CN110593115A - Cast-in-place box girder support system and its construction method - Google Patents

Abstract

The invention relates to a cast-in-place box girder support system, including column supports, hoop supports, electro-hydraulic jacks, beams, Bailey beams and bottom formwork beams; the column supports are mainly composed of two steel columns and a foundation, and the steel An electro-hydraulic jack is set on the column, a column tie beam is set between two steel columns, the foundation is set at the tip of the high-level area of the steep terrain; a high pier is set in the low-level area of the steep terrain; the hoop support is mainly composed of through holes, Composed of L-shaped hoop plates, stiffeners and tension bolts, the through holes are reserved in the high pier. in the hole. The beneficial effects of the invention are: the invention utilizes the existing high piers to form a hoop support system, which reduces the process of erecting steel columns near the high piers in the traditional technology, increases the construction speed, and reduces the construction cost.

Description

Cast-in-place box girder support system and its construction method

technical field

The invention relates to a support system, in particular to a cast-in-place box girder support system and a construction method thereof.

Background technique

At present, during the construction of cast-in-place beams, the general construction method is to first reinforce the foundation, and then set up a full support to place the formwork and steel bars and then carry out concrete pouring construction. A commonly used support form in the construction of cast-in-place box girders with high piers is the combined support of Bailey beams and steel pipe columns (that is, Bailey beams + steel pipe columns as supports), especially in the case of heavy loads, high pier columns, and large spans. , which is a more economical and safer bracket type. Related patents include: construction support system of cast-in-place box for high bridge piers (ZL 201520713361.0), a construction method for bridges with few supports, and bridges (ZL201610423219.1), construction of cast-in-place box girders combining hoops and Bailey beams without floor supports Method (under substantive examination, application number CN201810746490.8), Bailey beam cable saddle lifting bracket (ZL 201820129079.1), a simply supported bridge support structure based on Bailey beam bracket (ZL 201620340399.2), Bailey beam at the bottom of a bridge crossing a river A temporary support lifting and floating removal method (ZL 201711227627.0), a Bailey beam support removal device (ZL 201821049367.2). However, for the cast-in-place box girder with high pier with a steep terrain and a pier body height of 40m or more, the use of full-wall support not only has the disadvantages that the steel pipe column and its foundation cannot be erected or erected, and the long-span Bailey beam is too long to cause the middle There are problems such as large deflection of parts and large preloading construction of the support system, and the safety is low, and the investment in materials and personnel is also large. Therefore, in order to overcome these problems, it is urgent to find a cast-in-place box girder support system and its construction method suitable for steep terrain.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide a cast-in-place box girder support system and a construction method thereof.

This cast-in-place box girder support system includes column supports, hoop supports, electro-hydraulic jacks, beams, Bailey beams and bottom formwork beams; the column supports are mainly composed of two steel columns and foundations, and the steel columns An electro-hydraulic jack is set on the top, a column beam is set between two steel columns, the foundation is set at the tip of the high-level area of the steep terrain; a high pier is set in the low-level area of the steep terrain; the hoop support is mainly composed of through holes, L The L-type hoop plate is composed of a stiffening rib and a tension bolt, and the through hole is reserved in the high pier. Middle; the electro-hydraulic jack on the top of the steel column and the electro-hydraulic jack on the top of the hoop support are equipped with beams, the Bailey beam is set above the beam, the bottom form beam is set on the top of the Bailey beam, the support is set on the top of the high pier, and the bottom form beam Set the cast-in-place box girder formwork above the support.

As a preference: if the span of the beam is too large, use a prestressed Bailey beam. The prestressed Bailey beam is provided with end plates at both ends of the Bailey beam. Stress tendons pass through tendon holes and anchors.

As an optimization: the electro-hydraulic jack is provided with a base for bolting, and is bolted to the column support and the hoop support.

As an optimization: the bottom of the beam is provided with a groove, and is docked with the plunger of the electro-hydraulic jack.

As a preference: the top of the bottom form beam is flush with the top of the support on the high pier.

Preferably: the section of the steel column is a rounded rectangle.

