JP2000273938A - Precast concrete block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast concrete block for use in a culvert block or a retaining-wall block in a horizontal pulling method for constructing a culvert, a retaining wall or the like, which has easily and economically formed projections for abutting on a bearing, facilitates securing of cover concrete for reinforcing bars and arrangement of the reinforcing bars, and is excellent in life and safety. SOLUTION: A box culvert 1-1 formed of precast concrete is guided and supported by a guide rail 2 laid on foundation concrete 11, and bearing balls 3 and cylindrical rollers disposed in a concave groove 2a of the rail, and it is delivered to a predetermined installation portion to be rigidly set to the same. The lower surface of a base 1a of the box culvert 1-1 has concrete projections 5 which each are integrally formed together with the base 1a and protrude from the same. The projections having a rectangular cross section, are each inserted into the concave groove 2a of the guide rail 2 with sufficient gaps on both right and left sides. The surface of each projection 5 is covered with a steel plate 6 functioning as a form when produced, to be reinforced by the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a culvert block such as a box culvert or an arch culvert, or a precast concrete block such as a retaining wall block. The block is transferred along a rail and is sequentially fixed at an installation position. Effectively applied such as horizontal drawing method.

[0002]

2. Description of the Related Art In urban sewerage works and the like, precast concrete unit length culvert blocks (supported by piled walls such as steel sheet piles) and made of a precast concrete through a carry-in entrance in an open-cut tunnel excavated to a predetermined ground surface. Box culverts) are suspended on the foundation concrete at the bottom of the excavation tunnel, and the culvert block is transferred along a pair of guide rails laid on the foundation concrete by a drive device such as a winch-wire system, and is sequentially installed at the installation position. The horizontal drawing method is adopted to build a fixed and continuous culvert.

In such a horizontal drawing method, as shown in FIG. 6, a bearing ball (steel) is provided between a lower surface of a bottom plate 1a of a precast concrete block 1 such as a box culvert and a guide rail 2 such as an H-section steel. A ball bearing 3 and a cylindrical roller 4 are provided to reduce the friction at the time of horizontal pulling. A conventional box bearing employs a block 1 as shown in FIG. 6 (a). A projection 50 made of a thick steel plate inserted into the groove 2a of the guide rail 2 (H-section steel or the like) protrudes from the lower surface of the bottom plate of the block 1 or, as shown in FIG. The notch 51 is provided by an embedded metal fitting into which the upper part of the guide rail 2 (railroad rail shape or the like) is inserted.

[0004]

However, the conventional projections 5
In the case of 0, insert metal fittings for fixing the thick steel plate to the concrete block main body and processing for countersunk bolts for mounting the thick steel plate, etc. are required, which is costly, and the plates are stacked or bolted. Therefore, there is also a problem that the thick steel plate is displaced. In addition, iron lump was also present in durability, which was not preferable.

Further, in the case of the conventional notch 51, there is a problem that it is difficult to secure the cover of the reinforcing bar embedded in the block body and to arrange the reinforcing bar. The present invention has been made in order to solve the above-described problems, and an object thereof is to contact a bearing in a culvert block or a retaining wall block used in a horizontal drawing method for constructing a culvert or a retaining wall. An object of the present invention is to provide a precast concrete block which is easy and economical to form projections, secures a cover of a reinforcing bar, easily arranges a reinforcing bar, and has excellent durability and safety.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a rail is laid on a foundation concrete and a rolling member (such as a bearing ball or a cylindrical roller) disposed in a groove of the rail guides and supports a predetermined installation. A precast concrete block (such as a culvert block or a retaining wall block) which is transported to a position and fixed at the installation position. The block bottom plate is provided with a projection made of concrete in a shape that can be inserted into the concave groove on the lower surface of the block bottom plate. (Claim 1).

The surface (bottom surface, both side surfaces, and, if necessary, both end surfaces in the longitudinal direction of the rail) of the concrete protrusion is covered with a steel plate to reinforce the protrusion. The projections are formed continuously in the rail longitudinal direction when the guide rail is straight (claim 3), and are formed at intervals in the rail longitudinal direction when the guide rail has a curve, and have a short length. Projections (claim 4).

In the above configuration, since the projections made of concrete are integrally projected from the bottom plate of the precast concrete block, there is no need to process insert metal fittings, bolts or steel plates unlike the conventional steel plate projections. Protrusions can be formed easily and economically. Further, since there is no insert metal fitting or the like or a notch concave portion as in the related art, it is easy to secure the cover of the reinforcing bar and to arrange the reinforcing bar.
Furthermore, since the integrally protruded concrete is covered with the steel plate, the steel plate does not shift as in the case of the conventional steel plate protrusion, and the durability and safety are excellent.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. 1 shows an example in which the present invention is applied to a box culvert, FIG. 2 shows an example in which the present invention is applied to an arch culvert, and FIG. 3 shows an example in which the present invention is applied to a retaining wall block. FIG. 4 shows a modification in which the shape of the protrusion in the rail longitudinal direction is changed. FIG. 5 shows an example of the horizontal drawing method.

