Construction control method for steel shell and concrete combined cable tower

Abstract

The application relates to the technical field of construction, in particular to a construction control method for a steel shell and a concrete combined cable tower. n Segment and T n+1 Segment surface sketch reference line and mark matching point; to T n Segment and T n+1 Segment are matched and aligned once; after the T n Segment and T n+1 Segment are fine-tuned, and secondary matching and alignment are completed; the T n Segment and T n+1 Segment are temporarily fixed by coding; based on a total station, the three-dimensional coordinates of the upper surface measuring points of the T n+1 Segment are measured, and the mileage direction error Ddx and the offset direction error Ddy are calculated by comparing with the theoretical coordinates; according to the mileage error Ddx, the offset error Ddy, the mileage design allowable error dx and the offset design allowable error dy, a dynamic switching control strategy is executed. The application can effectively eliminate the initial deformation in transportation and hoisting, consider the construction precision and efficiency, inhibit error accumulation and guarantee the linear quality of the high-level cable tower.

Description

Technical Field

[0001] This invention relates to the field of construction technology, and in particular to a construction control method for a steel-shell and concrete composite cable tower. Background Technology

[0002] As a key load-bearing structure supporting the main cable or stay cables in a cable-stayed or suspension bridge, the tower is usually composed of a tower base, tower column, crossbeam and tower crown. Its construction accuracy is directly related to the overall stress performance, alignment control and long-term service safety of the bridge.

[0003] In recent years, steel-concrete composite cable towers have been widely used in long-span bridge projects due to their excellent mechanical properties, ease of construction, and durability. Currently, the industry mainly adopts two types of alignment control strategies: single-segment control and multi-segment control. The single-segment control method ensures that each segment meets the design alignment requirements after installation by hoisting, measuring, and adjusting it segment by segment. While it effectively controls local errors, its cumbersome construction process, high matching difficulty, and long operation cycle severely restrict overall construction efficiency. The multi-segment control method relies on high-precision matching relationships preset during the manufacturing stage. Under the premise of controllable transportation and manufacturing errors, it allows for the continuous hoisting and docking of multiple segments, significantly improving construction speed and simplifying on-site operations. However, this method cannot avoid the systematic errors caused by the accumulation of small deviations segment by segment. Especially in the construction of high-rise cable towers, once the accumulated error exceeds the allowable range of the specifications, it may threaten structural safety.

[0004] However, both of these methods have obvious limitations and cannot meet the dual requirements of construction accuracy and efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a construction control method for steel-shell and concrete composite cable towers, in order to solve the technical problem that it is difficult to simultaneously achieve single-segment control and multi-segment control in the construction of existing steel-shell and concrete composite cable towers.

[0006] This invention provides a construction control method for a composite steel-shell and concrete cable tower, comprising at least: Step 1. In T n Segment and T n+1 After the segments are transported to the construction site, at T n Segment and T n+1 The reference lines are engraved on the surface of the segment and the matching points are marked, and the matching parts are welded at the matching points; Step 2. For T n Segment and T n+1 The segments were trial-lifted, and the actual distances between the baselines and the actual distances between the mating parts were measured to complete one matching and alignment. Step 3. Align T after one matchn Segment and T n+1 After segmental fine-tuning to ensure that the measured distance is within the allowable error threshold on site, secondary matching and alignment are completed based on the jack; Step 4. For T n Segment and T n+1 Segments are temporarily fixed by coding; Step 5. Using a total station, measure T n+1 The three-dimensional coordinates of 10 measuring points on the upper surface of the segment are compared with the theoretical coordinates to calculate the mileage direction error Δdx and the offset direction error Δdy. Step 6. Based on the mileage error Δdx, offset error Δdy, mileage design tolerance error dx, and offset design tolerance error dy, execute a dynamic switching control strategy. The dynamic switching control strategy is as follows: If Δdx > dx or Δdy > dy, enter single-segment control for T. n+1 After the segments are finely adjusted and re-measured, and the error is confirmed to be within the standard, subsequent work is carried out. If the current segment satisfies Δdx ≤ dx and Δdy ≤ dy, and the historical cumulative plane error satisfies ΣΔdx i ≤dx and ΣΔdy i ≤ dy, enter multi-segment control, keep the field matching geometry unchanged, directly confirm the position and complete the subsequent procedures; When the cumulative elevation deviation ΣΔhi>h, at T n+j A dedicated adjustment segment is set within the segment, where h represents the design tolerance.

