JPH084021A - Method of constructing cylindrical structure - Google Patents

Abstract

PURPOSE:To construct an underground structure and a ground structure as a united pressedressed reinforced concrete(PRC) structure without providing a pier, etc., with a footing, using a precast block. CONSTITUTION:Cylindrical precast blocks 5 provided with reinforcement insertion holes and PC steel bar insertion holes are stacked in order on a base block 2, and those are coupled with one another by PC steel bars 7, and the blocks 5 are press-fit in ground. Next, the stacking of the blocks 6 on ground part is repeated to form a ground structure, and it is passed into the block and reinforcements 8 are inserted from above, and those are fixed by grouting, thus a cylindrical structure consisting of PRC structure is constructed.

Description

Detailed Description of the Invention

[0001]

The present invention relates to PRC (Prestressed)
Reinforced Concrete: A method of constructing a tubular structure for constructing a substructure of a prestressed reinforced concrete structure. For example, regarding the method of constructing a substructure such as a bridge pier or the foundation of a structure, in more detail, a prestressed reinforced concrete (PRC) structure using a tubular precast concrete block (hereinafter referred to as a precast block) The present invention relates to a construction method for constructing a structure integrally.

[0002]

2. Description of the Related Art For bridge piers and the like, foundation piles, foundations (footings), etc. are constructed, columnar frames are constructed on them by cast-in-place concrete, or precast blocks are piled on the footings. Was constructed by the technique of constructing foundation piles by sinking wells and building footings on them.

In the case of constructing such a structure by stacking precast blocks, since the reinforcing bars embedded in each block are stacked by using joints, the block manufacturing accuracy is improved. There was a problem in maintenance, joining work, etc. Further, since there is a joint on the joint surface, it is necessary to provide a shear key or the like for shearing the joint. On the other hand, the technology to insert the reinforcing bar into the precast block without pre-embedding the reinforcing bar in advance is "Civil engineering construction Vol. It has been reported. In this technique, the connecting position of the reinforcing bar is concentrated by using a special block.

On the other hand, a PC using a precast block
When constructing a substructure of a (prestressed concrete) structure, if the joint surface is subjected to full prestress and the joint surface of the precast block is uneven, there is a problem that a large local stress is generated in the convex portion and the joint surface is damaged. Requires a high level of flatness and must be applied, for example, with a mirror finish or a matchcast precast block must be manufactured.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a precast block is used to form an integrated prestressed reinforced concrete (PRC) structure for an underground structure and an aboveground structure without separately providing footing, and a pier or the like can be constructed in a short period of time. It is intended to provide a building method for building. The more specific objects of the present invention are as follows.

(1) Construction is continuously performed without dividing the process of the underground foundation portion and the above-mentioned columnar portion portion. (2) The structure of the block joint surface does not require high precision such as mirror finishing. (3) Concentration of reinforcing bar connection positions is eliminated without providing a reinforcing bar joint block or the like.

[0007]

In order to achieve the above object, the present invention comprises the following technical means. That is, the underground press-fitting blade opening is attached to the reference block, and the reinforcing bar insertion hole and P
Cylindrical precast blocks provided with C steel rod insertion holes are sequentially stacked on the reference block and sequentially connected with PC steel rods,
Pressing the block stack into the ground while repeating the earth removal in the block and the stacking of the tubular precast block, sinking into the ground until the blade edge reaches the support base, then,
A cylinder characterized by repeatedly stacking cylindrical precast blocks to form a ground structure, and inserting a reinforcing bar from above through a reinforcing bar insertion hole of the stacked blocks to fix a grouting structure to construct a PRC structure. It is a method of constructing a structure. In this case, it is preferable that the through-bars are provided at joint positions at different levels from each other.In addition, when the grouting liquid is inserted into the grouting liquid after the grouting liquid is injected into the grouting liquid when the grouting liquid is inserted and fixed by grouting. Pickling is preferable.

