Construction method of large-span and large-height difference steel box girder pushing system

Abstract

The present application relates to a kind of construction methods of large-span large-height difference steel box girder pushing system, the combination of steel box girder, existing pier, temporary support, bailey beam and other components is used, and the stability and flexibility of construction are greatly improved.By the temporary support and the opposite side of existing pier setting corbel and bracket, the safety and adaptability of structure are ensured.In addition, the design of assembly adjusting beam makes the assembly height of steel box girder can be adjusted according to specific requirements, greatly facilitates construction operation;Pushing system includes temporary support, forepoling, and is equipped with jack and micro jack and other equipment, these equipment jointly act on the pushing operation of steel box girder.By reasonable connection and support design, the stability in pushing process is effectively guaranteed, so that the possibility of construction under complex conditions is greatly improved.The pushing system can effectively reduce construction cost, shorten construction period, and improve the safety of construction, with significant technical benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bridge engineering and its construction technology, and particularly relates to a construction method of a large-span large-height-difference steel box girder pushing system. BACKGROUND

[0002] Large-span bridges not only effectively solve the traffic bottleneck problem, but also reduce the land occupation area and improve the traffic efficiency. Among various bridge structures, steel box girders gradually become the mainstream choice for large-span bridges due to their excellent mechanical properties and economy. However, the construction technology of steel box girders is relatively complex, especially under large-height-difference and special terrain conditions, the construction difficulty and technical requirements are significantly increased.

[0003] Traditional steel box girder construction methods mainly include hoisting, assembling and erecting processes. These methods can meet the construction requirements to some extent, but in actual application, they still face many challenges. First, the traditional construction method often relies on a large number of temporary support structures and hoisting equipment, which not only increases the construction cost, but also prolongs the construction period. In addition, the stability and safety of the steel box girder during construction are difficult to be effectively guaranteed, especially when constructing under large-height-difference, the problems such as deformation and inclination of the girder body are prone to occur, which further affects the construction quality. In order to overcome the above problems, many researchers and engineers have begun to explore new construction technologies and equipment. Among them, the pushing method as a new construction technology gradually attracts widespread attention. The pushing method sets up a special pushing equipment on the built component, and gradually pushes the steel box girder to the designed position to reduce the dependence on temporary support. This method shows good adaptability and stability in the construction of large-span bridges, especially for construction under large-height-difference and complex terrain.

[0004] However, the existing pushing technology still has some deficiencies. For example, the pushing force and speed need to be accurately controlled during the pushing process to ensure the safety and stability of the girder body. In addition, the setting of the pushing equipment and the connection relationship between the pushing equipment and the main structure also need special attention to avoid unnecessary vibration and deformation during the pushing process. Therefore, how to design an efficient and stable pushing system has become the focus of current technical research.

[0005] In summary, in the face of increasing traffic demand and increasingly complex construction environment, higher requirements are put forward for the construction technology of large-span large-height-difference steel box girders. Therefore, a new type of large-span large-height-difference steel box girder pushing system is urgently needed, which aims to improve the construction efficiency and safety of the steel box girder through reasonable structural design and construction steps. The proposal and implementation of this technology will provide a new solution for the construction of large-span bridges in the future, and promote the further development and innovation of bridge construction technology. SUMMARY

[0006] The application aims to overcome the deficiencies in the prior art and provide a construction method of a large-span and large-height-difference steel box girder incremental launching system.

[0007] The construction method of the large-span and large-height-difference steel box girder incremental launching system comprises the following steps:

[0008] Step one: temporary supports are arranged on both sides of the existing pier, a bottom beam is arranged on the existing pier between the temporary supports, an assembling support is arranged above the bottom beam, and an assembling system is formed;

[0009] Step two: the steel box girder is assembled on the assembling support, and a guide beam system is arranged at the front end of the steel box girder;

[0010] Step three: temporary supports are arranged at intervals on the steel box girder incremental launching route, jacks are arranged on the temporary supports, and cushion beams are arranged on the jacks; fixed frames are arranged on one side of the cushion beams, movable frames are arranged between the two fixed frames, micro jacks and bottom pads are arranged at the bottom of the movable frames, and an incremental launching system is formed; the steel box girder is incrementally launched by using the jacks, and the height of the movable frames is adjusted by using the micro jacks;

[0011] Step four: the temporary supports of the steel box girder are formed by using the movable frames and the fixed frames, and the large-height-difference beam lowering is performed by using the cushion beams and the reverse cushion beams.

