JP3608751B2 - Temporary fixing method of block in PC precast block method by non-coupler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of temporarily fixing a block in construction work of a structure by a PC precast block method. More specifically, the structure body is divided into a plurality of blocks in advance, and the divided blocks are manufactured at a block production yard provided at the factory or site site, that is, precast, and then the precast blocks are carried to the construction site. Assembling and inserting a tension material (PC steel stranded wire) through a sheath embedded in each block in advance, and introducing the tension force into this, the blocks are integrally coupled and fixed to form a desired structure. In the construction work of pre-stressed concrete precast block method (hereinafter referred to as PC precast block method) by the so-called post-tension method for assembly construction, the blocks are temporarily connected and fixed before the blocks are permanently fixed. Related to temporary fixing method of blocks A. For example, the present invention relates to a method for temporarily fixing a block when a PC bridge is installed by a PC precast block construction method.
[0002]
[Prior art]
FIG. 7 shows the structure of the PC bridge constructed by the PC precast block method. In the figure, reference numeral 54 denotes a tension material in which post tension is introduced into each block and the blocks are integrally coupled and fixed. Conventionally, when constructing a PC bridge by this method, a plurality of blocks A _1, as illustrated bridge girder stigmas portion 51 as a reference in advance piers _50, A 2, _... is divided into A _n, block A was the division ₁ , A ₂ ,... _An are manufactured at a block manufacturing yard provided at a factory or construction site. Then, the blocks A ₁ , A ₂ ,... _An are carried into the site.
[0003]
On the other hand, as shown in FIG. 8, on the column head 51 of the bridge pier 50, a horizontally movable lifting machine (winch 52 a) called a so-called erection nose 52 is mounted and deployed, and the erection nose 52 carries in the site. first Komu hanging the first block _{a 1} to the right and left projecting crossbeam portions 51a and 51a in the stigma portion 51.
[0004]
Then joining the both by applying an adhesive or the like at the interface between the block A ₁ and crossbeam portion 51a of fancy hanging. In this state, the cross beam portion 51 a and the block A ₁ are temporarily fixed using the temporary fixing member 53.
[0005]
When temporary fixing is completed, a tension member 54 (PC steel strand) for introducing poston tension is inserted between the column head 51 and the temporarily fixed block A _1, and tension force is introduced into the tension member 54. is the fixing block a ₁ first, stigmas unit 51, hereinafter, the block a _1, a 2, _... the hanging of a _n, temporarily fixed and showed work of the fixing in FIG. 7 by repeating the order Such blocks are integrally connected and fixed to construct a PC bridge.
[0006]
Incidentally, FIG. 9 shows a process in which five blocks A ₁ ... A ₅ are permanently fixed and a _sixth block A ₆ is suspended and temporarily fixed. A series of construction procedures by suspending, temporarily fixing, and permanently fixing the blocks A ₁ , A ₂ ,... _An are suspended and temporarily fixed on both sides of the pier 50 as shown in FIG. At the same time, there is a case where the main fixing is carried out symmetrically, or a case where the right and left are alternated, that is, an asymmetrical procedure is used. In addition, the arrangement of the tension member 54 (PC steel strand) for introducing the post tension and the so-called permanent fixing and the sheath 55 inserted therethrough takes into account the shape of the cross section of the bridge girder, the division position of the block, etc. It is arranged at the production stage.
[0007]
10, the block _{A 1,} A 2, illustrates a cross-sectional view of a ... _{A n.} A large number of holes shown in the cross-section show an arrangement example of a so-called sheath 55 through which a tension member 54 for introducing post-fixing tension for main fixing is inserted. As a matter of course, these are arranged according to the shape of the cross section of the bridge girder as described above, and the pipes are buried in the manufacturing stage of the block itself.
[0008]
As explained above, this PC precast block construction method is understood from the explanation of the PC bridge as an example.
(1) Since the block is manufactured at a factory or on-site site, the management can be sufficiently performed, and a block with a highly accurate member cross section can be manufactured.
(2) Ancillary works can be developed in parallel with the production of blocks.
(3) Since the sheath of the cable for integrating the blocks is arranged in advance in the block manufacturing process, the manufacturing is very easy.
