JP2021001463A - Installation method of pressure proof water proof iron cover - Google Patents

Abstract

To provide an installation method of a pressure proof water proof iron cover in which a height adjustment work is easy in installing a receiving frame in accordance with a road slope and which can secure high pressure proof water proof property.SOLUTION: An installation method of a pressure proof water proof iron cover fixes a cover body and a receiving frame 12 for an underground structure with a bolt. The installation method includes the steps of: installing the receiving frame 12 with a space 40 interposed between itself and an upper face of an underground structure 30 via a height adjuster 20; installing a formwork so as to cover the space 40 from an inner peripheral side and an outer peripheral side; and filling the space 40 with a mortar 70. The step of installing a formwork includes, after the step of filling, a step of installing a gap forming formwork 53 so as to form a gap portion 80 along the whole circumference of an inner peripheral edge of a lower face of the receiving frame 12, and further includes, after the step of filling, a step of filling the gap portion 80 with an elastic sealant 90.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for installing a pressure resistant waterproof iron lid.

A pressure-resistant waterproof iron lid is a type of lid for underground structures. For example, in a sewer manhole, a manhole installed at the confluence of large-diameter pipes, or a large pressure on the lid for underground structures due to increased pressure inside the pipe during heavy rain. It is installed in the upper opening of an underground structure that requires high pressure resistance and waterproofness, such as a manhole. As described above, since the pressure-resistant waterproof iron lid is required to have high pressure-resistant waterproofness, the lid body and the receiving frame are fixed with bolts to ensure the pressure-resistant waterproofness of about 0.2 MPa.

By the way, when the lid for the underground structure is installed on the road, the receiving frame is installed at a space from the upper surface of the underground structure via the height adjuster so that the upper surface of the receiving frame coincides with the road surface. The installation method of filling the space between the lower surface of the receiving frame and the upper surface of the underground structure with mortar is generally performed because it can be easily installed even in a place where the road slope is steep. (See, for example, Patent Documents 1 and 2).

However, when the pressure-resistant waterproof iron lid is installed by such an installation method, it is a different material when a very high internal pressure of about 0.2 MPa, which the pressure-resistant waterproof iron lid can withstand, acts in the underground structure. There is a problem that the contact surface between the receiving frame and the mortar is peeled off to form a gap, and water leaks (overflows) from the gap.
Further, in the pressure-resistant waterproof iron lid, since the lid body and the receiving frame are fixed with bolts as described above, the receiving frame is twisted (deformed) due to the torque when the lid is bolted, and as a result, the receiving frame and the mortar There is also a problem that the contact surface is peeled off and the above-mentioned gap is likely to occur.
Therefore, when installing a pressure-resistant waterproof iron lid that requires a high pressure-resistant waterproof property of about 0.2 MPa, concrete, which is the same material as the underground structure, is separately used without using the above-mentioned height adjuster or mortar. Stacking multiple height adjustment rings made of made or resin concrete, the underground structure and the height adjustment ring, and the height adjustment rings are firmly fixed by applying adhesive or sealing material to the receiving frame. After adjusting the height of the concrete, an adhesive or sealing material must be applied to the entire surface of the contact surface to firmly fix it so that the contact surface between the receiving frame and the height adjustment ring, which are made of different materials, does not peel off. It was a situation that did not happen.

However, adjusting the height of the receiving frame using the height adjusting ring has a problem that it takes more time to adjust the height of the receiving frame as compared with the case of using a height adjuster and a mortar.

Japanese Unexamined Patent Publication No. 4-176916 Japanese Unexamined Patent Publication No. 5-1426

The problem to be solved by the present invention is a method of installing a pressure-resistant waterproof iron lid that makes it easy to adjust the height when installing the receiving frame according to the road gradient and can ensure high pressure-resistant waterproofness. To provide.

