Linear control method for asynchronous construction of PK section composite beam cable-stayed bridge

Abstract

The invention relates to the technical field of bridge engineering, in particular to a linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge, which is characterized in that in the manufacturing process, through pre-assembly and batch manufacturing, the manufacturing precision is accurately controlled, and the linear accuracy of a PK section composite beam section during manufacturing is ensured; in the transportation process, the manufacturing of the PK section composite beam section is reinforced, and the PK section composite beam section is prevented from being deformed by the supporting pad; in the hoisting process, it is ensured that the transverse line shape of the PK section composite beam section to be hoisted and the transverse line shape of the hoisted PK section composite beam section are consistent in a reverse jacking mode; in the subsequent construction process, the hoisting elevation positioning point is continuously measured, and even if the hoisting elevation positioning point deviates due to the rigidity change of the bridge, the longitudinal line shape can be adjusted by tensioning the stay cable.

Description

Technical Field

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

[0002] Steel-concrete composite beam cable-stayed bridges have become one of the main bridge types for large-span bridges because they fully utilize the tensile properties of steel and the compressive properties of concrete. As for the PK section, compared with the I-beam or box section, its wind resistance and stability are relatively better due to its unique inverted trapezoidal design.

[0003] At present, there are two main construction methods for PK section composite beam segment cable-stayed bridges: the traditional construction method and the asynchronous construction method. The traditional construction method mainly requires that the PK section composite beam segment needs to be pre-assembled in the factory, and then hoisted as a whole after being transported to the site. However, its heavy transportation and hoisting weight limits its usage scenarios.

[0004] The construction steps of the asynchronous construction method are mainly as follows: hoisting the N# steel beam during cantilever construction, hoisting the N-2# beam section bridge deck, initially tensioning the N# cable-stayed cable, moving the crane forward to the N# beam section, casting the N-2# beam section wet joint and two N-2# cable-stayed cables, and so on to complete the asynchronous construction of the cable-stayed bridge.

[0005] However, when the asynchronous construction method is adopted, since the bridge deck adopts the post-overlapping construction method, the PK section composite beam section is in an open state before overlapping. At this time, the cross-sectional lateral stiffness of the PK section composite beam section is small, and it is easy to deform during transportation or hoisting, thereby affecting the final line shape of the bridge; secondly, due to the influence of the bridge deck crane load and the bridge deck load, during the hoisting process, the hoisted main beam will produce a downward displacement in the lateral direction, and the beam section to be hoisted will not be deformed, and there will be a lateral height difference, which makes it difficult to ensure the consistency of the lateral line shape of each beam section; finally, since the bridge deck and the main beam are constructed asynchronously, the stiffness of the main beam will also change before and after the overlapping of the bridge deck, resulting in changes in the longitudinal line shape of the bridge, which is difficult to effectively control.

[0006] In view of this, it is necessary to propose a linear control method for asynchronous construction of PK section composite beam cable-stayed bridges 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 beam cable-stayed bridge, so as to solve the technical problem that the linear shape of the bridge is difficult to control during the asynchronous construction process in the prior art.

[0008] To achieve the above object, the present invention provides a linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge, comprising the following steps: 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 starting value of i is 1.

[0009] S2, obtaining the theoretical positioning elevation of the hoisting elevation positioning point of the i+1th PK section composite beam segment, using a bridge crane to hoist the i+1th PK section composite beam segment, after hoisting and positioning the i+1th PK section composite beam segment according to the theoretical positioning elevation, temporarily fix the i+1th PK section composite beam segment.

[0010] S3, obtain the deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane, and push the i+1-th PK section composite beam segment to a position matching the deformation area by means of reverse pushing, so that the transverse line shape of the i+1-th PK section composite beam segment matches the transverse line shape of the i-th PK section composite beam segment, and then permanently fix the i+1-th PK section composite beam segment to complete the lifting of the i+1-th PK section composite beam segment.

[0011] 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.

[0012] Furthermore, the step S3 specifically includes the following steps: S31, obtaining the deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane, and fixing the i-th PK section composite beam segment with a jack to apply external force to the area corresponding to the deformation area in the i+1-th PK section composite beam segment.

