Construction method for in-situ assembly of single-wall steel hanging box cofferdam

Abstract

The invention provides a construction method for in-situ assembly of a single-wall steel hanging box cofferdam, a telescopic and hanging cross-shaped beam assembly is used as an assembly bracket, the cross-shaped beam assembly comprises a cross-shaped main beam body formed in a cross-shaped crossing mode, and four branches of the cross-shaped main beam body form guide sleeves respectively; each group of cross-shaped main beam bodies is provided with a plurality of guide sleeves, a telescopic beam piece is arranged in each guide sleeve in a sliding and sleeved mode, each telescopic beam piece can retract or stretch out of the corresponding guide sleeve in the branch extension direction, each group of cross-shaped main beam bodies are installed in the corresponding steel casings, and holes allowing the telescopic beam pieces to stretch out and draw back are formed in the steel casings. And the cross-shaped main beam body is supported and fixed by a bearing bracket which is welded and fixed on the inner wall of the steel casing. The telescopic cross-shaped beam is used as the in-situ assembly bracket of the single-wall steel hanging box cofferdam, the cross-shaped beam is used for a cofferdam hanging system in the later period, one structure has two purposes, the structure is safe and reliable, the problem that the bracket is difficult to cut off after cofferdam assembly is completed is solved, the construction difficulty is small, and the construction period and the cost are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering construction, and in particular relates to a construction method for in-situ assembly of a single-wall steel hanging box cofferdam. Background Art

[0002] With the increasing number of offshore bridge construction projects in my country, the construction difficulty of the foundation of the pier in the sea area has increased. It is particularly important to use cofferdams as temporary structures to form a waterless environment to construct the pier. In the previous underwater pier construction, the commonly used cofferdam structures include steel plate (tube) pile cofferdams, steel box cofferdams, steel hanging box cofferdams, etc. The common practice of steel hanging box cofferdams is to use floating cranes to hoist and lower them as a whole. However, when the navigation in the waters where the pier is located is restricted and there is no suitable floating crane available, it is necessary to weld and assemble the brackets on the steel casing of the pier pier to assemble the hanging box cofferdam in situ. After the cofferdam is assembled, the assembled brackets need to be cut off, and then the cofferdam is lowered into place using the lifting and lowering system. However, under the above conditions, since it is time-consuming to cut off the assembled brackets, it takes up construction period and resources. Therefore, it is necessary to improve the existing deep-water bridge pier cofferdam construction technology. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides the following technical solutions:

[0004] A construction method for in-situ assembly of a single-wall steel hanging box cofferdam, using a retractable and suspended cross beam assembly as an assembly bracket, the cross beam assembly includes a cross main beam body formed in a cross shape, four branches of the cross main beam body respectively form guide sleeves, each guide sleeve is provided with a telescopic beam member in a sliding sleeve, each telescopic beam member can be retracted or extended out of the guide sleeve along the extension direction of the branch, each group of cross main beam bodies is installed in a corresponding steel casing, the cross center of the cross main beam body is located on the axis line of the steel casing, the telescopic direction of each telescopic beam member is located in the radial direction of the steel casing, holes are opened on the steel casing for the telescopic beam members to extend and pass through, and the ends of each branch of the cross main beam body are supported and fixed by supporting brackets welded and fixed to the inner wall of the steel casing.

[0005] Further, the following steps are included:

[0006] S1. Connect high steel casing, weld supporting brackets and bracing brackets, install cross beam components, assemble and install bottom keel and bottom plate assembly;

[0007] S2, assemble the wall panels, install the ring beam and the inner support, connect and fix the wall panels with the bottom keel and the bottom plate assembly, and install the wall panel guide;

[0008] S3. Weld the bottom end of the suspension system's hanger rod and the lifting lugs of the lifting and lowering system onto the bottom keel and bottom plate assembly, and install the lifting and lowering system;

[0009] S4. The cofferdam is lifted as a whole through the lifting and lowering system, the supporting corbels are cut off, and the telescopic beams of the cross beam assembly are pushed and retracted as a whole into the steel casing;

[0010] S5. Lower the cofferdam as a whole, extend the telescopic beam and fix the top of the suspension system boom to it, then lower the cofferdam to the designed elevation to complete the suspension system conversion;

[0011] S6. Remove the lifting and lowering system, cut off the lifting ears on the bottom keel and the bottom plate assembly, install the blocking plate on the bottom keel and the bottom plate assembly, and pour the first layer of bottom sealing concrete;

