JPS59220532A - Inlaying fixation of insert for fitting step of manhole - Google Patents

Abstract

PURPOSE:To safely and exactly lay and fix inserts by providing a specific foundation process, an insertion process, a temporary anchoring process, a striking process, a drawing process, and an unmolding process. CONSTITUTION:In the foundation process, the small hole 2 of an outer frame 1 is led to the central hole 4 of a reinforcement 3, and the reinforcement 3 is welded to the surface 1a of the outer frame. In the insertion process, the male screw 7 of an insert 6 is screwed with the female screw 5 of the hole 4, and the tip 6a of the insert 6 is positioned on the inside of the outer frame. In the temporary anchoring process, an insert 8 is put into the tip 6a, the screw 14 of the tip 6a is screwed with the thread 15 of a stopper 9, and the insert 8 is held in place in the inside of the outer frame. In the striking process, concrete is packed into the outer frame, and the coupling between these parts 6 and 3 is released. Under the condition, the stopper 9 is struck to cause cracks 11 to occur between the inside of the manhole and the stopper 9. Lastly, the concrete in the cracked portion is separated, the stopper 9 is drawn out, and the outer frame 1 is removed out.

Description

[Detailed Description of the Invention] The present invention relates to a method of burying and fixing an insert for installing a cough step when the step is installed in a manhole side wall mass of a manhole, and a method for burying and fixing the insert safely, reliably, and firmly. This invention relates to a method for embedding and fixing an insert for attaching a step in a manhole with the aim of improving workability.

Generally, steps are fixed to the inner wall of this type of manhole to allow workers to enter and exit.
Two methods are known: one is to embed the steps integrally during molding of the manhole, and the other is to install the step into a hole penetrated through the manhole wall after molding.

First of all, the former method does not pose any safety problems, but the formwork where the steps are attached is fine and requires a lot of time to assemble, making it difficult to take pictures when compacting the concrete. As a result, the joints of the formwork tend to become misaligned, and the molded product's no-da (skin) traps tumble, and marks of misalignment (misalignment) at the joints of the formwork occur, resulting in a poor 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 approximately larger than the foot diameter of the step. After inserting the step leg directly into the manhole, bolts and nuts are tightened from the outside of the manhole, and this tightening involves inserting a filling material such as mortar around the manhole.

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 There was a risk of water leakage, which induced harmful acidification, which could corrode the steps and lead to leakage.

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

The object of the present invention is to solve the above-mentioned drawbacks of the conventional methods, and to provide a method for burying inserts for installing steps in manholes, which is particularly useful when forming concrete by roll compaction or centrifugal forming using only the outer frame as the formwork. The purpose is to provide a fixing method.

Next, an embodiment of the present invention will be described with reference to drawings. First, an outer frame 1 is formed as a mold for forming manholes 16a and 16b, and small holes 2 are bored at predetermined positions in this outer 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 outer frame 1 and the center hole 4 of the reinforcing member 3 are positioned so that they are in communication, and the reinforcing member 3 is fixed to the surface 1a of the outer frame 1 by means such as welding. do. In the embodiments shown in FIG. 4 and below, the reinforcing member 3
Although only one reinforcing member 8 is shown in the figure, since there are two leg parts 20 in the step 19, a corresponding number of insert members 8 are naturally required. 3.Although a pair is required, only one of them is shown in the drawing for convenience. Further, if the pair of insert members 8, 8 are connected to each other by a flat parr 12, the insert members can be held more stably during concrete formation.

Then, in the insertion process, the male threaded part 7 of the insertion member 6 is screwed into the female threaded part 5 formed on the inner circumferential wall of the central hole 4 of the reinforcing member 3, and the male threaded part 7 is inserted through the central hole 4 and the small hole 2. The tip 6a of the insert member 6 is positioned inside the outer frame. It is preferable to attach a nut or the like to the portion of the insert member 6 that protrudes toward the front side of the reinforcing member 30 so as to conveniently rotate the insert member 6 with a spanner or the like. Further, a washer 13 is inserted between the reinforcing member 3 and the insertion member 6.

At the tip 6a of the insert member 6, which has been pressed into position inside the outer frame in the above-mentioned insertion step, is a locking screw portion 14 (either a male thread or a female thread may be used, and a female thread is shown as an example in the figure).
is formed, the cylindrical insert member 8 is inserted from the tip 6a of the insertion member 6 in the temporary fixing step, and in this state, the plug member 9 is engaged with the engagement screw portion 14 of the tip 6a. The threaded portion 15 is screwed together and the tip opening 8a of the insert member 8 is closed with a plug member 9 to prevent concrete from entering, and the insert member 8 is stably held at a predetermined position inside the outer frame. It is preferable that the tip surface has a rounded shape. In this case, when rolling force from the rolls is applied to the plug member, the pressure can be dispersed, which has the effect of preventing damage to the plug member or the insert member.

