CN105803946B - Quickly adjustable support for a cover beam and its construction method - Google Patents

Abstract

The invention discloses a quickly adjustable support for a cover beam and a construction method thereof. The construction method includes the following steps: (1) installation of a hoop; (2) installation of a mechanical jack; (3) installation of a beam; (4) installation of a longitudinal beam (5) Bottom formwork installation; (6) Steel bar binding; (7) Side formwork installation; (8) Concrete pouring; (9) Formwork support removal. The invention has the advantage that the mechanical jack can freely adjust the height of the bottom formwork of the support to the design position, and the mechanical jack will not retract and slide down. Compared with the traditional wedge-shaped block, it is more convenient and quick to remove the support, shortening the duration of the process and improving the cover. The stability and safety of the beam support.

Description

Quickly adjustable support for a cover beam and its construction method

technical field

The invention belongs to the technical field of construction of a cylindrical pier column cover beam of a bridge substructure, and in particular relates to a quickly adjustable support for a cover beam and a construction method thereof.

Background technique

With the development of construction projects, the cylindrical pier-column-cap-beam structure has been widely used in bridge construction in our country. According to the current support forms of cover beams, there are methods such as piercing rod method, steel pipe support method, and bowl buckle support method.

Contents of the invention

In order to solve the deficiencies in the prior art, the present invention provides a rapidly adjustable support for the cover beam and its construction method, which can adjust the elevation of the bottom mold of the support to the design position within a certain range, and has strong flexibility, high speed The advantages of quick and convenient, it is easier to ensure the accuracy of the elevation of the cover beam structure, while reducing the labor intensity, simplifying the construction process, improving work efficiency, speeding up the construction progress, ensuring the physical quality of the structure, and can be compared with traditional construction Safer bracket removal.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme: a construction method for the quickly adjustable support of the cover beam, which is carried out in turn according to the following steps:

(1) Hoop installation: Calculate the hoop installation height of the circular pier column according to the height of the cover beam, and install the hoop designed by force calculation on the specified elevation after measuring with the level gauge;

(2) Mechanical jack installation: install the mechanical jack on the hoop corbel;

(3) Beam installation: install the beam on the top of the mechanical jack;

(4) Longitudinal beam installation: install the longitudinal beam on the beam;

(5) Bottom form installation: install the bottom formwork of the cover beam on the longitudinal beam, and set up triangular brackets on the bottom formwork at both ends of the longitudinal beam. The elevation is accurately installed to the design elevation;

(6) Reinforcement binding and installation: The pre-bound cover beam reinforcement cage is transported to the construction site, and the cover beam reinforcement cage is hoisted and installed to the designed position on the bottom formwork;

(7) Side form installation: side form and end form are installed in place according to the design size, and tie bars are installed;

(8) Concrete pouring: Concrete pouring shall be carried out according to the specifications and design requirements;

(9) Formwork support removal: When the concrete strength reaches 2.5MPa, remove the side formwork and end formwork. When the strength reaches 85% of the design strength, start to remove the triangular support, adjust the mechanical jack, remove the longitudinal beam and beam, remove the mechanical jack, and remove the hoop.

In the step (1), a white geotextile is installed between the hoop and the pier.

In the step (2), three limit steel bars are welded and processed on the hoop bracket, so that the bottom of the mechanical jack is just installed inside.

Multiple tie rods are arranged between the beams in the step (3).

In the step (5), after the bottom mold is installed, the triangle bracket is preloaded with steel bars, and the force calculation is verified on the spot to check whether the triangle bracket is deformed.

In the step (8), after the concrete is poured, the cover beam is watered and cured, and the time of watering and curing is not less than 7 days.

The process of the mechanical jacks in the step (9) includes the following process: Synchronously adjust the two mechanical jacks on the same hoop downwards, adjust 2cm for the first time, then adjust the two mechanical jacks at the other end down 4cm, and gradually Adjust down about 7cm.

A quick-adjustable bracket for a cover beam of the present invention comprises a hoop arranged on a circular pier column, the hoop brackets on both sides of the hoop are respectively provided with vertical mechanical jacks, and the top of each mechanical jack is A crossbeam is provided, and a plurality of longitudinal beams are installed on the crossbeam, and the plurality of longitudinal beams are arranged at intervals along the length direction of the crossbeam, and each longitudinal beam is horizontally erected between two crossbeams, and a bottom formwork is installed on the longitudinal beam, and the bottom formwork The top pouring is provided with a cover beam.

A triangular bracket is arranged between the bottom formwork at both ends of the longitudinal beam and the longitudinal beam.

