JP2891670B2 - Flexible joint structure of concrete product and concrete product having the flexible joint structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various concrete blocks for constructing sewers, irrigation canals, passageways, open channels, underground passages, common ditches, etc., including box culverts and pipe culverts for constructing culverts. The present invention relates to a flexible joint structure of a concrete product for connecting with flexibility and a concrete product having the flexible joint structure.

[0002]

2. Description of the Related Art An underdrain, an underpass, a common ditch, etc. constructed by connecting precast concrete products may be damaged or even destroyed due to an earthquake or uneven settlement, in which a product body and a joint between products are sometimes broken. . For this reason, conventionally, this is dealt with by providing a flexible joint structure at a joint between products. This flexible joint structure is generally formed with a notch portion one step lower than the end surface on the inner peripheral side of the end portion of the concrete product over the entire circumference, and an insert nut or the like is embedded in the notch portion in advance, At a construction site, a flexible joint member made of, for example, a rubber material is interposed between end surfaces of adjacent concrete products. Specifically, the attachment portion of the flexible joint material is brought into close contact with the notch portion, and a holding steel plate is attached to the flexible joint material. Then, a stop such as a bolt inserted through the steel plate and the flexible joint material is stopped. A concrete product is connected by a flexible joint material by fastening a fitting to the insert nut to form a flexible joint.

[0003]

By the way, a flexible joint material in such a flexible joint structure is formed by bending a horseshoe-shaped or substantially U-shaped flexible portion and bending its end outward. And a mounting portion, which is mounted on the cutout portion of the concrete product such that the flexible portion protrudes inside the product main body. The notch is generally formed of a plane parallel to the end face, that is, a plane one step inside from the end face, and the mounting portion of the flexible joint material is fixed.

[0004] Such a flexible joint material is attached at a construction site with its flexible portion exposed inside the product body. For this reason, the flexible portion is curved in a convex shape inside the product body. After the construction is completed,
This flexible portion is subjected to water pressure by water in the soil. When the water pressure increases, the flexible portion is easily deformed because the flexible portion is curved in a convex shape inward, and the water stopping performance may be reduced.

In the above-described notch structure, when a concrete product is manufactured, for example, when concrete is poured into a formwork with the end face in the connecting direction of the concrete product being up and down, Bubbles inside may collect on the inner surface of the formwork for forming the notch. When the concrete hardens in a state where the air bubbles are collected in this way, irregularities are generated on the contact surface between the cutout portion and the flexible joint material, and the watertightness of the portion is reduced. For this reason, there arises a problem that the watertight performance of the portion in the flexible joint structure is reduced as compared with other connection portions. Further, the cutout portion is thinner than the end face portion, and a crack may be generated at the boundary portion due to a difference in thickness from the end face portion.

An object of the present invention is to solve such a problem.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a flexible product having a flexible portion which deforms notches at opposite end faces of a concrete product in response to displacement of the concrete product. A flexible part is inserted between the end faces so as to bridge with a flexible joint material and improve deformation resistance against water pressure from outside the concrete product. Therefore, the water stopping performance can be improved, and since the end surfaces of the concrete product do not rub against each other due to friction of the flexible portion, damage to the concrete product can be suppressed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A flexible joint structure for a concrete product according to the present invention provides a structure in which one concrete product is displaced by the other concrete product between opposing end faces of two concrete products arranged substantially on the same straight line. A flexible joint structure of a concrete product that is connected with flexibility so that it can be independently displaced, wherein notches are provided at opposing end faces of each concrete product, and the notches of each concrete product are formed. Bridging with a flexible joint material having a flexible portion that deforms in accordance with displacement, inserting the flexible portion of the flexible joint material between opposing end faces, and
Easily deformable EPDM sponge rubber is applied to the gap inside the flexible part.
It is characterized by being provided between them.

