KR101854660B1 - Closed tunnel filler part reinforcement structure using large diameter steel pipe and construction method thereof - Google Patents

Abstract

The present invention relates to a method of constructing a filler part reinforcement structure using a large diameter steel pipe in close tunnels in which a northbound tunnel and a southbound tunnel are constructed close to each other, the method characterized by including the steps of: inserting large diameter steel pipes into the filler portion in the longitudinal direction of a tunnel; while excavating a leading tunnel, placing a primary shotcrete, installing a steel rib, installing reinforcement materials for reinforcing the filler portion in the direction of a trailing tunnel, and placing a secondary shotcrete; and while excavating the trailing tunnel, placing a primary shotcrete, installing a steel rib, fixing exposed portions of the reinforcement materials, and placing a secondary shotcrete, wherein the reinforcement materials are installed to pass through the large diameter steel pipes, that have been inserted and installed in the filler portion, in the transverse direction thereof. According to the present invention, by inserting large diameter steel pipes passing through the inside of a filler portion, and installing reinforcement materials throughout a leading tunnel, a trailing tunnel, and large-diameter steel pipes to achieve an integrated construction, the construction can be simplified and the structural stability can be increased. In addition, by inserting and press-fitting the large diameter steel pipes through the reaction force of ground anchors after installing the ground anchors, insertion of large diameter steel pipes are facilitated and simplified and consequently economical construction can be carried out. In addition, by excavating the leading tunnel and the trailing tunnel after sufficiently securing the stability of the filler portion by inserting large diameter steel pipes in the filler portion for reinforcement, an effect of more stably constructing close tunnels may be provided.

Description

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a structure for reinforcing a close tunnel filler portion using a large diameter steel pipe,

The present invention relates to a structure for reinforcing a close tunnel pillar portion using a large diameter steel pipe and a method of constructing the same. More particularly, the present invention relates to a structure for reinforcing a pillar portion in a close tunnel where an uphill tunnel and a downhill tunnel are installed close to each other, The present invention relates to a structure for reinforcing a nearby tunnel pillar portion using a large diameter steel pipe and a construction method thereof.

Generally, when constructing close-up tunnels in which an uphill tunnel and a downhill tunnel are close to each other, a sufficient clearance between the uphill tunnel and the downhill tunnel is secured for the structural stability of the tunnel. In such a construction method, the spacing distance between the tunnels to ensure the structural stability of the tunnel, that is, the width of the pillar portion is formed to be 1.5 times or more the tunnel excavation width. It is difficult to form the width of the portion at least 1.5 times the tunnel excavation width.

In the case where it is difficult to form the pillar width wide, it is disclosed a construction method in which a central tunnel is formed at the center of both tunnels, a wall or a column is formed in the central tunnel, and the tunnel is extended to both sides thereof. However, such a construction method is complicated due to the construction of the center wall first and the construction of the preceding tunnel and the rear tunnel, and the construction period and the construction cost are increased, the load is concentrated on the central wall and the column, There is a problem that water leaks from the central wall or the upper part of the column.

In order to solve the above problems, Korean Patent No. 10-1677017 discloses a method of constructing a close-coupled tunnel using a hollow tube (see Figs. 11A to 11B). This prior art is a method of constructing a near parallel tunnel comprising a leading tunnel 110 and a trailing tunnel 120. The tunneling surface 201 has a plurality of intubation locations 130 at the outer periphery of a tunnel entrance or exit, ; A direct puncturing step of inserting the hollow tube 150 into the intubation groove while drilling the intubation groove 140 in parallel with the formation direction of the tunnel at each of the intubation locations displayed in the display step; An injection step of injecting the grout 160 into the hollow tube inserted in the direct drilling step; A curing step of curing the grout injected into the periphery of the hollow tube and the hollow tube in the injecting step; And an excavating step of excavating an inlet or an outlet of the tunnel when the grout is cured, wherein the injecting step includes the steps of: injecting the grout into the hollow pipe, Wherein the hollow tube is provided with an air discharge pipe for discharging the inside air of the hollow tube to the outside, a rear end of the hollow tube located inside the introducing duct is shielded by a packing material, The present invention relates to a method for constructing an adjacent parallel tunnel using a hollow tube for injecting the grout in a state in which the grout is installed, And the strength of the pillar portion formed between the preceding tunnel and the trailing tunnel is increased while the construction of the adjacent parallel tunnel is made easier The construction time can be shortened and the interval of the parallel tunnels can be minimized to facilitate the utilization of the space and to prevent the degradation of the natural environment as much as possible and to secure the safety while minimizing the interval of the near parallel tunnel The present invention provides a method of constructing a parallel tunnel using a hollow tube.

