JP3367042B2 - Pile construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] [0001] The present invention relates to an impermeable layer ground.
The upper and lower permeable ground exist above and below
Piling in ground containing contaminated groundwater
It relates to the pile construction method in the case. [0002] 2. Description of the Related Art An opaque material comprising a clay layer and a silt layer in an intermediate layer.
Permeable layer that includes the water layer ground and the sand layer and gravel layer above and below it
In the aquifer ground having
Often have groundwater inside.
No. Such groundwater is used as industrial water and domestic water.
Has important applications. However, due to recent industrial activities, etc.
Harmful pollutants may enter the groundwater
Condition occurs frequently. Under these circumstances, impervious
The permeable layer ground exists above and below the layer ground,
When the aquifer contains contaminated groundwater,
Driving piles that penetrate the aquifer ground and reach the lower aquifer ground
In the case of construction or after construction,
Contaminated groundwater contained in the upper permeable ground
The water will flow into the aquifer ground and will
The existing clean groundwater will be polluted
Had become. [0003] However, conventionally,
Underground included in the lower permeable ground
Driving piles that can effectively prevent water contamination
Because there was no method,
Sewage pollution will progress, and effective use of groundwater
Not only can not do this, but also have a negative impact on the natural environment.
Was to be dropped. In particular, cadmium in contaminated groundwater
When toxic substances such as compounds and cyanide are mixed
Had become a serious problem. The present invention overcomes the above disadvantages.
This was done to remove the impervious ground.
The upper and lower permeable grounds exist above and below
In the ground containing contaminated groundwater, the impermeable layer ground
When placing a pile that penetrates and reaches the lower
During or after pile driving, the soil in the upper permeable
Prevents dyed groundwater from flowing into the lower permeable ground
To provide an effective pile construction method for
It is. [0004] SUMMARY OF THE INVENTION In short, the present invention provides
The permeable ground exists above and below the permeable ground,
Where the permeable ground has contaminated groundwater containing pollutants
A pile construction method for placing a pile in
Replacement material for preventing the contaminant from entering the center
The upper permeable ground inside the pile construction area using
(B) The pile construction area
Pile driving to penetrate piles to a specified depth through
Providing a pile construction method characterized by the following steps:
Is what you do. That is, the present invention relates to a pile construction method using a replacement material.
By replacing the upper permeable ground inside the area,
By preventing contaminants from entering the center of the construction area
Contaminated groundwater flowing down the gaps around the pile surface
Of contaminated pollutants into the lower permeable ground
And clean groundwater contamination in the lower permeable ground
It is to prevent. [0006] BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a pile construction method according to the present invention
An example of the mode will be described in detail with reference to the accompanying drawings. still,
The target ground for applying this method is shown in Figs.
Impermeable layer consisting of clay layer and silt layer in the middle layer
Permeable water including sand layers and gravel layers above and below
A ground having a layered ground 1, 1 ', 3, 3'
Also in the embodiment shown, the construction method on such ground
However, the permeable ground and the impermeable ground intersect.
Apply the same method to the mutually existing ground, etc.
It is possible to cope with this. [0007] First embodiment First, the first embodiment, which is the most basic embodiment, will be described.
Will be described. The pile construction method according to the present invention is shown in FIG.
As described above, the first step, the upper permeable ground replacement step, and the second step
It is constituted by each step of the pile driving step which is the step.
First, the first step, the upper permeable ground replacement step
explain. In this process, the pile construction area is
To prevent contaminants from entering the central area 4a
Material, i.e., for example, a material that blocks the above contaminants,
In other words, it is reactive and adsorbent
A material for preventing the above contaminants from entering the work area center 4a
Any one of the materials, or any of the above
With the replacement material combining the materials, the inside of the pile construction area 4 is
In this step, the upper permeable ground 1 is replaced. [0008] Specifically, as shown in FIG.
The pile construction area penetrates the upper permeable ground 1 containing dyed groundwater.
Excavation of the upper permeable ground 1 corresponding to the area 4
Performed by filling the board with the above replacement material
It is. This step is performed in the same way as the conventional method.
Done by For example, using various excavators,
Excavates the inside of construction area 4 and puts replacement material inside
Then, it can be performed by compacting or the like. In addition, above
Replacement of the above shall be performed only for the upper permeable ground 1
You can, but to further improve the effect, impervious
At the same time, replace the area that reaches the predetermined depth of the layer ground 2
Is desirable. In particular, the shape of the pile construction area 4 is particularly
There are no restrictions, determined according to the ground conditions, such as cylindrical and columnar
can do. In the upper permeable ground 1,
About the replacement rate, etc.
There are no restrictions as well, and it should be decided according to the ground conditions
Can be. However, mortar and concrete described later
The upper permeable layer ground 1 is replaced with the impermeable material M.
In such a case, the ground of the pile construction area 4 is hardened,
Pile driving after replacement becomes difficult. Therefore, FIG.
