Synchronous pre-pressing method and device for No.0 block support

Abstract

The invention belongs to the technical field of bridge construction, and discloses a synchronous pre-pressing method and device for a No.0 block support. The synchronous pre-pressing method for the No.0 block support comprises the steps that before bearing platform construction, pre-buried point positions on a bearing platform and pre-pressing point positions on a distribution beam are determined; when a bearing platform is constructed, a part of lifting lug assemblies are pre-buried on the bearing platform; adjusting the level of the distributive girder; the pre-pressing point positions and the pre-embedded point positions on the same vertical line are connected through finish rolling deformed steel bars, the bottom ends of the finish rolling deformed steel bars are in threaded connection with lifting lug assemblies, the top ends of the finish rolling deformed steel bars sequentially penetrate through longitudinal beams, distribution beams and jacks arranged on the distribution beams, and the finish rolling deformed steel bars are in threaded connection with lower nuts and upper nuts. The lower nut is locked above the distribution beam, and the upper nut is locked above the jack; a plurality of jacks are simultaneously started and synchronously tensioned in a grading manner; and unloading. Classified synchronous tensioning of the multiple jacks is achieved, quick assembly and disassembly can be achieved, and the turnover rate is increased.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method and apparatus for synchronous preloading of the No. 0 block support. Background Technology

[0002] Currently, there are several methods for preloading the No. 0 block support, including the surcharge method, the neutral prestressing method, the symmetrical support method, and the mechanical preloading method with jacks. Among these, the surcharge method has problems such as difficulties in preloading transportation and loading / unloading, as well as high safety risks. The neutral prestressing method also has problems with loading / unloading difficulties. The symmetrical support method has problems such as complex frame structure and easy damage to the pier. The mechanical preloading method with jacks can save construction time and costs, and is safe and efficient, and is more widely used.

[0003] The conventional mechanical preloading method using jacks has the following disadvantages: the control precision of the jacks requires a high level of skill from the on-site installers, and it is difficult to achieve synchronous preloading, making it impossible to accurately simulate the weight distribution of the actual structure; reaction devices need to be pre-embedded in the pier cap to ensure that the steel strands are on the same vertical line; the length of the steel strands used for piers of different heights is inconsistent, making it difficult to reuse them, and the installation and dismantling are complicated and cannot be done quickly. Summary of the Invention

[0004] The purpose of this invention is to provide a synchronous preloading method and device for the No. 0 block support, so as to solve the problems of synchronous preloading difficulties and the complexity of installation and dismantling using steel strands in the mechanical preloading method with jacks.

[0005] To achieve this objective, the present invention adopts the following technical solution: A method for synchronous preloading of a No. 0 block support, wherein the No. 0 block support comprises, from bottom to top, steel pipe columns, crossbeams, longitudinal beams, and distribution beams arranged on a bearing platform; the method for synchronous preloading of the No. 0 block support includes the following steps: S1. Before the construction of the foundation, determine the embedded points on the foundation and the preloading points on the distribution beam, and determine the deformation monitoring points and stress monitoring points; the embedded points and the preloading points are on the same vertical line. S2, determine the pre-embedded depth of the lifting lug assembly based on the preload, and during the construction of the bearing platform, pre-embed part of the lifting lug assembly at the pre-embedded point on the bearing platform; S3, Adjust the level of the distribution beam; S4, the jacks at the pre-loading points on the same vertical line are connected to the lug assemblies at the pre-embedded points through precision-rolled threaded steel bars. The bottom end of the precision-rolled threaded steel bars is connected to the lug assemblies. The top end of the precision-rolled threaded steel bars is sequentially connected to the longitudinal beam, the distribution beam, and the jacks set on the distribution beam. The threaded steel bars are connected to the lower nut and the upper nut. The lower nut is locked above the distribution beam, and the upper nut is locked above the jacks. S5, multiple jacks are started simultaneously and tensioned synchronously in stages; S6, uninstall.

[0006] In some embodiments, the method for determining the preloading point in step S1 is as follows: The No. 0 main beam projected outside the pier is divided into several areas according to the flange, web, top plate and bottom plate. The preloading points are symmetrically set on both sides of the center of gravity of the flange and web along the bridge direction. The preloading points are also symmetrically set on both sides of the center of gravity of the top plate and bottom plate along the bridge direction. The stress monitoring points are spaced out along the transverse direction of the bridge on the longitudinal beam; The deformation monitoring points are spaced out along the transverse direction of the bridge on the longitudinal beams.

