Suspension supporting system of steel-concrete combined section and construction method

Abstract

The invention discloses a suspension supporting system for a steel-concrete combined section and a construction method, and belongs to the technical field of construction equipment. The suspension supporting system comprises a suspension bracket subsystem, a cantilever beam subsystem, an embedded part subsystem and a prestressed steel strand pre-tensioning subsystem; the hanging bracket subsystem is used for bearing the weight of a steel mixed section steel beam and a small amount of concrete during pouring, and the cantilever beam subsystem and the embedded part subsystem are matched to bear the vast majority of the weight of the concrete during pouring of the steel mixed section. The prestressed steel strand pre-tensioning subsystem is used for counteracting tension of a web embedded part on the upper portion of the steel-concrete combined section during concrete pouring and controlling the bending moment. The problem that in the construction process, when the steel-concrete combined section is in place, due to construction and machining errors, a steel-concrete interface is difficult to be attached closely is solved; therefore, the problem that the load transmission at the steel-concrete joint is only completely borne by a welding seam between the embedded part and the steel-concrete combined section steel beam is solved.

Description

Technical Field

[0001] This invention belongs to the field of construction equipment technology, specifically relating to a suspension support system and construction method for a steel-concrete composite section. Background Technology

[0002] The steel-concrete interface section is the core part where the steel structure and the concrete structure work together to bear the load. Its interface performance directly determines the safety and durability of the overall structure. As a key component for transmitting shear force, axial force and bending moment, the steel-concrete interface embedded part is the core guarantee for realizing the "reliable connection and joint operation" of the two materials. Its design, processing and installation quality are crucial to the performance of the interface section.

[0003] The construction of the steel-concrete composite section mainly adopts the scaffolding method or cantilever hoisting. The scaffolding method is safe and reliable, but the construction progress is slow and the material consumption is high. The cantilever hoisting method is convenient and fast, but it has high requirements for hoisting equipment and construction technology, especially in terms of the force on the crane during the concrete pouring of the steel-concrete composite section or the measures taken at the steel-concrete interface to coordinate the force on the crane.

[0004] Currently, the main method for cantilever erection of steel-concrete composite sections is to use a bridge crane and pre-embedded parts at the steel-concrete interface to transfer the load. These components jointly bear the weight of the steel beams and concrete during concrete pouring. However, the bridge crane and steel strands have lower stiffness than the pre-embedded parts, so most of the load on the newly poured concrete is borne by the pre-embedded parts at the steel-concrete interface. However, in actual construction, due to construction and processing errors, it is difficult for the steel-concrete interface to fit tightly during placement. This results in the load transfer at the steel-concrete connection being entirely borne by the weld between the pre-embedded parts and the steel beams of the steel-concrete composite section. Furthermore, since the construction of the steel-concrete composite section involves high-altitude work, the weld quality is difficult to meet expectations, posing significant safety hazards.

[0005] The present invention aims to propose a suspension support system and construction method for steel-concrete composite sections that is simple in structure, easy to install and disassemble, and can improve the problem of rubber plate aging and damage caused by long-term movement and deformation of bridge expansion joints, and reduce maintenance frequency and cost. Summary of the Invention

[0006] To address the aforementioned problems in the existing technology, this invention provides a suspension support system and construction method for a steel-concrete composite section.

[0007] The objective of this invention can be achieved through the following technical solutions: A suspension support system for a steel-concrete composite section includes a hanger subsystem, a cantilever beam subsystem, an embedded component subsystem, and a prestressed steel strand pretensioning subsystem. The hanger subsystem spans and is anchored to the front end of a constructed cantilevered concrete beam segment for suspending and positioning the steel-concrete composite section. The prestressed steel strand pretensioning subsystem is located in the steel-concrete composite section area for applying pretension before concrete pouring. The embedded component subsystem is embedded in the cantilever end of the cantilevered concrete beam segment for welding to the steel-concrete composite section after it is in place. The prestressed steel strand pretensioning subsystem is located in the steel-concrete composite section area for applying pretension before concrete pouring.