In FIG. 1, a concrete rectangular cross section which is inserted into a concave groove 2a of a guide rail 2 with sufficient clearances on both left and right sides is inserted into a lower surface of a bottom plate 1a of a box culvert 1-1 made of precast concrete. The projection 5 is integrally provided from the bottom plate 1a.

The guide rail 2 is formed by embedding an H-section steel in the foundation concrete 11 so that a concave groove 2a is formed by the upper portion of the parallel flange with the web, and a bearing ball (upper surface of the web) is formed on the bottom surface (upper surface of the web) of the concave groove 2a. Many steel balls) 3 are laid. In addition, the guide rail 2 is not limited to this,
As shown in FIG. 6 (b), a rail-shaped rail is used, and a guide bar (a steel bar, a flat steel, or the like) is fixed to both sides of the head of the rail by welding or the like to form a concave groove 2a. And so on. The rolling element is not limited to a bearing ball, but may be a cylindrical roller or the like.

The projection 5 has a bottom surface mounted on the bearing ball 3 and the like, and both side surfaces are in contact with both side walls (inner side surfaces of the flange) of the guide rail 2. Both sides are covered, and both ends in the longitudinal direction of the rail are covered if necessary, so that the concrete of the projections 5 is not damaged. The steel plate 6 is made of a web 6a.
And left and right flanges 6b and left and right projecting pieces (lip pieces) 6c
The protrusions 5 and the steel plate 6 can be integrated by inserting the left and right projecting pieces 6c into the concrete. Furthermore, the steel plate 6 is attached to the outer formwork at the time of manufacturing the box culvert 1, and concrete is poured in after the necessary reinforcement is arranged, so that the steel plate 6 becomes the formwork of the protrusion 5 and the protrusion 5 and the steel plate 6 1
-1.

Further, as shown in FIG. 1 (d), haunches 5a are formed on both side surfaces of the projections 5 to form inverted trapezoidal projections 5 '.
The strength of the protrusion may be improved. The steel plate 6 may also have an inverted trapezoidal shape. In addition, if necessary,
As shown by the two-dot chain line in FIG. 1 (b), haunches 5b are also formed on both end surfaces of the protrusion 5 in the rail longitudinal direction to improve the strength of the end of the protrusion 5 and to make the bearing ball 3 To make it easy to get underneath.

When the guide rail 2 is formed in a straight line with respect to the rail longitudinal direction of the projection 5, the guide rail 2 is provided continuously at an intermediate portion in the rail longitudinal direction so that it can slide on the bearing ball 3 smoothly. Further, in order to bring the joining surfaces of the box culverts into close contact with each other at the installation position without any trouble, it is preferable that the projections 5 are not provided at both ends in the rail longitudinal direction.

Further, as shown in the lower part of FIG. 1 (b), a plurality of holes (notches) 5c penetrating in the lateral direction are formed below the protrusions 5 at intervals in the longitudinal direction of the rail, and a box culvert described later is formed. The area around the grout material for fixing may be improved. Further, as shown in FIG. 1 (e), the upper portion of the steel plate 6 may be buried in the bottom plate 1a to improve the projection strength.
As shown in (2), the corners of the protrusions 5 are rounded or rounded, so that the area around the grout material can be improved.

FIG. 2 shows an example of an arch culvert 1-2, and FIG. 3 shows an example of a retaining wall block 1-3 applied to a wall member such as a water channel or a retarding pond. As described above, the protrusion 5 (or the haunch 5a or 5c) is used.
b) and a steel plate 6 are provided.

FIG. 4 is designed to cope with the case where the guide rail 2 is curved. The projections 5 are not continuous with each other in the longitudinal direction of the rail. A plurality of short protrusions 5 are provided so that they can pass through the concave groove 2a of the curved guide rail 2. Also in this case, the bottom surface and both side surfaces of the projection 5 and both end surfaces in the rail longitudinal direction are covered with the steel plate 6 as necessary.

Next, one of the horizontal drawing methods using a precast concrete block having a bottom plate projection as described above is described.
An example will be described (see FIG. 5). This is an example of a box culvert.

(1) Two guide rails 2 are laid on the foundation concrete 11 constructed at the bottom of the excavation tunnel 10, and a number of bearing balls 3 are laid in grooves in the guide rails 2.

(2) In the side view of FIG.
The box culvert 1-1 having a unit length is sequentially carried in on the guide rail 2 by using the crane 14 from the carry-in entrance 13 formed in the guide 2, and is set so that the projection 5 is located in the concave groove of the guide rail 2. .

(3) The tip of the wire rope 16 of the winch 15 is connected to a connection hole formed in the upper surface of the bottom plate of the box culvert 1-1, and the winch 15 is operated to place the box culvert 1-1 at a predetermined installation position. Pull in until.

(4) A packing material is attached to the joining end of the box culvert 1-1, and the box culverts are joined to each other at the installation position by using a PC steel rod and a coupler.