[0012] S7. After the first layer of bottom seal concrete reaches the design strength, drain the water in the cofferdam, weld an anti-sinking corbel on the upper surface of the first layer of bottom seal concrete on the steel casing, weld the anti-sinking corbel to the suspension system hanger, pour a second layer of bottom seal concrete on the first layer of bottom seal concrete, and bury the anti-sinking corbel in the second layer of bottom seal concrete;

[0013] S8. After the second layer of bottom concrete reaches the design strength, remove the cross beam assembly, cut off the hanging system hanger rod body, wall panel guide and steel casing body located above the second layer of bottom concrete, tie the first layer of pedestal reinforcement on the second layer of bottom concrete and cast the first layer of pedestal.

[0014] Further, in S1, after the bored pile construction is completed, the steel casing of the lifting and lowering system is connected to the designed top elevation, the drilling platform within the cofferdam is removed, and supporting brackets are welded on the steel casings located on the surrounding periphery. Supporting brackets for supporting and fixing the cross beam assembly are welded in each steel casing, and the cross beam assembly is installed in each steel casing and supported and fixed by the supporting brackets. Holes are opened in the steel casing, and each telescopic beam member of the cross beam assembly can extend through the steel casing from the corresponding holes to serve as an assembly bracket or be retracted into the steel casing as a whole. The bottom keel and the bottom plate are processed in blocks and transported to the site, and then assembled and installed on the telescopic beam members and the cross main beam body in the extended state.

[0015] Further, in S2, the wall panels are transported to the site after being processed in the factory, and the wall panels, ring beams, internal supports and connection systems are assembled on the corbel system composed of the cross beam assembly and the supporting corbels, and the bottom keel and bottom plate assembly using lifting equipment. The wall panels are fixed to the bottom keel and bottom plate assembly with bolts, and the wall panel guides are installed.

[0016] Furthermore, in S5, the lifting and lowering system is used to lower the cofferdam as a whole to 2m below the position of the cross beam assembly, and the telescopic beams are pulled out to extend out of the steel casing to serve as assembly brackets again. The top of the suspension system boom is stuck in the boom hole of the corresponding telescopic beam of the cross beam assembly and fixed by the connecting piece, and then the cofferdam is lowered to the design elevation. At this time, the top of the suspension system boom is hung on the cross beam assembly, and the suspension system conversion is completed.

[0017] Furthermore, it also includes S9, after the concrete of the first layer of the pedestal reaches the design strength, the lower ring beam, internal support and upper and lower ring beams, the hangers and connecting systems between the ring beams are removed when the water level is low, and the second layer of the pedestal reinforcement is tied on the first layer of the pedestal and the second layer of the pedestal is cast.

[0018] Furthermore, it also includes S10, after the second-layer pedestal concrete reaches the design strength, the second-layer ring beam and internal support are removed; the pier body steel bars are tied and the pier body is cast on the second-layer pedestal, and the upper structure construction begins.

[0019] The present invention uses a retractable cross beam as an in-situ assembly bracket for a single-wall steel hanging box cofferdam, and later uses the cross beam in a cofferdam hanging system, so that one structure has two uses and the structure is safe and reliable. The problem of cutting off the assembly bracket after the cofferdam is assembled is overcome, the construction difficulty is small, and the construction period and cost are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings that constitute a part of the present invention are used to provide further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a structural schematic diagram related to step S1;

[0022] Figure 2 It is a structural schematic diagram related to step S2;

[0023] Figure 3 It is a structural schematic diagram related to step S3;

[0024] Figure 4 It is a structural schematic diagram related to step S4;

[0025] Figure 5 It is a structural schematic diagram related to step S5;

[0026] Figure 6 It is a structural schematic diagram related to step S6;

[0027] Figure 7 is a schematic structural diagram related to step S7;

[0028] Figure 8 It is a structural schematic diagram related to step S8;

[0029] Fig. 9 It is a structural schematic diagram related to step S9;

[0030] Fig.10It is a structural schematic diagram related to step S10;

[0031] Fig.11 is a schematic top view related to step S2;

[0032] Fig.12 for Fig.11 Enlarged schematic diagram of part A.