The construction method of this cast-in-place box girder support system comprises the following steps:

1) When constructing a high pier, reserve a through hole at a suitable position on the upper part, and then set an L-shaped hoop plate on both sides of the through hole. The L-shaped hoop plate is provided with stiffening ribs and reserved holes for bolts. The through hole and the bolt reserved hole are provided with pull bolts to form a hoop support;

2) In the steep terrain between the two spans of high pier columns, find an area suitable for steel columns and their foundation construction, carry out foundation construction, and then erect two steel pipe columns, and use steel pipe columns to fix the steel columns when installing them. And set the column tie beam between the steel columns;

3) Install electro-hydraulic jacks on the hoop supports and steel columns respectively;

4) Place beams respectively on the hoop support and the electro-hydraulic jack of the steel column, the bottom of the beam is provided with a groove, and docked with the plunger of the electro-hydraulic jack;

5) Hang the Bailey beam on the beam supported by the hoop, and place the support on the top of the high pier at the same time, and hang the Bailey beam on the beam supported by the column at the same time; if the span of the beam is too large, use prestressed Bailey Beams; prestressed Bailey beams are provided with end plates at both ends of Bailey beams, and prestressing is applied through the tendon holes, prestressed tendons and anchors in the lower part of the end plates;

6) On the Bailey beam, set the bottom form beam according to a certain interval, and then gradually lay out the cast-in-place box girder formwork, steel bars and prestressed system on the bottom form beam;

7) Concrete is poured, and the electro-hydraulic jack is started at the same time for automatic height compensation. As more concrete is poured, more compensation will be made. After the concrete is poured and reaches a certain strength, prestress is applied;

8) After the strength of the cast-in-place box girder of the high pier meets the requirements, remove the formwork of the cast-in-place box girder, bottom form beam, Bailey beam, beam, electro-hydraulic jack, hoop support and column support in sequence, and place the The through holes are backfilled with concrete.

The beneficial effects of the present invention are:

(1), the present invention utilizes the existing high pier to form the hoop support system, which reduces the process of erecting steel columns near the high pier in the traditional technology, increases the construction speed, and reduces the engineering cost.

(2), the steel column of the present invention is arranged at the tip of the high position between two adjacent high piers, and two rounded rectangular columns and column tie beams are used to form a steel column, which enhances the lateral rigidity of the column and also The height of the steel column can be reduced, thereby reducing the cost and having obvious economic benefits.

(3) The electrohydraulic jack of the present invention has the function of automatic height compensation, so that the whole support does not need to be preloaded, and has obvious technical and economic benefits.

(4) For large-span Bailey beams, prestressed Bailey beams can be used, which is beneficial to reduce the middle deflection of Bailey beams, and the automatic compensation of electro-hydraulic jacks can further help ensure the accuracy of the formwork position Accuracy, thereby ensuring the construction accuracy of the cast-in-place box girder.

(5), the prestressed Bailey beam of the present invention is that end plates are arranged on both sides of the traditional Bailey beam, and then prestressing is applied through the reinforcement holes, prestressed tendons and anchors at the bottom of the end plate, and the structure is simple , easy to operate on site.

(6) On the basis of the traditional Bailey beam steel tube column composite support, the present invention forms a composite support system by improving the support system of the Bailey beam, which provides a certain reference value for similar engineering construction.

Description of drawings

Fig. 1 is a schematic diagram of hoop support;

Fig. 2 is the elevation view of steel column;

Fig. 3 is a top view of a steel column;

Fig. 4 is a schematic diagram of hoop support installation jack;

Fig. 5 is a schematic diagram of a jack installed on the top surface of a steel column;

Figure 6 is a detailed view of the bottom of the beam;

Fig. 7 is a schematic diagram of setting a crossbeam on the hoop support;

Fig. 8 is a schematic diagram of crossbeams arranged on steel columns;

Fig. 9 is a schematic diagram of hoisting a Bailey beam on a hoop support and installing a support on a high pier;

Fig. 10 is a schematic diagram of hanging a Bailey beam on a steel column;

Figure 11 is a schematic diagram of a prestressed Bailey beam;

Figure 12 is a schematic diagram of the installation of the formwork system;

Explanation of reference signs: 1-electro-hydraulic jack; 2-beam; 3-Berry beam; 4-bottom form beam; 5-steel column; 6-foundation; 7-column tie beam; 8-steep terrain; 9-through Hole; 10-L-type hoop plate; 11-stiffener; 12-pull bolt; 13-high pier; 14-end plate; 15-reinforcement hole; 16-prestressed tendon; 17-anchor; 18-base ; 19-groove; 20-support; 21-plunger; 22-cast-in-place box girder template.

