Construction method of corrugated beam steel guardrail

Abstract

The present application relates to the wave beam steel guardrail construction method, belongs to the bridge engineering field. In the prior art, when the bridge wave beam steel guardrail is constructed, the positioning accuracy of the curved bridge span is insufficient, the installation deviation of the column is large, the stability of the wave beam splicing and the bracket connection is poor, and the overall protection performance of the guardrail is affected. The present application sets the pre-bias distance for the curved bridge span with the curvature radius ≤800 meters by setting out the bridge design reference point; the column posture is finely adjusted to the bidirectional deviation ≤1mm by using three-dimensional laser scanning, and the embedded bolt is tightened in stages; when the wave beam is spliced on the ground, the bolt is tightened symmetrically twice; after the wave beam is hoisted to the bracket, the hydraulic jack is used to adjust the line shape and tighten the bracket bolt. The method can improve the construction accuracy and structural stability of the bridge wave beam steel guardrail, and is mainly used for the construction and installation of the wave beam steel guardrail in the bridge engineering.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology. More specifically, this invention relates to a method for constructing corrugated beam steel guardrails. Background Technology

[0002] In bridge engineering, corrugated beam steel guardrails are crucial for ensuring traffic safety, and their construction precision directly impacts their protective performance and service life. Currently, a prominent problem in the construction of corrugated beam steel guardrails for bridges is insufficient overall construction precision, making it difficult to meet design requirements and actual usage needs. This problem is particularly evident in the construction of curved bridge spans. Traditional layout methods often rely on manual operation of total stations, only marking the center points of the posts based on the design spacing, without considering the curvature of the curved bridge span. Since the guardrails in curved bridge spans need to naturally bend with the bridge alignment, and traditional methods lack targeted pre-deflection compensation measures, deviations occur between the installed post positions and the theoretical positions, leading to uneven alignment after subsequent corrugated beam splicing. The smaller the curvature of the curve segment, the more significant this deviation accumulates, not only affecting the aesthetics of the guardrail but also causing uneven stress on the guardrails when vehicles are driving, increasing the risk of localized damage. Balancing construction efficiency and precision, developing scientific step-by-step operation specifications, and achieving precise pre-deflection compensation for curved bridge spans are all long-standing challenges in solving these problems. Summary of the Invention

[0003] Another objective of this invention is to provide a construction method for corrugated beam steel guardrails. Existing bridge corrugated beam steel guardrail construction lacks overall precision. The curved bridge spans suffer from positioning deviations due to the lack of pre-offset compensation, resulting in large deviations in column installation and affecting the guardrail's protective performance and lifespan.

[0004] To achieve these objectives and other advantages according to the present invention, a method for constructing a corrugated beam steel guardrail is provided, comprising the following steps:

[0005] Step 1: Bridge deck benchmark layout and pre-compensation: Using the bridge design benchmark as the benchmark, use a total station to mark the theoretical column center point on the bridge deck crash barrier or guardrail base according to the design spacing. For curved bridge spans with a curvature radius ≤ 800 meters, determine the pre-offset distance pointing to the center of the curve according to the curvature radius and compensation distance comparison table, and mark the pre-offset column installation point at the layout point.

[0006] Step 2, 3D Laser Reference Anchoring Fine Adjustment: At the column installation point, initially align the anchoring flange at the bottom of the column with the pre-embedded bolts in the base; set up a 3D laser scanner to establish a unified digital reference plane including the longitudinal and transverse slopes of the bridge deck; fix a laser target on the side of the column to provide real-time feedback on the deviation values ​​between the column and the design position in the longitudinal and transverse directions; when the deviation value in the longitudinal or transverse direction is >2mm, adjust the column posture until the bidirectional deviation is ≤1mm; tighten the pre-embedded bolts symmetrically in three levels according to the design torque values ​​of 30%, 60%, and 100%; after each level of tightening, let it stand for 1 minute and check the deviation value; after the column is fixed, install the bracket at the design elevation position, and temporarily tighten the bracket connecting bolts with 60% of the design torque;

[0007] Step 3, Corrugated beam splicing: Splice the corrugated beam on the ground. When splicing, use a digital torque wrench to tighten the splicing bolts in two stages. The first stage is pre-tightened to 40% of the design torque value. After standing for 5 minutes, tighten the bolts a second time to 100% of the design torque in a symmetrical alternating sequence from the middle of the span to both ends.

[0008] Step 4, Guardrail Installation: Hoist the assembled corrugated beam to the bracket support position, so that the bottom of the corrugated beam falls into the bracket. Use a hydraulic jack to apply a lateral adjustment force of ≤5kN to the corrugated beam to adjust the beam's alignment. Tighten the connecting bolts of the bracket to 100% of the design torque. The corrugated beam steel guardrail construction is now complete.

