A linear control method for asynchronous construction of a PK-section composite beam cable-stayed bridge

Abstract

The present invention relates to the technical field of bridge engineering, and in particular to a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge. During the manufacturing process, the present invention pre-assembles and manufactures in batches to accurately control the manufacturing accuracy and ensure the accurate alignment of the PK-section composite girder segment during manufacturing; during the transportation process, the PK-section composite girder segment manufacturing is reinforced and cushioned to prevent deformation of the PK-section composite girder segment; during the hoisting process, the reverse jacking method is used to ensure the same transverse alignment of the PK-section composite girder segment to be hoisted and the already hoisted PK-section composite girder segment; during the subsequent construction process, the hoisting elevation positioning points are continuously measured. Even if the hoisting elevation positioning points shift due to the change in the bridge stiffness, the longitudinal alignment can be adjusted by tensioning the stay cables.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge. Background Art

[0002] Steel-concrete composite girder cable-stayed bridges have become one of the main bridge types for long-span bridges due to the full utilization of the tensile performance of steel and the compressive performance of concrete. For the PK section, compared with I-beams or box sections, due to its unique inverted trapezoidal design, its wind resistance stability is relatively excellent.

[0003] At present, the construction methods of PK-section composite girder cable-stayed bridges mainly include two types: traditional construction methods and asynchronous construction methods. The traditional construction method mainly requires the PK-section composite girder segments to be pre-laminated in the factory and then hoisted as a whole after being transported to the site. Due to the excessive transportation and hoisting weight, its application scenarios are limited.

[0004] The construction steps of the asynchronous construction method are mainly as follows: When constructing by cantilever, hoist the N# steel girder, hoist the deck slab of the N-2# beam segment, initially tension the N# stay cables, move the crane forward to the N# beam segment, pour the wet joint of the N-2# beam segment and tension the N-2# stay cables for the second time, and so on to complete the asynchronous construction of the cable-stayed bridge.

[0005] However, when the asynchronous construction method is adopted, due to the post-laminated construction method of the deck slab, the PK-section composite girder segment is in an open state before lamination. At this time, the cross-sectional lateral stiffness of the PK-section composite girder segment is small, and it is easy to deform during transportation or hoisting, thus affecting the final alignment of the bridge. Secondly, due to the influence of the deck crane load and the deck slab load, during the hoisting process, the already hoisted main girder will have a downward displacement transversely, and the beam segment to be hoisted has not deformed, resulting in a transverse height difference, making it difficult to ensure the transverse alignment consistency of each beam segment. Finally, since the deck slab and the main girder are constructed asynchronously, the stiffness of the main girder will also change before and after the lamination of the deck slab, resulting in a change in the longitudinal alignment of the bridge and making it difficult to control effectively.

[0006] In view of this, it is necessary to propose a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge to solve or at least alleviate the above defects. Summary of the Invention

[0007] The main purpose of the present invention is to provide a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge to solve the technical problem that it is difficult to control the bridge alignment during the asynchronous construction in the prior art.

[0008] To achieve the above purpose, the present invention provides a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge, including the following steps:

[0009] S1. At the pylon, construct the combined beam segment of the i-th PK section and assemble the deck crane; where i ≥ 1, i is a positive integer, and the starting value of i is 1.

[0010] S2. Obtain the theoretical positioning elevation of the hoisting elevation positioning point of the combined beam segment of the (i + 1)-th PK section, use the deck crane to hoist the combined beam segment of the (i + 1)-th PK section, and after hoisting and positioning the combined beam segment of the (i + 1)-th PK section according to the theoretical positioning elevation, temporarily fix the combined beam segment of the (i + 1)-th PK section.

[0011] S3. Obtain the deformation area of the combined beam segment of the i-th PK section after assembling the deck crane, and jack up the combined beam segment of the (i + 1)-th PK section to a position matching the deformation area by means of reverse jacking, so that the transverse alignment of the combined beam segment of the (i + 1)-th PK section matches the transverse alignment of the combined beam segment of the i-th PK section, and then permanently fix the combined beam segment of the (i + 1)-th PK section to complete the hoisting of the combined beam segment of the (i + 1)-th PK section.

[0012] S4. Judge whether the combined beam segment of the (i + 1)-th PK section is the last combined beam segment of the PK section. If so, complete the asynchronous construction of the cable-stayed bridge; if not, assign i + 1 to i and return to step S2.

[0013] Further, the step S3 specifically includes the following steps:

[0014] S31. Obtain the deformation area of the combined beam segment of the i-th PK section after assembling the deck crane, and fix it on the combined beam segment of the i-th PK section with a jack, which is used to apply an external force to the area corresponding to the deformation area in the combined beam segment of the (i + 1)-th PK section.

