KR20110002175A - Lightweight material mounding structure and method for constructing the same - Google Patents

Abstract

PURPOSE: A lightweight material banking structure and a construction method thereof are provided to prevent problems, such as civil appeals and the subsidence of neighboring structures, caused by changes in underground water level. CONSTITUTION: A lightweight material banking structure comprises a base layer(30), a lightweight material layer(40), and a banking layer(50). The base layer is formed of a material having a greater specific gravity and less permeability than the water and installed with a part thereof located under the level of subsurface water(60). The lightweight material layer is built on the base layer. The banking layer is formed to surround the lightweight material layer between the base layer and the lightweight material layer. The lightweight material layer includes an intermediate banking layer which is formed of a material having a greater specific gravity and less permeability than the water.

Description

Lightweight material mounding structure and method for constructing the same}

The present invention relates to a fill structure and a construction method thereof, which are formed by using a lightweight material in filling the soft ground, particularly in a fill structure and fill method that can improve the stability to buoyancy in soft ground fill construction It is about.

Conventionally, ground improvement methods such as dewatering and compaction methods have been generally used in the construction of a place where the ground is very soft. When this method is used, there is a problem of accompanying settlement where adjacent ground adjacent to the soft ground sinks together with the soft ground. Occurred. Therefore, in order to solve this problem, the development of a landfill method using a lightweight material is actively progressing.

Styrofoam or expanded polystyrene (EPS) blocks are currently used as lightweight materials that are widely used. In particular, in the case of EPS blocks, due to the convenience of construction and excellent material properties, they are widely used for soft ground fill work. In order to reduce the load on the ground as much as possible, the landfill method using lightweight materials is first carried out by excavating the ground surface of the soft ground to be filled to a certain depth, replacing the excavated part with EPS blocks, and then performing the earthwork. In some cases, it may be constructed without ground improvement.

1 is a view showing a cross section of a conventional lightweight material fill structure. As shown in Fig. 1, the conventional lightweight material fill structure 1 excavates a portion of the soft ground 2, and has a structure in which the EPS block 3 is enclosed in the excavated portion. A portion of the EPS block 3 is located at a position lower than the water level H of the groundwater 5 of the soft ground 2, as shown in FIG. A cover layer 4 made of general earth and sand is formed on the EPS block 3. As a part of the EPS block 3 is located at a position lower than the groundwater level of the soft ground 2, the buoyancy B caused by the groundwater 5 is applied to the EPS block 3. On the other hand, the cover layer 4 formed of earth and sand is deposited on the EPS block 3, the load (P1) of the cover layer 4 is also applied to the EPS block (3). The buoyancy B and the upper load P1 due to the cover layer 4 act as a stress on the EPS block 3.

As such, when the EPS block 3 is constructed immediately after excavating a part of the ground surface of the soft ground 2, additional stress due to buoyancy is generated in the EPS block 3, and the allowable stress of the constructed EPS block 3 is reduced. Excessive problems can arise.

In particular, in the conventional case, in order to prevent the stability of the fill structure from deteriorating as the buoyancy force is applied to the EPS block 3 to rise to a predetermined height, the upper portion of the EPS block 3 is prevented. In some cases, there is a method of increasing the fixed load of soil deposited in the EPS block 3. In this case, when the fixed load of the soil deposited in the EPS block 3 is increased, long-term creep occurs in the EPS block 3. There is this.

2A and 2B are diagrams showing strain rates according to elapsed days of specifications of EPS blocks. 2A is the strain of the EPS D-25 block, and FIG. 2B is the strain of the EPS D-30 block. Where D represents the density, and EPS blocks are sized based on this density. As shown in FIGS. 2A and 2B, the EPS blocks gradually increase in the strain rate according to the elapsed days as the reloading pressure increases. Therefore, in the case of increasing the fixed load of the soil piled up, if the time of about one year after the construction of the EPS block (3) may cause a significant level of deformation occurs.

In addition, in the related art, in order to solve the problem of injuries of the EPS block 3, a construction method such as installation after installing a separate order wall is also proposed, but in the case of such a construction method, an additional process is added to the air. There is a problem that delays, unnecessary construction cost, and the method of filling the soil after draining the groundwater to a certain level is used. In the case of the groundwater drainage method, the groundwater level of the adjacent farmland is lowered and civil complaints Occurs, there is a problem that the adjacent structure is settled.