[0008] The gantry subsystem and the cantilever beam subsystem jointly bear and transmit the concrete pouring load; the gantry subsystem, as the front suspension body, cooperates with the cantilever beam subsystem, which is anchored to the top of the main beam at the rear end, to form a support structure in space, distributing the load to the stress-bearing parts of the cantilevered concrete beam segment.

[0009] Preferably, the gantry subsystem includes a gantry body, a hoisting steel strand, and a jack for driving the hoisting steel strand. A front upper crossbeam is fixed to the front end of the gantry body, and the jack is mounted on the front upper crossbeam. After the hoisting steel strand passes through the jack and the front upper crossbeam, it is connected to the top of the steel-concrete composite section through a lower lifting device.

[0010] Preferably, the main body of the hanger is modified from the hanging basket used for constructing the cantilevered concrete beam segment. There are two sets of the main body of the hanger, which are located on both sides of the web at the front end of the cantilevered concrete beam segment, and are connected to the front upper crossbeam through a connecting system to increase the overall stability.

[0011] Preferably, a jack base is provided at the top of the front upper crossbeam below the jack, and the lower part of the jack base is engaged with the upper flange of the front upper crossbeam and fixed by welding; a lifting device connecting seat is provided between the lifting device and the lifting steel strand, and the bottom of each set of lifting devices is connected to the top of the steel-concrete composite section through two first lifting lugs.

[0012] Preferably, the cantilever beam subsystem includes cantilever beams, which are made of high-strength steel, and there are four sets of cantilever beams arranged in the transverse direction of the bridge. One end of the cantilever beam is fixed to the top of the cantilevered concrete beam segment by cantilever beam embedded parts and rear anchors, and the other end extends above the steel-concrete composite segment.

[0013] Preferably, it also includes a suspension mechanism, wherein the upper part of the cantilever end of the cantilever beam is provided with a front suspension beam and a rear suspension beam in the longitudinal direction of the bridge; the suspension mechanism includes a suspension strap, which connects the front suspension beam, the rear suspension beam and a second lifting lug provided at the top of the steel-concrete composite section.

[0014] Preferably, the rear suspension beam has a through hole corresponding to the top plate of the steel-concrete composite section, and the suspension strap passes through the through hole vertically downward and connects to the longitudinal stiffening rib of the bottom plate of the steel-concrete composite section.

[0015] Preferably, the embedded component subsystem includes web embedded components and bottom plate embedded components; the web embedded components are embedded in the web on both sides of the cantilever end of the cantilevered concrete beam segment, and their sides are flush with the outer surface of the web; the bottom plate embedded components are embedded in the bottom of the bottom plate at the cantilever end of the cantilevered concrete beam segment, and their bottom surface is flush with the bottom surface of the bottom plate.

[0016] Preferably, the prestressed steel strand pretensioning system includes top slab prestressed steel strands and web prestressed steel strands; the top slab prestressed steel strands and web prestressed steel strands are short bundles arranged in the steel-concrete composite section area, and their positions are close to the web pre-embedded parts at the top of the web of the cantilevered concrete beam section. The number of tensioned strands and the pretension force are determined to be able to offset the tension generated on the upper web pre-embedded parts during concrete pouring and control the bending moment.

[0017] A construction method for a suspended support system for a steel-concrete composite section includes the following steps: When constructing the last segment of a cantilevered concrete beam, pre-embed components of the pre-embedded part subsystem and anchoring pre-embedded parts of the cantilever beam subsystem; use the gantry subsystem to hoist the steel-concrete composite section to the end of the cantilevered concrete beam section and perform precise elevation adjustment; weld and fix the positioned steel-concrete composite section to the pre-embedded part subsystem; tension the prestressed steel strand pre-tensioning subsystem and apply pre-tension force; install the cantilever beam subsystem and effectively connect it to the steel-concrete composite section through a hanging mechanism; and perform concrete pouring construction for the steel-concrete composite section.