One aspect of the present invention is a method of installing a pressure-resistant waterproof iron lid for fixing a lid body for an underground structure and a receiving frame with bolts. This installation method includes a step of installing a receiving frame with a space separated from the upper surface of the underground structure via a height adjuster and a step of installing a formwork so as to cover the space from the inner peripheral side and the outer peripheral side. In the step of installing the mold, the step of filling the space with mortar includes a step of filling the mold so that a gap is formed along the entire inner peripheral edge of the lower surface of the receiving frame after the filling step. , Including a step of installing a form for forming a gap, and further including a step of filling the gap with an elastic sealant after the filling step.

In this way, after the step of filling the mortar, by filling the gaps formed along the entire inner peripheral edge of the lower surface of the receiving frame with the elastic sealing material, the inner peripheral edge of the lower surface of the receiving frame is prone to peeling and gaps. Since the elastic sealant exists at the interface between the mortar and the mortar, even if a high internal pressure acts in the underground structure, the elastic action of the elastic sealant and the lower surface of the receiving frame and the mortar are both affected. Due to the adhesiveness, peeling and gaps are less likely to occur, and high pressure resistance and waterproofness can be ensured. Further, since the void portion is formed at a position visible from the inside of the underground structure, the elastic sealant can be easily filled after the step of filling the mortar. Further, since the receiving frame is installed on the upper surface of the underground structure via the height adjuster, it is easy to adjust the height when installing the receiving frame according to the road slope.

In this installation method, the formwork can include an inner formwork that covers the space from the inner peripheral side and an outer formwork that covers the space from the outer peripheral side. In this case, the inner formwork is for forming a gap. It can be formed integrally with the mold. On the other hand, the inner mold and the mold for forming the gap can be separated.

In this installation method, the elastic sealing material is preferably a silicone-based elastic sealing material. Silicone-based elastic sealant has excellent adhesiveness to both metal (reception frame) and mortar, and also has chemical resistance to sulfuric acid, hydrochloric acid, etc., and has excellent durability in a sewerage environment. Is.

According to the present invention, it is possible to provide a method for installing a pressure-resistant waterproof iron lid that can easily adjust the height when installing the receiving frame according to the road gradient and can ensure high pressure-resistant waterproofness.

An example of a pressure-resistant waterproof iron lid is shown, (a) is a plan view, and (b) is a sectional view taken along the line AA of (a). FIG. 5 is a cross-sectional view of a main part showing a method of installing a pressure-resistant waterproof iron lid according to an embodiment of the present invention.

FIG. 1 shows an example of a pressure-resistant waterproof iron lid.
The pressure-resistant waterproof iron lid 10 is installed in the upper opening of an underground structure that requires high pressure-resistant waterproofness, for example, in a sewer manhole, and the round lid body 11 and the receiving frame 12 are connected by three bolts. It is fixed at 13. Specifically, the lid body 11 and the receiving frame 12 are fixed by tightening the three bolts 13 to the three nuts 14 provided on the receiving frame 12 side, respectively, and the internal pressure is about 0.2 MPa. I try to secure it.
On the other hand, the flange portion 12a of the receiving frame 12 is provided with elliptical through holes 12b for mounting the height adjuster described later at six positions at equal intervals in the circumferential direction.

Next, a method of installing the pressure-resistant waterproof iron lid according to the embodiment of the present invention will be described with reference to FIG.

First, as shown in FIG. 2A, the receiving frame is separated from the upper surface of the underground structure 30 such as a manhole via the height adjuster 20 so that the upper surface of the receiving frame 12 coincides with the road surface. 12 is installed. The upper surface of the underground structure includes not only the upper surface of the main body (framework) of the underground structure but also the upper surface of the height adjusting ring or the like installed on the upper surface of the main body (framework) of the underground structure.
The height adjuster 20 used in this embodiment rises from the upper surface of the underground structure 30 and penetrates the through hole 12b provided in the flange portion 12a of the receiving frame 12 along with the anchor bolt 21 and the anchor bolt 21. It can move up and down while being screwed, and is screwed into the height adjusting member 22 for adjusting the height of the receiving frame 12 by contacting the lower surface of the flange portion 12a of the receiving frame 12 and the anchor bolt 21, and the receiving frame 12 A fixing nut 23 for fixing the receiving frame 12 in contact with the upper surface of the flange portion 12a is provided. However, in the present invention, a known height adjusting tool other than the height adjusting tool 20 can also be used.

