KR20180110887A - Construction methods of approaching dual tunnel - Google Patents

Abstract

Disclosed is a construction method for a near parallel tunnel, adjacently constructing two tunnels to enable the ground between adjacent two tunnels to act as a pillar. According to the present invention, the construction method for a near parallel tunnel improves a construction method to reinforce the ground of a pillar unit and a surface of the pillar unit and excavate a tunnel, simultaneously. Therefore, the present invention reduces a construction period and costs and improves construction efficiency.

Description

{Construction methods of approaching dual tunnel}

The present invention relates to a method of constructing a tunnel, and more particularly, to a method of constructing a close-coupled tunnel in which two tunnels are closely installed so that a ground between adjacent two tunnels serves as a pillar.

In the case of a parallel tunnel with two tunnels in parallel, a tunnel is usually installed at a sufficient distance between the tunnel and the tunnel for the structural stability of the tunnel. In this case, to ensure the structural stability of the tunnel, the distance between the separated tunnels is 1.5 times or more based on the tunnel excavation width, though there is a difference depending on the ground condition.

However, it is not easy to secure a distance of 1.5 times or more of the tunnel excavation width due to other conditions such as the terrain condition of the tunnel construction site and environmental problems. In this case, the tunnel is excavated using a two-arched tunnel excavation method in which a central tunnel is first formed at a central portion where two tunnels are to be formed, and a central wall (usually a concrete column) have.

In the arch tunneling method, a central tunnel is first constructed at the central part where two tunnels are to be formed, and then a main tunnel is formed. However, this method is disadvantageous in that the construction is complex, the air is long, and the construction cost is high, by constructing the central tunnel for forming the center wall and then extending the main tunnel in succession.

There is also a construction method in which a large tunnel consisting of one arch is excavated and a column or a wall is formed at the center. However, this construction method requires a column or a wall for efficient ventilation and median separation due to the traffic on the opposite side. Therefore, the width of the tunnel is inevitably widened by more than 1.0 ~ 1.5m compared with the existing 4th tunnel, There is a drawback that it becomes vulnerable.

In order to solve this problem, a close-coupled tunnel construction method has been proposed in which the pillar portion between the tunnel and the tunnel is kept narrower than the width of the tunnel while allowing excavation and reinforcing the pillar portion to secure stability. Among the close-coupled tunnel method, a method of isolating the blasting part and the pillar part and then excavating the tunnel through blasting is known to minimize the blasting impact of the blasting part.

Korean Patent Laid-Open Publication No. 2014-0017469 discloses a water jet excavation method in which water is blown at a high pressure using a nozzle on a planned pillar surface to form a space with a predetermined width on a surface partitioning the pillar portion, This is a method to prevent the pillar portion from being damaged or destroyed because it is not transmitted to the pillar portion due to the space.

However, Korean Patent Laid-Open Publication No. 2014-0017469, a tunnel excavation technique using a water jet, points out that there is a limitation in depth and width of excavation that can be drilled by high pressure injection through a nozzle. In addition, there is a problem that a lot of water is used and the working environment is polluted due to the water, and there is a problem that the air is lengthened due to a long time, and the construction cost is large.

Another construction method proposed in Korean Patent Registration No. 10-1391218 as a close-coupled tunnel construction technique is exemplified. The technique disclosed in Korean Patent Registration No. 10-1391218 is a technique in which a preceding tunnel is excavated through blasting at a planned excavation size, excavation of a portion excluding a portion up to 2 m from the pillar portion by blasting, to be.

However, in Korean Patent Registration No. 10-1391218, when the tunnel is excavated, the blasting impact is generated due to the cracks or dropping of the pillar portion to a certain depth, so that it is structurally unstable due to the subsequent process in the state where the breakage is present, And the other part is further excavated after excavation to form a pillar part which becomes a column between the two tunnels.

Meanwhile, there is also known a technique of reinforcing the pillar portion and increasing the structural stability of the pillar portion by padding an arcuate reinforcing block on the pillar portion exposed in the tunnel excavation process. This is a method that is used when additional pillar reinforcement is required because excavation ground is not sufficiently rigid. It is a method of constructing a reinforced block by securing a space by further excavating the pillar side ground than the planned excavation surface.

However, this is because the tunnel is excavated in the planned depth and direction and then the excavation surface is further excavated to secure the space and the reinforcing block is attached to the excavation surface. Thus, the efficiency of construction is inferior, And the additional excavation of the pillar side foundation for constructing the reinforced block is carried out separately, thereby pointing out that there is a lot of equipment and manpower consumption.