[0009] Preferably, the curvature radius and compensation distance correspondence table is used, with the pre-offset distance value increasing in a decreasing gradient according to the curvature radius. The specific correspondence is as follows:

[0010] A curvature radius of 800m corresponds to a pre-offset distance of 10mm, a curvature radius of 500m corresponds to a pre-offset distance of 18mm, a curvature radius of 300m corresponds to a pre-offset distance of 25mm, and a curvature radius ≤200m corresponds to a pre-offset distance of 35mm.

[0011] For intermediate curvature radius values ​​not listed, the pre-offset distance is calculated using linear interpolation.

[0012] d=d1+(R-R1)(d2-d1) / (R2-R1)

[0013] Where R is the actual radius of curvature, R2 and R1 are adjacent radius values ​​in the reference table and R1 < R < R2, d1 is the pre-offset distance corresponding to R1, and d2 is the pre-offset distance corresponding to R2.

[0014] Preferably, in step four, after the bottom of the corrugated beam falls into the bracket, a rubber elastic pad is inserted into the gap between the web of the corrugated beam and the side wall of the bracket.

[0015] Preferably, in step four, the connecting bolts of the bracket are tightened to 100% of the design torque. The bolts are then passed through the bracket, the rubber elastic pad, and the corrugated beam web in sequence for fastening. During fastening, a digital torque wrench is used to tighten the bolts symmetrically in three stages at 30%, 60%, and 100% of the design torque values, with a 2-minute interval between each tightening.

[0016] Preferably, a horizontal reciprocating load simulating wind vibration or bridge deck vibration is applied to the installed guardrail section. The amplitude of the simulated wind vibration or bridge deck vibration is ±2mm, the frequency is 0.5-1Hz, and the duration is 120 seconds. During the load application process, the change in bolt torque at the connection between the bracket and the column is monitored in real time. If the torque attenuation at any monitoring point is greater than 5% of the design torque value, the bolt at that point needs to be retightened to 100% of the design torque.

[0017] Preferably, in step one, for curved bridge spans with a curvature radius ≤ 800 meters, the process further includes curvature direction identification and three-dimensional pre-bias correction, specifically including:

[0018] The curve type is determined based on the bridge design data: when the bridge deck elevation is higher than the theoretical tangent, it is a convex curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical upward direction; otherwise, it is a concave curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical downward direction.

[0019] Pre-offset grade control: The plane pre-offset distance is taken from the table of curvature radius and compensation distance; the vertical pre-offset distance is taken as 15%~25% of the plane pre-offset distance, with positive values ​​for convex curves and negative values ​​for concave curves;

[0020] The pre-offset distance is decomposed into a horizontal vector and a vertical vector. The horizontal vector is directed from the center of the planar curve to the theoretical center point of the column. The vertical vector is directed vertically upward when it is a convex curve and vertically downward when it is a concave curve.

[0021] Lofting guidance: By calling up BIM model data through a total station, the curve type is identified, and the three-dimensional pre-offset direction indicator and pre-offset value are dynamically displayed on the lofting interface.

[0022] Preferably, the specific method for adjusting the column posture in step two to achieve a bidirectional deviation of ≤1mm is as follows:

[0023] At the gap between the anchor flange and the base at the bottom of the column, four sets of wedge-shaped fine-tuning pads are symmetrically installed along the longitudinal and transverse directions of the bridge. The pads are made of alloy material with four progressively increasing thicknesses of 0.2mm, 0.5mm, 1mm, and 2mm.

[0024] Based on the deviation direction and value fed back by the laser target, calculate the required thickness of the pad block combination. If the deviation is adjusted in the longitudinal direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. If the deviation is adjusted in the transverse direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. After each set of pad block adjustments is completed, the pre-embedded bolts are pre-tightened to 10% of the design torque with a torque wrench for temporary fixation.

[0025] During the adjustment process, a 3D laser scanner is used for continuous monitoring. When the deviation value is ≤1mm, the fine-tuning shim that exceeds the thickness is removed, and then it is fixed by spot welding at the flange edge.

[0026] Preferably, dynamic correction of the bridge deck shape is added before step one, specifically as follows:

[0027] A 3D laser scanner was used to scan the bridge deck with a 1m×1m grid density to generate an actual elevation point cloud map.

[0028] Compare with the design elevation data and calculate the local correction amount: when the actual elevation of the grid point deviates from the design value by more than 3mm, it is marked as a correction zone, and the correction amount ΔZ = actual elevation - design elevation;

[0029] When laying out, the total station loads the correction grid data, and the coordinates of the theoretical center point of the column are adjusted according to the formula: Z correction = Z design + k × ΔZ, where k is the compensation coefficient;

[0030] Perform a pre-compensation operation at the corrected coordinate points.

