JP2007120229A - Soil improving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical and safe soil improving method having little influence on the surrounding environment by which the soil of a construction area of large-scale and large capacity can be improved efficiently and in a short period by a comparatively compact system, a solidification material of various properties can be added with a high kneading efficiency and without a loss irrespective of the purpose and the use, and contribution can be attained to obtain the improved soil with high quality and stability. <P>SOLUTION: In the soil improving method, construction area A from which the surface layer soil H is taken by excavation for the soil improvement is partitioned into construction yards B each having a predetermined unit area. The surface layer soil H of a predetermined excavation depth S in the construction yard B of the unit area is collected and is conveyed to a soil improving area C in the construction yard B having a soil improving device 4 installed therein to conduct the soil improvement. Part or whole of the improved soil G is substantially returned to the place where the surface layer soil H is used to be. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a soil improvement method for replacing dredged soil, etc., deposited on the bottom of rivers, etc., which is soft and has a high water content, with good quality soil, and is particularly economical and efficient in a short construction period. It relates to a new soil improvement method that can be completed.

As a conventional soil improvement method, an in-situ agitation method using a stabilizer was adopted. That is, a powdery solidified material such as cement is spread from a predetermined height on the surface soil to improve the soil using a stabilizer, and at the same time, the surface soil is stirred and kneaded with the solidified material by the stirring blade of the stabilizer. The soil was improved. Patent documents 1 to 3 can be cited as documents relating to such a conventional soil improvement method. However, since the solidified material is in a powder form, it is likely to be scattered and may adversely affect the surrounding environment. Further, it has been pointed out that the stirring with the stirring blade tends to cause uneven kneading with the solidified material, and stable soil improvement cannot be performed efficiently. In addition, in the soil improvement method using a stabilizer, there is a lot of loss due to the solidified material flying away from the surface soil with wind, etc., and in addition, the mixing efficiency with the solidified material is low, so the solidification used There was a problem that a large amount of material was required, the material cost was increased, the construction period was prolonged, and the construction cost was further increased. Further, since the kneading efficiency with the solidifying material is low, there is a problem that the solidifying material that can be used depending on the purpose and application is limited.

JP 2003-64618 A JP 2000-7926 A Japanese Patent Laid-Open No. 54-12152

  The present invention has been made in light of the existence of such background technology and the problems of the background technology, and it is a relatively compact system for improving the soil quality of a large-scale, large-capacity construction area efficiently and in a short period of time. It is economical and safe because it can be added between various types of solidified materials without loss and with high kneading efficiency, regardless of the purpose and application, and can contribute to the improvement of high quality and stable soil quality. The objective is to provide a soil improvement method that has little impact on the surrounding environment.

  In order to solve the above-mentioned problem, the soil improvement method according to the first aspect of the present invention is a construction yard unit in which a construction area for cutting surface soil is divided into construction yards of a predetermined unit area for soil improvement. The soil is improved by collecting the surface soil having a predetermined cutting depth and transferring it to the soil improvement area in the construction yard where the soil improvement device is installed.

  According to the 1st aspect of this invention, since the transfer distance of the improved soil which improved the surface layer soil and soil quality which were cut off by dividing a construction area for every construction yard, work efficiency improves. In addition, by installing the soil improvement device in the construction yard, it is not necessary to use a surface soil or improved soil transport means such as a truck between the construction yard and the soil improvement device.

The soil improvement method according to the second aspect of the present invention is the soil improvement method according to the first aspect of the present invention, in which part or all of the improved soil whose soil quality has been improved by the soil improvement device is a cut-out surface soil. It is characterized in that it is substantially returned to its original location.
According to the second aspect of the present invention, surface soil having poor soil quality such as soft ground can be efficiently replaced with good quality improved soil. In addition, if it is not necessary to use all of the improved soil with improved soil quality to replace the surface soil that has been cut away, a part of it can be allocated to other uses.

