A high-precision installation construction method for precast capping beams

Abstract

The present invention provides a high-precision installation construction method for precast coping beams, which relates to the technical field of building construction. The method includes: erecting a coping beam support system, calibrating the elevation control points of the grout retaining plate on the pier column according to the bottom elevation of the coping beam, and calibrating a plurality of coping beam reference control points on the coping beam support system according to the size of the coping beam; sequentially placing the grout retaining plate and adjusting pads according to the elevation control points of the grout retaining plate, conducting the initial lifting of the coping beam, adjusting and verifying the elevation of the coping beam, and performing mortar bedding after the initial lifting is completed; moving the coping beam to a position at a preset distance above the adjusting pads, respectively verifying and adjusting the falling position of the coping beam according to a plurality of coping beam reference control points, and vertically lowering the coping beam after verification; after the lowering is completed, conducting a review of the coping beam, and removing the lifting ropes after the review is correct to complete the installation of the coping beam. Through the elevation control points of the grout retaining plate and the coping beam reference control points, the elevation and horizontal position of each reference point during the installation of the coping beam are verified, and the precise installation of the coping beam is completed, which can accurately ensure the installation accuracy of the coping beam.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular, to a high-precision installation construction method for precast capping beams. Background Art

[0002] Prefabricated bridges have the advantages of improving quality, shortening the construction period, reducing costs, reducing the impact on existing traffic and the environment, and meeting the needs of urban bridge construction. In recent years, starting from initially only targeting the upper structure of bridges, it has gradually covered the lower pier structures of bridges, forming a fully prefabricated bridge system, which has developed rapidly and is in the ascendant. As a key component of the bridge lower structure, precast capping beams are mostly connected to the lower columns through grouted metal corrugated pipes, and can be divided into integral precast capping beams and segmental precast capping beams according to the bridge deck span. After the segmental precast capping beams are connected to the columns, wet joints between segments need to be cast and prestressed to form a whole.

[0003] As a prefabricated and assembled process, the requirements for the manufacturing and installation accuracy of components are relatively high. According to the requirements of the "Technical Specification for Prefabricated Urban Bridge Engineering", for precast capping beams, the allowable deviation of their geometric dimensions reaches ±5 mm, the deviation of the center line position of the embedded grouting corrugated pipe and the reserved inserted steel bars is 2 - 3 mm, the allowable deviation of the offset and the height difference of the top joint between adjacent segments after installation is 3 mm, and the allowable deviation of the axis deviation of the upper bearing is 3 mm. How to ensure its manufacturing and installation accuracy is a key problem that must be solved. For ensuring the installation accuracy, some people have proposed a precast capping beam installation construction method based on three-dimensional measurement and lofting technology. It is necessary to first use a three-dimensional laser scanner to scan the appearance of the column capping beam and perform 3D modeling, then perform virtual pre-assembly in the cloud system, and then set up special climbing devices and lofting robots on site, and control the overall installation accuracy of the capping beam according to the pre-assembly coordinates of the cloud system; some people also achieve the installation positioning of the capping beam by adding a guiding groove for the capping beam body and a positioning device for the column hoop. The former needs to additionally install equipment such as a three-dimensional laser scanner, a cloud system, special climbing devices, and lofting robots. On the one hand, the cost is high, and on the other hand, the corresponding equipment has high requirements for the operation level of personnel, and its universality is relatively weak at the current stage; the latter affects the structural aesthetics and is time-consuming and laborious because it needs to add a guiding groove to the capping beam, and it is not convenient enough.

[0004] Therefore, aiming at the deficiencies of the existing technology, in order to improve the construction efficiency, save costs, ensure the installation accuracy, and improve the construction quality, the present invention proposes a construction method applied to the installation of precast capping beams. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision installation construction method for precast capping beams, which can propose solutions for the deficiencies in the existing technology, and has the characteristics of accurately ensuring the installation accuracy of the capping beam, improving the construction efficiency and construction quality, and saving construction costs.