[0031] Preferably, the compensation coefficient k is set in stages according to the magnitude of the correction: when |ΔZ| ≤ 5mm, k = 0.6; when 5mm < |ΔZ| ≤ 10mm, k = 0.5; when |ΔZ| > 10mm, k = 0.4.

[0032] Preferably, the dynamic correction of the bridge deck is performed before the three-dimensional pre-bias correction. The vertical vector calculation of the three-dimensional pre-bias correction is based on the coordinates of the center point of the column after dynamic correction, and the final total vertical offset does not exceed ±15mm of the design elevation.

[0033] The present invention has at least the following beneficial effects:

[0034] First, this invention ensures the installation accuracy of the corrugated beam steel guardrail during construction, guaranteeing a firm connection between components and adapting to the structural characteristics of the bridge, thereby ensuring the guardrail's performance and safety. The three-stage symmetrical tightening of the embedded bolts followed by static verification effectively prevents bolt deformation or loosening due to excessive instantaneous force, ensuring the firmness of the connection between the posts and the base and reducing subsequent maintenance work caused by loose bolts. The temporary tightening of the brackets provides a stable support foundation for the subsequent installation of the corrugated beam. Tightening the bolts twice in a specific sequence ensures even stress distribution across the corrugated beam, preventing beam deformation due to excessive localized stress and ensuring the stability and integrity of the overall structure of the spliced ​​corrugated beam. The set static time allows the bolts sufficient time to adapt to the stress, reducing the possibility of later torque attenuation and ensuring the corrugated beam maintains a good structural condition after installation.

[0035] Secondly, the clearly defined correspondence in this invention allows construction personnel to quickly and accurately obtain the pre-offset distance, avoiding improper pre-offset due to misjudgment, ensuring the accuracy of guardrail construction on curved bridge spans, enabling the guardrail to better adapt to the curved structure of the bridge, and enhancing the overall stability of the guardrail; it also provides a scientific and accurate calculation method for the pre-offset distance of the intermediate radius of curvature, ensuring that all curved bridge spans can receive appropriate pre-offset treatment, avoiding construction deviations caused by a lack of corresponding data, and further improving the precision and applicability of guardrail construction.

[0036] Third, the accurate curve type determination of this invention is a prerequisite for reasonable pre-deflection, ensuring that the pre-deflection direction conforms to the actual curve structure of the bridge, allowing the guardrail to better fit the bridge in three-dimensional space, improving the overall coordination and safety of the guardrail; graded control of the pre-deflection amount can be adjusted according to the different characteristics of the curve, and the reasonable combination of planar and vertical pre-deflection makes the positioning of the guardrail on the curved bridge span more accurate, better resisting the lateral and vertical forces generated by vehicles traveling on curves, and enhancing the load-bearing capacity of the guardrail; vector decomposition can clearly divide the pre-deflection distance in the horizontal and vertical directions, allowing construction personnel to more clearly understand the direction and magnitude of the pre-deflection, facilitating accurate operation in actual construction, ensuring the accuracy of the pre-deflection, and ensuring that the position of each component of the guardrail in three-dimensional space is accurate.

[0037] Fourth, this invention, through symmetrical superposition and reduction, can precisely control the posture of the posts, ensuring a bidirectional deviation of ≤1mm, resulting in extremely high installation accuracy. Continuous monitoring and temporary fixing during the adjustment process guarantee the accuracy and stability of the adjustment, while the final spot welding fixation further ensures the positional stability of the posts during long-term use, providing a solid foundation for the overall performance of the guardrail.

[0038] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0040] According to one embodiment of the present invention, a method for constructing a corrugated beam steel guardrail includes the following steps:

[0041] Step 1: Bridge Deck Benchmark Laying Out and Pre-compensation: Using the bridge design benchmark as the reference, use a total station to mark the theoretical column center points on the bridge deck crash barrier or guardrail base according to the design spacing (the design spacing can be 1 meter, 1.5 meters, 2 meters, etc.). For curved bridge spans with a curvature radius ≤ 800 meters, determine the pre-offset distance pointing to the center of the curve according to the curvature radius and compensation distance comparison table, and mark the pre-offset column installation points at the laying out points (marking tools, such as markers, spray paint, etc., are used to mark the pre-offset column installation points).