[0009] In order to avoid concentration of air bubbles in the notch during the production of the concrete product itself to be connected, the notch is preferably formed as an inclined surface inclined toward the rear of the end face. A concrete product having the above-described flexible joint structure includes two product bodies of the same shape having a notch at one end face in the connection direction, and a notch having a flexible portion that is deformed in accordance with the displacement of the product body. A flexible joint material for bridging by inserting both cutouts of the respective product main bodies with the portions opposed to each other and inserting a flexible portion between both end surfaces, and respective products bridged by the flexible joint material It is preferable to provide a temporary fixing member for temporarily rigidly connecting the main body. Even in this concrete product, in order to avoid concentration of air bubbles in the notch portion during production of the product main body, the notch portion is preferably formed with an inclined surface inclined toward the rear of the end face.

When a culvert or the like is constructed using the flexible joint structure of the present invention, uneven settlement or an earthquake occurs at the construction site,
If the ground on which each connected concrete product is placed separates or shifts in the vertical direction, the concrete product relatively moves in accordance with the movement of the ground and becomes flexible. The flexible part of the flexible joint material is deformed. Therefore, each concrete product can naturally follow the change in the ground, and effectively secure continuity at the connection portion.

[0011] By inserting the flexible portion of the flexible joint material between the end faces in this manner, it is possible to improve the deformation resistance to the water pressure from the outside of the concrete product, and thus to improve the waterproofness. Can be improved. In addition, when the concrete product is deformed in the connected state in the axial, shearing and bending directions due to uneven settlement, etc., the flexible parts come into contact between the end faces, so that the friction between the end faces of the concrete product is higher than when the end faces rub against each other. Coefficient is smaller,
It facilitates movement in each direction during deformation. As a result, the butt friction resistance of the concrete product is reduced and the pressure is dispersed, so that damage to the concrete product can be reduced.

In the case of manufacturing a product body of a concrete product, if the cutout portion has an inclined surface, air bubbles generated at the time of placing concrete move upward along a mold for forming the inclined surface. Therefore, it does not stop at the inclined surface portion. For this reason, after the concrete hardens, no air bubbles remain in the notch, so that the surface of the notch can be smoothed and the watertightness can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a precast box culvert A for constructing a culvert, which is a type of concrete product. This box culvert A employs a flexible joint structure K according to the present invention in a connecting portion of culvert components a1 and a2, which are product bodies, and connects a top plate 1 and a bottom plate 2 by left and right side walls 3. The culvert components a1 and a2 of the structure, the flexible joint material 4 for connecting the culvert components a1 and a2 with flexibility, and the culvert components a1 and a2 being rigid until the construction is completed on site. It is composed of an outer connection fitting 5 as a temporary fixing member to be connected. After the box culvert A is manufactured at the factory, as shown in FIG. 5, the other end faces of the box culverts A and B are connected to each other by on-site construction. For this purpose, the box culvert A has a sheath hole 8 formed at the factory stage in a connecting direction, that is, a direction penetrating between one end surface 6 and the other end surface 7 along four corners in a cross section thereof, and is formed on site. , Adjacent box culvert B
Alternatively, a PC steel rod (not shown) is inserted into the sheath holes 8 so as to straddle between C and C, and one end of the PC steel rod is connected to a culvert constituent part a1, a box culvert A.
a2 is guided into a connection box 8a provided inwardly opened at the center of each of the a2, and at this position, a nut is screwed onto a PC steel rod and fastened to the inner end face of the connection box 8a.
In box culverts B and C, the same nut tightening work is performed, so that the end faces between culvert component a1 and box culvert B or between culvert component a2 and box culvert C are brought into close contact with each other. They are connected.

