A construction method for rapid matching of steel box girders

Abstract

This invention discloses a construction method for rapidly matching steel box girders, comprising the following steps: Step 1: Pre-assemble the steel box girder along a long line according to the pre-assembly alignment and monitoring requirements; Step 2: Mark five pairs of marker lines on the top plate and both sides of the steel box girder on both sides of each circumferential joint, and measure and record the spacing value of each pair of marker lines; Step 3: During actual installation, after the stay cables of the (N-1)th segment of the steel box girder are tensioned, measure the elevation and axis of the installed steel box girder; calculate the elevation and axis correction amount and the spacing correction value of the five pairs of marker lines during the installation of the Nth segment of the steel box girder; Step 4: Lift the Nth segment of the steel box girder for initial matching; Step 5: Adjust the spacing of the five pairs of marker lines according to the calculated spacing correction value, and weld them, then tension the stay cables of the Nth segment of the steel box girder; Step 6: Repeat steps 3 to 5; This invention has the advantages of being unaffected by manufacturing errors, having a short construction cycle, and high matching efficiency.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology, specifically relating to a construction method for rapidly matching steel box girders. Background Technology

[0002] With the rapid development of long-span bridge construction technology and steel structure manufacturing in my country, a large number of completed and under-construction cable-stayed bridges have adopted steel structures for their main girder construction. Steel box girders, due to their superior load-bearing performance, strong spanning capacity, and convenient construction, are widely used in long-span cable-stayed bridges.

[0003] In the construction of the superstructure of cable-stayed bridges, steel box girders are typically manufactured as a whole, pre-assembled along a long line, and then hoisted in sections. At the bridge site, the installation accuracy of the steel box girders is crucial to the final bridge alignment. Traditional steel girder matching and installation generally employs measurement control, which involves measuring the elevation and axis of the pre-installed steel box girder, calculating the deviation from theoretical values, and then determining the elevation and axis for matching the steel box girder during installation.

[0004] Chinese invention patent (application number CN202110934884.8) discloses a long-span, high-low tower, double-cable-stayed bridge and its construction method. The method includes: pouring concrete for the cast-in-place sections on the high and low tower sides; constructing the steel-concrete composite section on the high tower side and temporarily locking it to the auxiliary pier on the high tower side; constructing the steel box girder of the side span on the high tower side using the jacking method; assembling a girder erection crane at the front end of the steel box girder on the high tower side, and assembling another girder erection crane at the front end of the steel-concrete composite section on the middle span side of the low tower; symmetrically and synchronously hoisting and assembling the middle span cantilever section on both sides of the bridge tower until the closure section. The measurement and matching effect is greatly affected by manufacturing errors, sunlight, and temperature gradients, requiring nighttime construction. Nighttime matching work is time-consuming and intensive.

[0005] Chinese invention patent (application number CN202010380038.1) discloses a method for the overall assembly of ultra-wide segmented steel box girders, which relates to the field of steel box girder assembly technology. It includes plate unit manufacturing and plate welding, beam segment matching welding, pre-assembly, and pre-assembly inspection. The beam segments are welded in the following order: bottom plate, transverse diaphragms, intermediate top plate, initial positioning inner web plate and anchor web plate, remaining top plates, secondary positioning anchor web plate, intermediate crossbeams, and cantilever blocks. Assembly and welding are performed segment by segment in a three-dimensional, stepped manner. During pre-assembly, the influence of weld circumferential shrinkage and beam segment compression caused by cable force on the length must be considered. The cumulative total length and error of the previous pre-assembly should be corrected in the next assembly. The measurement and matching effect is greatly affected by the manufacturing error of the beam segments, sunlight, and temperature gradient, requiring nighttime construction. Nighttime matching work is longer and more intensive.

