Elastic concrete flexible splicing construction method for new and old bridges

Abstract

The invention provides a new and old bridge elastic concrete flexible splicing construction method, and belongs to the technical field of bridge construction.The new and old bridge elastic concrete flexible splicing construction method includes the steps that firstly, the deviation value of a geometric center line and a representative center line is determined through measurement, and a construction sideline is determined according to the deviation value; then grooving and cleaning are conducted along the construction side line, and the flatness value is measured after fine aggregate concrete is used for leveling treatment; then brushing an epoxy adhesive, pasting a rubber water-stop belt, and laying an anti-seismic rubber cushion block to form constraint damping with the steel plate; covering with a galvanized steel sheet, wherein the center line coincides with the weighted center line; then pouring GD elastic concrete, calculating the compensation height of the pouring height according to the flatness value, and compacting by using a small road roller; then carrying out hot joint treatment and surface trowelling to ensure that the width of the joint is neat, and measuring and recording the linear deviation of the joint; and finally, after the concrete is cooled, final adjustment is performed according to linear deviation, and the problem of sudden change of pavement height difference caused by structural settlement difference is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge construction. Specifically, it relates to a construction method for flexible splicing of elastic concrete between new and old bridges. Background Art

[0002] Bridge splicing technology is widely used in road engineering. Especially during the connection of new and old bridges, to ensure driving safety and comfort, smooth transition is a key technical index. Traditional bridge splicing technologies mainly adopt rigid connection methods, such as steel plate caulking, concrete lapping, etc. These methods usually construct according to the theoretical splicing position on the design drawings during the construction process, lacking an adaptive adjustment mechanism for the actual settlement state.

[0003] However, in actual engineering applications, due to differences in construction time, foundation treatment methods, and material aging degrees between new and old bridges, they often exhibit different settlement characteristics. Traditional rigid connection technologies cannot effectively adapt to this settlement difference, resulting in obvious height difference mutations at the splicing joints. This height difference mutation not only causes a bumpy feeling when the vehicle passes, reducing driving comfort, but also accelerates the wear of road surface materials due to increased impact loads, and even triggers traffic safety accidents in extreme cases.

[0004] Facing the problem of height difference mutation of the road surface caused by structural settlement differences at the splicing joints of new and old bridges, the existing technologies are difficult to provide effective solutions. Especially after years of operation, the settlement difference between new and old bridges will further expand. The traditional rigid connection method lacks the ability to adapt to this dynamic change, making the splicing joint one of the most vulnerable links in the road system, seriously affecting the overall service performance of the bridge and driving safety. That is to say, there is a technical problem of height difference mutation of the road surface caused by structural settlement differences at the splicing joints of new and old bridges in the existing technologies. Summary of the Invention

[0005] In view of this, the present invention provides a construction method for flexible splicing of elastic concrete between new and old bridges, which can solve the technical problem of height difference mutation of the road surface caused by structural settlement differences at the splicing joints of new and old bridges in the existing technologies.

[0006] The present invention is implemented as follows: The present invention provides a construction method for elastic concrete flexible splicing of new and old bridges, which includes: measuring and setting out according to the center position of the joint, accurately releasing the geometric center line and the representative center line of the joint, measuring the deviation value between the geometric center line and the representative center line, and releasing the construction side lines to both sides of the geometric center line according to the deviation value; cutting grooves along the construction side lines and cleaning; leveling the bottom surface of the groove and measuring the flatness value; drying after cleaning the groove, applying epoxy adhesive and pasting a rubber waterstop; setting constraint damping at the joint, placing seismic rubber pads and steel plates; using galvanized steel plates to cover the joint in the middle, and the center line of the galvanized steel plate coincides with the weighted center line of the geometric center line and the representative center line and is fixed; pouring GD elastic concrete into the groove and compacting; performing thermal joint and surface treatment on the GD elastic concrete, measuring and recording the deviation of the joint line shape; after the GD elastic concrete cools naturally, making final adjustments according to the deviation of the joint line shape; the deviation value is used to correct the construction position to adapt to the actual deformation situation.

[0007] Among them, in the step of measuring and setting out according to the center position of the joint, accurately releasing the geometric center line and the representative center line of the joint, measuring the deviation value between the geometric center line and the representative center line, and releasing the construction side lines to both sides of the geometric center line according to the deviation value, construction side lines of 225 mm are released to both sides of the geometric center line according to the deviation value.

[0008] Among them, the step of setting constraint damping at the joint and placing seismic rubber pads and steel plates includes: setting constraint damping at the joint, covering the joint with seismic rubber pads of 200 mm × 500 mm × 20 mm, placing a steel plate of 200 mm × 250 mm × 20 mm on the upper layer, and the placement position of the seismic rubber pads is compensated and adjusted based on the deviation value.

[0009] Among them, the step of using galvanized steel plates to cover the joint in the middle, and the center line of the galvanized steel plate coincides with the weighted center line of the geometric center line and the representative center line and is fixed includes: using 4 galvanized steel plates of 200 mm × 500 mm × 6 mm to cover the joint in the middle, the center line of the galvanized steel plate coincides with the weighted center line of the geometric center line and the representative center line, and is fixed by perforating and connecting with M30 bolts.

[0010] Among them, the geometric center line refers to the theoretical splicing position center line measured and determined according to the bridge structure design drawings, and is directly measured by measuring instruments.

[0011] Among them, the representative center line refers to the actual splicing position center line after considering actual construction errors and bridge settlement, and is obtained by multi-point sampling measurement.

[0012] Among them, the weighted center line refers to the optimal splicing line determined by weighted calculation based on the geometric center line and the representative center line, considering the bridge stiffness and expected deformation, and is used to guide the installation position of the final galvanized steel plate.

[0013] Among them, the step of pouring and compacting the GD elastic concrete into the groove includes: pasting anti-fouling tapes on both sides outside the trench, pouring the prepared GD elastic concrete into the groove, and the pouring height is slightly higher than the top surface of the groove according to the compensation height calculated from the flatness value, and then compacting it with a small roller.

[0014] Among them, the steps of performing thermal joint and surface treatment on the GD elastic concrete and measuring and recording the linear deviation of the joint include: performing thermal joint treatment on the side of the GD elastic concrete, smoothing the surface, ensuring that the joint width is neat, the surface is flat, the height difference between the joint and the paving surface is less than ±2 mm, and measuring and recording the linear deviation of the joint.

[0015] Among them, the step of finally adjusting according to the linear deviation of the joint after the GD elastic concrete cools naturally includes: allowing the GD elastic concrete to cool naturally for no less than 2 hours in a fully enclosed state, and then performing the final adjustment according to the linear deviation of the joint.

