JP2007077677A - Construction method for underground structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a construction method for an underground structure, capable of easily and promptly constructing the underground structure superior in water cut-off performance, constructed by using a plurality of juxtaposed tunnels. <P>SOLUTION: This method constructs the underground structure by using the plurality of tunnels, and includes a process of constructing a preceding tunnel 1A by arranging a jacking box body 10 in the rear of a jacking machine 2 together with excavation of the natural ground by the jacking machine 2 and a process of constructing a succeeding tunnel 1B by being juxtaposed with the preceding tunnel 1A by arranging the jacking box body 10 in the rear of the jacking machine 2 together with the excavation of the natural ground by the jacking machine 2. An outbreak part 30 is formed in a corner part on the succeeding tunnel 1B side of the preceding tunnel 1A in the process of constructing the preceding tunnel 1A, and the corner part of the succeeding tunnel 1B is arranged in the outbreak part 30 in the process of constructing the succeeding tunnel 1B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for constructing an underground structure by a propulsion method.

As a method of constructing underground structures such as large cross-section tunnels, a small cross-section shield machine configures the outer shell by arranging a plurality of small cross-section shield tunnels arranged along the outside of the large cross-section tunnel in the ground. In addition, there is an outer shell leading shield method in which the inside of the outer shell portion is excavated without using the shield method to construct a large section tunnel.
And about this outer shell part precedent type shield construction method, patent document 1 equips the side edge part of a small section shield machine with a ground improvement cutter, and at the same time it excavates a small section shield tunnel, a small section shield tunnel A method of excavating the ground at the joint portion between each other to improve the ground is disclosed. Thereby, the water stop at the time of integration of an outer shell part is secured.

  However, in such a shield type leading shield method, due to the shield structure, a plurality of small section shield tunnels are arranged side by side with clearance at the tail section, so there is an inevitable gap between the small section shield tunnels. There was an inconvenience of creating an area.

  That is, in the state where such a gap region is formed, the outer shell portion of the large-section tunnel does not have an integral structure. For this reason, a complicated and time-consuming work for integrating the outer shell portion of the large section tunnel has been forced by excavating the gap region, assembling the reinforcing bars, and placing concrete.

Therefore, as shown in Patent Document 2, the present applicant has developed and implemented a method for constructing a large-section tunnel using a plurality of small-section tunnels arranged side by side. In this large cross-section tunnel construction method, multiple small cross-section tunnels were placed side by side, and then each small cross-section tunnel was left while forming a large space by removing unnecessary lining of each small cross-section tunnel. A large section tunnel is constructed by forming an outer shell using lining.
Construction of each small section tunnel is carried out so as to contact each adjacent small section tunnel by the propulsion method, and the box of the tunnel constructed in advance (hereinafter sometimes simply referred to as “preceding tunnel”) The guide groove formed on the side surface is dug while fitting the protrusions formed on the side surface of the box of the tunnel to be constructed following (hereinafter sometimes referred to simply as the “backward tunnel”). It is.
JP-A-9-242474 ([0004]-[0012], FIGS. 1 to 4) JP 2001-214699 A ([0015]-[0038], FIGS. 1-3)

  However, in the above underground structure, there is no water stopping function between the propelling boxes, and in order to ensure the water stopping property of the underground structure after completion, the arrangement of a water stopping plate on the joint part or a chemical solution is separately provided. It was necessary to construct a water stop structure by injection or the like, and this work required time and the construction period was long.

  The present invention has been made to solve the above-described problems, and easily and quickly builds an underground structure excellent in water-stopping constructed by using a plurality of tunnels arranged side by side. It is an object to propose a construction method for underground structures that makes this possible.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a method for constructing an underground structure using a plurality of tunnels, and excavating a natural ground by a propulsion device and behind the propulsion device. A process of constructing a preceding tunnel by arranging a box, and excavating a natural mountain with a propulsion unit, and arranging a box behind the propulsion unit to construct a subsequent tunnel in parallel with the preceding tunnel A step of constructing the preceding tunnel in the step of constructing a surplus portion on the side of the succeeding tunnel of the preceding tunnel, and in the step of constructing the succeeding tunnel, a part of the succeeding tunnel is formed. , It is characterized in that it is arranged in the over-digging part.

  The invention according to claim 2 is the construction method of the underground structure according to claim 1, wherein the tunnel has a rectangular cross section, and the digging portion is positioned behind the preceding tunnel. It is formed in a corner portion on the tunnel side, and the corner portion of the succeeding tunnel is arranged in the overexcavated portion.

  According to the construction method of such an underground structure, in order to perform the excavation excavation of the joint portion with the adjacent tunnel in parallel with the construction of the preceding tunnel, if the water stop treatment is performed using this extra excavation portion, It is possible to construct an underground structure with excellent water blocking properties without performing a separate waterproofing work as in the conventional construction method for underground structures. In other words, the trailing tunnel is constructed so that a part (corner portion) of the trailing tunnel is disposed in the overexcavation portion. In this state, the water stop area is formed, and the water stop of the joint portion is completed. Therefore, it is possible to omit troublesome operations such as the arrangement of the water stop plate and the injection of the chemical solution that have been conventionally required.

  The invention according to claim 3 is the construction method of the groundwater structure according to claim 1 or claim 2, wherein in the step of constructing the preceding tunnel, the surplus portion is filled with a filler. It is characterized by forming a waterstop.