However, in the prior art, when the ground of the pillar portion is weak or the width of the pillar portion is narrow, there is a problem that the stability of the pillar portion is difficult to be secured by a plurality of small-diameter hollow tubes 150 and the grout 160.

In addition, the conventional art has a problem that it requires too much effort and time in the process of inserting a plurality of small hollow tubes 150.

In the prior art, a plurality of small-diameter hollow tubes 150 are coupled to each other by a chelate 160 that is not bonded to each other, but the stability is not ensured when the pillars are weak or the width is narrow.

Patent 1: Korean Patent No. 10-1677017

In order to solve the above-mentioned problems, the present invention is simple in construction by stacking longitudinally large-diameter steel pipes longitudinally in the pillars and bonding them together, and stiffening through large-diameter steel pipes between the preceding tunnel and the rear tunnel The structure stability is increased and the large diameter steel pipes are inserted by inserting the large diameter steel pipes through the reaction force of the ground anchor after installing the ground anchors. Thus, the large diameter steel pipes can be easily propelled and the construction is simple and economical. And a method of constructing a close tunnel filler portion reinforcing structure using a large diameter steel pipe that can stably construct a close tunnel by excavating a preceding tunnel and a succeeding tunnel after inserting a sufficient amount of the filler portion to secure stability of the pillar portion.

A method of constructing a reinforced structure of a close tunnel pillar using a large diameter steel pipe according to an example of the present invention is a method of constructing a reinforced structure of a pillar of a nearby tunnel in which an up tunnel and a down tunnel are installed close to each other, Inserting large diameter steel tubes in a longitudinal direction; Installing reinforcing materials for reinforcing the pillar portion in the direction of the trailing tunnel and installing a secondary shotcrete while pouring the primary shotcrete while excavating the preceding tunnel; A step of installing a first shotcrete while excavating the trailing tunnel, installing a steel support, fixing an exposed part of the reinforcement, and installing a second shotcrete, wherein the reinforcing materials are inserted into the large diameter And is installed so as to penetrate the steel pipes in the lateral direction.

Also, the step of inserting the large diameter steel tubes may include disposing the ground anchors around the point where the large diameter steel tubes are inserted, and inserting the large diameter steel tubes while pressing the large diameter steel tubes using the reaction force of the ground anchors.

Also, the step of inserting the large-diameter steel pipes may be characterized by inserting the inside of the large-diameter steel pipes while breaking the inside of the large-diameter steel pipes.

The method may further include the step of filling the interior of the large diameter steel tubes with concrete or soil cement after the step of inserting the large diameter steel tubes.

Also, the large-diameter steel pipes inserted into the pillar portion may be connected to each other by a connecting member provided on the side surface thereof.

Also, the large-diameter steel pipes are formed with through-holes passing through in the lateral direction at regular intervals along the longitudinal direction, the through-holes being closed by plates provided inside the large-diameter steel pipes, So that the through hole can be opened.

Further, the provision of the reinforcements may include forming holes extending through the large-diameter steel pipes from the preceding tunnel to the trailing tunnel, and inserting reinforcing bars into the holes, and then performing grouting.

Further, in a pillar portion reinforcing structure of a close tunnel using a large-diameter steel pipe according to an example of the present invention, in a pillar portion reinforcing structure of a nearby tunnel in which an up tunnel and a down tunnel are installed close to each other, Large-diameter steel pipes inserted and installed; And reinforcing members that are inserted through the large diameter steel pipes and joined to the side walls of the preceding tunnel and the rearward tunnel, and the large diameter steel pipes are connected to each other by a connecting member in the up and down direction.