[0007] In some embodiments, in step S3, the end of the longitudinal beam away from the pier is inclined upward, and a first wedge-shaped pad is provided between the longitudinal beam and the distribution beam to adjust the level of the distribution beam.

[0008] In some embodiments, the graded synchronous tensioning in step S5 is performed in three stages according to 60%, 80%, and 100% of the preload, with multiple jacks starting tensioning simultaneously during each stage.

[0009] In some embodiments, the graded synchronous tensioning in step S5 specifically refers to: S51, reset the jack; S52, tighten the upper nut above the jack and tighten the lower nut above the distribution beam; S53, multiple jacks are started simultaneously and tension the precision rolled threaded steel bars in a synchronous manner, and the lower nut will gradually detach from the distribution beam under the action of the jacks; S54, after tensioning to the desired position, tighten the lower nut again and unload the jack. At this time, the tension load is transferred from the jack to the lower nut. S55, if the tension displacement of the jack exceeds the stroke of the jack, then repeat steps S51-S54 to proceed to the next stage of tensioning; otherwise, directly repeat steps S53-S54 to proceed to the next stage of tensioning, until all stages of tensioning are completed.

[0010] In some embodiments, the unloading in step S6 specifically involves: the jack being activated and lifting the upper nut, the lower nut being disengaged from the distribution beam, the lower nut being screwed upwards a certain distance, and then the jack being released until the unloading is complete.

[0011] A synchronous preloading device for a No. 0 block support is provided to implement the synchronous preloading method for the No. 0 block support provided by the present invention; the synchronous preloading device for the No. 0 block support includes: The lifting lug assembly includes an anchor bar, a pre-embedded lug plate, a lifting lug plate, and a connector. The top end of the anchor bar is fixedly connected to the pre-embedded lug plate. The bottom end of the anchor bar and part of the pre-embedded lug plate are pre-embedded at pre-embedded points on the bearing platform. The top end of the pre-embedded lug plate is rotatably installed with the lifting lug plate. The connector is located at the top end of the lifting lug plate. The jack is mounted on the distribution beam and located at the preload point; The fine-rolled threaded steel bar has its bottom end fixedly connected to the connector, and its top end is sequentially connected to a longitudinal beam, a distribution beam, and a jack. The fine-rolled threaded steel bar has a lower nut and an upper nut connected to its upper thread. The lower nut can be locked above the distribution beam, and the upper nut can be locked above the jack. A control system is communicatively connected to multiple jacks to control the multiple jacks to synchronously start tensioning.

[0012] In some embodiments, a horseshoe stirrup is provided between the distribution beam and the jack.

[0013] In some embodiments, a plurality of precision-rolled threaded steel bars are provided between the connector and the jack, connected by connecting nuts.

[0014] In some embodiments, the synchronous preloading device for the No. 0 block support further includes a hydraulic pressure sensor, which is mounted on the jack and communicates with the control system; hydraulic control valves are provided on the oil pipes of the plurality of jacks, and the hydraulic control valves are communicates with the control system.

[0015] In some embodiments, a pin is provided between the lifting lug plate and the embedded lug plate for rotatable connection.

[0016] The beneficial effects of this invention are: The synchronous preloading method for the No. 0 block support provided by this invention facilitates the staged synchronous tensioning of multiple jacks by setting a finely rolled threaded steel bar connected between the bearing platform and the distribution beam, and by using an upper nut and a lower nut threadedly connected to the finely rolled threaded steel bar, as well as jacks set on the distribution beam. Furthermore, the two ends of the finely rolled threaded steel bar are respectively threadedly connected to the lifting lug assembly and the upper nut, which enables rapid installation and disassembly, improves the preloading turnover efficiency of the No. 0 block support, and is conducive to recycling and reuse. Attached Figure Description