  According to the construction method of such an underground structure, in order to form a waterstop for the overexcavated portion along with the advancement of the preceding tunnel, the collapse of the ground in the overexcavated portion is prevented and when filling is performed after the completion of the tunnel propulsion. Compared to this, the construction period can be shortened.

  The invention according to claim 4 is the construction method of the underground structure according to claim 1 or claim 2, wherein after the step of constructing the subsequent tunnel, a filler is added to the surplus portion. It is characterized by including the process of filling and forming a water stop body.

  According to such a construction method of an underground structure, it is possible to smoothly carry out the subsequent tunnel, which is preferable.

  The invention according to claim 5 is the construction method of the underground structure according to claim 4, wherein, in the step of constructing the preceding tunnel, a temporary box is disposed in the overexcavated portion. It is said.

  According to such a construction method of an underground structure, a temporary box is disposed in the overexcavated portion, thereby preventing the natural ground from collapsing during the promotion of the trailing tunnel. For this reason, the shape of the surplus digging portion is maintained, and excavation of a portion corresponding to the surplus digging portion can be omitted when the subsequent tunnel is propelled.

  Moreover, invention of Claim 6 is the construction method of the underground structure of any one of Claim 1 thru | or 5, Comprising: The said propulsion machine is in the position corresponding to the said surplus digging part. A detachable sub cutter is provided, and excavation of the excessive excavation part is performed by changing the sub cutter.

  According to the construction method of the underground structure, it is possible to set the presence or absence of excavation of the overexcavation part by appropriately changing the subcutter of the propulsion unit, thereby eliminating waste such as excavation of the excessive excavation part in an unnecessary place. Is possible. Even when the position or the excavation shape of the extra excavation portion is changed for each tunnel, the same propulsion device can be used by changing the sub cutter, so that the equipment cost can be greatly reduced.

  With the underground structure building method of the present invention, it is possible to easily and quickly build an underground structure that is built using a plurality of tunnels arranged side by side and has excellent water blocking properties.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.
Here, FIG. 1 is a cross-sectional view showing an underground structure according to the present embodiment. Moreover, FIG. 2 is a perspective view which shows the outline of the propulsion apparatus used for construction | assembly of the underground structure based on this embodiment, Comprising: (a) is the state which installed the corner cutter part, (b) is a corner cutter part. It shows the state where is removed. 3 (a) to 3 (c) are plan views showing a situation where the corner cutter portion of the propulsion device shown in FIG. 2 is changed, and FIG. 3 (d) is a sectional view thereof. Furthermore, Fig.4 (a)-(f) is a cross-sectional view which shows each construction step of the construction method of the underground structure which concerns on this embodiment.

  In this embodiment, as shown in FIG. 1, a large section tunnel (underground structure) T is constructed by connecting a plurality of (in this embodiment, six) tunnels 1, 1,. How to do will be described.

The large-section tunnel T according to the present embodiment is formed by connecting six tunnels 1, 3,... In two stages in parallel, and connecting each tunnel 1 with a propulsion device 2 (see FIG. 2). ) Along with the excavation of the natural ground and the step of constructing the preceding tunnel (tunnel 1) by placing the propulsion box (housing) 10 behind the propulsion unit 2, and the excavator 2 with the excavation of the natural ground with the propulsion unit 2 It arrange | positions in parallel with a preceding tunnel by arrange | positioning the propelling box 10 in the back, and is constructed | assembled by the process of constructing | reconstructing a subsequent tunnel (tunnel 1).
Then, in the step of constructing the preceding tunnel, an overburden portion 30 is formed in the corner portion on the side of the succeeding tunnel of the preceding tunnel, and in the step of constructing the succeeding tunnel, the corner portion of the succeeding tunnel is replaced with this surplus portion. Arranged in the digging portion 30.

  Furthermore, a water blocking body 31 is formed in the surplus digging portion 30 formed at the junction between adjacent tunnels 1, and the penetration of groundwater into the large-section tunnel T from the gap s between the junctions between the tunnels 1. Is preventing.

  Each of the tunnels 1, 1,... Is a main jack or intermediate jack that pushes the propulsion box (box) 10 into the excavation hole excavated by the propulsion unit 2 from behind the propulsion unit 2 (see FIG. 2) excavating the natural ground. It is constructed by placing the propelling box 10 in the ground with a jack (not shown).

  As shown in FIG. 2A, the propulsion device 2 is composed of a propulsion device main body 20 and corner cutter portions 21, 21,... Detachably installed on the propulsion device main body 20. The main cutter 22 and the corner cutters (sub-cutters) 23, 23,... (Hereinafter referred to as “main cutter 22” and “corner cutter 23” are not distinguished on the front surfaces of the propulsion device body 20 and the corner cutter unit 21, respectively. Are simply referred to as “cutter heads 22, 23”).

  Here, the form of the cutter heads 22 and 23 is not limited, and can be appropriately selected from known forms such as a face plate type and a spoke type according to the condition of the natural ground. is there. Further, the method of the cutter heads 22 and 23 is not limited, and either a swing type or a rotary type may be used. Furthermore, in this embodiment, circular cutter heads 22 and 23 are used. However, for example, elliptical or rectangular shapes may be used, and the shapes of the cutter heads 22 and 23 are not limited.

