JPH04293830A - Constructing method for box culvert and block - Google Patents

Abstract

PURPOSE:To provide a constructing method which has good handling and execution of works, and free size though the method is of precast and a block used for the constructing method. CONSTITUTION:Side plate parts, a bottom plate part protruded from the side parts, and two one-side-opened square-shaped concrete blocks composing part of a top plate part are arranged by facing each other. Reinforcing steel is inserted and assembled between the concrete blocks or steel products are inserted into and penetrated through a plurality of holes passing the outer surfaces of the side plates from cross sectional end parts. The result performs hypertension unitary construction. Concrete is then piled and filled to form the bottom plate part and the top plate part. This constructing method uses a block comprising the side plate parts 2, a bottom plate connection part 1 protruded from the side plate parts, and a top plate connection part 3 and in which the bottom plate connection part 1 or the top plate connection part 3 is provided with arrangement of reinforcement holes passing to the protruded braces 4 at the cross sectional end parts or the outer surfaces of the side plate parts from the cross sectional end parts.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box culvert construction method for constructing passages and culverts using pre-fabricated concrete blocks, and a half precast type block used therein.

0002

[Prior Art] As shown in Fig. 4, the conventional method for constructing a box culvert is as follows: - Side slabs 12 are assembled on both sides of a bottom slab 11 installed on foundation concrete 10, and the top is placed on top of the bottom slab 11. Put version 13 on it and integrate it,
■As shown in Fig. 5, a lower block 14 is installed on the foundation concrete 10, which includes a bottom plate 11 and side plates 12, 12 of approximately half the height on both sides thereof, which are integrally provided at the time of manufacturing, and placed on top of the bottom block 14, which has approximately the same shape. The upper block 15 can be installed in the opposite direction, or, as shown in JP-A-51-79950, U-shaped or E-shaped precast concrete blocks can be installed facing each other and connected at the butt ends. Construction methods such as:

[0003] The construction method shown in ■ has the advantage that the side wall height can be adjusted, so the size can be chosen freely, and one part is light, making it easy to transport, but it requires a large number of parts. Therefore, it is time-consuming to install, and there are many parts that need to be water-stopped. The construction method shown in ■ is the most commonly used construction method for large and medium-sized box culverts.It has a small number of divisions, is easy to construct, and can be relatively easily adapted to the required size by adjusting the side wall height. Although it has some characteristics, it has disadvantages such as transportation restrictions depending on its height and relatively heavy weight, which requires large heavy machinery (crane). Although the construction method shown in (2) has the advantage of having a small number of divisions and good workability, it also has the disadvantage that the block becomes larger and cannot be changed to the required diameter size.

0004

[Problems to be Solved by the Invention] When constructing a box culvert, the present invention is easy to transport even though it is precast, it is possible to use relatively small heavy machinery, and the diameter can be changed freely, making it easy to handle and construct. This is an attempt to provide a method for constructing a box culvert of any size and the blocks used for it.

[0005]

[Means for Solving the Problems] As a result of various studies on the above problems, we developed the following two methods for constructing box culverts. In other words, ■ two U-shaped concrete blocks constituting a part of the side slab and the bottom slab and top slab that protrude from the side slab, respectively, with the protruding reinforcement sides protruding from the upper and lower cross-sectional ends inward. A box culvert construction method characterized by arranging the boxes facing each other, inserting and assembling reinforcing bars between them, and then pouring and filling concrete to form a bottom slab and a top slab. Two U-shaped split box culverts are lined up facing each other with their cross-sectional ends and inner sides facing each other, and steel material is inserted into the multiple holes that penetrate from the cross-sectional ends to the outer surface of the side slabs provided in the top or bottom slabs. This is a box culvert construction method characterized by inserting a box culvert and integrating it with tension.

The box culvert construction block used to carry out these methods consists of a side slab portion 2, a bottom slab connecting portion 1 and a top slab connecting portion 3 protruding from the side slab portion. The plate connecting portion 3 has a structure in which protruding reinforcements 4 at the end of the cross section or reinforcement holes 5 penetrating from the end of the cross section to the outer surface of the side plate are provided. When assembling the reinforcing bars, the protruding bars and the reinforcing bars may be connected by any other suitable means in addition to the commonly used means of joining the bars together by wire or welding.

[0007]

[Operation] This box culvert construction method can be called the block half precast box culvert construction method, in which the left and right side walls, corbels, top, and part of the bottom slab are integrated, and side slabs are lined up at equal intervals on both sides. By placing reinforcing bars in the middle and pouring cast-in-place concrete, a composite structure is created.

[0008] The block used for this is a precast product in which the side wall, haunch, top, and part of the bottom plate are integrated, and reinforcing bars protrude from the cross section of the top and bottom plate, or there are reinforcing bars protruding from the cross-sectional end to the outer surface of the side plate. A structure having a top plate connecting part, such as a structure with a plurality of penetrating holes, is arranged in two rows in parallel at a predetermined interval,
By building reinforcing bars between them and filling them with cast-in-place concrete, it is possible to create an integrated box culvert with any diameter.

