JPH11181809A - Construction of large scale prestressed concrete culvert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a construction period and man-hours by forming a precast or cast-in-place concrete foundation and inserting hollow parts of the counterfort of T-shaped precast concrete blocks on protruded PC steel rods and tensing the PC steel rods after the blocks have been stacked one after another and introducing a prestress to construct an integrally formed side wall and laying precast top plates. SOLUTION: An anchorage plate 2 is fixed at a specified position of a precast or cast-in-place floor slab 1 and PC steel rods 3 are fixed to the anchorage plate 2 to assemble reinforcements for a foundation slab. The hollow parts 8 of the counterfort of T-shaped precast blocks 7 are inserted on PC steel rods 3 jointed by couplers 6 to stack the T-shaped blocks 7 and construct a side wall. A T-shaped precast receive base block 14 used for a receive base for the precast top plate 13 in common is superposed on the uppermost part of the side wall. The anchor plate 9 is inserted on the steel rods 3 and after the rods have been tensed up to a stipulated prestress, it is fastened with a nut 10. And hence, the construction work and man-hours can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a culvert having a cross section of approximately 30 m ^2.
With regard to the above-mentioned large underdrain, the construction cost will be reduced by greatly shortening the construction period of the large underdrain and reducing the number of construction personnel.

[0002]

^2. Description of the Related Art Conventionally, a large underdrain having a cross section of approximately 30 m ² or more has been constructed by using in-situ reinforced concrete.

[0003]

The cross section of a culvert is approximately 30 m.
^Two or more large culverts have a problem in the means of transportation to the construction site for precast concrete products due to the restrictions on vehicles, and most of them have been constructed using cast-in-place reinforced concrete. Therefore, according to the present invention, a precast concrete product having no problem in transportation is prefabricated, integrated by applying prestress to construct a large culvert, compared with a construction method using cast-in-place reinforced concrete,
The company is aiming to significantly reduce the construction cost by shortening the construction period and reducing the number of construction personnel.

[0004]

In order to solve the above-mentioned problems,

As shown in FIG. 1, a fixing plate (2) is fixed at a predetermined position of a precast or cast-in-place slab (1), and a PC steel bar (3) is further attached to the fixing plate (2). 4) Assemble,

[2] As shown in FIG. 2, the tip of a PC steel rod (3) formed from precast or cast-in-place foundation concrete (5) and protruded from a predetermined position is subjected to screw processing so that it can be further added to the upper part. PC added in (6)
On a steel rod (3)

FIG. 3 inserts a hollow wall (8) of a T-type precast block (7) having a retaining wall which is protruded from a front wall and a rear side surface thereof and has a hollow retaining wall for stacking to form a side wall. ,
T-type precast blocks (7) are sequentially stacked to build a side wall. At the top of the side wall, the precast top plate (1
The T-type precast cradle block (14) also serving as the cradle of (3) is superposed, and the anchor plate (9) for tensioning and fixing the PC steel bar (3) is inserted into the PC steel bar (3). Temporarily fasten with a nut (10), and tighten with a jack to the required prestress specified in the design.
0) is tightened, and mortar is injected into the hollow portion of the retaining wall (8) and the gap between the inserted PC steel rod (3) to protect it. T-type precast blocks (7) stacked in this way,
The integrated prestressed concrete side wall (12) is constructed by applying a series of prestresses to the T-type precast receiving block (14), and the precast top slab (13) is constructed.

[0005]

The tip of a PC steel bar (3) formed from a precast or cast-in-place foundation concrete (5) and protruded from a predetermined position is subjected to screw processing so that it can be further added to the upper part, and a coupler (6) PC added with
On steel rod (3)

As shown in FIG. 3, the hollow portion (8) of the retaining wall of the T-type precast block (7) is inserted and the T-type precast block (7) is sequentially stacked to form a side wall.
A T-type precast cradle block (14) also serving as a cradle for the precast top plate (13) is superposed, tensioning the PC steel bar (3) to a required prestress specified value, and applying a series of prestress. Thus, the integrated prestressed concrete side wall (12) is constructed, a precast top plate (13) is erected, and a large culvert is constructed.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

As shown in FIG. 1, a fixing plate (2) is fixed at a predetermined position of a precast or cast-in-place slab (1), and a PC steel bar (3) is further attached to the fixing plate (2). 4) Assemble,

[2] As shown in FIG. 2, the tip of a PC steel rod (3) formed from precast or cast-in-place foundation concrete (5) and protruded from a predetermined position is subjected to screw processing so that it can be further added to the upper part. PC added in (6)
On a steel rod (3)