[0017] Figure 1 This is a flowchart of the synchronous pre-compression method for the No. 0 block support provided in an embodiment of the present invention; Figure 2 This is a flowchart of the graded synchronous tensioning process provided in an embodiment of the present invention; Figure 3 This is a top view of the support block 0 provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the first angle of the positional relationship between the support of block 0 and the main beam of block 0 provided in an embodiment of the present invention; Figure 5 This is a second-angle structural diagram illustrating the positional relationship between the support block 0 and the main beam block 0 provided in this embodiment of the invention. Figure 6 yes Figure 5 Enlarged structural diagram of region A in the middle; Figure 7 This is a schematic diagram showing the positional relationship between the jack and the precision-rolled threaded steel at the preload point; Figure 8 yes Figure 5 Enlarged structural diagram of region B in the middle; Figure 9 yes Figure 8 Schematic diagram of the CC section structure; Figure 10 This is the main view of the pre-embedded lifting lugs; Figure 11 This is the front view of the lug plate; Figure 12 yes Figure 11 Schematic diagram of the DD section structure; Figure 13 This is a top view of the lug plate.

[0018] In the picture: 100. Pier cap; 101. Pier; 200. Block 0 support; 201. Steel pipe column; 202. Crossbeam; 203. Longitudinal beam; 204. Distribution beam; 205. First wedge-shaped pad; 300. Block 0 main beam; 301. Web; 302. Flange; 303. Top plate; 304. Bottom plate; 1. Lifting lug assembly; 11. Anchor bar; 12. Embedded lug plate; 121. Fixing groove; 122. First mounting hole; 13. Lifting lug plate; 131. Second mounting hole; 132. Panel; 133. Sealing plate; 134. Gap; 14. Connector; 15. Pin; 2. Jack; 21. Oil pipe; 3. Precision rolled threaded steel bar; 4. Bottom nut; 5. Top nut; 6. Stirrup; 7. Connecting nut; 8. Hydraulic pressure sensor; 81. Cable; 9. Control system. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0023] This invention provides a method and apparatus for synchronous preloading of block 0 support, wherein, as shown in the embodiments of the present invention... Figures 3-5 As shown, the support 200 for block 0 includes, from bottom to top, steel pipe columns 201, crossbeams 202, longitudinal beams 203, and distribution beams 204 arranged on the pier 100. A pier 101 is installed on the pier 100. The support 200 is located on the pier 100 along the longitudinal direction of the bridge (…). Figure 3Multiple steel pipe columns 201 are spaced apart on both sides of the bridge (in the X direction). Each crossbeam 202 is set on the unloading block on the multiple steel pipe columns 201 along the transverse direction (perpendicular to the longitudinal direction). The longitudinal beam 203 is set on the crossbeam 202 along the longitudinal direction. The longitudinal beam 203 is inclined from low to high in the direction from one end facing the pier 101 to the other end away from the pier 101. A second wedge-shaped pad is set between the crossbeam 202 and the longitudinal beam 203 to support the longitudinal beam 203. The distribution beam 204 is set on the longitudinal beam 203 along the transverse direction. Since the longitudinal beam 203 is an inclined beam, a first wedge-shaped pad 205 is set between the longitudinal beam 203 and the distribution beam 204 to support the distribution beam 204 and to adjust and ensure the level of the distribution beam 204.

[0024] like Figure 1 As shown, the synchronous preloading method for the No. 0 block support provided in this embodiment of the invention includes the following steps: S1. Before the construction of the pier cap 100, determine the embedded points on the pier cap 100 and the preloading points on the distribution beam 204, and determine the deformation monitoring points and stress monitoring points; the embedded points and the preloading points are on the same vertical line. S2, based on the preload, determine the pre-embedded depth of the lifting lug assembly 1, and during the construction of the foundation 100, pre-embed part of the lifting lug assembly 1 at the pre-embedded point on the foundation 100; S3, adjust the level of distribution beam 204 to ensure the stability of the preloading process.

[0025] S4, the jack 2 at the pre-loading point on the same vertical line is connected to the lug assembly 1 at the pre-embedded point through the fine-rolled threaded steel bar 3. The bottom end of the fine-rolled threaded steel bar 3 is connected to the lug assembly 1. The top end of the fine-rolled threaded steel bar 3 is sequentially connected to the longitudinal beam 203, the distribution beam 204 and the jack 2 set on the distribution beam 204. The threaded steel bar 3 is connected to the lower nut 4 and the upper nut 5. The lower nut 4 is locked above the distribution beam 204 and the upper nut 5 is locked above the jack 2. S5, multiple jacks 2 are started simultaneously and tensioned in stages; S6, uninstall.