After filling the outer frame with concrete in this state, the screwing state between the insert member 6, the plug member 9, and the reinforcing member 3 is released before the concrete completely hardens, and in this state, the insert member 6 or a separate dowel pin is removed. 10, tap the plug member 9 from the inside of the insert member and insert it into the manhole 16.
a, cracks 11 are formed in the concrete between the inside of 16b and the plug member 9 to serve as a mark for specifying the position, and the pounding process is completed.

If the dowel pin 10 is to be used for striking, it is convenient to form a through hole 17 in the center of the insertion member 60 as shown in FIG.

In step b, in the removal step, the concrete in the cracked part is curetted using an appropriate jig to expose the tip of the plug member 9, and the key part 18 provided at the tip of the plug member is used. The plug member is pulled out toward the inside of the manhole 16a16b, and the outer frame 1 is removed from the manhole through a demolding process.

Since the present invention embeds and fixes the insert member in concrete by the method described above, the legs 20 in step 19 are filled with a filling material 22 made of mortar, milk cement, etc.
When the step is inserted into the insert member 8, the removal stop plate 21, which is provided in advance in the insert member, engages with the recessed notch part of the leg portion 20, and the inserted step is prevented from being removed from the insert member. In addition, some of the filler 22 packed tightly into the insert member overflows from the insert member, so you can check its appearance and the condition of the filler inside the insert member, and the condition of the filler 22 in step 19. Perfect fixation between the insert member 8 and the insert member 8 becomes possible.

After the legs of the step are inserted into the insert member, caulking material 23 is filled in the entrance gap between the legs and the insert member as necessary to further strengthen the connection between the two.

Furthermore, a through hole 17 is formed in the insert member 6 according to the required pressure, and this hole is used not only for inserting the dowel pin 10 but also for removing the insert member when the pressure inside the insert member decreases and the insert member is not pulled out. This is provided to prevent this from becoming difficult, and it is also conceivable that the insertion member 6 be tapered to make it easier to pull out.

As explained in detail above, the method of embedding and fixing an insert for installing a step in a manhole according to the present invention allows the insert member to be safely and securely placed at a predetermined position inside the hole side wall of the manhole.
It can be buried securely and firmly, and its workability is extremely good.The step inserted into this insert member is held and fixed in an extremely stable state, which prevents workers from falling. It has excellent effects such as:

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a manhole with a sys-step installed 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 a longitudinal sectional view of the manhole. The figure is an explanatory view of the step leg inserted into the insert member, Figure 5 is an exploded perspective view of the insert member, washer, insertion member, and plug member, Figure 6 is a perspective view of the knock pin, Figure 7 is an exploded perspective view of the insert member, washer, insertion member, and plug member. The figure is a perspective view of the reinforcing member, and FIG. 8 is a cross-sectional view of the reinforcing member in a state immediately before the removal process of the present invention. 1...Outer frame, 1B...Surface, 2...Small hole, 3...
・Reinforcement member, 4...Central hole, 5...Female screw part, 6.
... Insert member, 6a... Tip part, 7... Male screw part, 8... Insert member, 8a... Tip opening,
9... Plug member, 10... Dowel pin, 11... Cracks, 16a, 16b... Manhole patent applicant Yanagisawa Concrete Industries Co., Ltd. Figure 1 Figure 4 Figure 8 9 Figure O 8

Claims (1)

[Scope of Claim] An embedding fixing method in which concrete is filled with concrete by roll compaction or centrifugal force forming, and inserts for locking the legs of steps are buried in the concrete during the filling of the concrete, comprising: A basic step of fixing the cough reinforcement member to the surface of the outer frame by positioning the small hole drilled at a predetermined position and the center hole of the reinforcement member so that it communicates with the center hole of the reinforcement member, and forming the center hole of the reinforcement member on the inner peripheral wall thereof. an insertion step of positioning the tip of the insertion member inside the outer frame via the central hole and the small hole by screwing the male threaded part of the insertion member into the female threaded part; The insert member is inserted through the tip of the insertion member, and a stopper member is screwed onto the tip, thereby closing the tip opening of the insert member and stably holding the insert member at a predetermined position inside the outer frame. After filling the inside of the outer frame with concrete, the insert member and the plug member and the reinforcing member are unthreaded before the concrete is completely solidified, and in this state, the insert member or a separate dowel pin is removed. A tapping step in which the plug member is pounded against the inside of the insert member using a screwdriver to form a crack in the concrete between the inside of the manhole and the plug member, and a concrete IJ-t in the cracked portion is curetted to peek into the plug member. A method for embedding and fixing an insert for installing a step in a manhole, which comprises a removal step of pulling out the plug member toward the inside of the manhole, and a demolding step of removing the outer frame from the completed manhole.