Due to these advantages, compared to bridge structures constructed by conventional construction methods, it is not only excellent in manufacturing quality, but also in workability, shortening the construction period, and innovative design, and is evaluated as a building structure such as a bridge.
[0009]
[Problems to be solved by the invention]
However, in this method, the blocks need to be temporarily fixed in order before the divided blocks are permanently fixed. As the means, conventionally, as described above, it is connected and temporarily fixed using the temporary fixing member 53 or the like. For example, referring to FIG. 8, the point will be specifically described. A plurality of protrusions 56 and 56 are provided in the column head 51 in advance. Similarly, protrusions 57 and 57 corresponding to the protrusions 56 and 56 are also provided in the block A ₁ (hereinafter, all blocks) to be connected. Then, for example, a tie rod bar-like joint member (PC steel material) 58 is passed between the left and right projections 56, 56 and projections 57, 57, and both are coupled and temporarily fixed via the joint member 58. I am doing so.
[0010]
Other blocks A ₁ including stigmas unit _51, A 2, _... are provided in advance notch to A _n, attaching the joint member by use of the notch, ligated, Toka is temporarily fixed, and further block A _1, a 2, _... in advance embedded connecting fitting to a _n itself connected by using this, so that temporarily fixed.
[0011]
For this reason, the temporary fixing work is labor intensive as well as manpower, and is cumbersome. In particular, one block is temporarily fixed, and every time the main fixing is completed, that is, every time the post-tension introduction work is completed, the temporary fixing member 53 is removed and transferred to be used as the next temporary fixing member 53. I am doing so. As a result, a great amount of labor and labor are required for the temporary fixing work by the temporary fixing member 53.
[0012]
Further, in the conventional temporary fixing system, capital unit 51 and blocks A _1, A 2, or provided with a projection portion or a notch on _... A _n, because of the embed joint member, the structure itself including the portion However, there is a problem that further consideration is required for the strength reliability. The present invention eliminates the member 53 that has been used as a temporary fixing connection means from the viewpoint of improving such assembly work problems, structural strength, safety, and workability. It was developed for the purpose of providing a temporary fixing method using a coupler method.
[0013]
[Means for solving the problems]
Therefore, in order to achieve the above object, what kind of means has been taken is to divide a desired concrete structure into a plurality of blocks in advance, and sequentially connect the divided blocks to a structure part to be fixed. In the PC precast block construction method, the temporarily fixed block is fixedly fixed integrally via a post tension cable, and a prestressed precast concrete structure is built by a so-called post tension method.
(1) First, a structure part to be fixed and a sheath through which a temporary fixing cable is inserted are provided in advance in each block, and a temporary inlet is provided on the sheath inlet side of the structure part to be fixed. A hypothetical attachment that temporarily clamps a fixing cable (similar to a tensioning material used for main fixing) and a cable drum around which a temporary fixing cable is wound are installed.
First, the first block is hung on the side of the structure portion of the fixed portion and the cable is pulled out from the cable drum. Through the assumed attachment on the structure portion side to be the fixed portion and the sheath of the block The end of the cable, that is, the tip is pulled out toward the front end of the block (first step).
(2) Next, a jack is connected to the front end of the cable drawn out to the front end of the block, and a tension force is introduced into the cable with the assumed attachment as a reaction point, and the block is connected to the structure portion of the fixed portion. It is pulled to the side and temporarily fixed by a cable (second step).
(3) In this state, a tension material is inserted between the structure portion of the fixed portion and the block to introduce post tension, and both are permanently fixed and fixed (third step).
(4) When the main fixing by the introduction of the post tension is completed, the cable is released from the assumed attachment on the structure side, the jack is removed from the tip of the cable, and the next block is fixed to the main fixing block. Suspend to the side, insert the tip of the cable removed from the jack into the sheath of the suspended block, pull it out to the front end, reconnect the jack to the tip of the pulled-out cable, and tighten the cable Force is introduced to temporarily fix the next block (fourth step).
(5) Hereinafter, the second step to the fourth step in which the jack is reconnected to the leading end portion of the drawn cable and the block is temporarily fixed are sequentially repeated, and the block itself is temporarily fixed using the temporary fixing cable. There is something to do.
