Composite hanging basket structure and construction method for cantilever bridge construction

Abstract

This invention provides a composite hanging basket structure and construction method for cantilever bridge construction. Using segment 0 as the installation foundation, a main truss system extends from the top, with a front upper crossbeam at the end and a front lower crossbeam suspended by hangers. The rear lower crossbeam is anchored to the lower end face of segment 0. The longitudinal beams and the front and rear crossbeams form a segmented bottom basket platform, adapting to the vertical height difference between segments 0 and 1. Cantilever crossbeams are installed at the cantilever ends of the high and low longitudinal beams, with hydraulic columns equipped with axial force sensors installed in the overlapping area. X-shaped adjustable cross braces are installed between the cantilever crossbeams and the auxiliary crossbeams in the middle of the longitudinal beams. During construction, the hanging basket is first assembled and the height difference is roughly adjusted. After assembling the braces, a preload is applied, the braces are adjusted to a bearing state, and the hydraulic columns are unloaded. After pre-arching deformation, concrete is poured. This method solves the problems of high safety hazards, high cost, and low construction efficiency caused by traditional double hanging basket construction when there is a large height difference between adjacent segments in cantilever bridge construction.

Description

Technical Field

[0001] This invention relates to the field of bridge casting construction technology, and in particular to a composite hanging basket structure and construction method for cantilever casting bridges. Background Technology

[0002] In the field of bridge engineering, especially in continuous beam bridges and continuous rigid frame bridges constructed using the cantilever casting method, block 0, as the starting segment of cantilever casting construction, is usually located at the top of the pier. For high-pier, long-span bridges, due to terrain constraints or structural stress design requirements, the design height of block 0 is often relatively large, which brings a series of technical challenges to the subsequent cantilever casting construction.

[0003] In traditional construction techniques, after the construction of block 0 is completed, subsequent standard segments are typically poured segment by segment using symmetrically assembled hanging baskets. However, when block 0 is too high, a significant abrupt change in height occurs between block 0 and adjacent segments 1 or 2. If only one set of conventional hanging baskets is used, its main truss must be installed on the top surface of block 0. The bottom basket system struggles to maintain a reasonable inclination angle while simultaneously meeting the formwork fitting requirements on the higher side of block 0 and the lower side of the segment, as well as the stress safety requirements, significantly increasing the difficulty of structural connections. To address this height difference issue, existing technologies often employ a scheme of simultaneous construction using two sets of hanging baskets: one set of conventional hanging baskets is placed on top of block 0 for pouring the upper standard segments, while another set of smaller hanging baskets or hangers is suspended at the bottom of block 0 or on the side of the beam for pouring the lower segments. This dual-system operation mode easily leads to overlapping of the upper and lower working surfaces.

[0004] The overlapping operations not only pose significant safety hazards such as falling objects and being struck by falling objects, but the two operating systems also interfere with each other during movement and anchoring, greatly increasing the difficulty of construction coordination. Furthermore, the investment in two sets of hanging baskets doubles the equipment rental or manufacturing costs and requires twice the number of work teams, leading to a corresponding increase in labor costs. Moreover, the mutual constraints of overlapping operations prevent parallel flow construction, significantly reducing the construction efficiency of the cantilevered section and extending the segment construction cycle. Therefore, designing a hanging basket system and construction method that can adapt to the large elevation differences between block 0 and adjacent segments, eliminate the risks of overlapping operations, reduce equipment investment, and improve construction efficiency has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0005] The main objective of this invention is to provide a composite hanging basket structure and construction method for cantilever bridge construction, which solves the problems of high safety hazards, high cost, and low construction efficiency caused by traditional double hanging basket construction when there is a large height difference between adjacent segments in cantilever bridge construction.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a composite hanging basket structure for cantilever casting construction bridge, wherein a main truss system is fixedly provided at the top of segment 0, the main truss system extends towards the mid-span and extends beyond the end face of segment 0, and a front upper crossbeam is provided at the top of segment 1 to be cast, and a front lower crossbeam is suspended and connected below the front upper crossbeam by a hanger rod, the height of which is adapted to the elevation of the lower end face of segment 1, and a rear lower crossbeam is anchored to the lower end face of segment 0. Several longitudinally extending longitudinal beams are laid between the front lower crossbeam and the rear lower crossbeam, which together constitute the hanging basket bottom basket system; The hanging basket system is divided into a high-position basket platform and a low-position basket platform. The high-position basket platform includes a rear lower crossbeam and a high-position longitudinal beam vertically anchored thereto. The low-position basket platform includes a front lower crossbeam and a prefabricated low-position longitudinal beam vertically anchored thereto. A vertical height adjustment component is provided at the cantilever height connection between the high-position longitudinal beam and the low-position longitudinal beam.

[0007] In the preferred embodiment, the longitudinal beams include high longitudinal beams and low longitudinal beams. All longitudinal beams are symmetrically arranged along the central axis of segment 0, and the high longitudinal beams and low longitudinal beams are set in a one-to-one correspondence on the plane. A high-level cantilever crossbeam is fixedly installed below the cantilever end of the high-level longitudinal beam, and a low-level cantilever crossbeam is fixedly installed below the cantilever end of the low-level longitudinal beam. Both the high-level and low-level longitudinal beams are arranged perpendicular to the longitudinal beam and together form the transverse support skeleton of the cantilever end of the longitudinal beam.

