CN104695336A - Double-layer cast-in-situ beam support construction method adopting sequence from upper layer to lower layer - Google Patents

Abstract

The invention discloses a double-layer cast-in-situ beam support construction method adopting the sequence from the upper layer to the lower layer. In combination of comprehensive consideration of construction of upper-layer cast-in-situ beams and lower-layer cast-in-situ beams, the method that construction of two layers of cast-in-situ beams is met through one support is designed, that is, the upper-layer cast-in-situ beams and the lower-layer cast-in-situ beams share one support. After construction of the upper-layer cast-in-situ beams is finished, upper-layer support steel tubes are dismounted, bailey beams are lowered integrally to a lower-layer cast-in-situ beam support, an upper-layer cast-in-situ beam support is converted into the lower-layer cast-in-situ beam support directly, the high-altitude construction difficulty of the support is reduced, meanwhile, the use time of large hoisting equipment is shortened, the construction process is accelerated, and damage of the lower-layer cast-in-situ beam body due to construction of the upper-layer cast-in-situ beams is avoided.

Description

Construction method of double-layer cast-in-place beam first up and then down

technical field

The invention relates to a construction method of a bridge engineering foundation, in particular to a construction method for a cast-in-place beam support in which the upper-layer cast-in-place beam is constructed first and then the lower-layer cast-in-place beam is constructed according to the structural form that the upper layer is wider than the lower layer.

Background technique

With the increasing investment in infrastructure construction in our country, bridge construction is developing rapidly. In order to reduce construction costs and construction land, many cross-river and river-crossing bridges in China adopt a double-layer structure, and the upper cast-in-place girder is wider than the lower cast-in-place girder. form.

The traditional double-layer cast-in-place beam support construction method generally adopts the construction of the lower floor cast-in-place beam first, and then erects the support according to the width of the upper floor cast-in-place beam. This method has the following disadvantages: 1. When the upper floor cast-in-place beam is wider than the lower floor cast-in-place beam The support of the cast-in-place beam on the upper floor will be affected by the cast-in-place beam on the lower floor. Part of the cast-in-place beam support on the upper floor needs to be supported on the top surface of the cast-in-place beam on the lower floor, and the other part needs to be supported outside the scope of the cast-in-place beam on the lower floor. When the steel pipe support is erected on the ground, there is often a large difference between the height of the support on the lower cast-in-place beam and the height and length of the support supporting the ground (generally, the difference is tens of meters), resulting in mismatching of support stiffness, foundation settlement and inconsistent beam deformation. 2. It is necessary to separately increase the layout of some upper cast-in-place beam support foundations and supports, and the investment is relatively large. 3. The installation and dismantling of the bracket is cumbersome, the construction period is long, and the construction cost of the whole bracket is relatively high. 4. The construction of the upper cast-in-place beams is easy to cause damage to the lower cast-in-place beams.

Contents of the invention

The purpose of the present invention is to provide a set of supports shared by the upper cast-in-place beam and the lower cast-in-place beam, which reduces the difficulty of high-altitude construction of the support, and at the same time reduces the use time of large lifting equipment, speeds up the construction progress, and avoids the construction of the upper cast-in-place beam. Damage to the cast-in-place beam body of the lower layer The construction method of the double-layer cast-in-place beam first up and then down.

The purpose of the present invention is achieved like this:

A double-layer cast-in-place beam first up and then down support construction method, characterized by:

A. Firstly, according to the structural form of the upper cast-in-place beam and the lower cast-in-place beam, rationally design the design drawing of the upper cast-in-place beam and the lower cast-in-place beam sharing a set of brackets;

B. According to the design drawings, pre-embed the embedded parts of the support during the construction of the bored pile of the cap platform and mid-span support foundation;

C. Install the steel pipe at the bottom section of the bracket, and weld the steel pipe at the bottom section of the bracket with the embedded parts of the bracket;

D. After the steel pipe of the bottom section of the bracket is installed, connect the standard steel pipe section of the lower cast-in-place beam support steel pipe for lengthening on the steel pipe of the bottom section of the support, and bolts on the flange are used between the sections and sections of the steel pipe standard section of the cast-in-place beam support of the lower floor connect;

