用于桥梁钢结构节段整体拼装的平移式空中临时作业平台及其方法

Abstract

This invention discloses a translational aerial temporary work platform and method for the overall assembly of bridge steel structure segments. Erected on the cantilever end of the current construction position on a completed bridge steel structure, the platform includes a platform forward-moving device, a temporary connection system, and an aerial work platform. The temporary connection system includes anchor beams. The platform forward-moving device includes a self-moving beam structure, tracks, and a crawler crane. The self-moving beam structure includes a suspended beam, a lifting device, and a moving trolley. The aerial work platform includes a fixed end and a cantilever end located at the front of the fixed end. The fixed end can be selectively connected to either the suspended beam or the anchor beam. Therefore, this invention transfers ground operations of the main bridge steel structure segments to the air, integrating the advantages of overall segment assembly and effectively reducing the impact on maritime and port operations while ensuring construction quality.

Description

Technical Field

[0001] This invention relates to a translational aerial temporary work platform and its method, belonging to the field of bridge construction technology. Background Technology

[0002] Before steel structure assembly and construction, the selection of construction plan should focus on the following aspects: water conservancy and flood control assessment of construction plan, impact of temporary measures adopted in construction plan on waterway, and safety of temporary construction measures.

[0003] There are two main methods for assembling bridges: one is the segmental hoisting process, and the other is the bracket assembly process.

[0004] Typically, the segmental hoisting process involves assembling the segments at a temporary assembly site, transporting them by waterway to the bridge site, and then installing the main span segments using a bridge deck crane. The biggest advantages of this process are its maturity, minimal investment in temporary facilities, optimal economic benefits, and improved control over the overall welding quality and linearity of the steel structure. It has precedents across China, such as the Ningbo Sanguantang Bridge.

[0005] However, the segmental hoisting process presents the following difficulties: the transportation of segments on the river, the dredging of the waterway, the difficulty in transporting and launching large segmental components, the occupation of major waterways, and the closure of waterways.

[0006] The scaffolding assembly process involves setting up a temporary support system in the river, assembling segments, and then assembling the entire structure. The main challenge of this method lies in the fact that when using this method in channel bends, especially sharp bends, the design of the temporary support structure is extremely difficult to ensure the safety of the temporary measures. This is because, to ensure the misalignment of the channel bottom lines on both sides of the bend, the span of the beams in the temporary support structure must be large, which in turn affects the navigation clearance. Furthermore, there is the safety hazard of transport vessels colliding with the temporary supports during maritime transport accidents. Summary of the Invention

[0007] This invention addresses the shortcomings of existing technologies by providing a movable aerial temporary work platform and its method. The movable aerial temporary work platform comprises two parts: a platform forward-moving device and an aerial work platform. The platform forward-moving device is installed on the upper bridge deck system of the previously constructed steel structure segment, while the aerial work platform is cantilevered and has two installation states. This allows the aerial work platform to serve as a support for the platform forward-moving device during its step-by-step movement, and also as a temporary work site for the main bridge steel structure segment to be constructed. This allows for the assembly of the steel structure segment on the aerial work platform, preparing for the overall welding and assembly of the bridge steel structure segments. Therefore, this invention transfers ground-based work on the main bridge steel structure segments to the air, integrating the advantages of overall segment assembly. While ensuring construction quality, it effectively reduces the impact on maritime and port operations. Furthermore, elevation calculations show that the aerial work platform has no impact on navigation clearance.

[0008] To achieve the above-mentioned technical objectives, the present invention will adopt the following technical solution:

[0009] A movable aerial temporary work platform for the integral assembly of bridge steel structure segments is erected on the cantilever end of the current construction position on the completed bridge steel structure. It includes platform forward movement equipment, a temporary connection system, and the aerial work platform, wherein:

[0010] The temporary connection system includes anchor beams; the anchor beams include at least two sets, one set is installed on the left truss of the bridge corresponding to the current construction position, which is the left anchor beam, and the other set is installed on the right truss of the bridge corresponding to the current construction position, which is the right anchor beam.

[0011] The platform forward-moving equipment includes a self-moving crossbeam structure, tracks, and a crawler crane. The self-moving crossbeam structure includes a suspended crossbeam, a lifting device, and a moving trolley. The suspended crossbeam spans the upper bridge deck system of the current construction position. The moving trolley includes two sets, symmetrically installed on the lower surface of the suspended crossbeam. The crawler crane is placed on the upper bridge deck system of the current construction position. The tracks include two sections, supported by left and right anchor crossbeams respectively, and can be lifted by the crawler crane to the corresponding anchor crossbeam of the next construction position. The lifting device is suspended on the lower surface of the suspended crossbeam and can cause the moving trolley to be installed in the track at the corresponding position or to detach the moving trolley from the track at the corresponding position.