As shown in FIGS. 2 to 4, the flexible joint structure K according to this embodiment is provided between the opposing end faces 9a and 9b of two culvert components a1 and a2 arranged on substantially the same straight line. One culvert component a1 is connected so that it can be displaced independently of the displacement of the other culvert component a2, and the notches 10 are formed in opposing end faces 9a, 9b of the respective culvert components a1, a2. And a flexible joint member 4 having a flexible portion 4a for deforming the notch 10 of each of the culvert components a1 and a2 in accordance with displacement.
And the flexible portion 4a of the flexible joint member 4 is inserted between the opposing end surfaces.

The culvert components a1 and a2 are provided around the inner edges of the end surfaces 9a and 9b on the side connected by the flexible joint member 4, behind the end surfaces 9a and 9b, in other words, the culvert components a1 and a2. The cutout 10 has an inclined surface that is inclined toward the depth direction a2. The notch 10 is inclined at an angle of, for example, 45 ° from the end face, and is inserted at a predetermined pitch at a position deviated from the center in the width direction to the depth direction side, with an insert nut 11 for mounting the flexible joint member 4 at a predetermined pitch. Is buried. A cut bolt 12 as a fastener is screwed to the insert nut 11. As shown in FIG. 4, the width of the notch 10 is
When bridging between the opposing end surfaces 9a and 9b with the flexible joint member 4, the mounting portion 4b of the flexible joint member 4 and the head of the cut bolt 12 are moved from the inner surfaces of the culvert components a1 and a2. It is formed so as not to protrude. Further, bolts 5a for fixing the outer connection metal fittings 5 are screwed into four upper and lower portions on the outer surface of the flexible joint structure K connected by the flexible joint members 4 of the culvert components a1 and a2. I have.

On the other hand, the flexible joint member 4 is made of, for example, butyl rubber so as to be elastically deformable.
A flexible portion 4a for connecting the two substantially culvert components a1 and a2 with flexibility, and a mounting portion 4b formed at both ends of the flexible portion 4a and fixed to the cutout portion 10. Become. The flexible portion 4a has a substantially U-shaped cross section, and has a thickness that can be inserted into a gap between the end surfaces 9a and 9b. On the other hand, the mounting portion 4b is smaller than the width dimension of the notch portion 10, and a mounting hole 4c through which the small-sized bolt 12 penetrates at a predetermined pitch is provided at the center in the width direction.

The flexible joint member 4 is made up of two culvert components a1, a2 arranged at a predetermined interval.
By fixing the mounting portion 4b to each of the notches 10, the flexible joint structure K is formed between the culvert forming portions a1 and a2, and the box culvert A is manufactured. That is, when the flexible joint member 4 is attached, the flexible portion 4a is inserted into the gap formed between the end surfaces 9a and 9b, and
b is passed through each of the cut bolts 12 in the mounting hole 4c and is brought into close contact with the notch 10. The mounting portion 4b is closely attached to the cutout portion 10 via a sheet material made of water-expandable rubber or butyl rubber, and is fixed by being fastened by a nut 15 via a fixing plate 13 and a washer 14.

The gap inside the flexible section 4a is filled with, for example, EPDM sponge rubber 16 so that foreign matter does not enter the inside of the flexible section 4a inserted into the gap. The gap between the end faces 9a and 9b is filled with, for example, EPDM sponge rubber 17 from the outside, and the outside of the EPDM rubber 17 is sealed with a sealing material 18. By preventing foreign matter from entering the flexible portion 4a, it is possible to prevent the deformation of the flexible portion 4a from being hindered by the foreign material. Thus, the flexible joint structure K between the culvert components a1 and a2 has a structure that reliably prevents foreign substances from entering from both the inside and the outside of the culvert components a1 and a2. Since the two culvert components a1 and a2 connected by the flexible joint structure K are flexible in this state, the culvert component a2 is not lifted at the same time when the culvert component a1 is lifted up. So
The outside is rigidly connected by the outer connection fitting 5, and the flexibility of the connection portion is temporarily prohibited until the outer connection fitting 5 is removed, so that it can be handled as one box culvert.