(5) Connected box culvert 1-1
Is only supported on the guide rail 2 via the bearing ball, and the grout material 18 is injected into the gap between the box culvert 1-1 and the foundation concrete 11 from the grout hole 17 of the bottom slab, and the box culvert 1-1 is formed.
Is fixed on the foundation concrete 11.

(6) A gap between both sides of the box culvert 1-1 is filled with sand, poorly-mixed concrete, or the like, and the upper portion is backfilled to form a continuous culvert. In the case of the retaining wall block as well, the blocks are successively carried in from the loading point, transferred to a predetermined installation position, and fixed by installation, thereby constructing a continuous waterway or a wall of a retarding pond. Further, it goes without saying that the present invention can be applied not only to the illustrated culvert block and retaining wall block but also to other precast concrete blocks. Further, it goes without saying that the present invention can be applied not only to the horizontal pulling method using a winch and a wire but also to other moving installation methods.

[0025]

The precast concrete block according to the present invention has the above-described structure, and can provide the following effects.

(1) Since the concrete projections protrude integrally from the bottom plate of the precast concrete block, there is no need to process insert metal fittings, bolts, or steel plates as in the case of conventional steel plate projections. It is easy and the cost of the box bearing type block in the horizontal drawing method or the like can be reduced.

(2) Since there is no insert metal fitting or the like or a notch concave portion as in the prior art, it is easy to secure the cover of the reinforcing bar and to arrange the reinforcing bar. (3) Since the integrally protruding concrete is covered with the steel plate, the steel plate does not shift as in the case of the conventional steel plate protrusion, and is excellent in durability and safety.

(4) An arbitrary projection height can be easily obtained by changing the dimensions of the steel plate serving as the formwork of the projection at the time of manufacturing the block.

[Brief description of the drawings]

FIG. 1 is a box culvert with projections of the present invention,
(a) is a front view, (b) is a side view, (c) is an enlarged cross-sectional view of a protruding portion, (d) is an enlarged cross-sectional view of a modification in which the cross-sectional shape of the protruding portion is different, and (e) is an enlarged cross-sectional view of the protruding portion. FIG. 9F is an enlarged cross-sectional view of a modification in which the position of the steel plate is changed, and FIG.

FIG. 2 is an arch culvert with projections according to the present invention;
(a) is a front view and (b) is a side view.

FIG. 3 is a retaining wall block with a projection of the present invention, wherein (a) is a front view and (b) is a side view.

4A and 4B are a front view and a side view showing an example of a block in which protrusions of the present invention have different shapes in the rail longitudinal direction, wherein FIG. 4A is a box culvert, FIG. 4B is an arch culvert, and FIG. Is the case.

FIG. 5 is an example of a horizontal drawing method of a precast concrete block, in which (a) is a side view, (b) is a plan view, and (c) is a cross-sectional view showing a process order.

6A is a cross-sectional view showing a projection on a conventional culvert block, and FIG. 6B is a cross-sectional view showing a projection on a conventional culvert block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Precast concrete block, 1a ... Bottom plate 1-1 ... Box culvert 1-2 ... Arch culvert 1-3 ... Retaining wall block 2 ... Guide rail, 2a ... Groove 3 ... Bearing ball (steel ball) 4 ... ... Cylindrical roller 5 ... Protrusion, 5 '... Protrusion with haunch 6 ... Steel plate 10 ... Cutting tunnel 11 ... Foundation concrete 12 ... Working plate 13 ... Transport entrance 14 ... Crane 15 ... Winch 16 ... Wire rope 17 Grout hole 18 Grout material

Continued on the front page (72) Inventor Tadashi Iwasaki, 4-2-2, Shiba, Minato-ku, Tokyo Inside Geostar Co., Ltd. (72) Inventor Yusuke 4-2-2, Shiba, Minato-ku, Tokyo Inside Geostar, Inc. ( 72) Inventor Mikio Tsutsumi 4-3-3 Shiba, Minato-ku, Tokyo Geostar Co., Ltd. (72) Inventor Yoshihiro Imagawa 4-2-2-3 Shiba, Minato-ku Tokyo, Japan Geostar Co., Ltd. (72) Keiichi Watanabe 4-3 2-3 Shiba, Minato-ku, Tokyo Inside Geostar Co., Ltd. (72) Inventor Noshinari No. 3-12-8 Shibaura, Minato-ku, Tokyo Ando Construction F-term (reference) 2D063 BA06 BA07 BA32

Claims (4)

[Claims] 1. A precast concrete block which is guided and supported by a rail laid on a foundation concrete and a rolling element disposed in a groove of the rail, transferred to a predetermined installation position, and fixedly installed at the installation position. A precast concrete block comprising: a lower surface of a block bottom slab, wherein a projection made of concrete is inserted from the block bottom slab so as to be inserted into the concave groove. 2. The precast concrete block according to claim 1, wherein the surface of the projection is covered with a steel plate. 3. The precast concrete block according to claim 1, wherein the protrusions are formed continuously in the rail longitudinal direction. 4. The precast concrete block according to claim 1, wherein the protrusions are formed at intervals in the rail longitudinal direction.