[0006] An embodiment of the present invention provides a high-precision installation construction method for a prefabricated cap beam, comprising the following steps:

[0007] Erecting a cap beam support system, calibrating a slurry retaining plate elevation control point on the pier column according to the cap beam bottom elevation, and calibrating a plurality of cap beam reference control points on the cap beam support system according to the cap beam size;

[0008] Place the slurry retaining plate and the adjusting pad in sequence according to the elevation control point of the slurry retaining plate, carry out the initial trial hoisting of the cap beam, adjust and verify the elevation of the cap beam, and place the slurry after the initial trial hoisting is completed;

[0009] The cap beam is moved to a position at a preset distance above the adjustment pad, and the falling position of the cap beam is verified and adjusted according to a plurality of cap beam reference control points. After verification, the cap beam is lowered vertically;

[0010] After lowering is completed, the cap beam is checked according to the cap beam reference control points. After the check is correct, the slings are removed to complete the cap beam installation.

[0011] In some embodiments of the present invention, the steps of erecting a cap beam support system, calibrating a slurry retaining plate elevation control point on a pier column according to the cap beam bottom elevation, and calibrating a plurality of cap beam reference control points on the cap beam support system according to the cap beam size include:

[0012] Setting up a temporary support and operating platform, and setting an adjustment sand box on the operating platform according to the requirements for adjusting the height of the cap beam;

[0013] Marking the elevation control points of the slurry retaining plate on the pier column according to the bottom elevation of the cap beam; wherein the elevation control points of the slurry retaining plate are marked on the four sides of the pier column respectively;

[0014] According to the size of the cap beam, the transverse center line of the bottom of the cap beam, the upper edge control point of the center line and the longitudinal edge control point of the cap beam are calibrated on the I-beam crossbeam of the cap beam support system.

[0015] In some embodiments of the present invention, the steps of sequentially placing the slurry guard plates and adjusting pads according to the slurry guard plate elevation control points, performing an initial trial hoisting of the cap beam, adjusting and verifying the elevation of the cap beam, and performing slurry seating after the initial trial hoisting is completed include:

[0016] Placing a slurry guard plate at the edge of the pier column according to the slurry guard plate elevation control point, and placing a plurality of adjustment pads on the top of the pier column; wherein the elevation of the top surface of the slurry guard plate is higher than the elevation of the top surface of the adjustment pad by a certain distance;

[0017] Slowly placing the cap beam on the pier and the adjusting sand box, adjusting the elevation of the adjusting sand box, and verifying the elevation of the cap beam, completing the initial trial hoisting of the cap beam;

[0018] Install a grout stop pad on the reserved steel bars of the pier column, perform mortar bedding, grout into the retaining plate, and level it. Among them, the elevation of the mortar surface is consistent with the elevation of the built-in adjusting pad and slightly higher than the adjusting pad.

[0019] In some embodiments of the present invention, the step of moving the capping beam to a position at a preset distance above the adjusting pad, respectively verifying and adjusting the falling position of the capping beam based on a plurality of capping beam reference control points, and vertically lowering the capping beam after verification includes:

[0020] Move the capping beam to a position at a preset distance above the adjusting pad; wherein, the preset distance is 1 cm - 2 cm;

[0021] Respectively verify and adjust the front, rear, left, and right positions of the capping beam based on the transverse center line at the bottom of the capping beam, the control point at the upper edge of the center line, and the longitudinal edge control points of the capping beam;

[0022] Vertically lower the capping beam after verification.

[0023] In some embodiments of the present invention, the step of placing the capping beam on the pier column and the adjusting sand box, adjusting the elevation of the adjusting sand box, and verifying the elevation of the capping beam to complete the initial hoisting of the capping beam includes:

[0024] After adjusting the adjusting sand box, verify the elevation of the capping beam in the transverse bridge direction and the elevation of the capping beam in the longitudinal bridge direction.

[0025] In some embodiments of the present invention, the step of respectively verifying the front, rear, left, and right positions of the capping beam based on the transverse center line at the bottom of the capping beam, the control point at the upper edge of the center line, and the longitudinal edge control points of the capping beam includes:

[0026] Verify the longitudinal bridge center position and the transverse bridge edge position of the inner side of the capping beam based on the inner control point at the upper edge of the center line, and verify the longitudinal bridge center position and the transverse bridge edge position of the outer side of the capping beam based on the outer control point at the upper edge of the center line;

[0027] Verify the longitudinal bridge edge position of the inner side of the capping beam based on the inner longitudinal edge control point of the capping beam, and verify the longitudinal bridge edge position of the outer side of the capping beam based on the outer longitudinal edge control point of the capping beam.