[0026] The synchronous preloading method for the No. 0 block support provided by this invention utilizes a precision-rolled threaded steel bar 3 connected between the bearing platform 100 and the distribution beam 204. An upper nut 5 and a lower nut 4 are threaded onto the precision-rolled threaded steel bar 3, and jacks 2 are mounted on the distribution beam 204. This facilitates the staged synchronous tensioning of multiple jacks 2. Furthermore, the two ends of the precision-rolled threaded steel bar 3 are threadedly connected to the lifting lug assembly 1 and the upper nut 5, respectively, enabling rapid installation and disassembly. This improves the preloading turnover efficiency of the No. 0 block support 200 and facilitates recycling. It should be noted that, to achieve synchronous activation and application of tension force by multiple jacks 2, hydraulic jacks can be used, and the tension force can be controlled by controlling the hydraulic pressure.

[0027] In step S1, after the preloading points are determined, the pre-embedded points can be determined based on the characteristics of a uniform vertical line. The method for determining the preloading points is as follows: The main beam 300 of block 0, projected outside pier 101, is divided into several areas according to the flange 302, web 301, top plate 303 and bottom plate 304. Preloading points are symmetrically set on both sides of the center of gravity of the flange 302 and web 301 along the bridge direction. Preloading points are also symmetrically set on both sides of the center of gravity of the top plate 303 and bottom plate 304 along the bridge direction. Stress monitoring points are spaced out along the transverse direction of the bridge on multiple longitudinal beams 203; Deformation monitoring points are set at intervals along the transverse direction of the bridge on the longitudinal beam 203.

[0028] like Figures 3-5 As shown, the support 200 for block 0 is used for the portion of the main beam 300 of block 0 extending outward from the pier 101. The main beam 300 of block 0 is formed by concrete casting. In this embodiment, the structure of the main beam 300 of block 0 includes a flange 302, a web 301, a top plate 303, and a bottom plate 304. The flange 302, web 301, top plate 303, and bottom plate 304 are divided into multiple regions. The center of gravity of each region is the location of the preloading point of the jack 2. In order to more accurately simulate the actual load distribution when the jack 2 is tensioned in stages, multiple preloading points are set at intervals on the distribution beam 204 to form multiple rows of preloading points. Figure 3 Taking the side with the small pile number as an example, the bridge pier 101 is symmetrically set on both sides. P1-P16 are preloading points, S1-S6 are stress monitoring points, and B1-B8 are deformation monitoring points. Among them, the preloading load of point P1+point P2 represents the weight of the left wing plate 302+left web plate 301, the preloading load of point P3+point P4+point P5+point P6 represents the weight of the top plate 303+bottom plate 304, and the preloading load of point P7+point P8 represents the weight of the right wing plate 302+right web plate 301. Both stress and deformation monitoring points are located at the midpoint of the two rows of preloading points along the bridge direction. Three stress monitoring points are symmetrically arranged on each cantilever side: points S1, S2, and S3, and points S4, S5, and S6. When the longitudinal beam 203 uses a T-beam, the stress monitoring points are located on the lower flange of the corresponding longitudinal beam 203, and deformation monitoring points B1-B8 are located on the upper flange of the corresponding longitudinal beam 203. This allows for real-time monitoring of the stress and deformation of the longitudinal beam 203 during tensioning. Several preloading points can more accurately simulate the actual load distribution, thus ensuring tensioning accuracy. Typically, stress and deformation monitoring points are set at locations on the longitudinal beam 203 with higher stress and deformation based on calculated data.

[0029] In step S3, the end of the longitudinal beam 203 furthest from the pier 101 is inclined upwards, and a first wedge-shaped pad 205 is placed between the longitudinal beam 203 and the distribution beam 204 to adjust the level of the distribution beam 204. Combined with... Figure 5 and Figure 6 As shown, the first wedge-shaped pad 205 above the longitudinal beam 203 allows the distribution beam 204 to be adjusted to a horizontal position, which helps ensure balanced force during tensioning. The first wedge-shaped pad 205 can have different wedge angles at different positions on the longitudinal beam 203, and it can be welded and fixed to the longitudinal beam 203. The first wedge-shaped pad 205 and the second wedge-shaped pad can be set up with similar structures.

