JPH11190019A - Creation method for soil-improved artificial ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent ground breaking when a large deformation is applied, by improving the deformation performance of soil improved artificial ground having a high peak strength. SOLUTION: A soil improved artificial ground G is created between a panel wall body and ground cut surface behind it. The soil improved artificial ground G can be created by placing artificial ground material 2 such as slender pieces of elastic materials such as rubber or urethane, waste tires or waste plastics, crushed pieces or waste such as waste paper or the like, or increased deformed materials 1 comprising these compounds together with artificial ground materials 2 mixed with solidifying material such as cement or the like and water mixed with adequate proportions. Reinforcing material such as wire netting SN are embedded at predetermined heights in the soil improved artificial ground G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving the deformation performance of various types of artificial ground having improved strength by adding a solidifying material such as cement.

[0002]

2. Description of the Related Art Soil-improved artificial ground is a soil cement-produced ground in which a solidifying material such as cement and water are stirred and mixed with the ground, and a soft embankment material mixed with a solidifying material such as cement and water. Or an improved ground formed by mixing a solidifying material such as cement and water with a soil material and further mixing a lightweight material such as air bubbles or styrene foam granules. And the peak strength (strength at the time of destruction by increasing the deformation load) of such a soil improvement artificial ground is remarkably improved compared to the normal ground consisting of only general soil, and the solidification material By appropriately adjusting the mixing ratio and the like, there is an advantage that the peak intensity can be arbitrarily set within a certain range.

However, the artificial ground with improved soil quality
It has been pointed out that there is a problem that the deformability is remarkably small as compared with the usual soil ground. That is, FIG. 6 shows the relationship between the strain ε and the strength σ when a deformation load is applied to the normal ground sample consisting only of general soil and the soil improvement artificial ground sample, and shows that the soil improvement artificial ground compared to the normal ground. of a remarkable large peak intensity sigma _max, the strain amount at the time of peak intensity sigma _max (fracture strain epsilon _f) is small, thus, for example greater strain than the fracture strain epsilon _f by an external force of subsidence or the like foundation ground When the soil is added, the strength of the artificial soil for improved soil rapidly decreases, and continuous cracks are generated, thereby destroying the ground. Also, when improving the deformability of the ground,
Although there is a method of mixing a chemical such as a thickening material, the thickening material itself is expensive, and remarkable improvement in deformability could not be expected.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made under the above circumstances, and its technical problem is to improve the deformation performance of a soil improvement artificial ground having a large peak strength. Therefore, it is an object of the present invention to effectively prevent ground failure when a large strain greater than the breaking strain is applied.

[0005]

Means for Solving the Problems The technical problems described above are:
This can be effectively solved by the present invention. That is, the method for forming the artificial soil for soil improvement according to the present invention has a property of adhering to the soil improvement material and a required elasticity and tensile strength when mixing the soil improvement material such as the solidified material into the soil material or the ground. Is mixed at an appropriate mixing ratio. In this case, the deformable material adheres to the soil improving material, and has the effect of three-dimensionally connecting and constraining the ground structure to increase its apparent shear resistance and tensile strength. Therefore, as shown by the broken line in FIG. 6 described above, the breaking strain corresponding to the peak strength σ _max is increased from the conventional ε _f to ε _f ′ to the same degree as the breaking strain of the normal soil ground. In addition, the deformation performance can be improved.

In the present invention, as the deformable material, an elongated strip of an elastic material such as rubber or urethane is preferably used. In this case, if the load that caused the distortion of the soil improvement artificial ground is removed, the soil improvement artificial ground is restored to its original shape. Further, as long as the material has the required elasticity and tensile strength, it is also preferable to use crushed pieces of waste such as waste tires, waste plastics, waste papers, and the like as the deformable material. In this case, the effective use of industrial waste and the like can be promoted, and the construction cost can be reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing an artificial soil improvement ground formed by a method according to an embodiment of the present invention. In FIG. 1, reference numeral B denotes a foundation ground, and G denotes an artificial soil improvement ground formed on the foundation ground B.