[0015] S32. The jack gradually jacks up the combined beam segment of the (i + 1)-th PK section from the side web position of the combined beam segment of the i-th PK section towards the middle of the bridge, and then plates and temporarily welds and fixes the jacked-up area; where the reverse jacking sequence is the side web, the bottom plate, the middle web and the small longitudinal beam in turn until the transverse alignment of the combined beam segment of the (i + 1)-th PK section is jacked up to match the deformation area; where the combined beam segment of the PK section includes a bottom plate, side webs, a middle web and small longitudinal beams.

[0016] S33. Then permanently fix the combined beam segment of the (i + 1)-th PK section to complete the hoisting of the combined beam segment of the (i + 1)-th PK section.

[0017] Preferably, after the step S4, the following steps are further included:

[0018] S5. Measure the hoisting elevation positioning points of the (N - 2)th, (N - 1)th, and Nth PK-section composite beam segments in sequence to obtain the measured elevations of the three PK-section composite beam segments, where N is greater than or equal to 2.

[0019] S6. Compare the measured elevations with the theoretical positioning elevations of the corresponding PK-section composite beam segments respectively to obtain the first error value of the (N - 2)th PK-section composite beam segment, the second error value of the (N - 1)th PK-section composite beam segment, and the third error value of the Nth PK-section composite beam segment. If the first error value, the second error value, and the third error value are all within the range of ±20 mm, the longitudinal alignment control is completed; if the first error value, the second error value, and the third error value do not all meet the requirement of being within the range of ±20 mm, go to step S7.

[0020] S7. Take the PK-section composite beam segments with error values outside the range of ±20 mm as the cable length adjustment objects, take the direction from the (N - 2)th PK-section composite beam segment to the Nth PK-section composite beam segment as the cable length adjustment sequence, adjust the cable lengths of the corresponding stay cables of the PK-section composite beam segments in sequence, and return to step S6.

[0021] Further preferably, steps S5 - S7 are completed before the wet joint construction stage of the (N - 2)th PK-section composite beam segment, where the wet joint construction stage of the (N - 2)th PK-section composite beam segment is one of the asynchronous construction stages of the bridge.

[0022] Further preferably, after step S7, the following steps are further included:

[0023] S81. Obtain the design temperature, collect weather information, and formulate a closure plan, where the closure of the side span and the middle span is carried out on a cloudy day or at night when the temperature is equal to the design temperature.

[0024] S82. Calculate the cable forces of the bridge to obtain the theoretical values.

[0025] S83. Measure the cable forces of the bridge on site to obtain the measured values, and calculate the deviation values between the measured values and the theoretical values.

[0026] S84. When the deviation value is outside the range of ±5%, it is determined that the cable force is non-compliant, and the cable length is adjusted to adjust the cable force, and then return to step S82.

[0027] S85. When the deviation value is within the range of ±5%, it is determined that the cable force is compliant, and the closure of the side span and the middle span is carried out.

[0028] Preferably, before step S1, the following steps are further included:

[0029] S01. Obtain the design drawings of the bridge, and determine the positions of the crane support points and the hoisting elevation positioning points according to the said design drawings.

[0030] S02. Determine the first stress-free longitudinal manufacturing alignment, the first stress-free included angle, and the first transverse pre-camber value of each PK section composite beam segment.

[0031] S03. Manufacture the PK section composite beam segments according to the first stress-free longitudinal manufacturing alignment, the first stress-free included angle, and the first transverse pre-camber value.

[0032] Further preferably, after the step S03, the following steps are further included:

[0033] S04. Perform pre-assembly on the manufactured PK section composite beam segments, and obtain the second stress-free longitudinal manufacturing alignment, the second stress-free included angle, and the second transverse pre-camber value of the pre-assembled PK section composite beam segments.

[0034] S05. Judge whether the deviation between the second stress-free longitudinal manufacturing alignment and the first stress-free longitudinal manufacturing alignment is within the first preset range, judge whether the deviation between the second stress-free included angle and the first stress-free included angle is within the second preset range, and judge whether the deviation between the second transverse pre-camber value and the first transverse pre-camber value is within the third preset range.

[0035] S06. When all three of the deviation between the second stress-free longitudinal manufacturing alignment and the first stress-free longitudinal manufacturing alignment being within the first preset range, the deviation between the second stress-free included angle and the first stress-free included angle being within the second preset range, and the deviation between the second transverse pre-camber value and the first transverse pre-camber value being within the third preset range are satisfied, determine that the PK section composite beam segments meet the manufacturing accuracy conditions.

[0036] Further preferably, the theoretical positioning elevation in the step S2 is specifically obtained through the following steps:

[0037] When the PK section composite beam segments meet the manufacturing accuracy conditions, obtain the weight of the PK section composite beam segments; calculate the support reaction force according to the weight of the PK section composite beam segments and the positions of the crane support points, and determine the theoretical positioning elevation of the hoisting elevation positioning points when the PK section composite beam segments are hoisted according to the support reaction force.