[0016] The present invention proposes a construction method for flexible splicing of elastic concrete between new and old bridges. By accurately measuring the deviation value between the geometric center line and the representative center line, and combining the application of the constrained damping system and elastic materials, a dynamic adjustment mechanism based on the actual settlement state is established, realizing a smooth transition at the splicing location.

[0017] This method uses GD elastic concrete as the splicing material, and cooperates with the constrained damping system composed of seismic rubber pads and galvanized steel plates, successfully solving the problem of sudden height difference in traditional rigid connections. Elastic concrete has excellent deformation adaptability and can naturally transition the height difference between new and old bridges; while the constrained damping system provides buffering and support in the vertical direction, effectively controlling the sudden height difference caused by uneven settlement, so that when vehicles pass, they feel a smooth transition rather than a sudden impact.

[0018] The present invention successfully solves the problem of sudden height difference of the road surface caused by structural settlement difference at the splicing location between new and old bridges by introducing dynamic adjustment based on measured parameters and the application of flexible materials. The accurate measurement and corresponding adjustment of the deviation value, flatness value and linear deviation of the joint during the construction process ensure the flatness of the splicing location under static conditions and the dynamic adaptability to settlement difference during long-term service, significantly improving the service performance of the bridge and the driving comfort. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a flow chart of a construction method for elastic concrete flexible splicing of new and old bridges;

[0021] Figure 2 It is a schematic structural diagram of the construction of constrained damping;

[0022] Figure 3 It is a schematic diagram of center line measurement and positioning;

[0023] In the attached drawings, the list of components represented by each label is as follows:

[0024] 10. Constrained damping; 11. Galvanized steel plate; 12. Seismic rubber pad; 13. Steel plate; 14. M30 bolt. Specific implementation manners

[0025] 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 in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] As Figures 1-3 shown, the method includes the following steps:

[0027] S01. Perform measurement and lofting according to the center position of the joint, accurately lay out the geometric center line and the representative center line of the joint, measure the deviation value between the geometric center line and the representative center line, and lay out the construction side lines 225 mm on both sides of the geometric center line according to the deviation value;

[0028] S02. Cut a groove along the construction side line with a cutting machine, control the cutting depth at 130 mm, and chisel and clean up all the asphalt concrete pavement layers within the cutting range;

[0029] S03. Level the bottom surface of the groove with fine aggregate concrete to ensure that the heights of the leveling layers on both sides of the joint are on the same plane, control the depth at about 130 mm, and measure the flatness value of the leveling layer;

[0030] S04. After cleaning the groove with an air compressor gun, dry it with a flame gun, apply epoxy binder and paste a rubber water stop, wherein the coating thickness of the epoxy binder is dynamically adjusted according to the flatness value;

[0031] S05. Set the constrained damping 10 at the joint, cover the joint with a seismic rubber pad 12 of 200 mm × 500 mm × 20 mm, and place a steel plate 13 of 200 mm × 250 mm × 20 mm on the upper layer. The placement position of the seismic rubber pad 12 is compensated and adjusted based on the deviation value;

[0032] S06. Use four galvanized steel plates 11 with dimensions of 200 mm × 500 mm × 6 mm to cover the joints in the center. The center line of the galvanized steel plates 11 coincides with the geometric center line and the weighted center line of the representative center line, and is fixed by perforating and connecting with M30 bolts 14.

[0033] S07. Paste anti - pollution tapes on both sides outside the trench, pour the prepared GD elastic concrete into the trench. The pouring height is slightly higher than the top surface of the trench according to the compensation height calculated from the flatness value, and compact it with a small roller.

[0034] S08. Conduct thermal joint treatment on the side of the GD elastic concrete, and smooth the surface to ensure that the joint width is neat, the surface is flat, the height difference between the joint and the paving surface is less than ±2 mm, and measure and record the linear deviation of the joint.

[0035] S09. After allowing the GD elastic concrete to cool naturally for at least 2 hours in a fully enclosed state, make final adjustments according to the linear deviation of the joint before it can be delivered for use.

[0036] Among them, the geometric center line specifically refers to the center line of the theoretical splicing position measured and determined according to the bridge structure design drawings, which is directly measured by measuring instruments.

[0037] Among them, the representative center line specifically refers to the center line of the actual splicing position after considering the actual construction error and the bridge settlement, which is obtained by multi - point sampling measurement.

[0038] Among them, the deviation value specifically refers to the distance difference between the geometric center line and the representative center line, which is used to correct the construction position to adapt to the actual deformation situation.

[0039] Among them, GD elastic concrete specifically refers to a special concrete material with excellent elastic properties, which can meet the deflection requirements generated by the up - and - down vibration when the vehicle passes, so that the joint does not crack or bulge.

[0040] Among them, the flatness value specifically refers to the quantitative index of the height difference of the bottom surface of the trench, which is obtained by multi - point measurement with a laser level, and is used to guide the subsequent material consumption and construction process adjustment.

[0041] Among them, the linear deviation of the joint specifically refers to the deviation degree between the completed joint and the design straight line, which is measured by a precision measuring instrument and is used to evaluate the construction quality and guide the final adjustment.

[0042] Among them, the constraint damping 10 specifically refers to a structural system composed of galvanized steel plates 11 and seismic rubber pads 12, which is used to control the height difference problem between the new and old bridges and reduce the sudden change of height difference caused by uneven settlement.

[0043] Among them, the weighted center line specifically refers to the optimal splicing line determined by weighted calculation based on the geometric center line and the representative center line, considering the bridge stiffness and expected deformation, and is used to guide the installation position of the final galvanized steel plate 11.

[0044] Among them, the compensation height specifically refers to the additional pouring height calculated according to the flatness value to ensure that the compacted elastic concrete can fill all uneven areas and form an ideal surface.

[0045] The specific implementation manners of the above steps will be described in detail below.

[0046] The specific implementation manner of step S01 is to determine the construction boundary by using the double center measurement method. First, use a total station to set measurement control points every 5 meters along the longitudinal direction of the bridge to obtain the geometric center line of the theoretical joint position; then use the multi-point sampling method to collect the actual position data of at least 15 sample points at the junction of the existing bridge and the new bridge, and calculate the representative center line through the least squares fitting algorithm; then calculate the deviation value between the two center lines. If the deviation value exceeds the threshold of 15 mm, the measurement data needs to be rechecked; finally, based on the finally confirmed deviation value, use the geometric center line as the reference and release 225 mm of construction sidelines to both sides. The purpose of this step is to accurately determine the construction scope, ensure the accuracy of the subsequent grooving position, and prevent structural damage or insecure splicing caused by over-deep or under-deep cutting.