[0008] In the preferred embodiment, the high-position longitudinal beam and the low-position longitudinal beam have an overlapping area in the horizontal projection, and the vertical height adjustment component is located in this overlapping area. The vertical height adjustment component includes at least two hydraulic columns symmetrically arranged along the central axis of segment 0. The hydraulic columns are vertically installed in the overlapping area, with their upper ends fixedly connected to the bottom surface of the end of the high-position cantilever beam and their lower ends fixedly connected to the top surface of the end of the low-position cantilever beam. An axial force sensor is installed at the connection between the moving end of the hydraulic column and the corresponding crossbeam to detect the axial force acting on the hydraulic column.

[0009] In the preferred embodiment, a first adjustable strut is provided between the high-position cantilever beam and the low-position cantilever beam. The first adjustable strut is arranged at an angle, with its upper end hinged to the end of the high-position cantilever beam away from segment 0, and its lower end hinged to the end of the low-position cantilever beam near segment 0.

[0010] In the preferred embodiment, a high-level auxiliary crossbeam is provided below the middle of the high-level longitudinal beam, and a low-level auxiliary crossbeam is provided below the middle of the low-level longitudinal beam. Both the high-level and low-level auxiliary crossbeams are arranged perpendicular to the longitudinal beams and are fixedly connected to their respective longitudinal beams. A second adjustable strut is provided between the high-position auxiliary crossbeam and the low-position auxiliary crossbeam. The second adjustable strut and the first adjustable strut are arranged in an X-shape on the lateral plane. The upper end of the strut is hinged to the end of the high-position auxiliary crossbeam, and the lower end is hinged to the end of the low-position auxiliary crossbeam.

[0011] In the preferred embodiment, the transverse widths of the high-position auxiliary beam and the low-position auxiliary beam are equal, and their transverse widths are greater than the widths of the high-position cantilever beam and the low-position cantilever beam.

[0012] In the preferred embodiment, the first adjustable strut and the second adjustable strut have the same structure; The first adjustable strut includes a hollow first outer sleeve, a first inner sleeve fitted inside the first outer sleeve, and a first self-locking screw provided along the axial direction in the cavities of the first outer sleeve and the first inner sleeve. One end of the first self-locking screw is fixedly connected to a first support at the center of the top of the first inner sleeve, and the other end is threadedly engaged with a first central nut seat at the bottom of the inner side of the first outer sleeve. The second adjustable strut includes a hollow second outer sleeve and a second inner sleeve fitted inside the second outer sleeve. The cavities inside the second outer sleeve and the second inner sleeve are provided with a second self-locking screw along the axial direction. One end of the second self-locking screw is fixedly connected to the second support at the center of the top of the second inner sleeve, and the other end is threadedly engaged with the second center nut seat at the bottom of the inner side of the second outer sleeve.

[0013] In the preferred embodiment, both ends of the first adjustable strut and the second adjustable strut are hinged to the ends of the corresponding crossbeams via ear plates and pin structures. Among them, the first outer sleeve of the first adjustable support rod is provided with an axial rotation pair between the first outer sleeve and the corresponding first ear plate, and the first inner sleeve is rigidly fixedly connected to the corresponding second ear plate. An axial rotation pair is provided between the second outer sleeve of the second adjustable support rod and the corresponding first ear plate, and the second inner sleeve is rigidly fixedly connected to the corresponding second ear plate. Both the first self-locking screw of the first adjustable strut and the second self-locking screw of the second adjustable strut adopt trapezoidal self-locking threads.

[0014] A construction method for a composite hanging basket structure for cantilever bridge construction, the method comprising: S1. Install and fix the main truss system at the top of the formed segment 0, so that the main truss system extends towards the middle of the span and extends beyond the end face of segment 0. Install the front upper crossbeam at the end of the main truss system corresponding to the position of segment 1 to be poured. S2. Anchor the lower rear crossbeam to the lower end face of segment 0, suspend the lower front crossbeam below the upper front crossbeam using a hanger, and adjust the height of the lower front crossbeam to match the elevation of the lower end face of segment 1. S3. Lay high-level longitudinal beams and low-level longitudinal beams symmetrically between the front lower crossbeam and the rear lower crossbeam. Fix high-level cantilever crossbeams at the cantilever ends of high-level longitudinal beams and low-level cantilever crossbeams at the cantilever ends of low-level longitudinal beams. At the same time, fix high-level auxiliary crossbeams and low-level auxiliary crossbeams in the middle of the two sets of longitudinal beams respectively. S4. Install hydraulic columns in the overlapping area, and adjust the vertical height difference between the high and low bottom basket platforms initially through the hydraulic columns. Then assemble the first and second adjustable support rods arranged in an X-shape, and hinge the two ends of the support rods to the corresponding crossbeams through ear plates and pins. S5. Apply a construction simulation preload to the hanging basket bottom basket system. After completing the deformation stability and adjustable strut load adaptation adjustment of the bottom basket, lay the formwork and pour the No. 1 segment concrete. S6. After the concrete of segment 1 reaches the design strength, remove the formwork and release the locking state of the adjustable struts. Adjust the high and low bottom basket platform to the height difference state of the next segment using hydraulic columns, move the hanging basket forward to the construction position of the next segment, and repeat the above procedures to complete the cantilever casting of the subsequent beam segments.