[0012] Preferably, the assembling system comprises the steel box girder, the existing pier, the temporary supports and the Bailey beams, the temporary supports are arranged on both sides of the existing pier, the temporary supports comprise pipe piles, pile caps, sleeper beams and main beams, the opposite sides of the temporary supports and the existing pier are provided with support corbels and support brackets, the top of the existing pier is provided with pier top corbels and pier top brackets, the bottom beams are arranged on the support brackets and the pier top brackets, and the bottom beams are located above the water level.

[0013] Preferably, the bottom beams are arranged at intervals and are provided with support rods, the support rods are connected to the bottom beams by support rod anchors, the upper portions of the support rods are provided with top beams and distribution beams, the distribution beams are provided with the Bailey beams, the two sides of the Bailey beams are connected to the two temporary supports by anchor rods and Bailey beam anchors, the Bailey beams are provided with the assembling supports, the bottom portions of the assembling supports are provided with bases, the bases are located on the top surfaces of the Bailey beams, and the top portions of the assembling supports are provided with assembling adjustment beams, which directly bear the steel box girder.

[0014] Preferably, the incremental launching system comprises the temporary supports, the front guide beams and the permanent pier, the temporary supports are arranged at intervals on the incremental launching route, the main beams of the temporary supports are provided with the jacks, the jacks are provided with the cushion beams, one side of the cushion beams is provided with the fixed frames, the movable frames are arranged between the two fixed frames, the bottom portions of the movable frames are provided with the micro jacks and the bottom pads, the movable frames and the two fixed frames are temporarily fixed by connecting rods, and the movable frames are provided with the top pads; during the incremental launching process, the micro jacks at the bottom portions of the movable frames are gradually adjusted to ensure the set height of the top pads.

[0015] As preferred, the guide beam system comprises a front guide beam at the front end of the steel box beam, the front part of the front guide beam has a guide beam boss, the guide beam boss has an embedded groove, the embedded groove has an embedded jack in it, the embedded jack is connected with the guide beam boss by vertical fixing rods, horizontal fixing rods and fixing ends, the embedded jack is connected with a reverse cushion beam by a connecting frame, the reverse cushion beam is opposite to the cushion beam on the temporary support, during jacking, the reverse cushion beam and the cushion beam are movably connected by a first connecting block, a hinge, a connecting shaft and a second connecting block, during pushing, the reverse cushion beam and the cushion beam are disconnected.

[0016] As preferred, the assembly system, the pushing system, the guide beam system and the steel box beam are assembled on the assembly support, the assembly support is adjusted in height according to the assembly requirements of the steel box beam, after the assembly of the steel box beam is completed, the guide beam system is installed at the front end of the steel box beam, and then the steel box beam is pushed forward to the front temporary support and the permanent pier by using the pushing system; when the steel box beam reaches the set position and the beam is lowered, the movable frame and the fixed frame are used as temporary support, the micro jack at the bottom of the movable frame can meet the set height requirement of the top cushion plate, the large-height-difference beam lowering is carried out by using the cushion beam and the reverse cushion beam, the embedded jack and the jack act simultaneously and oppositely, and the demand of large-height-difference beam lowering is met.

[0017] The large-span and large-height-difference steel box beam pushing system is obtained by any of the above-mentioned methods.

[0018] The beneficial effects of the present application are:

[0019] 1) In the assembly system of the present application, a combination of steel box beam, existing pier, temporary support, Bailey beam and other components is adopted, which greatly improves the stability and flexibility of construction. The corbels and brackets are arranged on the opposite sides of the temporary support and the existing pier, which ensures the safety and adaptability of the structure. In addition, the design of the assembly adjustment beam allows the assembly height of the steel box beam to be adjusted according to specific requirements, greatly facilitating the construction operation.

[0020] 2) The pushing system of the present application comprises a temporary support, a front guide beam, and is also equipped with jacks and micro jacks and other equipment, which jointly act on the pushing operation of the steel box beam. Through reasonable connection and support design, the stability during pushing is effectively guaranteed, which greatly improves the possibility of construction under complex conditions. The pushing system can effectively reduce construction cost, shorten construction period and improve construction safety, and has significant technical benefits.

[0021] 3) The guide beam system of the present application can realize efficient connection and support during jacking and pushing through the embedded groove, reverse jack and other means, ensuring the stability of the steel box beam during construction. Especially in the large-height-difference beam lowering, the coordinated action of the embedded jack and the pushing equipment can realize accurate control of the steel box beam, ensuring its safe and smooth landing at the predetermined position. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Figure 1 is a schematic diagram of the construction system in the assembling stage;

[0023] Figure 2 Figure 2 is a schematic diagram of the construction system in the jacking stage;

[0024] Figure 3 Figure 3 is a schematic diagram of the jacking to the temporary support;

[0025] Figure 4 Figure 4 is a schematic diagram of the jacking to the permanent pier;

[0026] Figure 5 Figure 5 is a schematic diagram of the leading beam;

[0027] Figure 6 Figure 6 is a schematic diagram of the cushion beam and the temporary support.

