CN111851318A - Side span formwork system of cantilever bridge and its construction method - Google Patents

Abstract

The invention discloses a side span formwork system of a cantilever bridge and a construction method thereof, and belongs to the technical field of bridge construction. Pre-embedded steel plates are arranged on the top of side span buttresses, support frames are welded and installed on the embedded steel plates, and adjacent support frames are arranged between adjacent support frames. Strengthen the bracing, install temporary fixed piers, top longitudinal beams, support longitudinal beams, rear upper beams, rear lower beams and front beams between the support frame and the poured bridge section, and set up a horizontal distribution beam on the bottom longitudinal beam; the bottom formwork is mainly laid On the horizontal distribution beam, the other part is laid between the support frame and the permanent support, supported by the inner temporary support, the outer mold support is set on the support longitudinal beam, and the flange bottom mold and the outer mold are set on the outer mold support, respectively. By fixing the tie rods, the bottom mold is installed with an inner mold, and the top support frame of the side span pier and the poured bridge section are used as the gravity support structure for the construction of the side span closing section of the cantilever bridge, which reduces the hoisting workload and thus reduces the construction period. and cost.

Description

Side span formwork system of cantilever bridge and its construction method

technical field

The invention belongs to the technical field of bridge construction, in particular to a side span formwork system of a cantilever bridge and a construction method thereof.

Background technique

With the continuous development of my country's social economy, bridge construction has entered a period of rapid development. Today's road and bridge construction investment scale is increasing, the relevant construction technology level is getting higher and higher, and the structural complexity is gradually deepening. The cantilever girder bridge refers to a girder bridge in which a simply supported beam with one or both ends freely suspended outwards is used as the main load-bearing member of the upper structure. Cantilever girder bridges are generally statically indeterminate structures, and the internal force of the structure is not affected by the deformation of the foundation, and the requirements for the foundation are low. In a porous bridge, only one support needs to be set on the pier, which reduces the size of the pier accordingly and saves the material consumption of the foundation engineering, so it is widely used in bridge construction.

Cantilever girder bridges are not easy to adopt prefabricated construction. When pouring large-span cantilever bridges, we usually use the method of hanging baskets to perform segmented cantilever operations on site. For example, in the construction of the side span closed section, the existing patent CN103556578B uses the side span pier top and the hanging basket as the gravity support structure for the cantilever pouring of the continuous beam straight line section and the side span closed section, instead of erecting the side span cast-in-place on the ground. The bracket acts as the gravity support structure for its concrete works. However, this patent only states how to support the outer mold, but does not specify how to support the inner mold. For the support of the inner mold, it is common to erect a complex hanging basket system, which is expensive, cumbersome and slow. Pouring on top.

Therefore, it is very important to find a cantilever bridge side span formwork system and its construction method with high construction efficiency, good economic benefits and simple and stable structure.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned defects and provide a cantilever bridge side span formwork system and its construction method.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

The present invention provides a construction method for a side span formwork system of a cantilever bridge, comprising the following steps:

Step 1. Pre-embedded steel plates are pre-embedded at the top of the pouring side-span buttresses, a support frame with upper, middle and lower support beams is installed on the pre-embedded steel plates, and external temporary supports are installed on the top of the pouring side-span buttresses;

Step 2: Install a temporary fixed pier above the top plate of the poured bridge section, fix the rear upper beam under the top plate of the poured bridge section through the rear sling, anchor the rear lower beam under the bottom plate of the poured bridge section, and the top longitudinal beam The two ends of the pier are respectively connected to the temporary fixed pier and the supporting beam on the upper road of the support frame. Temporary supports and rear slings on the bottom plate, and the bottom longitudinal beams are covered with horizontal distribution beams;

Step 3. Install the front sling in the middle area of the top longitudinal beam and the bracket longitudinal beam, and hang the front beam on the front sling;

Step 4. Install the bottom mold on the horizontal distribution beam, and at the same time lay the bottom mold between the support frame and the permanent support, which is supported by the inner temporary support;

Step 5. Install the outer mold bracket on the longitudinal beam of the bracket, and fix the flange bottom mold and the outer mold on the outer mold bracket by pulling the tie rods;

Step 6: Bind steel bars on the bottom plate of the side span, and install the inner mold on the bottom film.

Further, the inner mold is suspended above the bottom mold through the support angle steel, one end of the support angle steel is arranged on the support beam of the lower channel of the support frame, and the other end is fixed above the bottom plate of the poured bridge section through the anchor rod.

