Construction method of strong composite steel-concrete composite beam without support

Abstract

The present invention provides a construction method for a non-support strong composite steel-concrete composite beam, comprising the following steps: providing a tool beam and a steel beam; the steel beam comprises a base, the left and right sides of the base are respectively connected with webs, and the top of each web is provided with a platform; installing the tool beam between the platforms on both sides of the steel beam, so that the tool beam and the steel beam are combined into an integral temporary steel truss beam; installing the temporary steel truss beam on the bridge pier; building a temporary steel formwork, the temporary steel formwork corresponds to the platform of the steel beam; the top of the temporary steel formwork and the top of the platform together constitute a casting surface; casting a concrete layer on the casting surface; after waiting for the strength and age of the concrete to reach the acceptance standard, removing the tool beam and the temporary steel formwork, leaving the combination of the steel beam and the concrete layer as the steel-concrete composite beam. In this application, the load before the concrete layer reaches the strength is borne by the temporary steel truss beam, and the tool beam is removed after the concrete layer reaches the strength, so that this part of the load is transferred to the steel-concrete composite beam.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, in particular to a construction method of a support-free strong composite steel-concrete composite beam. Background Art

[0002] In the prior art, there are two methods for constructing composite beams;

[0003] Solution 1: No-scaffold construction, first hoist the steel beam to the bridge pier, lay the steel formwork, and then directly pour the concrete layer, and the steel beam and concrete layer are combined into a steel-concrete composite beam; in this construction method, the dead weight of the concrete layer is entirely borne by the steel beam, and the concrete layer will not participate in the structural force of the composite beam before it hardens, so the concrete layer cannot bear the dead load of the composite beam itself, and can only bear the secondary dead load and live load, so it is called a weak composite beam;

[0004] Option 2: Supported by a bracket. The bracket is installed at the bottom of the steel beam, and the other end of the bracket is perpendicular to the ground. Then the steel formwork is laid and the concrete layer is poured. This construction method allows the weight of the concrete to be transferred from the steel beam to the bracket and then to the ground. The bracket is removed after the concrete layer hardens and forms strength. Therefore, the steel-concrete composite beam composed of the concrete layer and the steel beam bears its own constant load, so it is called a strong composite beam.

[0005] However, the disadvantages of these two construction methods are also very obvious;

[0006] Although the first scheme saves the amount of brackets, the concrete layer does not participate in the constant load of the composite beam, and the constant load is all borne by the steel beam. Therefore, the composite effect is poor, the amount of steel used is large, and the deflection required by the steel beam is also large. In order to achieve the same constant load effect, a larger pre-camber needs to be set;

[0007] Although the second scheme can save steel, it requires a large number of brackets, so the construction and disassembly process of the brackets will waste a lot of time and the construction cost is high. Especially in the construction of high-pier bridges, the required bracket height is higher and the disassembly and assembly are more cumbersome.

[0008] Therefore, there is an urgent need for a construction method for strong composite steel-concrete composite beams without support, which can achieve the effect of strong superposition of concrete and steel beams and reduce construction costs. Summary of the invention

[0009] In view of the shortcomings of the prior art, the present invention provides a construction method for a non-bracket strong composite steel-concrete composite beam. The technical solution adopted by the present invention is:

[0010] A construction method for a non-support strong composite steel-concrete composite beam comprises the following steps:

[0011] Step S1, providing a tool beam and a steel beam; the steel beam comprises a base, the left and right sides of the base are respectively connected with webs, and the top of each web is provided with a platform;

[0012] Step S2, installing a tool beam between the platforms on both sides of the steel beam, so that the tool beam and the steel beam are combined into an integral temporary steel truss beam;

[0013] Step S3, installing the temporary steel truss beam on the bridge pier;

[0014] Step S4, building a temporary steel formwork, wherein the temporary steel formwork corresponds to the platform of the steel beam; the top of the temporary steel formwork and the top of the platform together constitute a casting surface;

[0015] Step S5, pouring a concrete layer on the pouring surface;

[0016] Step S6, after waiting for the strength and age of the concrete to reach the acceptance standard, the tool beam and temporary steel formwork are removed, leaving the combination of the steel beam and the concrete layer, which is the steel-concrete composite beam.

[0017] Furthermore, the tool beam includes a longitudinal beam, a support body, a suspension rod, an upper fixing member, a lower fixing member and a cross beam; the number of longitudinal beams is two, and a plurality of cross beams are connected between the two longitudinal beams, and the plurality of cross beams are arranged at intervals in front and behind.