An object of the present invention is to solve the problems of the prior art as described above, by preventing the increase in the stress applied to the EPS block due to the buoyancy applied by the groundwater and at the same time does not cause fluctuations in the groundwater level It does not cause problems such as civil complaints and settlement of adjacent structures, and provides a light weight material fill structure and construction method thereof that are stable against penetration of groundwater or rainwater.

In order to solve the above problems, the light-weight material fill structure according to the present invention, part of which is installed at a position lower than the groundwater level, the base layer formed of a material having a higher specific gravity and lower permeability than water and the fill layer on the base layer It characterized in that it comprises a lightweight material layer. A cover layer may be formed on the lightweight material layer to surround it, and an intermediate cover layer formed of a material having a higher specific gravity and lower permeability than water may be further formed between the lightweight material layer and the cover layer. In this case, the materials forming the intermediate cover layer and the base layer may be the same material or may be different materials.

Specifically, the material for forming the base layer has a water permeability of 1 × 10 ^-4 cm / sec or less after construction, specific gravity of 1.1 ~ 2.0 tf / ㎥, uniaxial compressive strength after construction 1 ~ 10 kgf / ㎠ It is preferable that the fluidity is 100 to 300 mm, and the material for forming the intermediate cover layer has a water permeability of 1 × 10 ^-4 cm / sec or less after construction, a specific gravity of 0.5 to 1.5 tf / m3, and a uniaxial compressive strength after construction. It is 1-10 kgf / cm <2>, and it is preferable that fluidity is 100-300 mm.

On the other hand, the base layer and the intermediate cover layer is preferably formed of at least any one of the light-bubble mixed soil, light-bubble concrete, bubble mortar, fluidized soil, and the soil cement. In addition, the lightweight material layer is preferably an EPS block layer formed of a plurality of EPS blocks. Meanwhile, a waterproof member may be formed at a seam between the plurality of EPS blocks forming the EPS block layer to prevent leakage from an upper part of the EPS block layer.

Light weight material fill structure construction method according to the present invention comprises the steps of constructing a base layer formed of a material having a higher specific gravity than the water and a low permeability at a lower position than the groundwater level, and after the base layer is solidified a lightweight material layer on the base layer Characterized in that it comprises the step of filling.

In addition, the light weight material fill structure construction method according to the present invention further comprises the step of covering the cover layer on the light material layer upper layer, before the step of filling the cover layer, the intermediate is formed of a material having a higher specific gravity and lower permeability than water The method may further include depositing a cover layer to surround the light weight material layer.

In addition, before the covering of the cover layer, the method may further include installing a waterproof member on the joint portion of the plurality of EPS blocks forming the lightweight material layer.

According to the lightweight material fill structure and the construction method thereof according to the present invention, it is possible to reduce the stress applied to the EPS block used as the lightweight material, thereby enabling construction using the EPS block with a low allowable stress, thereby reducing the material cost. Can be saved.

In addition, it is possible to implement a stable fill structure by blocking groundwater or rainwater infiltration, and it is possible to construct a fill structure without unnecessary drainage of the groundwater, thereby minimizing civil complaints or settlement of adjacent ground due to groundwater level fluctuations.

Hereinafter, with reference to the accompanying drawings, will be described in more detail with reference to the embodiment of the lightweight material fill structure and its construction method.

The present invention is not limited to the contents of the embodiments described below, and various modifications can be made without departing from the technical gist of the present invention.

In addition, in describing the embodiments, descriptions of technical contents which are widely known in the technical field to which the present invention belongs and are not directly related to the technical gist of the present invention will be omitted. In the accompanying drawings, some components may be exaggerated, omitted, or schematically illustrated. This is to clarify the gist of the present invention by omitting unnecessary description that is not related to the gist of the present invention.

3 is a cross-sectional view of the lightweight material fill structure according to an embodiment of the present invention.

As shown in FIG. 3, the light-weight material fill structure 10 according to the present invention excavates a portion of the soft ground 20, and then has a portion corresponding to the water level lower than the water level H of the groundwater 60. It has a structure in which the base layer 30 is formed of a material having a high specific gravity and a low permeability.