[0018] The beneficial effects of this invention are as follows: (1) The cantilever beam subsystem and the embedded part subsystem work together to bear most of the weight of the concrete when the steel-concrete joint section is poured. The force is clear and the safety is high. It solves the problem that the steel-concrete interface is difficult to fit closely due to construction and processing errors when the steel-concrete joint section is in place during construction, resulting in the load transfer at the steel-concrete connection being entirely borne by the weld between the embedded part and the steel beam of the steel-concrete joint section.

[0019] (2) The application of the cantilever beam subsystem avoids the problem of reduced weld quality caused by high-altitude welding operations in the steel-concrete composite section, which brings safety hazards to the construction of the steel-concrete composite section.

[0020] (3) The pre-tensioning operation of the prestressed steel strand pre-tensioning subsystem before pouring largely offsets the tension of the embedded parts in the upper web of the steel-concrete composite section during concrete pouring and effectively controls the influence of bending moment on the embedded parts. Attached Figure Description

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic side view of the overall structure of the concrete pouring suspension support system provided in one embodiment of the present application; Figure 2 This is a side-view exploded structural diagram of a concrete pouring suspension support system provided in one embodiment of this application; Figure 3 This is a side view of the hanger subsystem of the concrete pouring suspension support system provided in one embodiment of the present application; Figure 4 This is a front view structural schematic diagram of the hanger subsystem in a concrete pouring suspension support system provided in one embodiment of the present application; Figure 5 This is a side view of the cantilever beam subsystem in a concrete pouring suspension support system provided in one embodiment of this application; Figure 6 This is a front view structural schematic diagram of the cantilever beam subsystem in a concrete pouring suspension support system provided in one embodiment of this application; Figure 7 This is a side structural schematic diagram of the prestressed steel strand pretensioning subsystem and embedded parts in a concrete pouring suspension support system provided in one embodiment of this application; Figure 8 This is a front structural schematic diagram of the prestressed steel strand pretensioning subsystem and embedded parts in a concrete pouring suspension support system provided in one embodiment of this application; Legend: 1. Hanger Subsystem; 101. Hanger Main Body; 102. Lifting Steel Strand; 103. Jack; 104. Jack Base; 105. Front Upper Crossbeam; 106. Lifting Tool Connector; 107. Lifting Tool; 108. First Lifting Lug; 2. Cantilever Beam Subsystem; 201. Cantilever Beam; 202. Cantilever Beam Embedded Part; 203. Rear Anchor; 204. Front Hanging Crossbeam; 205. Rear Hanging Crossbeam; 206. Lifting Straps; 207. Second Lifting Lug; 3. Embedded Parts Subsystem; 301. Web Embedded Part; 302. Bottom Plate Embedded Part; 4. Prestressed Steel Strand Pretensioning Subsystem; 401. Top Plate Prestressed Steel Strand; 402. Web Prestressed Steel Strand; 5. Steel-Concrete Composite Section; 6. Cantilevered Concrete Beam Section; 7. Concrete. Detailed Implementation

[0023] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0024] like Figures 1-8 As shown, a suspension support system for a steel-concrete composite section includes a hanger subsystem 1, a cantilever beam subsystem 2, an embedded component subsystem, and a prestressed steel strand pretensioning subsystem. The hanger subsystem 1 spans and is anchored to the front end of the constructed cantilevered concrete beam segment 6, used to suspend and position the steel-concrete composite section 5. The prestressed steel strand pretensioning subsystem 4 is arranged in the area of ​​the steel-concrete composite section 5, used to apply pretension before the concrete 7 is poured. The embedded component subsystem 3 is pre-embedded in the cantilever end of the cantilevered concrete beam segment 6, used to weld it to the steel-concrete composite section 5 after it is in place. The prestressed steel strand pretensioning subsystem 4 is arranged in the area of ​​the steel-concrete composite section 5, used to apply pretension before the concrete 7 is poured. Multiple subsystems form a stable support structure in space, distributing the concrete 7 pouring load to the stress-bearing parts of the cantilevered concrete beam segment 6, thereby controlling deformation and stress. The hanger subsystem 1, as the front-end load-bearing core, experiences a dynamic stress process. In the initial hoisting stage, it primarily bears the static load generated by the self-weight of the steel-concrete composite segment 5. When concrete 7 begins to be poured, the load increases linearly with the volume of concrete poured, and the bending moment and shear force borne by the hanger body 101 and the front upper crossbeam 105 increase accordingly. The jack 103 provides upward tension by tensioning the hoisting steel strands 102. This tension needs to be controlled to balance the constantly changing downward load and allows for fine-tuning to precisely control the elevation of the composite segment. The concentrated load is transformed into a controllable suspension force through the robust hanger structure, preventing initial deformation or damage caused by unstable support from the outset.

