JP2000170175A - Execution method of footing beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable saving, a low cost and a short construction period by backfilling a ditch by improvement soil comprising a mixture of soil, consolidation material and water after a footing beam is arranged in a ditch excavated for footing beam setting to be set on a column. SOLUTION: A pile 1 is set on ground 2, and the upper part of the pile 1 is integrated with a footing 20 having a column 5. Footing beams 7, 9 are arranged in a previously excavated ditch and joined on the column 5. Improvement soil 11 comprising a mixture of excavated soil, consolidation material and water is charged in the ditch layer the footing beams 7, 9 to be backfilled. Thereafter, a water sealing plate 13 is set, after the mixture is consolidated, the surface is ground softly and sill concrete is executed. Thereby the compaction working of soil after backfilling and the supply of good quality soil are unneeded, the execution of the underground beam of saving, a short construction period, environment good and a low cost is made possible, and the disposal amount and cost of excavation residual soil can be reduced by the use of the evacuation production soil produced during the excavation of the ditch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground beam for an architectural structure having an underground beam and a civil structure.

[0002]

2. Description of the Related Art Underground beams are constructed by digging a groove in the ground, and after installing the beam, burying the soil in the space between the beam and the wall of the groove. At this time, in order to improve the workability of the type of work in the next process, the convenience of the ground in the future, or so that the backfill part does not sink or sink,
Compact the soil with relatively good quality soil. Also, the generated soil is
If the quality is not relatively good, dispose of it as surplus soil.

[0003] When the underground beam is made of steel, the underground beam is wrapped around with reinforced concrete or the steel beam itself is coated with a special coating to prevent corrosion in the ground. To Recently, Japanese Patent Application Laid-Open No. 4-315620
As disclosed in Japanese Unexamined Patent Publication, there has been proposed a proposal in which the entire foundation including the underground beam is covered with a seepage control sheet to block the surrounding foundation and thereby prevent corrosion.

[0004]

However, the conventional underground beam construction method has the following problems. First, when constructing an underground beam, it is necessary to compact the soil sufficiently, which takes time, construction time and cost. In addition, since it is necessary to use relatively high quality soil for backfilling, if the soil that constitutes the ground of the construction site of the building structure or civil engineering structure is not of relatively high quality, newly obtain backfill soil. In addition to this, there is a problem that it is necessary to dispose of the surplus soil in an amount larger than that obtained, which causes a large environmental load.

[0005] Further, in the method of winding reinforced concrete when the underground beam is made of steel, it is necessary to dig a groove more than necessary due to the space for assembling the mold, which increases the cost and the construction period, and requires a new method. There is also a problem that the amount of soil obtained and the amount of soil left after disposal increase. Further, in the case of the method of coating and coating the underground beam surface, the amount of excavated soil is reduced as compared with the case where reinforced concrete is wound, but there is a problem that the cost of the material of the underground beam itself is significantly increased. Furthermore, in the case of the method of covering the entire foundation including the underground beam with the impermeable sheet, the construction of the impermeable sheet becomes complicated in sections with complicated shapes such as joints between piles or columns and the underground beam. In addition, there is a problem that considerable labor and cost are required to improve the reliability of the water barrier at the contact point between the pile and the water barrier sheet. As described above, the conventional method has various problems that it takes time, cost, and construction time, and that it has a large environmental load.

The present invention has been made in order to solve such problems, and provides a method of constructing an underground beam capable of saving labor, reducing costs, shortening the construction period, and reducing the environmental load. It is intended to be.

[0007]

According to the present invention, there is provided a method of constructing an underground beam according to the present invention. The groove is backfilled with an improved soil made of a mixture with water.

The soil is characterized by using excavated soil generated during excavation of the trench.

Further, the solidified material is a cement-based solidified material or a lime-based solidified material.

[0010] Also, the underground beam should have at least 10
It is characterized by being covered with a thickness of cm.