E. After the standard sections of the steel pipes of the cast-in-place beam support on the lower floor are installed, install the horizontal connection system and the longitudinal connection system of the steel pipes on the lower floor in sequence;

F. Install the steel pipe at the top of the cast-in-place beam support column on the lower floor;

G. After the installation of the lower cast-in-place beam support is completed, the upper cast-in-place beam support steel pipe standard section for lengthening is connected to the lower steel cast-in-place beam support column top section steel pipe, and the upper cast-in-place beam support steel pipe standard section and section The sections are connected by bolts on the flange;

H. After the standard section of the steel pipe standard section of the upper cast-in-place beam support is installed, install the horizontal connection system and the longitudinal connection system of the steel pipe of the upper support in sequence;

I. Install steel pipes at the top of cast-in-place beams and columns on the upper floor;

J. Install the upper cast-in-place beam support sand cylinder;

K. Install the distribution beam at the top of the cast-in-place beam support column;

L. According to the hoisting capacity of the crane, assemble the Bailey beam of the upper cast-in-place beam support in groups on the ground, and then use the crane to install the Bailey beam;

M. Preloading of upper cast-in-place beam support;

N. Upper layer cast-in-place beam reinforcement, formwork, concrete, prestressed construction

O. Install the overall lowering device of the Bailey beam, and remove the upper cast-in-place beam support steel pipe;

P. Install the lower cast-in-place beam support sand cylinder;

Q. Install the distribution beam at the top of the cast-in-place beam support column on the lower floor;

R. Lower the Bailey beams of the cast-in-place beam support on the upper floor to the cast-in-place beam support of the lower floor as a whole, and remove the redundant Bailey beams;

S, cast-in-place beam reinforcement, formwork, concrete, and prestressed construction of the lower floor;

T. Remove the lower cast-in-place beam support, and complete the construction of the upper cast-in-place beam and the lower cast-in-place beam.

The present invention is based on the comprehensive consideration of the construction of the upper cast-in-place beam and the lower cast-in-place beam, and the design shares a set of supports to meet the construction of two layers of cast-in-place beams (that is, the upper cast-in-place beam and the lower cast-in-place beam share a set of supports), and the upper cast-in-place beam After the construction is completed, the steel pipes of the upper support and the Bailey beams are lowered to the lower cast-in-place beam support as a whole, so that the upper cast-in-place beam support can be directly converted into the lower cast-in-place beam support, reducing the difficulty of high-altitude construction of the support and reducing large-scale lifting The use time of the equipment is shortened, the construction progress is accelerated, and the damage to the lower cast-in-place beam body due to the construction of the upper cast-in-place beam is avoided. It has the following advantages:

1. The layout of the brackets is combined with the comprehensive consideration of the construction of the upper layer cast-in-place beams and the lower layer cast-in-place beams. The construction of the two layers of cast-in-place beams shares a set of brackets, which avoids the problems of mismatching bracket stiffness and inconsistent foundation deformation, and effectively ensures the integrity of the cast-in-place beam brackets. stability and structural safety;

2. The upper and lower floors of cast-in-place beams share a set of brackets, which can reduce the investment in bracket foundation and brackets.

3. After the construction of the upper cast-in-place beam, the Bailey beam support can be directly lowered as a whole to construct the lower cast-in-place beam, which reduces the difficulty of installing and dismantling the support, and shortens the conversion time of key processes.

4. Avoiding damage to the lower cast-in-place beams.

Description of drawings

Fig. 1 is the support structure schematic diagram of upper floor cast-in-place beam of the present invention;

Figure 2 is a schematic diagram of the I-I direction in Figure 1;

Figure 3 is a schematic diagram of II-II in Figure 1;

Fig. 4 is the support structure schematic diagram of lower floor cast-in-place beam of the present invention;

Fig. 5 is a schematic diagram of direction III-III in Fig. 2;

Fig. 6 is a schematic diagram in the direction of IV-IV in Fig. 2;

Fig. 7 is the schematic diagram of Bailey beam overall lowering device;

Fig. 8-Fig. 26 is the schematic diagram of construction step B-T of the present invention successively.

