KR20210007553A - Soft ground improvement method using a stone bag - Google Patents

Abstract

Provided is a soft ground improvement method using stone bags. The soft ground improvement method using the stone bags comprises the following steps of: hardening and flattening a surface of the original ground; forming a first mat layer by paving at least one first mat on the original ground; forming a stone bag layer having a predetermined height by aligning and arranging a plurality of stone bags in which aggregates are contained in a mesh on the first mat; forming an improvement layer by filling a gap between the stone bags adjacent to each other and a gap between the aggregates contained in the stone bags with fillers having a particle size relatively smaller than that of the aggregates and paving the fillers on the stone bag layer so that the plurality of stone bags are entirely covered; and forming a second mat layer by paving a second mat on the improvement layer. Therefore, the soft ground improvement method using the stone bags can shorten a construction period.

Description

Soft ground improvement method using a stone bag}

The present invention relates to a construction method for improving soft ground by using a stone bag, and more particularly, it is eco-friendly because it is possible to increase the ground strength by using a stone bag containing an aggregate that is easy to secure materials. The present invention relates to a method of improving soft ground using a stoneback that is easy to construct and can shorten the construction period and reduce the overall construction cost.

In general, soft ground refers to a ground in a state where it cannot support the upper structure, and it has severe ground destruction, excessive subsidence, and lateral deformation, and its shear strength is small, meaning that the bearing capacity is weak with an N value of 2 or less and a qu value of 2 or less.

The soil that constitutes such a soft ground is mainly soft clay, fine-grained soil such as silt, and organic soil, and the soft ground is a saturated ground with low strength, high compressibility, and low permeability. Therefore, in the case of embedding or excavation from the ground to the construction surface, it is difficult to drive the equipment because the required bearing capacity is insufficient, ground subsidence and lateral flow occur, which takes a long time and causes severe ground destruction. This is the ground for which it is desired to establish measures for ground improvement and reinforcement methods.

In general, as a method of improving soft ground, preloading has been used in the ground on which vertical drainage materials such as PBD, sand drain, and pack drain are installed in order to promote consolidation drainage.

However, even if the strength of the soft ground is increased, it is not possible to completely avoid the occurrence of sub-friction of the foundation due to long-term consolidation, but damage to the structure due to secondary compression and subsidence, and even if the strength of the ground is increased by consolidation drainage method However, if the load of the structure is large, a foundation system should be additionally introduced to prevent the destruction of the ground. To this end, a substitution method, a mixing treatment method, and a pile foundation are applied.

The sand compaction pile used as the substitution method and the mixed treatment method used as the consolidation method are widely used because they can improve the strength of the soft ground through replacement or solidification of the surface or deep layers to increase the bearing capacity, but if the depth is deep. Due to the high replacement ratio, there was a disadvantage that economical efficiency and constructability were poor.

In addition, the foundation system includes a raft foundation, a pile foundation, and a piled raft foundation that combines them. The front foundation of the pile support is a method in which the raft distributes the load of the upper structure to secure support, and the pile suppresses excessive settlement of the raft and supports the structure through complementary roles to support the upper structure.

This is an economical method that is superior in bearing capacity and suppression of settlement compared to other pile-based methods. However, when applied to soft ground, it is due to the settlement problem due to the weight of the raft, the reduction of the support effect of the raft, and the problem of having to construct the pile to the support layer. Not effective

(Patent Document 1) KR10-1466563 B1

(Patent Document 2) KR10-1172519 B1

Patent Document 1 is to form a cement base layer, laminate a lightweight mixed soil on the cement base layer to form a lightweight base layer, form a cement solidified surface layer on the lightweight base layer, and laminate a lightweight mixed soil on the cement solidified surface layer. By forming a lightweight embankment layer, and by laminating the soil on the lightweight embankment layer, by forming a soft ground improvement embankment layer having a structure in which the lightweight layer and the cement layer are stacked alternately, the load on the soft ground is reduced and the It is an improvement method that can increase support capacity.

However, when the method for improving soft ground as in Patent Document 1 is used to improve and reinforce the soft ground of the seabed or dredged landfill as cement is mainly used as a stable treatment material, by changing the environment by the strong alkalinity of the cement, marine plants or There is a problem that it can cause a big problem in the ecosystem such as the growth and aquaculture of living things, and this can cause serious environmental problems.

Patent Document 2 excavates the soft ground according to the marking line on the soft ground surface and installs solidified soil to install a ground wall, install a solidified soil mat on the top of the installed underground wall, and a substitution layer on the constructed solidified soil mat. After installing crushed stone on the top of the installed substitution layer, a conical pile is installed according to the reinforced position, crushed stone is filled around the installed conical pile, and a finishing layer is installed on the top of the installed conical pile. It is an improvement method that can secure the bearing capacity for the overhead load of the design structure required in the ground, suppress lateral deformation, and secure environmental properties.

