WO2010059016A2

WO2010059016A2 - Construction method for improving soft ground

Info

Publication number: WO2010059016A2
Application number: PCT/KR2009/006947
Authority: WO
Inventors: 이인형; 이기현; 이기승; 이기준
Original assignee: 에이치엔티환경건설개발주식회사
Priority date: 2008-11-24
Filing date: 2009-11-24
Publication date: 2010-05-27
Also published as: WO2010059016A3

Abstract

A construction method for improving soft ground is disclosed. The present invention is implemented by initially drilling soft ground along a demarcated line, the stabilized soil is then layered to install a subterranean wall and a stabilized mat is formed over the subterranean wall. A displacement layer is next formed over the stabilized mat and gravel placed over the displacement layer. Cone-shaped stakes are installed according to previously positioned reinforced steel, then gravel is used to fill spaces around the cone-shaped stakes, and a finished layer is formed over the cone-shaped stakes. The present invention is a method for improving soft ground for construction which provides a support foundation for securing the pressure overload of a building structure and suppression of lateral deformation, which ensures economic and environmental benefits.

Description

Soft ground improvement method

The present invention relates to a method for improving the soft ground, and more particularly, the soft ground can secure the bearing capacity for the load of the required design structure in the ultra soft ground, suppress the lateral deformation, and secure economic and environmental properties. It is about improved construction method.

Ultra-soft ground is a ground that cannot support the superstructure. SPT (Standard Penetration), which is one of the representative tests for judging soft ground due to severe ground breakdown, excessive settlement and lateral deformation due to the load of the superstructure, and low shear strength. Test) It means the ground with weak bearing capacity with N value of 2 or less and qu (uniaxial compressive strength) value of 0.5 or less.

The soil that constitutes super soft ground is mainly soft clay, fine soil such as silt, organic soil, etc. Super soft ground is saturated ground with small strength, low compressibility and small permeability. Therefore, when the soil is excavated or excavated from the ground to the construction surface, it is difficult to run the equipment due to lack of required bearing capacity, ground subsidence, and lateral flow, so it takes a long time and severely destroys the ground. It is a ground to establish measures for improvement and reinforcement methods.

In order to improve the ultra soft ground, a method of forming a cylindrical or square wall or solid ground in the ground by using a cement hardening reaction while injecting a stabilizer mixed with cement-based injection material and water into the super soft ground. This has been used.

Specifically, it is constructed by stirring while injecting a stabilizer while lowering the excavator to an excavation depth within a short time, and injecting a stabilizer while drawing the excavator again.

On the other hand, the above-described method, which is commonly used for improving super soft ground, may generate voids in the ground by agitating the stirring blade several times while the stabilizer is injected into the ground, which lowers the strength of the ground. Can cause problems.

In addition, in the conventional case, cement is mainly used as a stabilizing material, and the cement contains a large amount of organic matter such as humic acid, which hinders mixing when mixed with soil of a landfill containing a large amount of organic material. The soft ground stabilization method using the conventional cement by preventing the bond with has a limit in improving the strength of the soft ground.

In addition, when used to reinforce the seabed or dredged landfill, by changing the environment by the strong alkalinity of cement, it can cause serious environmental problems, such as causing significant problems to the ecosystem, such as the growth and aquaculture of marine plants or organisms There was a problem.

Accordingly, it is an object of the present invention to provide a soft ground improvement method that can secure bearing capacity for required loads of design structures required in ultra soft ground, suppress lateral deformation, and secure economical and environmental performance.

Soft ground improvement method according to the present invention for achieving the above object, (a) installing the ground wall by excavating the soft ground in accordance with the display line displayed on the surface of the soft ground, and laying a solidified soil; (b) constructing a solidified soil mat on the installed underground wall; (c) constructing a substitution layer on the constructed solidified soil mat; (d) installing conical piles according to the reinforcement positions after laying the crushed stone on the constructed replacement layer; And (e) filling crushed stone around the installed conical piles and constructing a finishing layer on the installed conical piles.

Preferably, the step (a) further comprises the step of laying geotextiles after compacting the laid solidified soil.

In addition, the finishing layer in the step (e) is characterized in that the construction of a high soil soil mat.

In addition, after the step (c), further comprising the step of constructing a geotextile mat on the substitution layer.

