JP2019094697A - Construction method of large cross section tunnel and excavation device for large cross section tunnel - Google Patents

Abstract

To provide a construction method of a large cross section tunnel which can reduce a construction cost by efficiently constructing the large cross section tunnel in a short period, and an excavation device for the large cross section tunnel.SOLUTION: A first expansion rectangular propulsion pipe 5 having a contour shape corresponding to a contour of a first excavation unit is installed in the ground by a propulsion jack while developing a propulsion pipe excavation hole by using the first excavation unit which is formed by connecting a plurality of excavators in parallel with one another in a horizontal direction or a vertical direction. The first expansion rectangular propulsion pipe 5 has a substantially-oblong frame shape vertical to an extension direction in a cross section, and reinforced by installing a temporary columnar support 9 at its middle part in a longitudinal direction. Also, the plurality of first expansion rectangular propulsion pipes 5 and a plurality of rectangular propulsion pipes 11 are installed at up-and-down two stages in parallel with each other, and the first expansion rectangular propulsion pipes 5 and the rectangular propulsion pipes 11 are connected and integrated to each other by a joint part, thus constructing a lining body 12. By removing a portion not related to a structure of the large cross section tunnel 13 from a small cross section tunnel of the lining body 12, the large cross section tunnel 13 is constructed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for constructing a large cross section tunnel in which a large cross section tunnel is constructed after a plurality of rectangular propelling pipes are juxtaposed to construct a tunnel lining body, and for installing a rectangular propelling pipe for a large cross section tunnel. It relates to a digging device.

In recent years, when constructing underground underground crossing tunnels under roads, railways, etc., construction using a large cross section split shield method has been proposed in order to avoid obstacles to ground traffic by the cut-and-cut method. The large cross section split shield construction method is a construction method of a large cross section tunnel (harmonica construction method) in which a tunnel and an underpass are economically built in a short period of time by constructing and connecting a plurality of small cross section tunnels by shield construction.
In this construction method, after excavating a plurality of small cross section rectangular tunnels, the steel shells constituting the small cross section tunnel are removed, the reinforcing bar for large cross section tunnel is assembled, concrete is cast and large cross section It is to build a box tunnel.

  For example, as shown in FIG. 10, the drilling pipe drilling hole is excavated with one drilling machine, and ten rectangular propulsion pipes 101 are sequentially arranged in parallel in the upper and lower rows and connected to each other to construct the lining body 100 Was. Then, after constructing the road tunnel 102 for going up and the road tunnel 103 for going down inside the lining structure 100, unnecessary steel shells inside were removed to construct a large cross section tunnel.

  In the construction method of the lining body described in Patent Document 1, a leading rectangular propulsion pipe is installed in the ground while creating a drilling hole for a propulsion pipe with one excavator. Next, repeatedly installing the trailing rectangular propulsion pipe in the ground while creating the drilling pipe drilling hole with the excavator using the preceding rectangular propulsion pipe as a guide, and ten rectangular propulsion pipes are arranged in parallel vertically and horizontally They were arranged and connected to each other to construct a lining body.

Japanese Patent Application Laid-Open No. 2005-200860

  However, in the construction method of the large cross section tunnel described in Patent Document 1, the drilling pipe for the propelling pipe is excavated by the number of rectangular propelling pipes constituting the small cross section tunnel with one excavator, and the rectangular propelling pipe is propelled It was necessary to repeat the installation of multiple rectangular propulsion pipes. Therefore, there is a problem that the construction takes a long time because it takes time to set up a rectangular propelling pipe in the drilling and propulsion drilling holes by the drilling machine and disassemble, carry out and reassemble the drilling machine in the start shaft and the arrival shaft. The In addition, since it is necessary to cut unnecessary portions of the steel shells of the ten rectangular propulsion pipes after construction of the lining body and discard them in large quantities, there is a problem that the cost is increased.

  This invention is made in view of such a subject, and the construction method of the large section tunnel which can construct a large section tunnel efficiently in a short period of time conventionally, and can make construction cost low, and An object of the present invention is to provide a digging device for a large cross section tunnel.

That is, in the method of constructing a large cross section tunnel according to the present invention, after constructing a lining body by arranging a plurality of rectangular propulsion pipes side by side and integrating a plurality of small cross section tunnels, In the construction method of a large cross section tunnel where a large cross section tunnel is constructed by removing a portion not related to the structure of the above, a drilling unit for propelling pipe is formed by a drilling unit in which a plurality of drilling machines are connected horizontally and vertically. According to the present invention, the lining body of the large cross section tunnel is characterized in that at least a part of the small cross section tunnel is constructed by installing the outer shape extended rectangular propulsion pipe corresponding to the outer shape of the drilling unit. At the time of construction, the ground is simultaneously drilled with multiple drilling machines of the drilling unit, and the outer pipe-shaped rectangular propulsion pipe corresponding to the outer shape of the drilling unit is installed in the drilling pipe drilling pipe, Since the number of excavations for constructing the body and the number of installation of the rectangular propulsion pipe can be reduced, the lining structure of the large cross section tunnel can be constructed efficiently in a short time than before, and cut and discarded in the large cross section tunnel construction The construction cost can be reduced because the amount of steel shell of the rectangular propulsion pipe can be reduced.

