JP2004150070A - Treatment method for removed soil, and removed soil-treated construction method for foundation pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce considerably excavated mud as industrial waste, which is discharged from a job site, by utilizing the excavated mud, produced in the construction of a foundation pile, for soil improvement. <P>SOLUTION: A casing 10 for treatment, whose bottom is closed, is pushed in near a foundation pile constructing position, while ground is destroyed by a normal rotation through the use of a spiral blade 5 (a) and (b). The casing 10 is located at a prescribed depth without a lift of excavated soil (c). Improved soil 19, which is produced by mixing cement milk into the excavated mud discharged onto the ground in construction work for the foundation pile, is infilled into a steel pipe 1 of the casing 10 (d). The bottom of the the casing 10 is opened, and the casing 10 is pulled up while the improved soil 19 is discharged with a reverse rotation (e). Sediment, which is loosened by the spiral blade 5, is pushed downward; the surrounding ground is packed; and the casing 10 is pulled up onto the ground while the removal of the soil is suppressed. Thus, an improved soil column 20 is formed (f). The ground with a required strength is completed when the column 20 is solidified. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
When constructing a pile foundation, when excavating a pile hole, the soil and mud generated is treated to significantly reduce the amount to be treated as industrial waste. Related to the foundation pile method.
[0002]
[Prior art]
Generally, excavated soil is discharged from a foundation pile using a conventional concrete pile at the time of constructing the pile hole, and the excavated soil is treated as an industrial discharge, and is usually carried out outside a construction site. If the site surrounding the construction site is vacant and there is room on the site, a small amount of a solidifying agent may be added to fill the ground surface, but generally the excavated soil is not sufficiently treated and this is an environmental problem. Non-patent document 1). This has the same problem in the construction of the on-site development pile.
[0003]
In particular, in the method of injecting cement milk, etc., since the remaining soil to be treated is mixed with cement milk, it is necessary to remove it or neutralize it and discharge it to the outside of the site. It was complicated.
[0004]
On the other hand, in the so-called ground improvement method, in order to remove the soil on the surface layer of the ground by a mixing process, a ground improvement material is agitated and mixed with this, and the ground is buried in the ground, or as a method of embedding soil and mud in the ground, A sand compaction method and the like have been proposed.
[0005]
In addition, the mud generated by excavation is discharged from the excavation hole and mixed with a solidifying agent (cement etc.) outside the pile hole at the same time as an improved soil. The improved soil is pumped from the tip of the excavator auger and injected into the pile hole. A filling method has been proposed (Patent Document 1).
[0006]
In addition, the cylindrical casing and auger screw are excavated and penetrated into the ground, the mud generated by excavation is discharged out of the pile hole, and the mud is mixed and stirred with a cement-based solidifying agent on the ground and filled in the casing. (Patent Document 2).
[0007]
[Non-Patent Document 1] “From survey and design of pile foundation to construction”, 2nd revised edition, Japan Society of Geotechnical Engineers, May 5, 1993, pp. 538 to 539.
[Patent Document 1] JP-A-8-260450
[0009]
[Patent Document 2] JP-A-8-151627
[0010]
[Problems to be solved by the invention]
As for disposal of excavated soil, removal from the site as an industrial waste requires a new disposal site after treatment, which is environmentally and economically burdensome.
[0011]
In the case of the existing ground improvement method, in the case of the mixing process, the land at the construction site is generally small because the disposal amount is limited on the ground surface layer by the simple mixing process because it is generally narrow, so disposal in the construction site has been expected. . In addition, the sand compaction method has disadvantages such as the necessity of separate facilities, high vibration and noise, and the limited soil quality that can be employed.
[0012]
In addition, the above-described methods for disposal at the construction site have the following problems.
[0013]
That is, in the method of Patent Document 1, the excavation rod is structurally complicated because the excavation rod also serves to discharge the excavated soil and inject the improved soil, and the excavated soil is press-fitted through the hollow hole of the rod. Had to be finely ground. In Patent Document 2, it is difficult to discharge the entire excavated soil at the same time as the auger excavation and the penetration of the casing. Further, since the excavated soil is mixed with the solidifying agent and then filled into the casing, it cannot be embedded at the same time as the ground excavation. There is a disadvantage that a temporary storage space is required and time is required separately.
