JPH07189267A - Caisson blade skeleton body forming method - Google Patents

Abstract

PURPOSE:To shorten the term of work, and to improve safety and accuracy by independently operating a cutting edge body in the ground apart from the construction of a caisson body and connecting the cutting edge body to the caisson body built on the ground. CONSTITUTION:The underground section of a multistoried building is constructed on an irregular site, on which there are an adjacent building, etc., in an open caisson manner. The lot bodies of four layers are superposed and built successively in a caisson body at that time. A cutting edge body 1 and a first lot body are independently erected respectively in caisson construction first at that time, and these cutting edge body 1 and first lot body are combined and the cutting edge body 1 and the first lot body are unified. A second lot body is constructed on the first lot body while being press- fitted and sunk, and subsequently lot bodies are built while integrally press-fitting and sinking the second lot body and subsequent lot bodies. Lastly, a fourth lot body 2d and subsequent lot bodies are press-fitted and sunk integrally, thus completing the execution of works of a caisson. Press-fit facilities are disposed at a plurality of places on the first lot body, and controlled by various measuring instruments and the press-fit control system of a data processor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a blade end skeleton provided on a skeleton skeleton.

[0002]

2. Description of the Related Art The caisson method is to excavate the ground at the lower end (Hakouchi) of a caisson built on the ground in advance, and when this ground cannot support the weight of the caisson, the caisson will naturally It is based on the basic principle of subsidence, and has been widely adopted in recent years in the construction of bridge foundations, etc. due to the advantages such as a short construction period and a small number of personnel.

Recently, in the open caisson method, a method has been developed in which a caisson is press-fitted from the upper side by a combination of a hydraulic jack and an earth anchor, whereby the posture and sinking speed of the caisson body can be controlled by an external force. Became.

Further, techniques for measuring various parameters relating to the posture and condition of the caisson and the resistance of soil have been developed. In addition, the informationized press-fitting management technology that processes the measurement data and feeds back the processed results appropriately and promptly to the excavation work of the natural ground and the press-fitting and submergence work of the caisson is showing rapid progress.

Due to the development of the technology in each field as described above, it is rare when building a large building such as a high-rise building on an irregular site surrounded by buildings and subways in the urban area recently. There is an increasing tendency to construct the underground part using the open caisson method in order to construct it in a short construction period with cost and personnel.

[0006] In the open caisson method, a blade-type blade opening skeleton is provided at the lower end of the peripheral wall of the caisson skeleton. This blade skeleton body has two functions. That is, firstly, when excavating the inside of the box, it is necessary to support the load of the caisson skeleton so that the caisson skeleton does not drop unexpectedly. By leaving it, part of the load of the caisson body is supported by the blade body.

Secondly, since the blade skeleton body has a blade-shaped shape, when the caisson skeleton body is press-fitted and submerged, the blade skeleton skeleton body functions as a cutting edge for cutting down the soil around the caisson skeleton body, and the caisson body sunk Is carried out smoothly and in a short time.

Conventionally, for example, as shown in FIG. 27, a caisson blade skeleton body 1 is constructed as follows together with a beam 7 at the lowermost end of a caisson body 2. First, the ground 8
The waste concrete 3 for supporting the blade skeleton body 1 is placed on the surface GL of.

Next, a scaffold is assembled to assemble a form 4 for integrally forming the blade body 1 and the caisson body 2. At this time, a supporting structure 5 for supporting the caisson frame 2 portion of the form 4 from below is installed.

Then, the reinforcing bar is assembled in the form 4 and the concrete is poured to construct the blade skeleton skeleton 1 and the caisson skeleton 2 integrally. At this time, a blade metal fitting 6 is attached to the tip of the blade skeleton body 1.

After the blade skeleton body 1 and the lowermost portion of the caisson skeleton body 2 are constructed integrally as described above, the supporting work 5 is removed. Then, after excavating the natural ground 8 while leaving the soil around the blade opening body 1 in place, the caisson body 2 is hydraulically pressed from above to collapse the soil around the blade opening body 1 to collapse the blade opening body 1. And, the caisson frame 2 was integrally sunk.

