JP3870285B2 - Shaft construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaft used for the construction work of a sewer classified as a small shaft by the Japan Sewerage Pipe Promotion Technology Association, and a construction method for a sewer manhole, a pump room manhole, and the like.
[0002]
[Conventional branching]
Conventionally, as a method for constructing a small shaft, there are a steel method shown in FIG. 1, a concrete block settlement construction method shown in FIG. 2, a concrete block rotary press-fitting method shown in FIG.
[0003]
In the steel method, while the steel casing a is pushed in by rocking or rotational press-fitting, the earth and sand in the casing is excavated and discharged using a telescopic clamshell b or a dedicated excavator, and excavated to a predetermined depth. After completion, the concrete is placed in the bottom board and then the concrete manhole is installed in the steel casing. However, since the steel casing is left behind, there is a problem that it requires a corresponding amount of cost.
[0004]
The concrete block subsidence construction method installs a concrete block d with a steel blade c attached to the tip, and digs in the block with a telescopic clamshell b while subsiding with its own weight and press-fitting device e. The steel reinforcement band wound around the block end is connected by welding, and the block is subsidized to the specified depth while adding the block, and the bottom concrete is placed to stabilize the bottom plate, and the shaft is completed However, there are problems with construction speed and welded joint method.
[0005]
The concrete block rotary press-fitting method uses a telescopic clam shell to push the earth and sand in the block while pushing the cylindrical precast concrete block g with the blade casing (steel) f connected to the tip using a rotary press-fitting machine h. It is a method of excavating and earthing using the block, press-fitting to a predetermined depth while connecting the block by welding, and then placing the bottom concrete to complete the bottom for stabilization, but the block requires strength There is a problem that the tube thickness must be increased and a problem that the structure of the connecting portion of the block must be made strong.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention firstly is a construction method that does not leave a steel casing as in the steel system, and therefore can be reduced in construction cost, and secondly, the construction speed is faster than the concrete block settlement construction system. And, the block connection structure is simple, and thirdly, the block connection structure is simpler than the concrete block rotary press-fitting method, and the pipe thickness is the minimum necessary to withstand earth pressure. Another object of the present invention is to provide a construction method that facilitates the position control of the sewer pipe connection port.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems, and the first invention is that a steel casing is inserted inside the shaft building block, and the outer diameter is lower than the outer diameter of the shaft building block at the lower end thereof. After installing a large blade, set the upper part of the steel casing in a rotary press for vertical shaft excavation, digging in while applying rotational pressure, press-fitting into the ground, and sinking the vertical building block to the specified position This is a vertical shaft construction method characterized by pulling out a steel casing. According to this method, a vertical shaft can be constructed at a construction speed equal to or higher than the conventional concrete block rotary press-fitting method. Since no rotational force is directly applied to the block, the pipe thickness can be made thinner than in the case of the concrete block rotary press-fitting method. There is an advantage that it is unnecessary and may be simple.
[0008]
The second invention according to claim 2 is a shaft construction construction method characterized in that the shaft construction block and the steel casing are temporarily fixed by connecting or linking means until the construction is established to a predetermined position. And, by providing a mark on the inner surface of the steel casing corresponding to the planned sewer connection port of the shaft building block, for example, by providing a connector, the steel casing is rotated and positioned while looking at the mark. If it does so, the effect excellent in the sewer pipe connection construction that the position of a sewer pipe connection port can be easily positioned in a predetermined position is acquired.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the examples shown in the drawings.
[0010]
FIG. 4 is a longitudinal sectional view of a first embodiment of the present invention, in which 1 is a cylindrical concrete shaft building block, 2 is a steel unit casing, 3 is a blade edge, and 4 is a rotary press-fitting machine for shaft excavation. It is.
[0011]
In this embodiment, first, the cutting edge 3 is fixed by fastener 5 to the lower end of the first unit casing 2 (FIG. 4, the lowermost unit casing 2), fitting the pit building block 1 of each stage to the outside To do.
[0012]
The outer diameter of the blade edge 3 is larger than the outer diameter of the shaft building block 1, and the rotary press machine 4 is provided with a chuck cap 6 that can be connected to the unit casing 2 so as to cover the shaft building block 1, Connected to the unit casing 2.
[0013]
The cap 6 is chucked to the gripping device 4a of the rotary press-fitting machine 4, and is dug while applying the rotary pressure input through the cap 6, and press-fitted into the ground. The rotational pressure input is transmitted in the order of cap 6 → unit casing 2 → blade 3. On the other hand, the shaft construction block 1 has a structure in which no rotational force is transmitted and only pressure input is transmitted, and a plug-in joint system can be employed.
[0014]
As the unit casing 2 rotates, the shaft building block 1 also rotates. Although not shown in the figure, a lubricant is inserted between the unit casing 2 and the shaft building block 1, or the shaft building block 1 is disposed on the outer periphery of the unit casing 2. It is preferable to mount a rotating roller in order to secure a clearance between the rotating roller and the load.
