Segmental prefabricated single-box single-cell variable-height prestressed concrete box girder and construction method thereof

Abstract

The application relates to a segment prefabricated single-box single-chamber variable-height prestressed concrete box girder and a construction method thereof, and the scheme comprises the following steps: step 1, installing embedded parts; step 2, installing the formwork of a zero block; step 3, pouring the zero block; step 4, installing the support of a first block; step 5, installing a bridge erecting machine; step 6, positioning the first block; step 7, pouring a wet joint; and step 8, installing the remaining prefabricated segments: the installation of the remaining prefabricated segments except the zero block and the first block adopts a mode of simultaneous suspension and segmented connection to complete the construction. The application innovates the construction mode of the zero block formwork system and avoids support erection; the first block is placed and installed by using a support platform, the installation precision and efficiency of the first block are improved; the remaining prefabricated segments adopt the mode of simultaneous suspension and segmented simultaneous connection, and the assembly efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of building engineering technology, specifically to segmental precast single-box single-cell variable-height prestressed concrete box girders and their construction methods. Background Technology

[0002] Currently, the zero block of precast box girder segment is generally constructed using the scaffolding method. Erecting the scaffolding requires installing and dismantling the scaffolding, which is time-consuming and material-intensive, and places high demands on the foundation conditions. Apart from the zero block, the remaining precast segments are typically constructed using a bridge erecting machine. The connection between the first and zero blocks determines the overall bridge alignment and is the most crucial aspect of the entire precast bridge assembly. The bridge erecting machine suspends the first block in place, adjusts its position according to the bridge alignment, and then pours the wet joint between the zero and first blocks. Because the first block is suspended, adjusting its position is difficult and cumbersome, resulting in slow construction speed and inaccurate adjustments that hinder bridge alignment control.

[0003] Therefore, there is an urgent need for a segmental precast single-box single-cell variable-height prestressed concrete box girder and its construction method to solve the problems existing in the current technology.

[0004] Application content

[0005] The purpose of this application is to address the aforementioned problems existing in the prior art by providing segmental precast single-box single-cell variable-height prestressed concrete box girders and their construction methods.

[0006] To achieve the aforementioned objectives, this application adopts the following technical solution: The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder includes the following steps:

[0007] Step 1: Install embedded parts: When the bridge pier is being poured, the upper first anchor plate and the lower second anchor plate are symmetrically installed near the top of the pier, and the first sleeve and the second sleeve are installed at intervals on the first anchor plate and the second anchor plate, respectively.

[0008] Step 2: Install the template for block 0: Use the embedded parts on the top of the pier to install the template and its support system for block 0;

[0009] Step 3: Pour the zero block concrete: Pour the zero block concrete, and remove the formwork and its support system after curing.

[0010] Step 4: Install the support for Block 1: Connect the pier top platform using the embedded parts on the pier top, which serves as the support platform for Block 1.

[0011] Step 5: Install the bridge erecting machine: Install support legs on top of the multiple completed zero blocks, and use the support legs to install the bridge erecting machine;

[0012] Step 6, Positioning of Block 1: Use the bridge erecting machine to hoist Block 1 into position, place Block 1 on the adjusting plate, use the adjusting plate to accurately position Block 1, and use the connecting steel to temporarily connect Block 1 to Block 0.

[0013] Step 7: Pour wet joint: After the No. 1 block is accurately positioned, pour the wet joint between the No. 0 block and the No. 1 block, and then remove the support system of the No. 1 block;

[0014] Step 8: Install the remaining precast segments: Except for block 0 and block 1, the remaining precast segments are installed by simultaneous suspension and segmented connection to complete the construction.

[0015] Furthermore, in step 2, the installation method of the zero-block template and its support system is as follows:

[0016] The second sleeve is used to connect the cross brace, the second connecting block is installed using the connecting cross brace, and the upper template system is placed and connected using the second connecting block.

[0017] The connecting hole of the second connecting block is fitted with a connecting component, and the installation column is fitted inside the second connecting block. The column extends upward to the same elevation as the back rib.