[0038] Further preferably, the step S03 specifically includes the following steps:

[0039] S031. Manufacture a jig suitable for the assembly of the PK section composite beam segments, and establish a local coordinate system for the assembly of the PK section composite beam segments; wherein, the coordinate directions of the local coordinate system are consistent with the coordinate directions of the bridge.

[0040] S032. Manufacture the first M PK cross-section composite beam segments before manufacturing. Taking the center of the first PK cross-section composite beam segment at the cable tower position of the bridge as the zero point, calculate the three-dimensional relative coordinates between adjacent PK cross-section composite beam segments, and use the jig to pre-assemble the first M PK cross-section composite beam segments to obtain the pre-assembled PK cross-section composite beam segments; where M is greater than or equal to 1.

[0041] S033. Compare the height of the hoisting elevation positioning point of the pre-assembled PK cross-section composite beam segment with the theoretical positioning elevation. After determining that the error is within the range of ±10 mm, perform hole opening and welding groove cutting on the pre-assembled PK cross-section composite beam segment.

[0042] S034. Remove the first M - 1 PK cross-section composite beam segments, and taking the Mth PK cross-section composite beam segment as the reference, manufacture and pre-assemble the second batch of PK cross-section composite beam segments, and repeat steps S032 to S033 until all PK cross-section composite beam segments are manufactured.

[0043] Further preferably, it also includes linear control during the transportation process of the PK cross-section composite beam segment, and the specific steps are as follows:

[0044] Fix the profiled steel at the top plate of each PK cross-section composite beam segment respectively, and set temporary cushions at the positions of the anchor points and hoisting points, and then transport the PK cross-section composite beam segment to the construction site; where the PK cross-section composite beam segment includes a top plate, and anchor points and hoisting points are arranged on the top plate.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] After the hoisting of the PK cross-section composite beam segment is completed, the stiffness of the PK cross-section composite beam segment will increase. Due to factors such as the deck crane, there is a large load on the hoisted PK cross-section composite beam segment, causing the hoisted PK cross-section composite beam segment to deform laterally. The present invention makes the lateral alignment of the later hoisted PK cross-section composite beam segment match the lateral alignment of the previous PK cross-section composite beam segment through the method of jacking from the bottom, so as to ensure that the lateral alignment of each PK cross-section composite beam segment is consistent, and under cyclic construction, the overall lateral alignment of the bridge is controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0048] Figure 1Schematic diagram of the overall bridge structure during the hoisting operation of the PK section composite girder segment in an embodiment of the present invention;

[0049] Figure 2 Schematic diagram of the local bridge structure during the hoisting operation of the PK section composite girder segment in an embodiment of the present invention;

[0050] Figure 3 Top view of the bridge during the hoisting operation of the PK section composite girder segment in an embodiment of the present invention;

[0051] Figure 4 Front view of the overall structure of the PK section composite girder segment during the pre-assembly process of the PK section composite girder segment in an embodiment of the present invention;

[0052] Figure 5 Top view of the overall structure of the PK section composite girder segment during the pre-assembly process of the PK section composite girder segment in an embodiment of the present invention;

[0053] Figure 6 Flowchart of the method for controlling the transverse alignment of the PK section composite girder segment in an embodiment of the present invention.

[0054] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings.

[0055] Explanation of the reference numerals in the drawings:

[0056] 1. Bridge; 2. Cable-stayed cable; 3. Deck crane; 4. The Nth PK section composite girder segment; 41. Cross beam; 42. Middle web; 43. Side web; 44. Top plate; 45. Small longitudinal beam; 46. Bottom plate; 5. The (N - 1)th PK section composite girder segment; 6. The (N - 2)th PK section composite girder segment; 7. PK section composite girder segment with the bridge deck laminated; 8. Crane support point; 9. Hoisting elevation positioning point; 10. Bracket; 11. Temporary support; 12. Section steel. Detailed implementation manners

[0057] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0058] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0059] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as described in the attached drawings). If the specific posture changes, the directional indications will also change accordingly.

[0060] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0061] Please refer to Figures 1 to 6 , this embodiment provides a linear control method for asynchronous construction of a PK-section composite girder cable-stayed bridge. This embodiment mainly controls the transverse linearity of the bridge 1, including the following steps:

[0062] S1, construct the i-th PK-section composite girder segment at the cable tower and assemble the deck crane 3; where i≥1, i is a positive integer, and the starting value of i is 1.

[0063] S2, obtain the theoretical positioning elevation of the hoisting elevation positioning point 9 of the (i + 1)-th PK-section composite girder segment, use the deck crane 3 to perform hoisting operations on the (i + 1)-th PK-section composite girder segment, after hoisting and positioning the (i + 1)-th PK-section composite girder segment according to the theoretical positioning elevation, then temporarily fix the (i + 1)-th PK-section composite girder segment. The hoisting and positioning should be carried out when the temperature is stable at night. After completing the hoisting and positioning, use drift pins or welding to make temporary fixation on both sides of the PK-section composite girder segment. The error between the actual height of the hoisting elevation positioning point 9 and the theoretical positioning elevation during hoisting and positioning should be controlled within ±10 mm.