[0006] The problem with existing technologies is that the traditional measurement and matching effect is greatly affected by manufacturing errors, sunlight and temperature gradients, and construction needs to be carried out at night. After the steel box girder is lifted during the day, the site is in a state of idle work, and the measurement and matching process requires repeated measurement and adjustment until it is in place. Nighttime matching work is time-consuming, inefficient and arduous. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the prior art by providing a construction method for quickly matching steel box girders, which has the advantages of being unaffected by manufacturing errors, having a short construction period, and high matching efficiency.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a construction method for rapidly matching steel box girders, comprising the following steps:

[0009] Step 1: Construction preparation; Based on the pre-assembly alignment, perform long-line pre-assembly of the steel box girder; Measure and adjust the alignment of the pre-assembled steel girder to ensure that the alignment meets the monitoring requirements;

[0010] Step 2: Draw marking lines to determine the relative positional relationship between each pair of adjacent steel box girders; draw five pairs of marking lines on the top plate and both sides of the steel box girder on both sides of each circumferential joint, and on both sides of the bottom plate, and measure and record the spacing value of each pair of marking lines.

[0011] Step 3: During actual installation, measurement work is carried out before lifting the Nth steel box girder; the Nth steel box girder is the steel box girder to be installed. After the stay cables of the N-1th steel box girder are tensioned, the elevation and axis of the installed steel box girder are measured; based on the measurement results, the elevation and axis correction amount of the Nth steel box girder during installation are calculated, and the spacing correction value of the five pairs of marker lines is calculated.

[0012] Step 4: Lift the Nth steel box girder and perform initial matching; After the Nth steel box girder is lifted into place, adjust the Nth steel box girder so that the axis and elevation of the Nth steel box girder and the N-1th steel box girder are aligned respectively.

[0013] Step 5: Adjust the spacing of the five pairs of marker lines according to the calculated spacing correction value, and weld them. Then hang the cable-stayed cable of the Nth segment of the steel box girder and tension it once. Finally, move the bridge deck crane forward and tension the cable-stayed cable of the Nth segment of the steel box girder a second time.

[0014] Step Six: Repeat Steps Three through Five.

[0015] In the above scheme, in step one, the steel box girder is pre-assembled according to the pre-assembly alignment. The pre-assembly alignment is key data to ensure the final bridge alignment. The pre-assembly alignment is calculated and analyzed in advance, and the monitoring instructions guide the construction. Simultaneously, the long-line pre-assembly method is adopted to ensure the smoothness of the pre-assembly alignment of the steel box girder and to meet monitoring requirements. After pre-assembly, the steel girder alignment is measured. If the measured data has a large error compared to the theoretical data calculated by the monitoring unit, the pre-assembly of the steel girder needs to be readjusted; if the error is small, no adjustment is needed, and it can be recorded for correction in subsequent construction. In step two, the steel girder is lifted and matched during construction. In practice, this involves determining the spatial position and relative positional relationship of the steel box girders. A circumferential joint is left between adjacent steel box girders. Marking lines is used to determine the relative positional relationship between the steel box girders. The spacing between the corresponding marking lines between any two beam segments does not need to be a fixed value, but it must be recorded accurately. As long as the spacing of these five pairs of marking lines corresponds to the values ​​used during construction and marking, the relative positional relationship between the two beam segments can be determined. In practice, the same standard spacing value can be used for ease of construction and recording. The three pairs of marking lines on the top slab are used to determine the relative position in planar plane, in conjunction with the two pairs on the bottom slab. The marker lines can determine the relative positions of the facades; in step three, the Nth segment of the steel box girder is the steel box girder to be installed, and the (N-1)th segment is the preceding segment of the steel box girder to be installed. The stay cables of the (N-1)th segment have been installed after secondary tensioning. The installation parameters of the Nth segment are calculated by measuring the elevation and axis of the installed steel box girders preceding the Nth segment to ensure a smooth alignment. If there is a deviation between the axis of the installed steel box girder and the theoretical axis, adjustments will be made during subsequent steel box girder construction, gradually correcting the deviation once or multiple times; if there is no deviation in the installed steel box girder... That is, the correction amount is 0, and the spacing correction value is the mark line spacing value recorded in the re-measurement; in step four, the initial matching of the Nth steel box girder is carried out so that the axis and elevation of the Nth steel box girder and the N-1th steel box girder are aligned; in step five, according to the calculated installation parameters of the Nth steel box girder, the spacing of the five pairs of mark lines is adjusted according to the monitoring instructions, and the circumferential joint between the Nth steel box girder and the N-1th steel box girder is welded. The cable stays of the Nth steel box girder are hung and tensioned to complete the matching installation of the Nth steel box girder. Steps three to five are repeated to complete the matching installation of the remaining steel box girders.