[0007] In some embodiments, the T n Segment and T n+1 After the segments are transported to the construction site, at T n Segment and T n+1 The process includes marking reference lines and matching points on the segment surfaces, and welding matching parts at the matching points. This includes at least setting reference lines at a fixed height H from the upper and lower surfaces of each segment's steel shell, with the reference lines being at least L. nt L nd L n+1 t and L n+1d Where t represents the upper surface and d represents the lower surface; H is 200 mm. In some embodiments, the T n Segment and T n+1 Perform trial hoisting of segments, measure the actual distance between baselines and the actual distance between mating parts, and complete one matching alignment, including at least: measuring T n+1 Segment lower surface reference line L n+1d With T n Segment upper surface reference line Lnt The vertical distance l' between the two mating parts and the horizontal distance m' between the centers of the two mating parts, when |l' l|≤Δl and |m' When m|≤Δm, it is determined that the matching and alignment are in place in one go. Here, l and m are the design spacing preset in the manufacturing stage, and Δl and Δm are the on-site allowable error thresholds.

[0008] In some embodiments, the T n Segment and T n+1 The segments are temporarily fixed by marking, including at least the use of temporary marking plates with dimensions of 150mm × 100mm × 20mm, along the T-shaped path. n+1 One segment is arranged every 300mm along the outer circumference of the segment.

[0009] In some embodiments, the 10 measuring points include 6 corner points and 4 side midpoints.

[0010] In some embodiments, the field tolerance threshold Δl is 2 mm, and the field tolerance threshold Δm is 3 mm.

[0011] In some embodiments, the mileage design tolerance error dx and the offset design tolerance error dy are both 10 mm, and the design tolerance error h is 30 mm.

[0012] In some embodiments, the mating part is a perforated steel plate with a hole diameter of 22 mm.

[0013] In some embodiments, the total station has an angle measurement accuracy of not less than 1″, and the coordinates of 10 measuring points are collected repeatedly three times and the average value is taken.

[0014] In some embodiments, the total station performs three coordinate acquisitions at 10 measuring points and takes the average value to determine the final coordinates.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The off-site “1+1” matching system constructed through steps 1 to 3 utilizes the dual geometric constraints of the baseline spacing l’ and the matching part spacing m’ to effectively suppress the initial deformation caused by transportation, hoisting and welding, so that the initial state of segment docking is close to the ideal design configuration; 2. By using a total station to measure control points, real spatial pose data is obtained, providing reliable input for error judgment; 3. Through a dynamic switching mechanism, based on whether a single segment exceeds tolerance and the trend of cumulative error, it automatically selects single-segment control or multi-segment control, avoiding the one-size-fits-all control mode in traditional methods; in the multi-segment control stage, the matching relationship preset in the manufacturing stage is retained, reducing on-site adjustment procedures and shortening the installation cycle; in the single-segment control stage, millimeter-level positioning is used to prevent error transmission. 4. By monitoring ΣΔhi and inserting dedicated adjustment segments when necessary, the long-term elevation drift problem is solved, ensuring that the overall verticality of the tower meets the requirements of relevant standards such as the "Technical Specification for Construction of Highway Bridges and Culverts" (JTG / T 3650).

[0016] 5. This invention is applicable to steel-shell and concrete composite cable tower projects with a height exceeding 200 meters, and is especially suitable for the construction of main towers of long-span cable-stayed bridges or suspension bridges. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the construction control method for the steel shell and concrete composite cable tower of the present invention; Figure 2 This is a schematic diagram of the distribution of measuring points on the upper surface of Tn+1 according to the present invention; Figure 3 This is a schematic diagram of the construction control method of the present invention; Figure 4 This is a schematic diagram of error control using the single-segment control method and the multi-segment control method of the present invention. Detailed Implementation

[0019] The following will be based on embodiments of the present invention. Figures 1-4 The technical solutions in the embodiments of the present invention will be clearly and completely described together. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Partial interpretation: 1. Steel-concrete composite cable tower: This is a synergistic load-bearing structure formed by inner and outer double-layer reinforced steel shells and internal concrete filling. It combines the advantages of both steel and concrete structures and has become an important development direction for modern long-span bridge construction. 2. The "1+1" matching system: This is a process used in bridge tower construction to ensure the accuracy of segment connection. It primarily involves pre-assembling tower segments on a ground-based formwork. By simulating the actual installation process, the geometric dimensions, alignment, and interface fit of the segments are checked in advance, providing a benchmark for subsequent high-altitude installation. Through "1+1" (i.e., two segments combined) vertical matching, the spatial relationship between segments is verified, including the vertical connection elevation, axial deviation, and interface tightness, ensuring that the welded or bolted connections meet design requirements.