There are multiple pull rods arranged between the two beams.

The beneficial effects of the present invention are:

The invention is applicable to various cylindrical pier-column-cover-beam structures, with I-beams and hoops as the supporting force, and a mechanical jack as the unloading adjustment device for the bottom bracket, which can adjust the elevation of the bottom mold of the bracket to within a certain range The design position is flexible, fast and convenient, and it is easier to ensure the accuracy of the elevation of the cover beam structure. At the same time, it can reduce the labor intensity, simplify the construction process, improve work efficiency, speed up the construction progress, and ensure the physical quality of the structure. . When the bracket is removed, the mechanical jack is easy to remove, and the bracket can be removed more safely than traditional construction. The mechanical jack of the present invention can freely adjust the height of the bottom formwork of the bracket to the design position, and the mechanical jack will not retract and slide down. Compared with the traditional wedge-shaped block, it is more convenient and quick to remove the bracket, shortening the duration of the process and improving the cover beam bracket. stability and security.

Description of drawings

Fig. 1 is the sectional view of the quickly adjustable support of the cover beam of the present invention;

Fig. 2 is a cross-sectional view of the quickly adjustable support for the cover beam of the present invention.

detailed description

As shown in Fig. 1 to Fig. 2, a kind of cover beam of the present invention can quickly adjust the construction method of support, and this construction method is carried out according to the following steps successively:

(1) Hoop installation: The hoop installation is to calculate the hoop installation elevation on the circular pier 6 according to the height of the cover beam, and install the hoop 5 designed by force calculation on the specified elevation after measuring with the level instrument. A white geotextile is installed between the hoop 5 and the pier column 6 to enhance the friction between the hoop 5 and the pier column 6 and to protect the appearance of the pier column. The hoop connection bolts are high-strength bolts, and the torque wrench is used to verify the tightening of the bolts. After the bolts have been used for a period of time, check the condition of the bolt wires in time, and replace the bolts in time if they are found to be detached or damaged.

(2) Mechanical jack installation: The mechanical jack 4 is installed on the hoop corbel, a total of four, and three 1cm high limit steel bars are welded and processed on the hoop corbel, so that the bottom of the mechanical jack 4 is just installed inside to prevent Mechanical jack 4 moves the action.

(3) Installation of beams: install I45c I-beam beams 3 on the top of mechanical jack 4, in order to prevent beams 3 from tilting, and set 5 steel tie rods between beams 3. The elevation adjustment of the top surface of the mechanical jack 4 on both sides of the same pier column is consistent.

(4) Longitudinal beam installation: install I16 I-shaped steel longitudinal beam 2 on I45c I-shaped steel beam 6, and the distance between longitudinal beams 2 is 50cm.

(5) Bottom form installation: Install the bottom formwork 1 of the cover beam on the I16 I-beam longitudinal beam 2 (bottom formwork 1 at both ends has a triangular bracket 7). After the bottom formwork 1 is installed, polish and paint the formwork paint. And the bottom template elevation is remeasured, if the bottom template has an error generally within 3cm, the bottom template elevation can be accurately installed to the design elevation by adjusting the mechanical jack 4 up and down. When the bracket is used for the first time, after the bottom mold is installed, sand bags are used to pre-press the bracket, and the force calculation is verified on the spot to check whether the bracket is deformed.

(6) Binding and installation of steel bars: The steel bars are processed in the processing shed and bound on the pedestal. The intersections of the steel bars are bound firmly with iron wires, and the joints of the main bars are double-sided lap welded. The cover beam reinforcement cages processed and bundled in the steel bar processing plant are transported to the construction site by gun trucks, hoisted by a 25T crane and installed to the design position on the bottom formwork, and bound on the lower side support pads of the bottom steel bars with the same label as the cover beam concrete The concrete pads are arranged in a quincunx-shaped staggered pattern and soaked with water before binding to ensure that the protective layer of steel bars meets the design requirements.