[0012] The aerial work platform includes a fixed platform end and a cantilever end located at the front end of the fixed platform end; the fixed platform end can be fixedly connected to either a suspension beam or an anchoring steel beam.

[0013] Preferably, the aerial work platform includes a platform truss system, a platform bottom connection, and end horizontal connections; the platform truss system includes two trusses, corresponding to the left platform truss system and the right platform truss system; the left platform truss system and the right platform truss system have the same structure and are arranged parallel to each other; the tail ends of the left platform truss system and the right platform truss system are connected into one unit by end horizontal connections, and the lower chords of the left platform truss system and the right platform truss system are connected by platform bottom connections at a position close to the end horizontal connections.

[0014] Preferably, the platform truss system includes a platform truss upper chord, platform truss straight web members, platform truss diagonal web members, and platform truss lower chord; the platform truss upper chord and platform truss lower chord are arranged parallel to each other, and the platform truss upper chord and platform truss lower chord are connected by a number of platform truss straight web members, and two adjacent platform truss straight web members are connected by the platform truss diagonal web members.

[0015] Preferably, the lower chord of the platform truss is provided with several platform crossbeam connecting plates near the tail end. One side of the platform bottom connection is connected to the platform crossbeam connecting plate on the lower chord of the left platform truss system, and the other side is connected to the platform crossbeam connecting plate on the lower chord of the right platform truss system.

[0016] Preferably, the platform bottom connection includes a support beam and a bottom horizontal connection; the number of support beams is three, corresponding to the first to the third support beams, and the second support beam is located between the first and third support beams, and the three support beams are parallel to each other and equidistant; the bottom horizontal connection includes two V-shaped frames that are spliced ​​together, the two ends of the V-shaped frames are respectively connected to the second support beam, and the apex is connected to the first or third support beam;

[0017] There are also three platform beam connecting plates; the two ends of the three supporting beams are respectively connected to the corresponding platform beam connecting plates on the corresponding sides.

[0018] Preferably, the end flat bracing includes a rectangular outer frame and connecting diagonal braces that connect the two diagonals of the rectangular outer frame respectively; the rectangular outer frame is formed by four rods connecting to each other; each connection point is provided with a node plate.

[0019] Preferably, the left anchoring crossbeam comprises two rows, one row of which is installed on the upper chord of the left truss of the bridge and is the first left anchoring crossbeam, and the other row is installed on the lower chord of the left truss of the bridge and is the second left anchoring crossbeam.

[0020] The right-side anchoring beam comprises two rows, one row of which is installed on the upper chord of the right-side truss of the bridge and is the first right-side anchoring beam, and the other row is installed on the lower chord of the right-side truss of the bridge and is the second right-side anchoring beam.

[0021] The two tracks are supported by the first left anchor beam and the first right anchor beam, respectively.

[0022] Preferably, the front ends of the left platform truss system and the right platform truss system are provided with a gap or connected by a guardrail.

[0023] Another technical objective of this invention is to provide a translation method for the aforementioned translational aerial temporary work platform used for the integral assembly of bridge steel structure segments, comprising the following steps:

[0024] Step 1: Homework Preparation

[0025] Preparations for assembling bridge steel structure segments to be joined and for overall assembly with completed bridge steel structures on an aerial work platform include the following steps:

[0026] Step 1.1: Weld and fix the platform truss system on both sides of the aerial work platform to the anchor beams on both sides of the current construction site to realize the suspension of the aerial work platform on the bridge steel structure;

[0027] Step 1.2: Disconnect the aerial work platform from the suspended crossbeam;

[0028] Step 1.3: The lifting cylinder pushes the cylinder out;

[0029] Step 2: Preparation for relocation

[0030] After completing the overall assembly of the bridge steel structure segments to be spliced ​​at the current construction site, preparations are made for moving the aerial work platform to the next construction site, which includes the following steps:

[0031] Step 2.1: Install a set of anchor beams on both sides of the bridge steel structure corresponding to the next construction station; each set of anchor beams includes two layers, which are installed on the upper and lower chords of the truss system on the same side; each layer of anchor beams includes at least two beams, and each anchor beam in each layer is distributed at intervals along the longitudinal direction of the bridge steel structure.