In the box culvert A, since the notches 10 of the culvert components a1 and a2 are formed on an inclined surface, the surface of the notches 10 has very little unevenness. That is, when concrete is poured into the formwork in manufacturing the culvert components a1 and a2, the bubbles in the concrete move upward along the slope in the notch 10, and the hardened notch 10
There is no stagnation on the surface portion. For this reason, after curing, the notch 10 has almost no unevenness, and the adhesion to the flexible joint material 10 is extremely improved. Therefore, the waterproofness between the flexible joint member 10 and the mounting portion 4b can be improved. Further, since the flexible portion 4a of the flexible joint member 4 is curved in a convex shape toward the outside, resistance to deformation from external water pressure is improved. That is, when water pressure from the outside is applied to the flexible portion 4a, since the convex curved surface resists the water pressure, the flexible portion 4a is not deformed until the water pressure becomes higher than that of the concave curved surface. Therefore, even if the water pressure in the soil increases, water does not easily enter from the flexible joint structure K, and the water stopping performance can be improved also in this portion. As a result, the waterproofness of the flexible joint structure K is significantly improved.

The box culvert A thus manufactured in the factory including the flexible joint structure K can eliminate the need for the on-site work of the flexible joint structure K.
This can greatly contribute to quick and simplified construction work on site. Further, as described above, box culverts A, the Calvert components a1 is Bo in a construction site <br/> Tsu box culvert B and, also Calvert component a2 Gabo
After being connected to the x-culvert C, respectively , the outer connecting fitting 5 is removed, and the original flexibility is exhibited at the connecting portion between the culvert-constituting portion a1 and the culvert-constituting portion a2. In other words, in FIG. 5, box culvert B and culvert due to uneven settlement or earthquake
In the case where the ground on which the g component part a1 is mounted and the ground on which the box culvert C and the culvert configuration part a2 are mounted have different displacements, the axial directions indicated by arrows α, β, and γ in FIG. , Box culvert B and culvert component a1, box culvert C in the shear direction and the bending direction
And the culvert constituent part a2 moves. That is, the box culvert B and the culvert component a
1, a box culvert C and a culvert constructor a2
If the bets are displaced, it is compressed flexible portion 4a of the flexible joint material 4 box culvert A absorbs collision with Calvert components a1 and Calvert component a2, box culverts A, B, C of damage It is to prevent.
Similarly, when the displacement in the direction of the arrow β occurs, the flexible joint member 4 is deformed so as to extend from the previous state according to the displacement. The joint member 4 is compressed on one side and expanded and deformed on the other side, and the box culverts B and C are moved in the respective directions of displacement so that the box culverts A and
B and C are prevented from being damaged.

In such a deformation of the flexible joint member 4, the filled EPDM sponge rubber 16, 17
And so on do not hinder the function of the flexible joint structure K because they are more easily deformed than the flexible joint material 4. Moreover,
The frictional resistance of these materials including the flexible joint material 4 is determined by the culvert structures a1, a of the box culvert A.
2 is smaller than the friction coefficient of the end faces 9a and 9b,
Further, since the flexible joint member 4 is sandwiched between the end faces 9a and 9b, the possibility that the box culvert A itself is damaged can be reduced.

The specific configuration of each section is not limited to the illustrated embodiment. In the above embodiment, the culvert component a1 and the culvert component a2 were connected by the flexible joint member 4 in the factory. However, the connection of the two box culverts by the flexible joint member 4 was performed at the construction site. It may be performed. That is, for a large box culvert, the box culvert is disposed on the site before the connection with the flexible joint structure K, and the flexible joint member 4 is attached to a target portion to form the flexible joint structure K. May be used. In this case, each of the box culverts connected by the flexible joint member 4 is formed of an inclined surface and has a cutout 10 in which an insert nut 11 is embedded, similarly to the culvert components a1 and a2 in the above-described embodiment. Are preferred. The notch 10 may be formed of, for example, a step parallel to the end face to which the box culvert is connected.