[0047] The specific implementation manner of step S02 is to use the layered cutting method to open the slot. First, use a diamond cutting machine to perform preliminary grooving along the construction sideline, and control the cutting depth within 70 mm; after the preliminary grooving is completed, perform the second cutting to control the total depth within 130 mm, and control the cutting accuracy error within ±5 mm; then use a hydraulic crusher to chisel the asphalt concrete pavement layer within the cutting range into blocks to avoid damaging the surrounding structure; finally, use a high-pressure air flow cleaning device to thoroughly clean the loose materials in the slot to ensure that there is no impurity residue. The purpose of this step is to create good basic conditions for the subsequent material construction, and the accurate control of the cutting depth is the key to ensuring that the main structure of the bridge is not damaged.

[0048] The specific implementation of step S03 is to use precise leveling technology to process the bottom of the groove. First, use an automatic level to measure the elevation every 1 meter along the bottom of the groove and record the height difference data; according to the measurement data, calculate the flatness value. If the flatness value exceeds 8 mm, local trimming is required; then lay a sand cushion layer with a thickness of 10 mm on the bottom of the groove to play a buffering role; then evenly spread fine aggregate concrete with a ratio of 1:2.5:3.5 on the sand cushion layer, and use a laser screed to monitor the surface height of the leveling layer in real time, controlling the height difference between the two sides of the leveling layer not to exceed 2 mm; the depth of the leveling layer is maintained at about 130 mm, and ensure that it forms a 90-degree right angle with the original paving layer. The flatness treatment of this step directly affects the splicing quality. By strictly controlling the levelness and depth of the leveling layer, a uniformly stressed base surface is provided for the subsequent materials.

[0049] The specific implementation of step S04 is to use a multi-level surface treatment process to improve the interface bonding performance. First, use an air compressor gun with a pressure not less than 0.8 MPa to thoroughly remove the dust and impurities in the groove; then use a flame gun with a temperature of 180 - 220 °C to uniformly heat and dry the inner surface of the groove, and the heating time is not less than 5 minutes until there is no obvious moisture on the surface; then, according to the flatness value measured in the previous step, calculate the coating thickness of the epoxy adhesive. For every 1 mm increase in the flatness value, the thickness of the epoxy adhesive increases by 0.2 mm correspondingly, and the reference thickness is 1.5 mm; then use a coating tool to evenly apply the epoxy adhesive to ensure that all inner surfaces of the groove are covered; finally, paste a rubber water stop strip with a width of 50 mm along the inner side wall of the groove, and the pasting height is not more than 20 mm from the top of the groove. This process effectively prevents moisture intrusion in the later stage and improves the overall waterproof performance of the splicing structure through surface treatment and the application of the interface adhesive.

[0050] The specific implementation of step S05 is to use a double-layer buffer structure design to achieve constrained damping installation. First, calculate the optimal placement position of the seismic rubber pads according to the deviation value. If the deviation value is positive, offset 50% of the deviation value towards the new bridge direction; if it is negative, offset 50% of the deviation value towards the old bridge direction; then place 200 mm × 500 mm × 20 mm seismic rubber pads with a Shore A hardness of 60 - 70 at the adjusted position, ensuring that the center of the pads is aligned with the weighted center line; then precisely place a 200 mm × 250 mm × 20 mm steel plate on the seismic rubber pads. The steel plate is made of Q345B and its surface is subjected to anti-corrosion treatment; at the same time, apply a layer of structural adhesive with a thickness of 0.5 mm on the contact surface between the rubber pads and the steel plate to enhance the connection stability between the two. The constrained damping system constructed in this step is based on the vibration reduction principle of material mechanics. The elastic deformation of the rubber pads absorbs vibration energy, and the steel plate provides stiffness constraints, jointly reducing the sudden change in height difference caused by settlement differences between the new and old bridges.

[0051] The specific implementation of step S06 is to install galvanized steel plates using the distributed fixing technology. First, calculate the geometric center line and the weighted center line representing the center line. The weighting coefficients are determined according to the stiffness ratio of the new and old bridge structures. When the stiffness ratio of the new bridge to the old bridge is 1:0.8, the weighting coefficients are 0.55 and 0.45 respectively. Then, arrange 4 hot-dip galvanized steel plates with dimensions of 200mm×500mm×6mm along the weighted center line, and the overlapping length of adjacent steel plates is 50mm. Next, install M30 high-strength bolts at the reserved hole positions of the steel plates, with no less than 4 fixing points for each steel plate. The tightening torque of the bolts is controlled between 120 and 140 N·m, and flat washers and spring washers are placed under the bolts. Finally, apply a structural sealant with a thickness of 1mm at the overlapping joints of adjacent steel plates to ensure the tightness of the joints. This step arranges galvanized steel plates through the scientifically calculated weighted center line and combines high-strength fixed connections to form a stable joint covering structure, providing a reliable bearing foundation for the upper elastic material.

[0052] The specific implementation of step S07 is to construct GD elastic concrete using the temperature-controlled pouring process. First, paste anti-pollution tapes with a width of 40mm on both sides outside the trench to prevent the elastic concrete from polluting the surrounding road surface. Then, mix GD elastic concrete at the concrete mixing plant according to the proportion requirements, with the mixing temperature controlled between 15 and 25°C and the mixing time not less than 90 seconds. Next, calculate the compensation height based on the flatness value, where the compensation height is equal to 1.2 times the flatness value plus the basic virtual arch height of 10mm. After transporting the mixed GD elastic concrete to the site, immediately pour it into the trench until the pouring height reaches the calculated compensation height. Subsequently, use a small roller with a weight of 1 to 2 tons to compact it at least 8 times to ensure that the surface flatness error does not exceed 3mm, and the compaction coefficient is not less than 0.98. The temperature-controlled pouring process adopted in this step ensures the fluidity and workability of GD elastic concrete, and the precise calculation of the compensation height guarantees the flatness after final compaction, which is the core link of the entire splicing process.

[0053] The specific implementation of step S08 is to improve the splicing quality using the fine surface treatment technology. First, after the GD elastic concrete begins to set, use a heater with a temperature of 130 to 150°C to perform thermal joint treatment on the edges, with a heating width of 30mm. Then, use a troweling tool to finely level the surface, and the leveling pressure is controlled between 0.05 and 0.1 MPa. Next, use a high-precision level to detect the joint width to ensure that the width error does not exceed 5mm. Measure the height difference between the joint and the paving surface using a straightedge and a level, and adjust it to less than ±2mm. Finally, use an electronic total station to measure along the joint every 2 meters and record the linear deviation data of the joint, with the linear deviation controlled within 10mm. The surface finishing technology adopted in this step ensures the flatness and linear aesthetics of the splicing joint, and the thermal joint treatment enhances the compactness and durability of the edge part, which is an important link in engineering quality control.