[0025] In one embodiment, the gantry subsystem 1 and the cantilever beam subsystem 2 jointly bear and transmit the concrete 7 pouring load. The gantry subsystem 1, as the front-end suspended main body, cooperates with the cantilever beam subsystem 2, which is anchored to the top of the main beam at the rear end, to form a supporting structure in space, distributing the load to the stress-bearing parts of the cantilevered concrete beam segment 6. The bridge web is the main stress-bearing component of the main beam, which can effectively transmit the load upward, downward, and to the supports. By directly applying the two sets of gantry to the web, the large load generated by the concrete 7 pouring can be directly transmitted to the core stress area of ​​the main beam through the gantry, avoiding local crushing or cracking that may be caused by the load acting on the weak top plate. The frame structure formed by the connecting system and the front upper crossbeam 105 effectively resists the horizontal force and torque generated by the incomplete asymmetry of the load on both sides or external factors (such as wind load, construction machinery off-center load).

[0026] The suspender subsystem 1 bears part of the load by suspending the steel-concrete composite section 5, while the cantilever beam subsystem 2 transfers the load to the top of the main beam through anchor points, thereby distributing and balancing the load. This improves the overall stability and load-bearing capacity of the support system, avoids local stress concentration, reduces the risk of deformation of the steel-concrete composite section 5 during construction, and thus extends the service life of the bridge expansion joint and reduces maintenance requirements.

[0027] In one embodiment, the gantry subsystem 1 includes a gantry body 101, a hoisting steel strand 102, and a jack 103 for driving the hoisting steel strand 102. A front upper crossbeam 105 is fixed to the front end of the gantry body 101, and the jack 103 is mounted on the front upper crossbeam 105. After the hoisting steel strand 102 passes through the jack 103 and the front upper crossbeam 105, it is connected to the top of the steel-concrete composite section 5 through the lower lifting device 107. The detailed design of the front upper crossbeam 105 and the jack 103 is directly related to the local stress safety. The jack 103 generates a huge concentrated load during tensioning. If it acts directly on the flange of the crossbeam, it may cause local buckling deformation of the flange plate. The jack base 104 with lower fastening and welding is set to change the point contact to the surface contact, effectively spreading the concentrated force to the entire cross section of the front upper crossbeam 105, which significantly improves the local bearing condition. Similarly, the setting of the lifting device connecting seat 106 and the two first lifting lugs 108 disperses the concentrated tension of the single steel strand into two lifting points acting on the top plate of the steel-concrete composite section 5, avoiding excessive local stress and deformation of the top plate.

[0028] In one embodiment, the main body 101 of the hanger is modified from the formwork of the cantilevered concrete beam segment 6. There are two sets of main bodies 101, located on the two sides of the web at the front end of the cantilevered concrete beam segment 6, and connected to the front upper crossbeam 105 through a connecting system to increase overall stability. By modifying the existing formwork structure, the fabrication and installation process of the hanger is simplified. The lateral stability is enhanced by the connecting system, and the original main truss load-bearing structure and spatial connection system of the formwork are retained to make full use of its mature stress system. At the same time, only the formwork system, slings and other components dedicated to concrete pouring are removed, which not only ensures that the main body 101 of the hanger has sufficient strength and rigidity, but also significantly saves the design, manufacturing and installation costs of the temporary support structure and greatly shortens the construction preparation cycle.