Korean Patent Registration No. 10-1234814 (Registered on March 2, 2013)

The problem to be solved by the present invention is to improve the construction method of the close-coupled tunnel so that the reinforcement of the pillar portion and the pillar portion together with the tunnel excavation can be performed together, .

According to an aspect of the present invention as a means for solving the problems,

(a) a preceding tunnel excavation step of excavating the preceding tunnel to a certain depth;

(b) forming a reinforcing surface of a preceding tunneling pillar portion forming a reinforcing surface of the pillar portion of the preceding tunnel by blasting or cutting the pillared portion at a predetermined depth in an inclined manner from the excavation end surface of the preceding tunnel to the trailing tunnel direction;

(c) a first pillar portion reinforcing space for further excavating a preceding tunnel at a depth corresponding to the reinforcing surface of the preceding tunnel pillar portion and excavating a pillar portion facing the reinforcing surface of the preceding tunnel pillar portion to increase the cross- A first pillar reinforcing space forming step of forming a first pillar reinforcing space;

(d) reinforcing the pillar portion by drilling the reinforcing hole in the horizontal direction from the leading tunnel to the trailing tunnel through the reinforcing surface of the preceding tunnel pillar portion, inserting the reinforcing material, and grouting to reinforce the pillar portion;

(e) sealing the first pillar reinforcing space with mortar or shotcrete to form a first pillar reinforcing wall;

(f) a trailing tunnel excavating step of excavating a trailing tunnel adjacent to the preceding tunnel with a pillar portion therebetween;

(g) a step of forming a reinforcing surface of a trailing tunnel pillar portion forming a reinforcing surface of a pillar portion of a trailing tunnel by drilling or cutting a pillared portion at a predetermined depth in an inclined manner from the excavation end surface of the trailing tunnel to a preceding tunnel;

(h) a second pillar reinforcement space for further drilling a trailing tunnel at a depth corresponding to the trailing tunnel pillar portion reinforcing surface, and for excavating a pillar portion facing the trailing tunnel pillar portion reinforcing surface, A second pillar reinforcing space forming step of forming a second pillar reinforcing space;

(i) a stiffener fixing step of fixing one end of a reinforcing member installed in a preceding tunnel to the trailing tunnel pillar portion reinforcing surface in the pillar reinforcing step; And

(j) a second pillar reinforcing wall forming step of sealing the second pillar reinforcing space with mortar or shotcrete to form a second pillar reinforcing wall,

There is provided a method of constructing a near-lined tunnel by repeating the steps (b) to (e) and the steps (g) to (j)

The steps (a) and (f) may include: forming a pillar surface by forming a pillar portion and forming a pillar surface by drilling or cutting a boundary between a leading tunnel or a trailing tunnel and a pillar portion at a predetermined depth in a bending direction; And a tunnel excavation step of excavating a preceding tunnel or a following tunnel to a depth corresponding to the pillar surface.

In addition, one or more columns of steel tubes may be installed at predetermined intervals toward the pumping direction along the planned excavation schedule line in the shaft section before the pillar surface forming step, and the ends of the steel tubes projecting out of the shaft section may be formed It is possible to construct the gang form by placing the concrete in the condition that it is constrained to the frame.

Reinforcing a preceding tunnel excavation surface between the steps (a) and (b), wherein the excavation surface of the preceding tunnel is reinforced by installing the support material at a predetermined interval on the excavation surface of the preceding tunnel; And reinforcing the pillar portion between the preceding tunnel and the trailing tunnel to be excavated after the reinforcing hole is drilled in the horizontal direction from the preceding tunnel to the trailing tunnel through the preceding tunnel pillar surface, and the reinforcing material is inserted and grouted. A step of reinforcing the excavation surface of the trailing tunnel by installing the support material at a predetermined interval on the excavation surface of the trailing tunnel between the steps (f) and (g); And a stiffener fixing step of fixing one end of the reinforcing member installed in the preceding tunnel to the pillar surface of the trailing tunnel.

At this time, it is possible to reinforce the excavation surface by connecting the reinforcing bars or wire mesh between the support material installed on the excavation surface of the preceding tunnel and the trailing tunnel, and then injecting the shotcrete.

Further, after steps (e) and (j), after the step (e) and step (j), the support members are installed at the excavation surfaces of the additional tunnel and the rear tunnel at regular intervals, and the support members are connected by the deformed reinforcing bars or wire mesh, Additional excavation surfaces can be reinforced.

Here, it is preferable that a downward stiffener is provided so as to face downward from the bottom of both sides of the tunnel facing opposite ends of the support, and both ends of the support are fastened to the upper end of the downward stiffener to fix the support.

Preferably, the elevation means is provided at a portion where the support member and the downward stiffener are connected to each other, so that the support member is lifted up against the downward stiffener so as to be brought into close contact with the excavation surface.