Next, as shown in FIG. 2B, the formwork is installed so as to cover the space 40 from the inner peripheral side and the outer peripheral side.
In this embodiment, the formwork includes an inner formwork 51 that covers the space 40 from the inner peripheral side, an outer formwork 52 that covers the space 40 from the outer peripheral side, and the inside of the lower surface of the flange portion 12a of the receiving frame 12 as described later. The inner mold 51 and the gap forming mold 53 are separated from each other, including the gap forming mold 53 for forming the gap 80 (see FIG. 2D) along the entire circumference of the peripheral edge. It is formed. Therefore, in this embodiment, the inner mold 51 and the gap forming mold 53 are installed separately. For example, after the formwork 53 for forming the gap is installed along the entire inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12, the inner formwork 51 is installed so as to cover the space 40 from the inner peripheral side.
On the other hand, the inner mold 51 and the gap forming mold 53 can be integrally formed. In this case, by installing the inner formwork 51 so as to cover the space 40 from the inner peripheral side, the formwork 53 for forming the gap portion is also at a predetermined position (the entire inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12). Will be installed in.
In FIG. 2B, the sealing material 60 is applied to the upper surface of the underground structure 30 in order to improve the watertightness with the mortar 70, but the sealing material 60 does not have to be applied.

After installing the molds (inner mold 51, outer mold 52, and void forming mold 53), the space 40 covered with these molds is filled with mortar 70 as shown in FIG. 2 (c). To do. The space 40 can be filled with the mortar 70 through the through hole 12b to which the height adjuster 20 is not attached. Further, as the mortar 70, a non-shrink mortar or the like, which has been used for adjusting the height of the receiving frame, can be used.

After the mortar 70 has solidified, the formwork (inner formwork 51, outer formwork 52, and void forming formwork 53) is removed. Then, as shown in FIG. 2D, after removing the gap forming form 53, the gap 80 is formed along the entire inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12.

Next, the gap portion 80 is filled with the elastic sealing material 90 as shown in FIG. 2 (e). As the elastic sealing material 90, a silicone-based elastic sealing material, a modified silicone-based elastic sealing material, a urethane-based elastic sealing material, an acrylic-based elastic sealing material, a polysulfide-based elastic sealing material, or the like can be used, but they are also available at low cost. Silicone-based elasticity because it is easy to use, has excellent adhesion to both metals (reception frames) and mortar, has chemical resistance to sulfuric acid, hydrochloric acid, etc., and has excellent durability in a sewer environment. It is preferable to use a sealing material. In the slump test (50 ° C.) based on JIS A 5758, the viscosity does not drip due to the ease of filling and finishing the gap 80 and the adhesiveness to the lower surface of the flange 12a of the receiving frame 12 and the mortar 70. It is preferable to use the elastic sealing material 90 having (0 mm).

As described above, in this embodiment, after the step of filling the mortar 70, the elastic sealing material 90 is filled in the gap portion 80 formed along the entire inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12. As a result, the elastic sealing material 90 is present at the interface between the inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12 and the mortar 70, which is prone to peeling and gaps, so that a high internal pressure acts in the underground structure. Even so, due to the elastic action of the elastic sealing material 90 and the adhesiveness to both the lower surface of the flange portion 12a of the receiving frame 12 and the mortar 70, peeling and gaps are less likely to occur, and high pressure resistance and waterproofness can be ensured. it can. Further, since the gap portion 80 is formed at a position visible from the inside of the underground structure, the elastic sealing material 90 can be easily filled after the step of filling the mortar 70. Further, since the receiving frame 12 is installed on the upper surface of the underground structure 30 via the height adjusting tool 20, it is easy to adjust the height when installing the receiving frame 12 according to the road gradient.