[0012]

However, in the above-mentioned conventional construction method, it takes a lot of time to install and remove the support work 5, which is an obstacle to shortening the construction period. Moreover, since it is not possible to remove all the supporting members 5 together, the load on the cutting edge hardware 6 of the blade skeleton body 1 becomes uneven,
As a result, differential settlement of the caisson skeleton 2 occurred, which was a safety issue.

Therefore, there is a problem to be solved in a caisson blade skeleton body that satisfies both the requirements of shortening the construction period and safety construction.

[0014]

In order to solve the above-mentioned problems, the caisson blade body according to the present invention is provided at the lower end of the peripheral wall of the caisson body, and is a blade-shaped body body. , Independently of the construction of the caisson skeleton, it is constructed in advance in the ground where the caisson skeleton is sunk, and later,
It is configured to be connected to the caisson body constructed on the ground.

The blade skeleton body is constructed by using an off-the-shelf product which is preliminarily integrated with an iron plate and precast concrete. Then, the blade skeleton body is formed by in-situ casting, and at this time, the blade tip metal piece is reinforced with an iron plate and is also used as a mold. Further, a friction cutting member is provided at the tip of the blade body.

[0016]

With the above construction, the portion corresponding to the caisson blade skeleton body of the ground where the caisson skeleton body is to be laid is excavated in advance, and the caisson blade skeleton body is arranged in the excavated ground. On the other hand, the caisson frame is supported on the ground and constructed on the ground. In other words, the blade body and the caisson body are constructed independently of each other, and are later connected and integrated.

As described above, since the blade body is constructed in advance in the ground independently of the caisson body, while the caisson body is constructed by being supported on the ground, the supporting work 5 in the prior art is unnecessary. Become. As a result, the man and time for assembling and removing the support work 5 are saved, the construction period is shortened, and there is no fear of differential settlement when press-fitting, and safety is improved.

Further, since the blade opening skeleton is constructed independently of the caisson skeleton, it is manufactured integrally with an iron plate and precast concrete at a factory or the like, and is placed at a corresponding position of the ground previously excavated beforehand. It may be transported and installed,
Alternatively, it may be constructed by concrete pouring.

In the case of in-situ casting, the cutting edge hardware is reinforced with an iron plate and is also used as a form, so that both material and labor costs are reduced. Further, by providing the friction cutting member at the tip of the blade tip body, friction with the surrounding soil is reduced, and the caisson body is smoothly press-fitted.

[0020]

EXAMPLES Examples of caisson construction using the caisson blade body according to the present invention will be described below with reference to FIGS. In this embodiment, as shown in FIG. 1, a high-rise building, for example, an underground portion of a building with 10 floors above ground is constructed by an open caisson on an irregular site surrounded by adjacent buildings, roads and subways. .

This open caisson is a caisson body 2
And a blade-type blade mouthpiece body 1 provided at the lower end of the peripheral wall of the caisson body 2. The caisson body 2 is a four-layer lot,
That is, from the bottom, the first lot body 2a and the second lot body 2
b, the third lot skeleton 2c, and the fourth lot skeleton 2d are sequentially stacked and constructed.

The height of the first lot body 2a is about 5.5 meters and the weight thereof is about 4000 tons.
Corresponds to the third basement level, its height is about 5.4 meters, its weight is about 2500 tons, and the third lot skeleton 2c corresponds to the second basement, its height is about 5.4 meters, It weighs about 2000 tons, and the fourth lot body 2d is underground 1
Equivalent to a floor, its height is about 5.3 meters and its weight is about 1
It is 800 tons.

The caisson construction consists of building each lot body,
An efficient method is used in which press-fitting and deposition below the lot skeleton immediately below the lot skeleton is performed in parallel.

That is, first, the blade skeleton body 1 and the first lot body 2
build a and a respectively independently, and connect them. And
The second lot skeleton 2 is placed on the first lot skeleton 2a while press-fitting the blade skeleton skeleton 1 and the first lot skeleton 2a as one body.
build b.