Further, the inner mold includes a support angle steel, a lower inner mold, an inner mold, an upper inner mold, a connecting angle steel and an inner support, and the lower inner mold, the upper inner mold and the two inner molds form a rectangular tube, and the corner is fixed by connecting the angle steel, The supporting angle steel is connected to the lower inner mold, and there are two supporting angle steels, and the supporting angle steel and the connecting angle steel at the edge of the upper inner mold are connected by an inner support.

Two pre-embedded steel plates are arranged at the top of the side span buttresses. The support frame is composed of two supporting longitudinal beams and three upper, middle and lower supporting beams arranged between the supporting longitudinal beams. The bottom of the supporting longitudinal beams is set on the pre-embedded steel plate. There are two supporting frames, and the two supporting frames are connected by reinforcing braces.

Further, the top of the side span buttress is divided into two installation positions by the support frame, and each installation position is provided with an inner temporary support, a permanent support and an outer temporary support in sequence from the support frame to the edge of the top surface of the side span support pier. stand.

Further, the bottom mold and the top of the permanent support are of equal height.

Further, the front cross member and the rear lower cross member are at the same level.

Further, an end form is installed on the side of the support frame.

The cantilever bridge side span formwork system is built through the above steps.

The present invention has the following beneficial effects:

The side span closed section construction is carried out without a hanging basket, and the top support frame of the side span pier and the poured bridge section are used as the gravity support structure for the construction of the side span closed section of the cantilever bridge, which reduces the hoisting workload, thereby reducing the construction period and cost.

The support frame is formed by welding between the support longitudinal beam and the support cross beam, which has a simple structure and facilitates the simultaneous construction of the cast-in-place beams of the side spans on both sides of the side span buttresses, which reduces the construction period. The stability of the support structure.

There is no need for an inner support frame when the inner mold is installed, the structure is stable and simple, the installation is convenient, the consumption of steel is reduced, and the construction is efficient and fast.

Of course, it is not necessary for any product embodying the present invention to achieve all of the above-described advantages simultaneously.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Figure 1 is a schematic diagram of the side span formwork system of a cantilever bridge;

Fig. 2 is the schematic diagram of pier top support frame;

Figure 3 is a schematic diagram of the pier top support system for side span buttresses;

Figure 4 is a schematic view of a formwork carrier system;

Fig. 5 is the schematic diagram of bottom mold arrangement;

Fig. 6 is the schematic diagram of flange bottom mould and outboard mould arrangement;

Figure 7 is a schematic cross-sectional view of the inner mold;

Figure 8 is a schematic cross-sectional view of the side span formwork system of a cantilever bridge;

In the accompanying drawings, the list of components represented by each number is as follows:

1- Reinforcing support; 2- Support beam; 3- End form; 4- Support longitudinal beam; 5- Pre-embedded steel plate; 6- Inner temporary support; 7- Permanent support; 8- Outer temporary support; 9- Top Longitudinal beam; 10-bottom formwork; 11-bottom longitudinal beam; 12-transverse distribution beam; 13-front sling; 14-support angle steel; 15-support longitudinal beam; 16-lower inner formwork; 17-front beam; 18-temporary Fixed pier; 19-rear upper beam; 20-anchor rod; 21-rear sling; 22-rear lower beam; 23-side span buttress; 24-inner mold; 25-outer mold bracket; 26-inner mold; Upper inner mold; 28-connecting angle steel; 29-inner support; 30-cast bridge section; 31-flange bottom mold; 32-outside mold.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around", etc. Indicates the orientation or positional relationship, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, are constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention .

The technical requirements for welding between steel bars, the key points of concrete pouring, the compaction of plain soil, and the construction quality standards of pile foundations, etc., are not repeated in the present invention, and the embodiments of the structure of the present invention are focused on.

Please refer to Figures 1-8, the present invention is a cantilever bridge side span formwork system:

Two pre-embedded steel plates 5 are arranged on the top of the side span buttresses 23 , and support longitudinal beams 4 are welded on the two pre-embedded steel plates 5 . The three supporting beams 2 are connected together, and the supporting frame is formed by the supporting longitudinal beam 4 and the supporting beam 2, and then the formed supporting frames are connected together by the reinforcing brace 1, and the top of the side span support pier 23 is divided into Two parts, each part is provided with an inner temporary support 6, a permanent support 7, and an outer temporary support 8 in sequence from the support frame to the edge of the side span buttress 23.