[0014]
In general, the improvement of the ground at the construction site and the formation of the foundation pile have been carried out separately and independently, and both have been carried out on the same ground, and an environmentally friendly construction method with less discharge and discharge has not been proposed.
[0015]
[Means for Solving the Problems]
However, according to the present invention, the processing casing is laid down on a site or the like where the foundation pile is constructed, and the improved soil formed by improving the excavated mud generated in the construction of the foundation pile is filled in the processing casing. Solved the point.
[0016]
That is, the present invention
(1) On the site where the foundation pile is to be constructed or on the site adjacent to it, the treatment casing whose tip is closed is pushed into the ground and laid.
(2) Improve the excavated mud discharged to the ground by constructing the foundation pile to form improved soil.
(3) The improved soil is filled in the processing casing.
(4) The processing casing is pulled up to the ground while opening the processing casing tip and releasing the solidifying means into the ground from the tip of the processing casing to form an improved earth pillar.
(5) An earth discharging method characterized by taking the above procedure.
[0017]
Further, in the above, the processing casing is an earth discharging method in which a spiral blade is attached to an outer periphery of a distal end portion of a steel pipe.
[0018]
Also, other inventions
(1) In a site where a foundation pile is to be constructed, a processing casing having a closed end is pushed into the ground at a “predetermined position where the foundation pile is constructed” and is laid.
(2) After or in parallel with the subsidence of the processing casing, the foundation pile is constructed by an optional method, and the excavated mud is discharged to the ground, and the excavated mud is subjected to an improvement treatment to improve the improved soil. To form
(3) The improved soil is filled in the processing casing.
(4) Opening the front end of the processing casing and lifting the processing casing to the ground while discharging the improved soil into the ground from the front end of the processing casing to form an improved soil column. .
(5) This is a foundation pile construction method for treating earth removal characterized by taking the above-described procedure.
[0019]
Further, in the above, the "predetermined position around the position where the foundation pile is constructed" is a comparatively soft ground, and the foundation pile construction method for processing the earth removal to be a plane position including the ground requiring ground improvement. is there. Furthermore, the processing casing is a foundation pile construction method for processing earth removal formed by attaching spiral blades to the outer periphery of the tip of a steel pipe.
[0020]
When the excavated mud in the above is adopted a ground having a high moisture content or a construction method in which water is injected at the time of excavation, excavation mud close to the muddy water is generated, and a ground or a dry construction method having a small moisture content is employed. Excavated soil close to the soil occurs, and these muddy water and soil are collectively referred to as excavated mud.
[0021]
In addition, the adjacent site in the above is a site different from the site on which the foundation pile is constructed, and by a general transport means, from the position of the foundation pile to the position of the casing for treatment, the excavated mud before treatment or after treatment. The site is far enough to carry the improved soil.
[0022]
In addition, the improvement treatment of the excavated mud in the above refers to a method of mixing a solidified material into the excavated mud and performing agitation treatment, and a method of dehydrating the excavated mud, and various methods such as sand, crushed stone, and clay. It also includes a treatment performed alone or in combination with each method such as a method of mixing and stirring the ground material. Here, the solidified material refers to a hydraulic material such as cement milk, and the solidifying means is a material obtained by mixing the solidified material with excavated mud and solidifies in the ground to increase the strength from the surrounding ground. A material that can be made.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
(1) First, before drilling a pile hole, a processing casing consisting of a steel pipe with a spiral plug with a closed bottom is penetrated and buried at a required point near the pile drilling point where the ground improvement is required, and the drilling mud is buried. A hollow portion is provided.
[0024]
Next, a pile hole is excavated by a predetermined method by a preliminary excavation method or a middle excavation method, and a soil cement layer having a predetermined solidification strength is filled in the pile hole. Excavated mud mixed with water or cement milk or the like injected during or after excavation of the pile hole is discharged to the ground.