[0014]
In addition, while the structure part used as the said to-be-fixed part and the sheath which penetrates the cable for temporary fixing provided in each block are each provided in a plurality of positions, the assumption attachment and jack of the cable are also respectively corresponding to this This is because a plurality of groups are used.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Furthermore, it demonstrates concretely based on the case where embodiment of this invention is applied to PC bridge. First, FIG. 1 shows that a PC bridge based on the PC precast block method is used to temporarily suspend the first blocks A ₁ and A ₁ of the bridge girder divided in advance on the left and right sides of the column head 51 of the pier 50 using the erection nose 52. It shows the first step of fixing. That shows a first working step Komu hanging to crossbeam portions 51a and 51a side of the overhang to the left and right column capital portion 51 which corresponds to the structure of the fixed portion of the block A ₁ and A _1.
[0016]
Before the blocks A ₁ and A ₁ are suspended, the upper and lower webs of the left and right cross beams 51a and 51a that form the column head 51 in advance are respectively connected to corners in the cross beams 51a and 51a. Sheaths 2 and 2 through which the cable 1 for temporary fixing leading from the left corner to the right end surface is inserted toward the end surface, that is, from the right corner to the left end surface.
[0017]
Further, the temporary fixing cables 1 were temporarily clamped at the corners where the cables 1 were to be inserted, and assumed attachments 3 and 3 each having a function as an anchor head were installed. Furthermore, cable drums 4 and 4 around which the cable 1 for temporary fixing is wound are arranged inside the left and right cross beam portions 51a and 51a.
[0018]
FIG. 2 is an enlarged detailed view of the portion B in FIG. 1, and is a detailed view of mounting the assumed attachment 3 that is installed at the corner of the cross beam portion 51a and functions as the anchor head of the cable 1 for temporary fixing. . Reference numeral 3 a denotes an attachment pressure plate for the assumed attachment 3.
[0019]
3, after elaborate hanging blocks _{A 1} and _{A 1} by Election nose 52, ie the process is temporarily fixed to the block _A 1, _{A 1} on the side surface of the crossbeam portions 51a and 51a from the state of FIG. In other words, from the cable drums 4 and 4 installed in the cross beams 51a and 51a, the assumed attachments 3 and 3 in which the ends (tips) of the temporarily fixing cable 1 are provided at the corners, respectively, and then the blocks A ₁ and A ₁ is pulled out to the left and right end face side through the sheaths 2 and 2 (see FIG. 1), and the jacks 5 and 5 are connected to the terminal via the assumed attachments 3b and 3b (tension side) as shown in FIG. The jacks 5 and 5 are actuated, tension is introduced into the cable 1 with the assumed attachments 3 and 3 as reaction points, respectively, and the blocks A ₁ and A ₁ are drawn to the column head 51 side and temporarily fixed. The process is shown.
[0020]
Figure 4 is a block A _1, A 2 shown in FIG. 10 previously, _... is the same as the cross-sectional structural view of A _n, where the different points blocks A ₁ shown in, as previously described temporary fixing on relation to fixed using cable 1 of use, each dedicated sheath 2 inserted through the cable 1 in advance blocks a ₁ temporary _fixing, a 2, _... and arranged in fabrication steps near the four corners of a _n It is that you are. Specifically, as shown in the figure, a total of four sheaths 2 are arranged near the four corners.
[0021]
As described in FIG. 3, first, when temporarily fixing work for the first column capital portion 51 side of the block A ₁ and A ₁ is completed, a conventional street cable for the fixing between both, that tension member (PC steel The stranded wire is inserted and set, post tension is introduced, and the blocks A ₁ and A ₁ are permanently fixed to the column head 51 side (see FIG. 9). At the time when the main fixing work of the blocks A ₁ and A ₁ is completed, the assumed attachments 3, 3b and 3, 3b in which the cable 1 is temporarily fixed by the jacks 5 and 5 are released.