Next, the third lot skeleton 2 is constructed after the third lot skeleton 2c is constructed on the second lot skeleton 2b while press-fitting and depositing the skeletons of the second lot skeleton 2b and below as one body.
The fourth lot skeleton 2d is constructed on the third lot skeleton 2c while press-fitting and substituting c and below as one body.

Finally, the caisson construction is completed by press-fitting and digging together the fourth lot skeletons 2d and below.

For the press-fitting, the well-known press-fitting equipment consisting of a combination of the ground anchor 9 and the hydraulic jack 10 is used as the first.
The lots are provided at a plurality of positions on the skeleton 2a, and the operations of these press-fitting facilities are controlled by a press-fitting control system that is informed by various measuring instruments and data processing devices.

In the caisson method, in order to safely, smoothly and efficiently deposit an underground skeleton on a site, it is important to survey the site. According to the results of the geological survey of the site of the present embodiment, the soil quality is, for example, as shown in the geological column diagram in FIG. 7, about 2.30 meters of buried soil and about 5.70 meters of loam layer from the top. , Pseudo ash silt is about 7.60 meters, clay is about 9.80 meters, clay silt is about 10.60 meters, silty fine sand is about 1
2.05m, fine sand about 13.10m, medium sand about 14.50m, silt mixed fine sand about 15.
50 meters, about 17.30 meters of fine sand mixed with shells, about 18.60 meters of silt, about 20.3 of fine sand
0 meters, sandy silt about 19.30 meters, fine sand about 20.30 meters, sand mixed silt about 23.4
0 m, sand mixed sand is about 24.50 m, and gravel is about 30.55 m. A great change in the depth direction can be seen in the N value of these soils, shear resistance angle, adhesive strength, etc. It is one of the factors that make it difficult to control excavation and caisson deposition.

The flow of the whole construction from the caisson construction preparation to the construction completion will be described below item by item. 1. Installation of foundation piles and earth anchors (see FIGS. 2, 4, and 5) First, dozens of foundation piles are driven to the depth of the support layer by the earth drill method or the like. This foundation pile will be connected to the first lot body 2a when the underground construction is completed by the caisson method.

Next, a plurality of ground anchors 9 are installed at a plurality of predetermined positions. The earth anchor 9 is an anchor body made of concrete that is fixed and fixed to the bottom of a hole drilled to the optimum depth for sinking the caisson.
The tension member pulls the anchor body upward, and the tension member is connected to the hydraulic jack 10 later.

2. Manufacture of blade base 1 and preliminary excavation of the ground (see FIGS. 8 to 10) Almost in parallel with the installation of ground anchors 9 and the like, the blade base 1 is buried at the position corresponding to the blade base 1 of the ground 8. Hole 8 for
A is excavated in advance. At this time, already in factories,
As shown in FIG. 8, with precast concrete 1a,
The blade skeleton body 1 including the iron plate 1b and the cavity 1c is manufactured and prepared.

Since the blade skeleton body 1 is integrally formed of the precast concrete 1a and the iron plate 1b, it has a sufficiently large pressure resistance. Further, the blade skeleton body 1 is light in weight because the iron plate 1b is thin and the cavity 1c is formed on the iron plate 1b, and is made convenient for the work such as transportation on site.

The inner surface of the precast concrete 1a is uneven. Due to the unevenness, when concrete is poured into the cavity 1c at the site and integrated with the first lot skeleton 2a, the bonding force between the two is increased.

Further, the cutting edge of the blade skeleton body 1 has a friction cutting 18
Is provided. This is to reduce the friction between the peripheral surface of the caisson body and the surrounding soil as much as possible when the caisson body 2 is submerged, and to make the deposition smooth.

3. Arrangement of the blade end frame 1 The ready-made blade end frame 1 is transported to the construction site at the start of excavation of the hole 8a and is already prepared. Therefore, the blade skeleton body 1 is arranged in the excavated hole 8a as shown in FIG.

4. Construction of the first lot skeleton 2a (see FIGS. 1 to 6) The construction of the first lot skeleton 2a is carried out independently of the construction of the blade skeleton skeleton 1. The construction work is carried out by being supported by the ground GL of the ground 8, and the rebar assembly, formwork formation, skeleton concrete placement, curing, first lot skeleton 2a
Completion, dismantling the formwork and scaffolding.

