JPH0665907A - Building method for cylindrical structure - Google Patents

Abstract

PURPOSE:To assemble the structure without any trouble even when there exists some positional deviation in the circumferential direction of a spot into which a shearing key is fitted. CONSTITUTION:A key reinforcing material 10 is interposed in a key formation chamber produced by key formation cavities 5 and 6 preliminarily opposed to each other on the joint area of upper and lower part precast concrete blocks 2 where the blocks 2 are stacked. Mortar is filled up into the key formation chamber 9 by way of an injection hole 12 and a discharge hole 13, thereby forming a shearing key.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a tubular structure used for a PC well, a bridge pier, or the like used as a foundation of a structure.

[0002]

2. Description of the Related Art Conventionally, a tubular structure such as a PC well is shown in FIG.
And, as shown in FIG. 6, a precast concrete block 2 is formed in the hole while drilling a hole under the ground 21.
The two were stacked, and the shear key 23 on the upper surface of the lower precast concrete block 22 was fitted into the concave portion 24 on the lower surface of the upper precast concrete block 22 for connection.

[0003]

However, in such a conventional method for constructing a tubular structure, the assembly is impossible unless the shear key 23 of each precast concrete block 22 and the concave portion are aligned in the circumferential direction. There was a problem that became.

Further, since the shear key 23 needs to have a certain strength or more, it is necessary to embed reinforcing reinforcing bars 25 and 26 inside the shear key 23 and outside the concave portion with which the shear key 23 fits. Was inefficient and inefficient. It is also possible to use high strength concrete to increase the strength of the shear key, but this causes a problem that the cost is too high because it is integrally molded with the entire block.

The present invention has been made for the purpose of solving various conventional problems as described above.

[0006]

The means of the present invention for achieving the above object will be described as follows.

According to a first aspect of the present invention, there is provided a method for constructing a tubular structure, comprising stacking tubular precast concrete blocks and fixing the upper and lower precast concrete blocks by a joining method having a shear key function. The upper and lower precast concrete blocks are provided with key forming recesses facing each other in advance on their joint surfaces, and a key reinforcing steel material is interposed vertically in the key forming chamber formed by these upper and lower key forming recesses. It is characterized in that the upper and lower precast concrete blocks are stacked, and then the key forming chamber is filled with mortar to form a shear key.

According to a second aspect of the present invention, tubular precast concrete blocks are stacked, the upper and lower precast concrete blocks are fixed by a joining method having a shear key function, and the upper and lower precast concrete blocks are rebar. In the method of constructing a tubular structure to be connected with, the upper and lower precast concrete blocks are provided with key-forming recesses that face each other in advance on their joint surfaces, and the precast concrete blocks that are on the top, The lower end is made to communicate with the key-forming recess on the lower surface of the sleeve so that the sleeve is pre-built therein, and the upper end of the lower inter-block connecting bar inserted into the lower precast concrete block and the upper precast concrete. Upper block inserted in the block While inserting the lower ends of the connecting bars, the upper and lower precast concrete blocks are stacked by vertically interposing a key reinforcing steel material in the key forming chamber formed by the upper and lower key forming recesses, and thereafter, with the key forming chamber. The sleeve may be filled with mortar to form a shear key and connect the upper and lower reinforcing bars.

Further, the invention according to claim 3 is characterized in that a vertically oriented tubular steel material is used as the key reinforcing steel material.

[0010]

As described in claims 1 and 2, when the recesses for forming the keys are provided so as to face each other on the joint surfaces of the upper and lower precast concrete blocks, the upper and lower blocks can be superposed without trouble unlike the fitting of the concavities and convexities. It can be performed.

When the shear key is formed later by filling the mortar with the key reinforcing steel material interposed in the key forming chamber in which the upper and lower key forming recesses are formed as described in claims 1 and 2, The shear key can be formed without any problem even if the circumferential position of the key forming recess is slightly displaced.

According to a second aspect of the present invention, a sleeve is provided in the precast concrete block so as to communicate with the downwardly facing concave portion for forming a key, and the reinforcing bars of the upper and lower precast concrete blocks are inserted into the sleeve. When mortar is filled in the forming chamber, the upper and lower reinforcing bars can be connected together and the shear key can be formed together.

Further, as in claim 3, by using the tubular steel material as the key reinforcing steel material, the inter-block connecting bar can be easily inserted.

[0014]

1 to 3 show one embodiment of the present invention. In this embodiment, the key forming recesses 5 and 6 are provided in advance so as to face each other on the upper surface of the lower precast concrete block 2 and the lower surface of the upper precast concrete block 2 which is overlaid thereon. .

Further, in each precast concrete block 2, a metal sleeve 7 made of iron or the like is preliminarily built in by making the lower end communicate with the downward key forming concave portion 6. Further, the lower portion 8a of the inter-block connecting bar 8 which is inserted into the precast concrete block 2 having the sleeve 7 built thereinto is previously inserted into the sleeve 7. On the other hand, from the upwardly facing key forming concave portion 5 of the precast concrete block 2 located therebelow, the upper portion 8b of the interblock connecting bar 8 inserted into the lower precast concrete block 2 is inserted into the sleeve 7 thereabove. Make it possible to project in advance.

When building a well, the upper precast concrete block 2 and the key forming recesses 5 and 6 are opposed to each other on the lower precast concrete block 2, and the inter-block connecting bar 8 on the lower side is formed. The upper part 8b of the above is inserted into the upper sleeve 7 so as to be superposed.

