load monitoring device includes steel strands 3 and force gauges 2. The steel strands 3 are taut and pass through the starting block 100, with a measuring end and a pre-embedded end at both ends. The measuring end passes through the force gauge 2 and is fixed to the top surface of the starting block 100, while the pre-embedded end is fixed inside the pier cap 9 or pier body 10. The placement of the force gauges 2 and steel strands 3 not only avoids interfering with the construction of the temporary consolidation 1 but also facilitates the maintenance of the force gauges 2 and steel strands 3. Furthermore, the symmetrically arranged steel strands 3 can provide tension to offset unbalanced loads, improving the stability of the cantilever construction.

[0035] In this embodiment, the force gauge 2 monitors the load during the cantilever construction of a continuous beam bridge in real time by measuring the stress changes of the steel strands 3. The self-weight of the beam bridge does not affect the monitoring results, reducing the requirements for the force gauge 2, simplifying the analysis process of the monitoring results, and improving the accuracy of the monitoring results. By summarizing the variation law of unbalanced loads and analyzing the causes of unbalanced loads, a reference can be provided for the design and construction of similar beam bridges. In this embodiment, the steel strands 3 are made of high-strength, readily available precision-rolled threaded steel. The usage time of this embodiment lasts throughout the entire bridge construction, and installation and disassembly are simple. Furthermore, the force gauge 2 and the precision-rolled threaded steel can be reused, resulting in low construction costs and high efficiency. This can effectively avoid safety accidents caused by unbalanced loads during construction, reducing safety risks and property losses.

[0036] In one embodiment, preferably, this embodiment further includes anchor bolts 4, which fix the measuring end and the pre-embedded end. Anchor bolts 4 facilitate the installation and disassembly of the device. Double anchor bolts can be used to improve the connection stability between the steel strand 3 and the force gauge 2.

[0037] In one preferred embodiment, the system further includes a support beam 6, which is fixed below the force gauge 2 at the measuring end. In this embodiment, the support beam 6 is made of double-section I-beams, which increases the contact area between the force gauge 2 and the bridge deck, thereby ensuring that large-area cracks do not appear in the localized areas of the bridge deck where the initial block 100 is subjected to stress, thus affecting the bridge deck quality. Since unbalanced loads are often large, to ensure that the support beam 6 can stably support the force gauge 2, the double-section I-beams are also welded with reinforcing ribs to enhance the load-bearing capacity of the support beam 6.

[0038] In this embodiment, as a further preferred embodiment, anchor plates 5 are provided between the anchor bolt 4 and the force gauge 2, between the anchor bolt 4 and the bridge pier, and between the force gauge 2 and the support beam 6. When the measuring end of the precision-rolled threaded steel is anchored on the starting block 100, the bridge deck needs to be leveled in advance using steel plates or concrete to ensure that the precision-rolled threaded steel is axially stressed. An anchoring zone is also provided above the pre-embedded end, and a steel mesh 14 is fixed inside the anchoring zone. The anchoring of the precision-rolled threaded steel requires high pull-out resistance, so the anchoring depth of the pre-embedded end of the precision-rolled threaded steel is required to be no less than 1.5 meters as the anchoring zone. Not only are double anchor bolts used for anchoring, but the anchor plates 5 should also be set as double layers. At the same time, the anchoring zone is further reinforced by setting the steel mesh 14, ultimately ensuring the overall strength of the pre-embedded end anchoring zone and improving the stability of this embodiment.

[0039] In one embodiment, the steel strand 3 is divided into two sections. One section, containing the pre-embedded end, is fixed inside the pier cap 9 or the pier body 10, while the other section is fixed to the starting block 100. The two sections of the steel strand 3 are fixedly connected with their axes aligned. The two sections of the steel strand 3 are connected by a sleeve 7, with the two sections of the steel strand 3 having the same length inside the sleeve 7. Connecting the steel strand 3 in sections facilitates construction. During pier construction, the shorter length of the pre-embedded end section prevents interference with the construction of the starting block 100. When fixing the steel strand 3 at the measuring end, the position should be perpendicular to the location of the pre-embedded end. The connection of the steel strand 3 through the sleeve 7 ensures that the axes of the steel strand 3 are aligned, thereby ensuring that the steel strand 3 itself will not bear shear force during use and preventing the steel strand 3 from breaking.