After the steps (a) and (c), one or more rock bolts are installed on the pillar portion and the pillar portion reinforcing surface of the preceding tunnel so as to face the trailing tunnel. After the steps (f) and (h) One or more rock bolts may be installed on the pillar portion of the tunnel and the reinforcing portion of the pillar to face the preceding tunnel to prevent rock collapse on the pillar portion and the pillar portion.

According to the method for constructing a close-proximity tunnel according to the present invention, the first face is excavated at a predetermined depth in the shaft portion of the tunnel, and then the pillar portion is perforated or cut at a predetermined depth in an inclined direction from the excavation to the relative tunnel, The space is formed to isolate the blasting part and the pillar part. Accordingly, it is possible to prevent damage to the pillar surface or displacement of the pillar portion due to the blasting impact at the time of excavation.

In addition, a pillar reinforcing space having an arbitrary width and area is formed by excavation by a pillar reinforcing surface formed together with a blasting shock blocking space, and mortar or shotcrete is poured therein to form a pillar reinforcing wall. As a result, additional excavation of the side surface of the excavation surface for reinforcement of the pillar portion and the pillar portion can be omitted. As a result, air shortening, cost reduction, and efficient construction can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a construction procedure of a close-coupled tunnel construction method according to the present invention; FIG.
FIGS. 2 to 17 are detailed views of steps in accordance with the method of constructing a close-coupled tunnel according to the present invention.
18 is a plan view of a pillar portion of a tunnel constructed through a construction method according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a view showing a construction procedure of a close-coupled tunnel construction method according to the present invention.

Referring to FIG. 1, the present invention provides a method for constructing a tunnel structure, including a preceding tunnel excavation step S10, a preceding tunnel pillar reinforcing surface forming step S20, a first pillar reinforcing space forming step S30, a pillar reinforcing step S40, 1-pillar reinforcing wall forming step (S50). In addition, it is also possible to perform the following steps (S60), (S70), (S80), (S80), (S90) and (S100) the second pillar reinforcing wall forming step ).

The construction method according to the present invention includes the steps of S20 to S50 as the tunneling and pillar reinforcement processes of the preceding tunnel 1 and the pillar reinforcement along the tunnel advancing direction, The rock bolt 8 is installed in order to prevent the rocks of the pillar surface 11 and the pillar reinforcing surface 14 from collapsing, And forming a part (4).

The steps of the method of constructing the close-coupled tunnel according to the present invention will be described in more detail with reference to FIG. 2 to FIG.

The preceding tunnel excavation step S10 is a step of excavating the preceding tunnel 1 to a predetermined depth from the shank portion 4 which becomes an entrance at the time of tunnel excavation. The preceding tunnel excavation step S10 is preferably performed after the formation of the tunnel shaft portion 4 so that the boundary of the pillar portion 3 to be formed between the portion to be excavated in the preceding tunnel 1, (A pillar surface forming step) (Fig. 2 (b)) in which the pillar surface 11 is formed by piercing or cutting the pillar surface 1 at a depth of 3 m to 30 m.

In the pillar surface forming step, the pillar surface 11 can be formed by using a known perforating equipment or cutting equipment. (Blasting shock blocking space 12) between the blasting section 15 and the pillar section 3, and a pillar section 12 between the blasting section 15 and the pillar section 3 by drilling the pillar section 3 with a small pore size along the boundary (excavation boundary line) Line-drilling to form the side surface 11 may be used. In addition, slot drilling or wire sawing can be used.

The preceding tunnel excavation step S10 may also be performed at a depth corresponding to the pillar surface 11 formed at the pillar surface forming step after the pillar surface forming step, preferably at the depth of one pillar surface (D1, 3m to 30m) (A tunnel excavation step, Fig. 2 (c)), in which the preceding tunnel 1 is fully excavated. Preliminary Tunnel (1) For excavation, a general blasting technique can be used to excavate a tunnel through blasting using explosives.

The blasting method is a method in which, for example, a charging hole (drilling area) 15 partitioned by a pillar portion 3 with a pillar surface 11 (or a predetermined isolation space) And charging the explosives into the chargeable hall, and then blasting and excavating it. At this time, the influence of the blasting shock on the pillar 3 due to the predetermined isolation space formed between the pillar portion 3 and the blasting portion 15 through the previous step (Fig. 2 (b)) can be minimized .

That is, due to the blasting shock blocking space 12 formed between the blasting part 15 and the pillar part 3 in the pillar forming step, the blasting impact generated when the blasting excavation is performed on the excavation area, Can be minimized. As a result, it is possible to prevent damage or breakage such as cracks in the pillar portion 3 or the pillar portion 11 due to the blasting impact at the time of blasting excavation.

