Large-span long-association rail-cum-road continuous steel truss girder large-tonnage support post-installation construction method

Abstract

The application relates to a large-span long-connection highway-railway combined continuous steel truss beam large-tonnage support post-installation construction method, which comprises the following steps: installing temporary supports; erecting a steel truss beam and a highway bridge deck; respectively lifting the steel beams at the top of each pier, constructing a wet joint in the negative bending moment area of the top of the pier, tensioning horizontal and vertical prestress, lowering the beam, and folding each steel truss beam to install the steel truss beams into an integrated continuous steel truss beam; installing a slide corresponding to the position of the middle truss of the steel truss bridge, lifting the integrated continuous steel truss beam; removing the temporary supports, installing formal supports, and pouring grouting into the formal supports; curing the completed formal supports, and lowering the integrated continuous steel truss beam onto the formal supports after the curing is completed. According to the application, the temporary supports are first installed, then the steel truss beams are assembled, and finally the steel truss beams are lifted and assembled; the formal supports are installed through the slide, the technical problem of the difficulty in installing the formal supports in a narrow construction space is effectively solved, and the installation precision and quality of the formal supports are ensured.

Description

Technical Field

[0001] This application relates to the field of bridge construction technology, and in particular to a method for the post-installation of large-tonnage supports for long-span, long-connection, dual-purpose (road and rail) continuous steel truss girders. Background Technology

[0002] The innovative structures, heavy tonnage, extended spans, and increased number of connections in bridge construction place increasingly higher demands on the safety, quality, and schedule of bridge bearing installation. During bearing installation, special protection is required for the finished bearings during the subsequent steel beam lifting and lowering processes to prevent damage to the bearing components, increasing installation costs and extending the construction period. When non-standard or specially designed bearings are supplied by the client, mismatches between the client's supply schedule and the steel beam erection schedule can lead to significant losses in manpower, materials, financial resources, and time. Summary of the Invention

[0003] This application provides a method for the post-installation of large-tonnage supports for long-span, long-connection, dual-purpose (railway and highway) continuous steel truss girders, in order to solve the technical problems in related technologies where it is difficult to install large-tonnage supports in confined construction spaces, and where the installation accuracy and quality are not high.

[0004] This application provides a method for the post-installation construction of large-tonnage supports for long-span, long-connection, dual-purpose (road and rail) continuous steel truss girders, including the following steps:

[0005] Step S1: Install temporary supports on the bridge deck support pads;

[0006] Step S2: Erect steel truss beams and highway bridge deck on the bridge deck, lift the steel beams at the top of each pier, construct the wet joints in the negative bending moment zone at the top of the pier, tension the transverse and longitudinal prestress, lower the beams, and assemble the steel truss beams into a continuous steel truss beam.

[0007] Step S3: Install the slide rail at the corresponding position of the middle truss of the steel truss bridge, lift the entire continuous steel truss beam, and carry out wet joint construction and tensioning of transverse and longitudinal prestressing within the left and right half spans of the pier top.

[0008] Step S4: Remove the temporary support, install the permanent support on the bridge deck support pad, and grout into the permanent support.

[0009] Step S5: After the grouting is completed, the entire continuous steel truss beam is lowered to the top of the formal support and then tightened.

[0010] In some embodiments, the step "Step S2, erecting steel truss girders and highway bridge decks on the bridge deck, jacking up the steel beams at the top of each pier, constructing wet joints in the negative bending moment zone at the top of the piers, tensioning transverse and longitudinal prestressing, lowering the beams, and assembling the steel truss girders into a continuous steel truss girder" specifically includes the following steps:

[0011] Steel trusses and highway bridge decks were erected on the bridge surface;

[0012] From both ends of the bridge deck toward the center, the steel truss girder is lifted and the wet joint of the negative bending moment zone at the top of the pier is constructed. After the wet joint is completed, the steel truss girder is tensioned and subjected to longitudinal and transverse prestressing.

[0013] The steel truss beams at the top of each pier were lowered and assembled into a continuous steel truss beam.