[0015] In the preferred embodiment, in step S5, the method for adjusting the load of the adjustable strut is as follows: the axial force of the hydraulic column under the pre-compression condition is monitored in real time by the axial force sensor, and the length of the two adjustable struts is adjusted steplessly by rotating the first self-locking screw and the second self-locking screw so that both the first adjustable strut and the second adjustable strut enter the axial pressure state, while the hydraulic column is completely unloaded to the point that it does not bear any tensile or compressive load. Continue to fine-tune the length of the adjustable struts so that the high and low bottom basket platforms form a slight pre-arch deformation to offset the subsequent deflection deformation of the concrete pouring, and then rely on the self-locking characteristics of the trapezoidal self-locking thread to lock the length of the struts. During the concrete pouring process, the downward overturning force and compressive force at the cantilever end of the basket are all resisted by the axial bearing pressure of the two adjustable struts arranged in an X shape. The outer sleeve is adjusted by the screw through the axial rotation pair, while the inner sleeve maintains rigid force transmission, ensuring the linearity and structural stability of the basket system.

[0016] This invention provides a composite hanging basket structure and construction method for cantilever bridge construction. A single composite hanging basket structure can accommodate the vertical height difference between segment 0 and segment 1 to be poured, eliminating the safety hazards of traditional double hanging basket cross-operation and avoiding interference between the two construction systems, thus significantly reducing the difficulty of construction coordination. Through the segmented setting of the high-level and low-level bottom basket platforms, the bottom formwork can continuously fit against the bottom surface of the beam, eliminating assembly gaps caused by abrupt changes in elevation, ensuring uniform stress on the bottom basket system, and improving the stability of the construction structure.

[0017] The cantilever connection area of ​​the hanging basket bottom uses hydraulic columns and X-shaped adjustable struts working together. The hydraulic columns only handle vertical height adjustment and are completely unloaded during pouring, preventing guide damage to hydraulic components due to overturning and compressive forces, and extending the service life of the core adjustment components. The X-shaped adjustable struts bear axial pressure throughout, effectively resisting the downward overturning force at the cantilever end and the deflection force in the middle of the bottom basket, converting concentrated loads into uniform axial force transmission, optimizing the structural stress path, and preventing deformation caused by excessive local stress.

[0018] The adjustable strut employs a combination structure of nested sleeves and self-locking screws. The sleeves, as the main pressure-bearing components, are adapted to heavy-duty construction requirements, while the screws enable stepless length adjustment and mechanical self-locking. Adjustment is simple, and there is no risk of retraction after locking. Both ends of the strut utilize a hinged axial rotation pair design, which adapts to changes in elevation and angular deflections caused by adjustment movements, ensuring the strut is always under pure axial force and improving pressure-bearing efficiency. The auxiliary crossbeam has a wider transverse width than the cantilever crossbeam, allowing the two struts to be spatially staggered to avoid interference and widening the support arm, thus enhancing overall deformation resistance.

[0019] The supporting construction method relies on the matching and adjustment of preload and strut load to form a pre-arch shape of the basket that offsets casting deformation, precisely controlling the beam alignment and improving the forming quality. The construction process does not require disassembling the main body of the basket, enabling multi-segment continuous cyclic construction, reducing equipment investment and labor configuration, lowering construction costs, and significantly improving the construction efficiency and overall safety of cantilever bridge casting. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall construction elevation of the present invention; Figure 2 This is an overall structural diagram of the hanging basket bottom basket system of the present invention; Figure 3 This is a partial connection structure diagram of the vertical height adjustment component of the present invention; Figure 4 This is a structural diagram of the adjustable strut arrangement of the present invention; Figure 5 This is a cross-sectional view of the adjustable strut structure of the present invention.

[0021] In the diagram: Segment 0 (1); Main Truss System (2); Front Upper Crossbeam (3); Front Lower Crossbeam (4); Rear Lower Crossbeam (5); Longitudinal Beam (6); High-position Longitudinal Beam (601); Low-position Longitudinal Beam (602); Segment 1 (7); High-position Cantilever Crossbeam (8); Low-position Cantilever Crossbeam (9); Hydraulic Column (10); First Adjustable Support Rod (11); First Outer Sleeve (1101); First Inner Sleeve (1102); First Self-locking Screw (1103); First Support (1104); First Central Nut Seat (1105); High-position Auxiliary Crossbeam (12); Low-position Auxiliary Crossbeam (13); Second Adjustable Support Rod (14); Second Outer Sleeve (1401); Second Inner Sleeve (1402); Second Self-locking Screw (1403); Second Support (1404); Second Central Nut Seat (1405); Ear Plate (15); First Ear Plate (1501); Second Ear Plate (1502); Axial Force Sensor (16); Pin (17); Hanger Rod (18). Detailed Implementation

[0022] Example 1 like Figure 1-5 As shown, a composite hanging basket structure for cantilever casting construction of a bridge is provided. The top of segment 0 1 is fixedly provided with a main truss system 2. The main truss system 2 extends towards the mid-span and extends beyond the end face of segment 0 1. The top of the main truss system 2 is provided with a front upper crossbeam 3 corresponding to the segment 1 7 to be cast. The front lower crossbeam 4 is suspended and connected to the lower part of the front upper crossbeam 3 by a hanger 18. Its height is adapted to the elevation of the lower end face of segment 1 7. The rear lower crossbeam 5 is anchored to the lower end face of segment 0 1. Several longitudinally extending longitudinal beams 6 are laid between the front lower crossbeam 4 and the rear lower crossbeam 5, which together form the hanging basket bottom basket system. The hanging basket system is divided into a high-position basket platform and a low-position basket platform. The high-position basket platform includes a rear lower crossbeam 5 and a high-position longitudinal beam 601 vertically anchored thereto. The low-position basket platform includes a front lower crossbeam 4 and a prefabricated, vertically anchored low-position longitudinal beam 602. A vertical height adjustment component is provided at the cantilever height connection between the high-position longitudinal beam 601 and the low-position longitudinal beam 602.