[0028] In some embodiments of the present invention, it further includes:

[0029] Cure the mortar cushion layer of the installed capping beam for 24 hours, and then perform corrugated pipe grouting.

[0030] In some embodiments of the present invention, it further includes:

[0031] Bind steel bars and pour concrete for the wet joints between multiple segments of the capping beams. After pouring, remove the formwork and cure.

[0032] After curing, perform prestress tensioning to connect multiple segments of the capping beams into one body.

[0033] In some embodiments of the present invention, the adjusting sand box is a cylindrical steel cylinder filled with fine sand. There are concrete or steel piers on the fine sand, and an opening and closing port for releasing the fine sand is provided at the bottom of the side of the adjusting sand box.

[0034] In some embodiments of the present invention, the temporary support includes multiple groups of support frames and a plurality of I-beam crossbeams arranged on the tops of the support frames. The support frames include a plurality of columns and cross braces and diagonal braces arranged between adjacent columns; the operation platform is a plurality of spliced wooden boards laid on the I-beam crossbeams.

[0035] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0036] The present invention includes the following steps: erect a capping beam support system, mark the elevation control points of the splash guard on the pier columns according to the bottom elevation of the capping beam, and mark a plurality of capping beam reference control points on the capping beam support system according to the size of the capping beam; place the splash guard and adjusting pads in sequence according to the elevation control points of the splash guard, perform the initial lifting of the capping beam, adjust and verify the elevation of the capping beam, and perform mortar bedding after the initial lifting is completed; move the capping beam to a position at a preset distance above the adjusting pads, respectively verify and adjust the falling position of the capping beam according to a plurality of the capping beam reference control points, and vertically lower the capping beam after verification; after lowering, perform a review of the capping beam according to the capping beam reference control points, and remove the lifting ropes after verification to complete the installation of the capping beam. Through the elevation control points of the splash guard and the capping beam reference control points marked by the bottom elevation and size of the capping beam, verify the elevation of each reference point during the installation of the capping beam and ensure the accurate horizontal position of the capping beam, complete the precise installation of the capping beam, which is easy to understand, simple and convenient, easy to master, without adding other additional aids, without increasing additional costs, and can accurately ensure the installation accuracy of the capping beam, providing a useful reference for the installation control of precast bridge capping beams and having great popularization and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 The figure shows a schematic diagram of the precast capping beam installation structure in an embodiment of the present invention;

[0039] Figure 2 The figure shows a top view of the support system in an embodiment of the present invention;

[0040] Figure 3 The figure shows a schematic diagram of the pier column structure in an embodiment of the present invention;

[0041] Figure 4 The figure shows a schematic diagram of the layout for calibrating the reference control points of the capping beam in an embodiment of the present invention;

[0042] Figure 5 The figure shows a schematic diagram of the distribution of corrugated pipes and grouting pipes in an embodiment of the present invention;

[0043] Figure 6 The figure shows a schematic diagram of the connection structure between the capping beam and the pier column in an embodiment of the present invention.

[0044] Reference numerals: 1, capping beam; 2, support system; 200, operating platform; 210, temporary support; 211, column; 212, cross brace; 213, diagonal brace; 214, backing plate; 3, pier column; 4, adjusting cushion block; 5, adjusting sand box; 6, elevation control point of the slurry retaining plate; 7, transverse center line at the bottom of the capping beam; 8, control point at the upper edge of the center line; 9, longitudinal edge control point of the capping beam; 10, grouting pipe; 11, corrugated pipe; 12, wet joint; 13, slurry retaining plate. Detailed implementation manners

[0045] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0048] In the description of the embodiments of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0049] In addition, if terms such as "horizontal", "vertical", "hanging" are used, it does not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0050] In the description of the embodiments of the present invention, "a plurality of" represents at least two.