[0032] Step 2.2: Use a crawler crane to lift the track onto the upper anchor beam corresponding to the next construction position for laying;

[0033] Step 2.3: The lifting cylinder retracts to embed the moving trolley under the suspension beam into the track on the corresponding side;

[0034] Step 2.4: Fix the upper chord of the left platform truss system and the right platform truss system close to the tail end to the corresponding positions of the suspension beam, so that the aerial work platform is suspended on the suspension beam;

[0035] Step 2.5: Disconnect the connection between the aerial work platform and the anchor beams on both sides of the current construction site;

[0036] Step 3: Translation

[0037] Start the mobile trolley and move it forward until it moves the aerial work platform to the next construction site;

[0038] Repeat steps one through three until the entire steel structure segment of the bridge is assembled.

[0039] Based on the above-mentioned technical objectives, the present invention has the following advantages compared with the prior art:

[0040] The construction method described in this invention has minimal impact on maritime and port operations. Furthermore, after elevation calculation, the aerial work platform has no impact on navigation clearance. In addition, after the aerial segment hoisting and splicing is completed, the integral segment is welded and assembled to ensure the same construction quality as the integral segment hoisting process. Attached Figure Description

[0041] Figure 1 This is a structural schematic diagram of the translational aerial temporary work platform described in this invention;

[0042] Figure 2 This is the present invention. Figure 1 The diagram shows a suspended aerial work platform mounted on a bridge steel structure.

[0043] Figure 3 yes Figure 1 A schematic diagram of the truss system on the side of the aerial work platform;

[0044] Figure 4 yes Figure 1 A schematic diagram of the bottom horizontal connection structure of the aerial work platform;

[0045] Figure 5 yes Figure 1 A schematic diagram of the end-mounted horizontal connection structure of the aerial work platform;

[0046] Figure 6 This is a schematic diagram showing the use of a crawler crane to lift the current steel structure segment to the overhead work platform;

[0047] Figure 7 This is a schematic diagram of the current steel structure segments being assembled on an aerial work platform and installed onto the main bridge steel structure;

[0048] Figure 8 This is a structural schematic diagram of the main bridge's steel structure segments;

[0049] In the diagram: 1-1, Upper bridge deck system; 1-2, Lower bridge deck system; 1-3, Upper chord of the left truss of the bridge; 1-4, Lower chord of the left truss of the bridge; 1-5, Upper chord of the right truss of the bridge; 1-6, Lower chord of the right truss of the bridge; 2-1, Lower anchoring beam; 2-2, Upper anchoring beam; 3-1, Right truss system of the platform; 3-1-1, Upper chord of the platform truss; 3-1-2, Straight web members of the platform truss; 3-1-3, Diagonal web members of the platform truss; 3-1-4, Lower chord of the platform truss; 3-1-5, Connecting plate of the platform beam. 3-2. Left truss system of the platform; 3-3. Bottom connection of the platform; 3-4. Guardrail; 3-5. End horizontal connection; 3-6. Bottom horizontal connection; 3-7. Support beam; 4-1. Suspension beam; 4-2. Rail transport system; 5. Previous main bridge truss segment; 6-1. Lower chord anchor point; 6-2. Upper chord anchor point; 7. Main bridge truss segment to be constructed; 8. Tracked crane track. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0051] like Figures 1 to 8As shown, the present invention describes a movable aerial temporary work platform for the overall assembly of bridge steel structure segments, which is erected on the cantilever end of the current construction position on the completed bridge steel structure. The movable aerial temporary work platform comprises two parts: a platform forwarding device and an aerial work platform. The platform forwarding device is installed on the upper bridge deck system 1-1 of the previously erected steel structure segment 5, while the aerial work platform is cantilevered and has two installation states. This allows the aerial work platform to serve as a support for the platform forwarding device's step-by-step movement, and also as a temporary work site for the steel structure segment 7 to be constructed. This allows the steel structure segment assembly to be completed on the aerial work platform, preparing for the overall welding and assembly of the bridge steel structure segments. Therefore, the present invention transfers the ground work of the main bridge steel structure segments to the air, integrating the advantages of overall segment assembly. While ensuring construction quality, it effectively reduces the impact on maritime and port operations. Furthermore, elevation calculations show that the aerial work platform has no impact on navigation clearance.

