KR101523948B1 - Construction method of underground structure under the established building - Google Patents

Abstract

The present invention relates to a method to build an underground structure (100) under an existing structure, such as a bridge, while safely maintaining and using the existing structure. The method to build an underground structure under an existing structure comprises: i) a step of building working stations (310) on both sides of a working area (320) where an underground structure (100) is installed; ii) a step of building an extended foundation part (110) by performing upper grouting right under a foundation (210) positioned in the working area (320); iii) a step of reinforcing a steel pipe installation part (120) by performing lower grouting right under the extended foundation part (110); iv) a step of forming a steel pipe loop (130) by successively press-fitting steel pipes (130a) for a loop in the steel pipe installation part (120); and v) a step of installing the underground structure (100).

Description

[0001] The present invention relates to a method of constructing an underground structure under an existing structure,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method of an underground structure, and more particularly, to a construction method of constructing an underground structure at a lower portion of the bridge while safely maintaining the use of existing structures such as bridges.

In the latter half of the 1960s, many bridges such as overpasses were built due to the construction of an efficient road traffic system in the city. However, due to their aging, structural safety became insufficient, maintenance costs became excessive, In recent years, there have been increasing cases of eliminating traffic problems caused by the removal of such overpasses, road maintenance, improvement of traffic signal system, and the like.

On the other hand, in the case of removing the overpass that traverses the railway, there is a limit to solving the problems due to the removal of the overpass through the improvement of the traffic signal system. Therefore, it is necessary to install a transverse underground structure corresponding thereto, It is necessary not only to ensure structural stability in the upper railway, but also to remove the overpasses that can be safely used until the construction of underground structures is completed.

Particularly, a support pile is usually installed at the lower part of the bridge pier of a bridge for an overpass, and a new underground structure must pass through the support pile, so that conventional underground structure building methods can not be applied.

In the case where the support pile is installed at the bottom of the existing structure, a method of constructing the underground structure while securing the safety of the existing structure has been proposed in Patent Registration No. 10-1011805.

The prior art described above relates to a method of constructing a structure for constructing a structure at the lower part of a pile bridge or an underground roadway such as a pile, and is to propel a steel pipe constituting a sidewall on both sides of the space in which the underground structure in the ground, Thereby forming a steel pipe loop for earthworks, digging the inside thereof, and installing a strut and a pillar between the both side walls to achieve structural stability of the existing structure.

However, in the above-mentioned prior art, when the steel pipe is inserted into the ground for the composition of the steel pipe loop, there is a fear that the soil on the upper part of the steel pipe is relaxed due to friction with the steel pipe, In order to install temporary support pillars and temporary columns, the inside of the steel pipe loop is excavated in advance, which may cause another immovable settlement.

Accordingly, the present applicant has proposed a method of constructing an underground structure capable of achieving structural stability of a bridge by broadening the existing load by enlarging the existing foundation so as to prevent floating settlement of the existing structure, for example, 1388521.

The method of constructing the underground structure of the above-mentioned patent No. 1388521 shows the advantage that the underground structure can be constructed safely while maintaining the structural stability of the bridge even after removing the support pile through the expansion of the foundation, There is a problem that an additional process such as the installation of the vans is required.

KR 10-1011805 B1 KR 10-1388521 B1

It is an object of the present invention to provide a method for constructing a new underground structure while maintaining the safety of an existing structure without installing a temporary structure such as a temporary hood or the like .

It is another object of the present invention to provide a method of constructing an underground structure capable of preventing the loosening of soil caused by the insertion of a roof steel pipe into the ground during the process of constructing an underground structure.

According to a preferred embodiment of the present invention for solving the above-mentioned problems, there is provided a method of manufacturing a work station, comprising the steps of: i) constructing a work station on both sides of a work section in which an underground structure is installed; Ii) constructing an enlarged base portion by performing an upper grouting right under the foundation located within the work section; Iii) reinforcing the steel pipe mounting portion by performing lower grouting right under the enlarged base portion; Iv) forming a steel pipe loop by press fitting the steel pipe for the loop into the steel pipe installation part in sequence; And (v) installing an underground structure. In the upper grouting in the step (ii), a plurality of high-strength pipes are inserted into the ground, and the grout material is injected through the high-strength pipes. An underground structure construction method under the structure is provided.