Specifically, the base layer 30 is preferably formed of any one of a material such as lightweight foam mixed soil, lightweight foam concrete, foam mortar, fluidized soil, or cement to be fired, all of these materials have a specific gravity greater than water, The materials are very low or impermeable. In addition, all of these materials are lighter than general earth and sand, and thus are suitable materials for laying on soft ground. As the base layer 30 is formed of a material having a very low permeability, the groundwater 60 does not penetrate into the lightweight material layer 40 to be deposited on the base layer 30.

In the lightweight material fill structure 10 according to the present invention, the buoyancy U due to the groundwater 60 is applied to the base layer 30 formed of a material having a very low or impermeable water as described above. Buoyancy is not applied to the lightweight material layer 40 deposited on the base layer 30. The base layer 30 is embossed to have a thickness such that buoyancy is not applied to the lightweight material layer 40. When the foundation layer 30 is filled with a predetermined thickness, a part of the foundation layer 30 is constructed below the groundwater level H, and the buoyancy force U is thus located below the groundwater level H. Proportional to the volume. Meanwhile, since the specific gravity of the base layer 30 is greater than that of the lightweight material layer 40, the size of the buoyancy U actually generated may be greater than that of the conventional lightweight material fill structure 1 shown in FIG. 1. However, in the case of the light material fill structure 10 according to the present invention, unlike the conventional light material fill structure 1, the buoyancy force U is not directly applied to the light material layer 40, but to the base layer 30. Since it is applied, the stress applied according to the buoyancy U is largely solved by the base layer 30 and does not affect the light weight material layer 40. The fill thickness of the foundation layer 30 is appropriately determined according to the construction site. In consideration of the characteristics of the construction site, that is, the groundwater level, the foundation layer 30 is configured to minimize the influence of the buoyancy stress on the lightweight material layer 40. Determine the thickness of 30) and install.

On the other hand, as shown in Figure 3, the base layer 30 is preferably deposited in a form that completely surrounds the lightweight material layer 40 at a portion at least lower than the groundwater level (H). When the base layer 30 is filled to completely surround the lightweight material layer 40, groundwater may be prevented from entering the lightweight material layer 40. However, in the case of the base layer 30, the weight acting on the soft ground 20 is greater than the light weight material layer 40 in that the specific gravity is larger than the light weight material layer 40, in consideration of this point the soft ground 20 It is necessary to fill the foundation layer 30 with a suitable thickness to prevent the groundwater inflow while minimizing the increase in the load acting on the).

The materials forming the base layer 30 of the lightweight material fill structure according to the present invention have a water permeability of 1 × 10 ^-4 cm / sec or less after construction, specific gravity of 1.1 to 2.0 tf / m 3, and uniaxial compressive strength after construction It is 1-10 kgf / cm <2>, and it is preferable that fluidity is 100-300 mm. In order to implement the effect of the present invention, it is necessary to make the base layer 30 satisfy such characteristics. These properties can be obtained through a predetermined control process in the manufacture of lightweight foam mixture soil, lightweight foam concrete, foam mortar, fluidized soil, or fired cement. The contents related to the adjustment of the material properties are not directly related to the gist of the present invention, and description thereof will be omitted.

Lightweight material layer 40 is deposited on the base layer 30, the lightweight material layer 40 may be constructed of a plurality of styrofoam blocks or EPS blocks. EPS blocks are used according to the requirements of the construction site. According to the light weight material fill structure 10 according to the present invention, since the magnitude of stress applied to the EPS block forming the light weight material layer 40 is reduced, a light weight material fill structure is constructed using a cheaper EPS block. can do. For example, in the conventional lightweight material fill structure 1 shown in FIG. 1, the allowable compressive stress value and the repetitive load value applied to the EPS block are increased due to the stress caused by buoyancy force applied to the EPS block. As shown in Table 1 below, the size of the EPS block is determined according to the allowable compressive stress and the repetitive load value, and as the allowable compressive stress value and the repetitive load value increase, the standard value of the EPS block also increases.

