JP2003003476A - Earth filing method using cohesive soil having high moisture ratio - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an embankment such as a high standard bank at a relatively low cost by using soil improved by an improving method mixing a hardener from cohesive soil having a high moisture ratio such as sludge from construction work or spoil from rivers. SOLUTION: A sand or cobble-shaped high-grade improved and treated filling material hardened by adding or mixing an additive mainly comprising sludge from construction work or spoil from rivers is used for developing outer peripheral fills 2 surrounding the environment; and unimproved cohesive soil having a high moisture ratio or a low grade improved and treated filling material made by adding and mixing an additive mainly comprising a hardener to unimproved cohesive soil with a high moisture ratio for securing a predetermined strength at a desired time is filled to a portion surrounded by the outer peripheral embankment, and levee embankment can be achieved by hardening after the elapse of a desired curing period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a high water content cohesive soil for improving a high water content cohesive soil such as construction sludge or river dredged soil, and forming a bank for building a dike or land. Regarding the embankment method.

[0002]

2. Description of the Related Art Generally, when constructing a dike such as a high-standard dike, it is preferable to use the dredged soil that has been dredged from an adjacent river. Immediately after the dredging, even if the soil has a high water content ratio, it is dehydrated or added. It can be used as embankment embankment by improvement treatment such as adding material and solidifying treatment.

In the conventional improvement treatment of a high water content dredged soil, a riverbed is used as a dehydration treatment yard, and a dredged soil storage basin is constructed by surrounding embankments and the like, and the dredged soil of an adjacent river is put therein, and sun-dried. It is dehydrated by and dumped in a dump truck.

Further, conventionally, disposal of high-moisture specific cohesive soil caused by excavation of the ground using mud, such as shield tunnel excavation called construction sludge, has been a problem. Improvement methods are being investigated.

The method for improving the high water content specific viscosity soil such as the dredged soil and the construction sludge as described above is not limited to the sun drying, but the dehydration treatment, the solidification stabilization treatment, the firing treatment, the melting treatment, and the like are predetermined according to the purpose of use. Various methods have been proposed, from a low-quality improvement method for ensuring the strength of the steel to a high-quality improvement construction method that exhibits sandy and gravel-like shapes in a short period of time.

[0006] Above all, in the case of river dredged soil, since the amount of soil is large, relatively inexpensive improved construction methods such as sun drying and solidification treatment using a cement-based solidifying material are desired. Is the dehydration yard, which is then dried in the sun over a long period of time and then carried out.

[0007]

However, the above-mentioned conventional method of improving by sun drying requires a vast site and requires a long period of time for drying, during which the riverbed is filled with dredged soil. There is a problem in river safety. In addition, the improved soil after sun drying still has a high water content, and it can only be obtained in a solidified state where it can barely be carried out by a dump truck. There was a problem that processing was necessary.

In addition, the solidification treatment with cement-based solidifying material changes the addition amount of the solidifying material so that construction sludge of any water content can be treated in accordance with the "quality classification of treated soil as a soil material. And quality standard values "(quoted from" Construction Sludge Recycling Guidelines "issued by the Construction Technology Center of Japan) Since it is possible to create improved soils of Type 2 to Type 4 treated soils, it has been widely adopted so far. However, it requires a curing period and a curing yard to exhibit the prescribed strength, and because the treated soil becomes lumpy, it is difficult to handle because it needs to be crushed during effective use. Occurs. In addition, the conventional application standards of various treated soils shown in Table 1 are as shown in Tables 2 and 3 (quoted from "Construction Sludge Recycling Guidelines" issued by the Construction Technology Center).

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

[Table 3]

On the other hand, for the purpose of early use, the first in Table 1
In order to carry out high-quality improvements such as sand and gravel such as seed-treated soil, special improvement plants that require a heat source, such as firing treatment and melting treatment, were necessary. The improvement by these improved plants has very good performance of the improved soil created, and although it has a wide range of application as a civil engineering material,
Generally, the improvement cost is high, and it is not worth the cost as a method for producing relatively low quality improved soil such as embankment material. Furthermore, since it is difficult to make these improved plants portable, there is a problem in that they cannot easily meet the needs of the site where sludge treatment is difficult.

The present invention has been made in view of the conventional problems as described above.
It is a relatively low cost, and it is possible to create embankments such as high-standard embankments by using improved soil that has improved high water content ratio cohesive soil such as construction sludge and river dredged soil by an improvement method by mixing solidifying materials. It was made for the purpose of providing an embankment method using cohesive soil.