[0008]

The present invention has the following effects due to the above configuration. (A) It is possible to continuously and integrally construct the foundation portion and the columnar portion on the ground. (B) The PRC structure prevents the precast block from being excessively prestressed. Therefore, the precast block does not require high flatness of the joint surface, and does not require mirror finishing treatment or match casting, and the manufacturing process of the precast block can be simplified.

(C) Since all the blocks are stacked and the main structural rebar is post-inserted, it is not necessary to use a special connection block. It can be easily inserted by previously forming a reinforcing bar insertion hole having a sufficient diameter. Furthermore, since there is no coupler on the joint surface between the precast blocks and the rebar itself traverses, it is not necessary to take measures such as providing a shear key on the joint surface of the precast blocks, unlike the RC precast block.

(D) Adhesion between the inserted rebar and the block is carried out with a grout. (E) The grout injection is performed before the rebar is inserted, and the rebar is submerged in the grout solution, so that no void is generated between the insertion hole and the rebar. In this case, the liquid volume of the pre-injection grout is determined from the total volume of the insertion hole and the volume of the inserted rebar.

[0011]

EXAMPLE FIG. 1 shows a pier of an example. In the ground below the ground 2, a cylindrical precast block 5 is stacked above the reference block 3 to which the press-fitting blade mouth 4 is attached,
Further, the same tubular precast block 6 is stacked on the ground part, and these blocks 5 and 6 are connected by a PC steel rod 7, and a reinforcing bar 8 is inserted and integrated,
It forms an RC structure. A superstructure 9, for example a bridge girder, is installed on its top. A plan view of the tubular precast block that constitutes this pier is shown in FIG. In the blocks 5 and 6, the PC steel rod insertion hole 11 and the reinforcing bar insertion hole 1
2 are provided. Although FIG. 2 shows a block having a rectangular cross section, the cross sectional shape is arbitrary in the present invention. A circular, trapezoidal, polygonal, or any other cross-section block can be used as well.

The specifications of the pier of the embodiment are as follows. Underground length: 25 m Aboveground length: 32 m Cross-sectional dimension: 6 m x 4 m x Member thickness 0.6 m Block height dimension: 2 m Reinforcing bar: φ35 mm x 148 (insertion hole φ70 m
m) Assembled PC steel rod: φ32 mm x 24 (insertion hole φ70 m
m) Block weight: about 50 tons The pier of the example was constructed by the method of the present invention. The construction procedure will be described with reference to FIGS.

(1) The ground 2 at the construction position is surveyed and leveled, and an earth anchor 21 for producing a press-fit reaction force is constructed. (2) Install the steel press-fitting blade mouth 4 at the block press-fitting position. (3) Place the reference block 3 on the steel blade 4 and insert the PC steel rod 7 to fix the steel blade 4 tightly.

(4) A resin-based adhesive is applied to the joint surface of the tubular precast block 5, the blocks are hung by a crane 31, and the assembled PC steel rods 7 are stacked as a guide to stack the tubular precast blocks in four stages. Cod PC steel rod 7
And grout. (5) The loading beam 24 is placed on the upper part of the block, and the block is sunk into the ground by the jack 25 from the reaction beam 23 connected to the earth anchor 21. Carefully jack on the ground anchor while checking the horizontal and vertical directions with the level and transit. At the same time, the excavator 32 such as a bucket hammer excavates and discharges the earth and sand inside the block to settle into the ground.

(6) When the four stages of the cylindrical precast block are completely sunk, the reaction beam 23, the jack 25, and the loading beam 24 are removed, and the PC steel rod 7 for assembling the next block is tightened in the lower block. The end PC steel rod 7 is connected to the head using a coupler. (7) After that, the steps (4) to (6) are repeated twice to construct the underground portion 25m.

(8) When the underground portion is completed, earth and sand are put into the block to backfill it. (9) Connect the PC steel rods 7 that assemble the blocks that construct the above-ground portion. (10) Apply a resin adhesive to the block joint surface, hang the block with the erection work scaffold 35 attached by the crane 31, stack using the assembled PC steel rods 7 as guides, and stack the tubular precast blocks in four stages PC steel rod 7
And grout.