[0030] In step S5, the graded synchronous tensioning is performed in three stages: 60%, 80%, and 100% of the preload. During each stage, multiple jacks 2 are simultaneously activated. The preload is applied in three stages according to a preset control value, which solves the problem of insufficient stroke of the jacks 2 and the problem of multiple jacks 2 not being able to tension synchronously in the prior art. Subsequent tensioning and preceding tensioning accumulate under the action of the lower nut 4, achieving synchronous application and precise control of the preload. In some embodiments, when the preload is large, the number of stages of graded synchronous tensioning can be increased to further improve the tensioning accuracy.

[0031] In some embodiments, such as Figure 2 As shown, the staged synchronous tensioning in step S5 specifically involves: S51, reset jack 2; S52, tighten the upper nut 5 above the jack 2, and tighten the lower nut 4 above the distribution beam 204; S53, multiple jacks 2 start simultaneously and tension the precision rolled threaded steel bar 3 in a synchronous manner, and the lower nut 4 will gradually detach from the distribution beam 204 under the action of the jacks 2; S54, after tensioning to the desired position, tighten the lower nut 4 again and unload the jack 2. At this time, the tensioning load is transferred from the jack 2 to the lower nut 4. S55, if the tension displacement of jack 2 exceeds the stroke of jack 2, repeat steps S51-S54 to proceed to the next stage of tensioning; otherwise, directly repeat steps S53-S54 to proceed to the next stage of tensioning, until all stages of tensioning are completed.

[0032] In the above steps, following the three-stage synchronous tensioning procedure, after three tensioning operations, tightening the lower nut 4 each time transfers the tension force or load of the jack 2 to the lower nut 4, which improves the tensioning distance and accuracy and solves the problem that the jack 2 cannot maintain pressure and load for a long time. The staged synchronous tensioning uses precision-rolled threaded steel bars 3 in conjunction with the upper nut 5 and the lower nut 4, solving the problems of complex fixing and operation in existing technologies using steel strand tensioning. The precision-rolled threaded steel bars 3 can be extended using connecting nuts 7, eliminating the need for matching anchor clamps, resulting in a simple structure that is easy to assemble and disassemble.

[0033] In some embodiments, unloading in step S6 specifically involves: jack 2 starting and lifting the upper nut 5, the lower nut 4 disengaging from the distribution beam 204, the lower nut 4 being screwed upwards a certain distance, and then jack 2 being loosened until completely unloaded, completing one preload cycle. It should be noted that when jack 2 starts tensioning, multiple jacks 2 start synchronously and apply tension force according to their respective preload loads. To achieve synchronous tensioning of multiple jacks 2, such as... Figure 6 and Figure 7 As shown, the jack 2 is a hydraulic jack 2. An oil pressure sensor 8 is installed on the jack 2 to detect the pressure of the jack 2 in real time. The cable 81 of the oil pressure sensor 8 and the oil pipe 21 of the jack 2 are both connected to the control system 9 for pressure control. Specifically, the control system 9 controls the liquid pressure through the oil pipe 21 and performs detection based on the detection data of the oil pressure sensor 8 to ensure the accuracy of the tension force.

[0034] To achieve the synchronous pre-compression method for the No. 0 block support provided by the present invention, this embodiment also provides a synchronous pre-compression device for the No. 0 block support, such as... Figures 5-13 The synchronous preloading device for the No. 0 block support includes a lifting lug assembly 1, a jack 2, a precision-rolled threaded steel bar 3, and a control system 9. The lifting lug assembly 1 includes an anchor bar 11, a pre-embedded ear plate 12, a lifting ear plate 13, and a connector 14. The top of the anchor bar 11 is fixedly connected to the pre-embedded ear plate 12. The bottom of the anchor bar 11 and part of the pre-embedded ear plate 12 are pre-embedded at pre-embedded points on the bearing platform 100. The top of the pre-embedded ear plate 12 is rotatably installed with the lifting ear plate 13. The connector 14 is located at the top of the lifting ear plate 13. The jack 2 is located at... The distribution beam 204 is located at the pre-stressing point; the bottom end of the fine-rolled threaded steel bar 3 is fixedly connected to the connector 14, and the top end of the fine-rolled threaded steel bar 3 is sequentially threaded through the longitudinal beam 203, the distribution beam 204 and the jack 2. The fine-rolled threaded steel bar 3 is threadedly connected to the lower nut 4 and the upper nut 5. The lower nut 4 can be locked above the distribution beam 204, and the upper nut 5 can be locked above the jack 2; the control system 9 communicates with multiple jacks 2 to control multiple jacks 2 to start tensioning synchronously.