Further, the large-diameter steel pipes may be arranged in one row in the vertical direction below the pillars, and two rows in the upper side so as to be installed in a Y-shape as a whole.

Also, the large-diameter steel pipes are installed in two rows in the vertical direction in the pillar portion, and each row of the large-diameter steel pipes is installed in contact with the preceding tunnel and the trailing tunnel.

Also, the large-diameter steel pipes are installed in three or more rows in the vertical direction in the pillar portion, and the respective columns at both ends of the large-diameter steel pipes are installed in contact with the preceding tunnel and the trailing tunnel.

Also, the large-diameter steel pipes are formed with through-holes passing through in the lateral direction at regular intervals along the longitudinal direction, the through-holes being closed by plates provided inside the large-diameter steel pipes, So that the through hole can be opened.

Further, the reinforcing materials may be installed through the through holes of the large diameter steel pipes inserted in the pillar portion in the lateral direction.

The present invention enables the construction to be simplified and the structural stability to be increased while the longitudinally-oriented large-diameter steel pipes are stacked vertically on the pillar portion and bonded together and the reinforcing members are inserted through the large diameter steel pipes between the preceding tunnel and the rear tunnel, By inserting the large diameter steel pipes through the reaction force of the ground anchor after installing the ground anchor, the large diameter steel pipe can be easily propelled and the construction is simple and economical. In addition, the large diameter steel pipe is inserted into the filler portion, It is possible to provide an effect that a nearby tunnel can be stably installed by excavating the preceding tunnel and the trailing tunnel.

1A to 1D are a sectional view and a plan view of a close tunnel filler portion reinforcing structure using a large diameter steel pipe according to an example of the present invention.
FIGS. 2 to 10 are views showing steps of a method of constructing a close tunnel filler portion reinforcing structure using a large diameter steel pipe according to an embodiment of the present invention.
6B to 6D are a cutaway view and a perspective view showing in detail a large-diameter steel pipe according to an example of the present invention.
11 is a drawing of the prior art.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to refer to like elements throughout the drawings, even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, May be "connected "," coupled "or" connected ".

Hereinafter, a reinforcing structure for a close tunnel filler portion using a large diameter steel pipe according to an embodiment of the present invention and a construction method thereof will be described in detail with reference to FIGS. 1 to 10. FIG.

1 to 10, a method of constructing a close tunnel filler portion reinforcing structure using a large-diameter steel pipe according to an embodiment of the present invention is a method of constructing a filler portion reinforcing structure of a nearby tunnel in which an up tunnel and a down tunnel are installed close to each other The first tunnel 40 is pierced while the preceding tunnel 10 is being excavated and the steel support is installed and the rear tunnel 20 is pierced by installing the first shotcrete 40. [ A step of installing reinforcing materials 50 reinforcing the pillar portion in the direction of the pavement and pouring the secondary shotcrete 42 while installing the primary shotcrete 40 while excavating the trailing tunnel 20, Fixing the exposed portions of the reinforcing members 50, and pouring the second shotcrete 42.

The step of inserting the large diameter steel pipes 30 is a step of inserting the large diameter steel pipes 30 in the longitudinal direction of the tunnel, that is, the traveling direction of the tunnel, to the pillar portion between the leading tunnel 10 and the trailing tunnel 20.

The large-diameter steel pipe 30 may be a large-diameter steel pipe 30 having a diameter of approximately 800 to 1500 mm and a large diameter.

When the width of the pillar portion is narrow, the large-diameter steel pipes 30 having a large diameter may be stacked on top of each other while filling up the pillar portions. On the upper side, they can be separated from each other while contacting the preceding tunnel 10 and the succeeding tunnel 20, and can be installed in a generally Y-shape. The large-diameter steel pipe 30 thus inserted has a sufficient rigidity so that the collapse or breakage of the pillar portion can be prevented, and the structural stability of the pillar portion can be secured.

Further, when the width of the filler portion exceeds approximately twice the diameter of the large diameter steel pipe 30, the large diameter steel pipe 30 can be stacked in two. That is, the large-diameter steel pipe 30 of two rows can be stacked while being tied upwards while contacting the up tunnel and the down tunnel, so that the filler portion between the leading tunnel 10 and the trailing tunnel 20 can be stacked with the large- The structural stability can be secured.