[0052] In this invention, the translational aerial temporary work platform includes platform forwarding equipment, a temporary connection system, and an aerial work platform, wherein:

[0053] The temporary connection system includes anchor beams; the anchor beams include at least two sets, one set is installed on the left truss system of the current construction position as the left anchor beam, and the other set is installed on the right truss system of the current construction position as the right anchor beam.

[0054] The platform forward-moving equipment includes a self-moving crossbeam structure, tracks, and a crawler crane. The self-moving crossbeam structure includes a suspended crossbeam 4-1, a lifting device, and a moving trolley 4-2. The suspended crossbeam 4-1 spans the upper bridge deck system 1-1 of the current construction position. The moving trolley 4-2 includes two sets, symmetrically installed on the lower surface of the suspended crossbeam 4-1. The crawler crane is placed on the upper bridge deck system 1-1 of the current construction position. The tracks include two sections, supported by left and right anchor crossbeams respectively, and can be lifted by the crawler crane to the corresponding anchor crossbeam of the next construction position. The lifting device is suspended on the lower surface of the suspended crossbeam 4-1 and can cause the moving trolley 4-2 to be installed in the track at the corresponding position or to detach the moving trolley 4-2 from the track at the corresponding position.

[0055] The aerial work platform includes a fixed platform end and a cantilever end located at the front end of the fixed platform end; the fixed platform end can be fixedly connected to either the suspension beam 4-1 or the anchoring steel beam.

[0056] Preferably, the aerial work platform includes a platform truss system, a platform bottom connector 3-3, and an end horizontal connector 3-5; the platform truss system includes two trusses, corresponding to the left platform truss system 3-2 and the right platform truss system 3-1; the left platform truss system 3-2 and the right platform truss system 3-1 have the same structure and are arranged parallel to each other; the tail ends of the left platform truss system 3-2 and the right platform truss system 3-1 are connected as one unit by the end horizontal connector 3-5, and the lower chords of the left platform truss system 3-2 and the right platform truss system 3-1 are connected by the platform bottom connector 3-3 at a position close to the end horizontal connector 3-5.

[0057] Preferably, the platform truss system includes a platform truss upper chord 3-1-1, a platform truss straight web member 3-1-2, a platform truss diagonal web member 3-1-3, and a platform truss lower chord 3-1-4; the platform truss upper chord 3-1-1 and the platform truss lower chord 3-1-4 are arranged parallel to each other, and the platform truss upper chord 3-1-1 and the platform truss lower chord 3-1-4 are connected by a number of platform truss straight web members 3-1-2, and two adjacent platform truss straight web members 3-1-2 are connected by the platform truss diagonal web members 3-1-3.

[0058] Preferably, the lower chord of the platform truss 3-1-4 is provided with several platform crossbeam connecting plates 3-1-5 near the tail end. One side of the platform bottom connector 3-3 is connected to the platform crossbeam connecting plate 3-1-5 on the lower chord of the left platform truss system 3-2, and the other side is connected to the platform crossbeam connecting plate 3-1-5 on the lower chord of the right platform truss system 3-1.

[0059] Preferably, the platform bottom connection 3-3 includes a support beam 3-7 and a bottom horizontal connection 3-6; the number of support beams 3-7 is three, corresponding to the first to the third support beams 3-7, and the second support beam 3-7 is located between the first and third support beams 3-7, and the three support beams 3-7 are parallel to each other and equidistant; the bottom horizontal connection 3-6 includes two V-shaped frames that are spliced ​​together, the two ends of the V-shaped frames are respectively connected to the second support beam 3-7, and the apex is connected to the first support beam 3-7 or the third support beam 3-7;

[0060] There are also three platform crossbeam connecting plates 3-1-5; the two ends of the three supporting crossbeams 3-7 are respectively connected to the corresponding platform crossbeam connecting plates 3-1-5 on the corresponding side.

[0061] Preferably, the end flat bracing 3-5 includes a rectangular outer frame and connecting diagonal braces that connect the two diagonals of the rectangular outer frame respectively; the rectangular outer frame is formed by four rods surrounding each other; each connection point is provided with a node plate.