The number or spacing of the charging ports into which explosives are charged for blasting excavation to the blasting section 15 may vary depending on the quality of the rock, the blasting method, or the explosive force of the explosive. Preferably, the blasting part may be formed at regular intervals over the entire surface of the blasting part, and a size sufficient to charge the explosive is sufficient.

And forming gang phrases before the pillar surface formation step. The gang construction is preferably such that one or more columns of steel tubes 5 are installed at predetermined intervals toward the excavation direction along a planned excavation schedule line in the shaft section 4 and a steel pipe 5 protruded outside the shaft section 4, (Fig. 2 (a)). In this case, the concrete structure is formed by placing the ends of the concrete structures in a state where the ends of the concrete structures are constrained to the frame forming the gang construction.

A process of reinforcing the excavation surface 13 and the pillar portion 3 after the preceding tunnel 1 is excavated through the preceding tunnel excavation step S10 can be performed. In the preceding tunnel excavation surface reinforcing step (S12, Fig. 3), arcuate support members 6 corresponding to the shape of the excavating end surface 10 are provided at regular intervals on the excavation surface, and a thickness at which the support members 6 can be embedded It is possible to consider a known method in which the shotcrete C is installed to prevent and reinforce the excavation surface.

In the case where the ground is soft, that is, in the case of soft ground, a process of adding a ground reinforcement material such as anchor bolt 8 or anchor to the excavation surface 13 in the normal direction may be added around the excavation surface 13 have. That is, a ground reinforcement material such as a rock bolt 8 or anchor may be installed on the excavation surface 13 to prevent rock collapse on the excavation surface and reinforce the ground around the excavation surface.

It is possible to connect the support members 6 provided on the excavation face 13 of the preceding tunnel 1 with the deformed reinforcing bars or the wire meshes 70 at regular intervals and then connect the support members 6 and the deformed reinforcing bars 6, The excavation surface may be reinforced by pouring the shotcrete to a thickness at which the wires can be buried at the same time. Of course, it can also include all known methods used for excavation reinforcement.

In the case of the support 6 used for reinforcing the excavation surface, a downward stiffener 7 is provided so as to face downward from the bottom edge of both sides of the tunnel where both ends of the support 6 face each other, Both ends of the support 6 may be connected to the upper end of the downward stiffener 7 so that the support 6 can be firmly fixed without shaking in a state in which the support 6 is in close contact with the excavation surface.

The elevating means may be provided at a portion where the support 6 and the downward stiffener 7 are connected to each other. The elevating means lifts the support 6 up against the downward stiffener 7 to be brought into close contact with the excavation surface 13 so that the support 6 can stably support the load of the excavation site. And may include any structure capable of adjusting the spacing of the support 6 with respect to the downward stiffener 7 including the height adjustment structure.

It is possible to reinforce the pillar portion 3 by installing the reinforcing member 32 in the horizontal direction toward the trailing tunnel 2 in the preceding tunnel 1 before the shotcrete pouring for reinforcing the excavation surface. Preferably, the reinforcing hole 30 is pierced in the horizontal direction toward the trailing tunnel 2 through the pillar surface 11 of the preceding tunnel 1, the reinforcing member 32 is inserted, and grouting is performed to connect the preceding tunnel 1 ) And the trailing tunnel 2 to be excavated thereafter can be reinforced with respect to the pillar portion 3.

The preceding tunnel pillar reinforcing surface forming step S20 is a process of fully excavating the tunnel from the excavation end surface 10 of the preceding tunnel 1 excavated at the depth of one tunnel. In this step, the pillar portion 3 is pierced or cut at a certain depth in an inclined manner in the direction of the trailing tunnel 2 from the excavation end face 10 of the already-excavated preceding tunnel 1 to form the blasting shock blocking space 12 and the preceding tunnel 1 (Fig. 5). Referring to Fig.

The same method as in the formation of the pillar surface 11 described above can be used to form the bladelight impact blocking space 12 and the pillar portion reinforcing surface 14 of the preceding tunnel 1. Line-drilling may be used to drill holes from the excavation end face 10 in small pores so that the blasting shock isolation space 12 and the pillar reinforcing surface 14 are formed between the blasting part and the pillar part . Other slot-drilling or wire saws may be used.

The first pillar reinforcing space forming step S30 (FIG. 6) is a step of forming the first pillar reinforcing space 16 on the pillar portion 3 side of the preceding tunnel 1. In the first pillar portion reinforcing space forming step S30, the preceding tunnel 1 is further excavated to a depth corresponding to the preceding tunnel pillar portion reinforcing surface 14 in the previous step, and at the same time the preceding tunnel pillar portion reinforcing surface 14 And the first pillar reinforcing space 16 having a larger cross-sectional area is formed in the pumping direction.