The corner cutter portions 21, 21,... Of the propulsion device 2 according to the present embodiment are positions around the propulsion device main body 20 and corresponding to the four corners of the propulsion box 10 as shown in FIG. As shown in FIG. 2B, the propulsion unit main body 20 is detachably installed.
In the present embodiment, as the excavator 2, an excavating section (the excavator main body 20) having a substantially square shape is used. However, the shape of the excavator 2 is not limited, and may be, for example, circular or elliptical. What is necessary is just to set suitably according to the completed cross-sectional shape of the large cross-section tunnel T, such as a rectangle, a trapezoid. Further, with respect to the corner cutter mounting portion 20a of the excavator 2, a normal excavator (without excavating the surplus digging portion 30) is provided by installing a cover without installing the corner cutter portion 21 (corner cutter 23). 2 can also be used.

  As the corner cutter portions 21, 21,..., Large corner cutters 23a and small corner cutters 23b having different excavation diameters (corner cutters 23) are used as appropriate according to the construction stage ( (Refer FIG.4 (a)-(f)). That is, as shown in FIG. 3A, when all the corner cutters 23 are large corner cutters 23a and 23a according to the construction stage, or as shown in FIG. When different cutters 23a and small corner cutters 23b are used, or as shown in FIG. 3 (c), small corner cutters 23b may be used for all corner cutters 23 and 23. Here, as shown in FIG. 3 (d), the attachment portion 21a of each corner cutter portion 21 is formed in the same shape as the corner cutter attachment portion 20a of the propulsion device body 20, and the shape of the corner cutter 23 changes. Even so, since the shape of the attachment portion 21a is the same, attachment to the propulsion device main body 20 is possible. That is, since the attachment portions 21a of the small corner cutter 23b and the large corner cutter 23a are formed in accordance with the corner cutter attachment portion 20a of the propulsion device main body 20, they can be exchanged. In this embodiment, the shapes of the corner cutter mounting portion 20a and the mounting portion 21a are formed in an arc shape. However, the shapes of the corner cutter mounting portion 20a and the mounting portion 21a are not limited to the arc shape, and are appropriately set. Needless to say, you can do it.

  As shown in FIG. 1, the propulsion box 10 includes an outer shell 11 formed of a steel plate in a rectangular tube shape, and a reinforcing member 12 made of steel on the inner surface of the outer shell 11 along the outer shell 11 in the tunnel axial direction and transverse direction. It is comprised by arrange | positioning in a direction. A gap for forming a guide groove J <b> 1 to be described later is formed at a predetermined portion of the outer shell 11. In addition, the material and shape which comprise the propelling box 10 are not limited, What is necessary is just to set suitably according to a condition.

  Further, the propulsion box 10 has both or one of the guide groove J1 and the projecting member J2 attached in the vicinity of the corner portion of the outer shell 11. The positions and the number of the guide grooves J1 and the projecting members J2 are appropriately set according to the arrangement of the tunnel 1.

  The guide groove J1 according to the present embodiment is formed into a groove having a T-shaped cross section (so-called T groove) by combining steel materials. Needless to say, the shape of the guide groove J1 may be appropriately formed according to the shape of the protruding member J2, and the shape is not limited.

  The projecting member J <b> 2 is disposed at a position corresponding to the guide groove J <b> 1 of the adjacent propelling box 10 on the outer peripheral surface of the outer shell 11, and projects to the outside of the outer shell 11. In the present embodiment, the projecting member J <b> 2 is configured by welding and joining a rail to the outer peripheral surface of the outer shell 11.

  The rail constituting the projecting member J2 is made of hot stamped steel, and includes a flange fixed to the outer peripheral surface of the outer shell 11, a web rising from the flange, and a head formed at the projecting end portion of the web. ing. Since the width (thickness) of the rail web is smaller than the width of the narrow portion of the guide groove J1, and the cross-sectional area of the head is smaller than the cross-sectional area of the wide portion of the guide groove J1. The rail enters the inside of the guide groove J1 with a clearance that can move vertically and horizontally. That is, the protruding member J2 is coupled to the guide groove J1 in a loosely fitted state. Further, the head of the projecting member J2 is formed to have a width that is larger than the width of the narrow portion of the guide groove J1. In this way, the protruding member J2 is prevented from coming out of the guide groove J1, so that the adjacent propelling boxes 10 and 10 can be prevented from separating more than necessary. Hereinafter, the joint composed of the guide groove J1 and the protruding member J2 may be referred to as a “joint portion J”.

  Here, in the present embodiment, the propulsion box 10 having a substantially square cross section is used, but the cross section of the propulsion box 10 is not limited, and may be, for example, a rectangle, a circle, or an ellipse. What is necessary is just to set suitably according to the completion | finish cross-sectional shape of the underground structure to construct, or a natural ground condition, such as using a shape and other polygonal shape.

  Next, the construction method of the large-section tunnel T according to the present embodiment will be described in detail with reference to the drawings.

  In this embodiment, as shown in FIGS. 4A to 4F, the construction of a plurality of tunnels 1, 1,... The lower left tunnel 1c, the upper right tunnel 1d, the upper middle tunnel 1e, and the upper left tunnel 1f are constructed in this order. Needless to say, the construction order of the tunnels 1, 1,... Is not limited, and may be set as appropriate according to the situation.