[0051] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0052] Embodiment

[0053] As Figures 1 - 6 shown, Figure 1 shown is a schematic diagram of the installation structure of a precast capping beam in an embodiment of the present invention; Figure 2 shown is a top view of the support system in an embodiment of the present invention; Figure 3 shown is a schematic diagram of the pier column structure in an embodiment of the present invention; Figure 4 shown is a schematic diagram of the layout for calibrating the reference control points of the capping beam in an embodiment of the present invention; Figure 5 shown is a schematic diagram of the distribution of corrugated pipes and grouting pipes in an embodiment of the present invention;

[0054] Figure 6 shown is a schematic diagram of the connection structure between the capping beam and the pier column in an embodiment of the present invention;

[0055] The embodiments of the present application provide a high-precision installation construction method for a precast capping beam, including the following steps:

[0056] S1. Erect the bent cap support system 2. Mark the elevation control points 6 of the splash guard on the pier column 3 according to the bottom elevation of the bent cap 1, and mark multiple bent cap reference control points on the bent cap support system 2 according to the size of the bent cap 1.

[0057] S2. Place the splash guard 13 and the adjusting cushion blocks 4 in sequence according to the elevation control points 6 of the splash guard, conduct the initial lifting of the bent cap 1, adjust and verify the elevation of the bent cap 1 and conduct the initial lifting of the bent cap 1. After the initial lifting is completed, grout is placed.

[0058] S3. Move the bent cap 1 to a position at a preset distance above the adjusting cushion block 4, verify and adjust the lowering position of the bent cap 1 respectively according to multiple bent cap reference control points. After verification, lower the bent cap 1 vertically.

[0059] S4. After the lowering is completed, conduct a review of the bent cap 1 according to the bent cap reference control points. After verification, remove the lifting ropes to complete the installation of the bent cap 1.

[0060] The present invention includes the following steps: Erect the bent cap support system 2. Mark the elevation control points 6 of the splash guard on the pier column 3 according to the bottom elevation of the bent cap 1, and mark multiple bent cap reference control points on the bent cap support system 2 according to the size of the bent cap 1. Place the splash guard 13 and the adjusting cushion blocks 4 in sequence according to the elevation control points 6 of the splash guard, conduct the initial lifting of the bent cap 1, adjust and verify the elevation of the bent cap 1. After the initial lifting is completed, grout is placed. Move the bent cap 1 to a position at a preset distance above the adjusting cushion block 4, verify and adjust the lowering position of the bent cap 1 respectively according to multiple bent cap reference control points. After verification, lower the bent cap 1 vertically. After the lowering is completed, conduct a review of the bent cap 1 according to the bent cap reference control points. After verification, remove the lifting ropes to complete the installation of the bent cap 1. Through the elevation control points 6 of the splash guard and the bent cap reference control points marked by the bottom elevation of the bent cap 1 and the size of the bent cap 1, verify the elevation of each reference point during the installation of the bent cap 1 and ensure the accurate horizontal position of the bent cap 1, complete the precise installation of the bent cap 1, which is easy to understand, simple and convenient, easy to master, without adding other additional aids, without increasing the remaining costs, and can accurately ensure the installation accuracy of the bent cap 1, providing a useful reference for the installation control of the precast bent cap of the assembled bridge, and having great popularization and application value.

[0061] Next, a high-precision installation construction method for a precast bent cap in this exemplary embodiment will be further described.

[0062] In an embodiment of the present invention, the specific process of step S1 "Erect the bent cap support system 2. Mark the elevation control points 6 of the splash guard on the pier column 3 according to the bottom elevation of the bent cap 1, and mark multiple bent cap reference control points on the bent cap support system 2 according to the size of the bent cap 1" can be further described in combination with the following description

[0063] As described in the following steps, in S11, temporary supports 210 and an operating platform 200 are erected, and adjusting sand boxes 5 are arranged on the operating platform 200 according to the elevation adjustment requirements of the capping beam 1. Among them, the above-mentioned elevation adjustment requirements of the capping beam 1 specifically mean that after the adjusting sand boxes 5 are adjusted, it is necessary to ensure that the position of the bottom pier column 3 of the capping beam 1 is horizontal, and the starting slope elevations on both sides of the capping beam 1 are accurate.

[0064] As an example, the above-mentioned temporary supports 210 include multiple groups of support frames and a plurality of I-beam crossbeams arranged on the tops of the support frames. The above-mentioned support frames include a plurality of columns 211, and cross braces 212 and diagonal braces 213 arranged between adjacent columns 211. A base plate 214 is provided at the bottom of the columns 211; specifically, a group of the above-mentioned support frames includes four columns 211, a cross brace 212 and a diagonal brace 213 are arranged between two adjacent columns 211, and the four columns 211 form a rectangular support frame. It should be noted that the number of groups and the fixed positions of the support frames are determined according to the actual load of the capping beam 1, and two pier columns 3 are arranged between every two groups of support frames; the above-mentioned operating platform 200 is a plurality of spliced wooden boards laid on the I-beam crossbeams. It should be noted that except for leaving gaps at the positions of the pier columns 3 and the end positions of the capping beam 1 for arranging observation points, other positions are fully covered with wooden boards to ensure construction safety during the construction process.