The excavation of the pillar portion 3 facing the preceding tunnel 1 and the pillar portion reinforcing surface 14 at a depth corresponding to the pillar portion reinforcing surface 14 can be performed by the above-described blasting method. Of course, since a predetermined isolation space (blasting shock blocking space 12) is formed between the blasting drill sections on the pillar portion 3 side through the previous preceding tunnel pillar reinforcing surface forming step S20, the blasting shock for excavation Can be prevented from affecting the pillar portion (3).

When the formation of the first pillar reinforcing space 16 is completed, the pillar reinforcing step S40 may be performed successively (Fig. 7). The pillar portion reinforcing step (S40) is the same as the reinforcement of the upper pillar portion (3). The reinforcing hole 30 is drilled in the horizontal direction from the preceding tunnel 1 to the trailing tunnel 2 through the pillar reinforcing face 14 and the reinforcing member 32 is inserted into the reinforcing hole 30, Thereby reinforcing the ground of the pillar portion 3 where the first pillar portion reinforcing space 16 is formed.

A process of installing a ground reinforcement such as one or more rock bolts or anchors to the posterior tunnel 2 on the pillar reinforcement surface 14 may be added before and after the pillar reinforcement step S40 have. That is, a ground reinforcement material such as a rock bolt or anchor is installed in the direction of the trailing tunnel 2 through the pillar reinforcing surface 14 to prevent rock collapse of the pillar reinforcing surface 14 and to reinforce the surrounding ground .

The first pillar reinforcing wall forming step S50 (FIG. 8) is a step of forming the first pillar reinforcing wall 34 by sealing the first pillar reinforcing space 16 (see FIG. 7) with mortar or shotcrete . That is, the mortar or shotcrete is poured into the first pillar portion reinforcing space 16 and the first pillar reinforcing wall 34 (corresponding to the first pillar portion reinforcing space 16) ).

After the formation of the first pillar reinforcing wall 34, the support members 6 are provided on the excavation face 13 of the additional pre-drilled first tunnel 1 at regular intervals, The excavation surface 13-1 having the first pillar reinforcing wall 34 formed thereon can be reinforced by pouring the shotcrete after the pillar 70 is connected to the excavation surface (FIG. 9). Of course, it can also include all known methods used for excavation reinforcement.

3, a downward stiffener 7 is provided so as to face downward from the bottom edge of both sides of the tunnel facing opposite ends of the support 6, and the upper end of the downward stiffener 7 It is preferable that both ends of the support 6 are fastened to each other so that the support 6 can be firmly fixed without shaking in a state in which the support 6 is in close contact with the excavation surface.

Further, the lifting means may be provided at a portion where the support 6 and the downward stiffener are connected to each other, so that the support 6 is lifted up against the downward stiffener so that the support 6 is strongly adhered to the excavation surface. In this case, the elevating means may also include any means capable of adjusting the spacing of the support material with respect to the downward stiffener, including the height adjustment structure composed of bolt-nuts as described above.

The trailing tunnel excavation step (S60, FIG. 10) is a step of excavating the trailing tunnel 2 from the shaft portion 4 to a certain depth. The trailing tunnel excavation step S60 is preferably performed at a predetermined depth in the bending direction, for example, at a depth of 3m to 30m (for example, 1m) at the boundary between the tunneling section and the tunneling section, To form a pillar surface 21 (pillar surface forming step).

In the pillar surface forming step, the pillar surface 21 can be formed using a known perforating equipment or cutting equipment (Fig. 10 (a)). (Blasting shock blocking space 22) between the blasting section 25 and the pillar section 3 and the pillar section 3 between the pillar section 3 and the pillar section 3 by, for example, Line-drilling to form the side surface 21 may be used.

Of course, slot-drilling or wire sawing may be used.

The trailing tunnel excavation step S60 is also performed after the pillar surface forming step to a depth corresponding to the pillar surface 21 formed in the pillar surface forming step, preferably to the depth of one pavement (3 m to 30 m) (A tunnel excavation step, FIG. 10 (b)) in which the excavator 2 is fully excavated. Trailing tunnel (2) Excavation General blasting techniques can also be used to excavate tunnels through blasting using explosives.

A process of reinforcing the excavation surface after the excavation of the trailing tunnel 2 through the trailing tunnel excavation step S60 may be performed. In the step of reinforcing the excavation surface 23 of the trailing tunnel 2, arcuate support members 6 corresponding to the shape of the excavation end surface 10 are installed at a predetermined interval on the excavation surface, and the support members 6, It is considered that a shotcrete (C) is installed in a thickness to prevent and reinforce the excavation surface (Fig. 11).