[0014]

The features of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose are as follows.
Create an outer peripheral embankment surrounded by high-quality improved embankment material in the form of sand or gravel that is solidified by adding and mixing an additive material mainly composed of solidifying material to high water content cohesive soil such as construction sludge or river dredged soil. Then, in the portion surrounded by the outer peripheral embankment, the unmodified high water content specific viscosity soil, or an additive material mainly composed of a solidifying material is added to and mixed with the high water content specific viscosity soil to obtain a predetermined strength at a desired time. Therefore, there is a method of embankment using high-moisture specific viscosity soil, which is characterized in that it is filled with a low-quality improved embankment material which has been improved so as to ensure the above, and is cured for a desired curing period.

According to the present invention, in the construction method having the above characteristics,
An embankment embankment is formed by stacking a plurality of layers of an embankment layer formed by filling an outer circumference embankment with a high-quality improved embankment material and filling the unsealed high-moisture specific viscosity soil or a low-quality improved embankment material in the outer embankment. Eggplants, high-quality improved embankment materials and low-quality improved embankment materials are additive materials to be added to and mixed with high-moisture specific viscosity soil, in addition to cement-based solidifying materials, gypsum, crushed waste paper, and / or other solidified materials. Using a mixture of auxiliaries, a high-quality improvement treated embankment material and a low-quality improvement treated embankment material, a mixer having a granulation function, a solidifying material adding device for metering and adding a solidifying material to the mixer, and the mixer. Manufactured using a high water content cohesive soil improvement plant having a solidification aid addition device for metering the solidification aid,
Bring the embankment to the embankment site and create an unmodified high-moisture specific viscosity clay or low-grade improved embankment material.
It is preferable to fill by pouring into the outer peripheral embankment before the fluidity disappears.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embankment constructed using the embankment method of the present invention. In the figure, reference numeral 1a is the first layer embankment, and 1b to 1d are the second to fourth layer embankments. It is soil. The embankments 1a to 1d of the respective layers each have an outer circumference embankment 2 constructed by high-quality improved soil in an arrangement surrounding the periphery in the outermost peripheral portion as shown in FIGS. 1 and 2, and are surrounded by the outer circumference embankment 2. An internal embankment 3 is formed by filling a portion with a low-quality improved embankment material.

The embankment formation of each of these layers is carried out by constructing the first layer embankment 1a and then stacking it on the second layer embankment 1b.
On top of this, the third layer embankment 1c and the fourth layer embankment 1d
Are built one after another.

For the embankment of each layer, for example, an improved treated embankment material obtained by improving the high water content specific viscosity soil using a high water content specific viscosity improvement plant as shown in FIG. 3 is used. This plant comprises a mixer 10, a cement-based solidifying material storage silo 11, and a solidification-aiding agent storage silo 12, which mixes and agitates a high water content cohesive soil consisting of river dredged soil or construction sludge with a cement-based solidifying material and various solidifying aids. Have, from both silos 11,12,
A necessary amount of the solidifying material and the solidifying aid can be introduced into the mixer 10 via the adding devices 11a and 12a, respectively.

Into the mixer 10, a high water content specific viscosity soil 14 such as river dredged sand carried by a soil carrier 13 is charged by using a hoisting device such as a backhoe 15 and a solidifying material to be added. By adjusting and adding the type and amount of the solidification aid, and kneading, various types of improved treated embankment materials can be obtained. The improved embankment material processed by the mixer 10 is discharged from the discharge port 16 at the bottom of the mixer and is loaded on the dump truck 18 by the conveyor 17.

In the mixer 10, as shown in FIG.
The central portion and the outer peripheral portion are provided with separate rotary stirring blades 19 and 20, respectively, and the rotation speeds of both stirring blades can be adjusted separately. It is configured so that it can also be made into grains.

As the cement-type solidifying material to be used, a commercially available cement-based solidifying material is used, and ordinary Portland cement, blast furnace cement B, solidifying material for general soft soil, solidifying material for high organic soil, gypsum and quick lime are used. Etc. are selected and used according to the water content of the dredged soil and the required degree of improvement of the improved embankment material.

As the crushed waste paper, for example, old newspapers and used telephone directories are preferably cut into a size of 20 mm square or less. Other solidification aids include natural and synthetic water-soluble polymers, Water absorbent resin is good. The polymer may be either a natural product or a synthetic product, and both may be used as a mixture.

As the high-quality improvement-treated embankment material used for the outer peripheral embankment 2, those having the same properties as those of the above-mentioned type 1 improved soil of Table 1 are used. This improved embankment material was prepared using the high water content cohesive soil improvement plant shown in FIG. 3 described above, using blast furnace cement B, soft soil solidifying material, high organic solidifying material or gypsum as solidifying material. The crushed waste paper and the polymer as a solidification aid are added to the high water content specific viscosity soil, kneaded, granulated and discharged, and the type of the solidification material, the mixing ratio of the solidification material and the additional material are adjusted. The quality of sand and gravel immediately after the improvement, that is, the degree to which it corresponds to the type 1 treated soil in Table 1 above, is used.