[0022]
Next, when the removal of the jack 5 from the temporary fixing cable 1 and the release of the cable 1 from the assumed attachments 3 and 3 are finished, the next blocks A ₂ and A ₂ are as described in FIG. Suspend using the erection nose 52. When the operation is completed, after inserting the end of the cable 1 removed from the jack 5, that is, the distal end portion into the sheaths 2 and 2 of the suspended blocks A ₂ and A ₂ , respectively, the hypothetical attachment to the distal end portion is performed again. The tools 3b and 3b are attached and the jacks 5 and 5 are connected. Next, the cable 1 is tensioned as described with reference to FIG. 3, and the block A ₂ is temporarily fixed to the outside of the A ₁ , and then the main fixing operation is performed in that state.
[0023]
Hereinafter, the hanging of the block, temporarily fixed and, by repeating the operations of the present fixing sequentially advance divided each had been blocks A _1, A 2, _... coupled integrally to A _n, the desired A PC bridge structure was constructed.
[0024]
Incidentally, FIG. 5 shows a process of permanently fixing the block A _{1 and the} subsequent blocks A ₃ , releasing the temporary fixing cable 1, removing the jack 5, and suspending the next block A ₄ .
[0025]
Furthermore 6, subsequent to step of FIG. 5, the block A ₄ and A _4, through the temporary fixing cables 1, showing the step was temporarily fixed block A ₄ and A ₄ by operating the jack 5 Is.
[0026]
【Example】
The block temporarily fixing method according to the present invention is characterized in that the block is temporarily fixed by the above-described procedure. As in the prior art, a joint member (coupling) or the like as a temporary fixing means is assembled in advance to the block or the like. This method is not adopted. In other words, it is temporarily fixed by a non-coupler method.
[0027]
In the embodiment, as shown in FIG. 1 and FIG. 3 and subsequent drawings, the temporary fixing cable 1 is provided with two left and right cable drums 4 and temporarily fixed using a total of four cables 1. I did it. Therefore, the temporary fixing member 3 to temporarily fix the cable 1 is provided inside the upper and lower corners of the crossbeam portions 51a and 51a to form a capital portion 51 left and right blocks A ₁ and A ₁ as shown.
[0028]
Then, the cable 1 from the cable drums 4 and 4 installed on the right side is guided to the blocks A ₁ , A ₂ ,... _An side through the upper and lower webs of the left lateral girder 51a, and installed on the left side. cable 1 from the cable drum 4 and 4 are block a ₁ via the upper and lower webs of the right crossbeam portions 51a _{respectively,} a 2, and configured to direct to _... a _n.
[0029]
As a result, in this embodiment, the block A _1, A 2, _... temporary fixing of A _n, the fixing is stigmas portion 51 piers 50 adapted to symmetrically construction to the left and right as a starting point. In other words, the blocks are assembled and installed symmetrically. However, it is not limited to this. It is of course possible to assemble and install in a cantilevered manner, and it is also possible to apply asymmetrically.
[0030]
Further, as the assumed attachment 3 for temporarily clamping and temporarily fixing the cable 1, that is, the assumed attachment 3 shown in FIG. 2, when the tension is applied to the inserted cable 1, the cable 1 is automatically clamped. On the contrary, when the tension force was loosened, the assumed attachment 3 having a wedge mechanism that automatically releases the clamp was used. As the temporary fixing cable 1, a PC steel strand was used as in the case of the main fixing and the cable, and as the jack 5 for introducing tension to the cable 1, a center hole type jack was used.
[0031]
【The invention's effect】
As described in the above embodiments, the block temporarily fixing method according to the present invention uses a cable rather than a temporary fixing method using a PC steel material using a bracket or a notch as seen in conventional temporary fixing means. Since the non-coupler method is a temporary connection fixing method, the block assembly work is better and more effective than the conventional block method. In particular, since it is not necessary to provide a notch part or a buried metal fitting as temporary fixing means in each block, the superiority of the PC precast block can be further improved, and structural strength anxiety can be eliminated. In addition, a cable made of PC steel wire is used as a member that divides the main role of temporary fixing, and this is guided through a sheath installed in advance in each block to introduce tension. In the case of a bridge that is easy to install and handle, the bridge girder cross-sectional shape changes as seen on PC bridges, that is, formed on an arch that curves the lower surface, the cable can be guided along the lower curved line, An effect not seen in the prior art that can be applied without difficulty as a temporary fixing method can be exhibited.