[0008] The artificial soil G for improving the soil is formed between a panel wall W, W, ..., which is constructed almost vertically, and a ground cut surface behind the panel wall W, W, W, .... Increasingly deformable material 1 consisting of fine pieces, crushed pieces of waste such as waste tires, waste plastics, waste paper, or composites thereof, and solidifying material such as cement and water are formed from locally generated soil and the like. It was created by casting an artificial ground material 2 mixed in an appropriate ratio with the embankment material. The panel walls W, W,... Are used for forming the soil improvement artificial ground G and protecting the wall surfaces thereof.
It is fixed by an anchor A projecting from the back and buried in the soil improvement artificial ground G.

[0009] Between the soil improvement artificial ground G and the foundation ground B, a water impermeable sheet I for blocking groundwater from the surrounding ground or the like.
S is interposed, and on the lowermost side of the soil improvement artificial ground G, in order to discharge excess infiltration water due to rainfall or the like, a drainage facility comprising sand with good drainability, a sand mat laid with sand or the like, or a blind drainage. D is provided. Further, in the portion of the foundation ground B where the lowermost panel wall W is arranged,
Discarded concrete BC is applied as necessary, and a wire mesh S is provided as needed at predetermined heights in the soil improvement artificial ground G.
A reinforcing material such as N is buried substantially horizontally.

[0010] Since the above-mentioned soil improvement artificial ground G has a ground structure in which soil particles are combined by a solidifying material, the peak strength is significantly higher than that of a normal ground made of only general soil. Further, in this soil improvement artificial ground G, the deformable material 1 mixed therein is fixed to the artificial ground material 2 by a solidifying material, and the ground structure is connected three-dimensionally.
Restraint increases the apparent shear resistance and tensile strength in the event that the bond by the solidified material is broken. For this reason, the soil-improved artificial ground G becomes more responsive when a large strain is applied due to an overhanging load, deformation occurring in the surrounding ground, or settlement of the foundation ground, and mixes chemicals such as a thickening material. It has higher deformation performance than the case. Reinforcing materials such as wire mesh SN buried at predetermined heights also have a function of connecting the ground structure in the horizontal direction and effectively preventing the occurrence of cracks.

Hereinafter, with reference to FIGS. 2 to 5, as an embodiment of the method for forming the artificial ground G for improvement of soil according to the present invention, the process of forming the artificial ground G for improving soil shown in FIG. I will explain later.

First, as shown in FIG. 2, cutting and leveling of the foundation ground G at the site where the soil improvement soil is to be formed, and drainage by laying a sand mat or the like on a predetermined area at the bottom of the foundation ground B. The equipment D is formed, and the stone is laid along the boundary on the front side, and the concrete BC is poured on it.
Further, a water impermeable sheet IS is laid from the upper surface of the drainage equipment D to the cut surface of the foundation ground G.

Next, as shown in FIG. 3, a plurality of panel walls W are arranged on a discarded concrete BC so as to be lined up in a row in a direction orthogonal to the cross section of the drawing. An anchor A made of a reinforcing bar or the like is integrally provided in advance on the back surface of the panel wall W formed of concrete or the like. Also,
When assembling the panel wall bodies W in a plurality of stages, the adjacent panel wall bodies W are connected to each other by a binding means or a mortar or the like as necessary. , Whereby the panel wall W
Firmly support.

Next, as shown in FIG. 4, the artificial space to an appropriate height is formed in a creation space defined between the assembled panel wall bodies W, W,. Ground material 2
And filling. At this time, the panel walls W, W, ...
Functions as a formwork for placing the artificial ground material 2, in other words, for forming the wall surface of the soil improvement artificial ground G. In addition, the artificial ground material 2 is obtained by solidifying the above-mentioned deformable material 1 and cement or the like to the soil material such as locally generated soil in a mixing facility (not shown) installed in the area adjacent to the site where the soil improvement artificial ground is to be formed. Material and water are mixed in an appropriate ratio.