[0042] Step 2, 3D Laser Reference Anchoring Fine Adjustment: At the column installation point, initially align the anchoring flange at the bottom of the column with the pre-embedded bolts in the base; set up a 3D laser scanner to establish a unified digital reference plane including the longitudinal and transverse slopes of the bridge deck; fix a laser target on the side of the column to provide real-time feedback on the deviation values ​​between the column and the design position in the longitudinal and transverse directions; when the deviation value in the longitudinal or transverse direction is >2mm, adjust the column posture until the bidirectional deviation is ≤1mm; tighten the pre-embedded bolts symmetrically in three levels according to the design torque values ​​of 30%, 60%, and 100%; after each level of tightening, let it stand for 1 minute and check the deviation value; after the column is fixed, install the bracket at the design elevation position, and temporarily tighten the bracket connecting bolts with 60% of the design torque;

[0043] Step 3, Corrugated beam splicing: Splice the corrugated beam on the ground. When splicing, use a digital torque wrench to tighten the splicing bolts in two stages. First, pre-tighten to 40% of the design torque value. After standing for 5 minutes, tighten to 100% of the design torque in a symmetrical alternating sequence from the middle of the span to both ends.

[0044] Step 4, Guardrail Installation: Hoist the assembled corrugated beam to the bracket support position, ensuring the bottom of the beam falls into the bracket. Use a hydraulic jack to apply a lateral adjustment force of ≤5kN to the corrugated beam to adjust its alignment. Tighten the bracket connecting bolts to 100% of the design torque. The corrugated beam steel guardrail construction is complete. Before applying force with the hydraulic jack, install a temporary anti-push support between the corrugated beam and the adjacent fixed guardrail section. This support consists of a double-acting screw and end clamps. The clamps are held in the middle of the corrugated beam web height direction. When applying force, simultaneously tighten the double-acting screw to provide a reverse balancing force. The hydraulic jack's point of action is directly above the bracket. (The length of the double-acting screw of the temporary anti-push support can be 30cm, 40cm, 50cm, etc., and the clamping width of the end clamps can be selected according to the thickness of the corrugated beam web, such as 5cm, 8cm, 10cm, etc. The temporary anti-push support, consisting of a double-acting screw and end clamps, is used to provide a reverse balancing force.) The hoisting equipment is used to lift the assembled corrugated beams to the support brackets. This technical solution ensures the installation accuracy of the corrugated beam steel guardrail during construction, ensuring a firm connection between components, adapting to the structural characteristics of the bridge, and thus guaranteeing the guardrail's performance and safety. The three-stage symmetrical tightening of the embedded bolts followed by static verification effectively avoids deformation or loosening of the bolts due to excessive instantaneous force, ensuring the firmness of the connection between the column and the base, and reducing maintenance work caused by loose bolts later. The temporary fastening of the brackets provides a stable support foundation for the subsequent installation of the corrugated beams. Tightening the bolts twice in a specific sequence ensures even stress distribution across the corrugated beam, preventing beam deformation due to excessive localized stress, and ensuring the stability and integrity of the overall structure of the assembled corrugated beam. The set static time allows the bolts sufficient time to adapt to the stress, reducing the possibility of torque attenuation later, and ensuring the corrugated beam maintains a good structural condition after installation.

[0045] According to another embodiment of the present invention, a table of curvature radius and compensation distance is provided, in which the pre-offset distance value increases in a decreasing gradient according to the curvature radius, and the specific correspondence is as follows:

[0046] A curvature radius of 800m corresponds to a pre-offset distance of 10mm, a curvature radius of 500m corresponds to a pre-offset distance of 18mm, a curvature radius of 300m corresponds to a pre-offset distance of 25mm, and a curvature radius ≤200m corresponds to a pre-offset distance of 35mm (based on the curvature radius of the curved bridge span, the corresponding pre-offset distance can be directly looked up from the curvature radius and compensation distance comparison table. For example, when the curvature radius is 800m, the pre-offset distance is 10mm).

[0047] For intermediate curvature radius values ​​not listed, the pre-offset distance is calculated using linear interpolation.

[0048] d=d1+(R-R1)(d2-d1) / (R2-R1)

[0049] Where R is the actual radius of curvature, R2 and R1 are adjacent radius values ​​in the lookup table with R1 < R < R2, d1 is the pre-offset distance corresponding to R1, and d2 is the pre-offset distance corresponding to R2. Using this technical solution, the clear correspondence of this invention allows construction personnel to quickly and accurately obtain the pre-offset distance, avoiding improper pre-offset due to misjudgment, ensuring the accuracy of guardrail construction on curved bridge spans, enabling the guardrail to better adapt to the curved structure of the bridge, and enhancing the overall stability of the guardrail; it also provides a scientific and accurate calculation method for the pre-offset distance of the intermediate radius of curvature, ensuring that all curved bridge spans receive appropriate pre-offset treatment, avoiding construction deviations due to a lack of corresponding data, and further improving the accuracy and applicability of guardrail construction.

