JP2002138561A - Structure and method for construction of box culvert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an obstruction to the traveling of a vehicle and labor for the control of a road by dispensing with smoothing by virtue of the elimination of a step between a temporary lining and a peripheral road surface. SOLUTION: The ground inside an earth retaining wall 2, which is created in the ground 1, is excavated to a prescribed depth, and a bracket 31 is mounted near the upper end of the wall 2. A precast concrete slab, constituting an upper slab 30D of a box culvert 30, is installed by being supported on the bracket 31. The precast concrete lab 30D is used as a strut and the temporary lining. The inside ground of the wall 2 on the lower side of the slab 30 is excavated in order to undergo leveling work. The base 30A and side walls 30B and 30C of the box culvert 30 are constructed in an excavated space and coupled to the slab 30D for the purpose of construction the box culvert 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a box culvert construction structure and a construction method.

[0002]

2. Description of the Related Art Conventionally, a box culvert provided under a road is constructed as follows. This will be described below with reference to FIG. 3 showing a cross section of the structure after the box culvert construction in the construction completion stage and FIGS. 4 (a) to (d) showing the outline of the construction process.

[0003] Box culvert 1 at an uncovered height
When constructing 2, the soil retaining wall 2 is first formed on the ground 1 as shown in FIG. 4A, and the intermediate pile 3 is set up as necessary. At this time, the upper end of the retaining wall 2 and the upper end of the intermediate pile 3 are made to protrude from the ground surface in order to attach a cutting beam or a temporary lining later.

[0004] Next, as shown in FIG. 4 (b), a first-stage cutting beam 6 is installed on the upper side of the ground 1 to support the belly 5 supporting the retaining wall 2. Also, a bracket 7 is attached to the upper end of the earth retaining wall 2 or the intermediate pile 3 protruding from the ground 1, a support 8 is installed by supporting the bracket 7, and a temporary lining (here, Then, a temporary lining plate) 10 is installed. At this stage, since the temporary lining 10 protrudes by 1 m or more from the peripheral road surface, the sliding 15 is provided to eliminate a step between the temporary lining 10 and the peripheral road surface.

In this state, as shown in FIG. 4 (c), under the temporary lining 10, the ground 1 inside the retaining wall 2 is excavated and flooring is performed (the flooring portion is indicated by reference numeral 11). ).
Then, as shown in FIG. 4D, a reinforcing bar assembly (not shown) is performed in the excavated space, and the bottom slab 12A, the side wall 12B,
Box culvert 1 consisting of 12C and upper slab 12D
2 to obtain the structure of FIG.

[0006]

As described above, conventionally, when the box culvert 12 is constructed at an uncovered height, the temporary lining 10 becomes higher than the surrounding road surface. Sliding to eliminate the step between them 1
5 was needed. As a result, there have been problems such as hindrance in running the vehicle and troublesome turning of the road.

The present invention, in consideration of the above circumstances, can eliminate the step between the temporary lining and the surrounding road surface, and eliminates the need for rubbing, which may hinder the running of the vehicle or cause a problem on the road. It is an object of the present invention to provide a box culvert construction structure and a construction method capable of preventing problems such as troublesome turning operations and thereby reducing construction costs.

[0008]

The construction of the box culvert according to the first aspect of the present invention is characterized in that the upper slab of the box culvert is composed of a precast concrete slab which also serves as a cutting beam and a temporary lining when the box culvert is constructed. It is characterized by doing.

According to a second aspect of the present invention, there is provided a box culvert construction method wherein the upper slab of the box culvert is formed of a precast concrete slab, and the precast concrete slab is used as a cutting beam and a temporary lining. It is characterized by excavating the lower ground to construct a box culvert.