In this embodiment, a round pressure-resistant waterproof iron lid is installed, but a square pressure-resistant waterproof iron lid can also be installed by the same installation method.

Further, in this embodiment, the cross-sectional shape of the gap forming form 53 is a rectangle having a height of 8 mm and a width (depth) of 10 mm, but the cross-sectional shape of the gap forming form 53 is not limited to a rectangle. , For example, it may be oval. However, considering the ease of installing the gap forming formwork 53 and the ease of filling the gap portion 80 with the elastic sealing material 90 after removing the gap portion forming mold 53, the gap portion is considered. It is preferable that the cross-sectional shape of the forming form 53 is substantially rectangular.

Further, if the cross-sectional shape of the formwork 53 for forming the gap is too large, the force for supporting the load of the vehicle passing over the pressure-resistant waterproof iron lid 10 decreases, which may lead to cracking or breakage of the mortar 70. On the other hand, if it is too small, peeling or a gap will occur at the interface between the inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12 and the mortar 70. Therefore, the elastic action of the elastic sealing material 90 filled in the gap portion 80 after removing the gap portion forming formwork 53 and the adhesiveness to both the lower surface of the flange portion 12a of the receiving frame 12 and the mortar 70 are well balanced. From the point of view of exertion, it is preferable that both the height and the width (depth) are about 5 to 15 mm.

A pressure-resistant waterproof iron lid installed by the installation method shown in FIG. 2 (example of the present invention) and a pressure-resistant waterproof iron lid installed without using the void forming formwork 53 in the installation method shown in FIG. 2, that is, Regarding a pressure-resistant waterproof iron lid (comparative example) in which the elastic sealing material 90 does not exist at the interface between the inner peripheral edge of the lower surface of the flange portion 12a of the receiving frame 12 and the mortar 70, and the gap 80 is also filled with the mortar 70. A test was conducted to evaluate the pressure resistance and waterproofness. In this test, an internal pressure tester was used to apply water pressure from the inside of the pressure-resistant waterproof iron lid, and the presence or absence of water leakage was confirmed.

As a result of the test, the pressure-resistant waterproof iron lid of the example of the present invention did not leak even when a water pressure of 0.2 MPa was applied.
On the other hand, in the pressure-resistant waterproof iron lid of the comparative example, water leakage occurred at a water pressure of less than 0.1 MPa.

10 Pressure-resistant waterproof iron lid 11 Lid body 12 Receiving frame 12a Flange part 12b Through hole 13 Bolt 14 Nut 20 Height adjuster 21 Anchor bolt 22 Height adjusting member 23 Fixing nut 30 Underground structure 40 Space 51 Inner form 52 Outer type Frame 53 Formwork for forming voids 60 Sealing material 70 Mortal 80 Voids 90 Elastic sealing material

Claims (3)

It is a method of installing a pressure-resistant waterproof iron lid that fixes the lid body for underground structures and the receiving frame with bolts.
The process of installing the receiving frame with a space from the upper surface of the underground structure via the height adjuster, and
The process of installing the formwork so as to cover the space from the inner peripheral side and the outer peripheral side, and
Including the step of filling the space with mortar.
The step of installing the mold includes a step of installing a mold for forming a gap so that a gap is formed along the entire inner peripheral edge of the lower surface of the receiving frame after the filling step.
A method for installing a pressure-resistant waterproof iron lid, further comprising a step of filling the gap with an elastic sealing material after the filling step. The formwork includes an inner formwork that covers the space from the inner peripheral side and an outer formwork that covers the space from the outer peripheral side.
The method for installing a pressure-resistant waterproof iron lid according to claim 1, wherein the inner formwork is integrally formed with the formwork for forming a gap. The method for installing a pressure-resistant waterproof iron lid according to claim 1 or 2, wherein the elastic sealing material is a silicone-based elastic sealing material.

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