In this case, the first lot skeleton 2a is the ground 8
Since it is supported by, the supporting work is unnecessary and the stability is good, so the construction period is shortened and the safety is high compared with the conventional one.

The first lot skeleton 2a includes a plurality of pillars 2e which are erected at appropriate intervals along the periphery of the caisson skeleton 2.
A peripheral wall 2f including these pillars 2e and a plurality of beams 2g provided so as to appropriately connect the two pillars 2e horizontally are integrally configured. A plurality of openings 12 are formed between the adjacent beams 2g.

3. Connection between the blade mouth skeleton 1 and the first lot skeleton 2a (see FIG. 10) When concrete is poured into the first lot skeleton 2a, concrete is poured into the cavity portion 1c of the blade skeleton skeleton 1 and, as shown in FIG. The mouthpiece 1 and the first lot body 2a are integrated.

4. Installation of press fitting equipment and crane (Fig. 1-
(Refer to FIG. 6) The tower crane 1 is placed on the completed first lot body 2a.
Install 4. Then, the opening 12 of the first lot body 2a
The pressure girder 11 is installed so as to straddle. Further, the hydraulic jack 10 is installed on the pressure girder 11, and the hydraulic jack 1
0 and the upper end of the tension member of the ground anchor 9 are connected.

In this way, by pulling the tension member of the earth anchor 9 with the hydraulic jack 10, the pressure of the hydraulic jack 10 can be applied downward to the presser girder 11. In addition, the arrangement position of each hydraulic jack 10 is determined based on the results of the soil investigation.

5. Excavation (see Figure 3) Grab hopper 15 on the ground outside the caisson frame 2
And clamshell 16 are installed, and tower crane 14
Through the opening 12, an excavating device such as a mini backhoe 13 is arranged under the caisson frame 2. Further, the dump truck 17 is arranged at an appropriate position outside the caisson frame 2.

Next, as will be described later, the soil around the blade structure 1 is left according to the slope angle and amount determined according to the soil quality, and the other soil is excavated by using the mini backhoe 13 or the like. To do. This excavated earth and sand is tower crane 14,
It is hung up through the opening 12 by the club hopper 15, etc., loaded on the dump truck 17 and transported to the outside.

6. Press-fitting and sinking the first lot body 2a (Fig. 2
(See FIG. 6) After the excavation is completed, the hydraulic jack 10 is operated to apply downward pressure to the first lot skeleton 2a via the presser girder 11. Then, when the resistance force of the soil remaining around the blade body 1 becomes unable to withstand the pressure input, the blade body 1 and the first body
The lot body 2a and the lot body 2a sink together.

7. Construction of the 2nd, 3rd, and 4th lot skeletons and deposition The construction of the i-th lot skeleton (i = 2 to 4) is (i-1)
In parallel with the press-fitting and sinking of the skeletons below the lot skeleton, in the same procedure as the construction of the first lot skeleton 2a, on the ground, scaffold assembly, rebar assembly, formwork assembly, concrete pouring,
It is carried out by each process of curing, dismantling the formwork and scaffolding.

When the construction of the i-th lot skeleton is completed, all the skeletons below the ith lot skeleton are press-fitted and sunk by the hydraulic pressure as described above, and in parallel with this press-fitting and sunk, the (i
+1) Build the lot skeleton.

8. Removal of equipment, etc. When the caisson frame 2 is completely laid down as described above,
Dismantle the tower crane 14 and grab hopper 15,
The pressure girder 11 and the hydraulic jack 10 are removed. The earth anchor 9 is left as it is.

9. Bottom concrete pouring, completion Finally, the caisson digging work is completed by pouring concrete for connecting the first lot skeleton 1a and the foundation pile.

In order to safely and quickly perform a large-scale caisson laying work, as described above, in which a large number of personnel and equipment are operated at the same time, an operator uses a subsidence gauge to gain experience as in the past. It is impossible at all to implement it by the method of using intuition.