According to another embodiment of the present invention, the lower grouting in the step iii) is performed by inserting a plurality of low-strength pipes into the ground and injecting the grout material through the grouting, thereby reinforcing the steel pipe installation part. A construction method is provided.

According to another embodiment of the present invention, a method of constructing an underground structure under a conventional structure is provided in which a to-wall is provided on the front and rear surfaces of a work section, and each end of the high-strength pipe inserted in the ground is fixed to the to- do.

According to another embodiment of the present invention, the high-strength pipe insertion in the upper grouting in the step ii) is performed by installing a drill bit at the tip of the high-strength pipe and simultaneously performing the drilling operation; The insertion of the low-strength pipe in the lower grouting in the step iii) is inserted after the punching operation for forming the punch hole with the puncher is completed, wherein a method of constructing the underground structure under the existing structure is provided.

According to another embodiment of the present invention, the grout reinjection in the upper grouting in the step (ii) is performed without injecting a sealing material between the inner surface of the perforation hole into which the high-strength pipe is inserted and the outer surface of the high- ; The grout reinjection in the lower grouting in the step (iii) is carried out with a sealing material injected between the inner surface of the perforation hole into which the low-strength pipe is inserted and the outer surface of the low-strength pipe. A construction method is provided.

According to another embodiment of the present invention, there is provided a method of constructing an underground structure under a conventional structure, wherein press-fitting of a steel pipe for a steel pipe to a steel pipe installation portion proceeds while eliminating an interfering low-strength pipe.

The present invention excludes the use of a temporary member such as a hypothetical vent and the installation work thereof, so that it can reduce the material and the construction cost, and can achieve an economical effect of shortening the air.

In addition, since the concentrated load due to the foundation is dispersed throughout the work area, there is little room for floating settlement of the existing structure, so that the effect of the structure safety that can secure the safe use of the existing structure is demonstrated.

In addition, according to the present invention, since the slip soil of the steel pipe installation portion into which the steel pipe for the loop is inserted is blocked by grouting, the relaxation phenomenon of the slurry is significantly reduced, thereby achieving another structural safety effect of preventing settlement of the upper slurry.

FIG. 1 is a sectional view of a work station constructed on both sides of a work section in which an underground structure will be installed in the present invention.
Fig. 2 is a sectional view showing the entire construction of the present invention, in which (a) is a cross-sectional view, (b) is a longitudinal sectional view, and Fig.
FIG. 3 is a perspective view showing a state where the pipe is inserted, FIG. 4 is a state in which the injection port of the perforation hole is caulked, FIG. 6 is a cross-sectional view showing a state in which surrounding soil is grouted by injecting a grout material.
7 is a perspective view showing a state in which the upper grouting of the present invention is completed to form an expanded base portion.
8 is an explanatory view showing a process of lower grouting according to the present invention.
Fig. 9 is a perspective view showing a state where a steel pipe for a loop is inserted into a steel pipe installation part of the present invention. Fig.
FIGS. 10 and 11 are cross-sectional views showing respective forms of an underground structure finally constructed by applying an underground structure construction method of the present invention to a lower portion of an existing structure such as a bridge and an apartment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in order to obscure or obscure the technical idea of the present invention due to the detailed description of the known structure in describing the present invention, the description of the structure of the above known structure will be omitted.

1 is a schematic view showing a construction of a work station 320 on both sides of a work section 320 where an underground structure 100 is to be installed in order to construct an underground structure 100 in the lower part of the existing structure 200, FIG. 2 is a perspective view showing the construction of the underground structure according to the present invention. FIG. 2 is a view showing the entire structure according to the present invention in order to explain important technical features of the underground structure construction method of the present invention. (B) is a longitudinal sectional view of the work section, and (c) is a plan view of the work section.

As shown in FIG. 2, the technical features of the construction method of an underground structure according to the present invention can be largely explained as follows.