(7) Side formwork installation: side formwork installation is to carry out side formwork construction after the steel bars of the cover beam have been bound and passed the inspection. The side mold is made of shaped steel mold designed and manufactured by a professional formwork factory. It must be polished and derusted before installation, and the mold release agent should be evenly applied after polishing. The steel formwork is spliced on site, and the cover beam is lifted manually by a crane for installation, and the formwork is established according to the longitudinal and transverse axes of the cover beam and the design geometric dimensions. The joints between side molds and side molds, and between side molds and bottom molds should be tight. The connecting bolts between the templates are designed to be M22, fixed with double nuts, and double-sided adhesive strips are padded to prevent grout leakage. The side form reinforcement is made of 18mm rebar with a length of 2.8m. The tie rods are arranged in double rows, the position of the bottom row of tie rods passes under the bottom formwork, and the upper layer of tie rods is arranged on the top surface of the formwork. The horizontal distance between the tie rods is 80cm. The misalignment is within 2mm to ensure the smoothness of the poured concrete. Before the installation of the side formwork, bind the concrete pads on the outer sides of the reinforcement layer on both sides of the cover beam, and the concrete pads are arranged in a quincunx-shaped staggered manner with a spacing of 50cm to 70cm. Ensure the thickness of the pouring protective layer. The installation of the side form and the end form is the conventional technical ability of those skilled in the art.

(8) Concrete pouring: Before concrete pouring, carefully check the reinforcement size and firmness of the formwork, and concrete pouring can only be carried out after passing the test. Concrete is transported by tank truck, and poured with a crane and a large hopper so that the concrete can be directly poured into the mold. The free fall height of pouring shall not exceed 2m. Before pouring, the concrete transport vehicle shall be forced to stir for 2 minutes, and the formwork and column head shall be sprinkled with water to moisten them. When pouring, the concrete should be poured horizontally in layers and obliquely in sections. The concrete cloth should be poured from one end of the cover beam to the other end. It should be vibrated while pouring, and the layered thickness of the poured concrete should be about 30 cm, so as to prevent large oblique overlapping surfaces. The concrete is vibrated using a plug-in vibrator with a diameter of 50mm, and the moving distance shall not exceed 1.5 times the radius of action of the vibrator; a distance of 5-10cm should be kept from the side form; 5-10cm should be inserted into the lower concrete; Xu Xu raised the vibrating rod; it should be avoided that the vibrating rod collides with the formwork, steel bars and other embedded parts, causing the deformation of the formwork and the displacement of the embedded parts. When the concrete surface stops sinking, bubbles no longer appear, and the surface is flat and muddy, it indicates that the concrete has been vibrated and compacted. Concrete pouring is a routine technical ability of those skilled in the art.

During the pouring of concrete, a special person shall be appointed to check the stability of supports, formwork, steel bars and embedded parts. When any looseness, deformation or displacement is found, it shall be dealt with in time.

After the concrete pouring is completed, the concrete surface should be trimmed and smoothed in time, and the surface should be plastered a second time after 0.5 hours. When the concrete strength reaches 2.5mPa, use a special awl to chisel the range of the support pad stone to expose the large grain stones in the concrete, so as to ensure that the support pad stone and the cover beam concrete are well connected.

Concrete maintenance adopts geotextile covering and curing. After the concrete pouring is completed and the initial setting is completed, the geotextile is covered to moisturize and maintain. The curing time is not less than 7 days. Four plastic buckets with holes in the bottom are placed above the cover beam, and the water is pumped up by a water pump, and a special person is arranged to pump water for moisturizing and curing to ensure that the concrete will not lose water and dry out. When the temperature is lower than 5°C, it is forbidden to water the concrete for curing.

(9) Removal of formwork support: Remove the side formwork and end formwork when the concrete strength reaches 2.5MPa. After 7 days of concrete curing, perform strength testing on the concrete test block. When the strength reaches 85% of the design strength, start to remove the support formwork. Adjust the two mechanical jacks 4 on the hoop downwards, adjust 2cm for the first time, then adjust the two mechanical jacks at the other end down 4cm, gradually lower the two ends by about 7cm, start to remove the longitudinal beam 2 and crossbeam 3, remove the mechanical jack 4, remove Hoop 5.

As shown in Figures 1 to 2, a quick-adjustable bracket for a cover beam of the present invention includes a hoop 5 arranged on a circular pier column 6, and the hoop brackets on both sides of the hoop 5 are respectively provided with vertical The mechanical jack 4 is oriented, and the top of each mechanical jack 4 is provided with an I-beam beam 3, and there are multiple reinforcement rods between the two I-beam beams 3 (the rods are not marked in the accompanying drawings), and the I-beam A plurality of I-steel longitudinal beams 2 are installed on the beam 3, and the plurality of I-steel longitudinal beams 2 are arranged at intervals along the length direction of the I-steel beam 3, and each I-steel longitudinal beam 2 is horizontally erected on two Between the beams 3 of the I-beam, a bottom template 1 is installed on the longitudinal beam 2 of the I-beam, and a triangular bracket 7 is set between the bottom template 1 at both ends of the I-beam 2 and the longitudinal beam 2 of the I-beam, and the bottom template 1 The top pouring is provided with a cover beam 8 .