Further, when the width of the pillar portion exceeds 3 times the width of the large diameter steel pipe 30, the large diameter steel pipe 30 can be laminated in three rows. That is, the large-diameter steel pipes 30 of two rows are stacked on top of each other while being tangent to the preceding tunnel 10 and the trailing tunnel 20, and the remaining one column is stacked upwards from the middle of the two columns .

In the step of inserting the large diameter steel pipe 30, the ground anchors are first installed on the periphery of the point where the large diameter steel pipes 30 are inserted, for example, on both sides of the large diameter steel pipe 30, The steel pipe 30 can be inserted while being press-fitted. Therefore, the large-diameter steel pipe 30 can be easily and promptly and economically constructed.

The insertion of the large-diameter steel pipes 30 can be carried out while inserting the inner pipe. That is, the large-diameter steel pipes 30 can be easily inserted by pressing the large-diameter steel pipes 30 in the front of the large-diameter steel pipe 30 to be fastened by various methods.

The step of inserting the large-diameter steel pipes 30 may further include the step of filling the inside of the large-diameter steel pipes 30 with concrete, soil cement or the like. By forming the concrete shell structure surrounded by the large-diameter steel pipe 30, the rigidity of the pillar portion can be greatly increased.

The large-diameter steel pipes 30 inserted into the pillar portion may be connected to each other by a connecting member 32 provided on a side surface thereof. In other words, the large-diameter steel pipes 30 can be connected to each other by forming a concave-convex connection member 32 that can be mutually fitted on the upper and lower sides of the large-diameter steel pipes 30, A structure can be formed. Therefore, the rigid structure of the pillar portion can be formed by the rigidity of the large-diameter steel pipe 30 itself, the strength of the concrete filled in the inside thereof, and the binding force between the upper and lower large-diameter steel pipes 30 by the fitting.

In addition, the large-diameter steel pipes 30 may have through holes 34 formed on both sides thereof at regular intervals along the longitudinal direction so as to pass through in the lateral direction. The through holes 34 may be formed by fastening the plate 36 with bolts or the like or by loosening the bolts directly from the inside of the large diameter steel pipes 30.

The plate 36 can prevent the gravel and the like from flowing through the through holes 34 when the large diameter steel pipes 30 are inserted into the pillar portion and remove the plate 36 after the insertion to remove the concrete, The reinforcing member 50 can be installed between the leading tunnel 10 and the trailing tunnel 20 by filling the inside of the large diameter steel pipes 30. [

The step of installing the shotcrete while drilling the preceding tunnel 10 and installing the steel support material and the reinforcing material 50 may be performed by installing the primary shotcrete 40 while excavating the preceding tunnel 10, Reinforcing materials 50 for reinforcing the pillar portion in the direction of the trailing tunnel 20 are installed and a secondary shotcrete 42 is placed on the upper side of the primary shotcrete 40. [ That is, the primary shotcrete 40 for drilling the preceding tunnel 10, the primary shotcrete 40 for forming the inner wall of the preceding tunnel 10, and the steel support such as the H beam are installed to improve the rigidity of the wall of the preceding tunnel 10 The reinforcing members 50 for reinforcing the pillar portion in the direction of the trailing tunnel 20 are installed and then the second shotcrete 42 is installed.

The stiffener 50 is formed by forming holes through the pillar portion in the direction of the trailing tunnel 20 in the direction of the trailing tunnel 20 on the wall of the primary shotcrete 40 and attaching reinforcement 50 The end portions of the reinforcing bars may be bent, and the reinforcing bars may be integrated with the steel support after being bent and grouting.

The holes for inserting the reinforcing member 50 are formed in the through holes 34 of the large diameter steel pipes 30 because the through holes 34 are previously formed in the large diameter steel pipes 30 and inserted into the pillar portion as described above. Position. Therefore, it is preferable to remove the plate 36 before inserting the large-diameter steel pipe 30 into the pillar portion and filling the concrete or the soil cement in the pillar portion.

