JPH0243851B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for constructing a prefabricated manhole constructed by stacking a plurality of concrete blocks such as frame blocks, straight wall blocks, and slant wall blocks. It is.

[Prior Art] This type of manhole is constructed by, for example, placing a chestnut foundation or the like at the bottom of excavated ground, laying a bottom slab block on this foundation, and placing a column block or a straight wall block on top of the bottom slab block. It is generally constructed by stacking a plurality of concrete blocks, such as sloping wall blocks, and then backfilled with soil around the blocks for use.

However, recent backfilling work is carried out using heavy equipment such as bulldozers, so that uneven earth pressure tends to act on the stacked blocks during the work. Therefore,
If the blocks are not firmly joined together, there is a problem in that the blocks may become misaligned during backfilling.

In order to solve this problem, we can wrap a strip around the joints of vertically adjacent blocks,
Alternatively, a method has been proposed in which a connecting plate is attached to the outer periphery of the upper block to the lower block to directly connect each block to prevent misalignment between the blocks. However, when the upper and lower blocks are joined by such a method, misalignment is likely to occur between the two blocks when they are stacked up. As a result, problems arise in that both blocks are joined while their relative positions remain misaligned, and that it becomes difficult to attach the connecting plate, etc., and that it takes time and effort to correct the positions of the blocks.

In addition, with such a device, it is necessary to thread the bolt into the nut and tighten it on site, which also makes the work complicated.

In addition, when using these methods, each block must be connected from the outside during installation, so additional ground must be excavated to provide space for the connection work, and
Since it is necessary to set up scaffolding for the connection work outside the blocks, construction is time-consuming, and there is also the disadvantage that there is a risk of disaster if the side soil collapses during the work.

[Problems to be Solved by the Invention] Among the above-mentioned inconveniences, the present invention particularly solves the inconvenience of complicating work due to bolt tightening, and the misalignment of blocks that occurs when blocks are stacked together. Problems caused by this, such as circumferential misalignment between blocks remaining in the completed manhole, and the need to correct the misalignment of blocks before tightening the joint, adversely affecting the efficiency of construction work. The aim is to easily and reliably solve the problem of

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention constructs a manhole by stacking a plurality of concrete blocks such as frame blocks, straight wall blocks, and inclined wall blocks. In this case, a fastener having a shaft portion and a head having a diameter larger than that of the shaft portion is attached to one joint surface of the block whose joint surfaces are butt to be adjacent to each other above and below. The block is erected in such a way that it cannot be removed with a wedge insertion portion left in between, and on the other hand, a box with an end wall with a hole exposed on the joint surface is opened on the circumferential surface of the block. The fastening device is provided with a head portion of the fastening device protruding into the box through the hole by abutting both blocks, and a portion of the fastening device is provided between the head portion of the fastening device and the end wall of the box. A washer with a wedge-shaped cross section and a notch through which the shaft can be inserted is driven in from a direction perpendicular to the axis of the fastener to wedge it, and the two blocks are tightly connected together by the force of the washer. It is characterized by being made to do.

[Function] According to such a means, when stacking blocks, the fixing tool provided upright on one joint surface of the blocks serves as a positioning pin, and the blocks are prevented from shifting. . and,
Since this fastener is standing upright with the wedge insertion portion left, a notch is formed in the wedge insertion portion between the head of the fastener inserted into the box and the end wall of the box. Adjacent blocks can be firmly joined together by a simple operation of wedge-fastening the washer having a wedge-shaped cross section.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

The manhole 1 shown in FIG. 1 is constructed by sequentially stacking a plurality of concrete blocks, namely, a bottom block 2, a frame block 3, a straight wall block 4, and an inclined wall block 5. Specifically, the bottom block 2 is a disc-shaped one laid on a chestnut stone foundation 6 with a mortar layer 7 interposed therebetween, and has an annular joint surface 2a on the outer peripheral edge of its upper surface. At the same time, a protrusion 2b for positioning is provided in an annular shape on the outer peripheral edge of the joint surface 2a. The frame block 3 is a cylindrical body whose lower end is fitted inside the protrusion 2b of the bottom block 2 and whose joint surface 3a on the lower end side is joined to the joint surface 2a of the bottom block 2. A pipe 8 constituting a sewerage system is connected to the required portions of the surrounding wall.
An invert 11 having an inverted arch-shaped groove 9 continuous with the tube 8 is installed at the bottom of the rod block 3. Further, the straight wall block 4 is a cylindrical body placed on the body block 3 with the joint surface 4a on the lower end side abutted against the joint surface 3b on the upper end side of the body block 3. be. Furthermore, the slanted wall block 5 is placed on the straight wall block 4 with its lower end side joint surface 5a abutted against the upper end side joint surface 4b of the straight wall block 4, and its upper end side is abutted against the upper end side joint surface 4b of the straight wall block 4. It is formed into an eccentric cylindrical body having a substantially truncated conical shape. A receiving frame 13 for holding the lid body 12 in an openable and closable manner is placed on the joint surface 5b on the upper end side of the inclined wall block 5 via a concrete adjustment ring 14 and a plurality of adjustment rubbers 15, and the receiving frame bolts It is fixed using 16.