[0065] As an example, two groups of the above-mentioned adjusting sand boxes 5 are arranged. The two groups of adjusting sand boxes 5 are arranged in parallel on the outer sides of the pier columns 3, with two in each group, a total of four. It should be noted that generally, the four adjusting sand boxes 5 are pairwise flush, the two on the left are flush, and the specific elevation is determined according to the starting slope elevation of the left capping beam (related to the position of the adjusting sand box 5 and the slope of the lower part of the capping beam 1), or it can be designed to be slightly higher than the required elevation in combination with the estimated shrinkage of the sand in the adjusting sand box 5; the two on the right are flush, and the corresponding elevation is determined according to the starting slope elevation of the right capping beam 1 (related to the position of the adjusting sand box 5 and the slope of the lower part of the capping beam), or it can be designed to be slightly higher than the required elevation in combination with the estimated shrinkage of the sand in the adjusting sand box 5. When the starting slopes on the left and right and the positions of the adjusting sand boxes 5 are the same, the four adjusting sand boxes 5 are flush. The adjusting sand boxes 5 are used to adjust the elevation of the capping beam 1; the above-mentioned adjusting sand boxes 5 are cylindrical steel cylinders filled with fine sand, and concrete or steel piers are provided on the fine sand. An opening and closing port for releasing the fine sand is opened at the bottom of the side of the above-mentioned adjusting sand box 5. By releasing the fine sand through the opening and closing port, the concrete or steel pier sinks, so as to achieve the purpose of adjusting the elevation of the capping beam 1.

[0066] As described in the following steps, in S12, elevation control points 6 for the splash guard are marked on the pier columns 3 according to the bottom elevation of the capping beam 1; among them, the elevation control points 6 for the splash guard are respectively marked around the pier columns 3, that is, on the outer sides of the four directions of the pier columns 3, and are located on the same horizontal line, so that the splash guard 13 remains horizontal after installation. The above-mentioned elevation control points 6 for the splash guard are used for installing the splash guard 13 to ensure the accurate installation elevation of the splash guard 13 and further ensure the accurate elevation when the capping beam 1 falls onto the pier column 3.

[0067] As Figure 3 shown, as described in the following steps, S13. Mark the bottom transverse center line 7, the upper edge control point 8 of the center line, and the longitudinal edge control points 9 of the capping beam on the I-beam cross beam of the capping beam support system 2 according to the dimensions of the capping beam 1.

[0068] In a specific implementation, determine the position of the bottom transverse center line 7 of the capping beam according to the transverse bridge length and longitudinal bridge length of the capping beam 1, and determine the upper edge control point 8 of the center line and the longitudinal edge control points 9 of the capping beam according to the length, and mark them correspondingly on the I-beam cross beam for checking the elevation and horizontal position during the installation of the capping beam 1.

[0069] In an embodiment of the present invention, the specific process of step S2 "successively place the splash guard 13 and the adjusting pads 4 according to the elevation control points 6 of the splash guard, check the elevation of the capping beam 1 and conduct the initial lifting of the capping beam 1, and perform mortar bedding after the initial lifting is completed" can be further described in combination with the following description.

[0070] As described in the following steps, S21. Place the splash guard 13 on the edge of the pier column 3 according to the elevation control points 6 of the splash guard, and place a plurality of adjusting pads 4 on the top of the pier column 3; among them, preferably 4 adjusting pads 4 are provided, and the 4 adjusting pads 4 are arranged at intervals, and the top elevation of the splash guard 13 is higher than the top elevation of the adjusting pads 4 by a certain distance.