The soil improvement method according to the third aspect of the present invention is the same as that of the first aspect of the present invention, wherein part or all of the improved soil whose soil quality has been improved by the soil improvement device requires another improved soil. It is transported to the area and reused.
According to the third aspect of the present invention, for example, when there is no need to return the improved soil to the construction area where the surface soil has been removed, or when there is an excess of improved soil, the improved soil can be effectively used. it can.

The soil improvement method according to a fourth aspect of the present invention is the soil improvement method according to any one of the first to third aspects of the present invention, wherein the soil improvement device is configured to add a solidifying material in a sealed pumping line, This is a line mixer capable of continuously performing mixing, stirring, and discharging.
According to the fourth aspect of the present invention, the use of a pipe mixer as the soil quality improvement device eliminates the scattering of the solidified material to be added, can prevent adverse effects on the surrounding environment, and reduces the loss rate of the solidified material. Therefore, the material cost can be reduced. In addition, when a pipe mixer is used, the surface soil and solidified material are sufficiently mixed, so a relatively compact system can be used to improve the soil quality in a large-scale, large-capacity construction area efficiently and in a short period of time. Thus, solidified materials having various properties can be used regardless of the purpose and application.

In the soil improvement method according to the fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, a soil collecting heavy machine such as a bulldozer or a scraper is used for cutting the surface soil. It is characterized by.
According to the fifth aspect of the present invention, the surface soil can be efficiently collected by using a soil collecting heavy machine such as a bulldozer that is superior in workability on soft ground than the stabilizer. The bulldozer can also be used as a means for transferring the replaced improved soil and for leveling.

In the soil improvement method according to the sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the cutting depth of the surface soil to be cut is within a range of about 30 to 60 cm. It is characterized by being set.
According to the sixth aspect of the present invention, since the cutting depth of the surface soil to be cut is shallow, for example, when a bulldozer is used, the blade is scraped to a predetermined depth in the surface soil to be cut. By simply advancing the bulldozer, you can scrape the surface soil and improve work efficiency.

The soil improvement method according to the seventh aspect of the present invention is the method according to any one of the first to sixth aspects of the present invention, wherein the surface soil removal and soil improvement in the construction yard unit are the necessary number of removal transfers. The present invention is characterized in that the apparatus and the single soil quality improvement apparatus are executed by being repeatedly used while being appropriately moved in accordance with the progress of the work.
According to the seventh aspect of the present invention, all the surface soil in the construction area is sequentially replaced with the improved soil in the construction yard unit by efficiently using the minimum necessary scraping and transferring device and the single soil quality improving device. can do. Therefore, the operating efficiency of the scraping transfer device and the soil quality improvement device is improved, and the equipment cost can be reduced.

  According to the present invention, it is possible to improve the soil quality of a large-scale, large-capacity construction area efficiently and in a short period of time with a relatively compact system, and to solidify various properties without depending on the purpose and application. It is possible to provide an economical soil improvement method that can add materials with high kneading efficiency without loss and can contribute to the improvement of high quality and stable soil quality.

  Hereinafter, the best mode for carrying out the soil improvement method according to the present invention will be described. In the following description, the construction of the mechanical equipment used for the execution of the soil improvement method of the present invention will be described first, and then the soil improvement construction method of the present invention executed by using the mechanical equipment in the section of the embodiment. Next, the results of comparative tests conducted to confirm the effects of the present invention are described in the section of comparison results, and finally, the configuration of the present invention in which the partial configurations are varied in the sections of other examples. Reference is made to other examples.

  FIG. 1 is a side view showing an example of the overall configuration of mechanical equipment used for carrying out the present invention, and FIG. 2 is a side sectional view showing an outline of a pipe mixer which is an example of a soil improvement device which is a part of the mechanical equipment. FIG. 3 is a plan view showing the construction area divided into construction yards, and FIG. 4 is an enlarged plan view showing one construction yard. FIG. 5 is a sectional side view showing a comparison of respective states of the construction area before soil improvement (a), at the time of cutting the surface soil (b), and after soil improvement (c).