[0062] Preferably, the left anchoring beam comprises two rows, one row being installed on the upper chord 1-3 of the left truss of the bridge, serving as the first left anchoring beam 2-1, and the other row being installed on the lower chord 1-4 of the left truss of the bridge, serving as the second left anchoring beam 2-2; the right anchoring beam comprises two rows, one row being installed on the upper chord 1-5 of the right truss of the bridge, serving as the first right anchoring beam, and the other row being installed on the lower chord 1-6 of the right truss of the bridge, serving as the second right anchoring beam; in this case, the two tracks are respectively supported by the first left anchoring beam 2-1 and the first right anchoring beam. Specifically, an upper chord anchor point 6-2 is provided at the corresponding position of the upper chord 1-3 of the left truss of the bridge for installing the second left anchor beam 2-2. A lower chord anchor point 6-1 is provided at the corresponding position of the lower chord 1-4 of the left truss of the bridge for installing the first left anchor beam 2-1. Similarly, corresponding anchor points are also provided at the corresponding positions of the right truss of the bridge for installing the corresponding anchor beams.

[0063] Preferably, the front ends of the left platform truss system 3-2 and the right platform truss system 3-1 are provided with a gap or connected by a guardrail 3-4.

[0064] Based on the aforementioned translational aerial temporary work platform for the integral assembly of bridge steel structure segments, this invention provides a translation method for the translational aerial temporary work platform, comprising the following steps:

[0065] Step 1: Homework Preparation

[0066] Preparations for assembling bridge steel structure segments to be joined and for overall assembly with completed bridge steel structures on an aerial work platform include the following steps:

[0067] Step 1.1: Weld and fix the platform truss system on both sides of the aerial work platform to the anchor beams on both sides of the current construction site to realize the suspension of the aerial work platform on the bridge steel structure;

[0068] Step 1.2: Disconnect the connection between the aerial work platform and the suspended crossbeam 4-1;

[0069] Step 1.3: The lifting cylinder pushes the cylinder out;

[0070] Step 2: Preparation for relocation

[0071] After completing the overall assembly of the bridge steel structure segments to be spliced ​​at the current construction site, preparations are made for moving the aerial work platform to the next construction site, which includes the following steps:

[0072] Step 2.1: Install a set of anchor beams on both sides of the bridge steel structure corresponding to the next construction station; each set of anchor beams includes two layers, which are installed on the upper and lower chords of the truss system on the same side; each layer of anchor beams includes at least two beams, and each anchor beam in each layer is distributed at intervals along the longitudinal direction of the bridge steel structure.

[0073] Step 2.2: Use a crawler crane to lift the track onto the upper anchor beam corresponding to the next construction position for laying;

[0074] Step 2.3: The lifting cylinder retracts to embed the moving trolley 4-2 under the suspension beam 4-1 into the track on the corresponding side;

[0075] Step 2.4: Fix the upper chord of the left platform truss system 3-2 and the right platform truss system 3-1 close to the tail end to the corresponding positions of the suspension beam 4-1, so that the aerial work platform is suspended on the suspension beam 4-1.

[0076] Step 2.5: Disconnect the connection between the aerial work platform and the anchor beams on both sides of the current construction site;

[0077] Step 3: Translation

[0078] Start the mobile trolley 4-2, causing it to move forward until it moves the aerial work platform to the next construction position;

[0079] Repeat steps one through three until the entire steel structure segment of the bridge is assembled.

[0080] Example 1

[0081] This embodiment mainly illustrates the structural design of the aerial work platform, as detailed below:

[0082] (1) Structural design principles

[0083] 1) Meets the bearing capacity requirements under vertical loads.

[0084] The main span of the main bridge steel structure has a beam height of 6 meters. To meet the requirements for aerial assembly of steel structure segments, the height of the aerial work platform will be close to 8 meters. A truss structure system was chosen to enhance the overall load-bearing capacity of the structure. The structural design also references the formwork structure for cantilevered concrete continuous beam construction. However, due to the need for hoisting segmental components, a horizontal connection cannot be installed directly above the cantilever end of the aerial work platform. Therefore, the overall stability of the platform during construction must be considered in the overall truss structure design.

[0085] 2) Meets the bearing capacity requirements under lateral loads.

[0086] Wind protection measures are required for the welding of steel structures of cantilever aerial work platforms. As a result, the cantilever end of the platform will bear a large lateral wind load, which has a significant impact on the overall stability and structural stress of the work platform. The influence of lateral wind load must be fully considered when designing and calculating the work platform.

[0087] 3) Adapting to the influence of bridge cross slope

[0088] The cross section of the super-large bridge has a 2% cross slope, which causes the left and right truss spaces to have different elevations, thus affecting the anchorage structure of the aerial work platform. Therefore, the design of the aerial work platform must consider the rationality of the platform anchorage measures under the influence of the cross slope.