However, the method of improving the soft ground as in Patent Document 2 requires the construction of the underground wall, solidified soil mat, substitution layer, and conical piles in sequence, so the overall process is very complex and the construction period is long, increasing the overall construction cost. There is a concern that voids may be generated, which may cause a problem of lowering the strength of the ground.

Accordingly, the present invention is to solve the above-described problems, and its object is eco-friendly because it is possible to increase the ground strength by using a stone bag containing an aggregate that is easy to secure materials, and it is easy to improve construction on soft ground. To shorten the construction period and reduce the overall construction cost, it is intended to provide a method of improving soft ground using a stone bag.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. I will be able to.

As a specific means for achieving the above object, in the method of improving soft ground using a stoneback according to a preferred embodiment of the present invention, in the construction method of improving to reinforce the soft ground, flattening the surface of the original ground step ; Forming a first mat layer by laying at least one first mat on the original ground; Forming a stone back layer having a predetermined height by arranging and arranging a plurality of stone bags in which aggregates are contained in a net on the first mat; Filling material having a particle size relatively smaller than that of the aggregate is filled in the voids between the stone bags adjacent to each other and the voids between the aggregates contained in the stone bag, and a filling material is placed in the stone back layer to cover the plurality of stone bags as a whole. Laying and forming an improved layer; And forming a second mat layer by laying a second mat on the improved layer. It characterized in that it comprises a.

In this case, the step of forming the stoneback layer includes disposing a net inside the box body that is open to the top, and then forming a stone bag by filling an aggregate having a particle diameter of a certain size through the open entrance of the net. And carrying the stone bag lifted to be separated from the box body to the first mat layer after bundling the inlet as a bundling rope.

At this time, the inner surface of the box body is provided with an impact-absorbing rubber sheet in contact with the outside of the net.

In this case, a blocking sheet is provided inside the mesh to prevent the aggregate and the filler filling the voids generated between the aggregate from escaping to the outside of the mesh.

Preferably, it includes a stone bag arranged in alignment with the first mat layer, another stone bag adjacent thereto, and a support material that replaces a filling material and is located in a space formed between the first mat layer, and forms the first mat layer. In the step of arranging a support member at a predetermined interval on the first mat, and in the step of forming the stone back layer, the lower outer border of the stone bag arranged and arranged on the first mat and the inclined exterior of the support member The sides come into contact.

According to the preferred embodiment of the present invention as described above has the following effects.

An improvement in which a stone back layer consisting of a plurality of stone bags made of a mesh filled with aggregates is formed between the first and second mat layers, while the sound material is filled in the voids formed between the aggregates, covering the stone back layer as a filling material. By forming a layer, it is possible to significantly reduce the load on the soft ground, increase the support capacity of the soft ground, and reduce the spread of vibration or noise around the improved soft ground.

It is eco-friendly because it is possible to increase the strength and support of soft ground by using a stone bag containing aggregates such as crushed stone or gravel, which are easy to secure materials, and can shorten the construction period due to easy improvement of soft ground. Therefore, it is possible to reduce the overall construction cost.

1A to 1E are schematic process diagrams showing a method of improving soft ground using a stoneback according to an embodiment of the present invention.
2 is a process flow chart showing a method of improving soft ground using a stoneback according to an embodiment of the present invention.
3A and 3B are diagrams illustrating a process of forming a stone bag in a box body in a method for improving soft ground using a stone bag according to an embodiment of the present invention.
4 is an exploded perspective view showing a box body and a net for forming a stone bag in a method for improving soft ground using a stone bag according to an embodiment of the present invention.
5A and 5B are schematic diagrams showing a process of adding a support material in the method of improving soft ground using a stoneback according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in which a person of ordinary skill in the art can easily implement the present invention. However, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, the same reference numerals are used for parts having similar functions and functions throughout the drawings.

In addition, throughout the specification, when a part is said to be'connected' to another part, it is not only'directly connected', but also'indirectly connected' with another element in the middle. Include. In addition, "including" a certain component means that other components may be further included, rather than excluding other components unless specifically stated to the contrary.

In the method of improving soft ground using a stoneback according to a preferred embodiment of the present invention, as shown in FIGS. 1A to 2, the step of flattening in order to improve while reinforcing the soft ground (S1), forming a first mat layer And forming a stoneback layer (S3), forming an improved layer (S4), and forming a second mat layer (S5).

The flattening step (S1) is to flatten the upper surface while compacting the original ground, which is a soft ground, which is an improvement object, using equipment such as a compactor, as shown in FIG. 1A.