[0013] S32, the jack gradually pushes the i+1th PK section composite beam segment from the side web position of the i-th PK section composite beam segment toward the middle of the bridge, and then stacks the plates on the pushed-up area and temporarily welds and fixes it; wherein, the pushing-up sequence is the side web, bottom plate, middle web and small longitudinal beam, until the transverse linear shape of the i+1th PK section composite beam segment is pushed up to match the deformed area; wherein, the PK section composite beam segment includes a bottom plate, a side web, a middle web and a small longitudinal beam.

[0014] S33, permanently fixing the i+1th PK section composite beam segment, and completing the hoisting of the i+1th PK section composite beam segment.

[0015] Preferably, the step S4 further includes the following steps: 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 actual measured elevations of the three PK section composite beam segments; wherein N is greater than or equal to 2.

[0016] S6, compare 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 less than ±20mm, the longitudinal linear control is completed; if the first error value, the second error value and the third error value are not all less than ±20mm, enter step S7.

[0017] S7, take the PK section composite beam segment with an error value greater than or equal to ±20mm as the cable length adjustment object, take the direction from the N-2 PK section composite beam segment to the N 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 sequence, and return to step S6.

[0018] Further preferably, 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.

[0019] Further preferably, the step S7 further includes the following steps: S81, obtain the design temperature, collect weather information, and formulate a closure plan. 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.

[0020] S82, calculate the bridge cable force and obtain the theoretical value.

[0021] S83, measuring the bridge cable force on site to obtain a measured value, and calculating a deviation between the measured value and the theoretical value.

[0022] S84, when the deviation value is greater than ±5%, it is determined that the cable tension is not in compliance with the regulations, the cable tension is adjusted by adjusting the cable length, and the process returns to step S82.

[0023] S85, when the deviation value is less than or equal to ±5%, the cable tension is determined to be compliant, and the side span and the middle span are closed.

[0024] Preferably, the step S1 further 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.

[0025] 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.

[0026] 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.

[0027] Further preferably, the step S03 further includes the following steps: S04, pre-assemble the manufactured PK section composite beam segment, and obtain the second stress-free longitudinal manufacturing line shape, the second stress-free angle, and the second transverse pre-camber value of the pre-assembled PK section composite beam segment.

[0028] S05, determine whether 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, determine whether the deviation between the second stress-free angle and the first stress-free angle is within the second preset range, and determine whether the deviation between the second transverse pre-curvature value and the first transverse pre-curvature value is within the third preset range.

[0029] 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.

[0030] Further preferably, the theoretical positioning elevation in step S2 is obtained by 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.

[0031] Further preferably, the step S03 specifically includes the following steps: S031, manufacturing a cradle suitable for assembling PK section composite beam segments, and establishing a local coordinate system for assembling PK section composite beam segments; wherein the coordinate direction of the local coordinate system is consistent with the coordinate direction of the bridge.

[0032] S032, manufacturing the first M PK section composite beam segments, taking the center of the first PK section composite beam segment at the 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 tire frame to pre-assemble the first M PK section composite beam segments to obtain the pre-assembled PK section composite beam segment; wherein M is greater than or equal to 1.

[0033] S033, comparing the height of the hoisting elevation positioning point of the pre-assembled PK section composite beam section with the theoretical positioning elevation, and after determining that the error is less than ±10mm, performing opening and welding groove cutting on the pre-assembled PK section composite beam section.

[0034] 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.

[0035] Further preferably, the method further includes linear control of the transportation process of the PK section composite beam segment, which is specifically performed in the following steps: 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.