[0014] In some embodiments, the step "step S3, installing the sliding track at the corresponding position of the middle truss of the steel truss bridge, lifting the entire continuous steel truss beam, and constructing the wet joints and tensioning of transverse and longitudinal prestressing within the left and right half-span ranges of the pier top" specifically includes the following steps:

[0015] Install sliding rails at the corresponding positions of the middle truss of the steel truss bridge;

[0016] The jacks are used to lift the truss synchronously. After each synchronous lifting, the top of the temporary support is compacted with steel plates. Then the jacks are returned to oil and the truss is lifted synchronously again. This process is repeated to lift the entire continuous steel truss to the design position.

[0017] Wet joints and tensioning of transverse and longitudinal prestressing were carried out within the left and right half spans of the pier top.

[0018] In some embodiments, the permanent support includes an upstream support, a middle girder support, and a downstream support. The step "Step S4: Remove the temporary support, install the permanent support on the bridge deck support pad, and grout into the permanent support" specifically includes the following steps:

[0019] Once the entire continuous steel truss girder has been lifted to the preset height, the temporary supports are removed.

[0020] The middle truss support was hoisted onto the bridge and moved to the slideway via the upstream support pad stone for temporary storage.

[0021] First, install the upstream side support, then slide the middle truss support to the middle truss position via the slide rail for installation, and finally install the downstream side support.

[0022] Grouting is performed into the formal support.

[0023] In some embodiments, the step of "grouting into the permanent support" specifically includes the following steps:

[0024] Steel formwork was laid above the formal supports;

[0025] Grouting is performed between the steel formwork and the supporting pad stones;

[0026] After grouting is completed, the steel formwork is removed.

[0027] In some embodiments, the step of "laying steel formwork above the formal support" specifically includes the following steps:

[0028] Roughen the surface of the support pad stone at the location of the permanent support, remove debris from the reserved bolt holes, and lay steel formwork on top of the support pad stone and the permanent support.

[0029] In some embodiments, the following steps are included before the step of "grouting between the steel formwork and the support pad":

[0030] Insert sponge strips into the bottom of the steel formwork;

[0031] A layer of rubber leak-proof strip is fixed on the top surface of the supporting pad stone.

[0032] In some embodiments, the step "Step S5, after the grouting of the formal support is completed, the entire continuous steel truss beam is lowered to the top of the formal support and fastened" specifically includes the following steps:

[0033] Cover the top surface of the formal support after grouting with burlap sacks or straw mats, and spray water for curing after the grout mortar has set.

[0034] After maintenance, the entire continuous steel truss girder is lowered to the top of the formal support, and the steel girder and the formal support are then fastened together.

[0035] The beneficial effects of the technical solution provided in this application include: The embodiments of this application provide a method for the post-installation construction of large-tonnage supports for long-span, long-connection, dual-purpose (railway and highway) continuous steel truss girders. By first installing temporary supports, then assembling the steel truss girders, and finally lifting the assembled steel truss girders and installing the permanent supports through a sliding track, the technical problem of difficult installation of permanent supports in a narrow construction space is effectively solved, and the installation accuracy and quality of the permanent supports are improved. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A flowchart illustrating the method for post-installation construction of large-tonnage supports for long-span, multi-purpose (road and rail) continuous steel truss girders provided in this application embodiment;

[0038] Figure 2 This is a schematic diagram illustrating a construction scenario where a steel truss girder is lifted using jacks on the pier top, as provided in an embodiment of this application.

[0039] Figure 3This is a schematic diagram of a construction scenario for dismantling temporary supports, provided in an embodiment of this application.

[0040] Figure 4 This is a schematic diagram of the installation scenario for the formal support provided in the embodiments of this application;

[0041] Figure 5 This is a schematic diagram of the construction scenario from beam lowering to formal support provided in an embodiment of this application;

[0042] Figure 6 The main channel continuous steel truss bridge span layout diagram provided for the embodiments of this application;

[0043] Figure 7 This is an internal view of the formal support installation slide provided in the embodiments of this application;

[0044] Figure 8 This is a schematic diagram of the installation of the middle truss support provided in an embodiment of this application.

[0045] In the diagram: 1. Support pad; 2. Jack; 3. Temporary support; 4. Permanent support. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] This application provides a method for the post-installation of large-tonnage supports for long-span, long-connection, dual-purpose (railway and highway) steel truss girders. This method can solve the technical problems of difficulty in installing large-tonnage supports in confined construction spaces, as well as the low installation accuracy and quality.