Likewise, when the ground is soft, that is, when it is a soft ground, a process of adding a ground reinforcement material such as a rock bolt 8 or anchor in the normal direction to the excavation surface around the excavation surface may be added. In other words, a rock bolt (8) or a ground reinforcement such as anchor may be installed on the excavation surface to prevent rock collapse on the excavation surface and reinforce the ground around the excavation surface.

It is possible to connect the support members 6 provided on the excavation face 13 of the preceding tunnel 1 with the deformed reinforcing bars or the wire meshes 70 at regular intervals and then connect the support members 6 and the deformed reinforcing bars 6, The excavation surface may be reinforced by pouring the shotcrete to a thickness at which the wires can be buried at the same time. Of course, it can also include all known methods used for excavation reinforcement.

The support members 6 used for reinforcing the excavation surface are also provided with downward stiffeners 7 so as to face downward from the bottom edges of the both sides of the tunnel facing both ends of the support members 6, Both ends of the support 6 may be tied together so that the support 6 can be firmly fixed in a state of tight contact with the excavation surface (see FIG. 3 attached heretofore).

The elevating means may be provided at a portion where the support 6 and the downward stiffener are connected to each other. The elevating means includes a height adjusting structure composed of a bolt-nut so that the support 6 can be stably supported by the support 6 by lifting the support 6 up against the downward stiffener and coming into close contact with the excavation surface And may include any means capable of adjusting the spacing of the support 6 with respect to the downward stiffener.

One end of the reinforcing member 32 provided in the horizontal direction from the preceding tunnel 1 to the rear tunnel 2 before the shotcrete pouring for reinforcing the excavation surface 23 of the trailing tunnel 2 (The end of the reinforcing member 32 exposed) to the pillar surface 21 of the trailing tunnel 2 can be performed. At this time, for fixing the stiffener 32 to the pillar surface 21 of the trailing tunnel 2, a fixing head (not shown) having a support plate and a nut structure may be used (S64).

The trailing tunnel pillar reinforcing surface forming step S70 (FIG. 13) is performed in the trailing tunnel 2 from the excavation end surface 20 of the trailing tunnel 2, Is an excavation process. In this step, the pillar portion 3 is pierced or cut at a certain depth in an inclined manner in the direction of the trailing tunnel 2 from the excavation end face 20 of the already-trailing trailing tunnel 2 to form the blasting shock blocking space 22 and the trailing tunnel 2 The reinforcing surface 24 of the pillar portion can be formed.

The blasting shock isolation space 22 and the pillar reinforcing surface 24 of the trailing tunnel 2 can be formed in the same manner as in the formation of the pillar surface 21 described above. The piercing portion 25 and the pillar portion 3 are closely pierced with a small pore along the pillar 3 boundary (excavation boundary line) so that the blasting shock blocking space 22 and the pillar reinforcing surface 24 are formed. Line drilling may be used.

The second pillar reinforcing space forming step S80 (FIG. 8) is a step of forming the second pillar reinforcing space 26 on the pillar portion 3 side of the trailing tunnel 2. In the second pillar portion reinforcing space forming step S80, the trailing tunnel 2 is further excavated to a depth corresponding to the trailing tunnel pillar portion reinforcing surface 24 in the previous step, and the trailing tunnel pillar portion reinforcing surface 24 And the second pillar reinforcing space 26 having a larger cross-sectional area is formed in the pumping direction.

Excavation of the trailing tunnel 2 at a depth corresponding to the pillar portion reinforcing surface 24 and excavation of the pillar portion 3 facing the trailing tunnel pillar portion reinforcing surface 24 can be performed by the above-described blasting technique. Of course, since a predetermined isolation space (blasting shock blocking space, 22 in FIG. 13) is formed between the blasting excavation portions on the pillar portion 3 side through the preceding rear tunnel pillar reinforcing surface forming step S70, The impact on the pillar portion 3 can be blocked.

When the formation of the second pillar portion reinforcing space 26 is completed, the stiffener fixing step S90 may be performed successively (Fig. 15). The stiffener fixing step S90 is the same as the preceding step S64. That is, in the process of fixing one end portion of the reinforcing member 32 already provided in the horizontal direction from the preceding tunnel pillar portion reinforcing face 14 toward the trailing tunnel 2 to the pillar portion reinforcing face 24 of the trailing tunnel 2, A fixing head (not shown) having a support plate and a nut structure can be used for fixing the reinforcement 32 to the pillar reinforcing face 24 of the trailing tunnel 2. [

A ground reinforcement material such as one or more rock bolts or anchors may be installed on the pillar reinforcement surface 14 of the trailing tunnel 2 so as to face the preceding tunnel 1 before and after the reinforcing material securing step S90 The process can be added. That is, a ground reinforcement material such as a rock bolt or anchor is installed in the direction of the preceding tunnel 1 through the pillar reinforcing face 14 to prevent rock collapse of the pillar reinforcing face 24 and reinforce the surrounding ground .