In addition, the step (c) in the substitution layer is characterized in that a material mixed with soft soil and solidified soil excavated in the field as a substitution material is used.

In addition, the conical pile in the step (d) is characterized in that it is made of solidified soil.

According to the present invention, it is possible to construct the conical pile method in the super soft ground by increasing the strength of the super soft ground by the ground wall, the solidified soil mat, and the substitution layer in the super soft ground, which was impossible at all. It is effective.

In addition, according to the present invention, there is provided a soft ground improvement method that can secure the bearing capacity to the load of the required design structure in the ultra soft ground, suppress the lateral deformation, and secure economic and environmental properties. In addition, according to the present invention, when the groundwater level is high, it is recognized that the buoyancy function by the ground wall additionally acts.

In addition, according to the present invention, in the conventional soft ground by using only a large amount of cement independently caused a problem of contamination by strong alkalinity, in the present invention can effectively reduce the use of cement and significantly reduce the amount of cement by using a cement-based solidifying material By doing so, it is possible to solve the environmental pollution problem caused by strong alkalinity, and can significantly reduce the construction cost by significantly reducing the amount of aggregate.

In addition, according to the present invention, by using the site soil directly by the construction of the step of using a high-altitude soil, environmentally friendly effect is provided because it is possible to reduce the nature damage to use the soil or aggregate for landfill do.

1 is a view showing the ground structure to which the soft ground improvement method according to the present invention is applied,

2 is a flow chart illustrating a process of the soft ground improvement method according to the present invention;

3 is a view for explaining the detailed process of installing the underground wall in the present invention,

4 is a view for explaining a detailed process of constructing a high-fiber soil mat in the present invention, and

It is a figure explaining the detailed process of installing a cone pile in this invention.

Hereinafter, with reference to the drawings will be described the present invention in more detail. It should be noted that the same elements in the figures are represented by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a view showing the ground structure to which the soft ground improvement method according to the present invention is applied, Figure 2 is a flow chart illustrating the process of the soft ground improvement method according to the present invention.

Referring to Figures 1 and 2, when explaining the soft ground improvement method according to the present invention, first, the operator installs the underground wall 100 in the core of the soft ground to be improved (S210). In installing the underground wall 100, it would be desirable to provide a ground wall 100 made of solidified soil material, and the detailed process of installing such a ground wall 100 is shown in FIG.

Referring to FIG. 3, as shown in FIG. 3A, the operator displays a line indicating the position of the underground wall 100 to be constructed on the upper part of the soft ground to be improved. Then, as shown in (b), the worker excavates the underground wall 100 using heavy equipment according to the marking line, and the cemented soil is installed on the excavated underground wall 100 as shown in (c). Mixing and laying the mixed solidified soil in the excavated underground wall 100 as in (d).

When the installation of the solidified soil on the excavated underground wall 100 is completed, after the process of compacting the solidified soil underground wall 100 as in (e) using a compaction equipment such as a hand roller, finally (f) By laying geotextiles as in to complete the installation of the underground wall 100. As such, the underground wall 100 installed with the high-grade soil material forms a buoyancy base, not only prevents lateral flow, but also suppresses unequal sedimentation, exerts a ground stress reduction effect, and prevents liquefaction. About 10% of the floor load is distributed and burdened on the installed hardened soil ground wall 100.

When the underground wall 100 is installed through the above-described process, the worker constructs the high soil soil mat 110 on the installed underground wall 100 (S220). The detailed process of constructing the solidified soil mat 110 is shown in FIG. 4.

Referring to Figure 4, as can be seen in Figure 4 (a), the operator first mixes the solidified soil using heavy equipment, and after laying the solidified soil as in (b) and solidified by using the compaction equipment Through the process of compacting the soil, as shown in (d) on the solidified soil mat 110 formed as a result of the compaction, as shown in (d) by suppressing the settlement of the soft ground, and projecting protrusion By laying the type geotextiles, the frictional force can be increased. Thus, the installation of the Gohwa mat mat 110 foundation is completed to exhibit the required bearing capacity reinforcement effect, by improving the value of N, the strength constant of the foundation ground to 2 or more, to enable the construction of the subsequent cone-shaped pile 140 In addition, it functions to suppress settlement and deformation of the ground.