  In contrast to a plan in which six tunnels 1, 1,... Are arranged in two stages, three tunnels 1a on the lower right side are first constructed as shown in FIG. At this time, the corners on the tunnels 1b, 1d, and 1e side of the propulsion unit 2, that is, the lower left side, the upper right side, and the upper left side of the tunnel 1a (the preceding tunnel 1A) adjacent to the area where the subsequent tunnel 1B is constructed. The corner cutters 21, 21, 21 corresponding to the corners employ large corner cutters 23a, and the corners of the tunnels 1b, 1d, 1e are included in the corners 21a, 21 and 21, respectively. Shall be formed. The corner cutter 21 corresponding to the other corner, that is, the lower right corner serving as the corner of the large section tunnel T, employs a small corner cutter 23b. Excavation according to the shape.

  Further, the placement of the propulsion box 10 in the excavation hole excavated by the propulsion device 2 is performed by applying a pressing force (propulsion force) to the propulsion box 10 with a main push jack. The arrangement of the propelling box 10 in the ground is not limited to the method using the original push jack, and may be appropriately selected from known means such as using an intermediate push jack. Alternatively, a method may be employed in which the propulsion box 10 is pushed from the wellhead by a main push jack and the middle propulsion jack of the propulsion device 2 is contracted and drawn to the propulsion box 10.

  The surplus digging portion 30 formed together with the construction of the lower right tunnel 1a is filled with a filler to form a waterstop 31 (see FIG. 4B). The waterstop 31 is formed in parallel to the excavation of the natural ground by the propulsion device 2 and the placement of the propelling box 10 in parallel with the injection of the sliding member (also a backfill material) of the propulsion box 10. In this embodiment, it is assumed that the same material is used for the lubricant and the filler of the surplus digging portion 30, and the injection (filling) operation is performed simultaneously.

  As the filler, for example, by reacting water glass with a calcium hydroxide suspension or a suspension containing calcium hydroxide and slag, the gel time is within 60 seconds, and the initial strength is developed early, It is preferable to use one having a property that the strength expression is within 30%. According to this filler, an unnecessarily strong strength is not exhibited, and leakage into the natural space is not caused. In other words, an excellent water stop function is exhibited at the joint between adjacent propelling boxes 10 and the material cost required for filling can be minimized because the filler does not leak out. During the excavation, there is no problem that the excavation becomes impossible due to the strength of the waterstop 31 after curing.

Moreover, according to the said filler, since the adhesion strength with steel materials is low, it does not adhere to the propelling box 10 and also functions as a lubricant.
Needless to say, the material of the filler is not limited to the above as long as it exhibits water-stopping properties.

  When the construction of the lower right tunnel 1a (preceding tunnel 1A) is completed or the predetermined length of construction has progressed, as shown in FIG. 4 (b), the tunnel 1b (following in the lower middle) is located next to the lower right tunnel 1a. Construction of tunnel 1B) is started. At this time, large corner cutters 23a are provided in the upper and lower corner cutter parts 21 and 21 of the propulsion unit 2 that are not adjacent to the preceding tunnel 1A (tunnel 1a) and are located in the region where the subsequent tunnel 1B is constructed. , 23a are installed to excavate the surplus portion 30. On the other hand, small corner cutters 23b and 23b are installed in the upper and lower corner cutter parts 21 and 21 adjacent to the preceding tunnel 1A to excavate natural ground. That is, in the construction of the lower center tunnel 1b, the corner on the left side tunnel 1c side of the lower left side forms a dug 30 that includes the corner of the tunnel 1c, and the lower right side tunnel on the right side. For the 1a side, the propulsion box 10 is placed while excavating a part of the waterstop 31 constructed together with the construction of the tunnel 1a.

  Further, the arrangement of the propulsion box 10 in the trailing tunnel 1B (the lower center tunnel 1b) is such that the protruding member J2 formed on the propulsion box 10 in the excavation hole excavated by the propulsion unit 2 (see FIG. 1). Is inserted into the guide groove J1 (see FIG. 1) of the propulsion box 10 of the preceding tunnel 1A (the lower right tunnel 1a). It should be noted that the joint portions J between the preceding tunnel 1A and the succeeding tunnel 1B are disposed at two locations above and below the installation surface of the preceding tunnel 1A and the succeeding tunnel 1B.

  The method for press-fitting the propelling box 10 into the excavation hole is the same as the method described above, and a detailed description thereof will be omitted. Moreover, since the filling method etc. of the filler to the surplus digging part 30 are the same as the method shown above, detailed description is abbreviate | omitted.

  When the construction of the lower center tunnel 1b (preceding tunnel 1A) is completed or the predetermined length of construction has progressed, as shown in FIG. 4 (c), in the same manner as described above, Construction of tunnel 1c (following tunnel 1B) is started. Note that the joint portions J between the preceding tunnel 1A and the succeeding tunnel 1B are disposed at two locations above and below the facing surface of the preceding tunnel 1A and the succeeding tunnel 1B. At this time, a large corner cutter 23a is installed in the corner cutter 21 on the left side of the propulsion unit 2 that is not adjacent to the preceding tunnel 1A (tunnel 1b) and adjacent to the area where the trailing tunnel 1B is constructed. The excavation part 30 is excavated. Also, small corner cutters 23b and 23b are installed in the upper and lower right corner cutter portions 21 adjacent to the preceding tunnel 1A, and a part of the water stop body 31 formed by the construction of the lower center tunnel 1b is excavated. While promoting. The lower left corner, which is the corner of the large section tunnel T, excavates an excavation hole corresponding to the shape of the propulsion box 10 with a small corner cutter 23b.