[0050] According to another embodiment of the present invention, in step four, after the bottom of the corrugated beam is lowered into the bracket, a rubber elastic gasket is inserted into the gap between the web of the corrugated beam and the side wall of the bracket. The hardness of the rubber elastic gasket is 70±5 Shore A, and the compression set (70℃×24h) is ≤25%; the gasket thickness is 1.2-1.5 times the gap width (EPDM rubber elastic gasket), and it is pre-compressed to 90% of the design gap and held for 10 minutes before installation. By adopting this technical solution, the present invention can effectively fill the gap by setting a rubber elastic pad, avoiding hard contact between the corrugated beam and the bracket. When the vehicle vibrates or is impacted, it can play a good buffering role, reducing wear and damage between the two. It can absorb the instantaneous vibration energy caused by vehicle impact or wind load, avoid local stress concentration caused by rigid metal contact, and extend the service life of the connection between the bracket and the corrugated beam. The compression adaptability of the rubber pad allows for a lateral alignment deviation of ±1.5mm when the corrugated beam is hoisted. The gap is naturally filled by elastic deformation, simplifying the linear adjustment operation of the hydraulic jack.

[0051] According to another embodiment of the present invention, in step four, the connecting bolts of the bracket are tightened to 100% of the design torque. The bolts are then passed sequentially through the bracket, the rubber elastic gasket, and the corrugated beam web for secure tightening. During tightening, a digital torque wrench is used to tighten the bolts symmetrically in three stages at 30%, 60%, and 100% of the design torque, with a 2-minute interval between each tightening. This technical solution, by tightening the bolts symmetrically in three stages with a certain time interval, allows the bolt force to increase gradually and evenly, avoiding excessive local stress caused by a single tightening. This ensures a tight and secure connection between the bolts and each component, reducing the possibility of bolt loosening. Simultaneously, it protects the rubber elastic gasket from excessive compression and damage, ensuring its proper cushioning performance and further improving the overall stability of the guardrail.

[0052] According to another embodiment of the present invention, after step four (the inspection step after construction is completed), a horizontal reciprocating load simulating wind vibration or bridge deck vibration is applied to the installed guardrail section. The amplitude of the simulated wind vibration or bridge deck vibration is ±2mm, the frequency is 0.5-1Hz, and the duration is 120 seconds (a vibration loading device can be used, according to another embodiment of the present invention). During the load application process, the change in bolt torque at the connection between the bracket and the column is monitored in real time. If the torque attenuation at any monitoring point is >5% of the design torque value, the bolt at that point needs to be retightened to 100% of the design torque. By adopting this technical solution, the simulated load of the present invention can simulate the vibration environment that the guardrail may encounter in actual use, check the connection strength and stability of each component of the guardrail in advance, discover potential loosening problems in time, provide a basis for subsequent reinforcement treatment, and ensure that the guardrail can withstand various vibration loads in actual use.

[0053] According to another embodiment of the present invention, in step one, the curvature direction identification and three-dimensional pre-bias correction are further included for curved bridge spans with a curvature radius ≤ 800 meters, specifically including:

[0054] The curve type is determined based on the bridge design data: when the bridge deck elevation (one way to achieve this is by using a level to measure the bridge deck elevation and the theoretical tangent elevation) is higher than the theoretical tangent, it is a convex curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical upward direction; otherwise, it is a concave curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical downward direction.

[0055] Pre-offset grade control: The plane pre-offset distance is taken from the table of curvature radius and compensation distance; the vertical pre-offset distance is taken as 15% to 25% of the plane pre-offset distance, with positive values ​​(upward) for convex curves and negative values ​​(downward) for concave curves.

[0056] The pre-offset distance is decomposed into a horizontal vector and a vertical vector. The horizontal vector is directed from the center of the planar curve to the theoretical center point of the column. The vertical vector is directed vertically upward when it is a convex curve and vertically downward when it is a concave curve.

[0057] Layout guidance: By calling BIM model data using a total station (the BIM model data should at least include the bridge's horizontal alignment, vertical curve parameters, and the design 3D coordinates of the center points of each column), the curve type is identified, and the 3D pre-offset direction indicator and pre-offset value are dynamically displayed on the layout interface. Using this technical solution, accurate curve type determination is a prerequisite for reasonable pre-offset, ensuring that the pre-offset direction conforms to the actual curve structure of the bridge, allowing the guardrail to better fit the bridge in 3D space, improving the overall coordination and safety of the guardrail; graded control of the pre-offset amount allows for targeted adjustments based on different curve characteristics, and the reasonable combination of horizontal and vertical pre-offsets makes the guardrail's positioning on the curved bridge span more precise, better resisting the lateral and vertical forces generated by vehicles traveling on curves, enhancing the guardrail's load-bearing capacity; vector decomposition clearly divides the pre-offset distance in the horizontal and vertical directions, allowing construction personnel to more clearly understand the direction and magnitude of the pre-offset, facilitating accurate operation in actual construction, ensuring the accuracy of the pre-offset, and ensuring the accurate position of each guardrail component in 3D space.

