JP2665164B2 - Box culvert - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box culvert, and more particularly, to a box culvert for dropping an upper portion having a convex portion and a concave portion at front and rear ends, respectively.

[0002]

2. Description of the Related Art In particular, box culverts used as large culverts for sewers are constructed by assembling reinforcing steel on site and then pouring ready-mixed concrete into a formwork. There are two types of secondary products that are manufactured and cured and suspended and laid by a crane or the like as secondary products.

[0003] The cast-in-place box culvert can be obtained in various structures according to the spatial conditions of the site, particularly those having a large cross section. Is difficult to cure, and there is a quality problem especially in winter. In contrast, box culverts for secondary products have relatively high product quality,
Also, since the construction period on site can be significantly reduced,
Box culverts with an inner diameter of up to about 2500 × 2500 mm are occupying the mainstream.

[0004] Such a box culvert as a secondary product is usually formed to have a length of about 2 m, and is laid in a predetermined extension with its front and rear facing each other.

The most common method of laying a box culvert is to place a box culvert at a predetermined position on a concrete foundation, move the next box culvert on the foundation and then move it horizontally to lay the box culvert forward. Join to the end face of the box culvert.

As a device for facilitating the horizontal movement of such a box culvert, the applicant of the present application has adopted a bogie capable of horizontally moving with a box culvert mounted thereon.
This is proposed in JP-A-2-35095.

However, in the method of moving the box culvert to be laid in the horizontal direction, it is difficult to accurately move the heavy box culvert so that the end faces do not shift from each other. Therefore, there is a problem that it takes time to move in the horizontal direction and construction efficiency is poor.

As a countermeasure against this, for example, design registration No. 59
Japanese Patent Application Publication No. 9902 proposes a so-called underdrain block for dropping an upper part, in which a block is dropped from above and joined.

This culvert block is formed with a joint convex portion and a U-shaped concave portion for fitting the convex portion on the front and rear ends, respectively. The culvert block is laid first while the culvert block is hung by a crane or the like. The tip end of the culvert block to be laid is pressed against the end of the culvert block that has been laid and suspended from above.

With such a structure, the above problem in the box culvert of the horizontal movement type can be solved. Further, the problem of water leakage from the joint surface due to the fitting of the concave portion and the convex portion can be compared. It is hard to happen.

[0011]

However, the culvert block for dropping the upper part described in the above publication is merely abutting the end faces of the culvert block formed substantially vertically. In the worst case, water is leaked from the joint surface, and in severe cases, earth and sand leak from the joint surface into the culvert block after being buried in the ground, causing road surface collapse. In order to prevent this, careful caulking of the joint material to the joint surface is required.

Also, since the joint surface of the conventional underdrain culvert block, that is, the convex portion and the concave portion are formed only in the shape of irregularities so that a part of the concrete body can be fitted, the convex portion and the concave portion are not provided. Cannot be brought into close contact with each other, and the water stopping effect is poor. As a countermeasure, it is conceivable to attach a sealing material for waterproofing to the joint surface. However, unlike a box culvert of a horizontal movement type, the sealing material is easily peeled off due to friction between the convex portion and the concave portion during suspension.

Furthermore, in the conventional box culvert, the hanging hook is provided at the position of the center of gravity of the box culvert, so that when the box culvert is hung by a crane or the like, the abutting surface becomes substantially vertical. There is also a problem that the entire vertical surface is hung in contact with the end face of the previously laid box culvert, and it is difficult to perform construction due to frictional resistance.

An object of the present invention is to solve the above-mentioned problems in a conventional box culvert for dropping into an upper part. A first object of the present invention is to prevent the leakage of earth and sand from a joint surface with a relatively simple structure. The second purpose is to enhance the water stopping effect without significantly affecting the workability, and the third purpose is to facilitate the suspension of the box culvert and improve the workability.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned first object, the present invention provides a box culvert in which a convex portion and a concave portion are formed at the front and rear ends, respectively. And a cover that projects forward from the abutting surface of the box culvert during joining.

Further, the second object can be achieved by disposing a sealing material for stopping water having an anchor member on a joint surface of the concave portion or the convex portion.

Here, the abutting surface of the box culvert refers to the end surface of the box culvert, and the joining surface refers to the contact surface outside the convex portion and inside the concave portion, respectively.

Further, the third object can be achieved by providing a hanging hook on the side of the convex portion with respect to the position of the center of gravity. Here, the installation position of the hook refers to the installation position when there is only one hook, and refers to the acting position of the resultant force when there are multiple hooks.

[0019]

When the box culvert is joined, the cover formed on the upper end of the projection covers the upper part of the butted surface of the box culvert.

Also, by providing the seal member with the anchor member, it is possible to firmly fix the seal member so that the seal member is not peeled off by friction when dropped from above.

Further, by providing the hook for suspension on the convex side than the position of the center of gravity, the end surface of the box culvert is inclined with respect to the vertical line during suspension.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments shown in the drawings. FIG. 1 is a perspective view of a box culvert according to one embodiment of the present invention, FIG. 2A is a front view of the box culvert shown in FIG. 1, and FIG. 2B is FIG.
2A is a sectional view taken along the line AA, and FIG. 2C is a sectional view taken along the line BB in FIG.

The box culvert 10 of this embodiment is a so-called upper drop box culvert, which is fitted with the convex portion 1 at one end (front end side) and this convex portion 1 at the other end (rear end side). A matching recess 2 is formed.

The convex portion 1 has, at its upper portion, a cover portion 1a projecting forward from the vertical butting surface S when the box culvert is joined, and a notch portion 1b at its lower portion into which the lower end of the concave portion 2 enters. Has formed.

