KR101478131B1 - Construction Method of Precast Pier - Google Patents

Abstract

The present invention relates to a prefabricated bridge pier which makes a pier bridge, which is a substructure of a bridge, using a precast block.
The present invention eliminates the need for a separate connecting device (coupler or steel bar) for connection between precast upper and lower blocks, instead of eliminating the connection parts of the upper and lower blocks, Shrinkage concrete, etc.) to complete the prefabricated bridge pier. The above-mentioned stress transmission is a structure in which stress is transmitted by the shear frictional force between vertical steel bars arranged in a horizontal plane.

Description

{Construction Method of Precast Pier}

The present invention relates to a construction method of a prefabricated bridge pier which makes a pier bridge, which is a substructure of a bridge, by using precast blocks.

In recent years, there has been an increasing interest in prefabricated structures using precast concrete in order to meet the demands for large-scale, high-strength, lightweight, long life, and functionalization of concrete structures.

Especially in recent years, precast prefabrication technology has been actively applied to bridge substructure. This is because the precast prefabricated technology significantly solves the problems that arise due to the construction of conventional on-site concrete.

The prefabricated construction system is actively applied to the following main factors. First, precast prefabricated bridge piers are pre-fabricated in a well-equipped environment, so that there is no restriction in the field installation and quality and economical efficiency can be improved.

Second, the safety of the construction site can be improved by manufacturing the bridge member in the manufacturing site in advance.

Third, environmental damage can be minimized because it can reduce the use or use period of large equipment in the field.

Finally, there is an advantage that quality can be increased and life cycle cost can be reduced.

The prefabricated pier construction method is to build each block at the factory or site, and then build up the pier by stacking the blocks in the field. The connection between the upper and lower blocks is made by integrating the joints using steel bars or steel rods.

[Document 1] 10-0099113, prefabricated pier and column structure and method of construction

[Document 2] 10-2000-0041440, Construction method of pier structure using precast concrete block and its structure

[Literature 3] 20-0324563, prefabricated pier structure

[Patent Document 4] 10-0549649, Pier structure by precast assembly structure

[Literature 5] 20-0414671, Concrete-filled prefabricated column and its assembling structure

[Patent Document 6] 10-0605302, prefabricated pier structure

[Literature 7] 20-0424776, Concrete piers using precast concrete hollow tube formwork

[Literature 8] 10-0639255, shear resistance duct and connection structure of precast member using the same

[Patent Document 9] 10-0643575, Prefabricated Precast Composite Pier Structure and Construction Method

[10] 10-0704874, A prefabricated concrete pier structure reinforced with steel pipe

[Literature 11] 10-0704737, Precast underwater pier structure

[Literature 12] 10-0713690, A prefabricated pier using internal confined hollow concrete filling unit and its construction method

[Patent Document 13] 10-0738999, Precast Concrete Segment Having Assembly Structure Using Steel Duct and Its Connection Assembly Structure

[Literature 14] 10-0762166, Precast pier structure and its construction method

[Literature 15] 10-0776774, Manufacturing Method of Precast Concrete Pier Segment with Assembly Structure Using Steel Duct

[Literature 16] 10-0804125, Connecting device of precast concrete member, prefabricated pier structure using the same and method of construction thereof

[Patent Literature 17] 10-0860591, Construction Method of Vertical Structure Using PC Block

[Literature 18] 10-0895033, Precast column unit and method of constructing column structure using the same

[Literature 19] 10-0909277, Pillar foundation with steel pipe and assembly structure of pier using it

The most important thing in the prefabricated construction method is the interblock connection. Blocks referred to in this assignment are copings, pillars, and bases (field castings). That is, the inter-block connection means the connection between the coping and the column, the column and the column, and the column and the foundation.

In the conventional assembly method, blocks are piled up and down, and the connection between the blocks is made using reinforcing bars or steel rods, and the connection is integrated using a coupler or post tension.

In the above methods, the connection part is concentrated on the cross section between the block and the block, so that it is very important to be careful when constructing the connection part. Further, troublesomeness and precision of the operation are required when applying the coupler and post tension.

In order to solve the above problems, the present invention is characterized in that a separate connecting device for connection between precast upper and lower blocks is omitted. In other words, only foundation concrete is laid in the field, and then only the blocks are stacked. In this case, inter-block joints can be connected between blocks by simply filling the filler materials (eg, non-shrinkage mortar or epoxy or shrinkage concrete) , It does not require the troublesome and precise construction of the existing connection part construction.

The bridge is designed mainly to receive compressive force at all times, but it is designed as a structure that receives compression and bending at the same time considering eccentric load due to wind load and upper vehicle, especially, seismic load during earthquake.