[0048] Please refer to Figure 1 This application provides a method for the post-installation construction of large-tonnage supports for long-span, long-connection, dual-purpose (road and rail) steel truss girders, including the following steps:

[0049] Step S1: Install temporary supports 3 on the bridge deck support pad 1 to provide temporary support for the steel truss beams that are not precisely welded.

[0050] Step S2: Erect steel truss beams on the bridge deck, lay highway bridge deck panels on top of temporary supports 3 and bridge deck support pads 1, lift the steel beams at the top of each pier, construct wet joints in the negative bending moment zone at the top of the pier, tension the transverse and longitudinal prestresses, perform preliminary welding and debugging, lower the beams, and assemble the steel truss beams into a continuous steel truss beam.

[0051] Step S3: Install the slide rail at the corresponding position of the middle truss of the steel truss bridge, lift the entire continuous steel truss beam, and carry out wet joint construction and tensioning of transverse and longitudinal prestressing within the left and right half spans of the pier top.

[0052] Step S4: Remove the temporary support 3, install the permanent support 4 on the bridge deck support pad 1, and grout into the permanent support 4 to improve the stability of the connection between the permanent support 4 and the bridge deck support pad 1.

[0053] Step S5: After the grouting of the formal support 4 is completed, the entire continuous steel truss beam is lowered to the top of the formal support 4 and then tightened.

[0054] This application provides a method for the post-installation construction of large-tonnage supports for long-span, long-connection, dual-purpose (railway and highway) continuous steel truss girders. By first installing temporary supports 3, then assembling and adjusting the steel truss girders to meet construction requirements, and finally lifting the assembled steel truss girders, the permanent supports 4 are installed via a sliding track. This method effectively solves the technical problem of difficult installation of permanent supports 4 in confined construction spaces and improves the installation accuracy and quality of permanent supports 4.

[0055] In one embodiment, the step S2, "erecting steel truss beams and highway bridge decks on the bridge deck, jacking up the steel beams at the top of each pier, constructing wet joints in the negative bending moment zone at the top of the piers, tensioning transverse and longitudinal prestressing, lowering the beams, and assembling the steel truss beams into a continuous steel truss beam," specifically includes the following steps:

[0056] Steel truss beams are erected on the bridge deck, and highway bridge deck panels are laid on the bridge deck support pads 1 and temporary supports 3.

[0057] From both ends of the bridge deck toward the center, the steel truss girder is lifted and the wet joint of the negative bending moment zone at the top of the pier is constructed. After the wet joint is completed, the steel truss girder is tensioned and subjected to longitudinal and transverse prestressing.

[0058] The steel truss beams at the top of each pier were lowered and assembled into a continuous steel truss beam.

[0059] In a more specific embodiment, please refer to Figure 1 and Figure 5 The bridge design has 9 sets of piers, numbered 0#-8#. The steps described as "lifting the steel truss girder from both ends of the bridge deck towards the center, constructing the wet joints in the negative bending moment zone of the pier tops, and then performing transverse and longitudinal prestressing construction on the steel truss girder in the negative bending moment zone after the wet joints are completed" specifically include the following steps:

[0060] After the steel beams and highway bridge deck were erected and installed, the following steps were taken: First, the top of pier #1 / 7 was lifted, the wet joint in the negative bending moment zone of the pier top was constructed, and the transverse and longitudinal prestressing was applied. Then, the beam was lowered from the top of pier #1 / 7. Next, the top of pier #2 / 6 was lifted, the wet joint in the negative bending moment zone of the pier top was constructed, and the transverse and longitudinal prestressing was applied. Then, the beam was lowered from the top of pier #2 / 6. The next step was to lift the top of pier #3 / 5, the wet joint in the negative bending moment zone of the pier top was constructed, and the transverse and longitudinal prestressing was applied. Then, the beam was lowered from the top of pier #3 / 5. Finally, the top of pier #4 was lifted, the wet joint in the negative bending moment zone of the pier top was constructed, and the transverse and longitudinal prestressing was applied. Then, the beam was lowered from the top of pier #4.