[0018] Furthermore, the tool beam is installed in the following manner: supporting bodies are placed on the front and rear ends of the platform respectively; then the longitudinal beam is placed on top of the two supporting bodies; a hanging rod is used to pass through the longitudinal beam, the supporting body, and the platform from top to bottom in sequence, a lower fixing piece is installed upward at the bottom of the hanging rod, and an upper fixing piece is installed downward at the top of the hanging rod; the lower fixing piece and the upper fixing piece work together to clamp the longitudinal beam, the supporting body, and the platform to complete the installation and fixation of the longitudinal beam.

[0019] Furthermore, multiple suspension rods are arranged at intervals between the ends of the longitudinal beam and the platform. The suspension rods are passed through the longitudinal beam and the platform from top to bottom in sequence. A lower fixing piece is installed upward at the bottom of the suspension rod, and an upper fixing piece is installed downward at the top of the suspension rod. The upper surface of the lower fixing piece is in contact with the lower surface of the platform, and the lower surface of the upper fixing piece is in contact with the upper surface of the longitudinal beam. The suspension rod is fixed by using the lower fixing piece and the upper fixing piece.

[0020] Furthermore, when the strong composite beam is hoisted and erected between two piers, the step S3 is specifically as follows: two hooks of the lifting crane are respectively hung on the cross beams at both ends of the tool beam in the longitudinal direction, and the lifting crane lifts the temporary steel truss beam onto the pier.

[0021] Furthermore, the disassembly method of the tool beam includes: first disassembling the lower fixing member and the upper fixing member, then pulling out the suspension rod, and removing the longitudinal beam and the support body in sequence.

[0022] Furthermore, when erecting a strong composite beam in a high pier or other place where it is inconvenient to hoist, the method further includes step S2.1: installing a guide beam at the front end of the longitudinal beam; and the step S3 is specifically as follows:

[0023] S3.1: Install the rear gun carriage at the rear end of the temporary steel truss beam, install the front gun carriage at the middle of the bottom of the temporary steel truss beam, and install the counterweight at the rear side of the top of the temporary steel truss beam;

[0024] S3.2: Push the temporary steel truss beam forward along the laid bridge (or roadbed) until the guide beam contacts the temporary pier column on the front pier 3;

[0025] S3.3: Remove the counterweight and front gun carriage;

[0026] S3.4: Continue to push the temporary steel truss beam until the front end of the steel beam moves to the fixed position of the front pier;

[0027] S3.5: Remove temporary piers and rear gun carriage, and lower beams.

[0028] Furthermore, the longitudinal beam extends forward to form a forward extension section, the top of the guide beam is connected to the bottom of the forward extension section, and the rear end of the guide beam is connected to the front end of the steel beam.

[0029] Furthermore, the disassembly method of the tool beam includes: first removing the guide beam, then removing the lower fixing member and the upper fixing member, pulling out the suspension rod, and removing the longitudinal beam and the support body in sequence.

[0030] Furthermore, during the installation of the hanger rod, a plastic sleeve is first placed at the reserved hole of the steel beam, and the hanger rod is installed so that it passes through the plastic sleeve.

[0031] Advantages of the present invention:

[0032] 1. Use temporary steel truss beams to participate in the load of the concrete layer before the concrete layer hardens to form strength. The load is borne by the tool beam and the steel beam together, which not only achieves the strong superposition effect of the concrete layer and the steel beam, but also omits the laying of the bracket and reduces the construction cost;

[0033] 2. The tool beam can be disassembled and recycled, which does not occupy the space at the bottom of the steel beam or the space under the bridge. It is not only convenient for disassembly and assembly, but also saves steel;

[0034] 3. The plastic sleeve prevents the tool boom from being hardened together with the concrete layer, which is convenient for disassembly of the tool boom. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a left view of step S2 of the present invention.

[0036] Figure 2 It is a front view of step S3 of the present invention.

[0037] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0038] Figure 4 It is a front view of step S4 of the present invention.

[0039] Figure 5 for Figure 4 Left side cross-sectional view.

[0040] Figure 6 It is a front view of step S5 of the present invention.

[0041] Figure 7 for Figure 6 Left side cross-sectional view.

[0042] Figure 8 This is a front view of step S2.1 of the present invention.

[0043] Fig. 9 This is a front view of step S3.1 of the present invention.

[0044] Fig.10 This is a front view of step S3.2 of the present invention.

[0045] Fig.11 This is a front view of step S3.3 of the present invention.