[0089] (2) Structural component design

[0090] The main load-bearing structure of the aerial work platform adopts a truss structure. The main truss chord is HW400×400×13×21, with 10mm steel plates attached to both sides of the upper chord to form a rectangular section. The main truss straight web members are HW300×300×10×15, and the diagonal web members adopt a cross tie rod design. The diagonal web members in front of the lower front support point are made of double-jointed 25a channel steel (limbs facing each other), and the remaining positions are made of double-jointed 20a channel steel (limbs facing each other).

[0091] Double-segment HW400 I-beams are installed below the first three vertical members of the truss to support the crossbeams 3-7, which also serve as the supporting crossbeams 3-7 for the operating platform distribution beams. Diamond-shaped horizontal bracing is installed between the supporting crossbeams 3-7. To increase the overall stability between the left and right trusses, transverse connections (double-segment 20a channel steel) are installed at the ends of the trusses. See the structural design drawings of the aerial work platform for details. Figure 3-5 As shown.

[0092] (3) Structural anchorage design

[0093] The main bridge uses a fully welded steel structure system, so no additional temporary bolt system is required for construction. Therefore, the aerial work platform is connected to the main bridge truss system via welds.

[0094] The boundary constraints of the aerial work platform are provided by "HM700 steel":

[0095] 1) The connecting steel section (i.e. the anchoring crossbeam mentioned above) is located on the top plate of the main truss system chord of the main bridge. The upper chord is leveled by wedge-shaped pads, and the lower chord is leveled by 30mm steel plates.

[0096] 2) The aerial work platform is connected to the connecting steel sections by the outward cantilever stiffening of the web members, which not only balances the impact of the longitudinal slope on the installation accuracy, but also can adapt to the 2% cross slope requirement of the main truss structure.

[0097] 3) The reaction force of the upper chord is relatively small (less than 300kN), so the wedge-shaped pad is connected by double-sided fillet welds, and no additional welds are set between the steel section and the upper chord;

[0098] 4) The lower chord reaction force is relatively large. The steel section is welded to the lower chord web members to bear the vertical reaction force. A 30mm pad is set between the steel section and the top plate of the lower chord for leveling. Double-sided fillet welds are used for connection to resist the horizontal reaction force.

[0099] 5) Each segment of the upper and lower chords is equipped with a connecting steel section. The upper chord steel section can be welded on site or made in the factory, but the lower chord steel section must be welded in the factory, otherwise the overhead welding connection is more difficult.

[0100] Furthermore, after cleaning the welds on the top chord plate, asphalt paving is poured, which has relatively low requirements for appearance quality. Fillet welds are used to connect the web members of the bottom chord to the connecting steel sections, and to connect the bottom chord plate to the leveling pads. Among these, the fillet welds on the inner web plate and the top plate are cleaned by downward welding, which is relatively easy, while the fillet welds on the outer web plate require upward welding, which is more difficult. The platform anchorage design is as follows... Figure 2 As shown.

[0101] (4) Structural component verification

[0102] Based on the cross-sectional design, structural calculations were performed using Midas software. The external load was considered to be 1600 kN, along with the lateral wind load on the vertical platform, and anchorage loads were applied as needed. Among the members, the double-channel steel structure uses a back-to-back configuration, with an outer edge distance of 270 mm, which is the net distance between the top and bottom plates of the HW300×300×10×15 I-beams.

[0103] Midas' internal force calculations indicate that the maximum stress in each member of the aerial work platform is 139 MPa, which meets the allowable stress control value of 140 MPa. Simultaneously, the overall stability of the aerial work platform was verified using Midas' calculation software. The results show that the stability coefficient of the aerial work platform is 4.3, meeting the structural stability requirements.

[0104] Example 2

[0105] This embodiment mainly illustrates the forward movement of the aerial work platform during bridge construction, as detailed below:

[0106] After the completion of one segment of construction, the aerial work platform is moved to the next segment for further construction. The platform's forward movement equipment is a crucial component of the overall platform structure. Since the platform's overall weight exceeds 60 tons, the crawler cranes used on the bridge deck cannot complete the forward movement. Therefore, the project team designed a track-mounted forward movement device (i.e., the platform itself) to accomplish the overall forward movement of the platform.