[0018] The second connecting block is equipped with a support template at the top. The support template is fixed by the spaced back ribs, and the two support templates on both sides are pulled against the back ribs by tie rods. During installation, the back ribs are fitted onto the top of the column through the connecting holes of the back ribs to fix the back ribs to the column.

[0019] The outer side of the back brace is connected to the extension of the cross brace using a stabilizing rod.

[0020] Furthermore, the second connecting block is a square prefabricated block arranged at intervals, and the second connecting block has multiple horizontal and vertical connecting holes.

[0021] Furthermore, in step 2, the installation method of the zero-block template and its support system is as follows:

[0022] During the construction of the pier, a protective concrete of a certain thickness is poured on the outside of the pier.

[0023] The portal-shaped suspended formwork is installed on the top of the pier column. The upper part of the suspended formwork is used to define the area of ​​the zero block to be poured, and the lower part of the suspended formwork straddles the outside of the protective concrete.

[0024] The lower panel of the suspended formwork is fixed to the first anchor plate and the second anchor plate using temporary fixing rods;

[0025] Protective concrete is used to ensure that the outer boundary of the pier is aligned with the boundary of block zero.

[0026] Furthermore, in step 4: the installation method of the pier-top platform is as follows:

[0027] The first connecting block and the second connecting block are connected by the first sleeve and the second sleeve respectively, and the second sleeve is also connected to the horizontal connecting cross brace.

[0028] Vertical supports are provided between longitudinally adjacent connecting cross braces, and support plates and adjustment plates are installed on several connecting cross braces at the top;

[0029] The bottom connecting cross brace is connected to the first connecting block by multiple diagonal braces.

[0030] Furthermore, in step 5, the lower support, vertical bar, reinforcing bar and upper support are connected to both sides of the outrigger, and the top of the outrigger and the upper support simultaneously support the bridge erecting machine, improving the stability of the bridge erecting machine.

[0031] Furthermore, in step 6, the height of the adjustment plate can be linearly adjusted. The bottom slope of block one is adjusted by adjusting the adjustment plate, thereby adjusting the positioning posture of the height-adjusting segment.

[0032] Furthermore, in step 8, multiple precast segments are simultaneously positioned and sequentially assembled and connected to the preceding segments, and temporary prestress is simultaneously applied to the multiple precast segments.

[0033] Furthermore, Block 0, the wet joint, and Block 1 together constitute the pier top anchoring unit, which uses the pier top support as a working platform.

[0034] The segmental precast single-box single-cell variable-height prestressed concrete box girder is constructed using the aforementioned segmental precast single-box single-cell variable-height prestressed concrete box girder construction method.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] 1. This application avoids the cumbersome construction of the zero block by using pre-reserved components on the pier column to install the zero block template; it innovates the support system for the zero block template on the pier top, using multiple connecting blocks, columns, and stabilizing rods to improve the stability of the template; it innovates the suspended template for the zero block on the pier top, which is integrally formed and uses a stabilizing method that straddles the pier top, reducing the use of diagonal braces and back braces.

[0037] 2. This application utilizes a pier-top support system to support the No. 1 block, avoiding the need for suspension during its placement and improving the adjustment efficiency and placement accuracy of the No. 1 block. Since the No. 1 block is the starting point for precast segments, improving its placement accuracy benefits the overall bridge alignment accuracy. Furthermore, adjusting plates are used to adjust the bottom slope of the No. 1 block, thereby adjusting the placement posture of the height-adjustable segments.

[0038] 3. Except for Block 0 and Block 1, which are constructed using a support system, the remaining precast segments are simultaneously suspended and connected in segments. This method positions multiple precast segments simultaneously and assembles them with the preceding segment at the same time, which improves assembly efficiency compared to assembling and connecting individual segments one by one. Attached Figure Description

[0039] Figure 1 This is a transverse cross-sectional view of the precast segmental beam bridge construction in this application;

[0040] Figure 2 for Figure 1 Cross-sectional view of the top support system of the central pier column;

[0041] Figure 3 Method 1 for constructing the formwork system for the zero block on the pier top;

[0042] Figure 4 Method 2 for the construction of the formwork system for the zero block on the pier top;

[0043] Figure 5 This is a construction flowchart for this application.