In the case of a workable size in a box culvert, a vertical tightening method in which a PC rope is passed through a sheath hole 8 on site instead of using the external connection fitting 5 described in the above embodiment is adopted. It may be implemented in a factory in advance, and temporarily rigidly connected until the culvert component a1 and the culvert component a2 are constructed at the construction site. In this manner, if the PC rope is used for rigid connection, unnecessary parts can be eliminated, and the manufacturing cost can be reduced. In this case, since the flexible portion 4a of the flexible joint member 4 does not protrude inside the box culvert A, there is no obstacle crossing the sheath hole 8 between the culvert component a1 and the culvert component a2. For example, the rope can be passed all at once from the end face 6 side of the culvert component a1 to the end face 7 of the culvert component a2.

Further, in the above embodiment, a box culvert was described as a concrete product, but it may be, for example, a tubular pipe culvert or a concrete block for constructing a groove. Also, other configurations can be variously modified without departing from the spirit of the present invention.

[0025]

The invention according to each claim of the present application is
As described above, since the flexible joint material is inserted between the end faces of the concrete product, even if the concrete product moves in different directions due to uneven settlement or the like,
It functions as a buffer against the movement, can reduce the butt friction resistance of the concrete product, and can reliably prevent the concrete product itself from being damaged. The invention according to claim 1 and claim 2 is
Furthermore, EPD is more easily deformed than flexible joint material
M sponge rubber is provided in the gap inside the flexible part
The flexible part without interfering with the function of the flexible joint structure.
Can be prevented from being hindered by foreign matter.
You.

If the notch is formed by an inclined surface,
It is possible to prevent bubbles in the concrete from concentrating on the notch during the production. As a result, the unevenness on the surface of the notch can be minimized, the adhesion between the notch and the flexible joint material is improved, and the water stopping performance is further improved.
Further, since the flexible portion of the flexible joint material is inserted between the end faces of the concrete product, the deformation resistance to external water pressure can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the invention according to the present application.

FIG. 2 is an exploded perspective view showing a culvert component and a flexible joint material of the embodiment.

FIG. 3 is a front view of a culvert component of the embodiment.

FIG. 4 is a sectional view taken along line II in FIG. 1;

FIG. 5 is an exemplary perspective view showing one use state of the embodiment;

[Explanation of symbols]

 A: Concrete product (box culvert) K: Flexible joint structure a1, a2: Product body (culvert constituent part) 4: Flexible joint material 4a: Flexible part 4b: Mounting part 5: External connection fittings 9a, 9b ... End face 10: Notch

Claims (4)

(57) [Claims] 1. A flexible material is provided between two opposing end faces of two concrete products arranged substantially on the same straight line so that one concrete product can be displaced independently of the displacement of the other concrete product. A flexible joint structure for concrete products to be connected to each other, wherein notches are provided at opposite end faces of each of the concrete products, and a flexible portion that deforms the notches of each of the concrete products according to displacement is provided. Bridge with a joint material, insert the flexible part of the flexible joint material between the facing end faces, and
Easily deformable EPDM sponge rubber is applied to the gap inside the flexible part.
A flexible joint structure for a concrete product , provided between the flexible joints. 2. The flexible joint structure for a concrete product according to claim 1, wherein the cutout portion has an inclined surface inclined toward the rear of the end surface. 3. A two-piece product body of the same shape having a notch at one end face in the connecting direction, and a flexible portion having a deformable portion which is deformed in accordance with the displacement of the product body, wherein the notches are arranged to face each other. A flexible joint material for bridging by inserting both cutouts of the product main body between both end surfaces, and a temporary joint for temporarily connecting the respective product main bodies bridged by the flexible joint material. A concrete product having a flexible joint structure, comprising: a stopping member. 4. The concrete product having a flexible joint structure according to claim 3, wherein the cutout portion has an inclined surface inclined toward the rear of the end face.