[0016] The key to matching lies in restoring the pre-assembled alignment given by the monitoring system during the hoisting and matching construction. This scheme uses the marker line method to determine the relative positions of the steel box girders. This method is unaffected by manufacturing (shape) errors in the steel box girder segments during matching and installation, better ensuring a smooth installation alignment. Matching construction is not limited by ambient temperature, offers high accuracy, reduces nighttime workload, and improves construction efficiency. The marker line method can be used to measure spacing with a steel ruler, and even with repeated adjustments, it is still more convenient and labor-saving than traditional measurement matching methods.

[0017] Furthermore, in step two, the spacing between each pair of marker lines is adjusted to a range of 200mm to 500mm.

[0018] The spacing between each pair of marking lines can be determined according to the actual structure of the bridge deck. The spacing between each pair of marking lines is adjusted to 200mm to 500mm to facilitate spacing measurement during matching construction.

[0019] Furthermore, in step three, the elevation and axis of at least the N-1, N-2, and N-3 steel box girder segments of the first three segments of the Nth steel box girder must be measured.

[0020] By measuring the elevation and axis of at least the first three beam segments, the installation parameters are calculated to guide the matching construction of the Nth steel box girder, predicting that the alignment angle is appropriate, the transition is smooth, and driving safety is guaranteed.

[0021] Furthermore, in step three, the formula for calculating the spacing correction value of the marker lines is as follows:

[0022] LTi=Li+Δxi;

[0023] Wherein, Li is the measured value of the spacing between the two marker lines in step two, Δxi is the spacing adjustment amount, and the value range of Δxi is 0 to 10 mm; when the axis correction amount is 0, Δxi = 0.

[0024] The upper limit of the spacing adjustment Δxi depends on the axis correction amount and the weld width. If the value is too large, it means that the weld is too wide, which is not conducive to welding construction and affects the weld quality.

[0025] When Δxi is 0, the spacing correction value of the five pairs of marker lines is the actual spacing value measured in step two, indicating that there is no deviation in the axis of the installed steel box girder.

[0026] Furthermore, when the axis correction amount is not zero, the formula for calculating the spacing adjustment amount is as follows:

[0027] Δxi=Ai*YTi / X,

[0028] Where Ai is the axial correction amount of a single steel box girder, X is the length of the Nth steel box girder segment, and YTi is the distance from the marker point to the side of the Nth steel box girder segment in the axial offset direction.

[0029] During actual construction, the axial correction amount Ai is determined based on the actual measured deviation of the Nth steel box girder relative to the pre-assembled alignment of the preceding steel box girder segments or the N-1th steel box girder segment. YTi is the distance from the marker point to the side of the Nth steel box girder segment in the axial offset direction. That is, when the Nth steel box girder segment shifts to the left, YTi is the distance from the marker point to the left side of the Nth steel box girder segment; when the Nth steel box girder segment shifts to the right, YTi is the distance from the marker point to the right side of the Nth steel box girder segment.

[0030] Furthermore, the marking line is cross-shaped or T-shaped.

[0031] It facilitates the measurement of the spacing between each pair of marking lines and makes it easier to axially align adjacent steel box girders during initial matching.