The second pillar reinforcing wall forming step S100 (FIG. 16) is a step of forming the second pillar reinforcing wall 36 by sealing the second pillar reinforcing space 26 with mortar or shotcrete. That is, the mortar or shotcrete is poured into the second pillar portion reinforcing space 26 to form the second pillar reinforcing wall 36 (corresponding to the second pillar portion reinforcing space 26) ).

After the formation of the second pillar reinforcing wall 36, the support members 6 are installed on the excavation surface 23 of the further excavated trailing tunnel 2 at regular intervals, The additional excavation surface 23-1 in which the second pillar reinforcing wall 36 is formed can be reinforced by pouring the shotcrete C after connecting the excavator 70 to the excavation surface. Of course, any known method used for excavation reinforcement may be used.

Likewise, a downward stiffener 7 (see Fig. 3 attached heretofore) is provided so as to face the bottom of both sides of the tunnel facing both ends of the support 6, and the amount of the support 6 So that the support 6 can be firmly fixed without shaking in a state in which the support 6 is in close contact with the excavation surface and the aforementioned elevating means can be provided between the support 6 and the downward stiffener.

FIG. 18 is a plan view of a pillar portion of a tunnel constructed through the construction method according to the present invention. In the construction method according to the present invention, after the first pillar portion, The displacement of the pillar portion can be more reliably prevented and the structural stability of the pillar portion 3 can be further increased.

According to the method of constructing the close-proximity tunnel according to the present invention, the first surface is excavated at a predetermined depth in the shaft portion of the tunnel, and then the pillar portion is drilled or cut at a predetermined depth in an inclined direction from the excavation to the relative tunnel, A blocking space is formed to isolate the blasting part and the pillar part. Accordingly, it is possible to prevent damage to the pillar surface or displacement of the pillar portion due to the blasting impact at the time of excavation.

In addition, a pillar reinforcing space having an arbitrary width and area is formed by excavation by a pillar reinforcing surface formed together with a blasting shock blocking space, and mortar or shotcrete is poured therein to form a pillar reinforcing wall. As a result, additional excavation of the side surface of the excavation surface for reinforcement of the pillar portion and the pillar portion can be omitted. As a result, air shortening, cost reduction, and efficient construction can be achieved.

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

1: preceding tunnel 2: trailing tunnel
3: pillar portion 4: shaft portion
5: Steel pipe 6: Support material
7: Downward stiffener 8: Lock bolt
10, 20: excavation section 11, 21: pillar section
12, 22: Blasting shock blocking space 13, 23: Excavation surface
13-1, 23-1: Additional excavation surface
14, 24: reinforcement surface of the pillar portion
15, 25: Blasting part
16: first pillar portion reinforcing space
26: Second pillar portion reinforcing space
34: first pillar reinforcing wall
36: second pillar portion reinforcing wall

Claims (9)