[0061] In one embodiment, the step "Step S3, installing the sliding track at the corresponding position of the middle truss of the steel truss bridge, lifting the entire continuous steel truss beam, and constructing the wet joints and tensioning of transverse and longitudinal prestressing within the left and right half-span ranges of the pier top" specifically includes the following steps:

[0062] Install sliding rails at the corresponding positions of the middle truss of the steel truss bridge;

[0063] The jacks 2 are used to lift the truss synchronously. After each synchronous lifting, the top of the temporary support 3 is compacted with steel plates. Then, the jacks 2 are returned to oil and the truss is lifted synchronously again. This cycle is repeated to lift the entire continuous steel truss to the design position.

[0064] The wet joints and longitudinal and transverse prestressing construction within the left and right half-span ranges of the pier top were completed, and the final steel truss girder welding and assembly were finished.

[0065] In one embodiment, after the step of "constructing wet joints and tensioning transverse and longitudinal prestressing within the left and right half-spans of the pier top, and completing the final steel truss girder welding and assembly" is completed, the following steps are also included:

[0066] After the wet joints and tensioning work are completed within the left and right half-spans of the pier top, the steel beam lowering construction can proceed. Lowering the steel beam is the reverse process of lifting it. During lowering, jack 2 must be used to maintain synchronous and uniform pressure release. As the piston of jack 2 falls, the supporting steel beam must be promptly removed, leaving a gap between the support and the steel beam. Do not remove the supporting steel plate completely at once. For this steel beam lowering, provisions will be made for height fine-tuning supports and support grouting.

[0067] The lifting height is approximately (until the temporary support blocks for the steel beam can be removed). First, lift the upstream side truss. After removing temporary support 3, refer to... Figure 2 , Figure 8 As shown, after the middle truss support is hoisted onto the bridge and moved to the slideway for temporary storage via the upstream side support pad 1, the upstream side support is installed, followed by the middle truss support, and finally the downstream side support.

[0068] There must be no gaps at the bottom and sides of the slide and the contact points with the piers; the contact points between the sides of the slide and the supporting pad stone 1 must be smooth and transitional.

[0069] Table of Pier Bearing Models

[0070] Pier #0 TJQZ-G(GL)-17500-DX TJQZ-G(GL)-75000-HX TJQZ-G(GL)-17500-DX Pier #1 TJQZ-G(GL)-25000-ZX TJQZ-G(GL)-95000-ZX TJQZ-G(GL)-25000-ZX Pier #2 TJQZ-G(GL)-75000-DX TJQZ-G(GL)-95000-ZX TJQZ-G(GL)-75000-DX Pier #3 TJQZ-G(GL)-75000-DX TJQZ-G(GL)-95000-ZX TJQZ-G(GL)-75000-DX Pier #4 TJQZ-G(GL)-75000-DX TJQZ-G(GL)-95000-GD TJQZ-G(GL)-75000-DX Pier #5 TJQZ-G(GL)-75000-DX TJQZ-G(GL)-95000-ZX TJQZ-G(GL)-75000-DX Pier #6 TJQZ-G(GL)-75000-DX TJQZ-G(GL)-95000-ZX TJQZ-G(GL)-75000-DX Pier #7 TJQZ-G(GL)-25000-ZX TJQZ-G(GL)-95000-ZX JQZ-G(GL)-25000-ZX Pier #8 TJQZ-G(GL)-17500-DX TJQZ-G(GL)-75000-HX TJQZ-G(GL)-17500-DX

[0071] In one embodiment, before the step of "synchronously lifting the jacks 2, and after each synchronous lifting, compacting the top of the temporary support 3 with steel plates, then returning the jacks 2 to their original position and lifting synchronously again, repeating this cycle to lift the entire continuous steel truss to the design position," the following steps are also included:

[0072] Multiple measurements were taken of the steel beam's alignment at different temperatures to understand the construction status, elevation, mileage, and axis deviation of the steel beam. These measurements were then compared with the designed alignment to analyze and obtain the linear changes of the steel beam under different temperatures. This analysis provides a basis for the high-quality and high-precision installation of the final support 4 later on. Figure 1 and Figure 5 As shown, the self-weight of the continuous steel truss girder and highway bridge deck results in a force of 9778t at the top of pier #1. The force is distributed between the middle truss and the side trusses in a ratio of 0.3:0.4:0.3, resulting in a force of 3911t on the middle truss and 2933t on the side trusses of pier #1. Jack 2 for pier #1 is sufficient for lifting. The corresponding lifting stress for the middle truss of jack 2 is 24.44MPa, and for the side trusses, it is 18.33MPa. After all procedures are completed, jack 2 is used for synchronous lifting, with each lift not exceeding the calculated height. After each lift, steel plates are used to compact the top of the support on both sides before jack 2 is returned to its original position. This process is repeated until the steel beam is lifted to the designed position. The linearity of the steel beam is monitored during the lifting process; any deviations must be adjusted promptly.

[0073] Stress table at the top of the steel beam pier

[0074] 1 0# 2102 2 1# 9778 3 2# 6484 4 3# 8155 5 4# 11142

[0075] In one embodiment, the formal support 4 includes an upstream support, a middle girder support, and a downstream support. For more specific details, please refer to [reference needed]. Figure 6 The (112+6×168+112)m continuous steel truss girder adopts a large-adjustment friction pendulum seismic isolation spherical bearing. The design vertical bearing capacity is divided into four types: 95000KN, 75000KN, 25000KN, and 17500KN. The design longitudinal displacement is 0~±400mm, and the lateral displacement is 0~±15mm. The central truss of pier #4 is a fixed bearing, while the others are movable bearings. The main problem to be solved in this application is the installation of the central truss bearing in a confined construction space. The step "Step S4, removing the temporary bearing 3, installing the permanent bearing 4 on the bridge deck support pad 1, and grouting into the permanent bearing 4" specifically includes the following steps:

[0076] When the entire continuous steel truss girder is lifted to the preset height, remove temporary support 3, construct the wet joint of each half span on the top of the pier, and leave the reserved shear nail slots for the side truss unpoured; when the concrete strength reaches 100% and the curing period is not less than the number of days required by the specification, tension the transverse post-tensioned prestressing tendons in this area, and pour the concrete in the reserved shear nail slots of the side truss in this area after transverse tensioning; when the concrete strength reaches 100% and the curing period is not less than the number of days required by the specification, tension the longitudinal post-tensioned prestressing tendons in this area, and finally perform prestressed anchor sealing;

[0077] The middle truss support was hoisted onto the bridge and moved to the slideway via the upstream support pad stone 1 for temporary storage.

[0078] First, install the upstream side support, then slide the middle truss support to the middle truss position via the slide rail for installation, and finally install the downstream side support.

[0079] Grouting is poured into the formal support 4 to form a stable bridge support structure.

[0080] In one embodiment, the installation requirements for the supports in the process of "first installing the upstream side support, then sliding the middle truss support to the middle truss position via the slide rail for installation, and finally installing the downstream side support" are as follows:

[0081] (1) The installation of bearings should be based on the design mileage and the span distance of each pier of the steel beam to determine the center mileage of the bearings along the bridge direction. First, the bearings along the bridge direction should be aligned. During installation, attention should be paid to the bearing direction.

[0082] (2) When installing the support along the bridge direction, the upper and lower swing contact parts should be tightly fitted. The gap where they are not tightly fitted should not exceed the specifications and design requirements. The front and rear lateral gaps between the upper swing groove and the top of the lower swing along the bridge direction should be uniform, and the allowable deviation should be within the specifications.

[0083] (3) After the bearing is positioned along the bridge direction, the installation of the base plate of the movable bearing should be carried out according to the design documents and in conjunction with the measured beam span, with the temperature of the steel beam as the standard. When the construction temperature is different from the design temperature, calculations should be performed according to the data provided in the design drawings to determine the installation position of the base plate. The moving parts of the bearing should be cleaned to prevent dust, and it is strictly forbidden to damage or contaminate them. The sliding surface should be coated with silicone grease. The silicone grease filling should be full and free of air holes.

[0084] In one embodiment, the step of "grouting into the formal support 4" specifically includes the following steps:

[0085] Steel formwork should be laid above the formal support 4. The steel formwork should be installed flat, straight and tightly to prevent grout leakage.