[0107] like Figure 1 As shown, the track-mounted transfer device is set at the anchor beam position. Before the track is laid, 1-2 additional beams are added. At the same time, wedge-shaped steel plates are used to level the track slope. The lifting jack is set below the suspension beam 4-1. After the work platform is lifted as a whole, the track and the traverse trolley are installed. The front moving power device is used to move forward and then to the designated position.

[0108] Example 3

[0109] This embodiment mainly illustrates the main span segment assembly process based on the above-mentioned aerial work platform, and the specific details are as follows:

[0110] 3.1. Segment division of the main span steel structure

[0111] (1) Segment division determination

[0112] Based on the construction progress of the main bridge's steel structure aerial work platform, the project team divided the main bridge's steel structure into segments. The structure of each segment is as follows: Figure 8 As shown, the main bridge segment includes the upper chord 9-1 and the lower chord. A rectangular space 9-3 can be formed between the tail end of the main bridge steel structure segment and the completed main bridge structure. This effectively controls the accumulation of assembly errors during segment assembly and ensures the overall alignment of the steel structure. The upper chord support point rests on the completed main bridge structure, which not only distributes the load of the aerial work platform but also facilitates the adjustment of the overall segment position.

[0113] (2) Determination of cross-sectional shape

[0114] When the upper and lower bridge decks, as well as the upper and lower chords, all have a 2% cross slope, considering the anchoring requirements for the aerial work platform installation, in addition to maintaining the original 2% cross slope of the upper and lower bridge decks, the bottom plate of the upper chord and the top plates of the lower chord are adjusted to be horizontal. Simultaneously, to meet the requirements of the aerial work platform, the upper bridge deck is a cantilever plate installed later in section 1-1. After the adjustments are completed, during the construction of the aerial work platform on the main span of the bridge, the lower anchoring beam is located on the top surface of the lower chord (horizontally positioned), and the bottom surface of the lower chord is adjusted to be horizontal to ensure temporary stability during the early stages of truss installation.

[0115] 3.2. Segmental Assembly of Tracked Cranes

[0116] After the aerial work platform is installed, the crawler crane is positioned. The spacing between the bridge deck anchor beams is set at 7 meters. The maximum dimensions of the 100-ton crawler crane are 7780×6350 (length×width) mm. The 7-meter-wide travel space of the crawler crane is sufficient for its movement. At the same time, the anchor beams can also serve as a limiting device for the crawler crane (the end anchor beams are extended), ensuring the safety of the crawler crane during operation. The segmental components are transported to the rear of the crawler crane via bridge deck transport equipment (limiting rails + transport flatbed trucks), where the crawler crane completes the segmental lifting.

[0117] 3.3. Adjustment of walking jack

[0118] After the overall segment is assembled on the aerial work platform, Liye walking jacks complete the final position adjustment. The walking jacks can use the two steps of "lifting" and "pushing" to adjust the elevation and plane position of the overall segment to ensure the accuracy of the overall alignment of the main bridge.