[0021] Example This embodiment provides a construction control method for a steel-shell and concrete composite cable tower, comprising at least the following steps: Step 1. After the Tn and Tn+1 segments are transported to the construction site, baselines are engraved and matching points are marked on the surfaces of the Tn and Tn+1 segments, and matching parts are welded at the matching points; Step 2. The Tn and Tn+1 segments are trial-lifted, and the measured distance between the baselines and the measured distance between the matching parts are measured to complete the first matching alignment; Step 3. The Tn and Tn+1 segments are fine-tuned after the first matching alignment to ensure that the measured distance is within the allowable error threshold on site, and then a second matching alignment is completed based on jacks; Step 4. The Tn+1 segments are then... Step 5. Using a total station, measure the three-dimensional coordinates of 10 measuring points on the upper surface of segment Tn+1 and compare them with the theoretical coordinates to calculate the mileage direction error Δdx and offset direction error Δdy; Step 6. Based on the mileage error Δdx, offset error Δdy, mileage design allowable error dx, and offset design allowable error dy, execute a dynamic switching control strategy. The dynamic switching control strategy is as follows: if Δdx>dx or Δdy>dy, enter single-segment control, perform fine adjustment and remeasurement on segment Tn+1, and after confirming that the error meets the standard, proceed with subsequent operations; if the current segment meets Δdx... If the cumulative plane error ΣΔdxi ≤ dx and ΣΔdyi ≤ dy, and the cumulative plane error satisfies ΣΔdxi ≤ dx and ΣΔdyi ≤ dy, then enter multi-segment control, maintain the field matching geometric relationship unchanged, directly confirm the positioning and complete the subsequent procedures; when the cumulative elevation deviation ΣΔhi>h, set a dedicated adjustment segment in segment Tn+j, where h is the design allowable error.

[0022] To better understand this invention, the details are as follows: When T n Segment and T n+1 After the segments are transported to the construction site, reference lines are marked at a fixed height H from the upper and lower surfaces of the steel shell. H is preferably 200mm to avoid the heat-affected zone of the weld and to facilitate on-site measurement. At T... n The reference line L is marked on the upper surface of the segment. nt The lower surface is engraved with L nd ; in T n+1L-shaped markings on the upper surface of the segment n+1t The lower surface is engraved with L n+1d Meanwhile, in T n Midpoint of the upper surface of the segment and T n+1 A matching point is set at the midpoint of the lower surface of the segment, and a perforated steel plate is welded at the matching point as a matching part for subsequent bolt connection and alignment adjustment. The matching part is made of Q345B steel plate with a thickness of 20mm and a hole diameter of 22mm to accommodate M20 temporary mounting bolts.

[0023] T n Segment and T n+1 The segments are placed side by side on a special support frame next to the tower. The support frame is equipped with adjustable supports, which can be adjusted according to the curvature of the segments to make the two segments simulate the actual installation tilt angle on the tower.

[0024] Using a gantry crane to T n+1 The segments were test-lifted, first the T n+1 The segment is slowly raised to a height of approximately 30cm above the ground, with the hoisting ropes hanging naturally. It is then left to stand to allow elastic deformation and stress concentration generated during the hoisting process to dissipate. Subsequently, the gantry crane is moved, and the T segment is observed. n+1 Check for any obvious tilting or swaying of the segment, and after confirming that the hoisting system is stable, slowly place it back into the jig.

[0025] Lift T again n+1 Segment, so that its lower surface matching point is with T n The matching points on the upper surface of the segment are aligned at once, and a preliminary connection is made by passing temporary mounting bolts through the holes in the matching parts. At this time, T is measured. n+1 Segment lower surface reference line L n+1d With T n Segment upper surface reference line L nt The vertical distance l' between the two mating parts and the horizontal distance m' between the centers of the two mating parts are specified. The preset standard distances are l=500mm and m=800mm, respectively, with on-site allowable error thresholds Δl=2mm and Δm=3mm. If the measured values ​​satisfy |l' l|≤2mm and|m' If m|≤3mm, it is determined that the matching and alignment are in place in one go; otherwise, the alignment of the matching points needs to be readjusted.

[0026] After the initial alignment is complete, place the hydraulic jack on T. n+1 Below the four corners of the segment, the segment is finely adjusted in three dimensions by a synchronous control system until l' and m' are close to l and m respectively, thus completing the "1+1" fine matching under the field.