[0046] Fig.12 This is a front view of step S3.4 of the present invention.

[0047] Fig.13 This is a front view of step S3.5 of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] Please see attached Figure 1-7 The present invention provides a method for constructing a non-bracket strong composite steel-concrete composite beam, comprising the following steps:

[0050] Step S1, providing a tool beam 1 and a steel beam 2; the steel beam 2 comprises a base 201, and webs 202 are connected to the left and right sides of the base 201, respectively, and a platform 203 is provided on the top of each web 202;

[0051] Step S2, installing the tool beam 1 between the two side platforms 203 of the steel beam 2, so that the tool beam 1 and the steel beam 2 are combined into an integral temporary steel truss beam;

[0052] Step S3, installing the temporary steel truss beam on the bridge pier 3;

[0053] Step S4, constructing a temporary steel formwork 4, wherein the temporary steel formwork 4 corresponds to the platform 203 of the steel beam 2; the top of the temporary steel formwork 4 and the top of the platform 203 together constitute a casting surface;

[0054] Step S5, pouring a concrete layer 5 on the pouring surface;

[0055] Step S6, after waiting for the strength and age of the concrete to reach the acceptance standard, the tool beam 1 and the temporary steel formwork 4 are removed, leaving the combination of the steel beam 2 and the concrete layer 5 as the steel-concrete composite beam.

[0056] For the steel-concrete composite beam, the stress of the upper edge steel plate (i.e., platform 203) and the lower edge steel plate (i.e., base 201) at the mid-span position is the most important control point. The following table compares the stress of the steel beam in Scheme 1, Scheme 2 in the prior art and in this application using a 40-meter bridge as an example:

[0057]

[0058]

[0059] It can be seen from the above table that the stress of the upper and lower steel plates of the composite beam (i.e., the base 201 and the platform 203) is the control index in the design. The scheme (Scheme 3) of the present application is basically equivalent to the base stress of the scheme without support (Scheme 1), but the thickness of the steel plate in the compression zone of the platform can be saved by 1-55.2%=44.8%, and the compression index of the concrete is increased to 200% of the original; in short, the compression resistance of concrete is more cheaply replaced by the compression resistance of steel materials to achieve economy.

[0060] The temporary steel truss beam is used to participate in the load of the concrete layer 5 before the concrete layer 5 hardens and forms strength. The load is borne by the tool beam 1 and the steel beam 2 together, which not only achieves the strong superposition effect of the concrete layer 5 and the steel beam 2, but also omits the laying of the bracket, reducing the construction cost;

[0061] At the same time, since the tool beam 1 shares the load of the concrete layer 5, the thickness of the platform 203 can be appropriately reduced, saving the amount of steel.

[0062] In this embodiment, the longitudinal beam 101 is an I-beam or a box beam.

[0063] Please see attached Figure 1 Or 3, in this embodiment, the tool beam 1 includes a longitudinal beam 101, a support body 102, a suspension rod 103, a lower fixing member 104, an upper fixing member 105 and a cross beam 106; the number of longitudinal beams 101 is two, and a plurality of cross beams 106 are connected between the two longitudinal beams 101, and the plurality of cross beams 106 are arranged at intervals in the front and rear.

[0064] The tool beam 1 is installed in the following manner: support bodies 102 are placed at the front and rear ends of the platform 203 respectively; then the longitudinal beam 101 is placed on top of the two support bodies 102; a suspension rod 103 is used to pass through the longitudinal beam 101, the support body 102, and the platform 203 from top to bottom in sequence, a lower fixing piece 104 is installed upward at the bottom of the suspension rod 103, and an upper fixing piece 105 is installed downward at the top of the suspension rod 103, and the lower fixing piece 104 and the upper fixing piece 105 work together to clamp the longitudinal beam 101, the support body 102 and the platform 203 to complete the installation and fixation of the longitudinal beam 101; the support body 102 plays the role of supporting the longitudinal beam 101, and the support body 102, the suspension rod 103 and the longitudinal beam 101 can all be disassembled and recycled, and do not occupy the space at the bottom of the steel beam 2, nor do they occupy the space under the bridge. Not only is it convenient to disassemble and assemble, but it can also save steel.