  Regarding the construction of the other tunnel 1c on the left side of the lower stage, the excavation method by the propulsion device 2, the placement method of the propulsion box 10 in the ground, the construction method of the waterstop 31 and the like are the same as described above. Description is omitted.

  Then, when the construction of the lower three tunnels 1a, 1b, 1c is completed or the predetermined extension construction has progressed, as shown in FIG. 4D, the upper right tunnel 1d is adjacent to the upper right tunnel 1a. Construction of (following tunnel 1B) is started. At this time, the protruding member J2 formed on the lower surface of the propulsion box 10 of the trailing tunnel 1B was inserted into the guide groove J1 formed on the upper surface of the propulsion box 10 of the preceding tunnel 1A (the lower right tunnel 1a). In the state, the construction of the trailing tunnel 1B is advanced. Further, the lower corner portion of the trailing tunnel 1B is performed while excavating a part of the waterstop 31 constructed together with the construction of the preceding tunnel 1A (the lower right tunnel 1a) by the corner cutter 23b.

  The propulsion unit 2 at the time of construction of the trailing tunnel 1B (tunnel 1d) is not adjacent to the preceding tunnel 1A, and the large corner cutter 21 is located on the left corner cutter 21 adjacent to the area where the trailing tunnel 1B is constructed. 23a is installed to excavate the surplus digging portion 30. Small corner cutters 23b, 23b, and 23b are installed at the right and left corner cutters 21 adjacent to the other preceding tunnel 1A (tunnels 1a and 1b) and the corners of the large section tunnel T. Then, excavation is performed according to the shape of the propelling box 10.

  In addition, since the excavation method by the propulsion device 2, construction method of the propulsion box 10 in the ground, construction method of the waterstop body 31 and the like regarding the construction of the other upper right tunnel 1d are the same as described above, detailed description will be given. Is omitted.

  When the construction of the upper right tunnel 1d is completed or the predetermined length of construction has progressed, as shown in FIG. 4 (e), the upper right tunnel 1d (advanced tunnel 1A) is adjacent to the lower middle tunnel 1b (advanced). Construction of the upper tunnel 1e (following tunnel 1B) is started on the upper side of the tunnel 1A). At this time, the projecting member J2 formed on the side surface and the lower surface of the propulsion box 10 of the following tunnel 1B is formed on the side surface of the propulsion box 10 of the upper right tunnel 1d (preceding tunnel 1A) on the side of the subsequent tunnel 1B. In the state where the guide tunnel J1 is inserted into the guide groove J1 formed on the upper surface of the propulsion box 10 of the guide groove J1 and the lower center tunnel 1b (preceding tunnel 1A), the construction of the trailing tunnel 1B is advanced. In addition, the lower corner of the trailing tunnel 1B includes three waterstops 31 constructed together with the construction of the preceding tunnel 1A (the lower right tunnel 1a, the lower middle tunnel 1b, and the upper right tunnel 1d). A part is excavated by the small corner cutter 23b.

  The propulsion unit 2 at the time of construction of the trailing tunnel 1B installs a large corner cutter 23a in the corner cutter portion 21 on the left side that is not adjacent to the preceding tunnel 1A and adjacent to the area where the trailing tunnel 1B is constructed. The excavation part 30 is excavated. Propulsion placed in the construction method of the propulsion unit 2 by installing small corner cutters 23b and 23b in the left and right and upper right corner cutters 21 adjacent to the other preceding tunnel 1A (tunnels 1a, 1b, 1c and 1d). Excavation according to the shape of the box 10 is performed.

  In addition, since the excavation method by the propulsion device 2 regarding the construction of the tunnel 1e on the upper right side, the arrangement method of the propulsion box 10 in the ground, the construction method of the waterstop 31 and the like are the same as described above, detailed description will be given. Is omitted.

  Further, when the construction of the upper center tunnel 1e is completed or the predetermined length of construction has progressed, as shown in FIG. 4 (f), next to the upper center tunnel 1e and above the lower left tunnel 1c, Construction of the upper left tunnel 1f (following tunnel 1B) is started. At this time, the protruding member J2 formed on the side surface and the lower surface of the propulsion box 10 of the trailing tunnel 1B is formed on the side surface of the trailing tunnel 1B side of the propulsion box 10 of the upper tunnel 1e (preceding tunnel 1A). Construction of the trailing tunnel 1B is advanced in a state where the guide groove J1 is inserted into the guide groove J1 formed on the upper surface of the propulsion box 10 of the lower left tunnel 1c (preceding tunnel 1A). In addition, the lower corner of the following tunnel 1B has three stops constructed along with the construction of the preceding tunnel 1A (the lower center tunnel 1b, the lower left tunnel 1c, and the upper center tunnel 1e). This is performed while excavating a part of the water body 31.

  The propulsion unit 2 at the time of construction of the trailing tunnel 1B is provided with small corner cutters 23b, 23b,... For all corner cutter units 21, 21,. Excavation according to the shape of the.

  In addition, since the excavation method by the propulsion device 2, the arrangement method of the propulsion box 10 in the ground, the construction method of the waterstop body 31, and the like regarding the construction of the other upper right tunnel 1f are the same as described above, a detailed description will be given. Is omitted.