[0064] The process of obtaining the theoretical positioning elevation is as follows: when the PK-section composite girder segment meets the manufacturing accuracy conditions, obtain the weight of the PK-section composite girder segment; calculate the support reaction force according to the weight of the PK-section composite girder segment and the position of the crane support point 8, and determine the theoretical positioning elevation of the hoisting elevation positioning point 9 when the PK-section composite girder segment is hoisted according to the support reaction force. The calculation process of the support reaction force in this embodiment belongs to the prior art and will not be elaborated here.

[0065] S3. Obtain the deformation area of the i-th PK-section composite girder segment after assembling the deck crane 3, and jack up the (i + 1)-th PK-section composite girder segment to a position matching the deformation area by means of reverse jacking, so that the transverse alignment of the (i + 1)-th PK-section composite girder segment matches the transverse alignment of the i-th PK-section composite girder segment, and then permanently fix the (i + 1)-th PK-section composite girder segment to complete the hoisting of the (i + 1)-th PK-section composite girder segment; where i is greater than or equal to 1 and i is a positive integer.

[0066] Specifically, in S31, obtain the deformation area of the i-th PK-section composite girder segment after assembling the deck crane 3, and fix it on the i-th PK-section composite girder segment by using a jack, which is used to apply an external force to the area corresponding to the deformation area in the (i + 1)-th PK-section composite girder segment.

[0067] S32. The jack gradually jacks up the (i + 1)-th PK-section composite girder segment from the position of the side web 43 of the i-th PK-section composite girder segment towards the middle of the bridge 1, and then plates and temporarily welds and fixes the jacked-up area; among them, the reverse jacking sequence is the side web 43, the bottom plate 46, the middle web 42 and the small longitudinal beam 45 in turn, until the transverse alignment of the (i + 1)-th PK-section composite girder segment is jacked up to match the deformation area. For example, the height of the top surface of the side web 43 of the (i + 1)-th PK-section composite girder segment is flush with the height of the top surface of the side web 43 in the deformation area of the i-th PK-section composite girder segment; where the PK-section composite girder segment includes a bottom plate 46, a cross beam 41, side webs 43, middle webs 42 and small longitudinal beams 45. As Figure 4 and Figure 5 shown, the bottom plate 46 is arranged at the bottom of the PK-section composite girder segment, the side webs 43 are arranged on both sides of the bottom plate 46, the small longitudinal beams 45 are located in the center of the PK-section composite girder segment, the middle webs 42 are arranged between the small longitudinal beams 45 and the side webs 43, the side webs 43 and the middle webs 42 are perpendicular to the bottom plate 46 and fixedly connected to the bottom plate 46, and the cross beam 41 is fixed on the other side of the side web 43 opposite to the bottom plate 46, and the cross beam 41 is fixedly connected to the side web 43, the middle web 42 and the small longitudinal beam 45 in turn. The plate is to place a steel plate in the jacked-up area to connect the i-th PK-section composite girder segment and the (i + 1)-th PK-section composite girder segment.

[0068] S33. Then permanently fix the (i + 1)-th PK-section composite girder segment to complete the hoisting of the (i + 1)-th PK-section composite girder segment.

[0069] S4. Judge whether the (i + 1)-th PK-section composite girder segment is the last PK-section composite girder segment. If so, complete the asynchronous construction of the cable-stayed bridge; if not, assign i + 1 to i and return to step S2.

[0070] In one embodiment, it further includes the manufacturing process of the PK cross-section composite beam segment and conducts alignment control on the manufactured PK cross-section composite beam segment. The specific process is as follows:

[0071] S01, Obtain the design drawings of the bridge 1, and determine the positions of the crane fulcrum 8 and the hoisting elevation positioning point 9 according to the design drawings.

[0072] S02, Determine the first stress-free longitudinal manufacturing alignment, the first stress-free included angle, and the first transverse camber value of each PK cross-section composite beam segment.

[0073] S03, Manufacture the PK cross-section composite beam segment according to the first stress-free longitudinal manufacturing alignment, the first stress-free included angle, and the first transverse camber value.

[0074] S04, Conduct pre-assembly on the manufactured PK cross-section composite beam segment, and obtain the second stress-free longitudinal manufacturing alignment, the second stress-free included angle, and the second transverse camber value of the pre-assembled PK cross-section composite beam segment.

[0075] S05, Judge whether the deviation between the second stress-free longitudinal manufacturing alignment and the first stress-free longitudinal manufacturing alignment is within the first preset range, judge whether the deviation between the second stress-free included angle and the first stress-free included angle is within the second preset range, and judge whether the deviation between the second transverse camber value and the first transverse camber value is within the third preset range.

