JPH0432191B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for constructing a cylindrical prefabricated tank such as a concentric cylindrical sewage treatment tank in a sewage treatment facility installed for treating sewage. .

[Prior art and problems to be solved by this invention]

Conventionally, this type of sewage treatment tank has been constructed entirely on-site, and the entire construction work, including formwork installation, assembly, and demolding, is complicated, resulting in poor construction efficiency and difficulty in constructing the tank. The problem was that it was expensive.

Therefore, in order to complete sewage treatment facilities, a sewage treatment tank that can be easily and inexpensively constructed has been desired.

This invention was developed in view of the above-mentioned circumstances, and its purpose is to provide a method of constructing a cylindrical prefabricated tank to serve as a sewage treatment tank in a short time and at low cost through simple assembly work.

[Means for solving problems]

This invention is a method for constructing a cylindrical prefabricated tank on a foundation by connecting prefabricated blocks each having a shape in which a cylindrical tank is divided into a plurality of parts in the generatrix direction, and in which the upper and lower parts of each prefab block are connected to each other. A connecting prestressed steel material is inserted into a through hole formed inside so as to communicate in the circumferential direction, and tensioned, and adjacent prefabricated blocks are connected to form a cylindrical tank, and a predetermined portion of the plurality of prefabricated blocks is The PC steel material for prestressing is inserted into the insertion holes formed above and below in the shape of fixing ribs in the generatrix direction that protrude from the outer surface of each block in the generatrix direction, and the prestressing PC steel material is wound and tensioned around the outer circumference of the cylindrical prefabricated block to apply prestressing. This is an attempt to solve the above-mentioned problem by attaching the parts to each other and joining them together.

〔Example〕

The present invention will be explained below with reference to illustrative embodiments.

Note that this embodiment is an example of a concentric cylindrical prefabricated tank using the cylindrical prefabricated tank according to the present invention as an outer wall.

The concentric cylindrical sewage treatment tank 1, which is a cylindrical prefabricated tank, has an inner sedimentation tank part 3 surrounded by a cylindrical inner wall 2 formed at the center, and a cylindrical sedimentation tank part 3 formed on the outer periphery of this inner sedimentation tank part 3. It consists of an outer aeration tank section 5 surrounded by an outer wall 4.

The inner wall 2 and the outer wall 4 are cylindrically joined by a prefabricated inner wall block 2a having a shape obtained by dividing a cylindrical tank in the generatrix direction, and an outer wall prefabricated block 7 having rib portions 7a formed at the upper and lower ends of the cylinder. It's getting warmer. (See Figures 1 and 2) When constructing the treatment tank 1 having such a configuration, first, a plurality of prefabricated outer wall blocks 7 are assembled.
The prefabricated block 7 is assembled in a cylindrical shape on the foundation 8 by being tension-connected by the connecting PC steel material 6, and is integrally joined by applying prestress in the circumferential direction on the outer peripheral surface of the prefabricated block 7 assembled in the cylindrical shape to form the outer wall 4. form. (See FIGS. 3 to 8) Prestress on the outer circumferential surface is achieved by forming fixing rib strips 7b in the generatrix direction between the upper and lower rib portions 7 for every predetermined number of the plurality of prefabricated blocks 7,
This is done by inserting the prestressing PC steel material 9 into a plurality of insertion holes provided in the rib strip 7, and winding it around the outer peripheral surface of the prefabricated block 7, which is joined into a cylindrical shape, and fixing the prestressing steel material 9 under tension. .