  When the construction of the tunnels 1a to 1f is completed, an unnecessary portion of the propulsion box 10 of the tunnels 1a to 1f is removed to form a large space according to the cross-sectional shape of the large-section tunnel T as shown in FIG. . At this time, a substantially semicircular water stop 31 is formed on the natural ground side of the junction of each of the tunnels 1a to 1f to prevent the penetration of groundwater from the gap s.

  And, using the propelling boxes 10, 10,... Of the tunnels 1a to 1f left along the boundary with the natural ground (that is, the outer edge of the large section tunnel T), When the side walls TC and TC are formed, a large-section tunnel T is formed. The top plate TA, the bottom plate TB, and the side walls TC and TC may be formed after removing all unnecessary portions of the propelling box 10, or while removing some of the unnecessary portions of the tunnels 1a to 1f, The top plate TA, the bottom plate TB, and the side walls TC and TC of the large section tunnel T may be constructed.

In addition, the construction method of the still water body 31 is not limited to the above-described method. For example, in the process of constructing the preceding tunnel 1A, by placing a temporary box in the overexcavated portion 30, the collapse of the natural ground is prevented. After the step of preventing and constructing the trailing tunnel, a method of forming the waterstop 31 by filling the surplus portion 30 with a filler may be applied.
Moreover, during the tunnel 1, 1, ... propulsion construction, muddy water or bentonite mud fluid, etc., injected into the overexcavated portion 30 is injected as a lubricant to prevent the collapse of the natural ground, and the propulsion box is propelled. May be constructed by replacing the muddy water and the filler.

  As described above, according to the tunnel construction method of the present invention, the extra digging portion 30 is formed in advance, and the extra digging portion 30 is filled with the filler to stop water at the junction between adjacent tunnels 1. The water stop work is completed without the need for complicated work such as installing a water stop plate or injecting chemicals. Therefore, the construction period required for constructing the large-section tunnel T can be significantly shortened, and the cost can be significantly reduced by shortening the construction period and omitting complicated water stop work.

  And since the still water body 31 is formed along the junction part of adjacent tunnels 1, the penetration | invasion of the groundwater from the clearance gap s is completely prevented, and the large cross-section tunnel T excellent in the water stop property is constructed | assembled. Making it possible.

  Further, with respect to the corner cutter unit 21 of the propulsion device 2, in order to perform the construction by appropriately changing the large corner cutter 23a and the small corner cutter 23b according to the construction stage, excavation and stopping according to the propulsion box 10 are performed. It is possible to perform excavation according to the construction of the water body 31, which is preferable.

  Further, in order to construct the succeeding tunnel 1B while inserting the protruding member J2 of the succeeding tunnel 1B into the guide groove J1 of the preceding tunnel 1A, a large-section tunnel T comprising a plurality of tunnels 1, 1,. It is possible to build.

Further, if the protruding member J2 is formed so as to be loosely fitted inside the guide groove J1, the leading tunnel 1A is meandering or twisted, or the propulsion device 2 of the trailing tunnel 1B is rolled or pitched. Even if such a situation occurs, these effects are absorbed by the joint portion J of both tunnels 1A and 1B, so that the construction can be performed reliably.
In other words, when the propulsion box 10 serving as the trailing tunnel 1B is pushed out along the preceding tunnel 1A, the protruding member J2 of the propulsion box 10 is inserted into the guide groove J1 of the propulsion box 10 from the tunnel axis direction. However, since this projecting member J2 enters the guide groove J1 in a loosely fitted state, rolling or the like occurs in the propulsion device 2 of the subsequent tunnel 1B even if the preceding tunnel 1A is meandering or the like. Even so, there is no inconvenience that the guide groove J1 and the protruding member J2 immediately compete with each other, and as a result, the propulsion box 10 of the trailing tunnel 1B can be pushed out smoothly.

  Further, as shown in FIG. 1, the joint portion J is coupled in a loosely fitted state so as to be able to cope with meandering of the tunnel 1 and the like, while the head portion of the rail (that is, the protruding end portion of the protruding member J2). ) Is formed in a width dimension larger than the width of the narrow portion of the guide groove J1 (opening width of the guide groove J1), so that the adjacent propelling boxes 10 and 10 are not separated more than necessary. As a result, it is possible to construct a large section tunnel T with high dimensional accuracy.

  In addition, according to the tunnel construction method and the following tunnel construction method of the present embodiment, when constructing the large-section tunnel T in a place where the earth covering is difficult to be formed or in a ground with low strength, Since the cross-section tunnel is divided into a plurality of tunnels 1, 1,..., The construction can be performed safely.

Next, another preferred embodiment according to the present invention will be described.
Here, FIG. 5 is a figure which shows the construction method of the underground structure of other embodiment, Comprising: (a) is whole sectional drawing, (b) is a fragmentary sectional view.

In another embodiment, as shown in FIG. 5 (a), a plurality of tunnels 1, 1,. It forms the outer shell (lining) of the underground structure T ′.
Each tunnel 1 includes a step of constructing a preceding tunnel (tunnel 1) by excavating a natural ground with a propulsion device 2 (see FIG. 2) and placing a propulsion box (box) 10 ′ behind the propulsion device 2. In addition to excavation of natural ground by the propulsion unit 2, the propulsion box 10 'is arranged behind the propulsion unit 2 to be arranged in parallel with the preceding tunnel to construct the subsequent tunnel (tunnel 1) ( (Refer FIG.5 (b)).
Then, in the step of constructing the preceding tunnel, an overburden portion 30 is formed in the corner portion on the side of the succeeding tunnel of the preceding tunnel, and in the step of constructing the succeeding tunnel, the corner portion of the succeeding tunnel is replaced with this surplus portion. Arranged in the digging portion 30.