[0023] This embodiment discloses a composite hanging basket structure for cantilever bridge construction. The main truss system 2 is fixed at the top of segment 0 1 and extends towards the mid-span, providing a stable load-bearing support for the front-end components. The front upper crossbeam 3 and the hanger rod 18 cooperate to suspend the front lower crossbeam 4, and the rear lower crossbeam 5 is anchored to the lower end face of segment 0 1. The high and low bottom basket platforms are adapted to the elevation difference between segment 0 1 and segment 1 7, respectively, solving the problem that traditional bottom baskets cannot adapt to segment elevation differences. The high longitudinal beam 601 and the low longitudinal beam 602 form a continuous load-bearing skeleton. The hydraulic columns 10 in the overlapping area complete the coarse adjustment of the vertical elevation difference. The first adjustable strut 11 and the second adjustable strut 14 arranged in an X shape bear the casting load, and the axial force sensor 16 monitors the stress state of the hydraulic columns 10. The adjustable strut adopts a combination structure of sleeve nesting and self-locking screw, and the hinged axial rotation pair adapts to the angle change. The width of the auxiliary crossbeam is greater than that of the cantilever crossbeam to avoid cross interference. The overall structure can quickly adapt to segment height differences, resist cantilever overturning and flexural deformation, and improve beam segment alignment accuracy and construction safety.

[0024] In the preferred embodiment, the longitudinal beam 6 includes a high longitudinal beam 601 and a low longitudinal beam 602. All longitudinal beams are symmetrically arranged along the central axis of segment 0 1. The high longitudinal beam 601 and the low longitudinal beam 602 are set one-to-one in the plane. A high-level cantilever beam 8 is fixedly installed below the cantilever end of the high-level longitudinal beam 601, and a low-level cantilever beam 9 is fixedly installed below the cantilever end of the low-level longitudinal beam 602. Both the high-level longitudinal beam 601 and the low-level longitudinal beam 602 are arranged perpendicular to the longitudinal beam 6, and together they form the transverse support skeleton of the cantilever end of the longitudinal beam 6.

[0025] The high-level bottom basket platform corresponds to the high end face of segment 0 (1), and the low-level bottom basket platform corresponds to the low end face of segment 1 (7) to be poured. The vertical height difference between the two perfectly matches the difference between the end faces of the two segments. Traditional integrated bottom baskets are prone to problems such as formwork suspension and uneven stress due to elevation differences. The segmented high and low platforms allow the bottom formwork to continuously fit against the bottom surface of the beam, eliminating assembly gaps. The high-level longitudinal beam 601 and the low-level longitudinal beam 602 are symmetrically arranged along the central axis, so that the overall load of the bottom basket is evenly transferred to the front and rear crossbeams, avoiding the bending of the longitudinal beams caused by concentrated load on one side. The longitudinal beam 6 provides a direct bearing surface for the bottom formwork, reinforcing bars, and construction equipment. The longitudinal extension layout maximizes the bearing area and adapts to the construction needs of wide beam segments.

[0026] In the preferred embodiment, the high longitudinal beam 601 and the low longitudinal beam 602 have an overlapping area in the horizontal projection, and the vertical height adjustment component is located in the overlapping area. The vertical height adjustment assembly includes at least two hydraulic columns 10 symmetrically arranged along the central axis of segment 0 1. The hydraulic columns 10 are vertically installed in the overlapping area, with their upper ends vertically fixed to the bottom surface of the end of the high-position cantilever beam 8 and their lower ends vertically fixed to the top surface of the end of the low-position cantilever beam 9. An axial force sensor 16 is provided at the connection between the moving end of the hydraulic column 10 and the corresponding crossbeam to detect the axial force acting on the hydraulic column 10.

[0027] The high-position cantilever beam 8 and the low-position cantilever beam 9 are vertically fixed to the cantilever ends of the longitudinal beams to reinforce the local stiffness of the free ends of the longitudinal beams. The cantilever ends are weak areas in the load-bearing structure of the basket, and the downward bending moment generated by concrete pouring can easily cause plastic deformation at the ends of the longitudinal beams. Adding cantilever beams can form a transverse rigid frame to disperse the concentrated stress at the cantilever ends. The overlapping area of ​​the horizontal projections of the high and low longitudinal beams is the core of the load-bearing connection between the high and low platforms, and also the concentrated transmission point of the cantilever overturning force and shear force. The hydraulic columns 10 are set here to precisely control the vertical height difference at the connection point. The symmetrical arrangement of the hydraulic columns 10 can ensure that the load on both sides of the basket is synchronized during the adjustment process, preventing unilateral tilting. The axial force sensor 16 directly collects the axial force data of the hydraulic columns 10, providing a quantitative basis for subsequent strut load adjustment and avoiding damage to hydraulic components due to overload.