[0011] Further, a waterproof plate is provided between the improved soil and the concrete between the soils to be cast on the improved soil.

[0012] The present invention is also characterized in that unevenness is formed on the upper surface of the improved soil to improve the water stoppage between the improved soil and the concrete between the soils cast on the improved soil. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 is a perspective view for explaining an embodiment of the present invention, FIG. 2 is a front sectional view, FIG. 3 is a sectional view taken along the line AA in FIG. 2, and FIG.
5 is a sectional view taken along the line BB in FIG.
It is -C sectional drawing. First, a completed state constructed according to the present embodiment will be described with reference to FIGS. 1 to 5, and then a construction procedure will be described. 1 to 5, reference numeral 1 denotes a plurality of piles installed on the ground 2, 20 denotes a footing for transmitting the stress from the column 5 to the pile 1, 5 denotes a column having a lower end inserted and installed in an upper end of the footing 20, 7. , 9 are H-shaped underground beams made of steel joined to the column 5 at right angles to each other.

Reference numeral 11 denotes an improved soil having a thickness of at least 10 cm and installed around the underground beams 7 and 9. The improved soil 11 is composed of a mixture of excavated soil, a solidified material and water, and the solidified material is a mixture of 1 m ³ of soil and 50 kg or more. As the solidifying material, a cement-based solidifying material (including cement) or a lime-based solidifying material is used. Reference numeral 13 denotes a water stop plate provided at a boundary between the improved soil 11 and the later-described soil concrete, which prevents groundwater from entering the underground beams 7 and 9 from the boundary. Reference numeral 15 denotes the concrete between the soils installed on the improved soil 11 and the ground 2, and 16 denotes the underground beam 7,
9 is a beam setting jig used when setting 9.

Next, the construction procedure will be described. Pile 1 on ground 2
Is installed, and the pile upper part is integrated with the footing 20 having the pillar 5. Next, the underground beams 7 and 9 are arranged on the pillar 5 in a previously excavated groove (excavated so that a gap of at least 10 cm is formed around the underground beams 7 and 9) and joined to the pillar 5. I do. Then, the improved soil 11 made of a mixture of the excavated soil, the solidified material, and the water is put into the groove in which the underground beams 7, 9 are laid, and backfilled. Then, the water blocking plate 13 is installed, and after the mixture is solidified, the surface thereof is lightly shaved and the concrete between the earth 15 is constructed.

Next, the effects of the present embodiment will be described from the viewpoint of the strength and corrosiveness of the improved soil. First, the intensity of the modified soil, the surrounding steel in the soil and the solidifying material (or 50kg to Sat 1 m ³⁾ and a mixture of water improved soil 10c
m, and after measuring the unconfined compressive strength of the improved soil after the improved soil was solidified, 2-3 kg over the initial to long term
f / cm ² . Therefore, it can be seen that the use of the improved soil eliminates the need to compact the ground.

Next, the corrosiveness will be described. FIG. 6 is a chart showing the relationship between the pH value of the ground and the corrosion rate of steel material,
The vertical axis indicates the corrosion rate, and the horizontal axis indicates the pH value. As can be seen from this chart, the corrosion rate sharply decreases when the pH value is about 11 or more. As a result of a separate investigation, it was found that if the peripheral surface of the steel material had a pH of 11 or more, a passive film was formed on the surface of the steel material, so that corrosion of the steel material hardly occurred. Therefore, when a steel underground beam is used, the pH value around the underground beam is set to 1
It can be seen that by setting it to 1 or more, the corrosion rate can be reduced to prevent corrosion.

FIG. 7 is a graph showing a follow-up survey of the pH of the improved soil.
This is a case where a portion deeper than 40 cm in depth is regarded as unimproved soil. As can be seen from this chart, the pH value of the improved soil having a depth of about 10 cm or more is 11 to 12. Therefore, it can be seen that the pH value can be adjusted to 11 to 12 on the peripheral surface of the underground beam by covering the steel underground beam with the improved soil at a thickness of 10 cm or more. At a position 10 cm or more away from the boundary of the improved soil, the pH value is 6 to 7, indicating that the pH does not affect the surrounding ground.