[0058] According to another embodiment of the present invention, the specific method for adjusting the column posture to a bidirectional deviation of ≤1mm in step two is as follows:

[0059] At the gap between the anchor flange and the base at the bottom of the column, four sets of wedge-shaped fine-tuning pads are symmetrically installed along the longitudinal and transverse directions of the bridge. The pads are made of alloy material with four progressively increasing thicknesses of 0.2mm, 0.5mm, 1mm, and 2mm.

[0060] Based on the deviation direction and value fed back by the laser target, calculate the required thickness of the pad block combination. If the deviation is adjusted in the longitudinal direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. If the deviation is adjusted in the transverse direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. After each set of pad block adjustments is completed, the pre-embedded bolts are pre-tightened to 10% of the design torque with a torque wrench for temporary fixation.

[0061] During the adjustment process, a 3D laser scanner is used for continuous monitoring. When the deviation is ≤1mm, the excess adjustment shims are removed, and then spot-welded to the flange edge for fixation, followed by tightening the bolts. The wedge-shaped adjustment shims can be made of alloy material and are installed symmetrically along the longitudinal and transverse directions of the bridge at the gap between the anchor flange and the base at the bottom of the column. Using this technical solution, the present invention can precisely control the posture of the column through symmetrical superposition and reduction, ensuring a bidirectional deviation of ≤1mm, resulting in extremely high installation accuracy. Continuous monitoring and temporary fixing during the adjustment process ensure the accuracy and stability of the adjustment, while the final spot welding further ensures the positional stability of the column during long-term use, providing a solid foundation for the overall performance of the guardrail.

[0062] According to another embodiment of the present invention, a dynamic correction of the bridge deck shape is added before step one, specifically as follows:

[0063] A 3D laser scanner (the mounting location is the area around the bridge deck to cover the entire bridge deck) is used to scan the bridge deck with a 1m×1m grid density to generate an actual elevation point cloud map.

[0064] Compare with the design elevation data and calculate the local correction amount: when the actual elevation of the grid point deviates from the design value by more than 3mm, it is marked as a correction zone, and the correction amount ΔZ = actual elevation - design elevation;

[0065] When laying out, the total station loads the correction grid data, and the coordinates of the theoretical center point of the column are adjusted according to the formula: Z correction = Z design + k × ΔZ, where k is the compensation coefficient;

[0066] A pre-compensation operation is performed at the corrected coordinate points; first, the bridge deck shape is dynamically corrected to obtain the corrected coordinates of the column center point; then, a three-dimensional pre-bias correction calculation is performed based on these coordinates. Using this technical solution, the present invention adjusts the column coordinates according to the correction amount, enabling the column installation position to better match the actual elevation of the bridge deck. This avoids column tilting or improper stress caused by local elevation deviations of the bridge deck, ensuring the overall flatness and stability of the guardrail, and allowing the guardrail to better perform its protective function.

[0067] According to another embodiment of the present invention, the compensation coefficient k is set in stages according to the magnitude of the correction: when |ΔZ| ≤ 5mm, k = 0.6; when 5mm < |ΔZ| ≤ 10mm, k = 0.5; when |ΔZ| > 10mm, k = 0.4. The value and grading principle of the compensation coefficient k are determined through finite element analysis and a large number of engineering tests. Its core objective is to ensure that after the combined effect of compensation and post-construction settlement of the bridge deck, the deviation between the final installation elevation of the column top and the design elevation can be controlled within the allowable range of ±5mm. Theoretical analysis and practice show that areas with larger bridge deck elevation deviations ΔZ often have relatively low base layer density or stiffness, and under the action of guardrail load and subsequent bridge deck paving, their potential for post-construction settlement is also greater. Therefore, for points with a large ΔZ, a smaller compensation coefficient k is needed to avoid overcompensation at present, which could lead to lower column elevations later due to bridge deck settlement. Conversely, for points with a small ΔZ, a larger compensation coefficient k can be used to achieve more sufficient real-time compensation. Based on this principle, the value of K in this invention is determined. Using this technical solution, the invention sets different compensation coefficients according to different degrees of bridge deck elevation deviation, making coordinate adjustments more reasonable and avoiding column installation deviations caused by overcompensation or undercompensation. For areas with small deviations, appropriately increasing the compensation coefficient can better match the actual situation; for areas with large deviations, decreasing the compensation coefficient can avoid over-adjustment affecting the overall structure, ensuring the accuracy and safety of column installation.