Detailed ways

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

The construction equipment of the present invention consists of a support foundation bored pile 1, a support steel pipe embedded part 2, a support steel pipe 300, a connecting system 400, a sand cylinder 5, a column top distribution beam 6, a Bailey beam 7, a lowering device 800, and a crane 9 composition.

Bored piles for support foundation 1: Bored piles 20cm larger in diameter than steel pipes are used for mid-span support foundation treatment.

Support steel pipe embedded parts 2: During the concrete construction of the pier side cap and support foundation bored pile concrete, the support steel pipe embedded parts are buried on the top surface.

Support steel pipe 300: According to the total length of the support steel pipe in the design drawing, reasonably divide the support steel pipe into sections. The length of the bottom section steel pipe 301 is determined according to the top elevation of the embedded part. The mouth has a flange, the column top section 303 has a length of 1m, and the top and bottom mouths have flanges, all of which are produced by professional steel structures. The bottom section steel pipe 301 is welded to the embedded part 2, and the bottom section steel pipe 301, the standard section 302, and the column top section 303 are connected by flange bolts.

Connection system 400 : when the support steel pipe is installed at the position of the connection system 400 , connect the steel pipe through the connection system 400 in time.

Sand cylinder 5: According to the design load, it is produced by a professional steel structure manufacturer. The sand cylinder 5 is mainly used to remove the bottom mold, and the sand cylinder is arranged on the top segment 303 of the steel pipe column.

Column top distribution beam 6: According to the calculation, it is processed by combination of section steel, and the column top distribution beam 6 is placed on the sand cylinder 5.

Bailey beam 7: The standard Bailey beam 7 in the rental market, according to the design calculation, the Bailey beam 7 is reasonably arranged, and at the same time, the versatility of the grouping of the upper and lower Bailey beams is considered, so that the upper Bailey beam 7 can be directly converted into Lower Bailey Beam 7 used.

Lowering device 800: each set of lowering device consists of 2 fine-rolled threaded steel bars 801, 6 nuts 802, 2 backing plates 803, 4 movable backing plates 804, 1 lower anchor beam 806, 1 backing beam 807, 1 set Jack equipment 805 consists of one upper anchor beam A808 and one upper anchor beam B809. Finished threaded steel bar 801, nut 802, backing plate 803, movable backing plate 804, and jack equipment 805 are stereotyped products, and the lower anchor beam 806, backing beam 807, upper anchor beam A808, and upper anchor beam B809 are combined and processed by section steel .

Crane 9: According to the on-site working conditions, select the crane 9 whose mechanical properties meet the requirements of the lifting distance.

A construction method for double-layer cast-in-place beams first up and then down, the specific steps are as follows:

A. Firstly, according to the structural form of the upper cast-in-place beam and the lower cast-in-place beam, rationally design the design drawing of the upper cast-in-place beam and the lower cast-in-place beam sharing a set of brackets;

B. According to the design drawings, pre-embed the embedded parts of the support during the construction of the bored pile of the cap platform and mid-span support foundation;

C. Install the steel pipe at the bottom section of the bracket, and weld the steel pipe at the bottom section of the bracket with the embedded parts of the bracket;

D. After the steel pipe of the bottom section of the bracket is installed, connect the standard steel pipe section of the lower cast-in-place beam support steel pipe for lengthening on the steel pipe of the bottom section of the support, and bolts on the flange are used between the sections and sections of the steel pipe standard section of the cast-in-place beam support of the lower floor connect;

E. After the standard sections of the steel pipes of the cast-in-place beam support on the lower floor are installed, install the horizontal connection system and the longitudinal connection system of the steel pipes on the lower floor in sequence;

F. Install the steel pipe at the top of the cast-in-place beam support column on the lower floor;

G. After the installation of the lower cast-in-place beam support is completed, the upper cast-in-place beam support steel pipe standard section for lengthening is connected to the lower steel cast-in-place beam support column top section steel pipe, and the upper cast-in-place beam support steel pipe standard section and section The sections are connected by bolts on the flange;