The step of installing the shotcrete while drilling the trailing tunnel 20 and installing the steel support material and the reinforcing material 50 is performed by installing the primary shotcrete 40 on the wall while excavating the trailing tunnel 20, Securing the support material, securing the exposed portion of the reinforcing material (50) to the wall surface of the trailing tunnel (20), and pouring the secondary shotcrete (42).

That is to say, in order to drill the trailing tunnel 20 and to install the primary shotcrete 40 for forming the inner wall of the trailing tunnel 20 and to increase the rigidity of the wall of the trailing tunnel 20, The exposed portion of the reinforcing material 50 inserted into the perforation hole is fixed by being fixed to the steel support material and the secondary shotcrete 42 is poured after the support material is installed.

Therefore, in this embodiment, before the excavation of the preceding tunnel 10 and the succeeding tunnel 20 is performed, the pillar portion ground is strengthened by the large-diameter steel pipes 30 connected to each other and filled in the upper and lower sides, The side wall of the tunnel and the large-diameter steel pipes 30 are connected to each other in the transverse direction by the reinforcing material 50 so that the stability of the nearby tunnel having a narrow width of the pillar portion can be remarkably increased.

As described above, by installing the plate 36, the gravel and the like can be prevented from entering into the large-diameter steel pipe 30 when the large-diameter steel pipes 30 having the through holes 34 formed in the filler portion are inserted, The plate 36 is removed and a hole penetrating the preceding tunnel 10 and the trailing tunnel 20 is formed by filling concrete or soil cement or the like and the reinforcing material 50 is inserted and grouted to form the large diameter steel pipe 30, The preceding tunnel 10 and the trailing tunnel 20 can be easily combined with each other.

The reinforcing members 50 are installed to penetrate the through holes 34 of the large diameter steel pipes 30 inserted in the pillar portion in the transverse direction and are connected to the large diameter steel pipes 30, By connecting the trailing tunnel 20, it is possible to form an integrated close-up tunnel filler portion reinforcing structure.

Therefore, this embodiment can secure the stability of the close tunnel construction and prevent the disturbance of the pillar portion ground due to the excavation of the tunnel irrespective of the ground state of the pillar portion. Therefore, the blasting for the excavation of the preceding tunnel 10 and the trailing tunnel 20 The influence of vibration due to blasting can be minimized.

Hereinafter, a reinforcing structure of a pillar portion of a nearby tunnel using a large diameter steel pipe 30 according to an example of the present invention will be described in detail.

The filler portion reinforcing structure of the nearby tunnel using the large diameter steel pipe 30 according to an example of the present invention is a pillar reinforcing structure of a nearby tunnel in which an up tunnel and a down tunnel are installed close to each other, The large diameter steel pipes 30 are installed and connected to the side walls of the preceding tunnel 10 and the rear tunnel 20 through the large diameter steel pipes 30, Can be connected to each other by the connecting member 32 in the direction of the arrow.

The construction of the filler portion reinforcing structure of the nearby tunnel using the large diameter steel pipe 30 is the same as that of the above-described construction method, so that the non-overlapping portions will be mainly described.

The large diameter steel pipes 30 installed in the longitudinal direction may be installed in one row in the vertical direction at the lower portion of the pillar portion and at two rows in the upper side so as to be formed in a Y shape as a whole. The above embodiment is generally applicable to a section where the width of the pillar portion is narrow. That is, the present invention can be applied to a case where the width of the pillar portion is similar to the diameter of the large diameter steel pipe 30.

The reinforcing material 50 installed through the large diameter steel pipe 30 in the present embodiment is installed between the preceding tunnel 10 and the trailing tunnel 20 at the lower side and upwardly fixed to the ground at the upper side.

The large-diameter steel pipes 30 are arranged in two rows in the vertical direction in the pillars, and the large-diameter steel pipes 30 of the respective columns contact each other in the vertical direction, and each row is connected to the preceding tunnel 10 and the trailing tunnel 20 As shown in Fig. This can be applied when the width of the filler portion is larger than twice the width of the large diameter steel pipe 30.

The reinforcing member 50 provided through the large diameter steel pipe 30 in the present embodiment is provided so as to penetrate through two large diameter steel pipes 30 between the leading tunnel 10 and the trailing tunnel 20 at the lower side, And can be fixed to the ground.