On the other hand, the recess 2 has two side surfaces 2a and a bottom surface 2b.
Formed in a U-shape with the upper surface open, and the side surface 2a
Has a gradient of 3%, the width of which decreases downward with respect to the vertical axis, and the bottom surface 2b is formed horizontally. By providing the side surface 2a with a gradient in this manner, the side surface 2a is not caught and the dropping from above is made easier.

As clearly shown in FIGS. 1 and 2 (b), a sealing member 3 having an anchor 3a is attached to the side surface 2a and the bottom surface 2b of the concave portion 2, that is, the joining surface when concrete is poured. ing. This sealing material 3 is shown in FIG.
As shown in (c), it is similarly provided on the lower surface of the cover 1a. In addition, an insertion portion 4 into which the sealing material enters is formed at a location corresponding to the sealing material 3 at the time of joining, as shown in FIG. With such a structure, formation of a gap due to the provision of the sealing material 3 is prevented.

The material of the sealing material 3 is desirably an ethylene propylene single foam sponge, particularly in view of resilience and long-term durability. Further, the sealing material 3 can be provided not only on the joint surface of the concave portion 2 but also on the outer side of the convex portion 1 as in the present embodiment, but the convex portion 1 is placed on the concave portion 2 side of the box culvert. It is desirable to provide on the inner surface of the recess 2 because it is laid. Further, a lubricant such as hydrophilic polyurethane can be applied to the surface of the sealing material 3 in order to improve the slip at the time of fitting.

As described above, by providing the seal member 3 with the anchor on the inner surface of the concave portion 2, the seal member 3 is compressed and deformed by the weight of the box culvert 10 itself, and the water stoppage of the joint surface is automatically performed by hanging. Can be secured. At this time, since it is provided with an anchor, peeling and turning up can be easily eliminated even by contact at the time of hanging.

H ₁ and H ₂ are a pair of hooks provided on the top plate of the box culvert 10, and as shown in FIG. 2C, the point of action of the resultant force P of the hooks H ₁ and H ₂ is The culvert 10 is eccentric to the convex side 1 by a distance e from the center of gravity NA of the culvert 10. As a result, when the box culvert is hung by a crane or the like, the box culvert is not in a horizontal state but in a state inclined to the concave portion 2 side.

Therefore, when the convex portion 1 of the box culvert 10 is hung into the concave portion 2 of the box culvert 10 already laid, unlike the conventional case, the entire butting surface of the box culvert 10 does not contact, and The construction can be performed in a state in which only the lower end portion is in contact, the frictional resistance is reduced, and the workability is greatly improved. This eccentricity e
It is enough if the abutment surface is slightly inclined
Conversely, if it is too large, it will be too tilted and adversely affect the construction, so that the range of about 5 to 10 cm from the center of gravity position NA is preferable.

Next, a specific laying method of the box culvert will be described with reference to FIG.

In FIG. 3A, reference numeral 5 denotes a foundation quarry, 6 denotes a foundation concrete constructed on the foundation quarry 5,
A state where box culverts 10a to 10c are laid at predetermined positions on the foundation concrete 6 is shown.

Next, as shown in FIG. 3 (b), when the box culvert 10 is lifted by a crane (not shown), as shown in FIG. 2 (c), the resultant force P of the hooks H ₁ and H ₂ is increased. Since the action point is eccentric to the convex side 1 by the distance e from the center of gravity NA of the box culvert 10, the concave part 2 side is lowered and the convex part 1 side is raised.

In this state, while applying a force in the direction of the box culvert 10c already laid, the lower end of the convex portion 1 of the box culvert 10d is brought into contact with the box culvert 10c.
And gradually descend.

In this way, it can be laid in the state shown in FIG. In this state, as shown in FIG. 4, the cover 1a of the convex portion 1 covers the joint surfaces of the box culverts 10c and 10d, thereby preventing leakage of water and earth and sand from gaps between the joint surfaces. Further, since the sealing material 3 is provided on all of the joining surfaces, it is possible to secure the water stoppage.

[0036]

According to the present invention, the following effects can be obtained.

(1) The cover formed at the upper end of the projection covers the upper part of the butted surface of the box culvert when the box culvert is joined, thereby preventing leakage of earth and sand from the joint surface. it can.

(2) By disposing a water-stopping sealing material having an anchor member on the joint surface of the concave portion or the convex portion, the water-stopping effect can be enhanced without significantly affecting the workability.

(3) By providing the hanging hook on the protruding portion side from the position of the center of gravity, the end surface of the box culvert is inclined with respect to the vertical line during the hanging, so that the frictional resistance is reduced and the box culvert is reduced. The workability of hanging the culvert is improved.

[Brief description of the drawings]

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

2A is a front view of the box culvert shown in FIG. 1, FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line BB in FIG.

FIG. 3 is a view showing a procedure for performing the box culvert shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a main part in a joined state.

[Explanation of symbols]

First convex portion 1a covering portion 1b notch 2 recesses 2a side 2b bottom third seal member 3a anchor 5 basis Quarry 6 foundation concrete 10 box culvert S abutting surfaces H _1, H ₂ hooks

Claims (3)

(57) [Claims] 1. A box culvert having upper and lower projections and depressions formed at front and rear ends, respectively, wherein a cover projecting forward from an abutting surface of the box culvert at an upper end of the projection when joining. A box culvert characterized by forming. 2. The box culvert according to claim 1, wherein a seal member for stopping water having an anchor member is provided on a joint surface of the concave portion or the convex portion. 3. The box culvert according to claim 1, wherein a hook for suspension is provided on a side of the convex portion with respect to a position of a center of gravity.