[0010] The invention of claim 3 is a more specific embodiment of the box culvert construction method according to claim 2, wherein the step of forming an earth retaining wall with respect to the ground and the step of forming the inner ground of the earth retaining wall by a predetermined method. Excavating only to the depth, attaching a bracket near the upper end of the retaining wall, taking support for the bracket,
Installing a precast concrete slab constituting the upper slab of the box culvert, and using the precast concrete slab as a girder supporting the retaining wall and a temporary lining to form a lower retaining wall on the lower side of the precast concrete slab. Excavating the inner ground and laying the floor, and constructing a box culvert by connecting the precast concrete slab to the bottom plate and side walls of the box culvert in the excavated space, I have.

According to a fourth aspect of the present invention, there is provided the box culvert construction method according to the third aspect, wherein the precast concrete slab constituting the upper slab of the box culvert and the side wall of the box culvert are connected by anchor bolts. And

According to a fifth aspect of the present invention, there is provided the box culvert construction method according to the third or fourth aspect, wherein a prestress is introduced into the precast concrete slab to integrate the precast concrete slab. It is characterized by.

According to a sixth aspect of the present invention, there is provided the box culvert construction method according to any one of the third to fifth aspects, wherein the bottom plate and the side wall of the box culvert are constructed.
It is characterized in that concrete is charged using holes provided in the precast concrete slab.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a structure after construction when the box culvert 30 is constructed at a height without soil cover, and FIGS. 2A to 2D sequentially show an outline of a construction process of the box culvert 30. It is sectional drawing.

The first point in the construction of the box culvert is that the upper slab 30D of the box culvert 30 is made of a precast concrete slab (hereinafter also denoted by the same reference numeral 30D as the upper slab). . Hereinafter, a standard construction procedure will be described with reference to FIG.

First, as shown in FIG. 2A, the earth retaining wall 2 is formed on the ground 1, and the intermediate pile 3 is set up as necessary. At this time, the retaining wall 2 is provided at a position where the construction space is not provided between the box culvert 30 to be constructed (the inside position as much as possible), and the support span of the precast concrete slab (upper slab) 30D to be installed later. Try to minimize. In parallel with the formation of the retaining wall 2, a precast concrete slab constituting the upper slab 30D is manufactured. And the ground 1 inside the retaining wall 2 to a depth where the precast concrete slab 30D can be set.
And the bracket 31 for receiving the precast concrete plate 30D is attached to the core material of the retaining wall 2.

Next, as shown in FIG.
1 and a precast concrete slab 30D is installed. This precast concrete slab 30D
Since it serves as both a temporary lining and a girder supporting the retaining wall 2, it is not necessary to provide other temporary linings and girders. Therefore, the height of the temporary lining can be set to be the same as the height of the peripheral road surface, and the need for sliding can be eliminated.

During or after the construction, if there is a concern about the influence of the deflection displacement of the precast concrete slab 30D due to the running of the vehicle, the precast concrete slab 30D may be used.
A prestress is introduced into D, so that a plurality of precast concrete slabs 30D are integrated and the strength is increased. Depending on the conditions, the introduction of prestress may be omitted.

In this state, as shown in FIG. 2 (c), the retaining wall 2 is located below the precast concrete slab 30D.
The ground 1 inside is excavated and flooring is performed (a flooring portion is indicated by reference numeral 11).

Then, as shown in FIG. 2D, a bottom plate 30A of the box culvert 30 is constructed in the excavated space, and a precast concrete plate 30D and a side wall 30D are formed.
After setting the anchor bolts 32 for connection to the side walls 30B and 30C and performing rebar assembly on the side walls 30B and 30C,
B, 30D, the bottom plate 30A, the side walls 30B, 30
C, a box culvert 30 composed of the upper slab 30D is obtained. It is to be noted that the concrete is charged at the time of constructing the bottom slab 30A and the side walls 30B and 30C by using the holes for concrete input provided in the precast concrete slab 30D. The precast concrete 30D has an insertion hole for the anchor bolt 32, an air vent hole, and the like.

With this construction, the sliding 15 (see FIGS. 3 and 4), which is conventionally required, is not required, so that the running of the vehicle is hindered and the turning of the road is troublesome. The problem such as losing does not occur. In addition, since there is no need to install a girder or a temporary lining, construction efficiency is increased and construction costs can be reduced. In addition, upper slab 3
Since 0D and the side walls 30B and 30C are connected by the anchor bolts 32, the resistance to the shearing force and the tensile force acting on the top of the side wall also increases.