In addition, a temporary support or temporary beam may be installed in the expanded rectangular propulsion pipe.
Even if the extended rectangular propulsion pipe installed in the ground has a shell shape corresponding to the outer shape of the drilling unit in which a plurality of excavators are juxtaposed, the temporary prop The strength can be reinforced by installing temporary beams.

The digging apparatus for a large cross section tunnel according to the present invention comprises a digging unit formed by arranging a plurality of excavators horizontally or vertically juxtaposed and connected to each other, and installed on the rear surface of the digging unit to obtain an outline of the digging unit. It is characterized by comprising: an extended rectangular propelling pipe having a corresponding outer shell shape; and a propelling jack for propelling the expanded rectangular propelling pipe along a propelling pipe drilling hole created by the drilling unit.
According to the present invention, it is possible to unify by connecting a plurality of single excavators in parallel without connecting a large excavator, and integrating them, and by increasing the size of the extended rectangular propulsion pipe, the construction of a small cross section tunnel The efficiency can be improved, the construction period can be shortened, and the construction cost can be reduced.

  According to the construction method of the large cross section tunnel and the digging apparatus for the large cross section tunnel according to the present invention, the drilling unit for drilling pipe can be drilled by the drilling unit connected by using a plurality of drilling machines in parallel Since a corresponding enlarged outer diameter rectangular propelling pipe can be installed, construction of a large cross section tunnel can be performed more efficiently, the construction period can be shortened, and the steel shell of the rectangular propelling pipe to be discarded can be reduced. Can be reduced.

It is a front view of the excavation unit in a first embodiment of the present invention. (A) is a front view of an expansion rectangular propulsion pipe, (b) is a front view of a basic rectangular propulsion pipe. It is a schematic diagram which shows the construction process of a lining body, (a) is a longitudinal cross-sectional view, (b) is a horizontal sectional view. (A)-(f) is a schematic diagram which shows the construction process of the large cross section tunnel by embodiment. It is a front view of the large section tunnel by a first embodiment. It is a schematic diagram which shows the large cross section tunnel and lining body by 2nd embodiment. It is a front view of the excavation unit in a second embodiment. It is a schematic diagram which shows the large section tunnel and lining body by 3rd embodiment. It is a front view of the drilling unit in 3rd embodiment. It is a schematic diagram which shows the conventional lining body and a large section tunnel.

Hereinafter, a method of constructing a large cross section tunnel and a digging apparatus for the large cross section tunnel according to an embodiment of the present invention will be described with reference to FIGS.
1 to 5 show a digging apparatus 1 for a large cross section tunnel and a method of constructing the large cross section tunnel according to the first embodiment. In this embodiment, a plurality of first expanded rectangular propulsion pipes 5 are arranged in parallel by the digging device 1 to form a earth retaining structure for large-scale tunnel construction, and then a large-scale permanent tunnel is constructed.
The digging apparatus 1 for a large cross section tunnel according to the present embodiment shown in FIGS. 1 to 3 is formed by connecting a plurality of, for example, two parallel single excavators 2 having a substantially rectangular plate shape used in the above-described prior art. The row of the first expanded rectangular propelling pipe 5 to be propelled into the first drilling unit 3 and the propelling pipe drilling hole 7 created by drilling by the first drilling unit 3 and the rear surface of the first expanding rectangular propelling pipe 5 And a movable jack 6 for moving. In addition, as described later, the first expanded rectangular propulsion pipe 5 has a width about twice that of the rectangular propulsion pipe 11 installed by the single drilling machine 2.

The first drilling unit 3 has two drilling machines 2 installed in parallel in the horizontal direction, and they are connected to each other by a bolt or the like at the connecting portion 4 and are simultaneously drilled. A plurality of, for example, two swing cutters 8 are mounted on the front of each excavator 2. Alternatively, a rotary cutter may be mounted. The plurality of rocking cutters 8 can be rocked around the rocking axis, respectively, and can be controlled so as not to overlap the digging ranges with each other.
For example, two swinging cutters 8 are arranged in the same plane or both in a back-and-forth manner, and each swinging cutter 8 excavates only its own share range. When digging a rectangular cross section, the rectangular cross section is equally divided into two, for example, and two rocking cutters 8 cut the ground while rocking within each divided range. The swinging of the swinging cutter 8 can be controlled so that both swing in opposite directions about the swinging axis.