FIG. 3 inserts a hollow wall (8) of a T-type precast block (7) having a retaining wall which is protruded from a front wall and a rear side surface thereof and has a hollow retaining wall for stacking to form a side wall. ,
T-type precast blocks (7) are sequentially stacked to build a side wall. At the top of the side wall, the precast top plate (1
The T-type precast cradle block (14) also serving as the cradle of (3) is superposed, and an anchor plate (9) for tensioning and fixing the PC steel bar (3) is inserted into the PC steel bar (3). Temporarily fix with nut (10), and after tightening to the required prestress specified by design with jack, nut (10)
Then, mortar is injected into the hollow portion of the retaining wall (8) and the gap of the inserted PC steel rod (3) to protect the hollow portion. The T-type precast block (7) stacked in this way,
The integrated prestressed concrete side wall (12) is constructed by applying a series of prestresses to the mold precast receiving block (14), and the precast top plate (13) is erected. still,

FIG. 4 shows an example of construction in a case where the side wall portion is deep. Since the earth pressure and the like increase in the lower layer closer to the base portion, the retaining wall portion of the lower T-type precast block (7) is used. (11) shows an example of construction in which the section is extended rearward from the retaining wall (11) of the upper T-type precast block (7) to increase the sectional strength and sufficiently cope with earth pressure and the like.

[0007]

According to the present invention,

As shown in FIG. 3, the back side of the side wall of the large culvert receives a tensile force when an external force such as earth pressure acts, and at the same time, receives a compressive force on the front side of the side wall. Between the side wall back side and the side wall front side,
There is a boundary surface where neither tensile force nor compressive force is generated, that is, there is a neutral surface, and the cross section in the tensile force range behind the neutral surface is almost a concrete part, and it is a luxurious part to expect the tensile force by reinforcing steel, By supplying a slim and lean economical cross section like the T-type precast block (7), the T-type precast cradle block (14), and the precast top plate (13) where the extravagant part is shaved off. The construction cost can be reduced by greatly reducing the amount of concrete used. As described above, the construction of the underdrain according to the present invention is such that the precast product produced under the sufficient quality control in the factory is tensioned to the required prestress specified value of the PC steel rod (3) at the construction site and integrated. Most of these constructions, in which the prestressed concrete side walls (12) are constructed and the precast top slab (13) is erected, are mechanical work, so that the construction period is greatly shortened and the number of personnel is significantly reduced. A great effect as a new construction method can be expected.

[Brief description of the drawings]

FIG. 1 shows a state in which a fixing plate (2) is fixed to a precast or cast-in-place slab (1), a PC steel bar (3) is further attached, and a reinforcing bar (4) for a base slab is arranged.

FIG. 2

FIG. 1 shows a state in which a foundation concrete is formed.

FIG. 3 shows a perspective view of an embodiment of the present invention in which a precast top plate (13) is erected on a prestressed concrete side wall (12) integrated by applying a prestress.

FIG. 4 is an example of use of the present invention when the side wall is deep,
FIG. 4 shows a perspective view of an embodiment in which the retaining wall portion (11) of the T-type precast block (7) is extended backward at the lower layer portion.

FIG. 5 is a perspective view of an embodiment in which the precast top slab (13) is an arch type and the precast or cast-in-place foundation concrete (5) is integrated, in an example of use of the present invention in which there is a lot of overburden.

FIG. 6 shows a perspective view of an embodiment of the present invention as a snow shelter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Precast or cast-in-place slab 2; Fixing plate 3; PC steel bar 4; Reinforcing bar for base slab 5; Precast or cast-in-place foundation concrete 6; Coupler 7; 10; nut 11; retaining wall portion 12; prestressed concrete side wall 13; precast top plate 14; T-type precast cradle block 15; steel shelter 16; lighting window 17;

Claims (1)

[Claims] 1. A fixing plate (2) is fixed to a predetermined position of a precast or cast-in-place slab (1) as shown in FIG. 1, and a PC steel rod (3) is attached to the fixing plate (2). Assembling the rebar (4) for the base bottom slab, forming the precast or cast-in-place foundation concrete (5) as shown in FIG. PC that has been threaded in the same way and added with a coupler (6)
FIG. 3 shows a T-shaped precast block (7) having a front wall and a rear side surface protruding from a steel rod (3) and having a hollow wall for forming a side wall by stacking. Insert part (8),
T-type precast blocks (7) are sequentially stacked to build a side wall. At the top of the side wall, the precast top plate (1
The T-type precast cradle block (14) also serving as the cradle of (3) is superposed, and an anchor plate (9) for tensioning and fixing the PC steel bar (3) is inserted into the PC steel bar (3). Temporarily fix with nut (10), and after tightening to the required prestress specified by design with jack, nut (10)
Then, mortar is injected into the hollow portion of the retaining wall (8) and the gap of the inserted PC steel rod (3) to protect the hollow portion. The T-type precast block (7) stacked in this way,
A method of constructing a large culvert in which an integrated prestressed concrete side wall (12) is constructed by applying a series of prestresses to a mold precast receiving block (14), and a precast top plate (13) is erected.