Detailed ways

The present invention will be further described below in conjunction with the examples. The description of the following examples is provided only to aid the understanding of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

As shown in Figure 1, during the construction of a columnar high pier 13, two rows of through holes 9 are reserved at suitable positions on the upper part, and then an L-shaped hoop plate 10 is arranged on both sides of the through hole 9. The hoop plate 10 is provided with a stiffener 11 and two bolt reserved holes, through two rows of through holes 9 and the two bolt reserved holes, two pull bolts 12 are set to form a hoop support.

As shown in Figures 2 and 3, in the steep terrain 8 between the two spans of the high pier 13 pier columns, find the tip area of the high-position area that is conducive to reducing the length of the steel column 5, and then save the cost, as the steel column 5 and In the area where the foundation 6 is constructed, the foundation 6 is constructed, and then two steel pipe columns are erected on the foundation 6. When installing the steel column 5, the steel column is used to fix it. The top of the steel column 5 must be connected with 13 L-shaped hoops on the high pier The top of the plate 10 is kept flat. After the steel columns 5 are laid and formed, the steel tube columns are removed, and a column tie beam 7 is set between the two steel columns 5. The section of the steel columns 5 is a rounded rectangle.

As shown in Figures 4 and 5, the base 18 for bolting the bottom of the electro-hydraulic jack 1 is bolted to the hoop support and the steel column 5 respectively, and the electro-hydraulic jack 1 has an automatic compensation effect.

As shown in Figures 6, 7, and 8, a columnar beam 2 is respectively placed on each hoop support and steel column 5, and the bottom of the beam 2 is provided with four circular grooves 19, which are connected with the electrohydraulic jack 1 The plunger 21 is docked, and the diameter of the groove 19 is 2 to 3 mm larger than the outer diameter of the plunger 21.

As shown in Figures 9 and 10, the Bailey beam 3 is suspended on the beam 2 supported by the hoop, and the support 20 is placed on the top of the high pier 13 at the same time, and the Bailey beam 3 is also suspended on the beam 2 supported by the column; if If the span of the crossbeam 2 is too large, a prestressed Bailey beam can be used to reduce the deflection of the Bailey beam 3 .

As shown in Figure 11, the prestressed Bailey beam is that end plates 14 are arranged at the two ends of the Bailey beam 3, and the end plates 14 are truss-shaped, and the rib holes 15, prestressed tendons 16 and The anchor 17 is prestressed.

As shown in Figure 12, base form beams 4 are arranged at certain intervals on the Bailey beams 3, and the tops of the base form beams 4 are kept flush with the tops of the supports 20 on the high pier 13 to form a formwork system; On the beam 4, the cast-in-place box girder formwork 22, steel bars and prestressing system are gradually laid out.

Concrete is poured, and the electro-hydraulic jack 1 is started at the same time for automatic height compensation. As more concrete is poured, more compensation will be made. After the concrete is poured and reaches a certain strength, prestress is applied.

After the strength of the cast-in-place box girder of the high pier meets the requirements, the cast-in-place box girder template 22, bottom form beam 4, Bailey beam 3, beam 2, electro-hydraulic jack 1, hoop support and column support are removed in sequence, and the high The through hole 9 on the pier 13 is backfilled.

Claims (7)