Therefore, in the present embodiment, a thorough safety management system formed by extracting the dangerous items expected for each work process in advance and taking countermeasures against them, and a scientific system without relying on experience or intuition An informationized semi-automatic press-fit management system based on various theories and data actually collected is applied.

The safety management system and the computerized semi-automatic press-fitting management system described above are not directly related to the blade skeleton body according to the present invention, and a detailed description thereof will be omitted. However, the angle management of the slope of the soil, which is related to the blade skeleton body 1 according to the present invention among only one safety management item, will be described below.

In this caisson construction, the soil quality changes to loam, clay and sand as the ground is dug.
This means that the natural slope angle of the excavated soil changes, and when excavating with a uniform excavation method, an imbalance between the soil resistance and the caisson load occurs, causing rapid caisson settlement. It also causes a lack of subsidence.

Therefore, in this embodiment, control is performed so that the slope angle is changed according to the soil quality as described below. This slope angle is managed by surely confirming the slope end position.

When the soil is loam layer, excavation is performed as shown in FIG.
~ The procedure is as shown in Fig. 14. That is, first, as shown in FIG. 11, from the trailing edge position P to the first lot body 2a.
The slope angle of the loam layer 19 under the beam 2g is set to about 45 degrees.

Next, as shown in FIG. 12, the soil 19a consisting of the loam layer 19 directly below the beam 2g is cut off at a right angle, leaving a portion 19b for supporting the caisson frame.

Then, as shown in FIG. 13, the caisson skeleton is press-fitted to push out the remaining soil 19b shown in FIG. 12 to the outside, and as shown in FIG. Excavate the soil that has run off and carry it out.

Further, in the case of the clay layer 20, first, as shown in FIG.
As shown in, the clay layer 20 is in contact with the blade skeleton body 1 and a part of the beam 2g, and the slope angle at the slope position P is about 45 degrees. Then, as shown in FIG. 16, after excavating the soil 20a by a predetermined thickness along the slope, as shown in FIG. 17, the caisson skeleton body 2 is press-fitted to remove the soil 20b corresponding to the soil 20a. Push it down. As a result, FIG.
As shown in, soil 20 that has run down the slope and the surface below it.
Excavate c and carry it out.

In the case of the sandy soil 21, first, as shown in FIG. 19, the sandy soil 21 contacts only the blade skeleton body 1 and the slope angle from the slope position P is about 60 degrees. To do.

Then, as shown in FIG. 20, the soil 21a having a predetermined thickness is excavated along the slope, and then, as shown in FIG. 21, the caisson frame 2 is press-fitted. As a result, FIG.
As shown in Fig. 2, the soil that has run down to the slope and the surface below it 2
Excavate 1b and carry it out.

As described above, by changing the work procedure for excavation and press-fitting according to the change in soil quality depending on the depth,
The safety of caisson construction will increase and the speed of construction will be constant. Further, when the cutting edge resistance force is biased depending on the location, it is possible to prevent the differential settlement by changing the excavation procedure depending on the location.

The caisson press-fitting and substituting work is carried out according to the following criteria. (1) Before the start of press-fitting, all members leave and make a roll call to confirm that the root cutting base is unattended. Also, all the machinery is
Collect under the opening 12. (2) Check the horizontalness of the caisson body 2.

(3) An average preliminary load (for example, about 50 tons) is applied to each hydraulic jack 10. At this time, for example, the pressure is increased from 0 ton to 50 ton, then returned to 0 ton, and this is repeated three times. This removes the initial frictional force generated by the soil around the caisson.

(4) After confirming that the initial frictional force has disappeared by the amount of strain, pressurization is applied to, for example, about 75 tons. (5) When the settlement does not proceed, the pressure is increased by 25 tons up to a maximum of 200 tons. In this case, a sufficient rest time (5 minutes or more in the example) is provided after the pressure increase to grasp the tendency of subsidence.

(6) For example, if the planned subsidence amount is not reached even if the amount exceeds about 175 tons, the cause is investigated and the countermeasure is reconsidered. In addition, a load of a predetermined weight (200 tons in the embodiment) or more is not applied. (7) When the planned subsidence amount is reached, release the hydraulic pressure of all the hydraulic jacks 10 and confirm that the caisson frame 2 is horizontal. At this time, be careful not to enter the root cut bottom until it is confirmed that the hydraulic pressure is completely released and the subsidence of the caisson body 2 is completely stopped.