[0036] Compared with the prior art, the present invention has the following beneficial effects: After the hoisting of the PK section composite beam segment is completed, the stiffness of the PK section composite beam segment will be enhanced. Due to the large load on the hoisted PK section composite beam segment caused by factors such as the bridge deck crane, the hoisted PK section composite beam segment is deformed in the lateral direction. The present invention makes the lateral line shape of the rear hoisted PK section composite beam segment match the lateral line shape of the front PK section composite beam segment through the reverse top method, thereby ensuring that the lateral line shape of each PK section composite beam segment is consistent, and the overall lateral line shape of the bridge is controlled under cyclic construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0038] Figure 1 It is a schematic diagram of the overall structure of a bridge during the hoisting operation of a PK section composite beam segment in one embodiment of the present invention; Figure 2 It is a schematic diagram of a local structure of a bridge during the hoisting operation of a PK section composite beam segment in one embodiment of the present invention; Figure 3 It is a schematic top view of a bridge during the hoisting operation of a PK section composite beam segment in one embodiment of the present invention; Figure 4 It is a front view of the overall structure of a PK section composite beam segment during pre-assembly of the PK section composite beam segment in one embodiment of the present invention; Figure 5 A top view of the overall structure of a PK section composite beam segment during pre-assembly of the PK section composite beam segment in one embodiment of the present invention; Figure 6 The present invention is a flowchart of a method for controlling the transverse linear shape of a PK section composite beam segment in one embodiment of the present invention.

[0039] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0040] Description of Figure Numbers: 1. Bridge; 2. Cable-stayed cable; 3. Bridge crane; 4. Nth PK section composite beam segment; 41. Cross beam; 42. Middle web; 43. Side web; 44. Top plate; 45. Small longitudinal beam; 46. Bottom plate; 5. N-1th PK section composite beam segment; 6. N-2th PK section composite beam segment; 7. PK section composite beam segment with overlapped bridge deck; 8. Crane fulcrum; 9. Lifting elevation positioning point; 10. Crane; 11. Temporary support; 12. Steel section. DETAILED DESCRIPTION

[0041] 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.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as described in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] See also Figures 1 to 6 This embodiment provides a linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge. This embodiment mainly controls the transverse linear shape of the bridge 1, including the following steps: S1, construct the i-th PK section composite beam segment at the cable tower and assemble the bridge deck crane 3; where i≥1, i is a positive integer, and the initial value of i is 1.

[0046] S2, obtain the theoretical positioning elevation of the hoisting elevation positioning point 9 of the i+1 PK section composite beam segment, use the bridge crane 3 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 fix the i+1 PK section composite beam segment. The hoisting and positioning should be carried out at night when the temperature is stable. After the hoisting and positioning is completed, the two sides of the PK section composite beam segment are temporarily fixed by nailing or welding. The error between the actual height of the hoisting elevation positioning point 9 and the theoretical positioning elevation during the hoisting and positioning should be controlled within ±10mm.

[0047] The process of obtaining the theoretical positioning elevation is to obtain the weight of the PK section composite beam section when the PK section composite beam section meets the manufacturing accuracy conditions; calculate the fulcrum reaction force according to the weight of the PK section composite beam section and the position of the crane fulcrum 8, and determine the theoretical positioning elevation of the hoisting elevation positioning point 9 when the PK section composite beam section is hoisted according to the fulcrum reaction force. The calculation process of the fulcrum reaction force in this embodiment belongs to the prior art and will not be described in detail here.

[0048] S3, obtain the deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane 3, and push the i+1-th PK section composite beam segment to a position matching the deformation area by means of reverse pushing, so that the transverse line shape of the i+1-th PK section composite beam segment matches the transverse line shape of the i-th PK section composite beam segment, and then permanently fix the i+1-th PK section composite beam segment to complete the lifting of the i+1-th PK section composite beam segment; wherein i is greater than or equal to 1, and i is a positive integer.

[0049] Specifically, S31, obtain the deformation area of ​​the i-th PK section composite beam segment after assembling the bridge deck crane 3, and use a jack fixed on the i-th PK section composite beam segment to apply external force to the area in the i+1-th PK section composite beam segment corresponding to the deformation area.