  Furthermore, a waterstop 31 is formed in the surplus digging portion 30 formed at the junction between adjacent tunnels 1, and the penetration of groundwater into the large cross-section tunnel T from the gap between the junctions between the tunnels 1. It is preventing.

  Each tunnel 1, 1,... Is a main push jack that pushes the propulsion box (box) 10 ′ into the excavation hole excavated by the propulsion unit 2 from behind the propulsion unit 2 (see FIG. 2) excavating the natural ground. It is constructed by placing the propelling box 10 in the ground with an intermediate jack (not shown).

As shown in FIG. 2A, the propulsion device 2 is composed of a propulsion device main body 20 and corner cutter portions 21, 21,... Detachably installed on the propulsion device main body 20. And as shown in FIG.5 (b), as for the propulsion-machine main body 20, the width | variety of an upper end is wider than the width | variety of a lower end, and the cross section of the excavation hole drilled by the said excavator 2 is formed in trapezoid shape. It is comprised so that.
Since the configuration of the other excavator 2 is the same as that described above, detailed description thereof is omitted.

As shown in FIG. 5 (a), the propulsion box 10 'has a trapezoidal cross section and is arranged in parallel so that the long side surface of the trapezoid is on the outer peripheral side of the large cross section tunnel T'. By doing so, it is configured to exhibit a substantially circular shape. In addition, the material, detailed shape, etc. which comprise propulsion box 10 'are not limited, It determines suitably according to the condition of a field, the completed section of an underground structure, etc.
Each propelling box 10 ′ is formed with a joint portion (not shown) in order to prevent the tunnels 1 constructed adjacent to each other from approaching or separating from each other. Here, since the details of the joint portion are the same as the contents shown above, detailed description is omitted.

  Next, a method for constructing the large-section tunnel T ′ will be described in detail with reference to the drawings.

  As shown in FIG. 5, the large-section tunnel T ′ is constructed by sequentially constructing the next tunnel 1 (following tunnel) adjacent to the constructed tunnel 1 (preceding tunnel). Needless to say, the construction order of the tunnels 1, 1,... Is not limited, and may be set as appropriate according to the situation.

  First, a predetermined tunnel (preceding tunnel N) is constructed at a position corresponding to the planned outer shell of the underground structure. At this time, the corner cutters corresponding to the four corners of the propulsion unit 2, that is, the upper, lower, left and right corners of the preceding tunnel N adjacent to the area where the trailing tunnel N + 1 and the trailing tunnel N-1 are constructed. 21, 21,... Employ a large corner cutter (subcutter) 23 a, and form a dug 30 having a shape including the corners of the following tunnels N + 1 and N−1 at each corner. (See FIG. 5B). In the present embodiment, the overexcavated portion 30 is formed at the four corners of the preceding tunnel N. However, the overexcavated portion 30 may be formed only at the corner corresponding to the succeeding tunnel. What is necessary is just to set suitably according to the completion cross section of this, a construction plan, etc.

  Details about the construction of the other preceding tunnel N are the same as the contents described in the above embodiment, and thus detailed description thereof is omitted.

  When the construction of the preceding tunnel N is completed or the predetermined length of construction has progressed, the construction of the subsequent tunnel N + 1 is started next to the preceding tunnel N as shown in FIG. At this time, large corner cutters 23a and 23a are installed in the upper and lower corner cutter units 21 and 21 on the right side of the propulsion unit 2 that are not adjacent to the preceding tunnel N and are in the region where the subsequent tunnel N + 1 is constructed. The excavation part 30 is excavated. On the other hand, small corner cutters (sub-cutters) 23b and 23b are installed in the left and upper corner cutter parts 21 and 21 adjacent to the preceding tunnel N to excavate natural ground. That is, in the construction of the succeeding tunnel N + 1, the corner portion on the opposite side to the preceding tunnel N forms an overexcavated portion 30 including the corner portion of the adjacent tunnel, and the preceding tunnel N side has a leading portion. This is done by arranging the propelling box 10 'while excavating a part of the waterstop 31 constructed together with the construction of the tunnel N.

  Further, the arrangement of the propulsion box 10 ′ of the trailing tunnel N + 1 is arranged in the excavation hole excavated by the propulsion machine 2 in the joint portion (not shown) of the propulsion box 10 ′ and the propulsion box 10 of the preceding tunnel N. It is performed with the joint part of '(not shown) engaged.

  Further, the method for press-fitting the propelling box 10 'into the excavation hole is the same as the method described above, and a detailed description thereof will be omitted. Moreover, since the filling method etc. of the filler to the surplus digging part 30 are the same as the method shown above, detailed description is abbreviate | omitted.

  By the same method, the tunnels 1 are arranged side by side at any time to construct the subsequent tunnel N-1. Then, the outer shell of the large-section tunnel T ′ is constructed by placing concrete in each tunnel 1. In addition, the placement of concrete into each tunnel 1 may be performed at any time for each tunnel 1, or after removing the skin plate between adjacent tunnels 1 and connecting the tunnels 1, A monolithic outer shell may be formed by placing concrete on the wall.