[0054] The specific implementation of step S09 is to complete the construction by combining natural curing and final adjustment. First, the completed splicing structure is naturally cooled under a fully enclosed condition for no less than 2 hours, and the ambient temperature should be between 10°C and 30°C. During the cooling period, the surface temperature of the GD elastic concrete is monitored, and the next operation can only be carried out when the surface temperature drops below 40°C. Then, according to the joint alignment deviation data recorded in the previous steps, the splicing joint is finally fine-tuned, and local trimming is carried out for areas where the deviation exceeds 8 mm. Next, the road surface is cleaned and a curing agent is sprayed, and the coverage rate of the curing agent is not less than 95%. Finally, quality acceptance is carried out, and the inspection items include indicators such as flatness, elastic modulus, and crack resistance. It can only be delivered for use after all indicators are qualified. The natural curing technology adopted in this step avoids potential quality hazards that may be brought about by forced rapid hardening, and the final fine-tuning ensures the refined control of the splicing quality, which has an important impact on the long-term service performance of the project.

[0055] The following is a detailed description of the mathematical models or calculation processes involved in the present invention.

[0056] In step S01, the mathematical expression for calculating the deviation value by the double center measurement method is specifically represented as follows:

[0057]

[0058] In the formula, D is the deviation value between the geometric center line and the representative center line, with the unit of mm; X g is the transverse coordinate of the geometric center line of the bridge, with the unit of mm; Y g is the longitudinal coordinate of the geometric center line of the bridge, with the unit of mm; X r is the transverse coordinate of the representative center line of the bridge, with the unit of mm; Y r is the longitudinal coordinate of the representative center line of the bridge, with the unit of mm.

[0059] Among them, the parameter acquisition method is:

[0060] X g and Y g are directly obtained through total station measurement; X r and Y r are calculated by the least squares fitting algorithm. The specific calculation process is as follows: First, collect the coordinates of multiple sample points (X i , Y i ) at the junction of the existing bridge and the new bridge, then establish a linear equation Y = aX + b, and solve for the parameters a and b by minimizing the sum of the squared residuals to obtain the representative center line equation, and then calculate X r and Y r according to the longitudinal and transverse coordinates of the bridge.

[0061] In step S03, the calculation formula for the flatness value is specifically expressed as follows:

[0062] F = max{h i}-min{h i}+σ h ;

[0063] In the formula, F is the flatness value of the bottom of the groove, with the unit of mm; h i is the elevation value of the i-th measuring point at the bottom of the groove, with the unit of mm; σ h is the standard deviation of elevation measurement, with the unit of mm.

[0064] Among them, the method for obtaining parameters is:

[0065] h i is directly obtained by measuring the elevation along the bottom of the groove every 1 meter with an automatic level; σ h The calculation formula is where is the average value of the elevations of all measuring points at the bottom of the groove, and n is the total number of measuring points.

[0066] In step S04, the calculation formula for the brushing thickness of the epoxy binder is specifically expressed as follows:

[0067] T e = T0 + α·F;

[0068] In the formula, T e is the brushing thickness of the epoxy binder, with the unit of mm; T0 is the reference thickness, with a value of 1.5 mm; α is the thickness adjustment coefficient, with a value of 0.2; F is the flatness value of the bottom of the groove calculated in step S03, with the unit of mm.

[0069] In step S05, the calculation formula for the placement position of the seismic rubber pad is specifically expressed as follows:

[0070] P r = P g + β·D·sgn(D);

[0071] In the formula, P r is the actual placement position coordinate of the seismic rubber pad, with the unit of mm; P g is the position coordinate of the geometric center line, with the unit of mm; β is the position adjustment coefficient, with a value of 0.5; D is the deviation value calculated in step S01, with the unit of mm; sgn(D) is the sign function of the deviation value, which takes a value of 1 when D is positive, indicating a deviation towards the new bridge direction; and takes a value of -1 when D is negative, indicating a deviation towards the old bridge direction.

[0072] In step S06, the calculation formula for the weighted center line is specifically expressed as follows:

[0073] P w = ω g ·P g + ω r ·P r ;

[0074] In the formula, P w is the coordinate of the weighted center line position, with the unit of mm; P g is the coordinate of the geometric center line position, with the unit of mm; P r is the coordinate of the representative center line position, with the unit of mm; ω g is the geometric center line weight coefficient; ω r is the representative center line weight coefficient, and it satisfies ω g + ω r = 1.

[0075] Among them, the calculation method of the weight coefficient is:

[0076]

[0077] In the formula, k n is the stiffness of the new bridge, with the unit of MPa; k o is the stiffness of the old bridge, with the unit of MPa. The stiffness ratio of the new and old bridges is obtained through the deflection test. The specific steps are as follows: First, select 3 measuring points on both the new bridge and the old bridge, and measure the deflection values under the action of a 100 kN standard axle load; then calculate the stiffness ratio according to the inverse relationship between the deflection and the stiffness.

[0078] In step S07, the calculation formula for the pouring compensation height of GD elastic concrete is specifically expressed as follows:

[0079] H c = 1.2·F + H0 + γ·L 2 ;

[0080] In the formula, H c is the pouring compensation height, with the unit of mm; F is the bottom flatness value calculated in step S03, with the unit of mm; H0 is the basic virtual arch height, and the value is 10 mm; γ is the span influence coefficient, and the value range is 0.001 - 0.005, with the unit of mm / square meter; L is the span length where the splicing joint is located, with the unit of meter.

[0081] Among them, the determination method of the γ value is: For different span lengths L, the corresponding γ values are calculated through finite element simulation respectively, a γ - L relationship curve is established, and then the γ value corresponding to the span is obtained through the interpolation method.

[0082] In step S08, the calculation formula for the joint line deviation is specifically expressed as follows:

[0083]

[0084] In the formula, δ is the deviation of the joint line shape, with the unit of mm; d j is the deviation value of the j-th measuring point, with the unit of mm; m is the total number of measuring points.

[0085] Among them, the calculation method of d j is as follows:

[0086] d j = |P a，j - P d，j |;

[0087] In the formula, P a，j is the actual position coordinate of the j-th measuring point, with the unit of mm; P d，j is the designed position coordinate of the j-th measuring point, with the unit of mm.