[0028] In the preferred embodiment, a first adjustable support rod 11 is provided between the high-position cantilever beam 8 and the low-position cantilever beam 9. The first adjustable support rod 11 is arranged at an angle, with its upper end hinged to the end of the high-position cantilever beam 8 away from segment 01, and its lower end hinged to the end of the low-position cantilever beam 9 near segment 01.

[0029] In the preferred embodiment, a high-level auxiliary crossbeam 12 is provided below the middle of the high-level longitudinal beam 601, and a low-level auxiliary crossbeam 13 is provided below the middle of the low-level longitudinal beam 602. The high-level auxiliary crossbeam 12 and the low-level auxiliary crossbeam 13 are both arranged perpendicular to the longitudinal beam 6 and are fixedly connected to the corresponding longitudinal beam 6 respectively. A second adjustable support rod 14 is provided between the high-position auxiliary crossbeam 12 and the low-position auxiliary crossbeam 13. The second adjustable support rod 14 and the first adjustable support rod 11 are arranged in an X-shape on the lateral plane. The upper end of the second adjustable support rod 14 is hinged to the end of the high-position auxiliary crossbeam 12, and the lower end is hinged to the end of the low-position auxiliary crossbeam 13.

[0030] The high-position auxiliary beam 12 and the low-position auxiliary beam 13 are positioned at the 1 / 3 span position near the cantilever end of the longitudinal beam 6. This area is the region of maximum stress concentration during the flexural deformation of the basket and a key location for the coupling of bending moment and shear force. Placing the auxiliary beams here allows for precise support with the second adjustable strut 14, effectively suppressing downward deflection in the middle of the basket. The auxiliary beams are arranged parallel to the cantilever beams, further enhancing the lateral stiffness of the longitudinal beams and preventing lateral torsion under heavy loads. The high-position auxiliary beam 12 and the low-position auxiliary beam 13 are of equal width and larger than the cantilever beam, allowing the hinge points of the two adjustable struts to be staggered in the lateral space. This fundamentally prevents component interference when the X-shaped struts cross, while also widening the support arm and improving the overall resistance to deformation.

[0031] In the preferred embodiment, the transverse widths of the high-position auxiliary beam 12 and the low-position auxiliary beam 13 are equal, and their transverse widths are greater than the widths of the high-position cantilever beam 8 and the low-position cantilever beam 9.

[0032] The first adjustable strut 11 and the second adjustable strut 14 are arranged in an X-shape, forming a spatial triangular stable system. During concrete pouring, a downward overturning moment will be generated at the cantilever end of the basket around the connection point. The inclined arrangement of the first adjustable strut 11 can decompose the overturning moment into axial pressure and lateral force. The axial pressure is borne by the strut itself, and the lateral force is offset by the rigid connection between the crossbeam and the longitudinal beam. The second adjustable strut 14 is located in the middle of the basket and mainly resists the downward bending moment caused by the pouring load, forming a two-way constraint with the first adjustable strut 11. The X-shaped structure can resist overturning, shear, and bending forces simultaneously, transforming concentrated loads into uniform axial pressure and avoiding excessive local stress. The two struts have complementary forces; the overturning force at the cantilever end is dominated by the upper strut, and the bending force in the middle is dominated by the lower strut. The overall force path is clear, and the structural stability is greatly improved.

[0033] In the preferred embodiment, the first adjustable support rod 11 and the second adjustable support rod 14 have the same structure; The first adjustable support rod 11 includes a hollow first outer sleeve 1101, and a first inner sleeve 1102 is sleeved inside the first outer sleeve 1101. The first self-locking screw 1103 is provided along the axial direction in the cavity of the first outer sleeve 1101 and the first inner sleeve 1102. One end of the first self-locking screw 1103 is fixedly connected to the first support 1104 at the center of the top of the first inner sleeve 1102, and the other end is threadedly engaged with the first center nut seat 1105 at the bottom of the inner side of the first outer sleeve 1101. The second adjustable support rod 14 includes a hollow second outer sleeve 1401, and a second inner sleeve 1402 is sleeved inside the second outer sleeve 1401. The inner cavities of the second outer sleeve 1401 and the second inner sleeve 1402 are provided with a second self-locking screw 1403 along the axial direction. One end of the second self-locking screw 1403 is fixedly connected to the second support 1404 at the top center of the second inner sleeve 1402, and the other end is threadedly engaged with the second center nut seat 1405 at the bottom of the inner side of the second outer sleeve 1401.

[0034] In the preferred embodiment, both ends of the first adjustable support rod 11 and the second adjustable support rod 14 are hinged to the ends of the corresponding crossbeams through the ear plate 15 and the pin shaft 17 structure. Among them, an axial rotation pair is provided between the first outer sleeve 1101 of the first adjustable support rod 11 and the corresponding first ear plate 1501, and the first inner sleeve 1102 and the corresponding second ear plate 1502 are rigidly fixedly connected. An axial rotation pair is provided between the second outer sleeve 1401 of the second adjustable support rod 14 and the corresponding first ear plate 1501, and the second inner sleeve 1402 is rigidly fixedly connected to the corresponding second ear plate 1502. Both the first self-locking screw 1103 of the first adjustable support rod 11 and the second self-locking screw 1403 of the second adjustable support rod 14 adopt trapezoidal self-locking threads.