The end of the poured bridge section 30 has a top plate and a bottom plate, wherein the rear upper beam 19 is fixed under the top plate by the rear strap 21, and the rear lower beam 22 is fixed under the bottom plate by the rear strap 21, wherein the rear lower beam 22 and A bottom longitudinal beam 11 is erected on the outer temporary support 8, wherein the bottom longitudinal beam 11 is provided with a row, and a bracket longitudinal beam 15 is erected between a supporting beam 2 in the middle of the support frame and the rear upper beam 19, and the other is on the top plate. The surface is also provided with a temporarily fixed pier 18. The temporary fixed pier 18 and the support beam 2 at the top of the support frame are provided with a top longitudinal beam 9. The corresponding top longitudinal beam 9 and the middle area of the support longitudinal beam 15 are installed with front slings 13. A front beam 17 is fixed on the sling 13, wherein the front beam 17 and the rear lower beam 22 are at the same level, and a row of transverse distribution beams 12 is erected on the bottom longitudinal beam 11, and the bottom mold 10 is laid on the transverse distribution beam 12. A bottom mold 10 is also laid between the support frame and the permanent support 7, and this part of the bottom mold 10 is supported by the inner temporary support 6, the support longitudinal beam 15 is framed with an outer mold support 25, and the outer mold support 25 is installed with flanges The bottom mold 31 and the outer mold 32, the specific outer mold support 25 has a stepped cross-section, an outer mold is installed on its outer surface, and a flange bottom mold 31 is provided on the stepped surface. Specifically, the tension rod is tightened and fixed. The bracket longitudinal beam 15 abuts against the lower surface of the flange bottom mold 31 .

The inner mold 24 is suspended above the bottom mold 10 through the supporting angle steel 14, one end of the supporting angle steel 14 is arranged on the lowermost supporting beam 2 of the support frame, and the other end is fixed on the bottom plate of the poured bridge section 30 through the anchor rod 20. An end die 3 is installed on the side of the .

The inner mold 24 includes a supporting angle steel 14, a lower inner mold 16, an inner mold 26, an upper inner mold 27, a connecting angle steel 28 and an inner support 29, which are integrally welded and formed.

The lower inner mold 16 , the upper inner mold 27 and the two inner molds 26 form a rectangular tube, the corners of which are fixed by connecting angle steels 28 .

The supporting angle steel 14 is connected to the lower inner mold 16 , and two supporting angle steels 14 are provided and are respectively connected with the two connecting angle steels 28 at the two edges of the upper inner mold 27 through inner supports 29 .

Construction method of side span formwork system of cantilever bridge:

Step 1. Pre-embedding the pre-embedded steel plate 5 at the top of the pouring side span buttresses 23, and installing the support frame with the upper, middle and lower supporting beams 2 on the pre-embedded steel plate 5, wherein the two supporting longitudinal beams 4 and The upper, middle and lower support beams 2 arranged between the support longitudinal beams 4 are pre-assembled, and then hoisted to the top surface of the side span buttresses 23 to be installed on the embedded steel plate 5. 1. Connect and reinforce the two support frames. After the subsequent construction process is completed, install the end form 3 on one side of the support frame;

Among them, the outer temporary support 8 is installed on the top of the pouring side span support pier 23, and the top of the side span support 23 at the inner side of the outer temporary support 8 is also provided with a permanent support 7 and an inner temporary support 6 in sequence.

Step 2: Install the temporary fixed pier 18 above the top plate of the poured bridge section 30, fix the rear upper cross beam 19 under the top plate of the poured bridge section 30 through the rear sling 21, and anchor the rear lower cross beam 22 on the poured bridge section 30. Below the bottom plate, the bottom longitudinal beam 11, the bracket longitudinal beam 15 and the upper longitudinal beam 9 are erected;

Specifically, the two ends of the top longitudinal beam 9 are respectively connected to the temporary fixed pier 18 and the supporting beam 2 on the upper road of the support frame, and the two ends of the supporting longitudinal beam 15 are respectively connected to the supporting beam 2 of the middle road of the supporting frame and the suspenders 21 provided on the top plate. , the two ends of the bottom longitudinal beam 11 are respectively connected to the outer temporary support 8 and the rear strap 21 provided on the bottom plate, and the bottom longitudinal beam 11 is covered with horizontal distribution beams 12 .

Step 3: Install the front sling 13 in the middle area of the top longitudinal beam 9 and the support longitudinal beam 15 , and hang the front cross beam 17 on the front sling 13 .

Step 4: Install the bottom mold 10 on the lateral distribution beam 12, and at the same time lay the bottom mold 10 between the support frame and the permanent support 7, and support 6 by the inner temporary support.

Step 5: Install the outer mold support 25 on the support longitudinal beam 15 , and fix the flange bottom mold 31 and the outer mold 32 on the outer mold support 25 by pulling and pulling rods.

Step 6: Bind the steel bars on the bottom plate of the side span, and install the inner mold 24 on the bottom film 10, wherein the inner mold 24 is prefabricated or made on site on the bottom film 10. It is suspended above the bottom mold 10 , one end of the supporting angle steel 14 is set on the lowermost supporting beam 2 of the support frame, and the other end is fixed above the bottom plate of the poured bridge section 30 through the anchor rod 20 .