[0065] In order to enhance the stability of the longitudinal beam 101 and facilitate torque transmission, a plurality of hangers 103 are arranged at intervals between the two ends of the longitudinal beam 101 and the platform 203. The hangers 103 are passed through the longitudinal beam 101 and the platform 203 from top to bottom in sequence. A lower fixing member 104 is installed upward at the bottom of the hanger 103, and an upper fixing member 105 is installed downward at the top of the hanger 103. The upper surface of the lower fixing member 104 contacts the lower surface of the platform 203, and the lower surface of the upper fixing member 105 contacts the upper surface of the longitudinal beam 101. The hanger 103 is fixed by the lower fixing member 104 and the upper fixing member 105. During the hardening process of the concrete layer 5, the stress is transferred from the hanger 103 to the longitudinal beam 101.

[0066] In one embodiment, the lower fixing member 104 and the upper fixing member 105 are both nuts; in another embodiment, the lower fixing member 104 and the upper fixing member 105 are both clamps.

[0067] Please see attached Figure 2 and 3 In one embodiment, when the strong composite beam is hoisted and erected between two piers, the step S3 is specifically as follows: the two hooks of the lifting machine are respectively hung on the crossbeams 106 at both ends of the tool beam 1, and the lifting machine lifts the temporary steel truss beam to the pier 3; in the prior art, the lifting is generally performed by hanging the hooks on both ends of the hanging parts, and then the hanging parts are lifted by the crane; if only the steel beam 2 is hoisted to the pier 3 and then the tool beam 1 is installed, the two ends of the steel beam 2 are subjected to upward tension during the lifting process, and the steel beam 2 bends and deforms due to its own low rigidity; but after the tool beam 1 is installed, the temporary steel truss beam greatly improves the rigidity of the original steel beam, and the deformation of the steel beam 2 can be reduced during the lifting process, so the steel beam 2 no longer needs to be set with a large deflection and pre-arch, reducing the amount of steel used and the amount of lifting deformation;

[0068] In this embodiment, the disassembly method of the tool beam 1 includes: first disassembling the lower fixing member 104 and the upper fixing member 105, then pulling out the suspension rod 103, and then removing the longitudinal beam 101 and the support body 102 in sequence.

[0069] In another embodiment, when erecting a strong composite beam in a high pier or other place where it is inconvenient to hoist, as shown in the attached Figure 8 As shown, the method further includes step S2.1: installing the guide beam 107 at the front end of the longitudinal beam 101; Figure 9-13 As shown, the step S3 is specifically as follows:

[0070] S3.1: Install the rear gun carriage 6 at the rear end of the temporary steel truss beam, install the front gun carriage 7 at the middle of the bottom of the temporary steel truss beam, and install the counterweight 8 at the rear side of the top of the temporary steel truss beam;

[0071] S3.2: Push the temporary steel truss beam forward along the already laid bridge (or roadbed) until the guide beam 107 contacts the temporary pier 9 on the front pier 3;

[0072] S3.3: Remove the counterweight 8 and the front gun carriage 7;

[0073] S3.4: Continue to push the temporary steel truss beam until the front end of the steel beam 2 moves to the fixed position of the front pier 3;

[0074] S3.5: Remove temporary pier 9 and rear gun carriage 6, and lower beams.

[0075] For details, please refer to the attached Figure 8 In step S2.1, the longitudinal beam 101 extends forward to form a forward extension section, the top of the guide beam 107 is connected to the bottom of the forward extension section, and the rear end of the guide beam 107 is connected to the front end of the steel beam 2;

[0076] When the guide beam 107 is connected to the longitudinal beam 101 , the forward extension section of the longitudinal beam 101 is used as a connection carrier, which can improve the rigidity of the entire temporary steel truss beam and reduce the stress deformation of the steel beam 2 .

[0077] In this embodiment, the disassembly method of the tool beam 1 includes: first removing the guide beam 107, then removing the lower fixing member 104 and the upper fixing member 105, pulling out the suspension rod 103, and removing the longitudinal beam 101 and the support body 102 in sequence.

[0078] As an embodiment of the present application, the support body 102 is an I-beam support body or a box-type support body.

[0079] Please see attached Figure 5 In one embodiment, during the installation of the hanger 103, a plastic sleeve 108 is first placed at the reserved hole of the steel beam 2, and the hanger 103 is installed so that the hanger 103 passes through the plastic sleeve 108; the plastic sleeve 108 prevents the hanger 103 from being hardened together with the concrete layer 5, which is conducive to the disassembly of the hanger 103.

[0080] To summarize, this application uses temporary steel truss beams to participate in the load of the concrete layer before the concrete layer hardens to form strength. The load is shared by the tool beam and the steel beam, which not only achieves a strong superposition effect between the concrete layer and the steel beam, but also omits the laying of the bracket, reducing construction costs; it can be partially disassembled, recycled, and reused.