[0050] S32, the jack gradually pushes the i+1 PK section composite beam segment from the position of the side web 43 of the i PK section composite beam segment toward the middle of the bridge 1, and then the pushed area is stacked and temporarily welded and fixed; wherein, the pushing sequence is the side web 43, the bottom plate 46, the middle web 42 and the small longitudinal beam 45, until the transverse linear shape of the i+1 PK section composite beam segment is pushed to match the deformation area, for example, the height of the top surface of the side web 43 of the i+1 PK section composite beam segment is flush with the height of the top surface of the side web 43 in the deformation area of ​​the i PK section composite beam segment; wherein, the PK section composite beam segment includes the bottom plate 46, the cross beam 41, the side web 43, the middle web 42 and the small longitudinal beam 45, such as Figure 4 and Figure 5 As shown, the bottom plate 46 is arranged at the bottom of the PK section composite beam segment, the side webs 43 are arranged on both sides of the bottom plate 46, the small longitudinal beam 45 is located in the center of the PK section composite beam segment, the middle web 42 is arranged between the small longitudinal beam 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, the cross beam 41 is fixed to 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 webs 43, the middle webs 42 and the small longitudinal beam 45 in sequence. The yard plate is a steel plate placed in the reversed top area to connect the i-th PK section composite beam segment and the i+1-th PK section composite beam segment.

[0051] S33, permanently fixing the i+1th PK section composite beam segment, and completing the hoisting of the i+1th PK section composite beam segment.

[0052] 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.

[0053] In one embodiment, the manufacturing process of the PK section composite beam segment is also included, and the linear shape of the manufactured PK section composite beam segment is controlled. The specific process is as follows: S01, obtaining the design drawings of the bridge 1, and determining the position of the crane fulcrum 8 and the position of the hoisting elevation positioning point 9 according to the design drawings.

[0054] 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.

[0055] 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.

[0056] S04, pre-assemble the manufactured PK section composite beam segment, and obtain the second stress-free longitudinal manufacturing line shape, the second stress-free angle, and the second transverse pre-camber value of the pre-assembled PK section composite beam segment.

[0057] S05, determine whether 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, determine whether the deviation between the second stress-free angle and the first stress-free angle is within the second preset range, and determine whether the deviation between the second transverse pre-curvature value and the first transverse pre-curvature value is within the third preset range.

[0058] 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.

[0059] In one embodiment, as further preferred, Figure 4 As shown, the manufacturing of the PK section composite beam segment is carried out in batches, and the pre-assembly is carried out in batches, which specifically includes the following steps: S031, manufacturing a tire frame 10 suitable for assembling PK section composite beam segments, and establishing a local coordinate system for assembling PK section composite beam segments; wherein the coordinate direction of the local coordinate system is consistent with the coordinate direction of the bridge 1.

[0060] S032, manufacture the first M PK section composite beam segments, take the center of the first PK section composite beam segment at the tower of bridge 1 as the zero point, calculate the three-dimensional relative coordinates between adjacent PK section composite beam segments, use the tire frame 10 to pre-assemble the first M PK section composite beam segments, and obtain the pre-assembled PK section composite beam segments; wherein M is greater than or equal to 1.

[0061] S033, compare the height of the lifting elevation positioning point 9 of the pre-assembled PK section composite beam segment with the theoretical positioning elevation, and after determining that the error is less than ±10mm, perform the node plate opening for bolt connection and the welding groove cutting at the welding position of the pre-assembled PK section composite beam segment, otherwise proceed after the error correction.

[0062] 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.

[0063] It should be noted that since the longitudinal line shape gradually increases from the support position to the mid-span position, and the force load on the beam 41 is basically the same, the first transverse pre-camber value is basically the same at each position. In order to ensure that the longitudinal line shape is smoothly connected at the center of the main beam, the transverse line shape of the PK section composite beam section should be locally corrected and transitioned from the support to the mid-span direction.

[0064] In order to simplify the calculation process of the above embodiment, a longitudinal linear shape calculation model can be established in advance, and the longitudinal linear shape calculation model can obtain the longitudinal linear shape change of the bridge 1 according to the structural stress change of the bridge 1. The above first stress-free longitudinal manufacturing linear shape and the first stress-free angle are obtained specifically through the following steps: S011a, obtaining 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 calculating the structural stress change in the design construction process to obtain the design value of the structural stress of the bridge 1.

[0065] S012a, obtaining site conditions, adjusting the design construction process according to the site conditions, obtaining multiple process construction processes, and calculating the structural stress changes of the multiple process construction processes to obtain multiple process values ​​of the structural stress of the bridge 1; wherein the site conditions refer to various condition parameters measured at the construction site, including parameters such as the elastic model and bulk density of the cable tower and bridge deck concrete materials, the inclined cable 2 and the steel.