Since the strength of the artificial ground material 2 that has been cast increases with time due to solidification of the solidified material, it is not necessary to perform compaction by a compaction roller or the like. The deformable material 1 in the artificial ground material 2 is integrally bonded to the ground structure of the artificial ground material 2 by a solidifying material that solidifies with time in the artificial ground material 2, and a three-dimensional structure for the ground structure is formed. A matrix-like constraining element is formed. The anchor A protruding from the back of each panel wall W is embedded and fixed in the artificial ground material 2 whose strength increases after casting, and the back of each panel wall W is The solidified material in the artificial ground material 2 that is in contact therewith is in a fixed state. Thereby, each panel wall W
Is integrated with the front of the soil improvement artificial ground G made of the artificial ground material 2.

As shown in FIG. 5, when the artificial ground material 2 is cast and filled to an appropriate height Δh, a wire mesh S
A reinforcing material such as N is laid, and an artificial ground material 2 is further laid thereon. And in this way, the artificial ground material 2
By repeating the required number of times of casting / filling and laying a reinforcing material such as a wire mesh SN thereon, an artificial ground for soil improvement as shown in FIG. 1 is created. After the construction is completed, the support 3 in front of the panel wall W is dismantled and removed.

In the above-described embodiment, a case has been described in which a material obtained by mixing a solidifying material such as cement and water in an appropriate ratio with an earth material such as locally generated soil is used as the artificial ground material 2. The present invention is also applicable to a case where a solidifying material such as cement is mixed with a ground or soft embankment material as a powder or in a slurry state, and compaction by a rolling roller or the like is required at the time of formation. Also, the panel wall W,
Reinforcing materials such as the impermeable sheet IS, the drainage equipment D, and the wire mesh SN may be provided as necessary, such as the situation at the construction site. In this case, a reinforcing material made of a polymer material having a required tensile strength can be used in addition to the wire mesh SN.

[0018]

According to the method for constructing an artificial soil improvement ground according to the present invention, the apparent tensile strength and shear strength when a deformation larger than the breaking strain is applied are increased, so that cracks are continuously spread. By using industrial waste as the deformable material, it is possible to simultaneously treat industrial waste and reduce construction costs.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a soil improvement artificial ground created by a method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing steps such as ground preparation of a foundation ground and formation of a drainage facility in creation of an artificial ground for soil improvement according to the embodiment.

FIG. 3 is an explanatory view showing a step of assembling a plurality of panel walls in the construction of the soil improvement artificial ground according to the embodiment.

FIG. 4 is a diagram showing an example of the construction of the soil improvement artificial ground according to the embodiment, in which an embankment mixture of a deformable material and a solidified material is poured between a panel wall and a ground cut surface behind the panel wall;
It is explanatory drawing which shows the process of filling.

FIG. 5 is an explanatory view showing a step of interposing a reinforcing material in a poured embankment material in creating the soil improvement artificial ground according to the embodiment.

FIG. 6 is an explanatory diagram showing the relationship between strain ε and strength σ when a deformation load is applied to a ground sample.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Increasing deformation material 2 Embankment material B Foundation ground G Soil improvement artificial ground

Claims (3)

[Claims] In the construction of an artificial soil improvement ground in which a soil improvement material such as a solidified material is mixed, when the soil improvement material is mixed with the soil material or the ground, the soil improvement material has a bonding property with the soil improvement material. A method for forming an artificial ground for improving soil properties, comprising mixing a deformable material having required elasticity and tensile strength at an appropriate mixing ratio. 2. The method according to claim 1, wherein an elongated strip of an elastic material such as rubber or urethane is used as the deformable material. 3. The method according to claim 1, wherein a crushed piece of waste such as waste tire, waste plastic, waste paper or the like is used as the deformable material. .