[0029] In one embodiment, a jack base 104 is provided at the top of the front upper crossbeam 105 below the jack 103. The lower part of the jack base 104 is engaged with the upper flange of the front upper crossbeam 105 and fixed by welding. A lifting device connecting seat 106 is provided between the lifting device 107 and the lifting steel strand 102. The bottom of each set of lifting devices 107 is connected to the top of the steel-concrete composite section 5 through two first lifting lugs 108, providing a stable support point for the jack base 104 and ensuring that the jack 103 will not slide or tilt during operation. The lifting device connecting seat 106 and the first lifting lugs 108 evenly distribute the load to achieve stable suspension of the steel-concrete composite section 5.

[0030] In one embodiment, the cantilever subsystem 2 includes cantilever beams 201, which are made of high-strength steel and are arranged in four sets along the transverse direction of the bridge. One end of the cantilever beam 201 is fixed to the top of the cantilever concrete beam segment 6 through cantilever beam embedded parts 202 and rear anchors 203, and the other end extends above the steel-concrete composite segment 5. The cantilever beam 201 utilizes the bending resistance of the high-strength steel to transfer the concrete 7 pouring load from the cantilever end to the anchor point and distribute it to the main beam structure. It has a strong load-bearing capacity, is simple and quick to install, and optimizes the load distribution through transverse bridge arrangement, reducing stress concentration in the steel-concrete composite segment 5.

[0031] In one embodiment, the upper part of the cantilever end of the cantilever beam 201 is provided with a front hanging crossbeam 204 and a rear hanging crossbeam 205 in the longitudinal direction of the bridge. The hanging mechanism includes a hanging strap 206, which connects the front hanging crossbeam 204, the rear hanging crossbeam 205 and the second lifting lug 207 set at the top of the steel-concrete composite section 5. One end is rigidly connected to the solidified main beam concrete 7 through the embedded part and the rear anchor 203 fixing system (fixed end), and the other end is freely cantilevered. When bearing the load transmitted from the steel-concrete composite section 5, the root of the cantilever beam 201 bears the maximum bending moment and shear force. High-strength steel is used to provide sufficient bending and shear strength. The four sets of cantilever beams 201 arranged in the transverse direction of the bridge can effectively disperse the concentrated load in the longitudinal direction of the bridge along the transverse direction and prevent the top plate of the main beam from bending laterally.

[0032] In one embodiment, the rear suspension beam 205 has a through hole corresponding to the top plate of the steel-concrete composite section 5. The suspension strap 206 passes through the through hole and descends vertically downward, connecting with the longitudinal stiffening rib of the bottom plate of the steel-concrete composite section 5. The steel-concrete composite section 5 is connected to the cantilever end of the cantilever beam 201 through the suspension strap 206, forming a multi-point suspension. The through hole ensures that the suspension strap is subjected to vertical force, reduces eccentric load, improves the uniformity and stability of the suspension, and prevents the steel-concrete composite section 5 from tilting or shaking during the pouring process, thereby reducing the risk of deformation and damage.

[0033] In one embodiment, the embedded part subsystem 3 includes a web embedded part 301 and a bottom plate embedded part 302. The web embedded part 301 is embedded in the web on both sides of the cantilever end of the cantilevered concrete beam segment 6, and its side is flush with the outer surface of the web. The bottom plate embedded part 302 is embedded in the bottom of the bottom plate at the cantilever end of the cantilevered concrete beam segment 6, and its bottom surface is flush with the bottom surface of the bottom plate. The web embedded part 301 and the bottom plate embedded part 302 are welded to the steel-concrete joint section 5 after it is in place. The stress state changes from the stress-free state at the time of embedding to the complex stress state at the service stage. The web embedded part 301 mainly bears the bending moment and shear force transmitted from the joint section, while the bottom plate embedded part 302 mainly bears the vertical pressure and possible pull-out force. The outer surface is flush with the surface of the concrete 7, which ensures the convenience of welding operation and the reliability of weld quality.