In the step of forming the first mat layer (S2), as shown in FIG. 1B, by placing at least one first mat 10 as a whole on the flattened base, a first mat for placing a stone bag to be described later. It is to form a layer.

The first mat 10 is a geosynthetic material provided as a PET woven mat in which polyester high-strength filament yarn is woven firmly at high density, or a PP woven mat in which polypropylene plain yarn is woven firmly at high density.

The first mat layer formed by the first mat 10 performs a separating function of separating the original ground, which is a soft ground, and the stoneback layer 20a, which will be described later, from each other, and performs a reinforcing function after completion of the improvement process.

Here, the first mat 10 is laid on the original ground to form a first mat layer separated from the original ground, thereby transferring and transporting the stone bag 20 to be described later to form the stone back layer 20a and filling material 30 When operating heavy equipment such as cranes or dump trucks in the process of transporting and transporting, it is possible to prevent damage to the surface of the original ground that has been flattened in the major and reduce the operating burden of heavy equipment.

In the step of forming the stone back layer (S3), a plurality of stone bags 20 in which a certain amount of aggregate 21 having a particle diameter of a certain size is contained in a net 22 are formed to form the first mat layer. The stoneback layer 20a having a predetermined height is formed on the first mat layer by sequentially arranging and placing them in contact with each other.

In the step of forming the stoneback layer (S3), as shown in FIGS. 3A, 3B, and 4, the mesh 22 is placed inside the box body 23 that is open to the top, and then the mesh is opened. The step of forming a stone bag 20 by filling the aggregate 21 having a particle diameter of a certain size through the inlet, and bundling the inlet of the net 22 as a bundling rope 26b, and then lifting it to be separated from the box body. And conveying the losing stone bag 20 to the first mat layer.

At this time, the inner surface of the box body 23 is provided with an impact absorbing rubber sheet 24 in contact with the outer side of the net 22, and thus is made of a metal plate when the aggregate is dropped through the open inlet of the net. It prevents cracking of the aggregate 21 due to a direct collision between the box body 23 and the aggregate 21, and minimizes noise generation due to the collision.

The aggregate 21 contained in the net may be provided with crushed stone or gravel having a relatively larger particle diameter than the particle diameter of the filler to be described later.

The rubber sheet 24 may be provided integrally or detachably on the inner surface of the box body.

In addition, the box body 23 may be formed of a hexahedral structure having the same size as the open inlet and the bottom surface, but is not limited thereto, and the size of the open inlet 23a is larger than that of the bottom surface. It is made of a structure that is formed wide and has an inner diameter spreading toward the top, and by providing a rubber sheet (24a) on its inner surface, the aggregate 21 lifts the stone bag 20 contained in the net 22 to the top The process of separating the box body 23a from each other can be performed more smoothly.

In addition, the box body 23 is provided with a scale part so that the filling height of the aggregate 21 supplied through the open inlet of the mesh 22 can be visually checked, so that the box body A plurality of stone bags 20 having the same volume and size are formed in the box body 23 under uniform conditions by always filling a certain amount of aggregate 21 in the net arranged inside the net, and then the first It can be arranged and arranged to form a stone back layer by transporting it to the mat layer.

The box body 23 is made of a substantially rectangular parallelepiped box structure with an open top and a closed bottom surface, and the net 22 is made of a fibrous net having a mesh size relatively smaller than the particle size of the aggregate to be filled.

This net 22 is provided with a bundling rope (26b) to bundle the opening after the filling of the aggregate (21) is completed, and the heavy stone bag (20) is lifted from the box body using heavy equipment such as a crane. It may be provided with a lifting rope (26a) to which the hook of the crane is hooked and connected so as to be transported to the next first mat layer.

Accordingly, the open entrance of the net 22 filled with the aggregate in the box body 23 is bound by the bundling rope 26b to form a stone bag 20, and a crane on the lifting rope 26a After hooking the hook of the box body 23, the stone bag 20 inside the box body 23 is lifted to separate the stone bag 20 from the box body 23, and the raised stone bag 20 is sequentially removed. The stoneback layer is formed by transporting it on a mat and arranging it.

In addition, it is preferable to provide a blocking sheet 25 in the inside of the net 22 to prevent the filling material 30 filled in the void generated between the aggregate and the aggregate from escaping to the outside of the net 22 Do.

The step of forming the improved layer (S4) is formed between the pores formed between the stone bags 20 adjacent to each other and the aggregates 21 contained in the stone bag 20, as shown in FIG. The filling material 30 having a particle diameter relatively smaller than that of the aggregate 21 is filled in the void, and at the same time, the stone back layer formed by the plurality of stone bags 20 arranged in alignment with the first mat layer is covered. By installing the filling material 30 on the stone back layer 20a, the improved layer 30a having a predetermined height in which the plurality of stone bags 20 are embedded is formed.