FIG. 8 is a graph showing the change over time of the pH value of the water passing through the improved soil. The vertical axis shows the pH value, and the horizontal axis shows the elapsed days. As can be seen from this graph, the pH value is maintained between 11 and 12 for a long period of time.

As can be seen from the above description of FIGS. 6 to 8, the periphery of the underground beams 7 and 9 is
improved soil using cement-based solidifying material with a thickness of at least 10 m
, The underground beams 7, 9 for a long time
The pH value of the peripheral surface can be maintained at 11 to 12,
As a result, a passivation film is formed on the peripheral surfaces of the underground beams 7 and 9 and corrosion of the underground beams 7 and 9 can be prevented.

As described above, according to the present embodiment, the use of the improved soil eliminates the need for compaction work, and causes special corrosion even when a steel underground beam is used. Corrosion can be prevented without taking measures.

In the first embodiment, the water blocking plate 1 is used to increase the water blocking between the ground 2 and the improved soil 11.
Although the example in which 3 is installed has been shown, the water blocking property may be enhanced by forming a water blocking wall by forming irregularities on the upper surface of the improved soil 11.

In the first embodiment, an example using a cement-based solidification material or a lime-based solidification material has been described. As the solidification material, the improved soil has a certain strength and a certain pH. It is not limited to these cement-based or lime-based solidified materials as long as they maintain the values (11 to 12). In addition, as long as the improved soil has a certain strength, pH
Even if the value is not constant, it goes without saying that it can be used for underground beams that do not need to consider corrosiveness.

Embodiment 2 FIG. 9 is a perspective view for explaining another embodiment of the present invention, FIG. 10 is a front sectional view, FIG. 11 is a sectional view taken along the line AA in FIG. 10, and FIG.
10 is a sectional view taken along line BB in FIG. 10, and FIG. 13 is a sectional view taken along line CC in FIG. Hereinafter, the second embodiment will be described with reference to FIGS. 9 to 13, the same parts as those in FIGS. 1 to 5 showing the first embodiment are denoted by the same reference numerals.

In the second embodiment, a deck plate is used as a floor slab, and slab concrete is cast on the deck plate. Since the basic configuration is the same as that of the first embodiment, only differences from the first embodiment will be described below. 16 is a beam setting jig used for setting the underground beams 7, 9; 19 is an underground beam 7, 9 at a pitch of 20 cm to 30 cm.
An angle member 21 is attached to the underground beams 7 and 9 via an attachment member 17 installed at the bottom, and a deck plate 21 is set with its peripheral edge placed on the angle member 19.

Next, the construction procedure will be described. Pile 1 on ground 2
Is installed, and the pile upper part is integrated with the footing 20 having the pillar 5. Next, the beam setting jig 16 is inserted into the groove (the underground beams 7, 9 are excavated so that a gap of at least 10 cm is formed around the underground beams 7, 9) in the pillar 5 in which the underground beams 7, 9 are excavated in advance. And bonded to the pillar 5. Then, the improved soil 11 composed of the mixture of the excavated soil, the solidified material, and the water is transferred to the underground beams 7, 9
Into the groove where it was laid and backfilled. And the water stop plate 1
3 is set, and after the mixture has solidified, its surface is lightly shaved off. After that, the mounting material 19 is changed from 20 cm to 30 c.
It is installed on the underground beams 7 and 9 at a pitch of m, and the angle member 19 is joined to the mounting member 17.

Next, the periphery of the deck plate 21 is placed on the angle member 19. Thereafter, concrete is cast around the underground beams 7 and 9 surrounded by the angle members 19 and on the deck plate 21. When casting concrete around the underground beams 7, 9, the angle members 19 serve as formwork.

According to the second embodiment, since the deck plate is used as the floor slab, the work of leveling and compacting the ground is not required when placing the concrete between the soil.