[0086] Gravity grouting method is used to grout between the steel formwork and the supporting pad 1. Before grouting, the volume of grout should be estimated, sufficient material should be prepared, the height of the grouting port should ensure that the grout is dense, and the actual volume of grouting should not have too large an error with the calculated value. Grouting should be prevented from being missing in the middle. When grouting, the pre-reserved bolt holes of the support should be grouted first. When the pre-reserved holes of the support are almost full, grouting should be carried out from the center of the support to the periphery until the grout material is completely filled from the periphery of the steel formwork and the support base plate. The performance of the grouting material should meet the requirements of "Spherical Bearings for Railway Bridges" TB / T3320-2013.

[0087] After grouting is completed, remove the steel formwork, check for leaks, and repair any leaks if necessary. Remove the connecting plates and bolts of each support, repair any damaged paint on the supports, and install the support enclosure to complete the support installation.

[0088] In one embodiment, the step of "laying steel formwork above the formal support 4" specifically includes the following steps:

[0089] Roughen the surface of the support pad 1 at the location of the formal support 4, remove debris from the reserved bolt holes, lay steel templates on top of the support pad 1 and the formal support 4, wet the surface of the support pad 1 with water, and remove water from the reserved bolt holes.

[0090] In one embodiment, prior to the step of "grouting between the steel formwork and the support pad 1", the following steps are also included:

[0091] Insert sponge strips into the bottom of the steel formwork;

[0092] A layer of rubber leak-proof strip is fixed on the top surface of the support pad stone 1 and fixed to the top surface of the support pad stone 1 with expansion bolts;

[0093] The elevation of the four corners of the support is adjusted using pads. After the support is adjusted and in place, a gap should be left between the bottom surface of the lower support plate and the top surface of the support pad 1 to allow for the injection of non-shrink high-strength grouting material.

[0094] In one embodiment, the step "Step S5, after the grouting of the formal support 4 is completed, the entire continuous steel truss beam is lowered to the top of the formal support 4 and fastened" specifically includes the following steps:

[0095] Cover the top surface of the formal support 4 after grouting with burlap sacks or straw mats, and spray water for curing after the grout mortar has set.

[0096] After the grouting and curing of the support is completed and the strength meets the design requirements, the entire continuous steel truss beam is lowered to the top of the formal support 4, and the steel beam and the formal support 4 are fastened together with connecting bolts.

[0097] The technical principle of this invention is as follows: During the support installation process, the single-span steel truss beam at the top of the pier weighs approximately 1531 tons, which is a large weight. The lifting of the jack 2 is a key step in this construction process. In order to ensure the safety of the lifting and shorten the support time of the jack 2, considering that the lifting height is not large, the temporary support 3 can be pulled out by dragging the steel beam. This process is carried out by lifting the single truss. First, the upstream side truss is lifted. After the temporary support 3 is removed, the middle truss support is hoisted onto the bridge and moved to the slide by the upstream side support pad 1 for temporary storage. Then, the upstream side support is installed, followed by the middle truss support, and finally the downstream side support.

[0098] The construction scheme features a unique construction method: the installation of non-starting pier supports utilizes on-site modified materials for the sliding tracks, reducing costs. The central truss support is temporarily hoisted onto the high-speed railway side truss support pad 1 using a crane, and then slid onto the central truss for installation via the sliding tracks, overcoming difficulties such as installation challenges, limited operating space, and heavy support weight. The side truss supports are installed directly using a crane. The use of sliding tracks not only effectively reduces the installation difficulty of the central truss support but also shortens the construction period. Furthermore, the project quality and construction safety are at a high level, resulting in significant economic and social benefits.

[0099] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0100] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0101] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for the post-installation construction of large-tonnage supports for long-span, multi-purpose (road and rail) continuous steel truss girders, characterized in that, Includes the following steps: Step S1: Install temporary supports on the bridge deck support pads; Step S2: Erect steel truss beams and highway bridge deck on the bridge deck, lift the steel beams at the top of each pier, construct the wet joints in the negative bending moment zone at the top of the pier, tension the transverse and longitudinal prestress, lower the beams, and assemble the steel truss beams into a continuous steel truss beam. Step S3: Install the slide rail at the corresponding position of the middle truss of the steel truss bridge, lift the entire continuous steel truss beam, and carry out wet joint construction and tensioning of transverse and longitudinal prestressing within the left and right half spans of the pier top. Step S4: Remove the temporary support, install the permanent support on the bridge deck support pad, and grout into the permanent support; the permanent support includes an upstream side support, a middle girder support, and a downstream side support; the slide is used to slide the middle girder support to the middle girder position for installation. Step S5: After the grouting is completed, the entire continuous steel truss beam is lowered to the top of the formal support and then tightened.

2. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (highway and railway) continuous steel truss girders as described in claim 1, characterized in that, The steps described in "Step S2, erecting steel truss girders and highway bridge decks on the bridge deck, lifting the steel beams at the top of each pier, constructing wet joints in the negative bending moment zone at the top of the piers, tensioning transverse and longitudinal prestressing, lowering the beams, and assembling the steel truss girders into a continuous steel truss girder" specifically include the following steps: Steel trusses and highway bridge decks were erected on the bridge surface; From both ends of the bridge deck toward the center, the steel truss girder is lifted and the wet joint of the negative bending moment zone at the top of the pier is constructed. After the wet joint is completed, the steel truss girder is tensioned and subjected to longitudinal and transverse prestressing. The steel truss beams at the top of each pier were lowered and assembled into a continuous steel truss beam.

3. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (road and rail) continuous steel truss girders as described in claim 1, characterized in that... The step S3, "Installing the sliding track at the corresponding position of the middle truss of the steel truss bridge, lifting the entire continuous steel truss beam, and constructing the wet joints and tensioning of transverse and longitudinal prestressing within the left and right half-span ranges of the pier top," specifically includes the following steps: Install sliding rails at the corresponding positions of the middle truss of the steel truss bridge; The jacks are used to lift the truss synchronously. After each synchronous lifting, the top of the temporary support is compacted with steel plates. Then the jacks are returned to oil and the truss is lifted synchronously again. This process is repeated to lift the entire continuous steel truss to the design position. Wet joints and tensioning of transverse and longitudinal prestressing were carried out within the left and right half spans of the pier top.

4. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (highway and railway) continuous steel truss girders as described in claim 1, characterized in that... The step S4, "removing the temporary support, installing the permanent support on the bridge deck support pad, and grouting into the permanent support," specifically includes the following steps: Once the entire continuous steel truss girder has been lifted to the preset height, the temporary supports are removed. The middle truss support was hoisted onto the bridge and moved to the slideway via the upstream support pad stone for temporary storage. First, install the upstream side support, then slide the middle truss support to the middle truss position via the slide rail for installation, and finally install the downstream side support. Grouting is performed into the formal support.

5. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (highway and railway) continuous steel truss girders as described in claim 4, characterized in that... The step of "grouting into the permanent support" specifically includes the following steps: A steel formwork is laid in the gap between the bottom surface of the lower support plate of the formal support and the top surface of the support pad stone. Grout is injected between the steel formwork and the supporting pad stone to fill the gaps; After grouting is completed, the steel formwork is removed.

6. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (highway and railway) continuous steel truss girders as described in claim 5, characterized in that... The step of "laying steel formwork in the gap between the bottom surface of the lower support plate of the formal support and the top surface of the support pad stone" specifically includes the following steps: Roughen the surface of the support pad stone at the location of the formal support, remove debris from the reserved bolt holes, and lay steel formwork on the top surface of the support pad stone and the bottom surface of the lower support plate.

7. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (highway and railway) continuous steel truss girders as described in claim 5, characterized in that... Before the step of "grouting between the steel formwork and the supporting pad stone", the following steps are also included: Insert sponge strips into the bottom of the steel formwork; A layer of rubber leak-proof strip is fixed on the top surface of the supporting pad stone.

8. The method for post-installation construction of large-tonnage supports for long-span, multi-purpose (road and rail) continuous steel truss girders as described in claim 1, characterized in that, The step S5, "After the grouting of the formal support is completed, the entire continuous steel truss beam is lowered to the top of the formal support and then tightened," specifically includes the following steps: Cover the top surface of the formal support after grouting with burlap sacks or straw mats, and spray water for curing after the grout mortar has set. After maintenance, the entire continuous steel truss girder is lowered to the top of the formal support, and the steel girder and the formal support are then fastened together.

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