The second embodiment of the blade skeleton body 1 will be described below. That is, the blade body 1 is cast in situ. To do so, first, as shown in FIG. 23, a hole 8b larger than the blade skeleton body 1 is excavated at a position corresponding to the blade skeleton body of the natural ground 8. This hole 8b is vertical on the outside (site border side),
The inside is inclined. When the ground where the caisson frame is to be settled has a soil that is likely to collapse, a lateral sheet pile 23 for retaining the mountain is provided along the boundary line of the site.

A concrete head plate 22 is installed on the bottom of the hole 8b. Next, a separator panel 24, which is an outer mold material of the blade skeleton body 1, and a control panel 25, which is an inner mold material, are separated from each other by the separator 2
Connect at 6 to create a mold for the blade skeleton 1.

The formwork thus created is used for the headboard 22.
Stand on top. At this time, an appropriate number of support rods 27 are inserted between the control panel 25 and the inclined surface of the hole 8b, and the control panel 24
Should be perpendicular to the headboard 22.

Next, the cutting edge metal fitting 28 is installed at the tip of the mold frame formed by the control panel 24 and the control panel 25.
As shown in FIG. 25, the blade hardware 28 includes an iron plate 28 a that contacts the control panel 24 and an iron plate 28 b that contacts the control panel 25.
And an iron plate 28 for connecting between the iron plate 28a and the iron plate 28b
c, an iron plate 29, an iron plate 30, and a friction cut 31.

The iron plate 28a and the iron plate 28b also serve as a mold. Further, the lower ends of the iron plate 29 and the iron plate 30 are fixed to the iron plate 28b and the iron plate 28a, respectively, and the upper ends thereof reach the upper first lot body 2a, respectively, as shown in FIG.

Further, yokes 32 are attached at right angles to the left and right edges of the iron plate 28a and the iron plate 28b, respectively. Yoke 3
2 is provided with a plurality of bolt holes 32a.

The cutting tool 28 having the above-mentioned structure is attached to the control panel 24.
And the control panel 25 are arranged side by side in the left-right direction, and the yokes 32 of the adjacent blade metal fittings 28 are connected by inserting bolts into the bolt holes 32a.

Further, the magazine 33 is attached to a position above the cutting edge metal fitting 28 of the control panel 24. Magazine 33
It has a built-in cylinder wrapped with a vinyl sheet or other slipping material, and when the blade body 1 sinks, this slipping material is pushed out to reduce the friction between the caisson surface and the soil. Have.

When the installation and connection of the above-mentioned blade hardware 28 and the installation of the magazine 33 are completed, concrete is poured between the control panel 24 and the control panel 25 to construct the blade skeleton body 1. The concrete pouring of the blade skeleton body 1 is performed together with the concrete pouring of the first lot skeleton 2a, and the blade skeleton body 1 and the first lot skeleton 2a are integrated. The blade skeleton body constructed in this manner has the blade tip metal piece 28 reinforced by the iron plate as described above, and therefore has extremely high pressure resistance.

[0074]

As described above, the caisson skeleton body according to the present invention is constructed in the ground independently of the caisson skeleton body constructed on the ground. It is possible to construct the blade skeleton body in parallel with the construction of the caisson skeleton by producing it in advance and excavating the hole in advance, and it is possible to remarkably reduce the construction period, which is an extremely excellent effect.

Further, since the caisson skeleton skeleton skeleton can be constructed on the ground, it is not necessary to use the supporting work or the like which is required in the conventional construction method. Therefore, the number of man-hours conventionally required to install and remove the support work is reduced to zero, and the construction work can be carried out in a short time.

Moreover, there is no fear of the differential settlement of the caisson skeleton when the supporting work is removed, and the safety, accuracy and efficiency of the construction can be improved.

Further, since the blade skeleton body is integrally formed by the iron plate and the precast concrete, and is constructed so that sufficient pressure resistance can be obtained even if it is unreinforced, it is lightweight and requires less material. Therefore, there is an effect that the work such as transportation and installation at the site becomes easy and the cost becomes low.