Claims

1. A method for translating a temporary aerial work platform used for the integral assembly of bridge steel structure segments, characterized in that, A movable aerial temporary work platform for the overall assembly of bridge steel structure segments is erected on the cantilever end of the current construction position on the completed bridge steel structure. It includes platform relocation equipment, a temporary connection system, and the aerial work platform itself. The temporary connection system includes anchor beams; the anchor beams include at least two sets, one set is installed on the left truss of the bridge corresponding to the current construction position, which is the left anchor beam, and the other set is installed on the right truss of the bridge corresponding to the current construction position, which is the right anchor beam. The platform forward moving equipment includes a self-moving crossbeam structure, tracks, and a crawler crane. The self-moving crossbeam structure includes a suspended crossbeam, a lifting cylinder, and a moving trolley. The suspended crossbeam spans the upper bridge deck system of the current construction position. The moving trolley includes two sets, symmetrically installed on the lower surface of the suspended crossbeam. The crawler crane is placed on the upper bridge deck system of the current construction position. The tracks include two sections, supported by left and right anchor crossbeams respectively, and can be lifted by the crawler crane to the corresponding anchor crossbeam of the next construction position. The lifting cylinder is suspended on the lower surface of the suspended crossbeam and can cause the moving trolley to be installed in the track at the corresponding position or to detach the moving trolley from the track at the corresponding position. The aerial work platform includes a fixed platform end and a cantilever platform end located at the front end of the fixed platform end; the fixed platform end can be fixedly connected to either a suspension beam or an anchor beam. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments includes the following steps: Step 1: Homework Preparation Preparations for assembling bridge steel structure segments to be joined and for overall assembly with completed bridge steel structures on an aerial work platform include the following steps: Step 1.1: Weld and fix the platform truss system on both sides of the aerial work platform to the anchor beams on both sides of the current construction site to realize the suspension of the aerial work platform on the bridge steel structure; Step 1.2: Disconnect the aerial work platform from the suspended crossbeam; Step 1.3: The lifting cylinder pushes the cylinder out; Step 2: Preparation for relocation After completing the overall assembly of the bridge steel structure segments to be spliced ​​at the current construction site, preparations are made for moving the aerial work platform to the next construction site, which includes the following steps: Step 2.1: Install a set of anchor beams on both sides of the bridge steel structure corresponding to the next construction station; each set of anchor beams includes two layers, which are installed on the upper and lower chords of the truss system on the same side; each layer of anchor beams includes at least two beams, and each anchor beam in each layer is distributed at intervals along the longitudinal direction of the bridge steel structure. Step 2.2: Use a crawler crane to lift the track onto the upper anchor beam corresponding to the next construction position for laying; Step 2.3: The lifting cylinder retracts to embed the moving trolley under the suspension beam into the track on the corresponding side; Step 2.4: Fix the upper chord of the left platform truss system and the right platform truss system close to the tail end to the corresponding positions of the suspension beam, so that the aerial work platform is suspended on the suspension beam; Step 2.5: Disconnect the connection between the aerial work platform and the anchor beams on both sides of the current construction site; Step 3: Translation Start the mobile trolley and move it forward until it moves the aerial work platform to the next construction site; Repeat steps one through three until the entire steel structure segment of the bridge is assembled.

2. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 1, characterized in that, The aforementioned aerial work platform includes a platform truss system, a platform bottom connection, and end horizontal connections. The platform truss system comprises two members, corresponding to the left platform truss system and the right platform truss system. The left platform truss system and the right platform truss system have the same structure and are arranged parallel to each other. The tail ends of the left platform truss system and the right platform truss system are connected as one unit by end horizontal connections, and the lower chords of the left platform truss system and the right platform truss system are connected by platform bottom connections at a position close to the end horizontal connections.

3. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 2, characterized in that, The platform truss system includes a platform truss top chord, platform truss straight web members, platform truss diagonal web members, and platform truss bottom chord. The platform truss top chord and platform truss bottom chord are arranged parallel to each other, and the platform truss top chord and platform truss bottom chord are connected by several platform truss straight web members, and two adjacent platform truss straight web members are connected by the platform truss diagonal web members.

4. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 3, characterized in that, Several platform beam connecting plates are installed near the tail end of the lower chord of the platform truss. One side of the platform bottom connection is connected to the platform beam connecting plate on the lower chord of the left platform truss system, and the other side is connected to the platform beam connecting plate on the lower chord of the right platform truss system.

5. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 4, characterized in that, The platform bottom connection includes a support beam and a bottom horizontal connection; there are three support beams, corresponding to the first to the third support beams, and the second support beam is located between the first and third support beams. The three support beams are parallel to each other and equidistant; the bottom horizontal connection includes two V-shaped frames that are spliced ​​together. The two ends of the V-shaped frames are connected to the second support beam, and the apex is connected to the first or third support beam. There are also three platform beam connecting plates; the two ends of the three supporting beams are respectively connected to the corresponding platform beam connecting plates on the corresponding sides.

6. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 5, characterized in that, The end flat bracing includes a rectangular outer frame and connecting diagonal braces that connect the two diagonals of the rectangular outer frame respectively; the rectangular outer frame is formed by four rods connecting to each other; each connection point is provided with a node plate.

7. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 6, characterized in that, The left-side anchoring beam comprises two rows, one row of which is installed on the upper chord of the left-side truss of the bridge and is the first left-side anchoring beam, and the other row is installed on the lower chord of the left-side truss of the bridge and is the second left-side anchoring beam. The right-side anchoring beam comprises two rows, one row of which is installed on the upper chord of the right-side truss of the bridge and is the first right-side anchoring beam, and the other row is installed on the lower chord of the right-side truss of the bridge and is the second right-side anchoring beam. The two tracks are supported by the first left anchor beam and the first right anchor beam, respectively.

8. The translation method for the translational aerial temporary work platform used for the integral assembly of bridge steel structure segments according to claim 7, characterized in that, The left and right platform truss systems are connected at their front ends by a gap or by a guardrail.

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