  The first drilling unit 3 simultaneously drills in the ground with two excavators 2 connected to each other, and forms a drilling hole 7 for a propelling pipe having an outer shape of two excavators 2. In addition, it is also possible to mutually connect three or more excavators 2 in parallel or up and down as the first drilling unit 3 and simultaneously drill. On the other hand, when the number of excavators 2 connected to the first drilling unit 3 increases, the width of the drilling increases, which may cause ground subsidence at the surface portion of the drilling hole 7 for a propulsion pipe in the ground.

As shown in FIG. 2A, the first expanded rectangular propulsion pipe 5 has an outer shape of the first drilling unit 3 which is two units of the excavator 2. The first expanded rectangular propulsion pipe 5 is formed, for example, in a rectangular cylindrical shape having a cut surface (cross section) perpendicular to the extension direction of the tunnel, which has, for example, a substantially rectangular frame shape, and is formed of, for example, a steel shell. . The length of the top plate 5b and the bottom plate 5c is about twice the length of the side walls 5a on both sides, and the first extended rectangular propulsion tube 5 has a length of the top plate 5b and the bottom plate 5c to reinforce its strength. For example, a steel temporary support 9 may be connected to the direction intermediate portion. The temporary support columns 9 can be installed at appropriate intervals along the extension direction of the first expanded rectangular propulsion pipe 5.
In addition, what is shown in FIG.2 (b) is the rectangular propulsion pipe 11 provided with the external shape corresponding to the external shape of one drilling machine 2, and has a basic shape and a dimension used by a prior art etc. The length of the top plate and the bottom plate is set to half the length of the top plate 5 b and the bottom plate 5 c of the first expanded rectangular propulsion tube 5. Similarly, the rectangular propulsion pipe 11 is formed of a steel shell.

The jack for propulsion 6 for propelling the first expanded rectangular propulsion pipe 5 shown in FIGS. 3 (a) and 3 (b) is to press an appropriate portion of the rear end face of the first expanded rectangular propulsion pipe 5 or the rectangular propulsion pipe 11. There are several installed. In FIG. 2 (a), (b), an example of the installation position of the jack 6 for propulsion which presses the rear end surface of the 1st extended rectangular propulsion pipe 5 or the rectangular propulsion pipe 11 is shown with the dashed-two dotted line.
In the present embodiment, as shown in FIG. 4 (f), the four first expanded rectangular propulsion pipes 5 and the two rectangular propulsion pipes 11 are combined and constructed in two stages, upper and lower, so that the covering shown in FIG. The lining work body 12 having the same external dimensions as the work body 100 is constructed. A large cross-section tunnel 13 constructed by removing unnecessary steel shells from the lining construction 12 is constructed by an ascending road tunnel 14a and a descending road tunnel 14b which are separated from each other.

The combination arrangement of the first expanded rectangular propulsion pipe 5 and the rectangular propulsion pipe 11 in the lining construction 12 can be set arbitrarily. In the lining body 12 shown in FIG. 4 (f), although the rectangular propulsion pipes 11 are respectively disposed between the two first expanded rectangular propulsion pipes 5 arranged in the upper and lower horizontal directions, the first expanded rectangular The combination arrangement of the propelling pipe 5 and the rectangular propelling pipe 11 can be arbitrarily selected.
For example, two rectangular propulsion pipes 11 may be installed on the left side of the upper and lower sides, and two first expanded rectangular propulsion pipes 5 may be installed respectively on the upper and lower sides of the right side. The two first expanded rectangular propelling pipes 5 may be installed horizontally, and the two rectangular propelling pipes 11 may be installed on the upper and lower ends of the right side thereof. Alternatively, the rectangular propulsion pipe 11 may not be provided.

The digging apparatus 1 according to the present embodiment has the above-described configuration, and next, a method of constructing the large cross section tunnel 13 will be described with reference to FIGS.
First, as shown in step 1 of FIG. 3 and FIG. 4 (a), the ground in the ground is excavated horizontally using the first excavation unit 3 in which the two excavators 2 are connected from within the starting shaft 15 Then, a drilling pipe drilling pipe 7 having a substantially rectangular cross section is excavated and constructed. Following the first drilling unit 3, the row of first expanded rectangular propulsion pipes 5 is propelled by the propulsion jacks 6 into the protuberance hole 7 to construct a widened small cross section tunnel 16. This first expanded rectangular propulsion pipe 5 is referred to as a leading expanded rectangular propulsion pipe 5A. In the first expanded rectangular propelling pipe 5, a temporary support 9 was installed at the middle portion at the time of construction to reinforce the strength, and the top plate 5b and the bottom plate 5c were not deformed by earth pressure.