First, in the construction method of an underground structure according to the present invention, an enlarged base portion is constructed by mass-forming a toe layer of the entire width of a work section immediately below the foundation, and an upper portion load transmitted by the foundation is mass- By minimizing the stress generated in the ground by dispersing the entire area of the work area, the structural stability of the existing structure is maintained.

Second, the method of constructing an underground structure according to the present invention is characterized in that the roof steel pipe is easily press-fitted into the steel pipe installation portion located immediately below the enlarged foundation portion, while the steel pipe is not press- The steel pipe installation portion is reinforced to prevent settlement of the upper soil gravel.

These technical features are accomplished by two grouting, which are located at the upper and lower parts of each other with respect to the soil layer at the bottom of the foundation 210, and whose materials and methods are different from each other.

The enlarged base 110, which is the mass of the soil layer, is constructed by an upper grouting which is carried out with respect to the entire width of the work section 320 at a position directly beneath the foundation 210.

3 to 6 are cross-sectional views illustrating the steps of the upper grouting process, in which a) a step of installing a high strength pipe 111 provided with a perforation and grout reinforcement hole p, b) C) inserting the packer 113 for reinjecting the grout into the high strength pipe 111, d) inserting the grouting pump 111 into the high strength pipe 111, The grout material is injected into the high strength pipe 111 and the perforation hole H to grout the soil material around the perforation hole H. [

On the other hand, since the upper grouting is performed directly below the foundation 210, the perforation hole H by the independent piercing operation can easily collapse and cause a settlement phenomenon on the bottom surface of the foundation 210.

Accordingly, in the present invention, the operation of inserting the high strength pipe 111, which is the grout pipe, for the upper grouting is performed by drilling a hole in the ground by installing a drill bit (not shown) at the tip of the inserted high strength pipe 111 It is preferable to proceed to a direct hole drilling method in which the simultaneous high strength pipe 111 is inserted into the hole H.

In the case where the support pile 220 is provided on the bottom surface of the foundation 210, the ground penetration of the high strength pipe 111 is made between the angles of the support piles 220, The structural stability of the support pile 220 should be maintained.

Herein, the term "high-strength pipe" refers to a small-diameter pipe generally referred to as a pipe having a strength not lower than the strength of a steel pipe of at least a metal material. The pipe is made of carbon fiber reinforced plastic, glass fiber reinforced plastic, aramid fiber reinforced plastic ≪ / RTI >

On both sides of the work section 320, a work is performed to construct the work station 310. To the front and rear sides of the work section 320, .

Therefore, according to another embodiment of the present invention, each end of the high strength pipe 111 installed in the ground is fixed to the toothed wall W so that the structural integrity of the enlarged base 110 can be secured to a greater extent.

When the high strength pipe 111 is to be fastened to the respective toothed walls W of the two working bases 310 as described above, before the packer 113 is inserted into the high strength pipe 111, It is a matter of course that the caulking 112 is also applied to the penetrating portion of the opposite end of the perforation hole so that the perforation hole H is sealed.

When the insertion of the high strength pipe 111 is completed and the caulking 112 for the injection port A of the perforation hole H is completed and the perforation hole H is closed, the packer 113 is inserted into the high- And the selected grout material 114 is injected into the perforation hole H by using an automatic pressure regulating device.

It is preferable that the grout material 114 exhibits a high cementing speed and exhibits high strength after cementation, and cement milk, water glass, or chemical grout material may be used alone or alternatively, The permeability of the groundwater is selected according to conditions such as the flow of groundwater.

As shown in FIG. 7, when grouting is completed in a state where a plurality of high-strength pipes 111 are inserted by each of the above-described steps, a reinforcing concrete structure such as a reinforced concrete structure in which a high- An enlarged base 110 is constructed to distribute the concentrated load delivered from the base 210 over the entire work area 320.

When the construction of the enlarged foundation 110 is completed by the upper grouting, the soil layer located immediately below the enlarged foundation 110 is reinforced with respect to the steel pipe installation part 120 through the lower grouting.