[0076] S06, When all three conditions that the deviation between the second stress-free longitudinal manufacturing alignment and the first stress-free longitudinal manufacturing alignment is within the first preset range, the deviation between the second stress-free included angle and the first stress-free included angle is within the second preset range, and the deviation between the second transverse camber value and the first transverse camber value is within the third preset range are satisfied, it is determined that the PK cross-section composite beam segment meets the manufacturing accuracy conditions.

[0077] In one embodiment, as a further preference, as Figure 4 shown, the manufacturing of the PK cross-section composite beam segment is carried out in batches, and the pre-assembly is carried out in batches, specifically including the following steps:

[0078] S031, Manufacture the jig 10 suitable for the assembly of the PK cross-section composite beam segment, and establish the local coordinate system for the assembly of the PK cross-section composite beam segment; wherein, the coordinate direction of the local coordinate system is consistent with the coordinate direction of the bridge 1.

[0079] S032. Manufacture the first M PK sectional composite beam segments. Taking the center of the first PK sectional composite beam segment at the pylon of Bridge 1 as the zero point, calculate the three-dimensional relative coordinates between adjacent PK sectional composite beam segments. Use the jig 10 to pre-assemble the first M PK sectional composite beam segments to obtain the pre-assembled PK sectional composite beam segments, where M is greater than or equal to 1.

[0080] S033. Compare the height of the hoisting elevation positioning point 9 of the pre-assembled PK sectional composite beam segment with the theoretical positioning elevation. After determining that the error is within the range of ±10 mm, cut the welding bevels at the bolt connection gusset plate holes and welding positions of the pre-assembled PK sectional composite beam segment; otherwise, perform it after error correction.

[0081] S034. Remove the first M - 1 PK sectional composite beam segments. Taking the Mth PK sectional composite beam segment as the reference, manufacture and pre-assemble the second batch of PK sectional composite beam segments, and repeat steps S032 to S033 until all PK sectional composite beam segments are manufactured.

[0082] It should be noted that since the longitudinal alignment gradually increases from the support position to the mid-span position, while the stress loads on the cross beam 41 are basically the same, the first transverse pre-camber values at each position are basically the same. To ensure the smooth connection of the longitudinal alignment at the center position of the main girder, the transverse alignment of the PK sectional composite beam segment should be locally corrected and transitioned from the support to the mid-span direction.

[0083] For the simplified calculation process of the above embodiments, a longitudinal alignment calculation model can be established in advance. The longitudinal alignment calculation model can obtain the longitudinal alignment change of Bridge 1 based on the structural stress change of Bridge 1. The above first stress-free longitudinal manufacturing alignment and first stress-free included angle are specifically obtained through the following steps:

[0084] S011a. Obtain the design elevation and design construction process of the hoisting elevation positioning point 9 according to the design construction process of the design drawing, and calculate the design value of the structural stress of Bridge 1 by calculating the structural stress change in the design construction process.

[0085] S012a. Obtain the on-site conditions, adjust the design construction process according to the on-site conditions to obtain multiple process construction processes, and calculate multiple process values of the structural stress of Bridge 1 by calculating the structural stress change of the multiple process construction processes; where the on-site conditions refer to various condition parameters measured on the construction site, including parameters such as the concrete materials of the pylon and bridge deck, the elastic models and unit weights of the stay cables 2 and steel.

[0086] S013a. Compare the multiple process values with the design value respectively, select the process value closest to the design value as the final value, and use the process construction process corresponding to the final value as the final construction process.

[0087] S014a. Obtain the final camber value and construction camber value of the completed bridge through the longitudinal alignment calculation model according to the final construction process. Obtain the first stress-free longitudinal manufacturing alignment based on the design elevation, the final camber value of the completed bridge, and the construction camber value, and then determine the first stress-free included angle through the first stress-free longitudinal manufacturing alignment. The first stress-free included angle is the included angle between adjacent PK-section composite beam segments in a stress-free state and can be directly obtained through simple calculations based on the first stress-free longitudinal manufacturing alignment.

[0088] The final camber value of the completed bridge refers to the reverse camber value considering the 10-year shrinkage and creep of concrete and the deformation value under the action of vehicle and pedestrian loads. Among them, the camber value due to shrinkage and creep can only be eliminated after 10 years, and the camber value under vehicle and pedestrian loads always exists to offset the deformation during vehicle driving. The construction camber value is the reverse camber value of the main beam deformation from the cantilever construction stage to the completed bridge stage. The final camber value of the completed bridge and the construction camber value can be calculated through a calculation simulation model.

[0089] Furthermore, the first transverse camber value is specifically obtained through the following steps:

[0090] S011b. Take the cross beam 41 as the object alone and pre-establish a cross beam calculation model representing the force and deformation relationship of the cross beam 41; among them, the PK-section composite beam segment includes the cross beam 41.