As shown, the pile construction area 4 ′ of the upper permeable
The extracorporeal tube 10 is installed, and the pile driving after replacement is performed.
Space for pile driving 11 is secured, and pile driving is performed in this area.
(See the second embodiment for details). Various materials are used as the replacement material.
Are not limited to the following materials:
However, as a material for blocking contaminants, an impermeable material M
Are representative materials. Also reacts to pollutants
Infiltration of contaminants into pile construction area 4
The materials that prevent stabilization include stabilizing materials, decomposition materials, and adsorption
Materials are representative materials. Below,
The properties of the replacement material will be described. The impermeable material M is formed of the impermeable material M
Contaminated groundwater flowing into the pile construction area 4 after hardening
Is a substance that has the effect of blocking mortar,
A REIT or the like is used. That is, using the water-impermeable material M
The purpose is to place the target pile construction area 4 with the material.
In this way, the entire pile construction area 4 is made to be impermeable ground.
To block contaminated groundwater from the outside
The purpose is to prevent intrusion of contaminants into the portion 4a. [0012] The stabilizing material reacts directly with the contaminants.
It is a substance having the property of forming an insoluble substance. Toes
The purpose of using stabilizing materials is to dissolve in contaminated groundwater.
Of the above contaminants existing in the pile construction area 4
By converting the material to an insoluble substance depending on the material,
Separates the above pollutants from dyed underground water and outside the pile construction area
By removing at the part 4b, the outer part 4b
Contaminated groundwater flowing into the
To prevent intrusion of contaminants into the work area center 4a
is there. However, species of pollutants contained in contaminated groundwater
Different stabilizing materials react to the pollutant
Therefore, depending on the situation of the contaminated groundwater as explained below
It is necessary to determine a stabilizing material to replace. For example, when the pollutant is a hexavalent chromium compound,
Ferrous sulfate and sodium sulfite as stabilizing materials
And reducing agents such as metabisulfite. this is,
Hexavalent chromium compounds are readily soluble in water, but trivalent chromium
The compound utilizes the property of being hardly soluble,
To reduce the hexavalent chromium compound using the above reducing agent
More Cr (OH)_ThreeAnd Cr_Two(SO_Four)_ThreeInsoluble matter
Quality and remove it from contaminated groundwater. [0014] Same as when removing hexavalent chromium compounds above
Of other pollutants in contaminated groundwater
Safety measures for each contaminant are listed below.
The use of the stabilizing material helps to remove the pollutants.
It becomes possible. Pollutants are cadmium compounds,
In the case of thorium compounds and mercury compounds, stabilizing materials
Then, it is effective to use sodium sulfide. Ma
If the contaminant is a cyanide, the stabilizing material
It is effective to use sodium hypochlorite. Ma
If the contaminant is an arsenic compound, use it as a stabilizing material.
It is effective to use iron chloride. In addition, other
By using metal powder such as iron powder as a stabilizing material,
Of hexavalent chromium, cadmium, lead, selenium, arsenic, etc.
It is also possible to remove heavy metals. [0015] Decomposed materials should react with the above contaminants
Has the property of decomposing the contaminant and rendering it harmless
Substance. In other words, the purpose of using decomposed materials is
The above pollutants dissolved in the sewage are transferred to the pile construction area 4.
It is decomposed by the existing decomposition material, and the pile construction area outside 4
Detoxification of contaminated groundwater flowing into b
Prevents intrusion of contaminants into the center 4a of the pile construction area
To stop. However, contained in contaminated groundwater
Decomposition materials that react to the pollutant depending on the type of the pollutant
Due to different charges, replacement is required depending on the situation of contaminated groundwater.
It is necessary to determine the decomposition material for For example, pollutants
If organic chlorine compounds are contained as
The desired effect is obtained by adding iron powder as a raw material
be able to. [0016] Adsorbent materials have very large adsorption capacity
A porous material that can adsorb the above pollutants
Yes, activated carbon, coal ash, charcoal, lignite, zeolite, ben
Tonite or the like is used. That is, using an adsorptive material
The purpose is to remove the above pollutants dissolved in the contaminated groundwater,
Adsorption by the adsorptive material existing in the pile construction area 4
To remove directly and flow into the pile construction area outside 4b.
The incoming contaminated groundwater is finally rendered harmless,
The purpose is to prevent intrusion of contaminants into the core 4a. Next, the pile driving step will be described. Main construction
In the process, as shown in FIGS. 1B to 1C, the first step
Penetrated through the pile construction area 4 replaced by
In the process of driving the pile K to reach a predetermined depth in the board 3
Yes, it can be done in the same way as
And it is possible. In this process, regardless of the method of placing the pile K,
Basically, any method can be used. Obedience
Depending on the ground conditions, the impact method, embedded pile method,
It is possible to adopt various construction methods such as the cast-in-place pile method.
You. There is no particular limitation on the material and shape of the pile K.
No. Therefore, steel pile, ready-made concrete pile, prestress
Concrete piles, composite piles of steel and concrete, etc.