The large-diameter steel pipes 30 are installed in three or more rows in the vertical direction in the pillar portion, and each row on both sides of the large-diameter steel pipes 30 is installed in contact with the preceding tunnel 10 and the trailing tunnel 20 . That is, when the large-diameter steel pipes 30 are inserted in three or more columns with a wide width of the pillar portion, both ends are installed in contact with the preceding tunnel 10 and the trailing tunnel 20, .

The reinforcing member 50 provided through the large diameter steel pipe 30 in the present embodiment is provided so as to penetrate through three large diameter steel pipes 30 between the leading tunnel 10 and the trailing tunnel 20 at the lower side, And can be fixed to the ground.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all the constituent elements may be constituted or operated selectively in combination with one or more. Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

10: The preceding tunnel
20: Trailing tunnel
30: Large diameter steel pipe
32: Connector
34: Through hole
36: Plate
40: Primary shotcrete
42: Second shotcrete
50: Stiffener

Claims (13)

A method for constructing a reinforced structure of a pillar portion of a nearby tunnel in which an ascending tunnel and a downward tunnel are installed close to each other,
Inserting large-diameter steel pipes into which the person working in the longitudinal direction of the tunnel can enter;
Installing reinforcing materials for reinforcing the pillar portion in the direction of the trailing tunnel and installing a secondary shotcrete while pouring the primary shotcrete while excavating the preceding tunnel;
Installing the first shotcrete while excavating the trailing tunnel, installing the steel support, fixing the exposed portions of the reinforcement materials, and pouring the second shotcrete,
Wherein the step of inserting the large diameter steel tubes comprises the steps of installing the ground anchors around the point where the large diameter steel tubes are inserted and inserting the large diameter steel tubes while pressing them using the reaction forces of the ground anchors,
Wherein the large diameter steel pipes are installed in contact with the up and down tunnels,
Wherein the reinforcing members are installed through the large-diameter steel pipes inserted in the pillar portion in the lateral direction,
The large-diameter steel pipes inserted into the pillar portion are connected to each other in the vertical direction by a connecting member provided on the side surface thereof,
The large-diameter steel pipes are formed with through-holes passing through in the lateral direction at regular intervals along the longitudinal direction. The through-holes are closed by plates provided inside the large-diameter steel pipes, And the through holes can be opened by a person to remove the through holes. The method for constructing the close tunnel filler portion reinforcing structure using the large diameter steel pipe.
delete The method according to claim 1,
The step of inserting the large-
And inserting the large-diameter steel pipes while inserting the inside of the large-diameter steel pipes.
The method according to claim 1,
After the step of inserting the large diameter steel tubes,
And filling the inside of the large diameter steel pipes with concrete or soil cement.
delete delete The method according to claim 1,
The provision of the reinforcements,
And forming grooves through the large-diameter steel pipes from the preceding tunnel to the trailing tunnel, and inserting reinforcing bars into the holes, and then performing grouting.
In a reinforced structure of a pillar portion of a nearby tunnel in which an ascending tunnel and a descending tunnel are installed close to each other,
Large-diameter steel pipes inserted into the pillar portion in the longitudinal direction of the tunnel and capable of entering a person working thereon;
And reinforcing members penetrating the large-diameter steel pipes and joined to the sidewalls of the preceding tunnel and the rear tunnel,
The large-
The pillar portion is provided in one row in the vertical direction and separated from the pillar portion in two rows so as to be installed in contact with the preceding tunnel and the trailing tunnel while being installed in a Y shape as a whole, Wherein each column of the large diameter steel pipes is installed in contact with the preceding tunnel and the trailing tunnel or in three or more columns in the vertical direction at the pillars, A second tunnel installed in contact with the tunnel,
The large-diameter steel pipes are formed with through-holes passing through in the lateral direction at regular intervals along the longitudinal direction. The through-holes are closed by plates provided inside the large-diameter steel pipes, It is possible to directly remove the through hole by a person,
Wherein the reinforcing materials are installed through the through holes of the large diameter steel pipes inserted in the pillar portion in the lateral direction,
Wherein the large-diameter steel pipes are connected to each other by vertically connecting members by a connecting member.
delete delete delete delete delete

Images