[0091] S012b. Obtain the deformation value of the cross beam 41 after the lamination process according to the structural force during the process construction process and the cross beam calculation model.

[0092] S013b. Determine the reverse camber value according to the deformation value and use the reverse camber value as the first transverse camber value.

[0093] It should be noted that the establishment process of the longitudinal alignment calculation model and the cross beam calculation model in this embodiment belongs to the prior art. To simplify the method steps, it is not convenient to elaborate too much in the present invention.

[0094] As Figure 5 shown, in one embodiment, it also includes controlling the alignment during the transportation process of the PK-section composite beam segment, specifically the following steps:

[0095] Fix the steel section 12 at the top plate 44 of each PK section composite beam section respectively, set up temporary supports 11 at the positions of the anchor points and hoisting points, and then transport the PK section composite beam section to the construction site; wherein, the PK section composite beam section includes a top plate 44, and anchor points and hoisting points are arranged on the top plate 44. The reinforcement of the steel section 12 ensures that the PK section composite beam section does not undergo local torsion or deformation during transportation or rotation, and the temporary support 11 ensures stable support during transportation or rotation, ultimately ensuring that the alignment of the PK section composite beam section remains unchanged.

[0096] In one embodiment, it further includes the process of longitudinally controlling the alignment of the hoisted PK section composite beam section. The method steps of this embodiment should be completed before the wet joint construction stage of the (N - 2)-th PK section composite beam section 6, wherein the wet joint construction stage of the (N - 2)-th PK section composite beam section 6 is one of the asynchronous construction stages of the bridge 1. The specific steps are as follows:

[0097] S5, use a level instrument to measure the hoisting elevation positioning points 9 of the (N - 2)-th PK section composite beam section, the (N - 1)-th PK section composite beam section, and the N-th PK section composite beam section 4 in sequence to obtain the measured elevations of the three PK section composite beam sections; wherein, N is greater than or equal to 2. Note that the measurement in this step should be carried out when the temperature is stable at night, and there should be no extra temporary loads on the bridge deck during the test.

[0098] S6, compare the measured elevations with the theoretical positioning elevations of the corresponding PK section composite beam sections respectively to obtain the first error value of the (N - 2)-th PK section composite beam section, the second error value of the (N - 1)-th PK section composite beam section, and the third error value of the N-th PK section composite beam section 4. If the first error value, the second error value, and the third error value are all within the range of ±20 mm, the longitudinal alignment control is completed; if the first error value, the second error value, and the third error value do not all satisfy being within the range of ±20 mm, then enter step S7.

[0099] S7, take the PK section composite beam section with the error value outside the range of ±20 mm as the object for cable length adjustment, take the direction from the (N - 2)-th PK section composite beam section to the N-th PK section composite beam section 4 as the cable length adjustment sequence, adjust the cable lengths of the corresponding stay cables 2 of the PK section composite beam sections in sequence, and return to step S6 until the three error values are all within the range of ±20 mm, and the longitudinal alignment control is completed. The N-th PK section composite beam section 4 represents the PK section composite beam section currently undergoing hoisting operation. For safety considerations, the cable force change corresponding to the unit cable length change of the stay cable 2 of the N-th PK section composite beam section 4 should also be calculated synchronously to ensure that the cable force fluctuation is within the allowable range.

[0100] The reason why the above method steps should be completed before the wet joint construction stage of the 6th combined beam segment of the PK section at the (N - 2)th segment is that the 6th combined beam segment of the PK section at the (N - 2)th segment is not superimposed and has a small stiffness, so the cable force required to adjust the change of the hoisting elevation positioning point 9 is small. During the process of adjusting the hoisting elevation positioning point 9, the increased or decreased cable force can be adjusted back during the construction stage of the 6th combined beam segment of the PK section at the (N - 2)th segment. At this time, since the structure has formed as a whole and the bridge deck and the steel beam have been superimposed, the overall stiffness is large, and the local cable force adjustment has little impact on the linearity.

[0101] For the convenience of technicians' understanding, please refer to Figures 1 to 3 , the asynchronous construction process of the cable-stayed bridge with combined beam segments of the PK section starts from the 1st combined beam segment of the PK section at the pylon, and symmetrically constructs in two directions, front and back of the pylon. When hoisting the 4th combined beam segment of the PK section at the Nth segment, the bridge decks above the 5th combined beam segment of the PK section at the (N - 1)th segment and the 6th combined beam segment of the PK section at the (N - 2)th segment are not superimposed, and the remaining hoisted combined beam segments of the PK section are the 7th combined beam segments of the PK section with the bridge decks superimposed. After the 4th combined beam segment of the PK section at the Nth segment is hoisted, the bridge deck of the 6th combined beam segment of the PK section at the (N - 2)th segment is then superimposed.