[0071] It should be noted that the above-mentioned adjusting pads 4 are used to ensure the elevation of the splicing position, and in combination with the elevation of the adjusting sand boxes 5, the overall elevation of the capping beam 1 can be ensured to be controllable. At the same time, in order to ensure that the mortar cushion slurry at the splicing position of the pier column 3 and the capping beam 1 is full, the top elevation of the splash guard 13 can be slightly higher than the top elevation of the adjusting pads 4. Subsequently, relying on the self-weight of the capping beam 1, the splash guard 13 automatically moves down to be flush with the pads. At this time, the bottom elevations of the splash guard 13, the pads, and the capping beam 1 are all at the same horizontal plane.

[0072] As described in the following steps, S22. Slowly place the capping beam 1 on the pier column 3 and the adjusting sand boxes 5, adjust the elevation of the adjusting sand boxes 5, and check the elevation of the capping beam 1 to complete the initial lifting of the capping beam 1.

[0073] As an example, after adjusting the adjusting sand boxes 5, check the transverse bridge elevation and longitudinal bridge elevation of the capping beam 1.

[0074] In a specific implementation, after the dimensions of the front bent cap 1, the positions of multiple reference control points, and the elevation of the adjusting sand box 5 are verified without error, the first trial hoisting of the bent cap 1 is carried out. The hoisting machinery is used to lift and move the bent cap 1 so that the grouting bellows 11 at its bottom are aligned with the reserved steel bars at the upper part of the pier column 3, and then it is slowly and steadily lowered. After the force on the cushion block 4 is adjusted to be stable, the crane is slowly unloaded. The elevation at the adjusting sand box 5 is adjusted by releasing fine sand. After adjustment, the transverse elevation and longitudinal elevation of the bent cap 1 are verified by cooperating with a spirit level, a tower ruler, a level gauge, etc. to ensure that the transverse slope of the bent cap 1 is accurate and the bottom is horizontal in the longitudinal direction. Among them, the allowable deviation of elevation control is ±3 mm.

[0075] As described in the following steps, S23: Install a grout stop pad on the reserved steel bars of the pier column 3, carry out mortar bedding, inject grout into the grout retaining plate 13, and level it. The elevation of the grout surface is the same as that of the built-in adjusting cushion block 4 and slightly higher than that of the adjusting cushion block 4.

[0076] In a specific implementation, after the elevation of the bent cap 1 is verified without error, the bent cap 1 is lifted off, a grout stop pad is installed on the reserved steel bars of the pier column 3 and mortar bedding begins. High-strength non-shrinkage mortar is used for mortar bedding. After the mortar is stirred, it is poured into the grout retaining plate 13 and leveled to complete the mortar bedding.

[0077] In an embodiment of the present invention, the specific process of step S3, "Move the bent cap 1 to a preset distance above the adjusting cushion block 4, respectively verify and adjust the falling position of the bent cap 1 based on multiple bent cap reference control points, and vertically lower the bent cap 1 after verification is correct" can be further described in combination with the following description.

[0078] Specifically, after the trial hoisting of the bent cap 1 is completed and the mortar bedding is completed, the bent cap 1 is officially installed in place.

[0079] As described in the following steps, S31: Move the bent cap 1 to a preset distance above the adjusting cushion block 4; where the preset distance is 1 cm - 2 cm. It should be noted that after moving the bent cap 1 to 1 cm - 2 cm above the adjusting cushion block 4 and stopping, first verify and adjust the horizontal position of the bent cap 1 to ensure the accuracy of the falling position of the bent cap 1.

[0080] As described in the following steps, S32: Respectively verify and adjust the front, rear, left, and right positions of the bent cap 1 based on the transverse center line 7 at the bottom of the bent cap, the control point 8 at the upper edge of the center line, and the longitudinal edge control point 9 of the bent cap.

[0081] As an example, the inner longitudinal center position and transverse edge position of the bent cap 1 are verified based on the inner centerline upper edge control point 8, and the outer longitudinal center position and transverse edge position of the bent cap 1 are verified based on the outer centerline upper edge control point 8; the inner longitudinal edge position of the bent cap 1 is verified based on the inner bent cap longitudinal edge control point 9, and the outer longitudinal edge position of the bent cap 1 is verified based on the outer bent cap longitudinal edge control point 9. Herein, the inner side is the joint side of the segmental bent cap, and the outer side is the opposite side of the segmental bent cap joint side, that is, whether the center and edge positions at both ends of the bent cap 1 are aligned with the bent cap reference control points are respectively verified. If not aligned, fine-tuning is performed based on the bent cap reference control points to ensure the accurate horizontal position and precise falling position of the bent cap 1.