[0028] Figure 1 is a schematic diagram of the construction system in the assembling stage; DETAILED DESCRIPTION

[0029] The present application is further described below in conjunction with the examples. The following examples are intended to help understand the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of modifications can be made to the present application, and these modifications and improvements also fall within the scope of the present application.

[0030] Example 1

[0031] As an example, as shown in Figure 1, the construction method of the large-span and large-height steel box girder jacking system includes the following steps: Figures 1 to 6

[0032] Step 1, construction preparation:

[0033] Step 2, erection of the assembling system:​

[0034] Step 3: Assembly of steel box girder 20:

[0035] Step 4: Construction and Operation of the Top Push System:

[0036] S41, Setting up temporary support 3:

[0037] Temporary supports 3 are set up at intervals along the jacking route. Jacks 24 are installed on the main beams 23 of the temporary supports 3, and pad beams 25 are installed on the jacks 24.

[0038] S42, Installation of fixed bracket 26 and movable bracket 27:

[0039] A fixed frame 26 is installed on one side of the support beam 25, and a movable frame 27 is installed between the fixed frames 26. A miniature jack 31 and a base plate 28 are installed at the bottom of the movable frame 27 to ensure its stability.

[0040] S43, Pushing Operation:

[0041] The steel box girder 20 is pushed using jacks 24. The movable frame 27 is temporarily fixed to the fixed frames 26 on both sides by connecting rods 29 to ensure the stability of the structure during the pushing process. During the pushing process, the miniature jacks 31 at the bottom of the movable frame 27 are gradually adjusted to ensure the set elevation of the top pad 30.

[0042] Step 5: Lowering the beam:

[0043] When the steel box girder 20 reaches the set position, the movable frame 27 and the fixed frame 26 are used as temporary supports. The miniature jacks 31 at the bottom of the movable frame 27 are adjusted to ensure that the set elevation requirements of the top pad 30 are met.

[0044] The large height difference beam drop operation is carried out by using pad beam 25 and reverse pad beam 39. The built-in jack 35 and jack 24 work simultaneously to ensure the smooth drop of the steel box girder 20.

[0045] Step Six: Construction Completion and Inspection

[0046] S61. Construction site cleanup: Organize the construction site and remove waste and debris generated during the construction process.

[0047] S62. Quality Inspection: Conduct a quality inspection on the completed steel box girder 20 and its connecting parts to ensure that it meets the design and relevant standards.

[0048] Example 2

[0049] As another embodiment, this embodiment two proposes a more specific construction method for a large-span, large-elevation-difference steel box girder jacking system based on embodiment one. Steps one to three are as follows:

[0050] Step 1: Construction Preparation

[0051] S11. Material preparation: Procurement of required materials such as steel box girders 20, temporary supports 3, including pipe piles 4, pile caps 21, sleeper beams 22, main beams 23, Bailey beams 14, anchor bolts 16, connectors, etc., and inspection and acceptance of the materials.

[0052] S12. Construction site layout: Set up temporary facilities at the construction site to ensure the safety and smooth flow of traffic in the construction area.

[0053] S13. Installation of permanent supports: Install and construct permanent piers 40 according to design requirements.

[0054] Step Two: Building the Assembly System

[0055] S21. Inspection and cleaning of existing pier 1: Inspect existing pier 1 to ensure that its bearing capacity meets the requirements, and clean the top of the pier and the surrounding environment.

[0056] S22, Temporary support 3 erection:

[0057] Temporary supports 3 are installed on both sides of the existing pier 1 to install pipe piles 4, pile caps 21, sleeper beams 22, and main beams 23. Support brackets 5 and support supports 6 are installed on the opposite sides of the supports to enhance the stability of the support. Pier top brackets 7 and pier top supports 8 are installed on both sides of the existing pier 1.

[0058] Install the bottom support beam 10 between the support bracket 6 and the pier top support bracket 8, ensuring it is level. Install the strut 9 and connect it to the top support beam 12 via strut anchor bolts 11 to ensure the overall stability of the temporary support 3.

[0059] Installation of S23 and Bailey beam 14:

[0060] Install the top support beam and the distribution beam 13 on the upper part of the strut 9 to ensure that they are fixedly connected to the strut 9.

