JPS6242094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of burying and fixing an insert for attaching a step to a manhole side wall mass of a manhole, and a method for embedding and fixing the insert safely, reliably, and firmly. This invention relates to a method for embedding and fixing an insert for installing a step in a manhole with the aim of improving workability.

Generally, a step is fixed to the inner wall of this type of manhole to allow workers to enter and exit, but conventional steps have two methods: one is to embed the step integrally when the manhole is formed, and the other is to pierce the manhole wall after forming. Two methods are known: one is to install the step later in the hole.

First of all, the former method does not pose any safety problems, but the formwork where the steps are attached is fine, it takes a lot of time to assemble, and it causes vibration when compacting the concrete, so the formwork cannot be connected properly. This makes it easy for parts to become misaligned, and the skin of the molded product will show tromole and marks of misalignment (misalignment) at the joints of the molds, resulting in an unsightly appearance.

The latter is a method devised to solve the appearance and workability of the former, but this method involves drilling a through hole in the manhole wall with a diameter that is approximately larger than the diameter of the step leg, and After directly inserting the leg of the step, bolts and nuts were tightened from the outside of the manhole, and a filling material such as mortar was inserted around the tightened portion.

In this method, the diameter of the through hole is larger than the diameter of the leg of the step, so the entire step becomes unstable and is insufficient in terms of stable maintenance.The outer filling material is prone to cracking, and the inside and outside of the manhole is Water leaks occurred, which induced harmful acidification, which posed the risk of the steps corroding and breaking out.

As described above, the conventional methods have various drawbacks in terms of safety, reliability, robustness, and workability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for embedding and fixing an insert for installing a step in a manhole, which eliminates the drawbacks of the above-mentioned conventional methods.

Next, an embodiment of the present invention will be described with reference to the drawings. First, a mold for forming manholes 16a and 16b is formed by an inner frame 1 and an outer frame 19', and small holes 2 are bored in predetermined positions of this inner frame 1. A central hole 4 is formed approximately at the center of the reinforcing member 3 in a penetrating shape. Here, in the first basic step, the small hole 2 of the inner frame 1 and the center hole 4 of the reinforcing member 3 are positioned so as to be in communication with each other, and the reinforcing member 3 is fixed to the surface 1a of the inner frame 1 by means such as welding. do.

Although only one reinforcing member 3 is shown in the embodiments shown in FIG. Therefore, a pair of reinforcing members 3 is also required, but only one of them is shown in the drawing for convenience. Also, a pair of insert members 12, 12
If the insert members are connected to each other by a flat bar 24, the insert members can be held more stably during concrete formation.

Next, in the insertion process, the large diameter part 6 of the insertion member 5 is inserted and tightly fitted into the central hole 4 of the reinforcing member 3,
The tip shaft 8 of the insert member 5 is positioned inside the formwork via the central hole 4 and the small hole 2. Here, the insert member 5 includes a large diameter portion 6 having a diameter that can be tightly fitted into the central hole 4, and an insert member 12 located in front of the large diameter portion and having a smaller diameter than the large diameter portion. It consists of a small diameter part 7 having a diameter that is approximately equal to or smaller than the inner diameter of the inner diameter, and a tip shaft 8 located in front of the small diameter part and having a smaller diameter than the small diameter part. A male threaded portion 9 is formed. Further, an insert member 5 is provided on the front side of the large diameter portion and protrudes from the reinforcing member 3.
It is a good idea to attach a nut 10, etc., which is convenient when turning with a spanner or the like. Further, a washer 11 is inserted between the reinforcing member 3 and the insert member 5.

Next, since a male screw part 9 is formed at the tip of the tip shaft 8 of the insert member 5 positioned inside the formwork in the above insertion process, the rear end of the cylindrical insert member 12 is formed in the temporary fixing process. bottom 1
The male threaded portion 9 of the tip shaft 8 is inserted into the through hole 14 formed in 3.
is inserted from the inside of the insert member 12 toward the outside, and the nut 17 is screwed into the male threaded portion 9 protruding from the through hole 14 via the washer 15 to place the insert member 12 at a predetermined position inside the formwork. Keep it stable. That is, the insert member 12 is the nut 1
7 and the side wall 18 of the large diameter portion 6 of the insert member 5, and the washer 15 is provided to prevent concrete from flowing into the insert member 12 from the through hole 14.