[0044] In the diagram, 1. Pier column; 2. First anchor plate; 3. First sleeve; 4. First connecting block; 5. Second anchor plate; 6. Second sleeve; 7. Second connecting block; 8. Diagonal brace; 9. Connecting horizontal brace; 10. Vertical brace; 11. Support plate; 12. Adjusting plate; 13. Pier top anchoring unit; 14. Block No. 0; 15. Block No. 1; 16. Wet joint; 17. Connecting steel beam; 18. Lower horizontal brace; 19. Reinforcing rod; 20. Vertical rod; 21. Upper horizontal brace; 22. Outrigger; 23. Bridge erecting machine; 24. Hanging rod; 25. Precast segment; 26. Column; 27. Stabilizing rod; 28. Support formwork; 29. ​​Back rib; 30. Tie rod; 31. Suspended formwork; 32. Protective concrete; 33. Temporary fixing rod. Detailed Implementation

[0045] 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, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0046] Those skilled in the art should understand that, in the disclosure of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, the above terms should not be construed as limitations on this application.

[0047] like Figure 1-5 As shown, the construction method for this segment of precast single-box single-cell variable-height prestressed concrete box girder includes the following steps:

[0048] Step 1: Install embedded parts:

[0049] During the pouring of the bridge pier 1, near the top of the pier, the upper first anchor plate 2 and the lower second anchor plate 5 are symmetrically installed. The first sleeve 3 and the second sleeve 6 are installed at intervals on the first anchor plate 2 and the second anchor plate 5, respectively. The sleeves are used to connect the subsequent support units.

[0050] Step 2: Install template 14 (block 0):

[0051] There are two methods for installing template 14 (block 0):

[0052] Method 1: Use the second sleeve 6 to connect the connecting cross brace 9, use the connecting cross brace 9 to install the second connecting block 7, use the second connecting block 7 to support and connect the upper template system, the second connecting block 7 is a square precast block with intervals, the second connecting block 7 has multiple horizontal and vertical connecting holes, the connecting components are fitted through the connecting holes, the column 26 is fitted and installed in the second connecting block 7, the column 26 extends upward to the same elevation as the back rib 29.

[0053] The second connecting block 7 has a support template 28 installed on top. The support template 28 is fixed by the spaced back ribs 29. The two support templates 28 and the back ribs 29 are pulled together by the tie rods 30. The back ribs 29 have connecting holes. When installing, the back ribs 29 are fitted onto the top of the column 26 through the connecting holes to fix the back ribs 29 and the column 26, thereby improving the stability of the back ribs 29.

[0054] At the same time, the outer side of the back rib 29 is connected to the extension of the cross brace by the stabilizing rod 27 to improve the stability of the formwork system.

[0055] Method 2: During the construction of pier 1, a protective concrete 32 of a certain thickness is poured on the outside of pier 1. A portal-shaped suspended formwork 31 is installed on the top of pier 1. The upper part of the suspended formwork 31 is used to define the area of ​​the zero block 14 to be poured, and the lower part of the suspended formwork 31 straddles the outside of the protective concrete 32. The lower panel of the suspended formwork 31 is fixed to the first anchor plate 2 and the second anchor plate 5 using temporary fixing rods 33.

[0056] The protective concrete 32 keeps the outer boundary of the pier 1 consistent with the boundary of the zero block 14, making it easy for the suspended formwork 31 to straddle.

[0057] Step 3: Pour block 014:

[0058] Pour concrete into block 0 (14), and remove the formwork and its support system after curing.

[0059] Step 4: Install the support for block 15:

[0060] The first connecting block 4 and the second connecting block 7 are connected by the first sleeve 3 and the second sleeve 6, respectively. The second sleeve 6 is also connected to a horizontal connecting cross brace 9. Vertical braces 10 are provided between adjacent longitudinal connecting cross braces 9. Support plates 11 and adjusting plates 12 are installed on several connecting cross braces 9 at the top. At the same time, multiple diagonal braces 8 connect the bottom connecting cross braces 9 to the first connecting block 4. The above-mentioned pier top platform is used as the support for block 15.