Here, the steel pipe installation part 120 refers to a steel pipe installation part 120 that is used to separate a part to be rolled or removed for installation of an underground structure 100 to a to-earth layer, or to utilize it as a structural reinforcement or an upper slab of an underground structure 100 This is the part that continuously inserts the steel pipe in the loop in the ground.

If the loop steel pipe 130a is pressed to form the steel pipe loop 130 in the ground, the soil around the steel pipe can be relaxed by the frictional force of the outer surface of the steel pipe to affect the stability of the upper structure. , The steel pipe is propelled and the grout material is sprayed to the rear to prevent the above-mentioned loosening of the soil.

However, the above-mentioned method can not completely prevent the loosening of the soil because there is a time gap between the loosening point of the loam and the spraying and consolidation time of the grout material.

Therefore, in the present invention, grouting reinforcement is applied to the steel pipe installation part 120 so that the above-mentioned gravel is not loosened substantially, and the watertightness of the steel pipe loop 130 is ensured, Let it increase together.

Meanwhile, as described above, the steel pipe 130a for the loop should be easily inserted into the steel pipe installation part 120. The lower grouting for the steel pipe 130a is different from the upper grouting for constructing the enlarged foundation 110, The method is different.

 8 illustrates one embodiment of the lower grouting for reinforcement of the steel pipe installation part 120 in each step.

The lower grouting is performed by using a low strength pipe 121 as a grout pipe which does not use a high strength pipe 111 but which is easy to remove and that a low strength pipe 121 is formed by forming a perforation hole H by perforating, And the sealing material 125 is injected into the perforation hole H, which is different from the above-described upper grouting.

Therefore, the term "low-strength pipe" refers to a structure that is resistant to the injection pressure of the grout material and is made of a material that is easily broken or cut, as compared with a "high-strength pipe." For example, It should be considered as a collective pipe.

The lower grouting includes the steps of: a) forming a perforation hole H by perforating the steel pipe installation part 120; b) forming a grout reinforcement hole p in the perforation hole H, Inserting the pipe 121 into the hole H; c) sealing the hole H with the caulking 122 to the hole A of the hole H; d) 125); e) inserting a packer (123) for re-grouting into the low-strength pipe (121); and f) forming a grout material (124) in the perforation hole (H) by using a grouting pump And grouting the gravel around the perforation hole (H).

Since the enlarged base portion 110 is located between the base 210 and the base 210 to which the concentrated load is applied, the steel pipe installation portion 120 to be subjected to the lower grouting can be maintained as it is. Therefore, it is not necessary to simultaneously insert the perforation and the grout pipe as in the upper grouting step.

In addition, the looped steel pipe 130a is press-fitted into the steel pipe installation part 120. At this time, a portion interfered by the grout pipe installed in the steel pipe installation part 120 may occur, This facilitates the removal of the tube tube at the interference portion, thereby facilitating the insertion operation of the steel tube 130a for the loop.

Therefore, in the lower grouting step of the present invention, after the perforation hole H is formed, the low strength pipe 121 is inserted into the perforation hole H to have the above-mentioned effect.

When the insertion of the low-strength pipe 121 is completed and the caulking 122 for the injection port A of the perforation hole H is completed and the perforation hole H is sealed, a packer 123 The sealing material 125 is filled in the perforation hole H so that no space is formed between the porous wall of the perforation hole H and the low-strength pipe 121.

The sealing material 125 should be able to grout the surrounding soil by penetrating and spreading the grout material 124 injected through the grout material injection hole p provided in the low-strength pipe 121, The crown strength should not be too high to facilitate the push-in propulsion of the steel pipe (130a).

When the filling operation of the sealing material 125 is completed, the packing 123 is inserted into the low-strength pipe 121, and the grout material is injected into the hole H to reinforce the steel pipe fitting part 120 Complete.

When the upper grouting and the lower grouting with respect to the lower part of the foundation 210 of the existing structure 200 are completed, the steel pipe 130a is sequentially inserted into the reinforced steel pipe installation part 120 to form the steel pipe loop 130 .

9 is a perspective view showing a state in which the steel pipe 130a is inserted into the steel pipe installation part 120. FIG.