Further, since a friction cutting member is attached to the tip of the blade body, friction at the time of press-fitting and sinking of the caisson body can be reduced, and press-fitting and sinking can be performed smoothly, which leads to shortening of the construction period and improvement of accuracy. There is an effect called.

[Brief description of drawings]

FIG. 1 is a top view showing an example of caisson construction using a blade skeleton body according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a main part of the same AA.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a sectional view taken along line CC of FIG.

FIG. 6 is a right side view of the same.

FIG. 7 is a geological column diagram of the site of the same example.

FIG. 8 is an explanatory view showing an example of a blade skeleton body according to the present invention.

FIG. 9 is an explanatory diagram showing a state in which the blade skeleton body is installed in the ground.

FIG. 10 is an explanatory view showing the connection between the blade end skeleton and the first lot skeleton.

FIG. 11 is an explanatory diagram showing a state of soil around a blade opening skeleton before excavation when the soil is a loam layer.

FIG. 12 is an explanatory diagram showing a state of excavation around the blade skeleton body in the same case.

FIG. 13 is an explanatory view showing a state of the soil around the blade opening skeleton body at the time of press fitting in the same case.

FIG. 14 is an explanatory diagram showing a state of soil after press fitting in the same case.

FIG. 15 is an explanatory diagram showing a state of soil around a blade opening skeleton before excavation when the soil is a clay layer.

FIG. 16 is an explanatory view showing a state of excavation around the blade skeleton body in the same case.

FIG. 17 is an explanatory diagram showing a state of the soil around the blade opening skeleton body at the time of press fitting in the same case.

FIG. 18 is an explanatory diagram showing a state of soil after press-fitting in the same case.

FIG. 19 is an explanatory diagram showing a state of soil around a blade opening skeleton before excavation when the soil is sandy soil.

FIG. 20 is an explanatory diagram showing a state of excavation around the blade skeleton body in the same case.

FIG. 21 is an explanatory view showing a state of the soil around the blade opening skeleton body at the time of press fitting in the same case.

FIG. 22 is an explanatory diagram showing a state of soil after press-fitting in the same case.

FIG. 23 is an explanatory view showing a second embodiment of the blade skeleton body according to the present invention.

FIG. 24 is an explanatory diagram showing details of a lower portion of the embodiment.

FIG. 25 is an explanatory view showing a structure of a cutting edge metal article in the example.

FIG. 26 is an explanatory diagram showing a reinforcing bar in the example.

FIG. 27 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

 1 Blade skeleton skeleton 2 Caisson skeleton 3 Discarded concrete 4 Formwork 5 Supporting work 6 Cutting edge hardware 7 Beam 8 Ground 9 Ground anchor 10 Hydraulic jack 11 Pressed girder 12 Opening 13 Mini backhoe 14 Tower crane 15 Club hopper 16 Clamshell 17 Dump Tracks 18, 31 Friction cutting 19 Loam layer 20 Clay layer 21 Sandy soil 22 Headboard 23 Horizontal sheet pile 24, 25 Control panel 26 Spacer 27 Support rod 28 Cutting tool 29, 30 Iron plate 32 Yoke 33 Magazine

Claims (4)

[Claims] 1. A blade skeleton body provided in the lower end of the peripheral wall of the caisson skeleton and having a blade shape, which is constructed in advance in the ground where the caisson skeleton is sunk independently of the construction of the caisson skeleton. After that, it is connected to the caisson skeleton constructed on the ground, the method for forming a caisson blade skeleton skeleton. 2. The caisson's blade skeleton forming method according to claim 1, wherein the blade skeleton skeleton body uses a ready-made product which is preliminarily integrated with an iron plate and precast concrete. 3. The blade skeleton body is created by casting in-situ,
The caisson's blade skeleton forming method according to claim 1, wherein the blade metal is reinforced with an iron plate and is also used as a mold. 4. The caisson blade skeleton forming method according to claim 1, 2 or 3, wherein a friction cutting member is provided at a tip end portion of the blade skeleton body.