[0035] The adjustable strut employs a nested structure of an outer and inner sleeve. The sleeve serves as the primary pressure-bearing component, adapting to the heavy-load requirements of concrete pouring, while the lead screw is solely responsible for length adjustment and locking, achieving functional division. During adjustment, rotating the self-locking lead screw drives the inner sleeve to extend or retract. The axial rotational joint between the outer sleeve and the ear plate accommodates the lead screw's rotation, preventing the strut from jamming due to circumferential constraints. The rigid connection between the inner sleeve and the ear plate ensures that the pressure transmission does not diminish. The hinged structure of the ear plates 15 at both ends and the pin 16 can accommodate the strut angle deflection caused by changes in the height difference of the platform, ensuring that the strut is always under pure axial force, improving pressure-bearing efficiency. The trapezoidal self-locking thread has a large tooth contact area and high root strength. When stationary, it achieves mechanical self-locking through frictional resistance. After adjustment, no additional locking components are needed, allowing it to withstand axial pressure for extended periods without shrinking, meeting the load stability requirements of continuous pouring.

[0036] Example 2 Further explanation in conjunction with Example 1, such as Figure 1-5 The structure shown illustrates a construction method for a composite hanging basket structure for cantilever bridge construction, the method comprising: S1. Install and fix the main truss system 2 at the top of the formed segment 0 1, so that the main truss system 2 extends towards the middle of the span and extends out of the end face of segment 0 1. Install the front upper crossbeam 3 at the end of the main truss system 2 corresponding to the position of segment 1 7 to be poured. S2. Anchor the lower rear crossbeam 5 to the lower end face of segment 0 1, suspend the lower front crossbeam 4 below the upper front crossbeam 3 through the hanger 18, and adjust the height of the lower front crossbeam 4 to be consistent with the elevation of the lower end face of segment 1 7. S3. A high-position longitudinal beam 601 and a low-position longitudinal beam 602 are symmetrically laid between the front lower crossbeam 4 and the rear lower crossbeam 5. A high-position cantilever crossbeam 8 is fixed at the cantilever end of the high-position longitudinal beam 601 and a low-position cantilever crossbeam 9 is fixed at the cantilever end of the low-position longitudinal beam 602. At the same time, a high-position auxiliary crossbeam 12 and a low-position auxiliary crossbeam 13 are fixed in the middle of the two sets of longitudinal beams respectively. S4. Install hydraulic columns 10 in the overlapping area, and adjust the vertical height difference between the high and low bottom basket platforms initially through the hydraulic columns 10. Then assemble the first adjustable support rod 11 and the second adjustable support rod 14 arranged in an X-shape. Hinge the two ends of the support rods to the corresponding crossbeams through ear plates 15 and pins 17. S5. Apply a construction simulation preload to the hanging basket bottom basket system. After completing the deformation stability and adjustable strut load adaptation adjustment of the bottom basket, lay the formwork and pour concrete for segment 7 of section 1. S6. After the concrete of segment 1, section 7 reaches the design strength, remove the formwork and release the locking state of the adjustable struts. Adjust the high and low bottom basket platform to the height difference state of the next segment using the hydraulic column 10, move the hanging basket forward to the construction position of the next segment, and repeat the above procedures to complete the cantilever casting of the subsequent beam segments.

[0037] In the preferred embodiment, in step S5, the method for adjusting the load of the adjustable strut is as follows: the axial force of the hydraulic column 10 under the pre-compression condition is monitored in real time by the axial force sensor 16, and the length of the two adjustable struts is adjusted steplessly by rotating the first self-locking screw 1103 and the second self-locking screw 1403 so that the first adjustable strut 11 and the second adjustable strut 14 both enter the axial pressure state, and at the same time the hydraulic column 10 is completely unloaded to the point that it does not bear any tensile or compressive load; Continue to fine-tune the length of the adjustable struts so that the high and low bottom basket platforms form a slight pre-arch deformation to offset the subsequent deflection deformation of the concrete pouring, and then rely on the self-locking characteristics of the trapezoidal self-locking thread to lock the length of the struts. During the concrete pouring process, the downward overturning force and compressive force at the cantilever end of the basket are all resisted by the axial bearing pressure of the two adjustable struts arranged in an X shape. The outer sleeve is adjusted by the screw through the axial rotation pair, while the inner sleeve maintains rigid force transmission, ensuring the linearity and structural stability of the basket system.

[0038] The construction method in this embodiment relies on the characteristics of the composite hanging basket structure and follows the conventional construction process of cantilever casting. Through segmented assembly, pre-stressing and shaping, load adaptation, and cyclical construction, the method improves the quality of beam segment forming while ensuring construction efficiency. Construction begins with the positioning and installation of the main truss system 2 and the front and rear crossbeams, fixing the longitudinal frame of the bottom basket. Then, the vertical height difference between the high and low platforms is roughly adjusted using hydraulic columns 10. Finally, X-shaped adjustable struts are assembled to form a complete support system, laying the structural foundation for subsequent casting.

[0039] The preloading simulation stage can eliminate assembly gaps and elastic deformations in the basket system in advance, allowing the structure to enter a stable stress state beforehand and avoiding sudden deformations during pouring that could affect the beam's alignment. During the preloading process, the data from the axial force sensor 16 is used as the core basis to gradually adjust the length of the adjustable struts, ensuring that the struts are fully under axial pressure. At the same time, the hydraulic columns 10 are completely unloaded, preventing problems such as guide wear and seal failure caused by tensile and compressive loads on the hydraulic components.