[0033] Reference numerals in the figure: 1, steel casing; 2, supporting corbel; 3, casing reinforcement plate;

[0034] 4. Cross beam assembly; 41. Cross main beam body; 41a. Horizontal main beam; 41b. Longitudinal main beam; 42. Telescopic beam; 421. Hanging rod hole; 422. Connecting piece; 43. Connecting sleeve;

[0035] 5. Supporting corbel; 6. Bottom keel and bottom plate assembly; 7. Wall panel; 8. Ring beam; 9. Internal support; 10. Wall panel guide; 11. Hanger between ring beams; 12. Hanging system hanger; 13. Lifting lug; 14. Lifting and lowering system; 15. Bottom plate blocking plate; 16. First layer of bottom sealing concrete; 17. Anti-sinking corbel; 18. Second layer of bottom sealing concrete. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] In the description of the embodiments of the present invention, it should be noted that the indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the application product is usually placed when in use, or is the orientation or position relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention or simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] The term "plurality" in the present invention refers to more than two (including two). The terms "first", "second", etc. are only used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0039] Unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0040] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0041] The present invention utilizes a retractable and hanging cross beam assembly as an assembly bracket, which is suitable for the construction of a single-wall steel hanging box cofferdam assembled in situ, and includes the following steps:

[0042] S1, connect the high steel casing 1, weld the supporting bracket 2, the supporting bracket 5, install the cross beam assembly 4, assemble and install the bottom keel and bottom plate assembly 6;

[0043] More specifically, Figure 1 As shown, in S1, after the bored pile construction is completed, the steel casing 1 of the lifting and lowering system is connected to the designed top elevation, the drilling platform within the cofferdam range is removed, and the supporting brackets 5 are welded on the steel casings located on the surrounding periphery. The supporting brackets 2 for supporting and fixing the cross beam assembly 4 are welded in each steel casing 1 (casing reinforcement plates can also be added at necessary locations), the cross beam assembly is installed in each steel casing 1 and supported and fixed by the supporting brackets 2, and holes are opened in the steel casing. Each telescopic beam member 42 of the cross beam assembly 4 can extend through the corresponding holes through the steel casing to serve as an assembled bracket or be retracted into the steel casing as a whole. The bottom keel and the bottom plate are processed in blocks and transported to the site, and assembled and installed on the telescopic beam member 42 in the extended state and the cross main beam body.

[0044] Combination Fig.11 and Fig.12 As shown, the cross beam assembly 4 includes a cross main beam body 41 which is composed of a cross main beam 41a and a longitudinal main beam 41b. The four branches of the cross main beam body 41 respectively form guide sleeves. A telescopic beam member 42 is slidably sleeved in each guide sleeve. Each telescopic beam member 42 can be retracted or extended out of the guide sleeve along the extension direction of the branch. Each group of cross main beam bodies 41 is installed in the corresponding steel casing 1, so that the cross center of the cross main beam body 41 is located on the axis line of the steel casing 1, and the telescopic direction of each telescopic beam member 42 is equivalent to being located in the radial direction of the steel casing 1. The steel casing is provided with holes for the telescopic beam member 42 to extend and pass through, and the end portions of each branch of the cross main beam body 41 are supported and fixed by supporting brackets 2 welded and fixed to the inner wall of the steel casing 1.

[0045] The cross main beam body 41 can be formed by pre-opening a through hole in the middle of a main beam (for example, the transverse main beam 41a), and then passing another main beam (for example, the longitudinal main beam 41b) through the through hole to form a cross of two main beams, and then fixing the two main beams by welding, and then inserting the four telescopic beam members 42 into the corresponding guide sleeves and keeping them in a retracted state, and then hoisting the cross beam assembly 4 as a whole into the corresponding elevation position in the steel casing, with the openings of each branch (guide sleeve) aligned with the corresponding holes on the steel casing 1, and supporting the cross main beam body 41 with two supporting brackets welded and fixed in advance at the holes on the inner wall of the steel casing to support and fix it in the steel casing.

[0046] S2, assemble the wall panel 7, install the ring beam 8 and the inner support 9, connect and fix the wall panel 7 with the bottom keel and the bottom plate assembly 6, and install the wall panel guide 10;

[0047] More specifically, Figure 2 As shown, after the wall panels are processed in the factory, they are transported to the site, and the wall panels 7, ring beams 8, inner supports 9 and connection systems are assembled on the corbel system composed of the cross beam assembly and the supporting corbel 5, as well as the bottom keel and bottom plate assembly 6 using lifting equipment. The wall panels 8 are fixed to the bottom keel and bottom plate assembly 6 by bolts, and the wall panel guides 10 are installed.