[0025]
Next, in accordance with the discharge, an appropriate amount of a solidifying agent (appropriate type) is added to the discharged excavated mud to form a semi-kneaded improved soil having a predetermined solidification strength. The improved soil is poured into the hollow portion of the prepared treatment casing.
[0026]
Next, the bottom of the processing casing is opened and the processing casing is lifted to the ground while rotating, and the improved soil is discharged from the bottom. The improved soil is left underground to build the improved pillars. If the improved soil column solidifies, the ground with the required strength will be completed.
[0027]
In this method, an improved soil column is sequentially formed in the same manner as the excavation of each pile hole, and the ground improvement work is completed almost simultaneously with the construction of the pile hole.
[0028]
(2) In the above-mentioned pile hole excavation by pile excavation, the method of burying a ready-made pile after pre-drilling, the middle digging method of burying a ready-made pile at the same time as the excavation of a pile hole, and the discharge during the construction of a pile foundation such as an on-site pile. It can be used for general excavated mud, and can be used for general excavated mud.
[0029]
If the soil around the pile is strengthened by injecting a solidifying agent such as cement milk during the formation of the pile hole, and the separation of the two at the discharge is troublesome, the drilling mud improved to some extent Since it is a mixture, it is easy to adjust the ground to a predetermined solidification strength, which is particularly effective.
[0030]
(3) The casing for treatment is composed of a steel pipe with spiral blades and is embedded while rotating. The shape, thickness and size of the spiral blades are adjusted by the ground, and the balance between the pushing speed and the load on the driving machine is adjusted. By embedding the processing casing, the excavated mud is buried so as not to be discharged.
[0031]
In addition, the bottom of the steel pipe is closed at the time of embedding, and after the improved soil is poured into the treatment casing, the steel pipe is opened or partially opened by reverse rotation of the steel pipe, and the spiral blade pushes the ground around the steel pipe. While hardening, the improved soil inside the steel pipe can be left underground while pulling out the steel pipe.
[0032]
(4) Regarding the mixing and blending of excavated mud and solidifying agent, the ground should be improved in accordance with the required ground improvement specifications (ground strength, etc.) of the ground to be improved and buried in the hollow part of the steel pipe. If necessary, dewatering treatment can be performed to adjust the moisture content of the improved soil.
[0033]
Further, on the ground of the construction site, the ground can be appropriately formed on the improved ground by the following method in accordance with the discharge of the excavated mud.
-Improve the buried ground as it is, without adjustment, with the excavated mud being slightly crushed.
-An improved soil column made of soil cement that mixes excavated mud and cement milk (solidifying agent) to achieve a predetermined solidification strength.
・ If the excavated mud is sand, improved soil columns with sand piles.
・ If the excavated mud is crushed stone, the improved soil column using crushed stone piles.
[0034]
Embodiment 1
An embodiment of the present invention will be described with reference to FIGS.
[0035]
[1] Processing casing 10
[0036]
A short steel pipe (outside diameter D ₂ ) 3 is fitted and fixed to the lower end of the steel pipe (outside diameter D ₀ , length L) 1, and a spiral blade 5 is protruded from the outside surface of the short steel pipe 3. The spiral blade 5 is formed by twisting a donut-shaped base (outer diameter D ₃ ) cut at one radius 6.
[0037]
Further, a bottom cover 7 is attached to the lower end of the steel pipe 1, and can be opened by an operation from the ground (not shown). As described above, the processing casing 10 is formed. The lid 7 is fitted inside the short steel pipe 3 in a state of contacting the end face of the steel pipe 1.
[0038]
The length L of the steel pipe 1 is selected according to the thickness (depth) of the soft ground layer to be improved. Outer diameter D ₀ of the steel tube 1, the amount of discharge excavated soil to be treated, length L, a by embedding intervals like the processing casing 10 is appropriately selected.
[0039]
[2] Construction of foundation pile 21
(1) At the construction site of the building, the area corresponding to the ground having relatively weak ground strength (so-called soft ground) is defined as the ground improvement area 13 (FIG. 2 (c)). The processing casings 10 and 10 are buried.
[0041]
In the embedding of the processing casing 10 in the above, the processing casing 10 is attached to the tip of the auger 15 of the pile driver (FIG. 2A), and when rotated forward, the processing is performed on the ground while breaking the ground with the spiral blades 5. The casing 10 can be pushed in and penetrated (FIG. 2B).