In this state, the formwork is filled with concrete, and after this concrete has solidified, the nut 10 that is integrated with the insert member 5 is rotated with a spanner or the like.
Release the screwed state between the nut 17 and the male threaded part 9, and insert the insertion member into the reinforcing member 3 and the insert member 12.
Pull it apart to complete the drawing process. At this time, the nut 17 and washer 15 are left in the concrete.

Then, the formwork is removed from the completed manholes 16a, 16b to complete the demolding process.

Since the present invention embeds and fixes the insert member in concrete by the above method, Step 19
The leg portion 20 of the insert member 12 is inserted together with a filling material 21 made of mortar, milk cement, etc.
When the step is inserted into the insert member, the retaining plate 23 provided in advance inside the insert member engages with the recessed notch portion of the leg portion 20, preventing the inserted step from coming out from the insert member. A portion of the filler 21 packed without any gaps overflows from the insert member, so the condition of the filler inside the insert member can be confirmed from its appearance, and the legs 20 of the step 19 and the insert member 1
Perfect fixation with 2 is possible. After the leg of the step is inserted into the insert member, the inlet gap between the leg and the insert member may be filled with caulking material 22, if necessary, to further strengthen the bond between the two. Furthermore, an air vent hole (not shown) can be formed inside the insert member 5 if necessary, to prevent the pressure inside the insert member from decreasing during the drawing process and making it difficult to pull out the insert member. The large diameter portion may be tapered to make it easier to pull out the insertion member 5.

As explained in detail above, the method of burying and fixing an insert for installing a step in a manhole according to the present invention allows the insert member to be safely, reliably, and firmly buried in a predetermined position within the manhole side wall mass of the manhole. Workability is also very good, and the step inserted into this insert member is held and fixed in an extremely stable state, so it has excellent effects such as being able to prevent workers from falling accidents.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a manhole equipped with a step according to the present invention, Fig. 2 is a plan view of the step, Fig. 3 A is a front view of the insert member, B is a longitudinal sectional view thereof, and Fig. 4 is the insert member. An explanatory view of the state in which the leg of the step is inserted into the inside, and Fig. 5 shows the nut, washer, insert member, washer,
FIG. 6 is an exploded perspective view of each part of the insertion member, FIG. 6 is a perspective view of the reinforcing member, and FIG. 7 is a cross-sectional view of the state immediately before the drawing process of the present invention. 1...Inner frame, 2...Small hole, 3...Reinforcement member, 4
...Central hole, 5...Insert member, 6...Large diameter part, 7...Small diameter part, 8...Tip shaft, 9...Male thread part, 10, 17...Nut, 11, 15...Washer , 12... Insert member, 13... Rear end bottom of insert member, 14... Through hole, 16
a, 16b...manhole, 18...side wall of large diameter section, 19...step, 20...leg, 21...
Filler, 22...caulking material, 23...retention plate, 24...flat bar.

Claims (1)

[Claims] 1. A basic step of fixing the reinforcing member to the surface of the inner frame by positioning the reinforcing member so that the small hole drilled at a predetermined position in the inner frame communicates with the central hole of the reinforcing member; It consists of a large diameter part with a diameter that can be tightly fitted into the hole, and a diameter that is located in front of the large diameter part and is smaller than the large diameter part, and has a diameter that is approximately the same size or smaller than the inner diameter of the insert member. An insert member having a small diameter portion and a tip shaft located in front of the small diameter portion and having a smaller diameter than the small diameter portion, and a male screw portion is formed at the tip of the tip shaft. an inserting step of inserting and tightly fitting the diameter portion into the center hole, thereby positioning the tip shaft of the insert member inside the formwork via the center hole and the small hole 2; and the bottom of the rear end of the cylindrical insert member. Insert the male threaded part of the tip shaft from the inside to the outside of the insert member into the through hole formed in the hole, and screw the nut into the male threaded part that protrudes from the through hole to insert the insert member inside the formwork. There is a temporary fixing process to stably hold the mold in place, and concrete is filled inside the formwork, and after this concrete has hardened, the threaded state between the nut and the male thread is released, and the inserted member is removed from the reinforcing member and the insert member. A method for burying and fixing inserts for installing manhole steps, which comprises a pulling process of pulling apart and a demolding process of taking out the formwork from the completed manhole.