[0032] Furthermore, in step three, the axial deviation of a single steel box girder section shall not exceed 5mm.

[0033] If the axial deviation of the installed steel box girder exceeds 5mm, it can be adjusted multiple times in multiple sections of the steel box girder; excessive correction of a single section can easily lead to the formation of angles between steel box girders.

[0034] Furthermore, in step five, after adjusting the spacing of the five pairs of marker lines according to the monitoring instructions, the misalignment between the Nth steel box girder and the previous steel box girder is first adjusted, marking is performed, and then welding is carried out.

[0035] Furthermore, after the adjustment, the misalignment of the front edge should not exceed 20mm.

[0036] The adjusted misalignment of the front edge is no more than 20mm, which facilitates welding construction and ensures the quality of the weld.

[0037] Furthermore, in step two, the three pairs of marking lines on the top plate are numbered T1 to T3, and the two pairs of marking lines on the bottom plate are numbered B1 to B2.

[0038] The five pairs of marker lines are numbered separately to facilitate data recording and subsequent calculations.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] (1) The measurement error of the marking line is much smaller than the manufacturing error of the steel beam segment. That is, the relative position relationship of the steel box girder is determined by the marking line method. The matching installation is not affected by the manufacturing (shape) error of the steel beam segment, which improves the matching accuracy and matching efficiency.

[0041] (2) The present invention takes into account the relative positional relationship of adjacent steel box girders and improves the installation line smoothness of steel box girders by correcting the spacing of each marking line;

[0042] (3) The steel box girder matching method provided by the present invention matches adjacent steel box girders by marking lines. It is not restricted by ambient temperature and can be carried out during the daytime. This greatly reduces the nighttime construction time and the amount of measurement work during matching and installation, reduces the labor intensity of workers, allows for flexible construction time, and shortens the construction cycle. Attached Figure Description

[0043] Figure 1 This is a top view schematic diagram of the steel box girder in Embodiment 1 of the present invention;

[0044] Figure 2 This is a schematic front view of the steel box girder in Embodiment 1 of the present invention;

[0045] Figure 3 for Figure 2 AA section view in the middle;

[0046] Figure 4 This is a schematic diagram of the marker line structure in Embodiment 1 of the present invention;

[0047] Figure 5 This is a schematic diagram illustrating the calculation of the spacing correction value of the marking lines on the top plate of the steel box girder in Embodiment 1 of the present invention;

[0048] Figure 6 This is a schematic diagram of the marker line structure in Embodiment 2 of the present invention;

[0049] In the diagram: 1. Steel box girder segment N-1; 2. Steel box girder segment N; 3. Marker line; 31. Marker line T1; 32. Marker line T2; 33. Marker line T3; 34. Marker line B1; 35. Marker line B2; 4. Sample punching point. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Example 1

[0052] like Figure 1-5 As shown, a construction method for quickly matching steel box girders includes the following steps:

[0053] Step 1: Construction preparation; Based on the pre-assembly alignment, perform long-line pre-assembly of the steel box girder; Measure and adjust the alignment of the pre-assembled steel girder to ensure that the alignment meets the monitoring requirements;

[0054] Step 2: Draw marking lines 3 to determine the relative positional relationship between each pair of adjacent steel box girders; draw five pairs of marking lines 3 on the middle and sides of the top plate and the sides of the bottom plate of the steel box girders on both sides of each circumferential joint, and measure and record the spacing value of each pair of marking lines 3.

[0055] Step 3: During actual installation, the measurement work is carried out before the lifting of the Nth steel box girder 2; the Nth steel box girder 2 is the steel box girder to be installed. After the tensioning of the N-1th steel box girder 1 is completed, the elevation and axis of the installed steel box girder are measured; based on the measurement results, the elevation and axis correction amount of the Nth steel box girder 2 during installation are calculated, and the spacing correction value of the five pairs of marker lines 3 is calculated.