[0042]
Here, since the lid 7 is always pressed from below in the state of being pushed downward, the lateral movement of the steel pipe 1 is restricted by the short steel pipe 3 while being attached to the bottom of the processing casing 10. The bottom of the steel pipe 1 can be closed while being in contact with the lower surface. Therefore, the excavated soil crushed by the spiral blades 5 stays directly above the spiral blades 5 and is not lifted because the bottom of the processing casing 10 is closed by the lid 7 and there is no upward discharging means. Therefore, the collapsed excavated soil remains around the steel pipe 1 of the processing casing 10, and the earth is not discharged to the ground.
[0043]
When the processing casing 10 reaches a predetermined position, the auger 15 is removed (FIG. 2C). In a similar process, a required number of processing casings 10, 10 are buried. In addition, the embedding position of the processing casing 10 in the above-mentioned case needs to be embedded at a position away from the foundation pile 21 to such an extent that the performance of the foundation pile 21 to be constructed is not hindered.
[0044]
(2) Next, a pile hole is excavated by a pre-drilling method or a middle excavation method, and a soil cement layer having a predetermined solidification strength is formed in the pile hole. Subsequently, the ready-made pile is lowered and buried in the pile hole (not shown).
[0045]
(3) The excavated soil 17 discharged to the ground 22 during the excavation of the pile hole, or the excavated soil 17 mixed with water or cement milk injected after the excavation is discharged to the ground and stored in the processing space 18 (FIG. 3 ( a)). Next, according to discharge, a solidifying agent is appropriately added to the excavated soil 17 to form a semi-kneaded improved soil 19 having a predetermined solidification strength.
[0046]
(4) Next, the improved soil 19 is filled into the steel pipe 1 of the processing casing 10 (FIGS. 2D and 3A). In addition, the filling can be performed by any method such as a method of filling from the vicinity of the bottom 11 of the processing casing 10 using a tremy tube or a method of dropping from the vicinity of the ground 22, and a special equipment for injection. Does not require
[0047]
(5) Next, the auger 15 is attached to the upper end of the processing casing 10. When the processing casing 10 is rotated in the reverse direction by the auger 15 and the processing casing 10 is raised, the bottom lid 7 is detached from the bottom 11 of the processing casing 10 (see a chain line 7 in FIG. 1C), and the processing casing 10 The improved soil 19 is pulled out from the bottom 11 together with the bottom lid 7 while discharging (FIG. 2 (e)). By this reverse rotation, the earth and sand loosened during excavation by the spiral blades 5 of the processing casing 10 can be pressed downward, the surrounding ground can be compacted, and soil discharge can be suppressed.
[0048]
(6) When the processing casing 10 is pulled up to the ground, the improved soil column 20 is formed (FIG. 2 (f)), and if the improved soil column 20 is solidified, the ground having the required strength is completed.
[0049]
(7) In this method, the improved soil columns 20, 20 are sequentially formed in the same manner simultaneously with the excavation of each pile hole, and the ground improvement work is completed substantially simultaneously with the construction of the pile hole (FIGS. 3A and 3B). In the above, when a lot of excavated soil 17 is discharged to construct one foundation pile 21, the method of (3) to (6) is repeated, and one or a plurality of The improved soil columns 20, 20 of the book are formed. When the excavated soil is less discharged, one improved soil column 20 is formed corresponding to the plurality of foundation piles 21.
[0050]
[3] Another embodiment
(1) In the above embodiment, the bottom cover 7 was inserted into the inside of the short steel pipe 3 and was brought into contact with the lower surface of the steel pipe 1, but the short blade 3 was not provided, and the spiral blade 5 was directly attached to the steel pipe 1. When attached, the bottom cover 7 is inserted into the steel pipe 1 and a stopper for restricting the rise of the steel pipe 1 is attached (not shown).