  The machine equipment 1 used for carrying out the present invention includes a bulldozer 3 for accumulating a surface soil, which constitutes a scraping and transporting device 2 for cutting and collecting the surface soil H in the construction area A and transferring it to the soil quality improvement area C, and a soil quality improvement. The backhoes 6A and 6B for loading that constitute the scraping and transferring device 2 that inputs the surface soil H transferred to the area C to the soil quality improvement device 4, and the solidifying material K is added to the input surface soil H and stirred. The pipe mixer 5 which is an example of the soil quality improvement apparatus 4 which obtains the improved soil G by mixing and the scraping transfer apparatus 2 which transfers the improved soil G produced | generated by the pipe mixer 5 to the predetermined return position D are comprised. This is basically configured by including a backhoe 6C for transporting and an improved soil leveling bulldozer 7 constituting the scraping and transporting device 2 for leveling the improved soil G in the return position D. .

  As the bulldozer 3 for accumulation of surface soil and the bulldozer 7 for improved soil leveling, crawler type bulldozers can be used as an example used for various purposes such as leveling and earth filling. Various bulldozers for use in wetlands, ultra-wetlands, etc. can be used. The loading backhoes 6A and 6B and the transfer backhoe 6C can be crawler-type backhoes widely used as ground excavating devices. Various types of small to large types can be used depending on the processing capacity and application. Backhoe can be used.

  In this embodiment, the line mixer 5 includes a pressure-feed line 10 sealed as shown in FIG. 2, a stirring shaft 11 provided so as to penetrate the center of the pressure-feed line 10 along the longitudinal direction, and a stirring shaft 11. A spiral blade 12 provided integrally with the stirring shaft 11 on one end side of the outer periphery of the blade, a stirring blade 22 provided integrally with the stirring shaft 11 on the other end side following the spiral blade 12, and the center of the stirring shaft 11 in the longitudinal direction. The solidified material K inflow path 13 is formed by penetrating up to the vicinity of the boundary between the spiral blade 12 and the stirring blade 22. An injection port 13 a that is bent and extends toward the outer peripheral side of the stirring shaft 11 is provided at the end of the inflow passage 13. Further, in this embodiment, the stirring blade 22 is constituted by a plate-like body arranged in a cross shape. Further, the pressure feed line 10 is provided with an inlet 14 for introducing the cut-out surface soil H and an outlet 15 for discharging the generated improved soil G.

  Further, as shown in FIG. 1, a hopper 21 is provided above the input port 14 on the upstream side in the conveying direction of the pipe mixer 5, and the loading backhoes 6A and 6B are passed through the hopper 21. The surface soil H is input to the input port 14. Further, a generator 19 that supplies electric power to the pipe mixer 5 is provided in the vicinity of the pipe mixer 5.

  Further, in the vicinity of the pipe mixer 5, a silo 16 for storing the solidified material K, a solidified material feed feeder 17 for pumping the solidified material K in the silo 16 to the inflow path 13, and the solidified material pressure fed. A dry compressor 18 that supplies compressed air to the supply machine 17 and another generator 20 that supplies electric power to the solidified material pressure supply machine 17 are provided. As the solidifying material K, powdery solidifying materials such as cement and other lime-based solidifying materials, or those obtained by adding a hydrophobic agent, a flocking agent, a foaming agent, bentonite or the like to these can be used as examples. . Further, the properties of the solidifying material K are not limited to those in powder form, and various properties such as liquids and granules can be applied.

  In addition, in this embodiment, one end of two dust collecting pipes 23 is connected to the vicinity of the inlet 14 and the outlet 15 of the pipe mixer 5, and the other end of the dust collecting pipe 23 is It is connected to the dust collector 24. The mechanical equipment 1 such as the pipe mixer 5, the silo 16 and the solidified material feed feeder 17 installed in the soil improvement area C in this way prevents the sedimentation and inclination by placing the laying iron plate 25 on the soil improvement area C. Installed. In addition, when moving these mechanical equipment 1 etc. by work progress, it moves to the soil improvement area C in the next construction yard B using the crane etc. which are not shown in figure.