[0035] like Figure 6 and Figure 7A horseshoe-shaped stirrup 6 is provided between the distribution beam 204 and the jack 2. A nut 4 is threadedly connected to a precision-rolled threaded steel bar 3 and located within the horseshoe-shaped stirrup 6. The horseshoe-shaped stirrup 6 facilitates the installation and fixing of the jack 2. The connector 14 uses a long-shaft nut to increase the connection strength with the precision-rolled threaded steel bar 3. Figure 9 and Figure 10 As shown, the embedded ear plate 12 is made of steel plate, such as Q345, with a thickness of 25mm. A 20mm wide fixing groove 121 is cut into the embedded ear plate 12, and then beveled. Four anchor bars 11, each with a diameter of 28mm, are fixed in the fixing groove 121 using double-sided welding. The anchor bars 11 and part of the embedded ear plate 12 are pre-embedded in the foundation 100 during construction. The top of the embedded ear plate 12 protrudes at least 25cm above the surface of the foundation 100. Furthermore, the bottom of the anchor bars 11 is bent to improve stability. The top of the pre-embedded ear plate 12 has a semi-circular arc structure. The area of ​​the pre-embedded ear plate 12 exposed above the bearing platform 100 has a first mounting hole 122. The lifting ear plate 13 has a second mounting hole 131. The pin 15 passes through both the first mounting hole 122 and the second mounting hole 131 to realize the rotational installation between the lifting ear plate 13 and the pre-embedded ear plate 12. The connection through the pin 15 ensures that the connection can adapt to a certain rotation, ensuring that the axial force is borne when the fine rolled threaded steel bar 3 is tensioned. At the same time, it can ensure the quick installation, disassembly and recycling of the lifting ear plate 13 and the connector 14.

[0036] The structure of the lifting plate 13 is as follows Figures 11-13 As shown, the lifting lug plate 13 includes two spaced-apart panels 132 and two sealing plates 133 connected to both sides of the two panels 132. Both panels 132 and sealing plates 133 are made of steel plate. The two sides of the sealing plates 133 are welded and fixed to the edges of the two panels 132, forming a gap 134 between the two panels 132. A first mounting hole 122 is provided on the two panels 132, allowing the top end of the pre-embedded lug plate 12 to pass through the gap 134 and be rotatably installed. The sealing plates 133 limit the range of rotation angle between the pre-embedded lug plate 12 and the lifting lug plate 13. The top ends of the two panels 132 of the lifting lug plate 13 have opening slots, and a connector 14 is welded and fixed within these slots. The bottom end of the precision-rolled threaded steel bar 3 is threadedly connected and fixed to the connector 14.

[0037] In some embodiments, a plurality of finely rolled threaded steel bars 3 are provided between the connector 14 and the jack 2, connected by connecting nuts 7. For example... Figure 5 As shown, when the height of the 0th block bracket 200 is too large, resulting in insufficient length of a single fine-rolled threaded steel bar 3, two fine-rolled threaded steel bars 3 can be connected by connecting nuts 7 to extend the fine-rolled threaded steel bars 3. This achieves good coaxiality and facilitates quick assembly and disassembly.

[0038] In some embodiments, the synchronous preloading device for the No. 0 block support further includes a hydraulic pressure sensor 8, which is mounted on the jack 2 and communicates with the control system 9; hydraulic control valves are provided on the oil pipes 21 of the multiple jacks 2, and the hydraulic control valves communicate with the control system 9.