[0056] Step 4: Lift the Nth steel box girder 2 and perform initial matching; after the Nth steel box girder 2 is lifted into place, adjust the Nth steel box girder 2 to align its axis and elevation with the N-1th steel box girder 1 respectively;

[0057] Step 5: Adjust the spacing of the five pairs of marker lines 3 according to the calculated spacing correction value, and weld them. Then hang the cable-stayed cable of the Nth segment of the steel box girder 2 and tension it once. Finally, move the bridge deck crane forward and tension the cable-stayed cable of the Nth segment of the steel box girder 2 a second time.

[0058] Step Six: Repeat Steps Three through Five.

[0059] In the above scheme, in step one, the steel box girder is pre-assembled according to the pre-assembly alignment given by the monitoring instructions. The pre-assembly alignment is key data to ensure the alignment of the completed bridge. The long-line pre-assembly method ensures the smoothness of the pre-assembled steel box girder alignment and meets monitoring requirements. After pre-assembly, the steel girder alignment is measured. If the measured data has a large error compared to the theoretical data calculated by the monitoring unit, the pre-assembly of the steel girder needs to be readjusted. If the error is small, no adjustment is needed, and it can be recorded for correction during subsequent construction. In step two, the steel girder is lifted and matched for installation. In practice, this involves determining the spatial position of the steel box girder. The relative positional relationship between adjacent steel box girders is determined by marking lines 3. A circumferential joint is left between adjacent steel box girders. The spacing between these marking lines 3 between any two beam segments does not need to be a fixed value, but it must be recorded accurately. As long as the spacing of these five pairs of marking lines corresponds to the values ​​used during construction, the relative positional relationship between the two beam segments can be determined. In practice, the same standard spacing value can be used for ease of construction and recording. The three pairs of marking lines 3 on the top slab are used to determine the relative position in the plane, which, together with the two pairs of marking lines 3 on the bottom slab, can... Determine the relative positions of the facades; in step three, the Nth segment steel box girder 2 is the steel box girder to be installed, and the N-1th segment steel box girder 1 is the preceding segment of the steel box girder to be installed. The N-1th segment steel box girder 1 has been installed after secondary tensioning. The installation parameters of the Nth segment steel box girder 2 are calculated by measuring the elevation and axis of the installed steel box girder before the Nth segment steel box girder 2 to ensure a smooth alignment. If there is a deviation between the axis of the constructed steel box girder segment and the theoretical axis, it will be adjusted in the subsequent steel box girder construction, gradually correcting the deviation once or multiple times; if there is no deviation in the installed steel box girder... That is, the correction amount is 0, and the spacing correction value is the mark line spacing value recorded in the re-measurement; in step four, the initial matching of the Nth steel box girder 2 is carried out, and the axis and elevation of the Nth steel box girder 2 are adjusted; in step five, according to the calculated installation parameters of the Nth steel box girder 2, the spacing of the five pairs of mark lines 3 is adjusted according to the monitoring instructions, and the circumferential joint between the Nth steel box girder 2 and the N-1th steel box girder 1 is welded. The cable stays of the Nth steel box girder 2 are hung and tensioned to complete the matching installation of the Nth steel box girder 2. Steps three to five are repeated to complete the matching installation of the remaining steel box girders.

[0060] The upstream of the top plate of the steel box girder is marked with T1 mark line 31, the middle of the top plate is marked with T2 mark line 32, the downstream of the top plate is marked with T3 mark line 33, the upstream of the bottom plate of the steel box girder is marked with B1 mark line 34, and the downstream of the bottom plate is marked with B2 mark line 35.