[0034] In one embodiment, the prestressed steel strand pretensioning subsystem 4 includes a top slab prestressed steel strand 401 and a web prestressed steel strand 402. The top slab prestressed steel strand 401 and the web prestressed steel strand 402 are short strands arranged in the region of the steel-concrete composite section 5. Their positions are close to the web pre-embedded parts 301 at the top of the web of the cantilevered concrete beam section 6. The number of tensioned strands and the pretension force are designed to counteract the tension generated on the upper web pre-embedded parts 301 during the pouring of concrete 7 and to control the bending moment. Before pouring concrete 7, pre-tensioning force is applied to the short steel strands arranged in the top slab and web. This force will establish pre-existing compressive stress inside the steel structure of the steel-concrete composite section 5. When concrete 7 is poured, its wet weight and flow pressure will generate tensile stress on the structure, especially the upper area. The pre-applied compressive stress can effectively offset this tensile stress, thereby significantly reducing the risk of cracking in the weld area of ​​the embedded part 301 in the upper web during the construction stage. By actively applying prestress to resist and balance the adverse internal forces caused by external loads, the tensile stress in the weakest link of the structure during construction is controlled within a safe range, which greatly improves the safety and structural forming quality during the construction stage and reduces maintenance problems caused by the expansion of initial cracks in the later stage.

[0035] A construction method for a suspended support system for a steel-concrete composite section includes the following steps: During the construction of the last segment of the cantilevered concrete beam segment 6, components of the embedded parts subsystem 3 and anchoring embedded parts of the cantilever beam subsystem 2 are simultaneously pre-embedded to lay the interface foundation for subsequent construction. Subsequently, the hanging basket used for cantilever construction is modified, retaining its main load-bearing structure to form the hanging frame subsystem 1. This system is then used to hoist the steel-concrete composite section 5 to the designed position, completing preliminary positioning and precise adjustment of its three-dimensional spatial coordinates. After the steel-concrete composite section 5 is in place, it is immediately welded to the embedded parts subsystem 3 pre-embedded at the end of the cantilevered beam segment, achieving a rigid connection between the old and new structures and forming a preliminary force transmission path.

[0036] Following the principle of "strengthening connections first, then distributing loads": after completing the aforementioned welding connections, the main load-bearing cantilever beam 201 is not immediately installed. Instead, the prestressed steel strands arranged in the steel-concrete composite section 5 are first tensioned. The purpose of this process is to actively establish favorable pre-stress within the structure, particularly enhancing the resistance to tensile stress in the connection area between the upper part of the composite section and the embedded part 301 in the web, thus forming an actively strengthened whole with preliminary bending stiffness. Based on this enhanced stability, the cantilever beam subsystem 2 is then installed and reliably connected to the steel-concrete composite section 5 via a suspension mechanism. At this point, the front-end suspended scaffold subsystem 1 and the rear-end anchored cantilever beam subsystem 2 together form a spatial three-dimensional support network, working in conjunction with the pre-strengthened structural body to safely and disperse most of the load generated by the subsequent concrete 7 pouring to the already formed main beam structure. Finally, under this multi-layered, clearly defined stable system, concrete 7 is poured, achieving a smooth and safe transition from the steel structure to the reinforced concrete 7 structure. This method standardizes complex construction processes through phased, actively controlled, and sequential operations, significantly improving operational safety, installation accuracy, and system reliability.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A suspension support system for a steel-concrete composite section, characterized in that, The system includes a scaffolding subsystem, a cantilever beam subsystem, an embedded component subsystem, and a prestressed steel strand pretensioning subsystem. The scaffolding subsystem spans and is anchored to the front end of the constructed cantilevered concrete beam segment, used to suspend and position the steel-concrete composite segment. The prestressed steel strand pretensioning subsystem is located in the steel-concrete composite segment area, used to apply pretension before concrete pouring. The embedded component subsystem is pre-embedded in the cantilever end of the cantilevered concrete beam segment, used to weld it to the steel-concrete composite segment after it is in place. The prestressed steel strand pretensioning subsystem is located in the steel-concrete composite segment area, used to apply pretension before concrete pouring. The gantry subsystem and the cantilever beam subsystem jointly bear and transmit the concrete pouring load; the gantry subsystem, as the front suspension body, cooperates with the cantilever beam subsystem, which is anchored to the top of the main beam at the rear end, to form a support structure in space, distributing the load to the stress-bearing parts of the cantilevered concrete beam segment.