Embodiment 3 FIG. 14 is a perspective view for explaining another embodiment of the present invention, FIG. 15 is a front sectional view,
16 is a sectional view taken along line AA in FIG. 15, FIG. 17 is a sectional view taken along line BB in FIG. 15, and FIG. 18 is a sectional view taken along line CC in FIG. 14 to 18, the same parts as those in the first embodiment are denoted by the same reference numerals.

In the present embodiment, the present invention is applied to a structure different from that of the first embodiment in the structure of the basic portion, and the configuration other than the basic portion is the same as that of the first embodiment. First, FIG.
A completed state constructed according to the present embodiment will be described with reference to FIG. 18, and then the construction procedure will be described.
14 to 18, reference numeral 31 denotes a concrete-filled pile in which grout 34 (or concrete) is injected around and is filled with concrete 33 inside, and 5 denotes a lower end at the upper end of the concrete-filled pile 31. It is a pillar inserted and installed.

Underground beams 7, 9, improved soil 11, water stoppage plate 13,
The configurations of the concrete between the soil 15 and the beam setting jig 16 are the same as those in the first embodiment.

Next, the construction procedure will be described. The concrete-filled pile 31 is installed on the ground 32, and the column 5 is erected on the concrete-filled pile 31. Next, the underground beam 7,
9 is placed in a previously excavated groove (excavated so that a gap of at least 10 cm is formed around the underground beams 7, 9) and joined to the column 5. Then, the improved soil 11 made of a mixture of the excavated soil, the solidified material, and the water is put into the groove in which the underground beams 7, 9 are laid, and backfilled. Then, the water blocking plate 13 is installed, and after the mixture is solidified, the surface thereof is lightly shaved and the concrete between the earth 15 is constructed.

Embodiment 4 FIG. 19 is a perspective view for explaining another embodiment of the present invention, FIG. 20 is a front sectional view,
21 is a sectional view taken along line AA in FIG. 20, FIG. 22 is a sectional view taken along line BB in FIG. 20, and FIG. 23 is a sectional view taken along line CC in FIG. In the present embodiment, the present invention is applied to a structure having a different basic structure from that of the second embodiment. The configuration other than the basic structure is the same as that of the second embodiment. The structure of the base is the same as that of the third embodiment.
Therefore, the same reference numerals are given to the same parts as in FIGS. 9 to 13 and FIGS. 14 to 18 showing the second and third embodiments in FIGS. 19 to 23, and the construction procedure will be described below.

The concrete-filled pile 31 is installed on the ground 32 and the column 5 is erected on the concrete-filled pile 31. Next, the beam setting jig 16 is inserted into the groove (the underground beams 7, 9 are excavated so that a gap of at least 10 cm is formed around the underground beams 7, 9) in the pillar 5 in which the underground beams 7, 9 are excavated in advance. And bonded to the pillar 5. Then, the improved soil 11 made of a mixture of the excavated soil, the solidified material, and the water is put into the groove in which the underground beams 7, 9 are laid, and backfilled. Then, the water stop plate 13 is provided, and after the mixture is solidified, the surface thereof is lightly scraped off. Thereafter, the mounting members 19 are installed on the underground beams 7, 9 at a pitch of 20 cm to 30 cm, and the angle members 19 are further mounted.
To the mounting member 17.

Next, the periphery of the deck plate 21 is placed on the angle member 19. Thereafter, concrete is cast around the underground beams 7 and 9 surrounded by the angle members 19 and on the deck plate 21. When casting concrete around the underground beams 7, 9, the angle members 19 serve as formwork.

In the above description, the steel underground beam has been described as an example. However, the present invention is not limited to the steel underground beam, but may be applied to a reinforced concrete beam. It goes without saying that you can do it.

[0037]

Since the present invention is constructed as described above, the following effects can be obtained.