[Example]
Embodiments of the soil quality improvement method according to the present invention will be described in detail with reference to FIGS.
In the soil improvement method of the present invention, the construction area A where the surface soil H is scraped for improving the soil is divided into construction yards B having a predetermined unit area (1) a division process and a predetermined depth in units of the construction yard B The surface soil H is collected and transferred to the soil quality improvement area C where the pipe mixer 5 is installed. (2) The surface soil accumulation step, and the solidified material K is added to the accumulated surface soil H and mixed by stirring. (3) The soil quality improvement process which produces | generates improved soil by is fundamentally provided.

  In addition, in this embodiment, in addition to the above-described steps, (4) an improved soil return step is provided in which the surface soil H from which the generated improved soil has been scraped is substantially returned to the original place where the soil has existed (4). Is made up of. Hereinafter, the soil improvement method of the present invention will be described in detail by dividing into these steps.

(1) Sorting process (see Fig. 3)
In this step, the construction area A is divided into construction yards B as shown in FIG. In the illustrated embodiment, a rectangular construction area A having a width of 400 m and a depth of 500 m is taken as an example, and the construction area A is divided into rectangular construction yards B having a width of 50 m and a depth of 30 m. Depending on the width and depth dimensions of the construction area A or the shape of the construction area A, it may naturally occur that the construction yard B having the above shape and size cannot be secured, but in that case, the construction area A is classified into an appropriate shape and size. A separate construction yard B is provided.

(2) Surface soil accumulation process (see Fig. 4)
In this step, as an example, the surface soil H is scraped and collected using three bulldozers 3 for accumulating surface soil, and the ground soil H scraped toward the soil quality improvement area C is transferred. Then, the surface soil H transferred to the soil improvement area C is introduced into the hopper 21 by two backhoes 6A and 6B for loading as an example, and is introduced into the inlet 14 of the pipe mixer 5 through the hopper 21. Is done.

  In addition, the bulldozer 3 for accumulating surface soil is configured to sink the position of the blade 9 in the surface soil H by about 30 to 60 cm and drive the crawler while maintaining the amount of sedimentation (which is the cutting depth) S. And scrape up the surface soil H. The settling amount S of the blade 9 is appropriately adjusted according to the horsepower of the bulldozer and the state of the surface soil H. Accordingly, when cutting the hard surface soil H or the like that is difficult to cut, or when cutting a thick layer, the surface soil H is cut in multiple steps.

(3) Soil improvement process (see Figs. 1 and 2)
In this step, the surface soil H and the solidifying material K are mixed and stirred in the pressure-feed pipe 10 which is sealed by adding the solidifying material K to the surface soil H charged in the charging port 14, and is supplied to the downstream discharging port 15. The improved soil G generated is conveyed and discharged from the discharge port 15 to the outside of the pipe mixer 5. Specifically, the surface soil H is introduced into the pressure feeding line 10 from the inlet 14, and the solidified material K is formed on the upstream side of the agitation shaft 11 from the silo 16 through the solidified material pressure feeding machine 17 and enters the inflow path 13. In this way, the fuel is ejected from the ejection port 13a and guided into the pressure feeding line 10.

  Then, the surface soil H and the solidified material K supplied into the pressure feeding line 10 are agitated and mixed by the agitating blade 12 as the agitating shaft 11 rotates, and are sufficiently kneaded to improve the soil quality. And discharged from the discharge port 15. The discharged improved soil G is transferred to a predetermined return position D in the same construction yard B by a transfer backhoe 6C. Here, it is not always necessary to return the predetermined return position D to the original place where the surface soil H before the soil improvement existed, and the work efficiency in the same construction yard B is “good”. Any place that can be said.