[0040] Fine-tuning the strut length allows for a slight pre-arch deformation in the high and low base basket platforms. This pre-arching amount matches the theoretical deflection of the subsequent concrete pouring. During pouring, the downward deflection of the base basket cancels out the pre-arch deformation, ensuring that the bottom surface alignment of the beam segment meets design requirements. During pouring, the X-shaped strut continuously bears the axial pressure, the trapezoidal self-locking thread maintains its length lock, the outer sleeve rotating joint adapts to the real-time stress state, and the inner sleeve rigidly transmits the supporting force, maintaining the stability of the base basket structure.

[0041] After the segmental construction is completed, the self-locking of the struts is released, and the bottom basket platform is adjusted to match the height difference of the next segment using the hydraulic column 10. The hanging basket is then moved forward, and the construction process is repeated. This method eliminates the need to disassemble the main body of the bottom basket, enabling continuous construction of multiple segments. While simplifying the process, it effectively solves the problems of difficulty in adapting to height differences and poor alignment control of traditional hanging baskets by relying on strut bearing and pre-arching adjustment technology, thereby improving the overall construction quality and safety of cantilever bridge construction.

[0042] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A composite form traveler structure for cantilever construction of a bridge, characterized in that: The top of segment 0 (1) is fixed with a main truss system (2). The main truss system (2) extends towards the middle of the span and extends out of the end face of segment 0 (1). The top of the main truss system (2) is provided with a front upper crossbeam (3) corresponding to the segment 1 (7) to be poured. The front lower crossbeam (4) is suspended and connected to the front upper crossbeam (3) by a hanger (18). Its height is matched with the elevation of the lower end face of segment 1 (7). The rear lower crossbeam (5) is anchored to the lower end face of segment 0 (1). Several longitudinally extending longitudinal beams (6) are laid between the front lower crossbeam (4) and the rear lower crossbeam (5) to form a hanging basket bottom basket system. ​ The hanging basket system is divided into a high-position basket platform and a low-position basket platform. The high-position basket platform includes a rear lower crossbeam (5) and a high-position longitudinal beam (601) vertically anchored thereto. The low-position basket platform includes a front lower crossbeam (4) and a prefabricated low-position longitudinal beam (602) vertically anchored thereto. A vertical height adjustment component is provided at the cantilever height connection between the high-position longitudinal beam (601) and the low-position longitudinal beam (602).

2. The composite form traveler structure for cantilever construction of bridge according to claim 1, characterized in that: The longitudinal beam (6) includes a high longitudinal beam (601) and a low longitudinal beam (602). All longitudinal beams are symmetrically arranged along the central axis of segment 0 (1). The high longitudinal beam (601) and the low longitudinal beam (602) are set one-to-one in the plane. A high-level cantilever beam (8) is fixedly installed below the cantilever end of the high-level longitudinal beam (601), and a low-level cantilever beam (9) is fixedly installed below the cantilever end of the low-level longitudinal beam (602). The high-level longitudinal beam (601) and the low-level longitudinal beam (602) are both arranged perpendicular to the longitudinal beam (6) and together form the transverse support skeleton of the cantilever end of the longitudinal beam (6).

3. The cantilever construction composite hanging basket structure for bridge according to claim 2, characterized in that: The high longitudinal beam (601) and the low longitudinal beam (602) have an overlapping area in the horizontal projection, and the vertical height adjustment component is located in the overlapping area; The vertical height adjustment component includes at least two hydraulic columns (10) symmetrically arranged along the central axis of segment 0 (1). The hydraulic columns (10) are vertically installed in the overlapping area, with their upper ends vertically fixed to the bottom surface of the end of the high-position cantilever beam (8) and their lower ends vertically fixed to the top surface of the end of the low-position cantilever beam (9). An axial force sensor (16) is provided at the connection between the moving end of the hydraulic column (10) and the corresponding crossbeam to detect the axial force acting on the hydraulic column (10).

4. The composite form traveler structure for cantilever construction of bridge according to claim 3, characterized in that: A first adjustable strut (11) is provided between the high-position cantilever beam (8) and the low-position cantilever beam (9). The first adjustable strut (11) is arranged at an angle. Its upper end is hinged to the end of the high-position cantilever beam (8) away from segment 0 (1), and its lower end is hinged to the end of the low-position cantilever beam (9) near segment 0 (1).

5. The composite hanging basket structure for cantilevered bridge construction according to claim 4, characterized in that: A high-level auxiliary crossbeam (12) is provided below the middle of the high-level longitudinal beam (601), and a low-level auxiliary crossbeam (13) is provided below the middle of the low-level longitudinal beam (602). The high-level auxiliary crossbeam (12) and the low-level auxiliary crossbeam (13) are arranged perpendicular to the longitudinal beam (6) and are fixedly connected to the corresponding longitudinal beam (6). A second adjustable strut (14) is provided between the high-position auxiliary crossbeam (12) and the low-position auxiliary crossbeam (13). The second adjustable strut (14) and the first adjustable strut (11) are arranged in an X-shape on the lateral plane. The upper end of the strut (14) is hinged to the end of the high-position auxiliary crossbeam (12), and the lower end is hinged to the end of the low-position auxiliary crossbeam (13).

6. The composite hanging basket structure for cantilevered bridge construction according to claim 5, characterized in that: The transverse widths of the high-position auxiliary beam (12) and the low-position auxiliary beam (13) are equal, and their transverse widths are greater than the widths of the high-position cantilever beam (8) and the low-position cantilever beam (9).