[0052]
Further, in the above embodiment, when the processing casing 10 is pushed in, the bottom lid 7 seals the bottom of the steel pipe 1 to keep the hollow inside the steel pipe 1 against the earth pressure when the processing casing 10 is pushed in. When the steel pipe 1 is lifted, a part or all of the bottom is opened, and the structure is optional as long as the filled improved soil can be discharged from the bottom.
[0053]
For example, a curved portion of a fan-shaped bottom cover piece 7a divided into four in the radial direction may be attached to the bottom of the processing casing by a hinge 8 (FIG. 4). In this case, when the processing casing 10 is pushed in, the bottom of the steel pipe 1 can be sealed against the earth pressure, and when the processing casing 10 is pulled up, the bottom cover pieces 7a, 7a rotate by the hinges 8. Then, the bottom can be opened (FIGS. 4 (a) and 4 (b); chain line illustration 7a).
[0054]
Further, as another bottom cover, a fan-shaped bottom cover piece 7a divided into four in the radial direction is rotatably mounted in a horizontal plane, and when the processing casing 10 is pushed in (the processing casing 10 is normally rotated). When the bottom cover piece 7a closes the opening provided on the bottom 11 and the processing casing 10 is pulled up (reverse rotation of the processing casing 10), the bottom cover piece 7a rotates to open the opening provided on the bottom 11. (Not shown).
[0055]
Further, as another bottom cover, an inner cylinder whose bottom is closed can be inserted into a steel pipe 1 having a spiral blade 5 attached and an open bottom, so that the bottom of the inner cylinder can be used as a bottom cover (illustration shown). Not). In this case, when the processing casing 10 is pushed in, the steel pipe 1 is pushed in with the inner tube, and after the inner tube is pulled out to a predetermined depth, the steel tube 1 is filled with the improved soil.
[0056]
(2) In the above embodiment, the treatment casing is configured by attaching the spiral blades 5 to the steel pipe 1. However, if the treatment casing has a hollow portion into which the improved soil can be injected and can be buried in the ground with the bottom closed. The structure is optional (not shown).
[0057]
(3) In the above embodiment, the processing casings are arranged in parallel at substantially equal intervals (FIG. 3A), but the required number is buried due to the distribution of ground strength in the plane direction and the presence of obstacles underground. Arrangement is optional (not shown) as long as it is possible and the required ground strength can be improved.
[0058]
(4) In the above embodiment, the processing casing 10 is buried prior to the construction of the foundation pile 21, but it is not necessary to embed all the processing casings 10 first. That is, it is sufficient that at least as many processing casings 10 as the number of the processing casings 10 to be filled with the improved soil are mixed before the improved soil is completed by mixing the solidified material with the excavated mud generated in the construction of the foundation pile.
[0059]
(5) In addition, the construction method of the foundation pile 21 in the above-mentioned construction can correspond to an arbitrary construction method such as an on-site construction pile for putting a reinforced cage and concrete in an excavated pile hole. Further, each method can cope with the discharge of arbitrary components discharged on the ground (for example, excavated mud mixed with various excavation aids and the like).
[0060]
(6) In the above, if the improved casing column 20 is formed by burying the processing casing 10 in the site where the foundation pile 21 is constructed, the treatment can be efficiently performed. When there is a ground to be improved in a nearby place, for example, the improved casing 20 may be formed by burying the processing casing 10 in an adjacent site, an opposite site, or the like (not shown). In this case, a processing space 18 is installed on the site where the foundation pile 21 is constructed or on a nearby site, and a means for transporting the excavated soil 19 from the position of the foundation pile 21 to the processing space 18 or a processing casing from the processing space 18 A means for transporting the improved soil 19 to 10 is required separately. Therefore, the present invention can be applied to the case where there is a transport means, even if the position of the foundation pile 21 and the position of the processing casing 10 are separated to some extent.
[0061]
【The invention's effect】
(1) Since the excavated mud is used on the same construction site while being mixed with the solidifying agent injected during the construction of the pile hole, the effect of greatly reducing the discharge of excavated mud outside the site is improved. is there. There is also an effect that it is not necessary to carry it out of the site and to dispose of the industrial waste thereafter. In particular, even if excavated mud containing various solidified materials injected into the pile hole is discharged, the solidified material can be added and used as it is as an improved soil without treating the solidified material contained. is there.