[0082] As described in the following steps, in S33, after verification, the bent cap 1 is vertically lowered and installed.

[0083] In a specific implementation, a lifting machine is used to slowly move the bent cap 1. When the grouting sleeve is aligned with the reserved steel bars of the pier column 3 and steadily descends, when it is about 1 - 2 cm away from the adjusting cushion block 4, a plumb bob is used to check the front-back and left-right positions of the bent cap 1 in the plane in combination with the centerline control points and edge control points set previously to ensure the accurate horizontal position of the bent cap 1, and the allowable error of the axial deviation is ±2 mm. If there is an error, fine-tuning is performed to align it. After confirmation, the bent cap 1 is vertically lowered. After it is stably landed, the crane is unloaded. Then, the installation reference points and relevant data of the bent cap 1 are rechecked. After confirmation, the lifting ropes are removed to complete the installation of the bent cap 1.

[0084] In an embodiment of the present invention, the following steps are further included: the mortar cushion layer of the installed bent cap 1 is cured for 24 hours, and then the corrugated pipe 11 is grouted. It should be noted that according to whether the corrugated pipe 11 is located on the backbone beam of the bent cap or on the base positions on both sides of the backbone beam of the bent cap, there are two grouting methods. One is when the corrugated pipe 11 is located on the base positions on both sides of the backbone beam, grouting is directly carried out from the outlet of the upper corrugated pipe of the bent cap 1; the other is when the corrugated pipe 11 cannot extend out from the backbone beam of the bent cap, grouting (grouting) is carried out through the grouting pipe 10 and the supporting slurry outlet pipe. The slurry outlet pipe is located at the top of the bent cap 1 and is correspondingly arranged with the grouting pipe 10 at the bottom, which is specifically determined according to the actual situation. It can be divided into two steps. In the first step, the grouting pipe 10 grouts upward from the bottom of the bent cap 1. The grouting pipe 10 is arranged on both sides of the pier column 3, eight on one side and six on the other side. In the second step, the corrugated pipe 11 is arranged in the bent cap 1. The inlet of the corrugated pipe 11 is arranged on the upper top surface of the bent cap 1, nine on one side and a total of eighteen on both sides. Grouting starts from the upper corrugated pipe 11 to complete the grouting; the reinforcement bars of the wet joint 12 between multiple segments of the bent cap 1 are tied and concrete is poured. After pouring, the formwork is removed for curing; after curing, prestress tensioning is carried out to connect multiple segments of the bent cap 1 into one body.

[0085] The method for ensuring the installation accuracy of the precast capping beam 1 of the present invention is easy to understand, simple and convenient, easy to master, without adding other additional aids or increasing other costs, and can accurately ensure the installation accuracy of the capping beam 1, providing a useful reference for the installation control of the precast bridge capping beam 1 and having great popularization and application value.

[0086] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-precision installation construction method for precast capping beams, characterized in that, The steps are as follows: Erect the bent cap support system, mark the elevation control points of the baffle on the pier column according to the bottom elevation of the bent cap, and mark multiple bent cap reference control points on the bent cap support system according to the size of the bent cap; Place the baffle and adjusting pads in sequence according to the elevation control points of the baffle, conduct the initial hoisting of the bent cap, adjust and verify the elevation of the bent cap, and perform mortar bedding after the initial hoisting is completed; Move the bent cap to a position at a preset distance above the adjusting pads, respectively verify and adjust the falling position of the bent cap according to multiple bent cap reference control points, and vertically lower the bent cap after verification; After the lowering is completed, recheck the bent cap according to the bent cap reference control points, remove the lifting ropes after verification, and complete the installation of the bent cap.

2. The high-precision installation construction method of the precast capping beam according to claim 1, wherein The steps of erecting the bent cap support system, marking the elevation control points of the baffle on the pier column according to the bottom elevation of the bent cap, and marking multiple bent cap reference control points on the bent cap support system according to the size of the bent cap include: Erect temporary supports and operation platforms, and set adjusting sand boxes on the operation platforms according to the elevation adjustment requirements of the bent cap; Mark the elevation control points of the baffle on the pier column according to the bottom elevation of the bent cap; among them, the elevation control points of the baffle are respectively marked around the pier column; Mark the transverse center line at the bottom of the bent cap, the control point at the upper edge of the center line, and the longitudinal edge control points of the bent cap on the I-beam cross beam of the bent cap support system according to the size of the bent cap.