[0066] S013a, comparing the multiple process values ​​with the design value respectively, selecting the process value closest to the design value as the final value, and taking the process construction procedure corresponding to the final value as the final construction procedure.

[0067] S014a, according to the final construction process, the bridge pre-camber value and the construction pre-camber value are obtained through the longitudinal line shape calculation model, the first stress-free longitudinal manufacturing line shape is obtained according to the design elevation, the bridge pre-camber value and the construction pre-camber value, and the first stress-free angle is determined through the first stress-free longitudinal manufacturing line shape. The first stress-free angle is the angle between two adjacent PK section composite beam sections in a state without external stress, and can be directly obtained through simple calculation according to the first stress-free longitudinal manufacturing line shape.

[0068] The pre-camber value of the completed bridge refers to the inverse camber value of the deformation value under the 10-year shrinkage creep of concrete and the load of cars and people, among which the pre-camber value of shrinkage creep needs to wait until 10 years to be eliminated, and the pre-camber value under the load of cars and people always exists to offset the deformation during vehicle driving. The construction pre-camber value is the inverse camber value of the deformation of the main beam from the cantilever construction to the bridge completion stage. The pre-camber value of the completed bridge and the construction pre-camber value can be calculated according to the calculation simulation model.

[0069] Furthermore, the first transverse pre-camber value is obtained by the following steps: S011b, taking the crossbeam 41 as an object, a crossbeam calculation model representing the relationship between the force and deformation of the crossbeam 41 is pre-established; wherein the PK section composite beam segment includes the crossbeam 41.

[0070] S012b, obtaining the deformation value of the beam 41 after the overlapping process according to the structural stress of the construction process and the beam calculation model.

[0071] S013b: Determine a reverse arch value according to the deformation value, and use the reverse arch value as the first transverse pre-arch value.

[0072] It is worth noting that the process of establishing the longitudinal linear calculation model and the beam calculation model described in this embodiment belongs to the prior art. In order to simplify the method steps, it is not convenient to make too many details in the present invention.

[0073] like Figure 5 As shown, in one embodiment, it also includes linear control of the transportation process of the PK section composite beam segment, which is specifically the following steps: The steel sections 12 are fixed at the top plates 44 of each section of the PK section composite beam, and temporary pads 11 are set at the anchor points and the lifting points, and then the PK section composite beam section is transported to the construction site; wherein the PK section composite beam section includes a top plate 44, and the top plate 44 is provided with anchor points and lifting points. The steel sections 12 are reinforced to ensure that the PK section composite beam section does not undergo local twisting or deformation during transportation or transfer, and the temporary pads 11 ensure that the support is stable during transportation or transfer, and finally ensure that the linear shape of the PK section composite beam section remains unchanged.

[0074] In one embodiment, it also includes a longitudinal linear control process for the hoisted PK section composite beam segment, and the method steps described in this embodiment should be completed before the wet joint construction stage of the N-2 section PK section composite beam segment 6, wherein the wet joint construction stage of the N-2 section PK section composite beam segment 6 is one of the asynchronous construction stages of the bridge 1. Specifically, it includes the following steps: S5, using a leveling instrument, sequentially measure the hoisting elevation positioning point 9 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 4 to obtain the measured elevations of the three PK section composite beam segments; wherein N is greater than or equal to 2. Note that the measurement described in this step should be performed at night when the temperature is stable, and there should be no extra temporary load on the bridge deck during the test.

[0075] S6, compare 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 4. If the first error value, the second error value and the third error value are all less than ±20mm, the longitudinal linear control is completed; if the first error value, the second error value and the third error value are not less than ±20mm, enter step S7.

[0076] S7, take the PK section composite beam segment with an error value greater than or equal to ±20mm as the cable length adjustment object, take the direction from the N-2 PK section composite beam segment to the N PK section composite beam segment 4 as the cable length adjustment order, adjust the cable length of the inclined cable 2 corresponding to the PK section composite beam segment in sequence, and return to step S6 until the three error values ​​are all less than ±20mm to complete the longitudinal linear control. The N PK section composite beam segment 4 represents the PK section composite beam segment currently undergoing hoisting operations. For safety reasons, the cable force change corresponding to the unit cable length change of the inclined cable 2 of the N PK section composite beam segment 4 should also be calculated synchronously to ensure that the cable force fluctuation is within the allowable range.