[0061] Bailey beam 14 is installed on distribution beam 13 and connected to the supports on both sides using anchor rods 16 and Bailey beam anchor bolts 15 to ensure the stability of Bailey beam 14.

[0062] S24, Assembling bracket 18:

[0063] Install the assembly bracket 18, with the bottom base 17 placed on top of the Bailey beam 14 to ensure its load-bearing capacity. Install the assembly adjustment beam 19 on top of the assembly bracket 18 to adjust its height to meet the assembly requirements of the steel box girder 20.

[0064] Step 3: Assembly of steel box girder 20:

[0065] Assembly of S31 and steel box girder 20:

[0066] The steel box girder 20 is assembled and fabricated on the assembly support 18, with each component assembled step by step to ensure the firmness of each connection point. During the assembly process, necessary quality checks are carried out to ensure that the assembly quality meets the design requirements.

[0067] S32. Installation of the guide beam system:

[0068] A guide beam system is installed at the front end of the steel box girder 20 to ensure that the guide beams are firmly connected and aligned.

[0069] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0070] Example 3

[0071] As another embodiment, this third embodiment is proposed based on embodiments one and two. This method uses a large-span, large-elevation-difference steel box girder launching system, such as... Figures 1 to 6 As shown, it includes an assembly system, a jacking system, and a guide beam system.

[0072] like Figure 1 As shown, the assembly system includes a steel box girder 20, an existing pier 1, temporary supports 3, and Bailey beams 14. Temporary supports 3 are installed on both sides of the existing pier 1. The temporary supports 3 include pipe piles 4, pile caps 21, sleeper beams 22, and main beams 23. Support brackets 5 and support frames 6 are installed on the opposite side of the temporary supports 3 and the existing pier 1. Pier top brackets 7 and pier top supports 8 are installed on both sides of the existing pier 1. Bottom support beams 10 are installed on the support frames 6 and pier top supports 8, and the bottom support beams 10 are located above the water level line 2. Intermittently arranged supports... The strut 9 is connected to the top support beam 12 via strut anchor bolts 11. The upper part of the strut 9 has a top support beam and a distribution beam 13. The distribution beam 13 has a Bailey beam 14. The two sides of the Bailey beam 14 are connected to the side supports via anchor bolts 16 and Bailey beam anchor bolts 15. The Bailey beam 14 has an assembly bracket 18. The bottom of the assembly bracket 18 has a base 17. The base 17 is located on the top surface of the Bailey beam 14. The top of the assembly bracket 18 has an assembly adjustment beam 19. The assembly adjustment beam 19 directly supports the steel box girder 20.

[0073] like Figures 2 to 4 As shown, the jacking system includes temporary supports 3, a leading beam 32, and permanent piers 40. The temporary supports 3 are distributed at intervals along the jacking route. The main beam 23 of the temporary supports 3 has jacks 24, the jacks 24 have pad beams 25, the pad beams 25 have fixed frames 26 on one side, and the two fixed frames 26 have movable frames 27. The bottom of the movable frame 27 has miniature jacks 31 and bottom pads 28. The movable frame 27 and the fixed connections on both sides can be temporarily fixed by connecting rods 29. The movable frame 27 has a top pad 30.

[0074] like Figure 5 andFigure 6 As shown, the guide beam system includes a front guide beam 32 at the front end of the steel box girder 20. The front part of the front guide beam 32 has a guide beam boss 33. The guide beam boss 33 has an internal groove 34. The internal groove 34 has an inverted internal jack 35. The internal jack 35 and the guide beam boss 33 are connected by a vertical fixing rod 38, a horizontal fixing rod 37, and a fixing end 36. The internal jack 35 is connected to a reverse pad beam 39 by a connecting frame 41. The reverse pad beam 39 is opposite to the pad beam 25 on the temporary support 3. During jacking, the reverse pad beam 39 and the pad beam 25 are movably connected by a first connecting block 42, a hinge 43, a connecting shaft 44, and a second connecting block 45. During pushing, the reverse pad beam 39 and the pad beam 25 are disconnected.

[0075] Based on the aforementioned assembly system, jacking system, and guide beam system, the steel box girder 20 is assembled and fabricated on the assembly support 18. The assembly support 18 can be adjusted in height according to the assembly requirements of the steel box girder 20. After the steel box girder 20 is assembled and fabricated, a guide beam system is installed at its front end. Then, the jacking system is used to push the steel box girder 20 forward to the temporary support 3 and permanent pier 40. When the steel box girder 20 reaches the set position and is lowered, the movable frame 27 and the fixed frame 26 are used as temporary supports. The micro jacks 31 at the bottom of the movable frame 27 can be adjusted to meet the set elevation requirements of the top pad 30. The pad beam 25 and the reverse pad beam 39 are used to lower the girder with a large height difference. The built-in jacks 35 and jacks 24 act simultaneously to meet the needs of lowering the girder with a large height difference.