The steps (11) and (10) are repeated three times to construct the ground columnar section 32m. (12) Install work scaffolds around the top block. (13) Inject a super delayed coagulable grout solution into the reinforcing bar insertion hole. The grout solution is injected by calculating the volume of the insertion hole and the volume of the reinforcing bar. Determine the amount so that it will overflow slightly from the top when the rebar insertion is completed.

(14) Reinforcing bars are assembled on the ground in a comb shape, and are suspended by a crane using a suspending tool 33 to be sunk into an insertion hole into which grout liquid is injected. Reinforcing bars should be connected at different heights. At this time, if the reinforcing bars over the entire length cannot be inserted at one time, a temporary receiving jig is installed on the top of the structure to enable the split insertion. Also in this case, make a plan so that connection positions are not concentrated.

(15) Due to the strength development of the grout, the block body and the reinforcing bar are attached and integrated. In the example, the tubular structure in which the underground and above-ground portions were integrated could be constructed in a short period of time without dividing the work in the middle. In addition, the joining surface of the precast block does not need to be mirror-finished, the manufacturing process of the precast block is simple, there are no weak points in the joint of the precast block, and the construction of an excellent tubular structure is safe, inexpensive, and in a short construction period. Can be installed.

[0020]

According to the method for constructing the tubular structure of the present invention, the manufacturing accuracy of the joint surface of the precast block needs to be exceptional because the main structural rebar is post-inserted and the PRC structure is adopted. Since there is no need for match casting or mirror finishing, the precast block can be manufactured in any order and with no precision. In addition, the underground foundation part and the above-ground columnar part are continuously integrated, there is no division of the construction process, the construction efficiency is improved, and the precast block can be manufactured in advance, which increases the degree of freedom in the construction period and wastes. Therefore, it is possible to efficiently set the construction period, and it is possible to construct a high quality cylindrical structure safely, efficiently, and in a short construction period.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a tubular structure according to an embodiment of the present invention.

FIG. 2 is a plan view of a tubular precast block.

FIG. 3 is a process drawing of a construction process of an example.

FIG. 4 is a process diagram of a construction process of an example.

FIG. 5 is a process drawing of the construction process of the example.

FIG. 6 is a process drawing of the construction process of the example.

FIG. 7 is a process drawing of the construction process of the example.

[Explanation of symbols]

 1 Tubular Structure 2 Ground 3 Reference Block 4 Blade 5, 6 Precast Block 7 PC Steel Bar 8 Reinforcing Bar 9 Upper Structure 11 PC Steel Bar Through Hole 12 Reinforcing Bar Through Hole 21 Earth Anchor 23 Reaction Beam 24 Loading Beam 25 Jack 31 Crane 32 Excavator 33 Lifting tool 34 Coupler 35 Scaffold

Claims (3)

[Claims] 1. An underground press-fitting blade opening is attached to a reference block,
A cylindrical precast block provided with a reinforcing bar insertion hole and a PC steel rod insertion hole is sequentially stacked on the reference block to form a PC.
Sequentially connected with steel bars, press the block stack into the ground while repeating the soil discharge in the block and the stacking of the cylindrical precast block, sinking into the ground until the blade edge reaches the support base, Then, the stacking of the cylindrical precast blocks is repeated to form a ground structure, and the reinforcing bars are inserted through the reinforcing bar insertion holes of the stacked blocks from above and fixed by grouting to construct a PRC structure. A method for constructing a tubular structure. 2. The method for constructing a tubular structure according to claim 1, wherein the through bars are provided at joint positions at different levels. 3. The tubular shape according to claim 1 or 2, wherein, when the rebar is inserted and fixed by grouting, the grout solution is injected into the rebar insertion hole, and then the rebar is immersed in the grout solution. How to build a structure.