In addition, in order to apply prestress to the outer peripheral surface of the outer wall 4 formed by the plurality of prefabricated blocks 7 and integrate them, the circumferential length is approximately 1/2 (approximately 1/3 circumferential length is also acceptable). 1/2 of PC steel material 9 (3 pieces)
(1/3) An anchor that is wound around the entire length of the outer circumferential surface of the outer wall 4 for each outer circumferential surface, and is formed on the prefabricated block 7 for the outer wall at the end contact position of these two (three) PC steel materials 9. This is done by grip-fixing the ends of each PC steel material 9 to the retaining rib strip 7b. Note that the grip fixing positions are fixed at different angles of 60° (90°) for each stage. (See Figures 8, 10, and 11) Next, the bottom plate 1 is placed on the internal foundation 8 surrounded by the outer wall 4.
Pour concrete for forming 0. At this time, the lower end of each prefabricated outer wall block 7 and the bottom plate 10 are connected by anchor members 11.
(See Figures 3 and 5) Next, a plurality of prefabricated inner wall blocks 2a are formed on the bottom plate 10 in a circular shape with the same center as the outer wall 4, and connected to the bottom plate 10 by anchor bars 13 using the grooves 12. The inner wall 2 is formed by assembling the prefabricated block 2a into a cylindrical shape, and connecting and joining the inner and outer parts using a connecting fitting 14 provided on the connection surface of the prefabricated block 2a and bolts and nuts (not shown). (See Figures 12 and 13.) Meanwhile, a joint material is injected into the joint surfaces of each prefabricated block 4a for external walls, and the joint surfaces of each prefab block 4a for external walls, the joint surfaces of each prefab block 2a for internal walls, and the outer wall. The construction of the processing tank 1 is completed by filling the corners of the prefabricated block 4a for the inner wall and the bottom plate 11 with sealing material, and filling the inner and outer corners of the prefabricated block 2a for the inner wall, the bottom plate 11, and the inner and outer corners with mortar. (See FIG. 14) The anchor members and anchor bars used in this embodiment are made of iron-plated round steel, stainless steel round steel, or the like.

〔Effect of the invention〕

By tension-fixing the prestressing PC steel material wound around the outer circumferential surface of each prefabricated block using fixing rib strips, construction can be performed easily and efficiently, and a strong cylindrical prefabricated tank can be provided.

In other words, the prestressing prestressing prestressing steel material can be used to firmly and integrally join the blocks, and the prestressing prestressing prestressing material can be easily applied by wrapping the prestressing prestressing prestressing steel material around the outer circumferential surface of each prefabricated block instead of wrapping it around the inside and fixing it under tension on the fixing rib part. Therefore, it is possible to provide a circular prefabricated tank that is easy to construct and strong.

For these reasons, the method for constructing a cylindrical prefabricated tank of the present invention can provide a concentric cylindrical sewage treatment tank that is easy to construct, efficient, and strong.

Therefore, a treatment tank for a sewage treatment facility can be constructed at low cost.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing a treatment tank constructed by the method of the present invention, FIG. 2 is a plan view thereof,
Figures 3 to 8 are process diagrams showing the state of construction of the outer wall;
Fig. 9 is an enlarged view of part A in Fig. 8, Figs. 10 and 11 are cross-sectional views showing the tension fixing state of the prestressing PC steel material, and Figs. 12 and 13 are process steps showing the construction state of the inner wall. 14 are cross-sectional views showing the processing tank after construction is completed. 1... Concentric cylindrical sewage treatment tank, 2... Inner wall, 2
a... Prefabricated block for inner wall, 3... Inner sedimentation tank part, 4... Outer wall, 5... Outer aeration tank part, 6... PC steel material for connection, 7... Prefabricated block for outer wall, 7a... Upper and lower rib portion, 7b
... Fixing rib strip, 8 ... Foundation, 9 ... PC steel material for prestressing, 10 ... Bottom plate, 11 ... Anchor member, 12 ... Groove, 13 ... Anchor reinforcement, 14 ...
...Connection fittings.

Claims (1)

[Scope of Claims] 1. A method of constructing a cylindrical prefabricated tank on a foundation by connecting prefabricated blocks each having a shape in which a cylindrical tank is divided into a plurality of pieces in the generatrix direction, comprising the steps of: Connecting prefabricated steel materials are inserted into through holes formed in the upper and lower parts so as to communicate in the circumferential direction, and tensioned to connect adjacent prefabricated blocks to form a cylindrical tank. The PC steel material for prestressing is inserted into the insertion holes formed in the upper and lower parts of the fixing rib strips in the generatrix direction that are formed protruding from the outer surface of the block every predetermined number of pieces, and the prestressing PC steel material is wound around the outer circumference of the cylindrical prefabricated block to create prestressing. A method for constructing a cylindrical prefabricated tank, characterized in that it is integrally joined by giving.