TABLE 1

EPS Type Unit weight (tf / m ³ ) Allowable compressive stress (tf / m ² ) Allowable compressive stress 1% Allowable compressive stress 5% Cyclic load D-20 0.020 5 10 4.0 D-25 0.025 7 14 5.6 D-30 0.030 9 18 7.2

In the conventional lightweight material fill structure (1), due to the presence of additional stress generation factors due to buoyancy, etc., the lightweight material fill structure was constructed using D-25 or D-30 having a large allowable compressive stress and a repetitive load value. In contrast, in the light-weight material fill structure 10 according to the present invention, since there is no stress generated by buoyancy, EPS blocks having a lower allowable compressive stress and repetitive load value than the conventional case, for example, D-20 standard. EPS blocks can be used. As the material cost of the EPS block increases as the EPS standard value increases, the lightweight material fill structure 10 according to the present invention can significantly reduce the overall construction cost as compared with the conventional case.

On the other hand, the cover layer 50 formed of the earth and sand finally is deposited on the light material layer 40. The cover layer 50 is a top layer of the lightweight material fill structure 10 according to the present invention. When the soft ground is constructed as a road, the cover layer 50 is paved with a road. The cover layer 50 is filled to surround the lightweight material layer 40 as shown in FIG. 3. Before forming the cover layer 50 on the light weight material layer 40, a waterproof member for preventing leakage from the top of the EPS block layer on the seam portion between the plurality of EPS blocks forming the light weight material layer 40 ( Not shown) may be formed. As the waterproof member, any member can be used as long as it is a member capable of providing a waterproof effect by filling a gap, and for example, a waterproof tape may be used.

4 is a view showing a cross section of a modification of the lightweight material fill structure according to the present invention.

One modified example 100 of the light weight material fill structure according to the present invention shown in FIG. 4 is a structure in which an intermediate cover layer 600 is further provided between the light weight material layer 400 and the cover layer 500. The portion other than that the intermediate cover layer 600 is further formed is the same as the lightweight material fill structure 10 shown in FIG. That is, in one modification 100 of the lightweight material fill structure shown in FIG. 4, a portion of the lightweight material fill structure 100 is deposited on the base layer 300 and the base layer 300, which are partially deposited at a position lower than the water level H. The lightweight material layer 400, the intermediate cover layer 600 disposed to surround the lightweight material layer 400 on the upper portion of the lightweight material layer 400, and the cover layer 500 deposited on the intermediate cover layer 600 are disposed. The base layer 300, the lightweight material layer 400, and the cover layer 500 are the same as those formed in the embodiment 10 of the lightweight fill structure shown in FIG. 3, which will be described below. Omit.

The intermediate cover layer 600 is formed of a material having a specific gravity greater than water and having a low permeability or an impermeability similar to the base layer 300. That is, the intermediate cover layer 600 is formed of any one material, such as lightweight foam mixed soil, lightweight foamed concrete, foam mortar, fluidized soil, or soil cement, similar to the foundation layer 30 of FIG. It may be formed of the same material as the layer 300, or may be formed of a material having different properties. That is, the characteristics such as water permeability, uniaxial strength after construction, and fluidity have the same range as those of the values described in the description of the base layer 30 shown in FIG. Materials of ˜1.5 tf / m 3 may be used. In the case of the intermediate cover layer 600, which is a material deposited on the light material layer 400, it may be preferable that the intermediate cover layer 600 may be formed of a material having a small specific gravity.

Such intermediate cover layer 600 prevents rainwater from flowing into the lightweight material layer 400 after construction. That is, in the light weight material fill structure 100 according to the modification of the present invention, the intermediate cover layer 600 is further constructed, so that the light weight material layer 400 is completely enclosed with the base layer 300. At 400, the likelihood of inflow of groundwater or rainwater drops significantly.

On the other hand, when constructing such intermediate cover layer 600, it is possible to implement an effect that can reduce the upper load somewhat than when forming the cover layer 50 by using the general soil. The intermediate cover layer 600 may be formed of light mixed foamed soil, light foamed concrete, foam mortar, fluidized soil, or a fired cement, and these materials are materials having a lower load than the general soil, and thus cover all the soil layer. The upper load can be reduced rather than the case.

As such, the lightweight material fill structure 10 and 100 according to the present invention reduces the stress applied to the lightweight material layers 40 and 400 by preventing the buoyancy force applied by the groundwater from directly reaching the lightweight material layers 40 and 400. You can.