[0040] In one embodiment, a tensioning device is further included, comprising a tensioning bolt 16, a jack 15, and a reaction beam 17. The tensioning device is fixed above the force gauge 2 via the reaction beam 17. The steel strands 3 are sequentially connected to the jack 15 and the tensioning bolt 16. Before formal use in this embodiment, the jack 15 provides a pretension of 10% to 20% deformation to the steel strands 3, ensuring that the fine-rolled threaded steel is in a taut state. During tensioning, the tension force of each steel strand 3 should be kept as consistent as possible, and the pretension value of each fine-rolled threaded steel should be recorded for subsequent analysis of load changes.

[0041] like Figure 6 As shown, in another embodiment, the cantilever construction of a high-pier continuous beam bridge also includes a wedge block 8, which is fixed between the support beam 6 and the anchor plate 5. The cantilever construction of the high-pier continuous beam bridge involves setting the pre-embedded end in the pier body 10, thereby reducing the length of the threaded steel bar and avoiding instability due to excessive length. The wedge block 8 is used to adjust the angle of the threaded steel bar, preventing it from experiencing shear force during use and further improving stability.

[0042] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A device for monitoring the unbalanced load of the starting block during cantilever construction of a continuous beam bridge, characterized in that, The unbalanced load monitoring device for the starting block consists of multiple sets, which are symmetrically arranged on both sides of the pier along the bridge span direction. The unbalanced load monitoring device for the starting block includes a steel strand and a force gauge. The steel strand is taut and runs through the starting block. The two ends of the steel strand are a measuring end and a pre-embedded end, respectively. The measuring end passes through the force gauge and is fixed to the top surface of the starting block. The pre-embedded end is fixed to the pier cap or inside the pier body.

2. The device for monitoring the unbalanced load of the starting block during cantilever construction of a continuous beam bridge according to claim 1, characterized in that, It also includes anchor bolts, and the measuring end and the pre-embedded end are fixed by anchor bolts.

3. The device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge according to claim 2, characterized in that, It also includes a support beam, which is fixed below the force gauge at the measuring end.

4. The device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge according to claim 3, characterized in that, Anchor plates are provided between the anchor bolts and the force gauge, between the anchor bolts and the bridge pier, and between the force gauge and the support beam.

5. The device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge according to claim 4, characterized in that, It also includes a wedge block, which is fixed between the support beam and the anchor plate.

6. The device for monitoring the unbalanced load of the starting block during cantilever construction of a continuous beam bridge according to claim 1, characterized in that, The steel strand is divided into two sections. One section, where the pre-embedded end is located, is fixed inside the pier or the foundation, and the other section is fixed to the starting block. The two sections of steel strand are fixedly connected with their axes aligned.

7. The device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge according to claim 6, characterized in that, The two steel strands are connected by a sleeve, and the two steel strands inside the sleeve are of the same length.

8. The device for monitoring the unbalanced load of the starting block during cantilever construction of a continuous beam bridge according to claim 1, characterized in that, An anchoring zone is also provided above the pre-embedded end, and a steel mesh is fixed inside the anchoring zone.

9. The device for monitoring the unbalanced load of the starting block during cantilever construction of a continuous beam bridge according to claim 1, characterized in that, It also includes a tensioning device, which includes a tensioning bolt, a jack, and a reaction beam. The tensioning device is fixed above the force gauge by the reaction beam, and the steel strand is connected to the jack and the tensioning bolt in sequence.

10. The device for monitoring the unbalanced load of the starting block in the cantilever construction of a continuous beam bridge according to any one of claims 1-9, characterized in that, The steel strand is a precision-rolled threaded steel bar.

Images