As shown in FIG. 9, when the low strength pipe 121 interfered with during the process is removed and the support pile 220 for supporting the foundation 210 is installed And then proceeds while cutting the support pile 220.

When the formation of the steel pipe loop 130 is completed by continuously inserting the steel pipe 130a for the loop into the ground, the underground structure 100 is built inside the steel pipe loop 130.

FIG. 10 is a cross-sectional view of various bases of the existing bridges and elevated roads, and FIG. 11 is a cross-sectional view of various embodiments in which an underground structure 100 is constructed for a lower portion of an existing apartment through the above-described steps. As described above, the underground structure construction method of the present invention can be applied universally regardless of the use or form of the existing structure, and whether or not the support pile is present.

The construction of the underground structure 100 may be implemented by an enclosing method of towing or propelling a hull which has been manufactured in advance on the work station 310. The excavation of the inner soil of the steel pipe loop 130, And concrete can be put in place after the form is installed.

As shown in Fig. 10 or 11 (a), the underground structure 100 may be built inside the steel pipe loop 130 while keeping the steel pipe loop 130 intact, it is possible to construct the underground structure 100 by removing a part of the steel pipe while using the steel pipe loop 130 as the upper slab of the underground structure 100, And may be arbitrarily selected or modified according to the site conditions.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the invention is not limited to the disclosed embodiments, but, on the contrary, It is obvious that it will be possible to carry out various modifications thereof. It is therefore intended that such modifications are within the scope of the invention as set forth in the claims.

100; An underground structure 110; Expansion base
111; High strength pipes 112, 122; Caulking
113, 123; Packers 114, 124; Grout
120; A steel pipe installation part 121; Low-strength pipe
125; Sealing material 130; Steel pipe loop
130a; A steel pipe 200 for a loop; Existing structure
210; Foundation 220; Support pile
310: work station 320: work section
W; Earth wall H; Perforated hole
A; Inlet p; Grout re-injection hole

Claims (6)

A method of constructing an underground structure (100) in a lower part of an existing structure (200) in a state where the existing structure (200) is maintained, comprising the steps of: i) constructing a work station (310) on both sides of a work section (320) ; Ii) constructing an enlarged foundation 110 by performing an upper grouting right under the foundation 210 located in the work section 320; Iii) reinforcing the steel pipe installation part (120) by performing lower grouting right under the enlarged base part (110); Iv) forming a steel pipe loop 130 by sequentially pressing the steel pipe 130a into the steel pipe installation part 120; V) installing an underground structure 100,
The upper grouting in the step ii) is performed by inserting a plurality of high strength pipes 111 into the ground and injecting the grout material 114 therethrough so that the integrated enlarged foundation 110 is constructed. Construction Method of Underground Structures. The method according to claim 1, wherein the lower grouting in step (iii) is characterized in that the steel pipe installation part (120) is reinforced by inserting a plurality of low strength pipes (121) into the ground and injecting the grout material Construction method of underground structures under existing structures. 2. The structure as claimed in claim 1, wherein a workpiece W is provided on the front and rear surfaces of the work section 320, and each end of the high-strength pipe 111 inserted into the ground is fixed to the to- Construction method of underground structures in the lower part. 3. The method according to claim 2, wherein the step of inserting the high strength pipe (111) in the upper grouting of step (ii) comprises the step of installing a drill bit at the tip of the high strength pipe (111) The insertion of the low-strength pipe 121 in the lower grouting in the step iii) is inserted after the punching operation for forming the hole H with the punching machine is completed. The method according to claim 2, wherein the grout reinjection in the upper grouting in the step (ii) is performed by inserting a seal material (125) between the inner surface of the perforation hole (H) into which the high- ) Is not injected; The grout reinjection in the lower grouting in the step iii) is performed by injecting the seal material 125 between the inner surface of the perforation hole H into which the low strength pipe 121 is inserted and the outer surface of the low strength pipe 121 A method of constructing an underground structure under an existing structure. The method according to claim 2, wherein press-fitting of the steel pipe (130a) for the steel pipe installation part (120) proceeds while removing the low-strength pipe (121) interfering with the steel pipe installation part (120).

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