[0022]

As described above, according to the first and second aspects of the present invention, the upper slab of the box culvert is made of a precast concrete slab, and the precast concrete slab is used to cut the beams and the temporary covering during construction. Since the work also serves as the work, the step between the temporary lining and the surrounding road surface can be eliminated. Therefore, it is not necessary to perform the sliding for eliminating the step, and the problem in running the vehicle and the trouble of turning around the road can be eliminated. In addition, since temporary lining and installation of a girder can be omitted, it is possible to simultaneously increase construction efficiency and reduce construction costs. According to the third aspect of the present invention, the precast concrete slab can be used as a girder or a temporary lining simply by providing a bracket on the retaining wall and installing the precast concrete slab. There is no significant change in the construction contents, and it can be easily realized.

Further, if the precast concrete slab and the side wall of the box culvert are connected by anchor bolts as in the invention of claim 4, resistance to shearing force and tensile force acting on the top of the side wall is increased. be able to.
Further, by introducing a prestress to the precast concrete slab as in the invention of claim 5, it is possible to avoid the influence of the bending displacement of the precast concrete slab due to the running of the vehicle, and to provide a paved road on the box culvert. In this case, the occurrence of cracks on the road surface can be prevented.
Further, by introducing concrete using the holes provided in the precast concrete slab as in the invention of claim 6, it is possible to avoid construction problems caused by installing the precast concrete slab first. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a construction structure of a box culvert according to an embodiment of the present invention.

FIGS. 2A to 2D are diagrams sequentially illustrating steps of a box culvert construction method according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional box culvert construction structure.

FIGS. 4A to 4D are diagrams sequentially illustrating the steps of a conventional box culvert construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground 2 Retaining wall 11 Flooring part 30 Box culvert 30A Bottom plate 30B, 30C Side wall 30D Upper slab (precast concrete plate) 31 Bracket 32 Anchor bolt

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobutaka Okutsu 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Takeshi Kenmi 2-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Yasunari Kihara 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation Co., Ltd. F-term (reference) 2D047 AB08 AC02 2D063 BA06 BA32

Claims (6)

[Claims] 1. A box culvert construction structure to be constructed underground, wherein the upper slab of the box culvert is constituted by a precast concrete plate which also serves as a cutting beam and a temporary lining when the box culvert is constructed. Box culvert construction structure. 2. When constructing a box culvert underground, an upper slab of the box culvert is constituted by a precast concrete slab, and the precast concrete slab is used as a cutting beam and a temporary lining.
A box culvert construction method, wherein a box culvert is constructed by excavating a lower ground of a precast concrete slab. 3. The method for constructing a box culvert according to claim 2, wherein a step of forming an earth retaining wall with respect to the ground, and excavating an inner ground of the earth retaining wall by a predetermined depth, to form an upper end of the earth retaining wall. A step of installing a bracket in the vicinity, supporting the bracket, and installing a precast concrete slab constituting the upper slab of the box culvert, and using the precast concrete slab as a cutting beam supporting the retaining wall and a temporary lining. Utilizing, excavating the inner ground of the retaining wall below the precast concrete slab and attaching it to the floor, and installing the bottom slab and side walls of the box culvert in the excavated space and connecting with the precast concrete slab. And a step of constructing a box culvert. 4. The box culvert construction method according to claim 3, wherein a precast concrete slab forming an upper slab of the box culvert and a side wall of the box culvert are connected by an anchor bolt. Construction method. 5. The box culvert construction method according to claim 3, wherein a prestress is introduced into the precast concrete slab to integrate the precast concrete slab. Culvert construction method. 6. The box culvert construction method according to any one of claims 3 to 5, wherein a bottom plate and a side wall of the box culvert are constructed using holes provided in the precast concrete plate. A box culvert construction method characterized by putting concrete.