The invention is applicable to various cylindrical pier-column-cover-beam structures, with I-beams and hoops as the supporting force, and a mechanical jack as the unloading adjustment device for the bottom bracket, which can adjust the elevation of the bottom mold of the bracket to within a certain range The design position is flexible, fast and convenient, and it is easier to ensure the accuracy of the elevation of the cover beam structure. At the same time, it can reduce the labor intensity, simplify the construction process, improve work efficiency, speed up the construction progress, and ensure the physical quality of the structure. . When the bracket is removed, the mechanical jack is easy to remove, and the bracket can be removed more safely than traditional construction. The mechanical jack of the present invention can freely adjust the height of the bottom formwork of the bracket to the design position, and the mechanical jack will not retract and slide down. Compared with the traditional wedge-shaped block, it is more convenient and quick to remove the bracket, shortening the duration of the process and improving the cover beam bracket. stability and security.

The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced without departing from it. Any modifications or partial replacements within the spirit and scope of the present invention shall fall within the scope of the claims of the present invention.

Claims (8)

1. A construction method for fast adjustable support of a cap beam, characterized in that the construction method is carried out in the following steps: (1) Hoop installation: Calculate the hoop installation height of the circular pier column according to the height of the cover beam, and install the hoop designed by force calculation on the specified elevation after measuring with the level gauge; (2) Mechanical jack installation: install the mechanical jack on the hoop corbel; (3) Beam installation: install the beam on the top of the mechanical jack; (4) Longitudinal beam installation: install the longitudinal beam on the beam; (5) Bottom form installation: install the bottom formwork of the cover beam on the longitudinal beam, and set up brackets between the bottom formwork and the longitudinal beam at both ends of the longitudinal beam. The jack makes the height of the bottom formwork accurately installed to the design height; (6) Reinforcement binding and installation: The pre-bound cover beam reinforcement cage is transported to the construction site, and the cover beam reinforcement cage is hoisted and installed to the designed position on the bottom formwork; (7) Side form installation: side form and end form are installed in place according to the design size, and tie bars are installed; (8) Concrete pouring: Concrete pouring shall be carried out according to the specifications and design requirements; (9) Formwork support removal: When the concrete strength reaches 2.5MPa, the side formwork and end formwork are removed. When the strength reaches 85% of the design strength, the triangular support is removed, the mechanical jack is adjusted, the longitudinal beams and beams are removed, the mechanical jack is removed, and the hoop is removed; In the step (2), three limit steel bars are welded and processed on the hoop bracket, so that the bottom of the mechanical jack is just installed inside; The process of the mechanical jacks in the step (9) includes the following process: Synchronously adjust the two mechanical jacks on the same hoop downwards, adjust 2cm for the first time, then adjust the two mechanical jacks at the other end down 4cm, and gradually Adjust down about 7cm. 2. The construction method of the rapidly adjustable support of the cover beam according to claim 1, characterized in that: in the step (1), a white geotextile is installed between the hoop and the pier column. 3. The construction method of the quickly adjustable bracket of the cover beam according to claim 1, characterized in that: multiple tie rods are arranged between the beams in the step (3). 4. The construction method of quickly adjustable brackets for cover beams according to claim 1, characterized in that: after the installation of the bottom mold in the step (5), steel bars are used to preload the brackets, and the force calculation is verified on the spot. Whether the bracket is deformed. 5. The construction method of the quickly adjustable support of the cover beam according to claim 1, characterized in that: in the step (8), after the concrete is poured, the cover beam is watered and cured, and the time for watering and curing is not less than 7 days. 6. A quickly adjustable support for a cover beam that realizes the construction method described in claim 1, characterized in that it includes hoops arranged on circular pier columns, and the hoop brackets on both sides of the hoop are respectively provided with vertical The top of each mechanical jack is equipped with a crossbeam, and multiple longitudinal beams are installed on the crossbeam. The multiple longitudinal beams are arranged at intervals along the length of the crossbeam, and each longitudinal beam is horizontally erected between two crossbeams. In the room, a bottom formwork is installed on the longitudinal beam, and a cover beam is poured on the bottom formwork. 7. The quickly adjustable support for the cover beam according to claim 6, characterized in that: a triangular bracket is arranged between the bottom formwork and the longitudinal beam at both ends of the longitudinal beam. 8. The quickly adjustable support for the cover beam according to claim 6 or 7, characterized in that: multiple pull rods are arranged between the two cross beams.