Further, as the low-grade improved treated embankment material,
A high-quality improved treated embankment material that uses the same amount of solidifying material and solidifying aid as the addition amount, or the time when it is necessary to use only the solidifying material or the solidifying aid and function as a fill, For example, at the scheduled start time of the work for stacking the next embankment layer or cover layer to be stacked above it, the cone index will be 4
The one adjusted to reach 00 kN / m2 is used.

Further, as the embankment material to be filled in the outer peripheral embankment 2, in addition to the above-mentioned low-quality improved treated embankment material, unmodified high-moisture specific viscosity soil may be directly filled, which has an embankment construction speed. It can be implemented when there is no problem even when the high moisture content cohesive soil is included in the sun drying period.

Among the above-mentioned improved or unimproved embankment materials, the high-quality improved embankment material has a sand / gravel shape immediately after the improvement treatment, so that when the construction site is close to the plant, a belt conveyor, etc. Can be used, and if relatively distant, a transportation means such as a dump truck or a soil carrier can be used.

Further, the conveyance of the low-grade improved embankment material is
When the corn index immediately after the improvement treatment by the plant has reached a level where trafficability can be secured,
It can be delivered to the site by the same transportation method as the high-quality improved embankment material.

In addition to this, in the case of the embankment material consisting of the low-grade improved treatment embankment material having high fluidity immediately after the improvement treatment and the unimproved high water content specific viscosity soil, as shown in FIG. Using the mechanical pumping device 21, the transport pipe 2
It may be sent to the construction site through 2. In this case, the part surrounded by the outer peripheral embankment 2 becomes a curing pond for solidification when the low-quality improved embankment material is used, and the sun-dried material when the unmodified embankment material is used. It will be an improvement pound.

Test Example Next, a test example in which various embankment materials are subjected to an improvement treatment using a high water content cohesive soil composed of river dredged soil will be described.

Table 4 shows the properties of the river dredged soil used in the test.

[0032]

[Table 4]

Using this river dredged soil, the property test results of the case where the solidified material and the solidification aid are selectively used by using the plant shown in FIG. It is shown in Table 5.

[0034]

[Table 5]

Description of test results No. 0 indicates the case of no treatment, and the strength is hardly exhibited even after 28 days have passed.

No. 1-9 shows the improvement result only by a solidification material. The improvement effect is large in the order of blast furnace cement B, ordinary Portland cement, soft clay solidifying material, and high organic solidifying material. Immediately after the improvement, only the solidified material has fluidity, and it is difficult to carry it by the dump truck and compact it. The corn index that can be transported is 200
It is ~ 400kN / m2, but if you try to exert this strength in one day, the strength in 28 days is 800k of the second type treated soil.
It is too large for N / m2. Further, the treated soil after improvement has a lump shape, and it is difficult to use it as it is as a civil engineering material such as embankment.

No. 10-No. No. 12 shows the case where a crushed material of waste paper or a polymer is used without using a solidifying material. When only the crushed waste paper of No. 10 is used, water absorption by the crushed waste paper progresses within a few minutes after the treatment, and the fluidity of the cohesive soil is significantly reduced. In this state, simple truck transportation is possible, but it is not so reusable as embankment.

No. When the crushed waste paper and polymer of No. 11 are used, the cohesive soil loses fluidity and becomes aggregated (not further granulated but completely lost fluidity). In this state, the soil is hydrophobized and the predetermined strength becomes very high. However, if it is compacted with a heavy machine, it will become mud again. It takes a considerable amount of time to dry until it can be compacted.

No. When only polymer No. 12 was used, the fluidity of the cohesive soil was significantly reduced, but it was not ready for reuse.

No. Nos. 13 to 22 show the cases where the solidifying material, the crushed waste paper and the polymer are used, and these are further granulated, and become sand / gravel. The grain strength can be adjusted by the amount of the solidifying agent added, which changes the curing period required for reuse. Depending on the type of solidifying material and the amount added, it can be used as embankment material immediately after improvement, and compaction work with a heavy machine is also possible.