Unlike bridge piers which are made integral by site casting, the connection part between blocks of a pier constructed by stacking blocks must be able to withstand the tensile force generated by horizontal shear force and bending, and the connection part construction should be as simple as possible.

In the present invention, the connecting block between the upper and lower blocks is formed into a concave-convex shape so that the upper block and the lower block are fitted to each other, and the horizontal shearing force is resisted by the unevenness.

For tensile strength: Vertical bars (cast iron bars) that resist tensile forces are not directly connected between blocks, but vertical bars are placed on top of each other at the interblock joints, while shear frictional forces are introduced between horizontally spaced vertical bars So that the tensile force is transmitted. To do this, you only need to fill the gap with filler after installing the block. For more reliable introduction of shear frictional force, grooves may be formed in the inner side surface of the concave / convex portion, or a shear connection member (for example, reinforcing steel) may be installed to form a block so as to serve as a shear key.

Also, the first pillar block installed after the foundation concrete pouring is the same as above, but since the difference in the stiffness between the foundation and the pillar is large, concrete is filled in the pillar with a certain height in consideration of earthquake etc. The vertical load, which rides down the column from the top, is also transmitted through the concrete filled in by the shear friction, so that the vertical load is uniformly distributed on the foundation.

Also, the method of connecting the coping block and the column block is the same as that of introducing the shear frictional force by the interblock filler as described above.

In case of T-type bridge pier, the coping block is designed to be empty in order to reduce its weight when it is mounted with a crane or the like. Such a coping block plays a role as a main part as well as a form and a tie. The construction procedure is to install the coping block, fill the gaps between the blocks with filler, put the manufactured reinforcing net into the copping with a crane or the like, and then put the concrete and cure it to complete the coping. The feature of the coping block is that the shear connection material (eg reinforcing bar) is installed on the inner side of the coping during manufacture, so that there is no need to separately connect the reinforcing bar to be inserted and the reinforcing bar inside the coping, This is because the installed shear connectors can integrate the coping block with the concrete to be placed thereafter.

In the case of a single stock pier, the load of the coping block is not large. Therefore, by simply fitting the coping block onto the column block and filling the filler, the pier construction is completed.

The prefabricated bridge piers according to the present invention may have a slightly smaller aesthetic value compared to existing bridge piers due to the outer projections exposed on the side surfaces of the columns,

This assembly pier is easy to construct because it builds up the connection part by stacking the blocks and filling the filling material only. In addition, it is economical because there is no need for a separate connecting device (such as a coupler or a steel bar).

Figure 1 shows the overall view of the prefabricated pier
Fig. 2 shows the overall view of the prefabricated pier with low pier height
3 shows a block-to-block connection (TYPE A)
Fig. 4 is a block diagram showing the inter-block connection (TYPE A)
Fig. 5 is a block diagram showing a block-to-block connection (TYPE A)
FIG. 6 is a block diagram illustrating an inter-block connection (TYPE B)
Figure 7 shows an example of a block-to-
Fig. 8 is a block diagram of a block-to-block connection (TYPE B)
FIG. 9 is a cross-
FIG. 10 is a schematic diagram of a connection-to-
FIG. 11 is a view showing a connection and a coping block detail of a coping block
12 shows the connection between the base and the column block
Fig. 13 shows an example of connection between a foundation and a column block
Fig. 14 is a cross-sectional view showing a cross-

For the sake of explanation, the prefabricated bridge pier has selected a typical circular bridge pier, and an embodiment thereof will be described with reference to the accompanying drawings.

FIG. 1 is an overall view of a prefabricated bridge pier proposed by the present invention, in which a pillar block 100 of the same size (height) is stacked and a total pier height is matched by using an upper pillar block 130 having a different size .

2 shows a prefabricated bridge pier using only one pillar block 131 when the pier height is low as in the case of urban areas.

FIG. 3 shows the form of the block 100 which is type A type and the connection method between the blocks.

The block-to-block connection method is carried out by inserting the upper block 100 with a crane or the like into the insertion port 110 of the block 100, and filling the gap with a filling material. At this time, the creeping work is performed by the worker on the outer projection 111 side and the worker goes down through the upper central hole of the upper block on the inner projection 112 side.