Of course can be constructed of other piles
Cast-in-place steel pipe concrete pile, expanded bottom as special foundation
Piles, wall piles, multi-column foundations, etc. can also be constructed. Change
In addition, by providing a projection or the like on the pile K, the adhesion of the pile K can be reduced.
It is also possible to increase. ◎ Second Embodiment As shown in FIG. 2, mortar, concrete, etc.
Of the upper permeable layer ground 1 '
In the construction method when replacing in the pile construction area 4 '
is there. In such a case, the ground of the pile construction area 4 'becomes hardened.
Therefore, it is difficult to drive the pile after replacement. That
In advance, the extracorporeal tube 10 is installed in the pile construction area 4 'in advance,
Secure space 11 for pile driving for pile driving after replacement
However, it is necessary to drive the pile into the relevant part. More specifically, first, FIG.
As shown, the upper permeable stratum inside the pile construction area 4 '
The board 1 'is made of a water-impermeable material M such as mortar or concrete.
Area for pile driving in the pile construction area 4 '
An extracorporeal tube 10 is installed near the area to the depth of the replacement area.
And the outer portion of the extracorporeal tube 10 in the pile construction area 4 '
Will be replaced only in the replacement region 4'c formed in
You. In this case, the inside of the extracorporeal tube 10 is replaced.
Instead, a space 11 for placing a pile is secured inside. still,
The method of installing the extracorporeal tube 10 is the same as the method conventionally used.
It can be done by a method. For example, by blow, vibration
Using the method, the extracorporeal tube 10 is penetrated into the ground of the pile construction area 4 '.
This is done by inserting Next, as shown in FIGS.
Then, the pile K 'is inserted into the pile driving space 11 in the upper permeable ground.
1 'and the impermeable layer ground 2'
It will be cast to reach a predetermined depth in 3 '.
After that, as shown in FIG.
Mortar or concrete
This step is completed by filling an impermeable material M such as
That's it. This means that the extracorporeal tube 10 and the pile K '
For the purpose of increasing the strength of the pile K '
You. In this embodiment, the driving of the pile K '
Regardless of the installation method, basically use any method
be able to. Therefore, depending on the ground conditions,
Adopt various methods such as embedded pile method and cast-in-place pile method
It becomes possible. Also, regarding the material and shape of the pile K ′,
There is no particular limitation. Therefore, steel piles, ready-made concrete
Pile, prestressed concrete pile, steel and concrete
That various types of piles such as composite piles can be constructed
Of course, as another special foundation,
It is possible to construct cleat piles, expanded piles, multi-column foundations, etc.
Wear. Further, in this case, projections are provided on the pile K 'and the extracorporeal tube 10.
Concrete, etc., pile K 'and extracorporeal tube 1
0 by improving the adhesion of
It is also possible to increase the strength of the pile K '. By the above method, mortar, concrete
Replace the ground in the replacement area 4'c using an impermeable material M such as
And the extracorporeal tube 10
Pollutant for pile driving due to the effect of blocking contaminated groundwater
It is possible to effectively prevent intrusion into the space 11.
It becomes possible. The heads of the stakes K and K 'have upper water permeability.
Even if it is buried in the ground of the layered ground 1, 1 '(see FIG.
), Even if it protrudes above it (in the case of Fig. 1),
No problem. [0024] According to the present invention, the above various substitution materials can be used.
By replacing the upper aquifer ground,
Prevention of contaminants contained in water from penetrating into the lower permeable ground
By stopping or detoxifying contaminants,
Prevent contamination of clean groundwater contained in aquifer ground
Can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) is a side sectional view showing a first embodiment of an upper permeable layer ground replacement process, and FIGS. 1 (b) and (c) are first executions of a pile driving process. It is a sectional side view which shows a form. FIG. 2 (a) is a side sectional view showing a second embodiment of the upper permeable layer ground replacement step, and FIGS. 2 (b), (c) and (d) show the second embodiment of the pile driving step. It is a side sectional view. [Description of Signs] 1 Upper permeable layer ground 2 Impermeable layer ground 3 Lower permeable layer ground 4 Pile construction area 4a Pile construction area central part 4b Pile construction area outer part 4'c Replacement area 10 External intubation 11 Pile driving space 12 gap K pile M impervious material

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toru Sueoka 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation (56) References JP 5-9925 (JP, A) JP Hei 7-224440 (JP, A) JP-A-57-112513 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/00 101 E02D 5/22 E02D 3/12 102 E02D 7/00

Claims (1)

(57) [Claims] [Claim 1] A permeable layer ground exists above and below an impermeable layer ground, and an upper permeable layer ground drives a pile into the ground having contaminated groundwater containing pollutants. (A) an upper permeable layer that replaces an upper permeable layer ground inside the pile construction area by using a replacement material for preventing intrusion of the contaminant into the center of the pile construction area. A pile construction method, comprising: a ground replacement step; and (b) a pile placing step of placing a pile to a predetermined depth through the pile construction area.