[0048] S3, welding the suspension system hanger 12 and the lifting lug 13 of the lifting and lowering system on the bottom keel, and installing the lifting and lowering system 14;

[0049] More specifically, Figure 3 As shown, the bottom end of the suspension system hanger 12 and the lifting lug 13 of the lifting and lowering system are welded and fixed on the bottom keel and bottom plate assembly 6, and the lifting and lowering system 14 is installed.

[0050] S4, the cofferdam is lifted as a whole by the lifting and lowering system 14, the supporting corbels 5 are cut off, and the telescopic beams 42 of the cross beam assembly 4 are pushed and retracted as a whole into the steel casing 1;

[0051] More specifically, Figure 4 As shown, the cofferdam is lifted as a whole by 1.5 m through the lifting and lowering system, the supporting bracket 5 on the steel casing is cut off, and the telescopic beam 42 of the cross beam assembly 4 is pushed and retracted into the steel casing 1 as a whole.

[0052] S5, lower the cofferdam as a whole, extend the telescopic beam 42 and fix the top of the suspension system boom 12 to it, and then lower the cofferdam to the designed elevation to complete the suspension system conversion;

[0053] More specifically, Figure 5 As shown, the cofferdam is lowered as a whole to 2m below the position of the cross beam assembly 4 by using the lifting and lowering system, and each telescopic beam 42 is pulled out to extend out of the steel casing to serve as an assembly bracket again. The top of the suspension system hanger 12 is stuck in the hanger hole 421 of the corresponding telescopic beam 42 of the cross beam assembly and fixed by the connecting piece 422. Then the cofferdam is lowered to the designed elevation. At this time, the top of the suspension system hanger 12 is hung on the cross beam assembly, and the suspension system conversion is completed.

[0054] S6, such as Figure 6 As shown, the lifting and lowering system is dismantled, the lifting lugs 13 on the bottom keel and bottom plate assembly 6 are cut off, a blocking plate is installed on the bottom keel and bottom plate assembly 6, and the first layer of bottom sealing concrete 16 is poured.

[0055] S7, such as Figure 7As shown, after the first layer of bottom seal concrete 16 reaches the design strength, the water in the cofferdam is drained at low tide, and the anti-sinking corbel 17 is welded on the upper surface of the first layer of bottom seal concrete 16 on the steel casing 1, and the anti-sinking corbel 17 is welded to the suspension system suspender 12, and the second layer of bottom seal concrete 18 is poured on the first layer of bottom seal concrete 16, and the second layer of bottom seal concrete 18 buries the anti-sinking corbel 17;

[0056] S8, such as Figure 8 As shown, after the second layer of bottom concrete 18 reaches the designed strength, the cross beam assembly 4 is removed, the suspension system hanger 12 rod body, the wall panel guide and the steel casing body located above the second layer of bottom concrete 18 are cut off, and the first layer of pedestal reinforcement is tied on the second layer of bottom concrete 18 and the first layer of pedestal is cast.

[0057] S9, such as Fig. 9 As shown, after the concrete of the first layer of the pedestal reaches the design strength, the lower ring beam, inner support, upper and lower ring beams, the suspender 11 between the ring beams and the connection system are removed when the water level is low, and the second layer of the pedestal reinforcement is tied on top of the first layer of the pedestal and the second layer of the pedestal is cast.

[0058] S10, such as Fig.10 As shown, after the second-layer cap concrete reaches the designed strength, the second-layer ring beam and internal support are removed; the pier body reinforcement is tied on top of the second-layer cap and the pier body is cast, and the upper structure construction begins.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for in-situ assembly of a single-wall steel hanging box cofferdam, characterized in that: A retractable and hanging cross beam assembly is used as an assembly bracket. The cross beam assembly (4) includes a cross main beam body (41) formed in a cross shape. The four branches of the cross main beam body respectively form guide sleeves. A telescopic beam member (42) is slidably sleeved in each guide sleeve. Each telescopic beam member can be retracted or extended out of the guide sleeve along the extension direction of the branch. Each group of cross main beam bodies is installed in a corresponding steel casing (1) so that the cross center of the cross main beam body is located on the axial line of the steel casing. The telescopic direction of each telescopic beam member is located in the radial direction of the steel casing. Holes are opened on the steel casing for the telescopic beam member to extend and pass through. The ends of each branch of the cross main beam body are supported and fixed by supporting brackets welded and fixed to the inner wall of the steel casing.