3. The high-precision installation construction method of the precast capping beam according to claim 2, characterized in that The steps of placing the baffle and adjusting pads in sequence according to the elevation control points of the baffle, conducting the initial hoisting of the bent cap, adjusting and verifying the elevation of the bent cap, and performing mortar bedding after the initial hoisting is completed include: Place the baffle at the edge of the pier column according to the elevation control points of the baffle, and place multiple adjusting pads on the top of the pier column; among them, the top elevation of the baffle is higher than the top elevation of the adjusting pads; Slowly place the bent cap on the pier column and the adjusting sand boxes, adjust the elevation of the adjusting sand boxes, and verify the elevation of the bent cap to complete the initial hoisting of the bent cap; Install a mortar stop pad on the reserved steel bars of the pier column, conduct mortar bedding, inject mortar into the baffle, and level it. Among them, the mortar surface elevation is consistent with the elevation of the built-in adjusting pads and slightly higher than the adjusting pads.

4. The high-precision installation construction method of the precast capping beam according to claim 2, characterized in that, The steps of moving the bent cap to a position at a preset distance above the adjusting pads, respectively verifying and adjusting the falling position of the bent cap according to multiple bent cap reference control points, and vertically lowering the bent cap after verification include: Move the bent cap to a position at a preset distance above the adjusting pads; among them, the preset distance is 1 cm - 2 cm; Respectively verify and adjust the front, rear, left, and right positions of the bent cap according to the transverse center line at the bottom of the bent cap, the control point at the upper edge of the center line, and the longitudinal edge control points of the bent cap; Vertically lower the bent cap after verification.

5. The high-precision installation construction method of the precast capping beam according to claim 3, wherein, The steps of placing the bent cap on the pier column and the adjusting sand boxes, adjusting the elevation of the adjusting sand boxes, and verifying the elevation of the bent cap to complete the initial hoisting of the bent cap include: After adjusting the adjusting sand boxes, verify the elevation of the bent cap in the transverse bridge direction and the elevation of the bent cap in the longitudinal bridge direction.

6. The high-precision installation construction method of the precast bent cap according to claim 4, characterized in that, The steps of verifying the front, rear, left, and right positions of the capping beam respectively based on the horizontal center line at the bottom of the capping beam, the control point at the upper edge of the center line, and the longitudinal edge control points of the capping beam include: Verifying the longitudinal bridge center position and the transverse bridge edge position on the inner side of the capping beam based on the control point at the upper edge of the center line on the inner side, and verifying the longitudinal bridge center position and the transverse bridge edge position on the outer side of the capping beam based on the control point at the upper edge of the center line on the outer side; Verifying the longitudinal bridge edge position on the inner side of the capping beam based on the longitudinal edge control point of the capping beam on the inner side, and verifying the longitudinal bridge edge position on the outer side of the capping beam based on the longitudinal edge control point of the capping beam on the outer side.

7. The high-precision installation construction method of the precast capping beam according to claim 1, characterized in that It further includes: Curing the mortar cushion layer of the installed capping beam for 24 hours, and then grouting the corrugated pipe.

8. The high-precision installation construction method of the precast capping beam according to claim 1, characterized in that, It further includes: Binding steel bars and pouring concrete for the wet joints between multiple sections of the capping beam, and removing the formwork for curing after pouring; After the curing is completed, prestressing tensioning is carried out to connect multiple sections of the capping beam into one body.

9. The high-precision installation construction method of the precast coping beam according to claim 2, characterized in that, The adjusting sand box is a cylindrical steel cylinder filled with fine sand, a concrete or steel pier is provided on the fine sand, and an opening and closing port for releasing the fine sand is arranged at the bottom of the side of the adjusting sand box.

10. The high-precision installation construction method of the precast coping beam according to claim 2, wherein, The temporary support includes multiple groups of support frames and a plurality of I-beam crossbeams arranged on the tops of the support frames. The support frames include a plurality of columns and cross braces and diagonal braces arranged between adjacent columns; the operation platform is a plurality of spliced wooden boards laid on the I-beam crossbeams.

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