1 is a cross-sectional view of a lightweight material fill structure according to the prior art.

2A and 2B are diagrams illustrating strain rates according to elapsed days of specifications of EPS blocks.

3 is a cross-sectional view of the lightweight material fill structure according to an embodiment of the present invention.

4 is a cross-sectional view of the lightweight material fill structure according to a modification of the present invention.

Claims (19)

A base part formed at a position lower than the groundwater level and formed of a material having a higher specific gravity and lower permeability than water; And Lightweight material fill structure comprising a; a light material layer to be deposited on the base layer. The lightweight material fill structure of claim 1, further comprising a cover layer formed to surround the layer of lightweight material. The light weight material according to claim 2, further comprising an intermediate cover layer formed to surround the light weight material layer between the light weight material layer and the cover layer, and formed of a material having a specific gravity greater than water and low permeability. Fill structure. 4. The lightweight material fill structure of claim 3, wherein the intermediate cover layer is formed of the same material as the base layer. 2. The lightweight material fill structure of claim 1, wherein the foundation layer is formed to surround a portion of the layer of lightweight material at a location below the groundwater level. The material forming the base layer has a water permeability of 1 × 10 ⁻⁴ cm / sec or less after construction, specific gravity of 1.1 to 2.0 tf / m 3, and uniaxial compressive strength of 1 to 10 kgf after construction. Light-weight material fill structure, / cm2, characterized in that the fluidity is 100 ~ 300mm. According to claim 3, The material forming the intermediate cover layer has a water permeability of 1 × 10 ^-4 cm / sec or less after construction, specific gravity of 0.5 ~ 1.5 tf / ㎥, uniaxial compressive strength after construction 1 ~ 10kgf / Light-weight material fill structure, having a cm 2, fluidity of 100 ~ 300mm. 8. The light-weight material fill structure according to any one of claims 1 to 7, wherein the base layer is formed of at least one of light-bubble mixed soil, light-bubble concrete, foam mortar, fluidized soil, and soil cement. 4. The light-weight material fill structure according to claim 3, wherein the intermediate cover layer is formed of at least one of light-bubble mixed soil, light-bubble concrete, bubble mortar, fluidized soil and soil cement. The lightweight material fill structure according to any one of claims 1 to 7, wherein the lightweight material layer is an EPS block layer formed of a plurality of EPS blocks. The lightweight material fill structure of claim 10, wherein a waterproof member is formed at a seam between the plurality of EPS blocks forming the EPS block layer to prevent leakage from an upper portion of the EPS block layer. Constructing a base layer formed of a material having a higher specific gravity and lower permeability than water at a position lower than the groundwater level; And And filling the lightweight material layer on the foundation layer after the foundation layer is solidified. 13. The method of claim 12, further comprising depositing a cover layer on top of the lightweight material layer. The method of claim 13, further comprising, before the step of covering the cover layer, the intermediate cover layer formed of a material having a higher specific gravity and lower permeability than water to cover the lightweight material layer further comprises a light weight. Material fill structure construction method. The method of claim 13, wherein the lightweight material layer is formed of a plurality of EPS blocks. 16. The method of claim 15, further comprising installing a waterproof member at a seam portion of the plurality of EPS blocks before the covering of the cover layer. 13. The method of claim 12, wherein constructing the foundation layer comprises forming the foundation layer to surround a portion of the lightweight material layer at or below the groundwater level. The method of claim 12, wherein the base layer has a water permeability of 1 ~ 10-4cm / sec or less after construction, specific gravity 1.1 ~ 2.0 tf / ㎥, uniaxial compressive strength after construction 1 ~ 10kgf / ㎠, fluidity A lightweight material fill structure construction method, characterized by being formed of a material of 100 to 300 mm. The method of claim 12, wherein the intermediate cover layer has a water permeability of 1 공 10 -4cm / sec or less after construction, specific gravity of 0.5 ~ 1.5 tf / ㎥, uniaxial compressive strength after construction of 1 ~ 10 kgf / ㎠, Light weight material fill structure construction method characterized in that the fluidity is formed of a material of 100 ~ 300mm.

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