4 is a connecting portion of the type A-type block 100, which shows an example of the installation of a main section of a block cross section. As shown in the embodiment of the present invention, the vertical reinforcement 120 resists the bending tensile force generated in the block itself, and the bending tensile force generated in the inter-block joint portion resists the outer vertical reinforcement 121, (120 and 121) is transmitted by the transfer frictional force between the upper and lower blocks, and the shear frictional force is transmitted through the upper block-filler (113) -lower block. The inner protrusion 112 and the outer protrusion 111 and the outer vertical reinforcement 121 resist the horizontal shear force together. The horizontal reinforcing bars 122 also resist the shear stresses and shear stresses generated from the upper blocks. Also, when two or more column blocks are used in one column, the bending moments acting on the columns vary depending on the vertical position. In this case, the diameter and the number of the vertical bars 120 used for each column block It is possible to design economically since there is no problem in connection between blocks.

In order to introduce a more reliable shear frictional force at the connecting portion between the upper and lower blocks, a horizontal distance between the upper and lower blocks is increased at the connecting portion as shown in FIG. 5 at the time of preliminary manufacturing, and a shear connecting member 123 Alternatively, the pre-groove 114 may be provided in advance to serve as a shear key as shown in FIG. 7, or both of the above methods may be applied together.

6 shows the connection of the type B block 130. Fig. The blocks 112 are removed from the type A block 100 and only the outer protrusions 111 are used to simplify the block production. The use of the type A and type B distinction can be selected at the stage of structure review during design. In order to increase the shear frictional force at the connecting portion between the blocks, the type B can also be provided with the shear connection member 123 (see FIG. 8) and the front end groove 114 (see FIG.

As shown in FIG. 9, the connection between the coping block 200 and the column block 130 is the same as that of the type B block 130 described above.

As shown in FIG. 11C, the connection between the blocks 130 and 200 secures the space 205 between the coping block 200 and the column block 130 so that the connection can be confirmed and the filling material can be injected.

FIG. 11 shows a detailed view of the coping block 200. FIG. The coping block itself acts as a dormer and a formwork, and at the same time, it can share the role of the main part of copping. First, the inside of the coping is made empty when the coping prefabrication is made. At that time, the inside of the coping inner joint (210, reinforcing bars) is installed on the inner side to integrate with the concrete to be laid later. In this way, when the reinforcing net 220 is inserted, only the concrete is installed without the need of connection work with the coping block, so that the placed concrete and the coping block behave integrally with each other. The above object is achieved by a method for reducing the weight of a coping block so that a crane mount can be performed.

10 shows a coping block 230 of a stock pier, which is completed by filling the block 230 with a filler. It is no different as a coping that receives the acupressure of the bridge support.

Next, as shown in FIG. 12, the bases 300 and 300 are connected to the column blocks 100 and 130 by first putting the bases in place. At this time, holes are formed in the upper surface of the bases 300 so that the column blocks can be inserted, .

13 is a view for effectively transferring the vertical load transmitted from the upper portion to the foundation by increasing the shear frictional force between the base 300 and the column block 100. [ Inside the column block 100, the concrete 302 is laid to reduce the large stiffness difference between the column block and the foundation in preparation for an earthquake. The vertical load is transmitted to the foundation through the lower end of the column block, The shear connection member 123 is installed so that the vertical load can be transmitted to the foundation through the concrete 302 laid.

The vertical reinforcing bars 301 are reinforced bars embedded in the foundation so as to smoothly transmit loads between the column blocks and the foundation through the inner concrete 302.

In order to increase the shear frictional force between the blocks, the shear connection member 123 and the shear grooves 114 described above may be installed at the connecting portions between the blocks when the coils and the columns, the columns and the columns, and the bases are connected to each other .

The following is a description of FIG.

In order to prevent the blocks from moving in position until the filling material filled in the gap between the blocks is hardened, it is necessary to prevent the blocks from moving in position, Temporary fixing between upper and lower blocks may be necessary during construction. At this time, provisional fixing is possible by using a plurality of temporary fixing bars (401) having screws at both ends of the reinforcing bars. First, the block 410 is passed through a hole 410 for temporarily fixing the reinforcing bar, which is necessary for temporarily fixing the lower block in the vertical direction inside the cross section. In order to temporarily fix the block to the upper block, a connection reinforcing bar 403 is inserted into the upper uneven surface 420 (the upper block supporting surface, the hatched surface of the section A-A) of the block. In the following method, a plurality of temporary fixing bars 401 are vertically connected to the connection reinforcing bar 403 provided at the base using a coupler. The column block is inserted so that the reinforcing bar 401 passes through the insertion hole 410 in the column block. The reinforcing bars 401 passing through the block and coming off the uneven surface 420 are fastened with nuts 405 to temporarily fix the blocks. Fill the gap between blocks with filler. Repeat the previous,,, to build the next blocks and complete the prefabricated bridge pier.