(4) Improved soil return process (see FIGS. 4 and 5)
In this process, the improved soil G transferred to a predetermined return position D in the same construction yard B by the transfer backhoe 6C is leveled by the bulldozer 7 for leveling, leveled, and replaced with soil. I do. In this embodiment, the improved soil is uniformly leveled and leveled by two bulldozers 7 for leveling the improved soil.

  Therefore, as shown in FIG. 5 (a), the construction area A, which was initially covered with the surface soil H having a poor soil quality and difficult to use, was cut off as shown in FIG. 5 (b). The cut surface soil H is improved to improved soil G with good soil quality and replaced as shown in FIG. 5C, so that it can be used for various purposes and applications. And it was confirmed that the soil improvement method of this invention comprised in this way is excellent in various items compared with the conventional soil improvement method using a stabilizer, as shown in the following comparison results.

<Comparison result>
Table 1 below shows the comparison results between the conventional method and the main method when the modified soil is returned to the original position when the cutting depth S is 50 cm, and the improved soil is separated when the cutting depth S is 50 cm. Table 2 below shows the results of comparison between the conventional method and the present method when transported to the construction area that is the location of the above.

（１）条件
同一面積、同一形状の施工エリアＡを削取深さＳが５０ｃｍの場合で土質改良する場合のコスト、稼動効率、品質、安全性、施工性、自然環境への影響についてスタビライザーを使用した原位置撹拌方式の土質改良工法（以下従来工法という）と本発明の土質改良工法（以下本工法という）の差異を比較した。

(1) Conditions Stabilizer for the impact on the cost, operating efficiency, quality, safety, workability, and natural environment when soil quality is improved when the cutting area S is 50cm in the construction area A with the same area and shape. The difference between the in-situ stirring method soil improvement method (hereinafter referred to as conventional method) and the soil improvement method of the present invention (hereinafter referred to as method) was compared.

(2) Results and discussion (see Tables 1 and 2)
As shown in Tables 1 and 2, for all items, both when the improved soil is returned to its original position and the improved soil is transported to another construction area with a cutting depth S of 50 cm. This method was proved to be superior to the conventional method using a stabilizer. First of all, there are construction costs, temporary costs, and material costs. As for the temporary costs, there is a case where the main construction method may increase compared to the conventional construction method because the plant relocation work is required. The material cost can be greatly reduced, so the overall removal depth S is 50cm. When the improved soil is rolled back to the original position, it is about 15.3%, and the improved soil is transported to another construction area. In this case, the cost could be reduced by about 26%.

  The operating efficiency is calculated based on the actual number of working days. However, when the cutting depth S is 50cm, when the improved soil is rolled back to the original position, it is approximately 59%. An efficiency increase of about 60% was achieved in the case of transporting to the surface. Incidentally, improvement of soil quality in construction area A, where the actual operation days of the conventional method when the cutting depth S was 50 cm was 317 days, could be completed in 130 days in this process ((317 −130) / 317 ≒ 59%). In addition, by adopting the pipe mixer 5, the solidified material pressure feeding machine 17, and the like, the present method can perform kneading with high quality and stability, so that the soil quality can be improved uniformly and the quality is improved as compared with the conventional method.

  Moreover, since there is no scattering of the solidification material K in this construction method, it is not necessary to carry out dust curing or the like, and the surface soil H and the solidification material K are agitated by the agitating blades 12 provided in the sealed pressure-feed pipe line 10. Since it is mixed, the safety is improved compared to the conventional method. In addition, in this construction method, it is possible to continuously improve the soil quality at a high speed with good kneading efficiency with the solidifying material, and it is possible to greatly shorten the process and to improve the workability as compared with the conventional construction method. In addition, since there is no scattering of the solidifying material K in this construction method, the adverse effect of the solidifying material K on the surrounding environment can be prevented, and an environmentally-friendly cement-based solidifying material can be applied as the solidifying material K compared to the conventional construction method. The impact on the environment will be significantly reduced.