[0027] T who completed off-field match n+1 The entire segment was lifted to the installed T. nSlowly lower the segment directly above it to re-align its matching points. Repeat the measurement of l' and m'. If the values ​​exceed the allowable range, use the hydraulic jacks located at the top of the tower to adjust T. n+1 The segments are fine-tuned in both horizontal and vertical directions until |l' is satisfied. l|≤2mm and|m' m|≤3mm.

[0028] After meeting the standard, in T n+1 A temporary mounting plate measuring 150mm × 100mm × 20mm is welded every 300mm along the circumference of the outer wall of the segment. One end of the mounting plate is fully welded to the T. n+1 The outer wall of the segment, the other end of which is welded to T n The top edge of the segment forms a temporary rigid connection to prevent segment displacement caused by wind load or construction disturbance.

[0029] Subsequently, using a total station with an angle measurement accuracy of no less than 1″ and a distance measurement accuracy of no less than ±(1mm+1ppm), the T... n+1 Three-dimensional coordinates were acquired from 10 measuring points arranged on the upper surface of the segment, for reference. Figure 2 The control points include six corner points, corresponding to the vertices of the hexagonal or rectangular steel shell cross-section, and four midpoints of the sides. In this embodiment, these are the midpoints of the middle span, the side spans, the outer side, and the inner side. A forced centering base is used during measurement, and each control point is observed three times and the average value is taken to improve data reliability. The measured coordinates are compared with the theoretical coordinates provided by the BIM model or design drawings to calculate the mileage direction error Δdx and the offset direction error Δdy.

[0030] If Δdx > dx or Δdy > dy, where dx = dy = 10mm is the allowable error for the single-segment planar position specified in the design, then single-segment control is initiated: Using the jack at the top of the tower to... n+1 The segments undergo fine-tuning, adjusting their horizontal position and elevation. After adjustment, all 10 control points are re-measured using a total station to confirm Δdx ≤ 10mm and Δdy ≤ 10mm. Subsequently, the uniformity of the circumferential joint gap is checked, requiring ≤2mm, misalignment ≤1mm, and the fit of mating parts, among other pre-welding matching indicators. If all meet the requirements of the "Standard for Acceptance of Construction Quality of Steel Structures" GB50205, formal circumferential joint welding is then carried out. Welding is performed using... Gas shielded welding was performed using ER50-6 welding material, with a weld leg size of not less than 8mm. After welding, all temporary support plates were removed, and the mating parts were permanently connected using high-strength bolts (M20, grade 8.8) or full welding, followed by casting a T-shaped weld. n+1 The segment is constructed using C50 self-compacting concrete. During subsequent construction, the elevation deviation ΣΔhi of each segment is continuously accumulated. When ΣΔhi > h, h = 30 mm, which is the allowable cumulative elevation error specified in the design. (T)n+j A dedicated adjustment segment is set in the segment (j≥2). The height of the steel shell of the dedicated adjustment segment is corrected according to the negative value of ΣΔhi. For example, if ΣΔhi=+25mm, the distance between the upper and lower flange faces is reduced by 25mm when the segment is manufactured, and the internal concrete pouring elevation is adjusted down at the same time to ensure the continuity of the tower column axis and compensate for the cumulative elevation deviation in one go.

[0031] If Δdx ≤ 10mm and Δdy ≤ 10mm, and the historical cumulative plane error satisfies ΣΔdxi ≤ 10mm and ΣΔdyi ≤ 10mm, then proceed to the multi-segment control process: T n+1 The temporary mating parts of the segments are restored to their original relative positions in the vertical mating state at the manufacturer, that is, maintaining the geometric relationship unchanged during the off-site "1+1" mating; the circumferential gap is checked for uniformity, no signs of forced assembly, and no plastic deformation of the mating parts. If these indicators meet the manufacturing acceptance standards, T is directly confirmed. n+1 The segments are positioned without requiring on-site adjustments; subsequent steps include circumferential welding, connection of mating components, and concrete pouring. Subsequent segments T... n+2 T n+3 ...The same matching relationship was used for continuous installation. Only after each segment was installed was the coordinates of the control points on its upper surface recorded using a total station, and the cumulative plane error ΣΔdi was updated. .

[0032] When construction reaches a certain segment T n+j When (j≥2), if ΣΔdi>d, and d=20mm is the cumulative plane error threshold specified in the design, then the multi-segment control should be terminated immediately, and the T should be adjusted accordingly. n+j Segmental single-segment control was used for fine-tuning and retesting; whether the segment subsequently reverted to multi-segment control was determined based on T. n+j The cumulative error after segment adjustment is judged to ensure that ΣΔdxi ≤ 10mm and ΣΔdyi ≤ 10mm again.