H. After the standard section of the steel pipe standard section of the upper cast-in-place beam support is installed, install the horizontal connection system and the longitudinal connection system of the steel pipe of the upper support in sequence;

I. Install steel pipes at the top of cast-in-place beams and columns on the upper floor;

J. Install the upper cast-in-place beam support sand cylinder;

K. Install the distribution beam at the top of the cast-in-place beam support column;

L. According to the hoisting capacity of the crane, assemble the Bailey beam of the upper cast-in-place beam support in groups on the ground, and then use the crane to install the Bailey beam;

M. Preloading of upper cast-in-place beam support;

N. Upper layer cast-in-place beam reinforcement, formwork, concrete, prestressed construction

O. Install the overall lowering device of the Bailey beam, and remove the upper cast-in-place beam support steel pipe;

P. Install the lower cast-in-place beam support sand cylinder;

Q. Install the distribution beam at the top of the cast-in-place beam support column on the lower floor;

R. Lower the Bailey beams of the cast-in-place beam support on the upper floor to the cast-in-place beam support of the lower floor as a whole, and remove the redundant Bailey beams;

S, cast-in-place beam reinforcement, formwork, concrete, and prestressed construction of the lower floor;

T. Remove the lower cast-in-place beam support, and complete the construction of the upper cast-in-place beam and the lower cast-in-place beam.

Claims (1)

1. A double-layer cast-in-place beam first up and down support construction method, characterized in that: A. Firstly, according to the structural form of the upper cast-in-place beam and the lower cast-in-place beam, rationally design the design drawing of the upper cast-in-place beam and the lower cast-in-place beam sharing a set of brackets; B. According to the design drawings, pre-embed the embedded parts of the support during the construction of the bored pile of the cap platform and mid-span support foundation; C. Install the steel pipe at the bottom section of the bracket, and weld the steel pipe at the bottom section of the bracket with the embedded parts of the bracket; D. After the steel pipe of the bottom section of the bracket is installed, connect the standard steel pipe section of the lower cast-in-place beam support steel pipe for lengthening on the steel pipe of the bottom section of the support, and bolts on the flange are used between the sections and sections of the steel pipe standard section of the cast-in-place beam support of the lower floor connect; E. After the standard sections of the steel pipes of the cast-in-place beam support on the lower floor are installed, install the horizontal connection system and the longitudinal connection system of the steel pipes on the lower floor in sequence; F. Install the steel pipe at the top of the cast-in-place beam support column on the lower floor; G. After the installation of the lower cast-in-place beam support is completed, the upper cast-in-place beam support steel pipe standard section for lengthening is connected to the lower steel cast-in-place beam support column top section steel pipe, and the upper cast-in-place beam support steel pipe standard section and section The sections are connected by bolts on the flange; H. After the standard section of the steel pipe standard section of the upper cast-in-place beam support is installed, install the horizontal connection system and the longitudinal connection system of the steel pipe of the upper support in sequence; I. Install steel pipes at the top of cast-in-place beams and columns on the upper floor; J. Install the upper cast-in-place beam support sand cylinder; K. Install the distribution beam at the top of the cast-in-place beam support column; L. According to the hoisting capacity of the crane, assemble the Bailey beam of the upper cast-in-place beam support in groups on the ground, and then use the crane to install the Bailey beam; M. Preloading of upper cast-in-place beam support; N. Upper layer cast-in-place beam reinforcement, formwork, concrete, prestressed construction O. Install the overall lowering device of the Bailey beam, and remove the upper cast-in-place beam support steel pipe; P. Install the lower cast-in-place beam support sand cylinder; Q. Install the distribution beam at the top of the cast-in-place beam support column on the lower floor; R. Lower the Bailey beams of the cast-in-place beam support on the upper floor to the cast-in-place beam support of the lower floor as a whole, and remove the redundant Bailey beams; S, cast-in-place beam reinforcement, formwork, concrete, and prestressed construction of the lower floor; T. Remove the lower cast-in-place beam support, and complete the construction of the upper cast-in-place beam and the lower cast-in-place beam.