Further, after the temporary fixing operation is completed, it is possible to add a post-tension to the bridge itself by introducing a tension force to the cable itself and leave it as a member element as a PC bridge.
[Brief description of the drawings]
FIG. 1 is a process diagram of hanging main girder blocks divided in advance on both left and right sides of a pier head.
FIG. 2 is an enlarged detailed view of a portion B in FIG. 1 and shows a mounting portion of the assumed attachment.
FIG. 3 is a process diagram for temporarily fixing a block to a side surface of a column head.
FIG. 4 is a sectional structural view of a block.
FIG. 5 is a process diagram in which the main fixing work of blocks A ₁ ... A ₃ is completed, the cable is released from the assumed attachment, the jack is removed, and the next block A ₄ is suspended.
FIG. 6 is a process diagram in which blocks A ₁ ... A ₄ are temporarily fixed.
FIG. 7 is a structural diagram of a PC bridge by a PC precast block method.
FIG. 8 is a process diagram for temporarily fixing divided blocks to both sides of the column head of the pier.
FIG. 9 shows a process chart in which the divided blocks A ₁ ... A ₅ are permanently fixed and the _sixth block A ₆ is suspended and temporarily fixed.
FIG. 10 is a sectional structural view of a conventional block.
[Explanation of symbols]
A ₁ , A ₂ , ... A _n ... Block (bridge girder)
50 ... pier (pier)
51 ... Column head 51a ... Cross girder 52 ... Erection nose 52a ... Lifting machine (winch)
53 ... Temporary fixing member 54 ... Tensile material 55 ... Sheaths 56, 57 ... Protrusion 58 ... Tie rod bar 1 ... Cable (for temporary fixing)
2 ... Sheath 3 ... Assumed wear 3a ... Supporting pressure plate 3b ... Assumed wear (tension side)
4 ... Cable drum 5 ... Jack (Center hall type)

Claims (2)

A concrete structure is divided into a plurality of blocks in advance, and the divided blocks are sequentially coupled to a structure part to be fixed and temporarily fixed, and a post-tensioning tension material is passed through the temporarily fixed block, and tension is applied thereto. In the PC precast block method of building a prestressed precast concrete structure in which force is introduced and the block is fixedly fixed integrally,
The structural portion to be fixed portion and a sheath through which a temporary fixing cable is inserted in advance are provided in each block, and the temporary fixing cable is temporarily placed on the sheath inlet side of the structural portion to be fixed portion. A hypothetical clamp that clamps the cable and a cable drum wrapped with a temporary fixing cable,
The first block is hung on the side of the structure part of the fixed part, the cable is pulled out from the cable drum, and the assumed attachment on the structure part side to be the fixed part and the sheath of the suspended block are provided. A first step of pulling the leading end of the cable to the front end of the block via,
A jack is connected to the front end portion of the cable drawn out to the front end portion of the block, and a tension force is introduced into the cable by using the assumed attachment as a reaction point to the cable, and the block is pulled toward the structure portion side of the fixed portion. A second step of fixing;
In this state, a third step of introducing a post tension between the structure portion of the fixed portion and the block and permanently fixing both of them together;
Release the cable from the assumed attachment on the structure side, remove the jack from the tip of the cable, suspend the next block to the side of the permanently fixed block, and attach it to the sheath of the suspended block. A fourth step of inserting the leading end of the cable removed from the jack and pulling it out to the front end, reconnecting the jack to the leading end of the pulled out cable, and temporarily fixing the next block;
Hereinafter, the block fixing method in the PC precast block construction method using a non-coupler, wherein the second step to the fourth step are sequentially repeated, and the block is temporarily fixed integrally through a cable. The structural part to be fixed part and the sheath through which the cable for temporary fixing provided in each block is inserted are provided at a plurality of positions, respectively, and a plurality of assumed fittings and jacks of the cable corresponding thereto are used. The temporary fixing method of the block in the PC precast block construction method by the non-coupler of Claim 1 characterized by the above-mentioned.

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