(a) a preceding tunnel excavating step (SlO) of excavating the preceding tunnel 1 to a predetermined depth;
(b) The pillar portion 3 is pierced or cut at a predetermined depth in a direction inclined in the direction of the trailing tunnel 2 from the excavation end face 10 of the preceding tunnel 1 to form a pillar of the pillar of the preceding tunnel 1, A preceding tunnel pillar portion reinforcing surface forming step (S20) forming the auxiliary reinforcing surface (14);
(c) The preceding tunnel 1 is further excavated to a depth corresponding to the preceding tunnel pillar portion reinforcing surface 14 and the pillar portion 3 facing the preceding tunnel pillar portion reinforcing surface 14 is excavated and pushed A first pillar reinforcing space forming step (S30) for forming a first pillar reinforcing space (16) having an increased sectional area in a direction toward the first pillar portion;
(d) The reinforcing hole (30) is punctured in the horizontal direction from the preceding tunnel (1) to the trailing tunnel (2) through the preceding tunnel pillar portion reinforcing surface (14) A pillar reinforcing step (S40) for reinforcing the part (3);
(e) forming a first pillar reinforcing wall (S50) by sealing the first pillar reinforcing space (16) with mortar or shotcrete to form a first pillar reinforcing wall (34);
(f) a trailing tunnel excavation step (S60) of excavating the trailing tunnel (2) adjacent to the preceding tunnel (1) with the pillar (3) interposed therebetween;
(g) The pillar portion 3 is pierced or cut at a certain depth in an inclined manner in the direction of the preceding tunnel 1 at the excavation end face 20 of the trailing tunnel 2 to form the pillar of the blasting shock blocking space 22 and the trailing tunnel 2 A step of forming a trailing tunnel pillar portion reinforcing surface (S70) for forming the auxiliary reinforcing surface (24);
(h) The trailing tunnel 2 is further excavated to a depth corresponding to the trailing tunnel pillar portion reinforcing surface 24, and the pillar portion 3 facing the trailing tunnel pillar portion reinforcing surface 24 is excavated, A second pillar reinforcing space forming step (S80) for forming a second pillar reinforcing space (26) having an increased cross sectional area toward the second pillar reinforcing space (26);
(i) a stiffener fixing step (S90) of fixing one end portion of the reinforcing member (32) provided in the preceding tunnel (1) to the trailing tunnel pillar portion reinforcing surface (24) in the pillar reinforcing step (S40); And
(j) forming a second pillar reinforcing wall (36) by sealing the second pillar reinforcing space (26) with mortar or shotcrete; and forming a second pillar reinforcing wall (S100)
(B) to (e) and (g) to (j) are alternately repeated along the tunneling direction of the tunnel to construct a tunnel.
The method according to claim 1,
The steps (a) and (f)
The pillar sections 11 and 21 are formed by forming the shaft section 4 and drilling or cutting the boundary between the preceding tunnel 1 or the trailing tunnel 2 and the pillar section 3 in the pumping direction at a predetermined depth A pillar surface forming step; And
And a tunnel excavating step of excavating the preceding tunnel (1) or the trailing tunnel (2) at a depth corresponding to the pillar surface (11) (21).
3. The method of claim 2,
One or more steel pipes 5 are installed in the shaft portion 4 along the planned excavation schedule line at predetermined intervals toward the pumping direction before the pillar surface forming step and the steel pipe 5 protruded to the outside of the shaft portion 4 5) are constrained to the frame forming the gang construction, and the concrete is laid to form the gang construction.
The method according to claim 1,
Between steps (a) and (b) above,
A preceding tunnel excavation surface reinforcement step (S12) in which the support members (6) are provided at regular intervals on the excavation surface (13) of the preceding tunnel (1) to reinforce the excavation surface (13) of the preceding tunnel (1); And
A reinforcing hole 30 is drilled in the horizontal direction from the preceding tunnel 1 to the trailing tunnel 2 through the pillar surface 11 of the preceding tunnel 1 and the reinforcing material 32 is inserted and grouted, (S40) reinforcing the pillar portion (3) between the pillar portion (1) and the trailing tunnel (2) to be excavated thereafter,
Between steps (f) and (g)
A rear tunnel excavation surface reinforcement step (S62) in which the support members (6) are provided on the excavation surface (23) of the trailing tunnel (2) at regular intervals to reinforce the excavation surface (23) of the trailing tunnel (2); And
And a stiffener fixing step (S64) of fixing one end of the reinforcing member (32) installed in the preceding tunnel (1) to the pillar surface (11) of the trailing tunnel (2).
5. The method of claim 4,
The excavation surfaces 13 (23) of the preceding tunnel (1) and the trailing tunnel (2) are connected by a deformed reinforcing bar or wire mesh (70) 23) is reinforced.
The method according to claim 1,
After the steps (e) and (j)
The support members 6 are provided at regular intervals on the excavation surface 23 of the preceding tunnel 1 and the trailing tunnel 2 of the additional excavation and the portions between the support members 6 are connected by a deformed reinforcing bar or wire mesh 70 And the additional excavation surfaces (13-1) and (23-1) are reinforced by pouring the after shotcrete.
The method according to claim 4 or 6,
A downward stiffener 7 is provided so as to face downward from the bottom of both sides of the tunnel where both ends of the support 6 face each other and both ends of the support 6 are fastened to the upper end of the downward stiffener 7, (6) are fixed to each other.
8. The method of claim 7,
And a lifting means for lifting up the support material (6) to the downward stiffener (7) is provided at a portion where the support (6) and the downward stiffener (7) are connected to each other.
The method according to claim 1,
After the steps (a) and (c), at least one rock bolt 8 is installed on the pillar portion 11 and the pillar portion reinforcing surface 14 of the preceding tunnel 1 so as to face the trailing tunnel 2 ,
At least one rock bolt 8 is installed on the pillar portion 11 and the pillar portion reinforcing surface 14 of the trailing tunnel 2 so as to face the preceding tunnel 1 after the steps (f) and (h) Wherein the method comprises the steps of:

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