[0102] In one embodiment, the following steps are further included:

[0103] S81, Obtain the design temperature, collect weather information, and formulate a closure plan. Since the stay cable 2 becomes longer and the overall elevation is lower when the temperature rises, and the stay cable 2 becomes shorter and the elevation is higher when the temperature is lower, the closure of the side span and the middle span is selected to be carried out on a cloudy day or at night when the temperature is equal to the design temperature.

[0104] S82, Calculate the cable force of the bridge 1 to obtain the theoretical value.

[0105] S83, Measure the cable force of the bridge 1 on-site to obtain the measured value, and calculate the deviation value between the measured value and the theoretical value.

[0106] S84, When the deviation value is outside the range of ±5%, it is determined that the cable force is non-compliant. Adjust the cable force by adjusting the cable length, and return to step S82. For example, when the deviation value is greater than 5%, it means that the cable force is too large, and it is necessary to increase the cable length of the stay cable 2 corresponding to the deviation value greater than 5% to reduce the cable force, and return to step S82 to re-measure the cable force.

[0107] S85, When the deviation value is within the range of ±5%, it is determined that the cable force is compliant, and the side span and the middle span are closed.

[0108] Combined with the above embodiments, in the manufacturing process of the present invention, through pre-assembly and batch manufacturing, the manufacturing accuracy is precisely controlled to ensure the accurate alignment during the manufacturing of the PK section composite girder segment; during transportation, the PK section composite girder segment is reinforced and cushioned to prevent deformation; during hoisting, the transverse alignment of the PK section composite girder segment to be hoisted and the already hoisted PK section composite girder segment is ensured to be consistent by means of back jacking; during subsequent construction, the hoisting elevation positioning point 9 is continuously measured. Even if the hoisting elevation positioning point 9 shifts due to the change in the stiffness of the bridge 1, the longitudinal alignment can be adjusted by tensioning the stay cables 2. The present invention comprehensively controls the alignment of the bridge 1 from four dimensions: the manufacturing process, transportation process, hoisting process, and subsequent construction process of the PK section composite girder segment, which can significantly improve the alignment accuracy during the asynchronous construction process and ensure the safety of the bridge 1.

[0109] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge, characterized in that: The steps include: S1, construct the i-th PK section composite beam segment at the cable tower and assemble the bridge crane; where i≥1, i is a positive integer, and the initial value of i is 1; S2, obtaining the theoretical positioning elevation of the hoisting elevation positioning point of the i+1 PK section composite beam segment, using a bridge crane to hoist the i+1 PK section composite beam segment, and after hoisting and positioning the i+1 PK section composite beam segment according to the theoretical positioning elevation, temporarily fixing the i+1 PK section composite beam segment; S3, obtaining the deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane, and lifting the i+1-th PK section composite beam segment to a position matching the deformation area by means of reverse lifting, so that the transverse linear shape of the i+1-th PK section composite beam segment matches the transverse linear shape of the i-th PK section composite beam segment, and then permanently fixing the i+1-th PK section composite beam segment to complete the lifting of the i+1-th PK section composite beam segment; S4, determine whether the i+1th PK section composite beam segment is the last PK section composite beam segment, if so, complete the asynchronous construction of the cable-stayed bridge; if not, assign i+1 to i and return to step S2.

2. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 1 is characterized in that: The step S3 specifically comprises the following steps: S31, obtaining a deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane, and fixing a jack on the i-th PK section composite beam segment to apply an external force to an area corresponding to the deformation area in the i+1-th PK section composite beam segment; S32, the jack gradually pushes the i+1 PK section composite beam segment from the side web position of the i PK section composite beam segment toward the middle of the bridge, and then stacks the plate on the pushed area and performs temporary welding and fixation; wherein, the push-up sequence is the side web, bottom plate, middle web and small longitudinal beam, until the transverse linear shape of the i+1 PK section composite beam segment is pushed up to match the deformation area; wherein, the PK section composite beam segment includes the bottom plate, the side web, the middle web and the small longitudinal beam; S33, permanently fixing the i+1th PK section composite beam segment, and completing the hoisting of the i+1th PK section composite beam segment.

3. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 1 is characterized in that: After step S4, The following steps are involved: S5, sequentially measuring the hoisting elevation positioning points of the N-2 PK section composite beam segment, the N-1 PK section composite beam segment, and the N PK section composite beam segment to obtain the measured elevations of the three PK section composite beam segments; wherein N is greater than or equal to 2; S6, comparing the measured elevation with the theoretical positioning elevation of the corresponding PK section composite beam segment to obtain the first error value of the N-2 PK section composite beam segment, the second error value of the N-1 PK section composite beam segment and the third error value of the N PK section composite beam segment. If the first error value, the second error value and the third error value are all within the range of ±20 mm, the longitudinal linear control is completed; if the first error value, the second error value and the third error value do not meet the requirement of being within the range of ±20 mm, the process proceeds to step S7; S7, take the PK section composite beam segment whose error value is outside the range of ±20mm as the cable length adjustment object, take the direction from the N-2th PK section composite beam segment to the Nth PK section composite beam segment as the cable length adjustment order, adjust the cable lengths of the inclined cables corresponding to the PK section composite beam segments in turn, and return to step S6.

4. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 3 is characterized in that: The steps S5 to S7 are completed before the wet joint construction stage of the N-2 PK section composite beam segment, wherein the wet joint construction stage of the N-2 PK section composite beam segment is one of the asynchronous construction stages of the bridge.

5. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 3 is characterized in that: The step S7 further includes the following steps: S81, obtain the design temperature, collect weather information, and formulate a closure plan, where the closure of the side span and the middle span shall be carried out on cloudy days or at night when the temperature is equal to the design temperature; S82, calculate the bridge cable force and obtain the theoretical value; S83, measuring the bridge cable force on site to obtain a measured value, and calculating a deviation between the measured value and a theoretical value; S84, when the deviation value is outside the range of ±5%, it is determined that the cable force is not in compliance with the regulations, the cable force is adjusted by adjusting the cable length, and the process returns to step S82; S85, when the deviation value is within the range of ±5%, it is determined that the cable tension is compliant, and the side span and the middle span are closed.

6. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 1, characterized in that: The step S1 also includes the following steps: S01, obtaining a design drawing of the bridge, and determining the position of the crane fulcrum and the position of the hoisting elevation positioning point according to the design drawing; S02, determining a first stress-free longitudinal manufacturing line shape, a first stress-free angle, and a first transverse pre-camber value of each PK section composite beam segment; S03, manufacturing a PK section composite beam segment according to a first stress-free longitudinal manufacturing line shape, a first stress-free angle and a first transverse pre-camber value.

7. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 6 is characterized in that: The step S03 further includes the following steps: S04, pre-assembling the manufactured PK section composite beam segment, and obtaining a second stress-free longitudinal manufacturing line shape, a second stress-free angle, and a second transverse pre-camber value of the pre-assembled PK section composite beam segment; S05, determining whether a deviation between the second stress-free longitudinal manufacturing linear shape and the first stress-free longitudinal manufacturing linear shape is within a first preset range, determining whether a deviation between the second stress-free angle and the first stress-free angle is within a second preset range, and determining whether a deviation between the second transverse pre-camber value and the first transverse pre-camber value is within a third preset range; S06, when the deviation between the second stress-free longitudinal manufacturing line shape and the first stress-free longitudinal manufacturing line shape is within the first preset range, the deviation between the second stress-free angle and the first stress-free angle is within the second preset range, and the deviation between the second transverse pre-arch value and the first transverse pre-arch value is within the third preset range, it is determined that the PK section composite beam segment meets the manufacturing accuracy conditions.

8. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 7 is characterized in that: The theoretical positioning elevation in step S2 is obtained specifically through the following steps: When the PK section composite beam segment meets the manufacturing accuracy conditions, the weight of the PK section composite beam segment is obtained; the fulcrum reaction force is calculated according to the weight of the PK section composite beam segment and the crane fulcrum position, and the theoretical positioning elevation of the lifting elevation positioning point when the PK section composite beam segment is lifted is determined according to the fulcrum reaction force.

9. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 6, characterized in that: The step S03 specifically includes the following steps: S031, manufacturing a cradle suitable for assembling the PK section composite beam segment, and establishing a local coordinate system for assembling the PK section composite beam segment; wherein the coordinate direction of the local coordinate system is consistent with the coordinate direction of the bridge; S032, manufacturing the first M PK section composite beam segments, taking the center of the first PK section composite beam segment at the cable tower position of the bridge as the zero point, calculating the three-dimensional relative coordinates between adjacent PK section composite beam segments, and using the jig to pre-assemble the first M PK section composite beam segments to obtain the pre-assembled PK section composite beam segments; wherein M is greater than or equal to 1; S033, comparing the height of the hoisting elevation positioning point of the pre-assembled PK section composite beam segment with the theoretical positioning elevation, and after determining that the error is within the range of ±10 mm, performing opening and welding groove cutting on the pre-assembled PK section composite beam segment; S034, transport the first M-1 sections of PK section composite beam segments, and manufacture and pre-assemble the second batch of PK section composite beam segments based on the Mth PK section composite beam segment, and repeat steps S032 to S033 until all PK section composite beam segments are manufactured.

10. The linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge according to claim 8, characterized in that: It also includes linear control of the transportation process of the PK section composite beam segment, which is specifically as follows: The steel sections are fixed at the top plates of each section of the PK section composite beam, and temporary supports are set at the positions of the anchor points and the lifting points, and then the PK section composite beam sections are transported to the construction site; wherein the PK section composite beam sections include a top plate, on which the anchor points and the lifting points are set.

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