2. The construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 1, characterized in that: The following steps are involved: S1. Connect high steel casing, weld supporting brackets and bracing brackets, install cross beam components, assemble and install bottom keel and bottom plate assembly; S2, assemble the wall panels, install the ring beam and the inner support, connect and fix the wall panels with the bottom keel and the bottom plate assembly, and install the wall panel guide; S3. Weld the bottom end of the suspension system's hanger rod and the lifting lugs of the lifting and lowering system onto the bottom keel and bottom plate assembly, and install the lifting and lowering system; S4. The cofferdam is lifted as a whole through the lifting and lowering system, the supporting corbels are cut off, and the telescopic beams of the cross beam assembly are pushed and retracted as a whole into the steel casing; S5. Lower the cofferdam as a whole, extend the telescopic beam and fix the top of the suspension system boom to it, then lower the cofferdam to the designed elevation to complete the suspension system conversion; S6. Remove the lifting and lowering system, cut off the lifting ears on the bottom keel and the bottom plate assembly, install the blocking plate on the bottom keel and the bottom plate assembly, and pour the first layer of bottom sealing concrete; S7. After the first layer of bottom seal concrete reaches the design strength, drain the water in the cofferdam, weld an anti-sinking corbel on the upper surface of the first layer of bottom seal concrete on the steel casing, weld the anti-sinking corbel to the suspension system hanger, pour a second layer of bottom seal concrete on the first layer of bottom seal concrete, and bury the anti-sinking corbel in the second layer of bottom seal concrete; S8. After the second layer of bottom concrete reaches the design strength, remove the cross beam assembly, cut off the hanging system hanger rod body, wall panel guide and steel casing body located above the second layer of bottom concrete, tie the first layer of pedestal reinforcement on the second layer of bottom concrete and cast the first layer of pedestal.

3. A construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 2, characterized in that: In S1, after the bored pile construction is completed, the steel casing of the lifting and lowering system is connected to the designed top elevation, the drilling platform within the cofferdam is removed, and supporting brackets are welded on the steel casings located on the surrounding periphery. Supporting brackets for supporting and fixing the cross beam assembly are welded in each steel casing. The cross beam assembly is installed in each steel casing and supported and fixed by the supporting brackets. Holes are opened on the steel casing, and each telescopic beam member of the cross beam assembly can extend through the steel casing from the corresponding holes to serve as an assembly bracket or retract into the steel casing as a whole. The bottom keel and the bottom plate are processed in blocks and transported to the site, and assembled and installed on the telescopic beam members and the cross main beam body in the extended state.

4. The construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 2, characterized in that: In S2, the wall panels are transported to the site after being processed in the factory. The wall panels, ring beams, internal supports and connection systems are assembled on the corbel system composed of the cross beam assembly and the supporting corbels, as well as the bottom keel and bottom plate assembly using lifting equipment. The wall panels are fixed to the bottom keel and bottom plate assembly with bolts, and the wall panel guides are installed.

5. The construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 2, characterized in that: In S5, the lifting and lowering system is used to lower the cofferdam as a whole to 2m below the position of the cross beam assembly, and the telescopic beams are pulled out to extend out of the steel casing to serve as assembly brackets again. The top of the suspension system boom is stuck in the boom hole of the corresponding telescopic beam of the cross beam assembly and fixed by the connecting piece. Then the cofferdam is lowered to the design elevation. At this time, the top of the suspension system boom is hung on the cross beam assembly, completing the conversion of the suspension system.

6. The construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 2, characterized in that: It also includes S9, after the concrete of the first layer of pedestal reaches the design strength, the lower ring beam, inner support, upper and lower ring beams, hangers and connecting systems are removed when the water level is low, the second layer of pedestal reinforcement is tied on the first layer of pedestal and the second layer of pedestal is cast.

7. A construction method for in-situ assembly of a single-wall steel hanging box cofferdam as claimed in claim 6, characterized in that: It also includes S10. After the second-layer pedestal concrete reaches the design strength, the second-layer ring beam and internal support are removed; the pier body steel bars are tied and the pier body is cast on the second-layer pedestal, and the upper structure construction begins.

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