1. Cast-in-place box girder support system, its characterized in that: comprises an upright post support, a hoop support, an electric hydraulic jack (1), a cross beam (2), a Bailey beam (3) and a bottom mould beam (4); the upright post support mainly comprises two steel upright posts (5) and a foundation (6), wherein the steel upright posts (5) are provided with electric hydraulic jacks (1), an upright post tie beam (7) is arranged between the two steel upright posts (5), and the foundation (6) is arranged at the tip of a high-level area of a steep terrain (8); a high pier (13) is arranged in a low-level area of the steep terrain (8); the hoop support mainly comprises a through hole (9), an L-shaped hoop plate (10), a stiffening rib (11) and a split bolt (12), the through hole (9) is reserved in a high pier (13), the L-shaped hoop plate (10) is provided with a bolt reserved hole and the stiffening rib (11), and the split bolt (12) is arranged in the through hole (9) and the bolt reserved hole; all be equipped with crossbeam (2) on electro-hydraulic jack (1) at steel stand (5) top and the staple bolt support electro-hydraulic jack (1) at top, crossbeam (2) top sets up bailey roof beam (3), and bailey roof beam (3) top sets up end mould roof beam (4), and high mound (13) top sets up support (20), and end mould roof beam (4) and support (20) top set up cast-in-place case beam mold board (22).

2. The cast-in-place box beam support system of claim 1, wherein: if the span of the cross beam (2) is too large, a prestressed Bailey beam is adopted, end plates (14) are arranged at two ends of the Bailey beam (3), rib holes (15), prestressed ribs (16) and an anchorage device (17) are arranged at the lower parts of the end plates (14), and the prestressed ribs (16) penetrate through the rib holes (15) and the anchorage device (17).

3. The cast-in-place box beam support system of claim 1, wherein: the electro-hydraulic jack (1) is provided with a base (18) for bolting and is bolted on the upright post support and the hoop support.

4. The cast-in-place box beam support system of claim 1, wherein: the bottom of the cross beam (2) is provided with a groove (19) and is butted with a plunger (21) of the electric hydraulic jack (1).

5. The cast-in-place box beam support system of claim 1, wherein: the top of the bottom mould beam (4) is flush with the top of the support (20) on the high pier (13).

6. The cast-in-place box beam support system of claim 1, wherein: the section of the steel upright post (5) is a round corner rectangle.

7. A construction method of a cast-in-place box girder support system based on the steel plate frame as claimed in claim 1 is characterized in that: the method comprises the following steps:

1) when the high pier (13) is constructed, a through hole (9) is reserved at a proper position at the upper part of the high pier, then L-shaped hoop plates (10) are arranged on two sides of the through hole (9), stiffening ribs (11) and bolt reserved holes are arranged in the L-shaped hoop plates (10), and split bolts (12) are arranged through the through hole (9) and the bolt reserved holes to form a hoop support;

2) in a steep terrain (8) between two spans of a pier column of a high pier (13), searching an area suitable for construction of a steel upright column (5) and a foundation (6) thereof, constructing the foundation (6), erecting two steel pipe columns, fixing the steel upright columns (5) by using the steel pipe columns, and arranging upright column tie beams (7) between the steel upright columns (5);

3) the hoop supports and the steel upright posts (5) are respectively provided with an electric hydraulic jack (1);

4) respectively placing a cross beam (2) on the hoop support and the electric hydraulic jack (1) of the steel upright post (5), wherein the bottom of the cross beam (2) is provided with a groove (19) and is butted with a plunger (21) of the electric hydraulic jack (1);

5) the Bailey beam (3) is hung on the cross beam (2) supported by the hoop, the support (20) is placed at the top of the high pier (13), and the Bailey beam (3) is also hung on the cross beam (2) supported by the upright post; if the span of the cross beam (2) is too large, a prestressed Bailey beam is adopted; the prestressed Bailey beam is characterized in that end plates (14) are arranged at two ends of a Bailey beam (3), and prestress is applied through reinforcement holes (15) at the lower part of the end plates (14), prestressed reinforcements (16) and an anchorage device (17);

6) arranging bottom mould beams (4) on the Bailey beam (3) according to a certain interval, and then gradually arranging a cast-in-situ box beam template (22), a reinforcing steel bar and a prestress system on the bottom mould beams (4);

7) the method comprises the following steps of pouring concrete, starting the electric hydraulic jack (1) to perform automatic height compensation, and applying prestress after the concrete is poured and reaches a certain strength, wherein the compensation is increased along with the increase of the poured concrete;

8) and after the strength of the high-pier cast-in-place box girder meets the requirement, sequentially removing the cast-in-place box girder template (22), the bottom formwork girder (4), the Bailey girder (3), the cross beam (2), the electric hydraulic jack (1), the hoop support and the upright post support, and backfilling the through holes (9) in the high piers (13) with concrete.