[0039] like Figure 6 and Figure 7 Hydraulic pressure sensors 8 are installed on jacks 2 to detect the pressure in the oil chamber of jacks 2. The cables 81 of the hydraulic pressure sensors 8 on each jack 2 are connected to the control system 9 for communication, facilitating real-time acquisition of pressure information from jacks 2. This enables real-time detection and control of the pressure in jacks 2. Furthermore, the placement of the hydraulic pressure sensors 8 on jacks 2 improves detection accuracy and avoids the large tension error caused by pressure loss within the oil pipe 21 when only the input pressure is controlled by the control system 9, thus improving tensioning accuracy. To achieve pressure control between the control system 9 and jacks 2, one approach is to connect the control system 9 to the oil pipe 21 of each jack 2. By installing solenoid valves on the oil pipes 21, the control system 9 controls the solenoid valves to control the oil pressure or flow rate, achieving synchronous tensioning control of multiple jacks 2.

[0040] The synchronous preloading device for the No. 0 block support provided by this invention adopts mechanical preloading with jacks 2 and achieves assembly and disassembly through the threaded fit structure of the precision-rolled threaded steel bar 3, which improves the efficiency of disassembly and assembly and the turnover rate. The precision-rolled threaded steel bar 3 can be freely connected according to the height of the pier 101. After tensioning, only the lower nut 4 needs to be tightened to achieve the bearing of the tension force, without the need for matching anchor clamps, which simplifies the synchronous preloading process and structure. Since the setting of the preloading point is combined with the center of gravity of the No. 0 block main beam 300, the accurate simulation of the actual load distribution is achieved. The traditional mechanical preloading method with jacks 2 cannot achieve synchronous tensioning. During the staged tensioning process, subsequent tensioning will cause unloading of the previous tensioning, affecting the tensioning effect. This invention uses the control system 9 to collect the pressure on the jacks 2 and control it uniformly through the control oil pipe 21. All the oil pipes 21 of the jacks 2 are connected to the control system 9, which can avoid the influence of oil pressure loss on the oil pipe 21 on the tensioning accuracy and ensure the synchronous application and accurate control of the preloading load.

[0041] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for synchronous preloading of a No. 0 block support, wherein the No. 0 block support (200) comprises, from bottom to top, steel pipe columns (201), crossbeams (202), longitudinal beams (203), and distribution beams (204) arranged on a foundation (100); characterized in that, The synchronous preloading method for the No. 0 block support includes the following steps: S1, Before the construction of the foundation (100), determine the pre-embedded points on the foundation (100) and the pre-stressing points on the distribution beam (204), and determine the deformation monitoring points and stress monitoring points; the pre-embedded points and the pre-stressing points are on the same vertical line; S2, based on the preload, determine the pre-embedded depth of the lug assembly (1), and during the construction of the pier (100), pre-embed part of the lug assembly (1) at the pre-embedded point on the pier (100); S3, adjust the level of the distribution beam (204); S4, the jack (2) at the pre-pressing point on the same vertical line is connected to the lug assembly (1) at the pre-embedded point through a fine-rolled threaded steel bar (3). The bottom end of the fine-rolled threaded steel bar (3) is threaded to the lug assembly (1). The top end of the fine-rolled threaded steel bar (3) is sequentially connected to the longitudinal beam (203), the distribution beam (204), and the jack (2) set on the distribution beam (204). The fine-rolled threaded steel bar (3) is threaded to the lower nut (4) and the upper nut (5). The lower nut (4) is locked above the distribution beam (204), and the upper nut (5) is locked above the jack (2). S5, multiple jacks (2) are started simultaneously and tensioned synchronously in stages; S6, uninstall.

2. The synchronous preloading method for the No. 0 block support according to claim 1, characterized in that, In step S1, the method for determining the preloading point is as follows: The main beam (300) of block 0, which is projected outside the pier (101), is divided into several regions according to the flange (302), web (301), top plate (303) and bottom plate (304). The preloading points are symmetrically arranged on both sides of the center of gravity of the flange (302) and web (301) along the bridge direction. The preloading points are also symmetrically arranged on both sides of the center of gravity of the top plate (303) and bottom plate (304) along the bridge direction. The stress monitoring points are spaced out along the transverse direction on the longitudinal beam (203); The deformation monitoring points are spaced apart along the transverse direction of the bridge on the longitudinal beam (203).