[0015]
If it is press-fitted to a predetermined depth, the unit casing 2 and the shaft building block 1 are press-fitted while being added, and after the predetermined number of press-fits are finished, the bottom base concrete is placed in the cutting edge part, and after hardening, The unit casing 2 set inside is collected.
[0016]
The shaft thus completed has no flaws on the inner surface of the concrete shaft 1 (in the case of the conventional construction method, the inner surface of the concrete block is damaged during excavation), and the finish is also beautiful. Since the structure of the concrete shaft construction block does not generate a load of rotational force, the function for transmission of the rotational force (welding, bolt connection) is not required, and a slip-out prevention function, for example, a locking pin 7 as shown in the figure is added. If it does, the technique of the joint part between the plug-in type sewer which has a water stop performance and a seismic performance can be applied.
[0017]
When the inner diameter of the shaft is about 900 mm to 3000 mm, a concrete block = concrete pipe is appropriate, and when it is 900 mm or less, for example, it is possible to construct using a PVC pipe.
[0018]
FIG. 5 is a longitudinal sectional view of the second embodiment of the present invention. The major difference between this embodiment and the first embodiment is that the shaft building block 1 and the unit casing 2 are connected to each other at the time of rotary press-fitting. It is the point which was made to rotate integrally.
[0019]
In this embodiment, the shaft building block 1 and the unit casing 2 are integrated by anchor bolts 9 and nuts 10 which are attached to a steel band 8 wound around the outer periphery of the shaft building block 1 and are exposed on the inner surface of the block. ing. Moreover, each unit casing 2 is made into a divided structure, the mutual connection is performed by the expansion bolts 11, and the unit casing 2 is brought into close contact with the inner surface of the shaft building block 1.
[0020]
Therefore, the construction procedure of the second embodiment is performed according to the work procedure of the first embodiment, and a detailed description thereof is omitted here.
[0021]
Compared to the first embodiment, the second embodiment requires extra work for integrating the shaft building block 1 and the unit casing 2 and removing it, but in actual work, an electric nut rotating tool is used. Because it is used, there is no burden on the work.
[0022]
The great advantage of this integrated system is that the position of the planned hole 13 for connecting the sewer pipe 12 can be easily positioned at the time of construction. For example, in the case of the embodiment of FIG. 5, if the nut 10 for stopping the anchor bolt 9 is positioned in advance at the position of the planned hole 13, the nut 10 is used as a mark and positioned by the rotary press-fitting machine 4. Positioning work can be easily performed.
[0023]
Here, although the case where the concrete shaft construction block was used was described, it is needless to say that the case where a synthetic resin shaft construction block is used can also be applied.
[0024]
In the second embodiment shown in FIG. 5, anchor bolts 9 and nuts 10 are used as connecting means between the shaft building block and the steel casing, but as shown in FIG. 6, a packing material 14 such as rubber is attached to the tip. The push bolt 15 may be connected to the steel casing 2 and connected as shown in FIG. 7 or may be a spline joint type connecting means 16, and the connecting or connecting means may be arbitrarily selected.
[0025]
【The invention's effect】
As is apparent from the above description, according to the present invention, the following effects can be obtained.
(1) In the construction method of shafts by the Nakabori method using concrete blocks, the concrete blocks are damaged by giving the steel casing set in the concrete blocks the transmission of rotation and pressure input to the ground. Large rotational pressure input can be provided.
(2) The concrete block can simplify the joint structure (plug-in joint) and reduce the tube thickness compared to the conventional block.
(3) According to the second invention, since the concrete blocks are respectively connected to the steel casing, the rotational force is distributed and the load is small. In addition, positioning of the planned sewer pipe connection hole becomes easy.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a conventional steel method.
FIG. 2 is an explanatory diagram of a conventional concrete block settlement construction method.
FIG. 3 is an explanatory diagram of a conventional concrete block rotary press-fitting method.
FIG. 4 is a longitudinal sectional view of a first embodiment of the present invention.
FIG. 5 is a longitudinal sectional view of a second embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of a third embodiment of the present invention.
FIG. 7 is a longitudinal sectional view of a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft construction block 2 Unit casing 3 Cutting edge 4 Rotary press-fit machine 5 Fastening tool 6 Cap 7 Locking pin 8 Steel band 9 Anchor bolt 10 Nut 11 Expansion bolt

Claims (2)

  Insert a steel casing inside the shaft building block, attach a cutting edge larger than the outside diameter of the shaft building block to the lower end, and set the upper part of the steel casing to the rotary press for shaft excavation Then, the shaft construction method is characterized in that it is excavated while being subjected to rotational pressure input, and is inserted into the ground, the shaft construction block is set up to a predetermined position, and then the steel casing is pulled out. 2. The shaft sunk construction method according to claim 1, wherein the shaft construction block and the steel casing are temporarily fixed by connecting or linking means until they are sunk to a predetermined position.

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