2. The suspension support system for a steel-concrete composite section according to claim 1, characterized in that, The gantry subsystem includes a gantry body, a hoisting steel strand, and a jack for driving the hoisting steel strand. A front upper crossbeam is fixed to the front end of the gantry body, and the jack is mounted on the front upper crossbeam. After the hoisting steel strand passes through the jack and the front upper crossbeam, it is connected to the top of the steel-concrete composite section through a lower lifting device.

3. The suspension support system for a steel-concrete composite section according to claim 2, characterized in that, The main body of the hanger is modified from the hanging basket used for constructing the cantilevered concrete beam segment. There are two sets of the main body of the hanger, which are located on both sides of the web at the front end of the cantilevered concrete beam segment, and are connected to the front upper crossbeam through a connecting system to increase the overall stability.

4. The suspension support system for a steel-concrete composite section according to claim 3, characterized in that, The top of the front upper crossbeam is provided with a jack base below the jack. The lower part of the jack base is engaged with the upper flange of the front upper crossbeam and fixed by welding. A lifting device connecting seat is provided between the lifting device and the lifting steel strand, and the bottom of each lifting device is connected to the top of the steel-concrete composite section through two first lifting lugs.

5. The suspension support system for a steel-concrete composite section according to claim 2, characterized in that, The cantilever beam subsystem includes cantilever beams, which are made of high-strength steel and consist of four sets arranged in the transverse direction of the bridge. One end of the cantilever beam is fixed to the top of the cantilevered concrete beam segment through cantilever beam embedded parts and rear anchors, and the other end extends above the steel-concrete composite segment.

6. The suspension support system for a steel-concrete composite section according to claim 1, characterized in that, It also includes a suspension mechanism, wherein the upper part of the cantilever end of the cantilever beam is provided with a front suspension beam and a rear suspension beam in the longitudinal direction of the bridge; the suspension mechanism includes a suspension strap, which connects the front suspension beam, the rear suspension beam and a second lifting lug set at the top of the steel-concrete composite section.

7. The suspension support system for a steel-concrete composite section according to claim 6, characterized in that, The rear suspension beam has a through hole corresponding to the top plate of the steel-concrete composite section. The suspension strap passes through the through hole and descends vertically downwards, connecting with the longitudinal stiffening rib of the bottom plate of the steel-concrete composite section.

8. The suspension support system for a steel-concrete composite section according to claim 1, characterized in that, The embedded component subsystem includes web embedded components and bottom plate embedded components; the web embedded components are embedded in the web on both sides of the cantilever end of the cantilevered concrete beam segment, and their sides are flush with the outer surface of the web; the bottom plate embedded components are embedded in the bottom of the bottom plate at the cantilever end of the cantilevered concrete beam segment, and their bottom surface is flush with the bottom surface of the bottom plate.

9. The suspension support system for a steel-concrete composite section according to claim 1, characterized in that, The prestressed steel strand prestressing subsystem includes top slab prestressed steel strands and web prestressed steel strands; the top slab prestressed steel strands and web prestressed steel strands are short bundles arranged in the steel-concrete composite section area, and their positions are near the web pre-embedded parts at the top of the web of the cantilevered concrete beam section. The number of tensioned strands and the prestressing force are determined to be able to offset the tensile force generated on the upper web pre-embedded parts during concrete pouring and control the bending moment.

10. A construction method for a suspension support system for a steel-concrete composite section, applied to the suspension support system for a steel-concrete composite section as described in any one of claims 1-9, characterized in that, The process includes the following steps: When constructing the last segment of the cantilevered concrete beam, pre-embed components of the pre-embedded part subsystem and anchoring pre-embedded parts of the cantilever beam subsystem; use the gantry subsystem to hoist the steel-concrete composite section to the end of the cantilevered concrete beam segment and perform precise elevation adjustment; weld and fix the positioned steel-concrete composite section to the pre-embedded part subsystem; tension the prestressed steel strand pre-tensioning subsystem and apply pre-tension force; install the cantilever beam subsystem and effectively connect it to the steel-concrete composite section through a hanging mechanism; and perform concrete pouring for the steel-concrete composite section.

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