[0061] In step two, first mark the sampling point 4, then draw cross-shaped marker lines 3, with a spacing of 300mm between each pair of marker lines 3. Record the spacing of marker lines 3 for each beam segment separately, in the following format: the actual spacing of marker lines 3 on the upstream side of the top plate of steel box girder segment 6 is recorded as 6~T1, and on the downstream side of the bottom plate as 6~B2. When adjusting the spacing of marker lines 3 in step five, pay attention to the width of the weld seams of the top and bottom plates and the web plate. In step five, the spacing of marker lines 3 can be adjusted using conventional construction machinery and equipment such as bridge deck cranes, jacks, and hand-operated hoists.

[0062] The key to matching lies in restoring the pre-assembled alignment given by the monitoring system during the hoisting and matching construction. This scheme uses the marker line method to determine the relative positions of the steel box girders. This method is unaffected by manufacturing (shape) errors in the steel beam segments during matching and installation, better ensuring a smooth installation alignment. Matching construction is not limited by ambient temperature, offers high accuracy, reduces nighttime workload, and improves construction efficiency. The marker line method can be used to measure spacing with a steel ruler, and even with repeated adjustments, it is still more convenient and labor-saving than traditional measurement and matching methods.

[0063] Simultaneously marking lines 3 on both the top and bottom surfaces is necessary to ensure the relative positional relationship of adjacent steel beams. Three pairs of marking lines 3 on the top plate determine the relative planar position, while two pairs on the bottom plate determine the relative elevation position. If only marking lines 3 are set on the top plate, it cannot be guaranteed that the front end of the Nth steel box girder meets the elevation requirements. Construction errors are unavoidable; steel box girders have manufacturing (dimensional) errors and measurement errors, and marking lines 3 also have marking errors. For example, the theoretical spacing of marking lines 3 is 300mm, but the actual marking distance may have an error, with the measured distance reading being 299mm. In this case, the baseline value for the spacing of this pair of marking lines 3 would be 299.5mm. As long as the actual spacing after marking is recorded accurately, it can serve as the data basis for subsequent construction.

[0064] Furthermore, in step two, the three pairs of marking lines 3 on the top plate are numbered T1 to T3, and the two pairs of marking lines 3 on the bottom plate are numbered B1 to B2.

[0065] The five pairs of marker lines are numbered separately to facilitate data recording and subsequent calculations.

[0066] Furthermore, in step two, the spacing between each pair of marker lines 3 is adjusted to a range of 200mm to 500mm.

[0067] The spacing between each pair of marking lines can be determined according to the actual structure of the bridge deck. The spacing between each pair of marking lines is adjusted to 200mm to 500mm to facilitate spacing measurement during matching construction.

[0068] Furthermore, in step three, the elevation and axis of at least the first three segments of the Nth segment of the steel box girder 2—the N-1th segment of the steel box girder 1, the N-2nd segment of the steel box girder, and the N-3rd segment of the steel box girder—are measured.

[0069] By measuring the elevation and axis of at least the first three beam segments, installation parameters are calculated to guide the matching construction of the Nth steel box girder 2, predicting a moderate angle and smooth alignment to ensure driving safety. In this embodiment, the alignment is predicted by measuring the first four steel box girder segments of the Nth steel box girder 2, thus guiding the installation of the Nth steel box girder 2.

[0070] Furthermore, in step three, the formula for calculating the spacing correction value of the marker lines is as follows:

[0071] LTi=Li+Δxi;

[0072] Wherein, Li is the measured value of the spacing between the two marker lines in step two, Δxi is the spacing adjustment amount, and the value range of Δxi is 0 to 10 mm; when the axis correction amount is 0, Δxi = 0.

[0073] The upper limit of the spacing adjustment Δxi depends on the axis correction amount and the weld width. If the value is too large, it means that the weld is too wide, which is not conducive to welding construction and affects the weld quality.

[0074] When Δxi is 0, the spacing correction value of the five pairs of marker lines 3 is the actual spacing value measured in step two, indicating that there is no deviation in the axis of the installed steel box girder.