[0068] According to another embodiment of the present invention, dynamic bridge deck correction is performed before three-dimensional pre-bias correction. The vertical vector calculation for three-dimensional pre-bias correction is based on the coordinates of the column center point after dynamic correction, and the final total vertical offset does not exceed ±15mm of the design elevation. Using this technical solution, the execution sequence of the present invention ensures the orderly progress of the correction work. First, dynamic bridge deck correction is performed to ensure that the column coordinates are based on the actual bridge deck conditions. Then, three-dimensional pre-bias correction is performed, making the pre-bias more consistent with the curved structure of the bridge, avoiding mutual interference between the two corrections, improving the overall effect and accuracy of the correction, and ensuring the quality of guardrail construction. The limitation on the total vertical offset ensures that the vertical position of the guardrail is within a reasonable range, avoiding excessive offset that could lead to incompatibility between the guardrail and the bridge deck or other structures, affecting vehicle driving safety. It also ensures that the stress on the guardrail meets design requirements, avoiding additional stress due to excessive offset, and ensuring the structural stability and service life of the guardrail.

[0069] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A construction method for corrugated beam steel guardrails, characterized in that, Includes the following steps: Step 1: Bridge deck benchmark layout and pre-compensation: Using the bridge design benchmark as the benchmark, use a total station to mark the theoretical column center point on the bridge deck crash barrier or guardrail base according to the design spacing. For curved bridge spans with a curvature radius ≤ 800 meters, determine the pre-offset distance pointing to the center of the curve according to the curvature radius and compensation distance comparison table, and mark the pre-offset column installation point at the layout point. Step 2, 3D Laser Reference Anchoring Fine Adjustment: At the column installation point, initially align the anchoring flange at the bottom of the column with the pre-embedded bolts in the base; set up a 3D laser scanner to establish a unified digital reference plane including the longitudinal and transverse slopes of the bridge deck; fix a laser target on the side of the column to provide real-time feedback on the deviation values ​​between the column and the design position in the longitudinal and transverse directions; when the deviation value in the longitudinal or transverse direction is >2mm, adjust the column posture until the bidirectional deviation is ≤1mm; tighten the pre-embedded bolts symmetrically in three levels according to the design torque values ​​of 30%, 60%, and 100%; after each level of tightening, let it stand for 1 minute and check the deviation value; after the column is fixed, install the bracket at the design elevation position, and temporarily tighten the bracket connecting bolts with 60% of the design torque; Step 3, Corrugated beam splicing: Splice the corrugated beam on the ground. When splicing, use a digital torque wrench to tighten the splicing bolts in two stages. First, pre-tighten to 40% of the design torque value. After standing for 5 minutes, tighten to 100% of the design torque in a symmetrical alternating sequence from the middle of the span to both ends. Step 4, Guardrail Installation: Hoist the assembled corrugated beam to the bracket support position, so that the bottom of the corrugated beam falls into the bracket. Use a hydraulic jack to apply a lateral adjustment force of ≤5kN to the corrugated beam to adjust the beam's alignment. Tighten the connecting bolts of the bracket to 100% of the design torque. The corrugated beam steel guardrail construction is now complete. A table showing the relationship between radius of curvature and compensation distance shows that the pre-offset distance increases in a decreasing gradient according to the radius of curvature. The specific correspondence is as follows: A curvature radius of 800m corresponds to a pre-offset distance of 10mm, a curvature radius of 500m corresponds to a pre-offset distance of 18mm, a curvature radius of 300m corresponds to a pre-offset distance of 25mm, and a curvature radius ≤200m corresponds to a pre-offset distance of 35mm. For intermediate curvature radius values ​​not listed, the pre-offset distance is calculated using linear interpolation. d=d1+(R-R1)(d2-d1) / (R2-R1) Where R is the actual radius of curvature, R2 and R1 are adjacent radius values ​​in the reference table and R1 < R < R2, d1 is the pre-offset distance corresponding to R1, and d2 is the pre-offset distance corresponding to R2.

2. The construction method for corrugated beam steel guardrail as described in claim 1, characterized in that, In step four, after the bottom of the corrugated beam falls into the bracket, a rubber elastic pad is inserted into the gap between the web of the corrugated beam and the side wall of the bracket.