[0088] The construction principles and significance analysis of the above formulas are as follows:

[0089] The deviation value calculation formula uses the Euclidean distance to calculate the distance between two centerlines. This method is simple, intuitive and has high precision. It can comprehensively reflect the spatial position deviation situation, and makes the measurement results more accurate and reliable by introducing a coordinate system.

[0090] The flatness value calculation formula comprehensively considers two factors: the range and the dispersion. The range reflects the height difference between the highest point and the lowest point of the trough bottom, and the standard deviation reflects the overall undulation situation. The combination of the two can more comprehensively evaluate the flatness of the trough bottom and provide an accurate basis for the subsequent material usage.

[0091] The epoxy adhesive thickness calculation formula adopts a linear adjustment method, and dynamically adjusts the brushing thickness based on the flatness value. This method conforms to the basic principle in materials science that the rougher the surface, the thicker the adhesive layer. The coefficient 0.2 is the optimal value obtained through regression analysis of a large amount of engineering experimental data.

[0092] The rubber cushion block position calculation formula introduces the sign function to handle different offset directions, and adopts a 50% compensation coefficient to balance the difference between the theoretical position and the actual position, avoiding the deviation accumulation caused by completely relying on any centerline, and improving the stability of the vibration reduction effect.

[0093] The weighted centerline calculation formula is based on the stiffness distribution principle in structural mechanics, determines the weight through the bridge stiffness ratio, considers the influence of the structural characteristics difference between the new and old bridges on the splicing force, makes the splicing position more in line with the optimal mechanical state, and reduces the risk of stress concentration during the later use process.

[0094] The compensation height calculation formula comprehensively considers three factors: flatness, foundation virtual arch, and span influence. The span influence term adopts a quadratic function relationship to reflect the non-linear relationship between bridge deflection and span. The coefficient 1.2 takes into account the volume shrinkage after concrete compaction to ensure a flat final surface.

[0095] The linear deviation calculation formula uses the root mean square method to evaluate the overall linear quality of the splicing joint. Compared with the traditional single-point maximum deviation evaluation method, it can more objectively reflect the overall construction accuracy. Through the comprehensive evaluation of the deviations of all measuring points, it provides a comprehensive basis for the final adjustment.

[0096] Specifically, the principle of the present invention is as follows: The technical principle of the present invention is based on an in-depth understanding of the mechanism of settlement differences in bridge structures and the innovative application of flexible adaptability design. Its core lies in transforming the traditional static rigid connection into a dynamic flexible connection that can adapt to settlement differences, and effectively controlling the sudden change in height difference at the splicing point through three key technical links.

[0097] First, the present invention establishes an accurate positioning system based on actual settlement measurement. By distinguishing the geometric center line from the representative center line and quantifying the deviation value between the two, it accurately reflects the difference between the actual settlement state of the new and old bridges and the theoretical design. This difference is the fundamental cause of the sudden change in height difference. By measuring this deviation and introducing the concept of the weighted center line, the construction position can be dynamically adjusted according to the actual settlement state of the bridge, avoiding the height difference problem caused by traditional construction methods based only on design drawings.

[0098] Secondly, the constraint damping structure system adopted by the present invention forms an effective height difference transition mechanism. This system consists of seismic rubber pads and galvanized steel plates. The placement position of the seismic rubber pads is compensated and adjusted based on the deviation value, which can provide elastic support and deformation ability in the vertical direction; the galvanized steel plates ensure the connection strength in the horizontal direction, and their installation position is based on the weighted center line, comprehensively considering the theoretical position and the actual settlement state. This structural combination creates a flexible transition zone, effectively eliminating the impact effect caused by the sudden change in height difference.

[0099] Finally, the GD elastic concrete material used in the present invention is combined with dynamic construction control to form an overall solution that adapts to settlement differences. The GD elastic concrete has excellent elastic properties and can meet the deflection requirements generated by the up and down vibration when the vehicle passes by; during the construction process, the dynamic adjustment of the pouring height is guided by the flatness value, and the final fine adjustment is carried out according to the linear deviation of the joint, ensuring the flatness of the splicing joint in the initial state and the adaptability to settlement changes during long-term service.

[0100] In summary, through the organic combination of three major technical links, namely actual settlement measurement, constrained damping system, and application of elastic materials, the present invention has established a flexible splicing technology system capable of effectively addressing the settlement differences between new and old bridges, and solved the technical problem of sudden changes in road surface elevation at the splicing location.

[0101] A specific Embodiment 1 of the present invention is provided below. The specific implementation methods for each step in this Embodiment 1 are described in detail as follows.

[0102] The specific implementation method of step S01 is to accurately determine the construction boundary using the dual center measurement method. First, total stations are used to set measurement control points every 5 meters along the longitudinal direction of the bridge to obtain the geometric centerline of the theoretical joint position; then, the multi-point sampling method is adopted to collect the actual position data of at least 15 sample points at the junction of the existing bridge and the newly built bridge, and the representative centerline is calculated through the least squares fitting algorithm. The specific calculation process is to establish a linear equation Y = aX + b, and by minimizing the sum of squared residuals to solve for parameters a and b, obtaining the representative centerline equation; then calculate the deviation value between the two centerlines, and the calculation formula is where D is the deviation value, X g and Y g are the coordinates of the geometric centerline, X r and Y r are the coordinates of the representative centerline. If the deviation value exceeds the threshold of 15 mm, the measurement data needs to be rechecked; finally, based on the finally confirmed deviation value, using the geometric centerline as the benchmark, construction sidelines of 225 mm are released to both sides. The purpose of this step is to accurately determine the construction scope, ensure the accuracy of the subsequent grooving position, and prevent structural damage or insecure splicing caused by cutting too deep or too shallow. Through the calculation of the deviation value combined with the Euclidean distance algorithm, the spatial position deviation situation is comprehensively reflected, providing an accurate position reference for subsequent construction.

[0103] The specific implementation method of step S02 is to carry out notch opening using the layered cutting method. First, a diamond cutting machine is used to perform preliminary grooving along the construction sidelines, and the cutting depth is controlled at 70 mm; after the preliminary grooving is completed, a second cutting is carried out to control the total depth at 130 mm, and the cutting precision error is controlled within ±5 mm; then a hydraulic breaker is used to chisel the asphalt concrete paving layer within the cutting range in blocks to avoid damaging the surrounding structure; finally, a high-pressure air flow cleaning device is used to thoroughly clean the loose materials in the groove to ensure no impurities remain. The purpose of this step is to create good basic conditions for subsequent material construction, and the precise control of the cutting depth is the key to ensuring that the main structure of the bridge is not damaged. The layered cutting method is based on the material stress distribution theory, avoiding stress concentration and edge cracks caused by single deep cutting, and improving the grooving quality and precision.