[0077] The reason why the above method and steps should be completed before the wet joint construction stage of the N-2 PK section composite beam segment 6 is that the N-2 PK section composite beam segment 6 is not overlapped, the rigidity is small, and the cable force required to adjust the change of the hoisting elevation positioning point 9 is small. The cable force increased or decreased in the process of adjusting the hoisting elevation positioning point 9 can be adjusted back during the construction stage of the N-2 PK section composite beam segment 6. At this time, since the structure has been formed as a whole, and the bridge deck and the steel beam have been overlapped, the overall rigidity is large, and the local cable force adjustment has little effect on the line shape.

[0078] For technical personnel to understand, please refer to Figures 1 to 3The asynchronous construction process of the PK section composite beam cable-stayed bridge is to start with the first section of the PK section composite beam at the cable tower, and to construct symmetrically in the two directions in front and behind the cable tower. When the Nth PK section composite beam segment 4 is hoisted, the bridge deck above the N-1th PK section composite beam segment 5 and the N-2th PK section composite beam segment 6 is not overlapped, and the remaining hoisted PK section composite beam segments are the PK section composite beam segments 7 with overlapped bridge decks. After the Nth PK section composite beam segment 4 is hoisted, the bridge deck of the N-2th PK section composite beam segment 6 is overlapped.

[0079] In one embodiment, the following steps are also included: S81, obtain the design temperature, collect weather information, and formulate a closure plan. As the temperature rises, the cable 2 becomes longer, the overall elevation is low, and the temperature is low, the cable 2 becomes shorter, and the elevation is high. Therefore, the closure of the side span and the middle span is carried out on cloudy days or at night when the temperature is equal to the design temperature.

[0080] S82, calculate the cable force of bridge 1 and obtain a theoretical value.

[0081] S83, measuring the cable force of the bridge 1 on site to obtain a measured value, and calculating the deviation between the measured value and the theoretical value.

[0082] S84, when the deviation value is greater than ±5%, it is determined that the cable force is not in compliance, the cable force is adjusted by adjusting the cable length, and the process returns to step S82. For example, when the deviation value is greater than 5%, it means that the cable force is too large, and the cable force needs to be reduced by increasing the cable length of the inclined cable 2 corresponding to the deviation value greater than 5%, and the process returns to step S82 to re-measure the cable force.

[0083] S85, when the deviation value is less than or equal to ±5%, the cable tension is determined to be compliant, and the side span and the middle span are closed.

[0084] In combination with the above embodiments, the present invention controls the manufacturing accuracy precisely during the manufacturing process by pre-assembling and manufacturing in batches, ensuring the accuracy of the linear shape of the PK section composite beam segment during manufacturing; during transportation, the PK section composite beam segment is reinforced and supported to prevent deformation of the PK section composite beam segment; during the hoisting process, the PK section composite beam segment to be hoisted and the hoisted PK section composite beam segment are ensured to be consistent in transverse linear shape by the reverse top method; during the subsequent construction process, the hoisting elevation positioning point 9 is continuously measured, and even if the stiffness change of the bridge 1 causes the hoisting elevation positioning point 9 to shift, the longitudinal linear shape can be adjusted by tensioning the inclined cable 2. The present invention comprehensively controls the linear shape of the bridge 1 from four dimensions: the manufacturing process, transportation process, hoisting process and subsequent construction process of the PK section composite beam segment, which can significantly improve the linear accuracy during the asynchronous construction process and ensure the safety of the bridge 1.

[0085] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also 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 less than ±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 less than ±20 mm, the process proceeds to step S7; S7, take the PK section composite beam segment with an error value greater than or equal to ±20mm as the cable length adjustment object, take the direction from the N-2 PK section composite beam segment to the N 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 sequence, 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 greater than ±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 less than or equal to ±5%, the cable tension is determined to be 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 less than ±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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