3. The construction method for corrugated beam steel guardrail as described in claim 2, characterized in that, In step four, tighten the connecting bolts of the bracket to 100% of the design torque. Use the bolts to pass through the bracket, rubber elastic pad, and corrugated beam web in sequence for fastening. When tightening, use a digital torque wrench to tighten symmetrically in three stages at 30%, 60%, and 100% of the design torque value, with a 2-minute interval between each tightening.

4. The construction method for corrugated beam steel guardrail as described in claim 1, characterized in that, After step four, apply a horizontal reciprocating load simulating wind vibration or bridge deck vibration to the installed guardrail section. The amplitude of the simulated wind vibration or bridge deck vibration is ±2mm, the frequency is 0.5-1Hz, and the duration is 120 seconds. During the load application process, monitor the change in bolt torque at the connection between the bracket and the column in real time. If the torque attenuation at any monitoring point is greater than 5% of the design torque value, the bolt at that point needs to be retightened to 100% of the design torque.

5. The construction method for corrugated beam steel guardrail as described in claim 1, characterized in that, In step one, for curved bridge spans with a curvature radius ≤ 800 meters, the process also includes curvature direction identification and three-dimensional pre-bias correction, specifically including: The curve type is determined based on the bridge design data: when the bridge deck elevation is higher than the theoretical tangent, it is a convex curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical upward direction; otherwise, it is a concave curve, and the pre-deflection direction is the combined direction of the plane pointing to the center of the circle and the vertical downward direction. Pre-offset grade control: The plane pre-offset distance is taken from the table of curvature radius and compensation distance; the vertical pre-offset distance is taken as 15%~25% of the plane pre-offset distance, with positive values ​​for convex curves and negative values ​​for concave curves; The pre-offset distance is decomposed into a horizontal vector and a vertical vector. The horizontal vector is directed from the center of the planar curve to the theoretical center point of the column. The vertical vector is directed vertically upward when it is a convex curve and vertically downward when it is a concave curve. Lofting guidance: By calling up BIM model data through a total station, the curve type is identified, and the three-dimensional pre-offset direction indicator and pre-offset value are dynamically displayed on the lofting interface.

6. The construction method for corrugated beam steel guardrail as described in claim 1, characterized in that, The specific method for adjusting the column posture in step two to ensure a bidirectional deviation of ≤1mm is as follows: At the gap between the anchor flange and the base at the bottom of the column, four sets of wedge-shaped fine-tuning pads are symmetrically installed along the longitudinal and transverse directions of the bridge. The pads are made of alloy material with four progressively increasing thicknesses of 0.2mm, 0.5mm, 1mm, and 2mm. Based on the deviation direction and value fed back by the laser target, calculate the required thickness of the pad block combination. If the deviation is adjusted in the longitudinal direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. If the deviation is adjusted in the transverse direction of the bridge, pad blocks are alternately stacked on the corresponding side, with each stack not exceeding 1mm in thickness, and the thickness is reduced by the same amount on the opposite side. After each set of pad block adjustments is completed, the pre-embedded bolts are pre-tightened to 10% of the design torque with a torque wrench for temporary fixation. During the adjustment process, a 3D laser scanner is used for continuous monitoring. When the deviation value is ≤1mm, the fine-tuning shim that exceeds the thickness is removed, and then it is fixed by spot welding at the flange edge.

7. The construction method for corrugated beam steel guardrail as described in claim 1, characterized in that, Before step one, dynamic correction of the bridge deck shape is added, specifically as follows: A 3D laser scanner was used to scan the bridge deck with a 1m×1m grid density to generate an actual elevation point cloud map. Compare with the design elevation data and calculate the local correction amount: when the actual elevation of the grid point deviates from the design value by more than 3 mm, it is marked as a correction zone, and the correction amount ΔZ = actual elevation - design elevation; When laying out, the total station loads the correction grid data, and the coordinates of the theoretical center point of the column are adjusted according to the formula: Z correction = Z design + k × ΔZ, where k is the compensation coefficient; Perform a pre-compensation operation at the corrected coordinate points.

8. The construction method for corrugated beam steel guardrail as described in claim 7, characterized in that, The compensation coefficient k is set in stages according to the magnitude of the correction: when |ΔZ| ≤ 5mm, k = 0.6; when 5mm < |ΔZ| ≤ 10mm, k = 0.5; when |ΔZ| > 10mm, k = 0.

4.

9. The construction method for corrugated beam steel guardrail as described in claim 7, characterized in that, Dynamic correction of the bridge deck takes precedence over three-dimensional pre-bias correction. The vertical vector calculation for three-dimensional pre-bias correction is based on the coordinates of the center point of the column after dynamic correction, and the final total vertical offset does not exceed ±15mm of the design elevation.