[0075] Furthermore, when the axis correction amount is not zero, the formula for calculating the spacing adjustment amount is as follows:

[0076] Δxi=Ai*YTi / X,

[0077] Where Ai is the axial correction amount of a single steel box girder, X is the length of the Nth steel box girder segment, and YTi is the distance from the marker point to the side of the Nth steel box girder segment in the axial offset direction.

[0078] During actual construction, the axial correction amount Ai is determined based on the actual measured deviation of the steel box girder 1 relative to the pre-assembled alignment of the preceding steel box girder 2 or the steel box girder 1 of the N-1th segment. YTi is the distance from the marker point to the side of the steel box girder 2 in the axial offset direction. That is, when the steel box girder 2 of the Nth segment shifts to the left, YTi is the distance from the marker point to the left side of the steel box girder 2 of the Nth segment. When the steel box girder 2 of the Nth segment shifts to the right, YTi is the distance from the marker point to the right side of the steel box girder 2 of the Nth segment.

[0079] In this embodiment, the axis correction value in step three is calculated as follows:

[0080] For example, the downstream deviation of the axis of steel box girder segment N-1 near the tower end is 5mm, and the downstream deviation of the axis of the far tower end is 9mm, with a single-segment offset of 4mm. If no correction adjustment is made, and the relative positions of the two adjacent steel box girder segments are matched, then the downstream deviation of the axis of steel box girder segment N at the far tower end (front point) is 9+4=13mm. Considering the weld width, let the target value of the axis deviation of steel box girder segment N at the far tower end be 9mm, that is, the axis correction amount Ai is 4mm.

[0081] LT1=L1+Δx1; Δx1=4mm*(YT1 / X)

[0082] LT3=L3+Δx3; Δx3=4mm*(YT3 / X)

[0083] Wherein: LT1 and LT3 are the spacing correction values ​​of T1 marker lines 31 and T3, respectively; L1 and L3 are the actual measured spacing values ​​of T1 marker lines 31 and T3 in step two, both of which are 300mm; Δx1 and Δx3 are the spacing adjustment amounts of T1 marker lines 31 and T3, respectively; X and Y are the segment length and beam width of the standard section of the steel box girder, respectively, X is 16m and Y is 32m; YT1 is the distance of T1 marker line 31 from the side of the steel box girder, YT1 is 4m. In the embodiment, T1 marker lines 31 and T3 marker lines 33 are symmetrically arranged, YT3 = Y - YT1.

[0084] The calculations yielded: Δx1 = 1 mm, LT1 = 301 mm; Δx3 = 7 mm, LT3 = 307 mm;

[0085] Based on the above calculations, after the initial alignment of the adjacent steel box girder axes and elevations in step four, beam matching can be performed according to the corrected calculation values ​​based on the spacing of marker line 3, unaffected by ambient temperature and manufacturing errors of the steel box girder. Similarly, the spacing values ​​of marker line 3 on the base plate are calculated to determine the relative positions of the facades.

[0086] Furthermore, the marker line 3 is cross-shaped.

[0087] It facilitates the measurement of the spacing between each pair of marker lines 3, and also facilitates the axial alignment of each pair of marker lines 3.

[0088] Furthermore, in step three, the axial deviation of a single steel box girder section shall not exceed 5mm.

[0089] If the axial deviation of the installed steel box girder exceeds 5mm, it can be adjusted multiple times in multiple sections of the steel box girder; excessive correction of a single section can easily lead to the formation of angles between steel box girders.

[0090] Furthermore, in step five, after adjusting the spacing of the five pairs of marker lines 3 according to the monitoring instructions, the misalignment of the Nth steel box girder 2 and the previous steel box girder is first adjusted, marking is performed, and then welding is carried out.

[0091] Furthermore, after the adjustment, the misalignment of the front edge should not exceed 20mm.

[0092] It facilitates welding construction and ensures the quality of weld seams.