7. The composite hanging basket structure for cantilevered bridge construction according to claim 5, characterized in that: The first adjustable strut (11) and the second adjustable strut (14) have the same structure; The first adjustable support rod (11) includes a hollow first outer sleeve (1101), and a first inner sleeve (1102) is sleeved inside the first outer sleeve (1101). The first outer sleeve (1101) and the first inner sleeve (1102) are provided with a first self-locking screw (1103) along the axial direction in the cavity of the first outer sleeve (1101) and the first inner sleeve (1102). One end of the first self-locking screw (1103) is fixedly connected to the first support (1104) at the top center of the first inner sleeve (1102), and the other end is threadedly engaged with the first center nut seat (1105) at the bottom of the inner side of the first outer sleeve (1101). The second adjustable support rod (14) includes a hollow second outer sleeve (1401) and a second inner sleeve (1402) sleeved inside the second outer sleeve (1401). The second self-locking screw (1403) is provided along the axial direction in the cavity of the second outer sleeve (1401) and the second inner sleeve (1402). One end of the second self-locking screw (1403) is fixedly connected to the second support (1404) at the top center of the second inner sleeve (1402), and the other end is threadedly engaged with the second center nut seat (1405) at the bottom of the inner side of the second outer sleeve (1401).

8. The composite hanging basket structure for cantilevered bridge construction according to claim 7, characterized in that: Both ends of the first adjustable strut (11) and the second adjustable strut (14) are hinged to the ends of the corresponding crossbeams through ear plates (15) and pins (17); Among them, the first outer sleeve (1101) of the first adjustable support rod (11) is provided with an axial rotation pair between the first outer sleeve (1101) and the corresponding first ear plate (1501), and the first inner sleeve (1102) is rigidly fixedly connected with the corresponding second ear plate (1502). The second adjustable support rod (14) has an axial rotation pair between its second outer sleeve (1401) and the corresponding first ear plate (1501), and the second inner sleeve (1402) and the corresponding second ear plate (1502) are rigidly fixedly connected. The first self-locking screw (1103) of the first adjustable support rod (11) and the second self-locking screw (1403) of the second adjustable support rod (14) both adopt trapezoidal self-locking threads.

9. A construction method for a composite hanging basket structure for cantilever bridge construction according to any one of claims 1-8, characterized in that: The method includes: S1. Install the main truss system (2) at the top of the formed segment 0 (1), so that the main truss system (2) extends towards the middle of the span and extends out of the end face of segment 0 (1). Install the front upper crossbeam (3) at the end of the main truss system (2) corresponding to the position of segment 1 (7) to be poured. S2. Anchor the lower rear crossbeam (5) to the lower end face of segment 0 (1), suspend the lower front crossbeam (4) below the upper front crossbeam (3) through the hanger (18), and adjust the height of the lower front crossbeam (4) to be consistent with the elevation of the lower end face of segment 1 (7). S3. A high-level longitudinal beam (601) and a low-level longitudinal beam (602) are symmetrically laid between the front lower crossbeam (4) and the rear lower crossbeam (5). A high-level cantilever crossbeam (8) is fixed at the cantilever end of the high-level longitudinal beam (601) and a low-level cantilever crossbeam (9) is fixed at the cantilever end of the low-level longitudinal beam (602). At the same time, a high-level auxiliary crossbeam (12) and a low-level auxiliary crossbeam (13) are fixed in the middle of the two sets of longitudinal beams respectively. S4. Install hydraulic columns (10) in the overlapping area, adjust the vertical height difference between the high and low bottom basket platforms initially through the hydraulic columns (10), and then assemble the first adjustable support rod (11) and the second adjustable support rod (14) arranged in an X-shape. Hinge the two ends of the support rods to the corresponding crossbeams through ear plates (15) and pins (17). S5. Apply construction simulation preload to the hanging basket bottom basket system, and after completing the deformation stability and adjustable strut load adaptation adjustment of the bottom basket, lay the template and pour the No. 1 segment (7) concrete. S6. After the concrete of segment 1 (7) reaches the design strength, remove the formwork and release the locking state of the adjustable support rod. Adjust the high and low bottom basket platform to the next segment height difference state through the hydraulic column (10), move the hanging basket forward to the next segment construction position, and repeat the above procedures to complete the cantilever casting of the subsequent beam segment.

10. The construction method of a composite hanging basket structure for cantilever bridge construction according to claim 9, characterized in that: In step S5, the method for adjusting the load of the adjustable strut is as follows: the axial force of the hydraulic column (10) under the pre-compression condition is monitored in real time by the axial force sensor (16), the length of the two adjustable struts is adjusted steplessly by rotating the first self-locking screw (1103) and the second self-locking screw (1403) so that the first adjustable strut (11) and the second adjustable strut (14) both enter the axial pressure state, and the hydraulic column (10) is completely unloaded to the point that it does not bear any tensile or compressive load. Continue to fine-tune the length of the adjustable struts so that the high and low bottom basket platforms form a slight pre-arch deformation to offset the subsequent deflection deformation of the concrete pouring, and then rely on the self-locking characteristics of the trapezoidal self-locking thread to lock the length of the struts. During the concrete pouring process, the downward overturning force and compressive force at the cantilever end of the basket are all resisted by the axial bearing pressure of the two adjustable struts arranged in an X shape. The outer sleeve is adjusted by the screw through the axial rotation pair, while the inner sleeve maintains rigid force transmission, ensuring the linearity and structural stability of the basket system.

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