[0104] The specific implementation of step S03 is to use precision leveling technology to process the bottom of the groove. First, use an automatic level to measure the elevation along the bottom of the groove every 1 meter and record the height difference data; according to the measurement data, calculate the flatness value, and the calculation formula is F = max{h i}-min{h i}+σ h , where F is the flatness value of the bottom of the groove, h i is the elevation value of the i-th measuring point at the bottom of the groove, and σ h is the standard deviation of the elevation measurement, and the calculation formula is where is the average value of the elevations of all measuring points at the bottom of the groove, n is the total number of measuring points. If the flatness value exceeds 8 mm, local trimming is required; then, lay a sand cushion layer with a thickness of 10 mm on the bottom of the groove to play a buffering role; then evenly spread fine aggregate concrete with a ratio of 1:2.5:3.5 on the sand cushion layer, and use a laser screed to monitor the surface height of the leveling layer in real time, and control the height difference between the two sides of the leveling layer not to exceed 2 mm; the depth of the leveling layer is kept at about 130 mm, and ensure that a 90-degree right angle is formed with the original paving layer. The flatness treatment of this step directly affects the splicing quality. By strictly controlling the levelness and depth of the leveling layer, a uniformly stressed base surface is provided for the subsequent materials. The flatness value calculation formula comprehensively considers two factors: the range and the dispersion, and can more comprehensively evaluate the flatness of the bottom of the groove, providing an accurate basis for the subsequent material consumption.

[0105] The specific implementation of step S04 is to adopt a multi-level surface treatment process to improve the interface bonding performance. First, use an air compressor gun with a pressure not less than 0.8 MPa to thoroughly remove the dust and impurities in the groove; then use a flame gun with a temperature of 180 - 220 °C to uniformly heat and dry the inner surface of the groove, and the heating time is not less than 5 minutes until there is no obvious moisture on the surface; then, according to the flatness value measured in the previous step, calculate the coating thickness of the epoxy adhesive, and the calculation formula is T e = T0 + α·F, where T e is the coating thickness of the epoxy adhesive, T0 is the reference thickness, with a value of 1.5 mm, α is the thickness adjustment coefficient, with a value of 0.2, and F is the flatness value of the bottom of the groove calculated in step S03; then use a coating tool to evenly coat the epoxy adhesive to ensure that all inner surfaces of the groove are covered; finally, paste a rubber water stop with a width of 50 mm along the inner side wall of the groove, and the pasting height is not more than 20 mm from the top of the groove. This process effectively prevents water intrusion in the later stage and improves the overall waterproof performance of the splicing structure through surface treatment and the application of an interface adhesive. The epoxy adhesive thickness calculation formula adopts a linear adjustment method, dynamically adjusting the coating thickness based on the flatness value, which conforms to the basic principle in materials science that the rougher the surface, the thicker the adhesive layer. The coefficient 0.2 is the optimal value obtained through engineering experimental data analysis.

[0106] The specific implementation of step S05 is to achieve constrained damping installation by adopting a double-layer buffer structure design. First, calculate the optimal placement position of the seismic rubber pads according to the deviation value. The calculation formula is P r = P g + β·D·sgn(D), where P r is the actual placement position coordinate of the seismic rubber pad, P g is the geometric center line position coordinate, β is the position adjustment coefficient with a value of 0.5, D is the deviation value calculated in step S01, sgn(D) is the sign function of the deviation value, taking a value of 1 when D is positive, indicating a deviation towards the new bridge direction, and taking a value of -1 when D is negative, indicating a deviation towards the old bridge direction; then place the 200mm×500mm×20mm seismic rubber pads with a Shore A hardness of 60 - 70 at the adjusted position to ensure that the center of the pads is aligned with the weighted center line; then precisely place a 200mm×250mm×20mm steel plate on the seismic rubber pads. The steel plate is made of Q345B and its surface is subjected to anti-corrosion treatment; at the same time, apply a layer of structural adhesive with a thickness of 0.5mm on the contact surface between the rubber pad and the steel plate to enhance the connection stability between the two. The constrained damping system constructed in this step is based on the vibration reduction principle of material mechanics. Through the elastic deformation of the rubber pads, the vibration energy is absorbed, and the steel plates provide stiffness constraints, jointly reducing the sudden change in height difference caused by the settlement difference between the new and old bridges. The symbol function is introduced into the rubber pad position calculation formula to handle different deviation directions, and a 50% compensation coefficient is used to balance the difference between the theoretical position and the actual position, avoiding the deviation accumulation caused by relying entirely on either center line, and improving the stability of the vibration reduction effect.

[0107] The specific implementation of step S06 is to install galvanized steel plates by adopting distributed fixing technology. First, calculate the geometric center line and the weighted center line representing the center line. The calculation formula is P w = ω g ·P g + ω r ·P r , where P w is the weighted center line position coordinate, P g is the geometric center line position coordinate, P r is the representative center line position coordinate, ω g is the geometric center line weight coefficient, ω r is the representative center line weight coefficient, and it satisfies ω g + ω r = 1. The calculation method of the weight coefficient is and where k n is the stiffness of the new bridge, k oThe stiffness of the old bridge is [old_bridge_stiffness], and the stiffness ratio of the new and old bridges is obtained through deflection tests. Then, four hot-dip galvanized steel plates with dimensions of 200mm×500mm×6mm are arranged along the weighted centerline, with an overlapping length of 50mm between adjacent steel plates. Next, M30 high-strength bolts are installed at the reserved hole positions of the steel plates, and each steel plate has no less than 4 fixing points. The tightening torque of the bolts is controlled between 120 and 140 N·m, and flat washers and spring washers are placed under the bolts. Finally, a structural sealant with a thickness of 1mm is applied at the overlapping joints of adjacent steel plates to ensure the tightness of the joints. This step arranges galvanized steel plates along the scientifically calculated weighted centerline and combines high-strength fixed connections to form a stable joint covering structure, providing a reliable bearing foundation for the upper elastic material. The weighted centerline calculation formula is based on the stiffness distribution principle in structural mechanics, determines the weights through the bridge stiffness ratio, and considers the influence of the structural characteristic differences between the new and old bridges on the joint forces, making the joint position more in line with the optimal mechanical state and reducing the risk of stress concentration during later use.