[0081] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A construction method for a non-support strong composite steel-concrete composite beam, characterized in that: The steps include: Step S1, providing a tool beam and a steel beam; the steel beam comprises a base, the left and right sides of the base are respectively connected with webs, and the top of each web is provided with a platform; Step S2, installing a tool beam between the platforms on both sides of the steel beam, so that the tool beam and the steel beam are combined into an integral temporary steel truss beam; Step S3, installing the temporary steel truss beam on the bridge pier; Step S4, building a temporary steel formwork, wherein the temporary steel formwork corresponds to the platform of the steel beam; the top of the temporary steel formwork and the top of the platform together constitute a casting surface; Step S5, pouring a concrete layer on the pouring surface; Step S6, after waiting for the strength and age of the concrete to reach the acceptance standard, the tool beam and temporary steel formwork are removed, leaving the combination of the steel beam and the concrete layer, which is the steel-concrete composite beam.

2. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 1, characterized in that: The tool beam comprises a longitudinal beam, a supporting body, a suspension rod, an upper fixing member, a lower fixing member and a cross beam; there are two longitudinal beams, a plurality of cross beams are connected between the two longitudinal beams, and the plurality of cross beams are arranged at intervals in front and back.

3. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 2, characterized in that: The tool beam is installed in the following manner: supporting bodies are placed on the front and rear ends of the platform respectively; then the longitudinal beam is placed on top of the two supporting bodies; a hanging rod is used to pass through the longitudinal beam, the supporting body, and the platform from top to bottom in sequence, a lower fixing piece is installed upward at the bottom of the hanging rod, and an upper fixing piece is installed downward at the top of the hanging rod; the lower fixing piece and the upper fixing piece work together to clamp the longitudinal beam, the supporting body, and the platform to complete the installation and fixation of the longitudinal beam.

4. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 3 is characterized in that: A plurality of suspension rods are arranged at intervals between the ends of the longitudinal beam and the platform. The suspension rods are passed through the longitudinal beam and the platform from top to bottom in sequence. A lower fixing piece is installed upward at the bottom of the suspension rod, and an upper fixing piece is installed downward at the top of the suspension rod. The upper surface of the lower fixing piece contacts the lower surface of the platform, and the lower surface of the upper fixing piece contacts the upper surface of the longitudinal beam. The suspension rod is fixed by using the lower fixing piece and the upper fixing piece.

5. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 3 or 4, characterized in that: When the strong composite beam is hoisted and erected between two piers, the step S3 is specifically as follows: two hooks of the lifting crane are respectively hung on the cross beams at both ends of the tool beam in the longitudinal direction, and the lifting crane lifts the temporary steel truss beam onto the pier.

6. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 3 or 4, characterized in that: The disassembly method of the tool beam includes: first disassembling the lower fixing member and the upper fixing member, then pulling out the suspension rod, and sequentially removing the longitudinal beam and the supporting body.

7. The construction method of the non-support strong composite steel-concrete composite beam according to claim 3 is characterized in that: When erecting a strong composite beam in a high pier or other place where it is inconvenient to hoist, the method further includes step S2.1: installing a guide beam at the front end of the longitudinal beam; the step S3 is specifically as follows: S3.1: Install the rear gun carriage at the rear end of the temporary steel truss beam, install the front gun carriage at the middle of the bottom of the temporary steel truss beam, and install the counterweight at the rear side of the top of the temporary steel truss beam; S3.2: Push the temporary steel truss beam forward along the already laid bridge (or roadbed) until the guide beam contacts the temporary pier on the bridge pier in front; S3.3: Remove the counterweight and front gun carriage; S3.4: Continue to push the temporary steel truss beam until the front end of the steel beam moves to the fixed position of the front pier; S3.5: Remove temporary piers and rear gun carriage, and lower beams.

8. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 7, characterized in that: The longitudinal beam extends forward to form a forward extension section, the top of the guide beam is connected to the bottom of the forward extension section, and the rear end of the guide beam is connected to the front end of the steel beam.

9. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 7 or 8, characterized in that: The disassembly method of the tool beam includes: first removing the guide beam, then removing the lower fixing member and the upper fixing member, pulling out the suspension rod, and sequentially removing the longitudinal beam and the supporting body.

10. The method for constructing a non-support strong composite steel-concrete composite beam according to claim 3, characterized in that: During the installation of the hanger, first place a plastic sleeve at the reserved hole of the steel beam, and then install the hanger so that it passes through the plastic sleeve.

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