In the description of this specification, description with reference to the terms "one embodiment," "example," "specific example," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the present invention. in one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-disclosed preferred embodiments of the present invention are provided only to help illustrate the present invention. The preferred embodiments do not exhaust all the details, nor do they limit the invention to only the described embodiments. Obviously, many modifications and variations are possible in light of the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (9)

1. The construction method of the cantilever bridge side span formwork system is characterized by comprising the following steps:

firstly, pre-burying a steel plate (5) at the top of a pouring side span buttress (23), mounting a support frame with an upper support beam, a middle support beam and a lower support beam (2) on the pre-buried steel plate (5), and mounting and arranging an outer temporary support (8) at the top of the pouring side span buttress (23);

step two, installing a temporary fixing pier (18) above a top plate of a poured bridge section (30), fixing a rear upper cross beam (19) below the top plate of the poured bridge section (30) through a rear hanging strip (21), anchoring a rear lower cross beam (22) below a bottom plate of the poured bridge section (30), respectively connecting two ends of a top longitudinal beam (9) to the temporary fixing pier (18) and a supporting cross beam (2) of an upper way of a supporting frame, respectively connecting two ends of a support longitudinal beam (15) to the supporting cross beam (2) of a middle way of the supporting frame and the hanging strip (21) arranged on the top plate, respectively connecting two ends of a bottom longitudinal beam (11) to an outer temporary support (8) and the rear hanging strip (21) arranged on the bottom plate, and fully paving a transverse distribution beam (12) on the bottom longitudinal beam (11);

thirdly, mounting a front hanging strip (13) in the middle area of the top longitudinal beam (9) and the support longitudinal beam (15), and hanging a front cross beam (17) on the front hanging strip (13);

fourthly, mounting a bottom die (10) on the transverse distribution beam (12), laying the bottom die (10) between the support frame and the permanent support (7), and supporting the bottom die (10) by the inner temporary support (6);

fifthly, an outer mold support (25) is installed on the support longitudinal beam (15), and the flange bottom die (31) and the outer mold (32) are fixed on the outer mold support (25) through a counter-pulling pull rod;

and sixthly, binding steel bars on the bottom plate of the side span section, and installing the inner mold (24) on the bottom film (10).

2. The cantilever bridge side span formwork system construction method according to claim 1, wherein the inner formwork (24) is suspended above the bottom formwork (10) through a support angle steel (14), one end of the support angle steel (14) is arranged on a support cross beam (2) of a lower course of the support frame, and the other end is fixed above a bottom plate of a poured bridge section (30) through an anchoring rod (20).

3. The cantilever bridge side span formwork system construction method according to claim 2, wherein the inner mold (24) comprises support angle steel (14), a lower inner mold (16), inner side molds (26), an upper inner mold (27), connecting angle steel (28) and inner supports (29), the lower inner mold (16), the upper inner mold (27) and the two inner side molds (26) form a rectangular cylinder, the corners of the rectangular cylinder are fixed through the connecting angle steel (28), the support angle steel (14) is connected to the lower inner mold (16), two support angle steel (14) are arranged, and the support angle steel (14) and the connecting angle steel (28) at the edges of the upper inner mold (27) are connected through the inner supports (29).

4. The cantilever bridge side span formwork system construction method according to claim 1, wherein two embedded steel plates (5) are arranged at the top of the side span buttress (23), the support frame is composed of two support longitudinal beams (4) and three upper, middle and lower support cross beams (2) arranged between the support longitudinal beams (4), the bottom of each support longitudinal beam (4) is arranged on the embedded steel plates (5), two support frames are arranged, and the two support frames are connected through the reinforcing support (1).

5. The cantilever bridge side span formwork system construction method according to claim 1, wherein the top of the side span buttress (23) is divided into two installation positions by a support frame, and an inner temporary support (6), a permanent support (7) and an outer temporary support (8) are sequentially arranged from the support frame to the edge of the top surface of the side span buttress (23) on each installation position.

6. The cantilever bridge side-span formwork system construction method according to claim 1, wherein the top of the bottom formwork (10) and the top of the permanent support (7) are equal in height.

7. The cantilever bridge side-span formwork system construction method according to claim 1, wherein the front cross beam (17) and the rear lower cross beam (22) are at the same level.

8. The cantilever bridge side-span formwork system construction method according to claim 1, characterized in that an end formwork (3) is installed on the side surface of the supporting frame.

9. A cantilever bridge side span formwork system is characterized by being built through the steps.

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