[0108] The specific implementation method of step S07 is to construct GD elastic concrete using the temperature-controlled pouring process. First, anti-pollution tapes with a width of 40mm are pasted on both sides outside the trench to prevent the elastic concrete from polluting the surrounding road surface. Then, GD elastic concrete is mixed at the concrete mixing plant according to the mixing ratio requirements, and the mixing temperature is controlled between 15 and 25°C, and the mixing time is not less than 90 seconds. Next, the compensation height is calculated according to the flatness value, and the calculation formula is H c = 1.2·F + H0 + γ·L 2 , where H c is the pouring compensation height, F is the flatness value of the trench bottom calculated in step S03, H0 is the basic virtual arch height, with a value of 10mm, γ is the span influence coefficient, with a value range of 0.001 - 0.005, unit of mm / m², and L is the span length where the joint is located, unit of meter. After the mixed GD elastic concrete is transported to the site, it is immediately poured into the trench until the pouring height reaches the calculated compensation height. Subsequently, a small roller with a weight of 1 - 2 tons is used for at least 8 passes of compaction to ensure that the surface flatness error does not exceed 3mm; the compaction coefficient is not less than 0.98. The temperature-controlled pouring process adopted in this step ensures the fluidity and workability of GD elastic concrete, and the accurate calculation of the compensation height guarantees the flatness after final compaction, which is the core link of the entire joint process. The compensation height calculation formula comprehensively considers three factors: flatness, basic virtual arch, and span influence. The span influence term uses a quadratic function relationship to reflect the non-linear relationship between bridge deflection and span, and the coefficient 1.2 considers the volume shrinkage of the concrete after compaction to ensure the final surface flatness.

[0109] The specific implementation of step S08 is to adopt a fine surface treatment technology to improve the splicing quality. First, after the GD elastic concrete begins to set, use a heater with a temperature of 130 - 150 °C to perform thermal joint treatment on the edge, and the heating width is 30 mm; then use a troweling tool to finely level the surface, and the leveling pressure is controlled at 0.05 - 0.1 MPa; then use a high-precision level to detect the joint width to ensure that the width error does not exceed 5 mm; measure the height difference between the joint and the paving surface with a straightedge and a level, and adjust it to less than ±2 mm; finally, use an electronic total station to measure along the joint every 2 meters, record the joint line deviation data, and the calculation formula is where δ is the joint line deviation, d j is the deviation value of the j-th measuring point, and the calculation method is d j =|P a，j -P d，j |, P a，j is the actual position coordinate of the j-th measuring point, P d，j is the designed position coordinate of the j-th measuring point, m is the total number of measuring points, and the line deviation is controlled within 10 mm. The surface finishing technology adopted in this step ensures the flatness and line beauty of the splicing joint, and the thermal joint treatment enhances the compactness and durability of the edge part, which is an important link in engineering quality control. The line deviation calculation formula uses the root mean square method to evaluate the overall line quality of the splicing joint. Compared with the traditional single-point maximum deviation evaluation method, it can more objectively reflect the overall construction accuracy and provide a comprehensive basis for the final adjustment.

[0110] The specific implementation of step S09 is to complete the construction by combining natural curing and final adjustment. First, under the fully enclosed state, naturally cool the completed splicing structure, and the cooling time is not less than 2 hours, and the ambient temperature should be between 10 - 30 °C; monitor the surface temperature of the GD elastic concrete during the cooling period, and the next operation can be carried out only when the surface temperature drops below 40 °C; then, according to the previously recorded joint line deviation data, make a final fine adjustment to the splicing joint, and perform local trimming on the area where the deviation exceeds 8 mm; then carry out road surface cleaning and spraying of curing agent, and the coverage rate of the curing agent is not less than 95%; finally, conduct quality acceptance, and the inspection items include indicators such as flatness, elastic modulus, and crack resistance performance. It can be delivered for use only after all indicators are qualified. The natural curing technology adopted in this step avoids the quality hidden dangers that may be brought by forced rapid hardening, and the final fine adjustment ensures the fine control of the splicing quality, which has an important impact on the long-term service performance of the project. The natural curing method is based on the temperature gradient theory in materials science, controls the internal stress concentration caused by rapid cooling, and improves the overall stability and durability of the structure.

[0111] During the entire construction process of the flexible splicing of elastic concrete for new and old bridges, there are multiple precise calculation and control processes. The deviation value calculation formula The Euclidean distance algorithm is adopted to accurately quantify the spatial deviation between two centerlines, providing a position reference for subsequent construction. The flatness value calculation formula is F = max{h i}-min{h i}+σ h which comprehensively considers the extreme value difference and data dispersion, and comprehensively evaluates the surface flatness condition. The epoxy binder thickness calculation formula is T e = T0 + α·F, establishing a linear relationship between thickness and flatness, and realizing the intelligent adjustment of material usage. The rubber pad position calculation formula is P r = P g + β·D·sgn(D), which processes the directionality problem through the sign function, making the position compensation more reasonable. The weighted centerline calculation formula is P w = ω g ·P g + ω r ·P r Based on the stiffness weight principle, it optimizes the mechanical properties of the splicing position. The compensation height calculation formula is H c = 1.2·F + H0 + γ·L 2 Considering multiple influencing factors, it ensures the final surface flatness. The linear deviation calculation formula adopts the root mean square evaluation method, providing an overall quality evaluation index. The scientific design and precise implementation of these calculation processes jointly ensure the construction quality and service performance of the new-old bridge splicing, providing an effective solution to the joint damage problem in traditional splicing methods.

[0112] The core innovation of this new-old bridge elastic concrete flexible splicing construction method lies in the combination of an accurate measurement and positioning system, an advanced material vibration damping principle, and a scientific construction control algorithm. Through flexible connection, it realizes the effective transition of the new-old bridge structures, avoiding the problems of stress concentration and cracking easily generated by traditional rigid connections. Especially the combined application of elastic concrete and constrained damping structures enables the splicing joint to have the ability to absorb deformation, reduce vibration, and adapt to uneven settlement, significantly improving the bridge operation safety and service life, and having important practical value for large-scale road reconstruction and expansion projects. This method realizes the whole-process control from measurement and positioning to final acceptance through refined construction steps. Each step has clear technical parameters and quality control indicators, ensuring the reliability and consistency of construction quality, and having strong engineering application and promotion value.

[0113] It should be noted that the detailed explanations of the variables involved in the present invention are shown in Table 1 below.

[0114] Table 1 Variable Explanation Table

[0115]

[0116]

[0117] The following provides a specific Embodiment 2 of the present invention. The specific implementation manners of each step in this Embodiment 2 are described in detail as follows.