When constructing a manhole by stacking a plurality of blocks 2, 3, 4, and 5 in this way, the following construction method is adopted. That is, on one of the blocks 4 and 5 which are to be adjacent to each other above and below with their joint surfaces facing each other, for example, the straight wall block 4, cap nuts 17 which open at the joint surface 4b are spaced equiangularly apart in the circumferential direction. At the same time, bolts 18, which are fasteners, are screwed into each of these cap nuts 17 in a manner that leaves the wedge insertion portions 20 intact (FIG. 2). The bolt 18 has a cylindrical head 18b with a hexagonal wrench hook 18a at the tip.
and a shaft portion 18c having a diameter smaller than that of the head 18b and having a thread carved on its outer periphery. In addition, iron boxes 1 are installed at three locations corresponding to the respective cap nuts 17 of the other block, that is, the inclined wall block 5.
Bury 9. The box 19 is in the form of a housing that opens on the inner circumferential surface of the inclined wall block 5, and the outer surface of its end wall 19a is exposed on the joint surface 5a of the block 5. And on this end wall 19a,
An oval hole 19b is formed through which the head 18b of the bolt 18 can pass (FIG. 2). In addition, on the outer surface of the other end wall 19c of this box 19,
An anchor 21 for firmly embedding the box 19 in the wall block 4 is fixed by welding or the like. Then, when mounting the inclined wall block 5 on the straight wall block 4 with the joint surfaces 5a and 4b abutted against each other, the head 18b of each bolt 18 is passed through each hole 19b and the corresponding one is inserted. Box 19
Let each protrude inward (Fig. 3). After that,
A wedge insertion portion 2 exists between the head 18b of each bolt 18 and the inner surface of the end wall 19a of the box 19.
Drive washer 22 into position 0. (Figure 4). Washer 22
is a wedge-shaped cross section with a circular outer periphery.
It has a long hole-shaped notch 22a that opens at the outer peripheral edge of the hole. That is, this washer 22 has a tapered shape in which the opening end side of the notch 22a is thinner. Therefore, the opening width w of this notch 22a is determined by the diameter of the shaft 18c of the bolt 18 and the head 1.
8a, so that the wedge insertion portion 20 of the shaft portion 18c can be inserted through this notch portion 22a. Therefore, the washer 2 is made to correspond to the notch 22a and the wedge insertion portion 20.
2 from the direction perpendicular to the axis of the bolt 18, the washer 22 is attached to the bolt 1.
8 and the end wall 19a of the box 19.
The straight wall block 4 and the slanted wall block 5 can be firmly joined by being wedged between the straight wall block 4 and the inner surface. In addition, in this embodiment, the straight wall block 4
The same construction method as described above is also used when stacking the shell block 3 and the shell block 3, and when stacking the shell block 3 and the bottom plate block 2.

In addition, 23 indicates each box 1 after the wedge fixation.
9 is filled with mortar. Also, 24 is
The seal groove 25 provided in an annular manner on the upwardly facing joint surfaces 2a, 3b, 4b is connected to the downwardly facing joint surfaces 3a, 4a, 4b.
This is a protrusion provided in an annular shape on 5a. This protrusion 25 is adapted to fit into the seal groove 24 when the blocks 2, 3, 4, and 5 are joined together.
Then, the bag nut 17 and the box 1
The seal groove 24 and the protrusion 25 are omitted only in the portion where the groove 9 is provided. Further, 26 is a foothold for inspection.

However, according to the construction method described above,
When stacking blocks 2, 3, 4, and 5, the bolt 18 screwed into the nut 17 engages with the hole 19b of the corresponding box 19 and functions as a positioning pin. ,3
4, and 4 and 5 are reliably prevented. Furthermore, after that, adjacent blocks can be firmly joined together simply by driving the washer 22 into the wedge insertion portion 20 and wedge-attaching the blocks. Therefore, after stacking the blocks, there is no need to correct misalignment of the blocks, attach strips and connecting plates to the required locations, and screw bolts into designated nuts. , it is possible to construct manholes efficiently and reliably. Furthermore, there is no need for the operation of rotating and tightening bolts for connection, and from this point as well, the effect that each block can be connected quickly and easily can be obtained. The manhole 1 constructed in this way is
Blocks 2 and 3, 3 and 4, and 4 and 5 will be firmly connected to each other by bolts 18, so the uneven earth pressure generated during backfilling will cause the blocks 2, 3, 4, and 5 to Of course, this also eliminates the possibility of misalignment.