[Other embodiments]
The soil improvement method according to the present invention is based on the configuration as described above, but it is of course possible to change or omit the partial configuration without departing from the gist of the present invention. . For example, instead of returning to the original construction yard B where the surface soil H, where all of the improved soil G with improved soil quality had been removed, a part of the improved soil G was used for other purposes, It can be used to improve the soil quality of other construction yards B. It is also possible to transport a part or all of the improved soil G to another construction area A that requires the improved soil using a transporting means such as a truck and reuse it. Moreover, the number and kind of the mechanical equipment 1 to be used are not limited to those of the above-mentioned embodiment, and are appropriately adjusted according to the size and shape of the construction area A or the construction yard B, the soil condition, the planned construction period, and the like. It is possible.

  The present invention can be used, for example, in the construction site of a soil improvement method that replaces dredged soil etc. deposited on the bottom of rivers with soft and high water content with good quality soil, and is particularly economical and efficient in a short construction period. It can be used when you want to improve the soil quality by safely reducing the impact on the surrounding environment.

It is a side view showing the whole machine equipment composition used for execution of the present invention. It is a sectional side view which shows the outline | summary of the pipe mixer which is an example of the soil improvement apparatus which is a part of said mechanical installation. It is a top view which shows a mode that a construction area is divided for every construction yard. It is a top view which expands and shows one of the construction yards. It is a sectional side view which compares and shows each state of the construction area before soil improvement (a), at the time of cutting of surface soil (b), and after soil improvement (c).

Explanation of symbols

1 mechanical equipment, 2 scraping and transporting equipment, 3 bulldozers for soil accumulation
4 Soil improvement device, 5 pipeline mixer, 6A, 6B Backhoe for loading,
6C Backhoe for transport, 7 Bulldozer for improved soil leveling, 9 blades,
DESCRIPTION OF SYMBOLS 10 Pressure feed line, 11 Stirring shaft, 12 Spiral blade, 13 Inflow path, 13a Injection port
14 input port, 15 discharge port, 16 silo, 17 solidified material pressure feeder,
18 dry compressors, 19 generators, 20 generators, 21 hoppers,
22 stirring blades, 23 dust collection pipes, 24 dust collectors, 25 laid iron plates, A construction area,
B construction yard, C soil improvement area, D return position, H surface soil, G improved soil,
K Solidified material, S Cutting depth (sedimentation amount)

Claims (7)

  The construction area where the surface soil is cut to improve soil quality is divided into construction yards with a predetermined unit area, and the soil improvement device is installed by collecting the surface soil with a predetermined cutting depth in each construction yard. A soil improvement method that is transported to a soil improvement area in the construction yard to improve the soil quality.   2. The soil according to claim 1, wherein a part or all of the improved soil whose soil quality has been improved by the soil quality improving device is substantially returned to the original place where the cut surface soil existed. Soil improvement method.   2. The soil according to claim 1, wherein a part or all of the improved soil whose soil quality has been improved by the soil quality improving device is transported to another construction area that requires the improved soil and reused. Improved construction method.   The soil improvement device according to any one of claims 1 to 3, wherein the soil improvement device is a conduit mixer capable of continuously performing the addition of a solidifying material, mixing with a surface soil, stirring, and discharging in a sealed pumping conduit. Soil improvement method characterized by that.   5. The soil improvement method according to claim 1, wherein a soil collecting heavy machine such as a bulldozer or a scraper is used for cutting the surface soil.   The soil improvement method according to any one of claims 1 to 5, wherein a cutting depth of the surface soil to be cut is set in a range of about 30 to 60 cm.   In any one of Claims 1-6, the cutting of the surface soil and the improvement of soil quality of the said construction yard unit move suitably the cutting transfer apparatus of a required number, and a single soil improvement apparatus according to progress of work. A soil improvement method characterized by being carried out by repeated use.

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