[0041]

As described above, in the embankment method using the high water content specific viscosity soil according to the present invention, the additive material mainly composed of the solidifying material is added to the high water content specific viscosity soil such as construction sludge or river dredged soil. Create a peripheral embankment that surrounds the periphery with a high-quality improved treatment embankment material that exhibits mixed sand and gravel that is solidified, and in the portion surrounded by the peripheral embankment, the unmodified high water content specific viscosity soil,
Alternatively, a desired curing period is obtained by adding low-quality improved treated embankment material that has been subjected to improvement treatment to ensure a predetermined strength at a desired time by adding and mixing an additive material mainly composed of a solidifying material to the high water content specific viscosity soil. The embankment embankment can be used by placing it and hardening it, so that the embankment construction site can be used as a curing pond, and the conventional curing yard for sun drying and solidification is not required, and the embankment can be built early. it can.

Further, in the present invention, an embankment layer is formed by forming an outer peripheral embankment with a high-quality improved embankment material, and filling the outer peripheral embankment with an unimproved high water content specific viscosity soil or a low-quality improved embankment material. By constructing embankments in multiple layers to form an embankment embankment, it is possible to easily construct even a bulky high-standard embankment.

Further, in the present invention, a mixer having a granulation function, a high quality improvement treated embankment material and a low quality improvement treated embankment material, a solidifying material addition device for metering and adding a solidifying material to the mixer, and a solidification aid for the mixer. It is manufactured using a high water content cohesive soil improvement plant that has a solidification aid addition device that measures and adds the agent, and is brought to the embankment site to create the embankment. Since the improved treated soil can be obtained, the necessary embankment material can be obtained easily in accordance with the embankment construction process.

Further, according to the present invention, the unmodified high moisture content cohesive soil or the low-grade improved treated embankment material is poured into the outer peripheral embankment before its fluidity is lost, so that the material can be easily transported. Workability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an embankment constructed according to the present invention.

FIG. 2 is a plan view showing the process of building the embankment shown in FIG.

FIG. 3 is a schematic diagram of a high water content specific cohesive soil improvement plant used in the present invention.

FIG. 4 is a cross-sectional view of a mixer used in the above plant.

FIG. 5 is a schematic view of an example of a transportation facility used in the present invention.

[Explanation of symbols]

1a-1d embankment 2 Perimeter embankment 3 internal embankments 10 mixer 11 Cement-based solidifying material storage silo 11a addition device 12 Solidification aid storage silo 12a addition device 13 Earth Ship 14 High water content specific clay 15 backhoe 16 outlet 17 Conveyor 18 dump truck 19, 20 Rotating stirring blade 21 pumping device 22 Transport pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuo Nagatsu             2-8 Koraku, Bunkyo-ku, Tokyo Goyoken             Inside the corporation (72) Inventor Katsuhisa Abe             1-7-5 Hatagaya, Shibuya-ku, Tokyo Stocks             Company Ternite F-term (reference) 2D044 CA10                 4D059 AA09 BG00 BG03 BJ01 BK09                       CB09 CB19 CC10 DA06 DA66                       DB34

Claims (5)

[Claims] 1. A high-quality improved treated embankment material in the form of sand or gravel which is solidified by adding and mixing an additive material mainly composed of a solidifying material to a high water content cohesive soil such as construction sludge or river dredged soil. The surrounding embankment is formed, and in the portion surrounded by the peripheral embankment, the unmodified high water content specific viscosity soil or the high water content specific viscosity soil is added and mixed with an additive material mainly composed of a solidifying material to obtain a desired mixture. An embankment method using a high water content specific viscosity soil characterized by filling a low-grade improvement-treated embankment material that has been subjected to an improvement treatment so as to ensure a predetermined strength at a certain time, and curing the material for a desired curing period. 2. A multi-layered embankment layer formed by forming an outer peripheral embankment using a high-quality improved embankment material and filling the outer peripheral embankment with unmodified high water content specific viscosity soil or low-quality improved embankment material. The embankment method using the high water content specific viscosity soil according to claim 1, which is piled up to form an embankment. 3. The high-quality improvement treated embankment material and the low-quality improvement treated embankment material are cement-based solidifying materials, gypsum, crushed waste paper, and / or other materials as addition materials to be added to and mixed with high-moisture specific viscosity soil. The embankment method using the high water content specific viscosity soil according to claim 1 or 2, wherein a mixture of the solidification aid of (1) is used. 4. A mixer having a granulation function, a high-quality improved embankment material and a low-quality improved embankment material, a solidifying material addition device for metering and adding a solidifying material to the mixer, and a solidification aid for metering and adding to the mixer. The high water content specific viscosity soil produced by using the high water content specific viscosity soil improvement plant having a solidification aid adding device, which is brought into the embankment construction site to form the embankment, according to claim 1 or 2. Embankment method using water-containing cohesive soil. 5. The high water content according to claim 1, wherein the unmodified high water content specific viscosity soil or the low-quality improved treated embankment material is filled by pouring into the outer peripheral embankment before the fluidity thereof is lost. Embankment method using specific viscosity soil.