  In another embodiment, a trapezoidal propelling box 10 'is arranged in parallel to form a circular structure. However, the present invention is not limited to this. What is necessary is just to form in the shape according to the situation suitably, such as formation of a shape or an arch-like structure. Needless to say, the shape of the propelling box 10 'is not limited to a trapezoid.

  Since the effects and the like by the construction method of the underground structure according to the other embodiment are the same as the contents shown in the above embodiment, detailed description thereof is omitted.

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, in the above embodiment, the construction method of the underground structure of the present invention is applied to the construction of the large section tunnel. However, the underground structure constructed by the construction method of the underground structure of the present invention is large. It is not limited to a cross-sectional tunnel. Needless to say, the purpose of use of the large section tunnel is not limited.

  In addition, the construction direction of the preceding tunnel and the following tunnel is not limited, and after the construction of the preceding tunnel, the construction of the succeeding tunnel is performed by turning the propulsion unit in the opposite direction (with a U-turn) at the reaching shaft. The direction of the starting shaft from the arrival shaft, that is, the method of constructing the construction direction of the preceding and succeeding tunnels in the opposite direction, the method of constructing the preceding tunnel and the following tunnel in the same direction, etc. may be set as appropriate. .

  Moreover, in the said embodiment, when constructing the subsequent tunnel, it was assumed that the construction was performed while excavating the waterstop formed with the construction of the preceding tunnel. When it is arranged and the space of the excessive excavation part is maintained, the corner part need not be excavated at the time of constructing the subsequent tunnel. That is, at the time of construction of the trailing tunnel, excavation is performed with the corner cutter portion corresponding to the corner portion of the propulsion unit removed, and the propulsion box may be arranged while removing the temporary box.

Moreover, although the said embodiment demonstrated the case where two types, a large corner cutter and a small corner cutter, were used as a corner cutter (sub cutter), the kind of corner cutter is not limited to two types, and the construction situation It may be increased according to the excavation cross-sectional shape and the like.
Further, the arrangement of the corner cutters is not limited to the above arrangement, and it goes without saying that the corner cutters may be appropriately changed according to the construction order of each tunnel.

  In addition, the method of holding the ground in the overexcavated portion is not limited to the above-described method, and may be appropriately selected from known means.

  Moreover, the member which comprises a propelling box is not limited, For example, it may be comprised by the member made from steel, the member made from spheroidal graphite cast iron, Furthermore, it is a member made from reinforced concrete. It may be configured.

Moreover, although it was set as the structure attached to the side surface of a propulsion box by welding, for example, the flange part of a rail may be fastened to the side of a propulsion box via a bolt and a nut. It is not limited.
Moreover, in the said embodiment, although the protrusion member shall be formed with a rail, you may form combining a steel plate, for example, The formation method of a protrusion member is not limited. Similarly, in the embodiment, the guide groove is formed by combining the shape steels, but it goes without saying that the method of forming the guide groove is not limited.

It is a cross-sectional view showing an underground structure according to this embodiment. It is a perspective view which shows the outline of the propulsion machine used for construction of an underground structure concerning this embodiment, and (a) shows the state where the corner cutter part was installed, and (b) shows the state where the corner cutter part was removed. ing. (A)-(c) is a top view which shows the condition which changed the corner cutter part of the propulsion machine shown in FIG. 2, (d) is the same sectional drawing. (A)-(f) is a cross-sectional view which shows each construction step of the construction method of the underground structure which concerns on this embodiment. It is a figure which shows the construction method of the underground structure of other embodiment, Comprising: (a) is whole sectional drawing, (b) is a fragmentary sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tunnel 1A Leading tunnel 1B Trailing tunnel 10 Propulsion box 2 Propulsion machine 20 Propulsion machine main body 21 Corner cutter part 30 Excavation part 31 Water stop body T Large section tunnel

Claims (6)

A method of constructing an underground structure using multiple tunnels,
A step of constructing a preceding tunnel by arranging a box behind the propulsion unit together with excavation of a natural ground by the propulsion unit;
And a step of constructing a subsequent tunnel in parallel with the preceding tunnel by arranging a box at the rear of the propulsion unit together with excavation of natural ground by the propulsion unit,
In the step of constructing the preceding tunnel, an overburden portion is formed on the subsequent tunnel side of the preceding tunnel,
A method for constructing an underground structure, wherein in the step of constructing the trailing tunnel, a part of the trailing tunnel is disposed in the overexcavation portion. The tunnel has a rectangular cross section,
Forming the digging portion at a corner of the preceding tunnel on the side of the subsequent tunnel;
The method for constructing an underground structure according to claim 1, wherein a corner portion of the subsequent tunnel is disposed in the overexcavation portion.   The method for constructing a groundwater structure according to claim 1 or 2, wherein, in the step of constructing the preceding tunnel, a water blocking body is formed by filling the surplus portion with a filler.   3. The underground structure according to claim 1, further comprising a step of filling the surplus portion with a filler to form a waterstop after the step of constructing the trailing tunnel. 4. Construction method.   The method for constructing an underground structure according to claim 4, wherein, in the step of constructing the preceding tunnel, a temporary box is disposed in the overexcavated portion. The propulsion device includes a detachable sub-cutter at a position corresponding to the surplus digging portion;
The construction method for an underground structure according to any one of claims 1 to 5, wherein excavation of the surplus excavation part is performed by changing the sub cutter.

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