Since the reinforcing bar used above is not a structural reinforcing bar, it is not necessary to separately fill the voids of the reinforcing bars 401 and the insertion holes 410. Only a few holes 410 are sufficient for temporary fixing, The loss of the receiving compression section is negligible.

It is to be understood that the scope of the present invention should not be construed as being limited to the above description, and all of the technical spirit of the present invention is included in the scope of the present invention.

100 - Column block
111 - Outer projection
112 - Inward protrusion
113 - Filler
114 - Shear groove
120 - Vertical rebar (cast iron)
121 - Outer vertical reinforcement
123 - Shear connector
200 - coping block
210 - Coping internal shear connector
300 - Foundation
401 - Temporary Fixed Reinforcement
403 - Connecting bars

Claims (6)

As a method for constructing a bridge pier by piling up a plurality of column blocks 100,
The upper end of the column block 100 has a shape in which the outer protrusion 111 having a sectional size larger than the lower end diameter of the column block 100 exists so that a lower portion of the column block stacked on the upper side can be inserted;
The lower end surface of the column block 100 inserted into the space surrounded by the inner surface of the outer protrusion 111 of the column block 100 and the outer protrusion 111 is provided with a protruded shear connection member 123 or a concave shear A groove 114 is formed;
Stacking the upper and lower column blocks so as to fit into the space surrounded by the outer protrusion 111 of the lower row block located at the lower side of the lower row of the upper row block; And
And filling the gap between the lower portion of the male block and the inner surface of the outer projection of the lower block into a space surrounded by the outer protrusion (111) of the lower block to cure the filler.
The method according to claim 1,
The lower portion of the column block 100 has a hollow cross section in which a hollow is formed;
At the upper end of the column block 100, inner protrusions 112 to be inserted into hollows of the column blocks stacked above are formed at intervals corresponding to the lower thickness of the column blocks from the inner surface in the lateral direction of the outer protrusions 111 The upper end of the pillar block 100 has a shape in which a concave insertion hole 110 is formed in an interval between the inner protrusion 112 and the outer protrusion 111;
A front end connecting member 123 or a concave front end groove 114 protruding from the outer surface of the inner protrusion 112 in the lateral direction is formed;
Wherein the filling material is filled in the gap between the outer surface of the inner protrusion (112) of the lower block and the lower portion of the block, and is hardened.
delete 3. The method according to claim 1 or 2,
After the upper and lower column blocks are laminated and filled with filler material and cured,
And the lower end thereof is formed with a portion to be fitted in a space surrounded by the outer protrusion 111, The coping block 200 having a structure in which the shear connection member is protruded on the empty inner surface is placed on the top of the column block 100 at the uppermost position stacked so that the lower end of the coping block 200 is positioned at the uppermost position of the column block 100 The outer protrusion 111 of the outer case 111;
Inserting a reinforcing net (220) into the empty interior of the coping block (200); And
Further comprising the step of placing the concrete in the inside of the coping block (200) and filling the inside of the coping block (200) so that the reinforcing net (220) is embedded.
3. The method according to claim 1 or 2,
Prior to the step of stacking the upper and lower column blocks,
Fabricating the foundation (300) with the pouring concrete so that a hole through which the lower end of the pillar block (100) can be inserted is formed on the upper surface; And
Inserting the lower end of the pillar block (100) into a hole formed in the upper surface of the base (300); And
Further comprising the step of integrating the foundation (300) and the column block (100) by placing concrete in the column block (100) installed on the foundation (300).
3. The method according to claim 1 or 2,
Prior to the step of stacking the upper and lower column blocks, the upper and lower column blocks are formed with holes 410 for inserting temporary fixing bars in the vertical direction inside the section;
A connection reinforcing bar 403 is fixedly installed on a horizontal bottom surface 420 in a space surrounded by the outer protrusion 111 so as to protrude vertically;
When the upper and lower pillar blocks are stacked so that the lower part of the pillar block is fitted into the space surrounded by the outer protrusion 111 of the lower pillar block located at the lower side,
Coupling the lower end of the temporary fixing bar 401 with a connecting reinforcing bar 403 protruding from the bottom surface 420 of the lower block, using a coupler;
Stacking the temporary block on the lower block so that the temporary fixed block 401 is inserted into the temporary fixed reinforcing bar insertion hole 410 formed in the temporary block; And
A step of tightening the nut 405 to the temporarily fixed reinforcing bar 401 protruding from the upper block to the upper end to temporarily fix the stacked upper and lower column blocks and then filling and filling the filling material. Construction method of piers.

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