After the underground beam was placed in the trench excavated for the installation of the underground beam and installed on the pillar, the trench was backfilled with the improved soil consisting of a mixture of soil, solidified material and water. The need for soil compaction work and the procurement of high quality soil after backfilling is no longer necessary, and labor saving, short construction period, good environment, and low-cost construction of underground beams are possible.

Further, since the excavated soil generated during the excavation of the trench is used, the disposal amount and the cost of the excavated soil can be reduced.

Further, by using a cement-based solidifying material or a lime-based solidifying material as the solidifying material, corrosion can be prevented even if a steel underground beam is used.

In addition, the underground beam should have at least 10
cm, so that corrosion can be reliably prevented.

Further, since a water stop plate is installed between the improved soil and the concrete between the soils to be cast on the improved soil, it is possible to prevent groundwater from infiltrating into the underground beam side and to corrode the underground beam. Etc. can be prevented.

In addition, since unevenness is formed on the upper surface of the improved soil to improve the water stoppage between the improved soil and the concrete between the soils to be cast on the improved soil, the underground is similarly provided as described above. By preventing groundwater from entering the beam side, corrosion of the underground beam and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an underground beam construction state according to an embodiment of the present invention.

FIG. 2 is a front sectional view of an underground beam in an embodiment of the present invention in a construction state.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along the line BB in FIG. 2;

FIG. 5 is a sectional view taken along the line CC in FIG. 2;

FIG. 6 is a table showing the relationship between the soil pH value and the corrosion rate of steel.

FIG. 7 is a graph showing a follow-up study of the pH of the improved soil.

FIG. 8 is a graph showing the change over time of the pH value of the passing water that has passed through the improved soil.

FIG. 9 is a perspective view of an underground beam according to another embodiment of the present invention in a construction state.

FIG. 10 is a front sectional view of an underground beam according to another embodiment of the present invention.

11 is a sectional view taken along the line AA in FIG.

FIG. 12 is a sectional view taken along the line BB in FIG.

13 is a sectional view taken along the line CC in FIG.

FIG. 14 is a perspective view showing an underground beam construction state according to another embodiment of the present invention.

FIG. 15 is a front sectional view of another embodiment of the present invention in an underground beam construction state.

16 is a sectional view taken along the line AA in FIG.

17 is a sectional view taken along the line BB in FIG.

18 is a sectional view taken along the line CC in FIG.

FIG. 19 is a perspective view showing an underground beam construction state according to another embodiment of the present invention.

FIG. 20 is a front sectional view of another embodiment of the present invention in an underground beam construction state.

21 is a sectional view taken along the line AA in FIG. 20.

22 is a sectional view taken along the line BB in FIG.

23 is a sectional view taken along the line CC in FIG. 20.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pile 5 Column 7 and 9 Underground beam 11 Improved soil 13 Water stop board 17 Mounting material 19 Angle material 20 Footing 21 Deck plate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuhiro Imai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Hideaki Hoshi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun F-term in Honko Tube Co., Ltd. (Reference) 2D046 BA00

Claims (6)

[Claims] The present invention relates to a method of arranging an underground beam in a trench excavated for installation of an underground beam and installing the underground beam on a pillar, and then backfilling the trench with an improved soil comprising a mixture of soil, a solidifying material, and water. Underground beam construction method that is characteristic. 2. The underground beam construction method according to claim 1, wherein excavated soil generated during excavation of the trench is used as the soil. 3. The solidifying material according to claim 1, wherein the solidifying material is a cement-based solidifying material or a lime-based solidifying material.
Construction method of underground beam described. 4. The method according to claim 3, wherein the underground beam is covered with the improved soil with a thickness of at least 10 cm. 5. The underground beam according to claim 1, wherein a water stop plate is provided between the improved soil and concrete between the soil to be cast on the improved soil. Construction method. 6. The water-blocking property between the improved soil and the interstitial concrete cast on the improved soil by forming irregularities on the upper surface of the improved soil. The method for constructing an underground beam according to any one of claims 1 to 5.