In addition, by dispersing the ground load of the foundation ground for the design load of the repair and building structure, the wide solidified soil mat 110 to increase the support load to perform a function to maintain the foundation stable. On the other hand, on the basis of the construction of the soil mat mat 110, about 25% of the load of the floor load is distributed and shared.

When the construction of the solidified soil mat 110 is completed through the process as described above, the worker constructs the substitution layer 120 which is an aggregate layer on the solidified soil mat 110 (S230). That is, the worker can prevent settlement and impact vibration of the ground through the substitution process using aggregates such as sand.

On the other hand, in the practice of the present invention may be used as a substitute material of good quality sand or soil, but may be mixed with the soft soil and solidified soil excavated in the field and recycled as a replacement material.

When the construction of the substitution layer 120 is completed, the worker may construct a geotextile mat 130 on the substitution layer 120 as necessary to further suppress the settlement (S240). Here, the worker may increase the friction by constructing the protrusion protrusion geo-fiber mat 130.

On the other hand, in carrying out the present invention, the worker may omit the construction process of the geotextile mat 130 in step S240 according to the ground survey test analysis results.

When the geotextile mat 130 is constructed, the worker installs a conical pile 140 on top of the substitution layer 120 in which the geotextile mat 130 is constructed (S250). The detailed process of installing the conical pile 140 is shown in FIG. 5.

Referring to Figure 5, as can be seen in Figure 5 (a), prior to installing the cone-shaped pile 140, the operator lays the crushed stone 145 (gravel) of approximately 25mm diameter. When the laying of the crushed stone 145 is completed, the position reinforcement 150 is arranged as in (b), and the conical pile 140 is installed in the position reinforcement 150 as in (c). After the installation of the conical pile 140 is completed, by filling the crushed stone 145 so that the conical pile 140 can be covered and cast concrete about 20 cm, the construction of the conical pile 140 layer is performed as in (d). Is done. Through the installation of the conical pile 140, it is possible to secure the load reduction effect on the floor load by the structure to be installed on the soft ground. Specifically, the conical pile 140 is to share the load of about 50% of the floor load.

In addition, in the practice of the present invention, the cone-shaped pile 140 may be made of solidified soil without using a conventional concrete material, and at the same time it may be possible to reduce the cost and environmentally friendly construction.

When the construction of the conical pile 140 layer is completed through the fixing as described above, the worker constructs the finishing layer 160 on the top of the conical pile 140 layer (S260).

In the construction of the finishing layer 160, it would be preferable to construct a high-fiber soil mat 110, and in the practice of the present invention, the finishing layer 160 may be constructed with a concrete slab, which is a general finishing layer 160. .

As a result, the construction of the soft ground improvement method according to the present invention is completed, and then the construction of the structure on the soft ground is possible through a process of constructing the direct foundation of the structure on the finishing layer 160.

Although the above has been shown and described with respect to preferred embodiments and applications of the present invention, the present invention is not limited to the specific embodiments and applications described above, the invention without departing from the gist of the invention claimed in the claims Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

The present invention has industrial applicability in connection with the field of geotechnical improvement methods in the field of civil engineering.

Claims

(a) excavating the soft ground according to the marking line displayed on the soft ground surface and installing the ground wall by laying solid soil;

(b) constructing a solidified soil mat on the installed underground wall;

(c) constructing a substitution layer on the constructed solidified soil mat;

(d) installing conical piles according to the reinforcement positions after laying the crushed stone on the constructed replacement layer; And

(e) filling crushed stone around the installed conical piles and constructing a finishing layer on the installed conical piles;

Soft ground improvement method comprising a.
The method of claim 1,

In step (a),

Soft ground improvement method further comprising the step of laying the ground fibers after the compacted solidified soil.
The method of claim 1,

The finishing layer in the step (e) is a soft ground improvement method that is to be constructed as a solidified soil mat.
The method of claim 1,

After step (c),

Soft ground improvement method further comprising the step of constructing a geotextile mat on the substitution layer.
The method of claim 1,

The soft ground improvement method of the (c) step is used as a substitute material of the soft earth and solidified soil excavated in the field as a replacement material.
The method of claim 1,

The conical pile in the step (d) is a soft ground improvement method that is made of solidified soil.