[0062]
(2) By using excavated mud discharged to the ground as the improved soil, it can be used as ground improvement within the site. The ground improvement can be performed at the predetermined position in the same site by using the discharged soil at the same time as the construction of the pile hole, so that it is not necessary to perform a new ground improvement work. That is, there is an effect that the procurement and construction of new ground improvement equipment and materials become unnecessary.
[0063]
(3) In addition, since the processing casing is used while being buried while rotating, the improved soil is buried in the inside thereof, and the improved soil is left on a predetermined ground at the same time as the processing casing is pulled out, so that embedding is easy. In addition, there is an effect that the excavated soil related to embedding of the improved soil is not required to be miniaturized or injection equipment is required. Further, if a steel pipe with a spiral is used as the processing casing, the ground can be compacted by pushing in the processing casing, since there is no earth removal in the embedding of the processing casing.
[0064]
(4) At the same time as excavation of pile holes, improvement and embedding of excavated mud is performed in parallel, so there is no need for a large dedicated pile area to store the entire amount of excavated mud, and a small amount that is discharged from one foundation pile This has the effect of requiring only a small storage space where the solidifying agent can be mixed with the excavated mud.
[0065]
(5) The pile hole excavation work and the embedding work of the processing casing can be performed by the same machine, so that there is no need to install a new machine, and there is an effect that the work can be easily performed only by devising the construction order of the machines. Further, since the processing casing can be repeatedly used, it is economical to manufacture the casing with increased strength.
[Brief description of the drawings]
FIG. 1 is a front view, FIG. 1 (b) is a plan view, and FIG. 1 (c) is a longitudinal sectional view of a processing casing used in an embodiment of the present invention.
FIGS. 2A to 2F are schematic longitudinal sectional views illustrating a processing method of the present invention.
FIG. 3A is a plan view of a foundation pile group (site) constructed according to the present invention, and FIG. 3B is a cross-sectional view taken along line AA in FIG.
4A and 4B show another processing casing used in the embodiment of the present invention, in which FIG. 4A is a partial longitudinal sectional view, and FIG. 4B is a bottom view.
[Explanation of symbols]
Reference Signs List 1 steel pipe 5 spiral blade 6 one radius 7 bottom lid 10 processing casing 11 processing casing bottom 13 ground improvement area 15 auger 17 excavated soil (excavated mud)
18 Processing space 19 Improved soil 20 Improved soil column 21 Foundation pile 22 Above ground

Claims (5)

(1) On the site where the foundation pile is to be constructed or on the site adjacent to it, the treatment casing whose tip is closed is pushed into the ground and laid.
(2) Improve the excavated mud discharged to the ground by constructing the foundation pile to form improved soil.
(3) The improved soil is filled in the processing casing.
(4) The processing casing is pulled up to the ground while opening the processing casing tip and releasing the solidifying means into the ground from the tip of the processing casing to form an improved earth pillar.
(5) An earth removal method characterized by taking the above procedure. The earth removal treatment method according to claim 1, wherein the treatment casing is configured by attaching a spiral blade to an outer periphery of a tip portion of the steel pipe. (1) In a site where a foundation pile is to be constructed, a processing casing having a closed end is pushed into the ground at a “predetermined position where the foundation pile is constructed” and is laid.
(2) After or in parallel with the subsidence of the processing casing, the foundation pile is constructed by an optional method, and the excavated mud is discharged to the ground, and the excavated mud is subjected to an improvement treatment to improve the improved soil. To form
(3) The improved soil is filled in the processing casing.
(4) Opening the front end of the processing casing and lifting the processing casing to the ground while discharging the improved soil into the ground from the front end of the processing casing to form an improved soil column. .
(5) A foundation pile method for treating earth removal, which is characterized by taking the above-described procedure. The method according to claim 3, wherein the "predetermined position around the position where the foundation pile is constructed" is a relatively soft ground and a plane position including the ground requiring ground improvement. The foundation pile construction method for treating earth removal according to claim 6, wherein the treatment casing is configured by attaching a spiral blade to an outer periphery of a tip portion of a steel pipe.

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