3. The synchronous preloading method for the No. 0 block support according to claim 1, characterized in that, In step S3, the end of the longitudinal beam (203) away from the pier (101) is inclined upward, and a first wedge-shaped pad (205) is set between the longitudinal beam (203) and the distribution beam (204) to adjust the level of the distribution beam (204).

4. The synchronous preloading method for the No. 0 block support according to claim 1, characterized in that, In step S5, the graded synchronous tensioning is carried out in three stages according to 60%, 80% and 100% of the preload. During each stage of tensioning, multiple jacks (2) are started synchronously.

5. The synchronous pre-compression method for the No. 0 block support according to claim 4, characterized in that, The graded synchronous tensioning mentioned in step S5 specifically refers to: S51, reset the jack (2); S52, tighten the upper nut (5) above the jack (2) and tighten the lower nut (4) above the distribution beam (204); S53, multiple jacks (2) are started simultaneously and tension the fine-rolled threaded steel (3) synchronously, and the lower nut (4) will gradually detach from the distribution beam (204) under the action of the jacks (2); S54, after tensioning to the position, tighten the lower nut (4) again and unload the jack (2). At this time, the tensioning load is transferred from the jack (2) to the lower nut (4). S55, if the tension displacement of the jack (2) exceeds the stroke of the jack (2), then repeat steps S51-S54 to enter the next stage of tensioning; otherwise, directly repeat steps S53-S54 to enter the next stage of tensioning until all stages of tensioning are completed.

6. The synchronous preloading method for the No. 0 block support according to claim 1, characterized in that, The unloading in step S6 is specifically as follows: the jack (2) is activated and lifts the upper nut (5), the lower nut (4) is disengaged from the distribution beam (204), the lower nut (4) is turned upwards a certain distance, and then the jack (2) is released until the unloading is complete.

7. A synchronous preloading device for a No. 0 block support, used to implement the synchronous preloading method for the No. 0 block support as described in any one of claims 1-6; characterized in that, The synchronous preloading device for the No. 0 block support includes: The lifting lug assembly (1) includes an anchor bar (11), a pre-embedded lug plate (12), a lifting lug plate (13), and a connector (14). The top end of the anchor bar (11) is fixedly connected to the pre-embedded lug plate (12). The bottom end of the anchor bar (11) and part of the pre-embedded lug plate (12) are pre-embedded at pre-embedded points on the support platform (100). The top end of the pre-embedded lug plate (12) is rotatably installed with the lifting lug plate (13). The connector (14) is located at the top end of the lifting lug plate (13). Jack (2), the jack (2) is set on the distribution beam (204) and located at the preload point; A precision-rolled threaded steel bar (3) is provided, with its bottom end fixedly connected to the connector (14). The top end of the precision-rolled threaded steel bar (3) is sequentially connected to the longitudinal beam (203), the distribution beam (204), and the jack (2). The precision-rolled threaded steel bar (3) is threadedly connected to a lower nut (4) and an upper nut (5). The lower nut (4) can be locked above the distribution beam (204), and the upper nut (5) can be locked above the jack (2). The control system (9) is communicatively connected to multiple jacks (2) to control the multiple jacks (2) to start tensioning synchronously.

8. The synchronous preloading device for the No. 0 block support according to claim 7, characterized in that, A horseshoe stirrup (6) is provided between the distribution beam (204) and the jack (2).

9. The synchronous preloading device for the No. 0 block support according to claim 7, characterized in that, Multiple precision-rolled threaded steel bars (3) are provided between the connector (14) and the jack (2) and are connected by connecting nuts (7).

10. The synchronous preloading device for the No. 0 block support according to claim 7, characterized in that, It also includes an oil pressure sensor (8), which is installed on the jack (2) and is communicatively connected to the control system (9); a hydraulic control valve is provided on the oil pipe (21) of the multiple jacks (2), and the hydraulic control valve is communicatively connected to the control system (9).

11. The synchronous preloading device for the No. 0 block support according to claim 7, characterized in that, A pin (15) is inserted between the lifting lug plate (13) and the pre-embedded lug plate (12) for rotatable connection.

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