The filling material installed in the stoneback layer 20a is made of a size smaller than the particle size of the aggregate 21 filled in the mesh of the stoneback, and thus naturally flows into the gap or void between adjacent stonebags forming the stoneback layer. Is filled, and naturally flows into and fills the gap between the aggregates 21 filled in the mesh 22 of the stone bag 20, thereby fundamentally preventing the occurrence of gaps that are the cause of the settlement caused by vertical loads. Will be prevented.

In addition, a filling material is provided to cover the stoneback layer to form an improved layer, and then a compaction process is performed in which an impact is applied to the upper surface of the improved layer by a compactor in a vertical direction.

Through this compaction process, the filling material flows into the voids between adjacent stone bags or the voids between the aggregates, thereby increasing the filling efficiency and flattening the surface of the improved layer.

Finally, in the step of forming the second mat layer (S5), as shown in FIG. 1E, by laying and covering the second mat 40 as a whole on the improved layer 30a, rainwater is transferred to the improved layer in case of rain. To form a second mat layer that prevents flooding.

Like the first mat, the second mat may be provided as a PET woven mat in which polyester high-strength filament yarn is woven firmly at a high density, or a PP woven mat in which polypropylene plain yarn is woven firmly at high density, but is limited thereto. It is not possible to be provided with a waterproof vinyl material.

On the other hand, the stone bag 20 arranged in the first mat layer, the other stone bag 20 adjacent thereto, and a support material 50 that is located in the space formed between the first mat layer and replaces the filling material 30 ).

That is, the support member 50 is disposed on the first mat 10 at a predetermined interval as shown in FIG. 5A in the step of forming the first mat layer, and then forms the stone back layer. In the step, the lower outer edge of the stone bag 20 and the inclined outer surface 52 that is placed on the first mat 10 and arranged in alignment are in contact with each other.

This support member 50 may be made of a square pyramid having four inclined outer surfaces 52 extending from the vertex 51, and the inclined outer surface 52 is preferably made of a concave curved surface, the Each inclined outer surface 51 of the support member 50 is preferably in contact with the lower outer edges of the four stone bags at the same time.

The support member 50 may be fixedly installed on the first mat 10 by a separate fixing member such as a vertical pin so as to be fixed in position without moving on the surface of the first mat 10.

Accordingly, as the stone bags filled with aggregates are placed on the first mat and arranged in alignment, the stone bags 20 adjacent to each other come in contact with one support member 50. ) Is to fill the empty space replacing the filling material 30 by the support member 50 located in the space formed between the first mat (10).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those who have the knowledge of.

10: first mat
20: Stone Bag
21: aggregate
22: net
23: box body
24: rubber sheet
25: rubber sheet
20a: Stoneback layer
30: aggregate
30a: improved layer
40: second mat
50: base material

Claims (5)

In the construction method of improving to reinforce the soft ground,
Flattening while compacting the surface of the original ground;
Forming a first mat layer by laying at least one first mat on the original ground;
Forming a stone back layer having a predetermined height by arranging and arranging a plurality of stone bags in which aggregates are contained in a net on the first mat;
Filling material having a particle size relatively smaller than that of the aggregate is filled in the voids between adjacent stone bags and the aggregates contained in the stone bag, and a filling material is placed in the stone back layer to cover the plurality of stone bags as a whole. Laying and forming an improved layer;
Forming a second mat layer by laying a second mat on the improved layer; Soft ground improvement construction method using a stone back, characterized in that it comprises a. The method of claim 1,
The forming of the stoneback layer includes disposing a net inside the box body that is open to the top, and then forming a stone bag by filling an aggregate having a particle diameter of a predetermined size through the open entrance of the net, and A method of improving soft ground using a stone bag, comprising the step of carrying a stone bag lifted to be separated from the box body after being bundled as a bundled rope to the first mat layer. The method of claim 2,
A method of improving soft ground using a stone bag, characterized in that the inner surface of the box body is provided with a rubber sheet for absorbing impacts in contact with the outside of the net. The method of claim 1,
A method of improving soft ground using a stoneback, characterized in that the mesh is provided with a blocking sheet in the inside of the mesh to prevent the aggregate and the filler filling in the voids generated between the aggregate from escaping out of the mesh. The method of claim 1,
A stone bag arranged in alignment with the first mat layer, another stone bag adjacent thereto, and a support material positioned in a space formed between the first mat layer to replace the filling material,
In the step of forming the first mat layer, a base material is disposed on the first mat at regular intervals, and in the step of forming the stone back layer, the lower outer edge of the stone bag is placed on the first mat and arranged in alignment. And the soft ground improvement construction method using a stoneback, characterized in that the inclined outer surface of the base material is in contact.

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