[0076] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiments 1 and 2 can be referred to each other, and will not be repeated in this application.

[0077] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A construction method for a large-span, large-elevation-difference steel box girder jacking system, characterized in that, Includes the following steps: Step 1: Set up temporary supports on both sides of the existing pier, install bottom support beams on top of the existing pier between the temporary supports, and install assembly supports on top of the bottom support beams to form an assembly system; Step 2: Assemble the steel box girder on the assembly support, and install the guide beam system at the front end of the steel box girder; Step 3: Set up temporary supports at intervals along the jacking route of the steel box girder, install jacks on the temporary supports, and install pad beams on the jacks; install fixed frames on one side of the pad beams, install movable frames between the fixed frames, and install miniature jacks and bottom pads at the bottom of the movable frames to form a jacking system; use the jacks to jack up the steel box girder, and adjust the height of the movable frames using the miniature jacks. Step 4: Use movable and fixed frames as temporary supports for the steel box girder, and use pad beams and reverse pad beams to lower the girder with a large height difference; the guide beam system includes a front guide beam at the front end of the steel box girder, the front part of the front guide beam has a guide beam boss, the guide beam boss has an internal groove, and the internal groove has a reverse internal jack. The internal jack and the guide beam boss are connected by a vertical fixed rod, a horizontal fixed rod and a fixed end. The internal jack is connected to the reverse pad beam by a connecting frame. The reverse pad beam is opposite to the pad beam on the temporary support. During jacking, the reverse pad beam and the pad beam are movably connected by a first connecting block, a hinge, a connecting shaft and a second connecting block. During jacking, the reverse pad beam and the pad beam are disconnected.

2. The construction method of the large-span, large-elevation-difference steel box girder jacking system according to claim 1, characterized in that, The assembly system includes steel box girders, existing piers, temporary supports, and Bailey bridges. Temporary supports are set on both sides of the existing piers. The temporary supports include pipe piles, pile caps, sleeper beams, and main beams. Support brackets and support frames are set on the opposite side of the temporary supports and the existing piers. Pier top brackets and pier top frames are set on both sides of the existing piers. Bottom support beams are set on the support brackets and pier top frames, and the bottom support beams are located above the water level.

3. The construction method of the large-span, large-elevation-difference steel box girder jacking system according to claim 1, characterized in that, The bottom support beam is equipped with spaced struts, which are connected to the bottom support beam by strut anchor bolts. The upper part of the struts has a top support beam and a distribution beam. The distribution beam has a Bailey beam. The two sides of the Bailey beam are connected to temporary supports on both sides by anchor bolts and Bailey beam anchor bolts. The Bailey beam has an assembly support, and the bottom of the assembly support has a base. The base is located on the top surface of the Bailey beam. The top of the assembly support has an assembly adjustment beam, which directly supports the steel box girder.

4. The construction method of the large-span, large-elevation-difference steel box girder jacking system according to claim 1, characterized in that, The jacking system includes temporary supports, a guide beam, and permanent piers. The temporary supports are spaced out along the jacking route. The main beam of the temporary supports has jacks, and the jacks have pad beams. One side of the pad beam has a fixed frame, and there is a movable frame between the two fixed frames. The bottom of the movable frame has micro jacks and a bottom pad plate. The movable frame is temporarily fixed to the fixed frames on both sides by connecting rods. The movable frame has a top pad plate. During the jacking process, the micro jacks at the bottom of the movable frame are gradually adjusted to ensure the set elevation of the top pad plate.

5. The construction method of the large-span, large-elevation-difference steel box girder launching system according to claim 1, characterized in that, The assembly system, jacking system, guide beam system, and steel box girder are assembled and fabricated on the assembly support. The height of the assembly support is adjusted according to the assembly requirements of the steel box girder. After the steel box girder is assembled and fabricated, the guide beam system is installed at its front end. Then, the jacking system is used to push the steel box girder forward to the temporary support and permanent pier in front. When the steel box girder reaches the set position and is lowered, the movable frame and fixed frame are used as temporary supports. The micro jacks at the bottom of the movable frame can be adjusted to meet the set elevation requirements of the top pad. The pad beams and reverse pad beams are used to lower the girder with large height differences. The built-in jacks and the jacks work simultaneously to meet the needs of lowering the girder with large height differences.

6. A large-span, large-elevation-difference steel box girder launching system, characterized in that: Obtained by the method described in any one of claims 1 to 5.

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