[0118] Preparation work: Consult drawings and relevant materials to comprehensively understand the project requirements and technical details; contact relevant material suppliers in advance to ensure the timely supply of construction materials; determine a reasonable construction traffic organization method in combination with the actual site conditions to ensure smooth traffic during construction; reasonably arrange the construction progress plan to clarify the construction tasks and time nodes at each stage; do a good job in the preparation work for the entry of materials and equipment to ensure that the material quality is qualified and the equipment performance is good.

[0119] Measurement and lofting: According to the center position of the joint, use professional measuring instruments to accurately release the center line of the joint; based on the center line, measure 225 mm to both sides to release the construction sidelines, providing accurate boundaries for subsequent construction.

[0120] Grooving and cleaning: According to the released construction line, use a cutting machine to groove, and control the cutting depth at about 130 mm to avoid over-cutting and damaging the beam body; chisel and clean all the asphalt concrete pavement layers within the cutting range to ensure that there are no sundries in the groove.

[0121] Leveling treatment in the groove: Level the bottom surface of the groove with fine aggregate concrete to make the height of the leveling layers on both sides of the joint on the same plane and keep the depth at about 130 mm to ensure good stress conditions of the joint; use an air compressor gun to clean the sundries in the groove, and then use a flame gun for drying treatment; apply epoxy adhesive in the groove after treatment, and paste a rubber waterstop to play a waterproof role and enhance the bonding between the GD elastic concrete and the pavement layers on both sides.

[0122] Installation of constrained damping: Set constrained damping at the galvanized steel plate, place a 200 mm * 500 mm * 20 mm seismic rubber pad in the center to cover the joint; cover the seismic rubber pad with a 200 mm * 250 mm * 20 mm steel plate. The steel plate and the pad are both pre-drilled with Φ30 holes at the center position 100 mm from both sides.

[0123] Fixing the steel plate to cover the joint: The steel plate for covering the joint is centered and covered with 4 pieces of 200 mm * 500 mm * 6 mm galvanized steel plates to ensure that the center line of the covering steel plate coincides with the joint; for connection and fixation, use M30 bolts to pass through the pre-drilled holes to connect the upper and lower layers of steel plates and the seismic pad through the holes. At the lower opening, use flat washers, spring washers, and 2 nuts for fixation, and bond the two nuts with welding glue.

[0124] GD elastic concrete pouring: Stick anti-pollution tapes on both sides outside the trench to prevent pollution of the surrounding area during concrete pouring; Pour the prepared GD elastic concrete into the trench, slightly higher than the top surface of the trench, leaving a certain amount of virtual throw; After pouring, quickly compact it with a small roller.

[0125] Surface treatment: After completing the elastic joint, perform heat joint treatment on the side; Smooth the surface to make the width of the joint neat, the surface flat, and the height difference between the joint and the paving surface less than ±2 mm.

[0126] Cooling treatment: After the construction is completed in a fully enclosed state, let it cool naturally for no less than 2 hours, and deliver it for use after cooling.

[0127] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention.

Claims

1. A flexible splicing construction method for elastic concrete of new and old bridges, characterized in that: include: Measure and lay out according to the center position of the joint, accurately lay out the geometric center line and representative center line of the joint, measure the deviation value between the geometric center line and the representative center line, and lay out the construction edge line on both sides of the geometric center line according to the deviation value; cut grooves along the construction edge lines and clean them; level the bottom surface of the groove and measure the flatness value; dry the groove after cleaning, apply epoxy adhesive and paste rubber water stop; set restrained damping at the joint, place seismic rubber pads and steel plates; use galvanized steel plates to cover the seams in the center, and the center line of the galvanized steel plates coincides with the weighted center line of the geometric center line and the representative center line and is fixed; pour GD elastic concrete into the groove and compact it; perform hot joint and surface treatment on the GD elastic concrete, and measure and record the joint linear deviation; After the GD elastic concrete cools naturally, final adjustments are made based on the joint linear deviation; the deviation value is used to correct the construction position to adapt to the actual deformation.

2. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 1 is characterized in that: The step of measuring and laying out according to the center position of the joint, accurately laying out the geometric center line of the joint and the representative center line of the joint, measuring the deviation value between the geometric center line and the representative center line, and laying out the construction side lines on both sides of the geometric center line according to the deviation value, in which a 225mm construction side line is laid out on both sides of the geometric center line according to the deviation value.

3. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 2 is characterized in that: The steps of setting constraint damping at the joints and placing seismic rubber pads and steel plates include: setting constraint damping at the joints, covering the joints with seismic rubber pads of 200mm×500mm×20mm, placing a steel plate of 200mm×250mm×20mm on the upper layer, and compensating and adjusting the placement position of the seismic rubber pads based on the deviation value.

4. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 3 is characterized in that: The steps of using galvanized steel plates to cover the seams in the center, coinciding the center lines of the galvanized steel plates with the geometric center line and the weighted center line representing the center line and fixing them include: using 4 200mm×500mm×6mm galvanized steel plates to cover the seams in the center, coinciding the center lines of the galvanized steel plates with the geometric center line and the weighted center line representing the center line, and fixing them with M30 bolts through holes.

5. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 4 is characterized in that: The geometric center line refers to the center line of the theoretical splicing position determined by measurement based on the bridge structure design drawings, and is directly measured by a measuring instrument.

6. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 5 is characterized in that: The representative center line refers to the center line of the actual splicing position after taking into account actual construction errors and bridge settlement, and is obtained through multi-point sampling measurement.

7. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 6 is characterized in that: The weighted center line refers to the optimal splicing line determined after weighted calculation based on the geometric center line and the representative center line, taking into account the bridge stiffness and expected deformation, and is used to guide the final installation position of the galvanized steel plate.

8. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 7 is characterized in that: The steps of pouring and compacting the GD elastic concrete into the groove include: sticking anti-fouling tapes on both sides of the outer groove, pouring the mixed GD elastic concrete into the groove, the pouring height is slightly higher than the groove top surface according to the compensation height calculated according to the flatness value, and compacting it with a small roller.

9. The flexible splicing construction method of elastic concrete of new and old bridges according to claim 8 is characterized in that: The steps of performing hot joint treatment and surface treatment on the GD elastic concrete and measuring and recording the joint linear deviation include: performing hot joint treatment on the sides of the GD elastic concrete, smoothing the surface to ensure that the joint width is uniform, the surface is flat, the height difference between the joint and the paved surface is less than ±2mm, and measuring and recording the joint linear deviation.

10. A flexible splicing construction method for elastic concrete of new and old bridges according to claim 9, characterized in that: The step of making a final adjustment according to the joint linear deviation after the GD elastic concrete is naturally cooled comprises: making a final adjustment according to the joint linear deviation after the GD elastic concrete is naturally cooled for not less than 2 hours in a fully closed state.

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