Generally, the larger the diameter of the box culvert, the higher the cost of the precast box culvert product, but in the case of the present invention, even if the box culvert has a larger diameter, both the left and right precast blocks are large. This is advantageous in terms of transportation, handling, workability, etc. This makes it possible to save labor in large box culverts cast on site, which has not been possible with precast products until now.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention, and is a perspective view of the box culvert when it is constructed. In this example,
U-shaped box culvert construction blocks protrude from the side slab portion 2 and the bottom slab connecting portion 1 and top slab connecting portion 3
It consists of There is a protruding line 4 at the end of the bottom plate connecting part 1 and the top plate connecting part 2. These two concrete blocks are arranged on the foundation concrete 10 with the protruding reinforcement sides protruding from the upper and lower cross-sectional ends facing each other, and the main reinforcing bars for connection are inserted and assembled between them, and after the framework is assembled, concrete is poured on site. The bottom plate part and the top plate part are formed by filling the plate.

FIGS. 2(a) to 2(d) show the construction step by step. (a) shows how the box culvert construction blocks of the present invention are installed on the foundation concrete 10 with the protruding reinforcing bars 4 side facing inward and facing each other so as to have the designed diameter. In (b), after reinforcing bars 6 are arranged in the bottom slab portion, concrete is poured to form the bottom slab 7. Next, (c) shows how the formwork 8 is supported and assembled between the top plate connecting parts 3 and 3 by the supports 11. After that, as shown in (d), reinforcing is placed on the top slab, concrete is poured, and the top slab is formed to complete the work.

[0012] In the above embodiment, an example was shown in which the protruding striations 4 were provided at the ends of the bottom plate connecting part 1 and the top plate connecting part 2, but the box culvert construction block of the present invention has protruding lines 4 at the bottom plate connecting part 1 and the top plate connecting part 2. It is also possible to provide a structure in which reinforcing holes 5 penetrating from the cross-sectional end to the outer surface of the side plate are connected with tensioning steel members 9. An example thereof is shown in FIG. Reinforcement is placed between the box culvert construction blocks of the present invention, which are installed facing each other, with tension steel 9 inserted through the reinforcement holes 5, and a formwork is constructed in the same manner as in the above embodiment, and then concrete is poured. After the top plate 12 is formed, it is properly tightened with a nut screwed into the threaded part at the end to create a tensioned state, so that the required strength can be maintained even if the thickness of the top plate and bottom plate parts is reduced. be. Construction using this box culvert construction block also differs in the reinforcement arrangement, but it is almost the same as shown in Figure 2 (a).
A box culvert can be constructed through the construction steps shown in ) to (d).

[0013]

Effects of the Invention The present invention achieves many effects as described below by virtue of the structure and operation described above. ■The troublesome side walls and corbels are constructed with precast products, so construction is quick. ■Reinforcement processing can be done by simply tying straight bars or mesh together, making construction quick and economical. ■The only formwork required is the flat top plate, making it simple and economical. ■Large boxes that cannot be transported can now be constructed using the composite precast construction method. ■Economical as it can be constructed using relatively small heavy machinery (crane). ■
The top slab and bottom slab are integrated vertically due to on-site casting,
This compensates for the split structure, which is a drawback of precast. ■The larger the size, the higher the construction cost for precast products than for cast-in-place boxes, but combining them with cast-in-place boxes reduces the overall construction cost. ■Easy to completely stop water. ■The foundation ground and bottomed concrete are in close contact, and evenly distributed reaction force can be expected.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a box culvert according to a first embodiment of the present invention.

FIG. 2 is a side view showing the state of construction.

FIG. 3 is a perspective view of a box culvert according to a second embodiment of the present invention.

FIG. 4 is a side view showing the state of conventional construction.

FIG. 5 is a side view showing the state of conventional construction.

[Explanation of symbols]

1 Bottom plate connection part 2 Side printing section 3 Top plate connection part 4. Prominent muscles 5 Reinforcement hole 6 Rebar 7 Bottom plate 9 Steel material for tensioning

Claims (3)

[Claims] Claim 1: Two U-shaped concrete blocks constituting a part of the side slab and the bottom slab and the top slab that protrude from the side slab, respectively, on the protruding reinforcement sides that protrude from the upper and lower cross-sectional ends of each other. A box culvert construction method characterized by arranging the culverts facing each other on the inside, inserting reinforcing bars between them, assembling them, and then pouring and filling concrete to form a bottom slab and a top slab. Claim 2: Two U-shaped split box culverts constituting part or all of the box culverts are lined up facing each other with their cross-sectional ends facing inside, and the cross-sectional ends provided on the top or bottom slabs are placed side by side. A box culvert construction method characterized by inserting steel materials into multiple holes penetrating the outer surface of the slab and integrating them under tension. 3. Consisting of a side plate portion 2, a bottom plate connecting portion 1 and a top plate connecting portion 3 protruding from the side plate portion, the bottom plate connecting portion or the top plate connecting portion has a protruding line 4 at the cross-sectional end or a cross-sectional end. A block for constructing a box culvert, which is provided with reinforcement holes 5 penetrating from the outer surface of the side slab.