[0061] Step 5: Install bridge erecting machine 23:

[0062] Support legs 22 are installed on top of multiple completed zero blocks 14. The bridge erecting machine 23 is installed using the support legs 22. The lower support 18, vertical rod 20, reinforcing rod 19, and upper support 21 are respectively connected to both sides of the support legs 22. The top of the support legs 22 and the upper support 21 simultaneously support the bridge erecting machine 23, thereby improving the stability of the bridge erecting machine 23.

[0063] Step 6: Block 15 is in place:

[0064] The No. 1 block 15 is hoisted into place using the bridge erecting machine 23. The No. 1 block 15 is placed on the adjusting plate 12, the height of which can be linearly adjusted. The No. 1 block 15 is precisely positioned using the adjusting plate 12. The No. 1 block 15 is temporarily connected to the No. 0 block 14 using the connecting steel 17.

[0065] Step 7: Pour wet joint 16:

[0066] After the No. 1 block 15 is precisely positioned, the wet joint 16 between the No. 0 block 14 and the No. 1 block 15 is poured, and then the support system of the No. 1 block 15 is removed. The No. 0 block 14, the wet joint 16, and the No. 1 block 15 together constitute the pier top anchoring unit 13, which uses the pier top support as a working platform.

[0067] Step 8: Install the remaining prefabricated segments 25:

[0068] Except for block 14 and block 15, the remaining precast segments 25 are installed using a simultaneous suspension and segmented connection method. Multiple precast segments 25 in the same span are suspended and positioned separately using hanging rods 24. Each precast segment 25 is then connected to the previous segment and temporary prestress is applied. For example, blocks 2, 3, and 4 are connected to block 15 and temporary prestress is applied. Then blocks 5, 6, and 7 are connected to the previous segment and temporary prestress is applied, and so on. Multiple precast segments 25 are assembled and connected simultaneously, which improves assembly efficiency.

[0069] The parts not described in detail in this application are prior art, and therefore are not described in detail in this application.

[0070] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0071] Although this document uses a significant amount of technical terminology, the possibility of using other terms is not excluded. These terms are used merely to facilitate the description and explanation of the nature of this application; interpreting them as any additional limitation would be contrary to the spirit of this application.

[0072] This application is not limited to the above-described preferred embodiments. Anyone can derive other products in various forms under the guidance of this application. However, regardless of any changes made to their shape or structure, any technical solution that is the same as or similar to that of this application falls within the protection scope of this application.

Claims

1. A construction method for segmental precast single-box single-cell variable-height prestressed concrete box girders, characterized in that, The steps include the following: Step 1: Install embedded parts: When the bridge pier (1) is being poured, the upper first anchor plate (2) and the lower second anchor plate (5) are symmetrically installed near the top of the pier, and the first sleeve (3) and the second sleeve (6) are installed at intervals on the first anchor plate (2) and the second anchor plate (5). Step 2, Install the template of block 0 (14): Install the template and its support system of block 0 (14) using the embedded parts on the top of the pier; Step 3: Pour the concrete for block 0 (14): Pour the concrete for block 0 (14), and remove the formwork and its support system after curing. Step 4: Install the support for Block 1 (15): Connect the pier top platform using the embedded parts on the pier top, which serves as the support platform for Block 1 (15). Step 5: Install the bridge erecting machine (23): Install the support legs (22) on top of the multiple completed zero blocks (14), and use the support legs (22) to install the bridge erecting machine (23); Step 6, Positioning of Block 1 (15): Use the bridge erecting machine (23) to hoist Block 1 (15) into position, place Block 1 (15) on the adjusting plate (12), use the adjusting plate (12) to accurately position Block 1 (15), and use the connecting steel bar (17) to temporarily connect Block 1 (15) with Block 0 (14). Step 7, pouring the wet joint (16): After the No. 1 block (15) is precisely positioned, pour the wet joint (16) between the No. 0 block (14) and the No. 1 block (15), and then remove the support system of the No. 1 block (15); Step 8: Install the remaining precast segments (25): Except for block 0 (14) and block 1 (15), the remaining precast segments (25) are installed by simultaneous suspension and segmented connection to complete the construction.

2. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 1, characterized in that, In step 2, the installation method of the zero block (14) template and its support system is as follows: The second sleeve (6) is used to connect the connecting cross brace (9), the connecting cross brace (9) is used to install the second connecting block (7), and the second connecting block (7) is used to support and connect the upper template system. The connecting hole of the second connecting block (7) is fitted with a connecting component, and the mounting column (26) is fitted inside the second connecting block (7). The column (26) extends upward to the same elevation as the back rib (29). The second connecting block (7) is equipped with a support template (28) on top. The support template (28) is fixed by the spaced back ribs (29). The two support templates (28) and the back ribs (29) are pulled together by tie rods (30). When the back ribs (29) are installed, they are fitted onto the top of the column (26) through the connecting holes of the back ribs (29) to fix the back ribs (29) and the column (26). The outer side of the back brace (29) is connected to the extension of the cross brace using the stabilizing rod (27).

3. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 2, characterized in that, The second connecting block (7) is a square prefabricated block arranged at intervals, and the second connecting block (7) has multiple horizontal and vertical connecting holes.

4. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 1, characterized in that, In step 2, the installation method of the zero block (14) template and its support system is as follows: During the construction of the pier (1), a protective concrete (32) of a certain thickness is poured on the outside of the pier (1); The portal-shaped suspended formwork (31) is installed on the top of the pier (1). The upper part of the suspended formwork (31) is used to frame the area of ​​the zero block (14) to be poured, and the lower part of the suspended formwork (31) straddles the outside of the protective concrete (32). The lower panel of the suspended template (31) is fixed to the first anchor plate (2) and the second anchor plate (5) using temporary fixing rods (33); The outer boundary of the pier (1) is aligned with the boundary of the zero block (14) by using protective concrete (32).

5. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 1, characterized in that, In step 4: the installation method of the pier top platform is as follows: The first connecting block (4) and the second connecting block (7) are connected by the first sleeve (3) and the second sleeve (6) respectively. The second sleeve (6) is also connected to the horizontal connecting cross brace (9). Vertical supports (10) are provided between longitudinally adjacent connecting cross braces (9), and support plates (11) and adjustment plates (12) are installed on several connecting cross braces (9) at the top; The bottom connecting cross brace (9) is connected to the first connecting block (4) by multiple diagonal braces (8).

6. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 1, characterized in that, In step 5, the lower support (18), vertical rod (20), reinforcing rod (19) and upper support (21) are connected to both sides of the support leg (22). The top of the support leg (22) and the upper support (21) simultaneously support the bridge erecting machine (23), thereby improving the stability of the bridge erecting machine (23).

7. The construction method for segmental precast single-box single-cell variable-height prestressed concrete box girder according to claim 1, characterized in that, In step 6, the height of the adjustment plate (12) can be linearly adjusted. The bottom slope of block 1 (15) is adjusted by adjusting the adjustment plate (12) to adjust the positioning posture of the height-adjusting segment.

8. The construction method for segmental precast single-cell variable-height prestressed concrete box girder according to any one of claims 1-7, characterized in that, In step 8, multiple precast segments (25) are positioned simultaneously and sequentially assembled and connected with the preceding segment, and temporary prestress is applied to multiple precast segments (25) simultaneously.

9. The construction method for segmental precast single-cell variable-height prestressed concrete box girder according to any one of claims 1-7, characterized in that, Block 0 (14), wet joint (16), and Block 1 (15) together constitute the pier top anchoring unit (13), which uses the pier top support as a working platform.

10. A segmental precast single-box single-cell variable-height prestressed concrete box girder, characterized in that, The precast segmental precast single-box single-cell variable-height prestressed concrete box girder was constructed using the construction method described in any one of claims 1-9.

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