A key forming chamber 9 is formed by facing both of the key forming recesses 5 and 6. When stacking the upper and lower blocks 2 in this way, as shown in FIGS. 2 and 3, the key-reinforcing steel material 10 is put in the upward key-forming concave portion 5 and the key-forming chamber 9 is spread over the upper and lower blocks. In this state, the key reinforcing steel material 10 is incorporated.

As the key reinforcing steel material 10, as shown in FIGS. 2 and 3, a plurality of tubular steel materials 10a and 10b are arranged in a substantially concentric arrangement.
.. are connected by a connecting member 10c. The outermost tubular net material 10a has a long lower side, and the mortar inflow / outflow hole 1
0d is opened. In addition, as shown in FIG. 4, a rebar formed in a spiral shape may be used. Further, the upper and lower blocks 2 are overlapped with each other with an adhesive 11 interposed therebetween.

In this state, the injection hole 12 communicating with the key forming concave portion 5 of the lower precast concrete block 2 from the inner periphery of the block 2 and the sleeve 7 in the upper precast concrete block 2 are connected to the block 2. The key forming chamber 9 is formed by utilizing the discharge hole 13 communicating from the inner circumference.
And high-strength high-strength mortar are injected into the sleeve 7 and the key forming chamber 9 to form a shear key with the injection mortar and the key reinforcing steel material 10. The sleeve 7 connects the upper and lower block connecting bars 8 and 8 with the mortar. Are connected. Upper and lower blocks 2
Since they are connected by the adhesive 11, the adhesive 11 can prevent the mortar from leaking from the key forming chamber 9.

When each of the tubular members forming the well is large, a plurality of arc-shaped segments may be combined to form a tubular shape, but the same can be done in this case.

In the above-described embodiment, the sleeve 7 is provided in the place where the shear key is formed, and the inter-block connecting bars 8a and 8b are provided.
However, the sleeve 7 may be omitted if the inter-block connecting muscles 8a and 8b are not provided.
Further, in this case, the discharge hole 13 is provided so as to communicate with the key forming recess 6.

[0022]

As described above, according to the present invention, since the key forming recesses are provided so as to face each other on the joint surfaces of the upper and lower precast concrete blocks, unlike the fitting of the concavities and convexities, the upper and lower blocks are superposed. Will be easier.

Further, since the shear key is formed later by filling the mortar with the key-reinforcing steel material interposed in the key forming chamber formed by the upper and lower key forming recesses, the upper and lower key forming recesses are Even if the position in the circumferential direction is slightly displaced, the shear key can be formed without any trouble, and since the high-strength material can be used only for the shear key, the shear key with high strength can be formed at low cost.

Further, a sleeve is provided in the precast concrete block so as to communicate with the downward key-forming recess, and the inter-block connecting bars of the upper and lower precast concrete blocks are inserted into the sleeve, and inside the sleeve and the key-forming chamber. Since the mortar is filled, the shear key can be formed and the upper and lower rebars can be connected together.

Further, by using the cylindrical steel material as the key reinforcing steel material in the up and down direction, the inter-block connecting bar can be easily inserted.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a part of an example of a tubular structure formed by a method of the present invention in a partially cutaway manner.

FIG. 2 is an enlarged cross-sectional view of a portion of a shear key forming chamber and a sleeve in the tubular structure of the present embodiment.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a partial vertical cross-sectional view of another embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a conventional tubular structure.

FIG. 6 is an enlarged vertical sectional view of a connecting portion of upper and lower blocks in a conventional tubular structure.

[Explanation of symbols]

 1 Ground 2 Precast concrete block 3 Shearing key 4 Recessed 5, 6 Recessed for key formation 7 Sleeve 8 Interlocking block 9 Key forming room 10 Key reinforcement steel 11 Adhesive 12 Injection hole 13 Discharge hole

Claims (3)

[Claims] 1. A method for constructing a tubular structure, comprising stacking tubular precast concrete blocks and fixing the upper and lower precast concrete blocks by a joining method having a shear key function, wherein the upper and lower precast concrete blocks are: The key forming recesses facing each other are provided in advance on the joining surface, and the upper and lower precast concrete blocks are stacked by vertically interposing a key reinforcing steel material in the key forming chamber formed by the upper and lower key forming recesses. Thereafter, a method for constructing a tubular structure is characterized in that the key forming chamber is filled with mortar to form a shear key. 2. A tubular structure in which tubular precast concrete blocks are stacked, the upper and lower precast concrete blocks are fixed by a joining method having a function with a shear key, and the upper and lower precast concrete blocks are connected by a reinforcing bar. In the construction method of the object, the upper and lower precast concrete blocks are provided with key forming recesses facing each other in advance on their joint surfaces, and the upper precast concrete block is formed with a key forming lower surface. The lower end was made to communicate with the recess and the sleeve was built in beforehand, and the upper end of the lower inter-block connecting bar inserted through the sleeve into the precast concrete block below and the inside of the precast concrete block above Insert the lower end of the upper block connecting muscle. In addition, the upper and lower precast concrete blocks are stacked by vertically interposing a key reinforcing steel material in the key forming chamber formed by the upper and lower key forming recesses, and then mortar is placed in the key forming chamber and the sleeve. A method for constructing a tubular structure, which comprises filling and forming a shear key and connecting the upper and lower reinforcing bars. 3. The method for constructing a tubular structure according to claim 1, wherein a tubular steel material oriented up and down is used as the key reinforcing steel material.