Note that the present invention is not limited to the above embodiments, and the following modifications are possible.

First, the fastening device provided on one block is not limited to a bolt, but for example, as shown in FIGS. 6 and 7, a pin with large diameter heads 27b and 28b provided at the tips of shaft portions 27a and 28a. 27, 28, etc. may be used. The pin 27 is fixed by embedding the proximal end of the shaft portion 27a within the block 4. Further, the pin 28 is
A hole 29 is drilled in the block 4, and the shaft portion 28a is inserted into the hole 29 and fixed with an adhesive such as epoxy resin 30, so that the block 4 is erected and cannot be pulled out.

Furthermore, in the above embodiment, a case was explained in which a fixing device was provided on the lower block of the upper and lower adjacent blocks, and a box was provided on the upper block, but conversely, when a box was provided on the lower block The present invention also includes a device in which a fastening device is provided on the upper block.

Furthermore, the number of locations connected by the fasteners and boxes is not limited to three, but may be two or four or more.

Furthermore, the box is not limited to being made of iron, and the method of fixing it to the block is not limited to burying an anchor. The hole formed in the end wall is not limited to an oval shape and may be circular, but an oval shape facilitates engagement with a fastener such as a bolt.

Further, the shape of the washer is not limited to the above-mentioned shape, and may be, for example, a rectangular washer 31 as shown in FIG. 8.

[Effects of the Invention] Since the present invention has the above-described configuration, it is possible to solve the problem caused by the positional deviation of the blocks that occurs when the blocks are stacked together. The problem is that the efficiency of the construction work is adversely affected as the positional deviation of the block remains or work is required to correct the positional deviation of the block before tightening the joint, and the problem that it takes time and effort to connect each block. Therefore, it is possible to provide a method for constructing a manhole that can easily and reliably solve the problem.

In addition, if the box is opened on the inner peripheral surface of the block as in the above embodiment, the bolt tightening work can be done inside the block, so it is possible to tighten the bolts inside the block. It is possible to eliminate the inconveniences such as the time and effort it takes to set up scaffolding for work and the risk of disasters caused by the soil surveying collapsing during connection work.

[Brief explanation of drawings]

Figures 1 to 5 show an embodiment of the present invention, Figure 1 is a sectional view, Figures 2 to 4 are process explanatory diagrams of block joint tightening work, and Figure 5 is an exploded view showing the main parts. FIG. FIGS. 6 and 7 are partial sectional views showing other embodiments of the fastener according to the present invention. FIG. 8 is a perspective view showing another embodiment of the washer according to the present invention. 1... Manhole, 2... Bottom block, 2a
...joint surface, 3...body block, 3a, 3b...
...joint surface, 4...straight wall block, 4a, 4b...
Joint surface, 5... Slanted wall block, 5a... Joint surface,
6... Chestnut stone foundation, 7... Mortar layer, 8...
Pipe, 9... Groove, 11... Invert, 12... Lid, 13... Receiving frame, 14... Adjustment ring, 15...
... Adjustment rubber, 16 ... Receiving frame bolt, 17 ... Nut (cap nut), 18 ... Fastening tool (bolt), 18
a... Wrench hook, 18b... Head, 18c...
Shaft portion, 19... Box, 19a... End wall, 19
b...hole, 19c...end wall, 20...wedge insertion part,
21... Anchor, 22... Washer, 22a... Notch, 23... Mortar, 24... Seal groove, 2
5... Protrusion, 26... Footrest, 27, 28... Fixture (pin), 27a, 28a... Shaft, 27b,
28b...Head, 29...Hole, 30...Epoxy resin, 31...Washer.

Claims (1)

[Claims] 1. When constructing a manhole by stacking multiple concrete blocks such as wall blocks, straight wall blocks, slanted wall blocks, etc., the joint surfaces of the blocks are butted against each other, and the joint surface of one of the blocks that should be adjacent above and below, A fastener having a shaft portion and a head having a diameter larger than the shaft portion is erected with a wedge insertion portion remaining between the head and the joint surface, and is erected in such a way that it cannot be removed. A box with a hole-equipped end wall exposed on the joint surface is opened on the circumferential surface of the block, and the two blocks are brought together and the head of the fastener is inserted through the hole into the box. A washer having a wedge-shaped cross section and a notch through which the shaft of the fastener can be inserted is made to protrude between the head of the fastener and the end wall of the box and is perpendicular to the axis of the fastener. 1. A method for constructing a manhole, characterized in that the blocks are wedged by driving in the direction of the manhole, thereby tightly connecting the two blocks together.