[0033] All measurement data, adjustment records, welding parameters, and concrete pouring information of the method in this embodiment are entered into the project BIM management platform to achieve full traceability.

[0034] To better illustrate the present invention, the inventors provide the following examples: The invention was successfully applied in the construction of the main tower (268m high) of a cross-river cable-stayed bridge. Compared with the traditional single-segment control method, it shortened the construction period by about 22%, controlled the cumulative plane error within 18mm, and completely eliminated the elevation deviation through a dedicated adjustment segment, fully verifying the feasibility and superiority of the invention.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0036] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A construction control method for a composite steel-shell and concrete cable-stayed tower, characterized in that, At least including: Step 1. In T n Segment and T n+1 After the segments are transported to the construction site, at T n Segment and T n+1 The reference lines are engraved on the surface of the segment and the matching points are marked, and the matching parts are welded at the matching points; Step 2. For T n Segment and T n+1 The segments were trial-lifted, and the actual distances between the baselines and the actual distances between the mating parts were measured to complete one matching and alignment. Step 3. Align T after one match n Segment and T n+1 After segmental fine-tuning to ensure that the measured distance is within the allowable error threshold on site, secondary matching and alignment are completed based on the jack; Step 4. For T n Segment and T n+1 Segments are temporarily fixed by coding; Step 5. Using a total station, measure T n+1 The three-dimensional coordinates of 10 measuring points on the upper surface of the segment are compared with the theoretical coordinates to calculate the mileage direction error Δdx and the offset direction error Δdy. Step 6. Based on the mileage error Δdx, offset error Δdy, mileage design tolerance error dx, and offset design tolerance error dy, execute a dynamic switching control strategy. The dynamic switching control strategy is as follows: If Δdx > dx or Δdy > dy, enter single-segment control, and apply T... n+1 After the segments are finely adjusted and re-measured, and the error is confirmed to be within the standard, subsequent work is carried out. If the current segment satisfies Δdx ≤ dx and Δdy ≤ dy, and the historical cumulative plane error satisfies ΣΔdx i ≤ dx and ΣΔdy i ≤ dy, enter multi-segment control, keep the field matching geometry unchanged, directly confirm the position and complete the subsequent procedures; When the cumulative elevation deviation ΣΔhi > h, at T n+j A dedicated adjustment segment is set in the segment, where j≥2 and h is the design tolerance.

2. The method according to claim 1, characterized in that, The above in T n Segment and T n+1 After the segments are transported to the construction site, at T n Segment and T n+1 The process includes marking reference lines and matching points on the segment surfaces, and welding matching parts at the matching points. This includes at least setting reference lines at a fixed height H from the upper and lower surfaces of each segment's steel shell, with the reference lines being at least L. nt L nd L n+1t and L n+1d Where t represents the upper surface and d represents the lower surface; H is 200 mm.

3. The method according to claim 2, characterized in that, The T n Segment and T n+1 Perform trial hoisting of segments, measure the actual distance between baselines and the actual distance between mating parts, and complete one matching alignment, including at least: measuring T n+1 Segment lower surface reference line L n+1d With T n Segment upper surface baseline L nt The vertical distance l' between the two mating parts and the horizontal distance m' between the centers of the two mating parts, when |l' l|≤Δl and |m' When m|≤Δm, it is determined that the matching and alignment are in place in one go. Here, l and m are the design spacing preset in the manufacturing stage, and Δl and Δm are the on-site allowable error thresholds.

4. The method according to claim 1, characterized in that, The T n Segment and T n+1 The segments are temporarily fixed by marking, including at least the use of temporary marking plates with dimensions of 150mm × 100mm × 20mm, along the T-shaped path. n+1 One segment is arranged every 300mm along the circumference of the outer wall of the segment.

5. The method according to claim 1, characterized in that, The 10 measuring points include 6 corner points and 4 midpoints of the sides.

6. The method according to claim 3, characterized in that, The on-site allowable error threshold Δl is 2mm, and the on-site allowable error threshold Δm is 3mm.

7. The method according to claim 1, characterized in that, The allowable error for mileage design dx and the allowable error for offset design dy are both 10 mm, and the allowable error for design h is 30 mm.

8. The method according to claim 1, characterized in that, The matching part is a perforated steel plate with a hole diameter of 22mm.

9. The method according to claim 1, characterized in that, The total station's angle measurement accuracy is no less than 1″, and the coordinates of 10 measuring points are collected three times and the average value is taken.

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