[0093] Example 2

[0094] like Figure 6 As shown, this embodiment presents a construction method for rapidly matching steel box girders, which is further optimized based on Embodiment 1:

[0095] Furthermore, the marker line 3 is T-shaped.

[0096] It facilitates the measurement of the spacing between each pair of marker lines 3, and makes it easy to axially align adjacent steel box girders during initial matching.

[0097] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A construction method for rapidly matching steel box girders, characterized in that, Includes the following steps: Step 1: Construction preparation; Based on the pre-assembly alignment, perform long-line pre-assembly of the steel box girder; Measure and adjust the alignment of the pre-assembled steel girder to ensure that the alignment meets the monitoring requirements; Step 2: Mark the lines to determine the relative position of each pair of adjacent steel box girders; mark five pairs of lines on the top plate and both sides of the top plate and the bottom plate of the steel box girders on both sides of each circumferential joint, and measure and record the spacing of each pair of lines. Step 3: During actual installation, the measurement work is carried out before the Nth steel box girder is lifted; the Nth steel box girder is the steel box girder to be installed. After the stay cables of the N-1th steel box girder are tensioned, the elevation and axis of the installed steel box girder are measured; based on the measurement results, the elevation and axis correction amount of the Nth steel box girder during installation are calculated, and the spacing correction value of the five pairs of marker lines is calculated. The formula for calculating the spacing correction value of the marking lines is as follows: LTi = Li + Δxi; Wherein, Li is the measured value of the spacing between the two marker lines in step two, Δxi is the spacing adjustment amount, and the value of Δxi ranges from 0 to 10 mm; when the axis correction amount is 0, Δxi = 0; When the axis correction amount is not zero, the formula for calculating the spacing adjustment amount is as follows: Δxi=Ai*YTi / X, Where Ai is the axial correction amount of a single steel box girder, X is the length of the Nth steel box girder, and YTi is the distance from the marker point to the side of the Nth steel box girder in the axial offset direction; the axial correction amount Ai is determined based on the actual measured deviation value of the Nth steel box girder relative to the pre-assembled alignment of the preceding steel box girder segments or the N-1th steel box girder segment. Step 4: Lift the Nth steel box girder and perform initial matching; After the Nth steel box girder is lifted into place, adjust the Nth steel box girder so that the axis and elevation of the Nth steel box girder and the N-1th steel box girder are aligned respectively. Step 5: Adjust the spacing of the five pairs of marker lines according to the calculated spacing correction value, then hang the stay cables of the Nth segment of the steel box girder and tension them once. Finally, move the bridge deck crane forward and tension the stay cables of the Nth segment of the steel box girder a second time. Step 6: Repeat steps 3 through 5.

2. The construction method for rapid matching steel box girders according to claim 1, characterized in that, In step two, the spacing between each pair of marker lines is adjusted to a range of 200mm to 500mm.

3. The construction method for rapid matching steel box girders according to claim 1, characterized in that, In step three, at least the elevation and axis of the first three steel box girder segments N-1, N-2, and N-3 must be measured.

4. The construction method for rapid matching steel box girders according to claim 1, characterized in that, The marking line is either cross-shaped or T-shaped.

5. The construction method for rapid matching steel box girders according to claim 1, characterized in that, In step three, the axial deviation of a single steel box girder section shall not exceed 5mm.

6. The construction method for rapid matching steel box girders according to claim 1, characterized in that, In step five, after adjusting the spacing of the five pairs of marker lines according to the monitoring instructions, first adjust the misalignment of the Nth steel box girder and the previous steel box girder before marking, and then weld.

7. The construction method for rapid matching steel box girders according to claim 6, characterized in that, After adjustment, the misalignment of the front edge should not exceed 20mm.

8. The construction method for rapid matching steel box girders according to claim 1, characterized in that, In step two, the three pairs of marking lines on the top plate are numbered T1~T3, and the two pairs of marking lines on the bottom plate are numbered B1~B2.

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