Although the first expanded rectangular propulsion pipe 5A may be a propulsion pipe at any position of the four first expanded rectangular propulsion pipes 5 among the six (six rows) shown in FIG. 4 (f), the present embodiment In this case, the first expanded rectangular propulsion pipe 5 at the left end of the upper stage was used. In this case, since the first drilling unit 3 and the first expanded rectangular propulsion pipe 5 are used, twice as many cuts in one construction as compared to the case where one excavator 2 and a single rectangular propulsion pipe 11 are used A widened small cross section tunnel 16 having an area can be constructed.
When the first drilling unit 3 reaches the reaching shaft, it is dismantled, carried out, put into the starting shaft 15, reassembled, and used for excavation of the ground.

Next, as shown in step 2 of FIG. 4B, the lower side of the first expanded rectangular propelling pipe 5A is excavated by the first drilling unit 3 and a row of the first expanded rectangular propelling pipe 5 is installed, A trailing expansion rectangular propulsion pipe 5B was constructed. The trailing expansion rectangular propulsion pipe 5B was constructed along the leading expansion rectangular propulsion pipe 5A using the leading expansion rectangular propulsion pipe 5A as a guide. At the time of construction of the trailing expansion rectangular propulsion pipe 5B, for example, the first digging unit 3 and the trailing for the trailing groove or ridge (not shown) provided in the tunnel extension direction of the outer peripheral portion of the leading expansion rectangular propulsion pipe 5A. The ridges or grooves provided on the outer peripheral portion of the expanded rectangular propulsion pipe 5B are slidably fitted so as to be able to guide and travel.
In step 3 shown in FIG. 4 (c), the drilling pipe for the propelling pipe is excavated by the single excavator 2 on the side of the leading expanded rectangular propelling pipe 5A and the rectangular propelling pipe 11 is installed. I built 11B. The trailing rectangular propelling pipe 11B was constructed along the leading expanding rectangular propelling pipe 5A with the leading expanding rectangular propelling pipe 5A as a guide by the grooves and the ridges described above. A small cross section tunnel 17 can be constructed by this rectangular propulsion pipe 11.

  Similarly, in step 4 shown in FIG. 4 (d), a single excavating operation is performed in the lower part of the trailing rectangular propulsion pipe 11B using at least one of the trailing rectangular propulsion pipe 11B and the trailing expansion rectangular propulsion pipe 5B as a guide. A trailing rectangular propulsion pipe 11 </ b> C was constructed by excavating the propulsion pipe drilling hole with the machine 2 and installing a row of rectangular propulsion pipes 11. The trailing rectangular propelling pipe 11C is constructed along the leading expanding rectangular propelling pipe 5A by using at least one of the trailing expanding rectangular propelling pipe 5B and the trailing rectangular propelling pipe 11B as a guide by the groove portion and the ridge described above.

Next, in step 5 shown in FIG. 4 (e), the first drilling unit 3 excavates the drilling pipe drilling hole 7 by the first drilling unit 3 with the trailing rectangular propulsion pipe 11 B as a guide, and the first expanded rectangular propulsion pipe 5 The rear extended rectangular propulsion pipe 5C is constructed by installing the column of. The trailing extended rectangular propelling pipe 5C was constructed along the trailing rectangular propelling pipe 11B by using the trailing rectangular propelling pipe 11B as a guide by the grooves and the ridges described above.
Also, in step 6 shown in FIG. 4 (f), at least one of the trailing rectangular propulsion pipe 11C and the trailing rectangular propulsion pipe 11C is used as a guide below the trailing expanded rectangular propulsion pipe 5C. A trailing expansion rectangular propulsion pipe 5D was constructed by drilling the propulsion pipe drilling hole 7 with the unit 3 and installing a row of first expanded rectangular propulsion pipes 5. The trailing extended rectangular propelling pipe 5D was constructed along the trailing expanding rectangular propelling pipe 5C by using at least one of the trailing rectangular propelling pipe 11C and the trailing expanding rectangular propelling pipe 5C as a guide by the grooves and the ridges described above .

Thus, by sequentially constructing the four first expanded rectangular propelling pipes 5 and the two rectangular propelling pipes 11, as shown in FIG. 4 (f), six integrated small cross section tunnels A lining construction 12 consisting of 16, 17 was constructed. The first expanded rectangular propulsion pipe 5 and the rectangular propulsion pipe 11 are connected to each other by a joint portion, and the joint portion of the adjacent first expanded rectangular propulsion pipe 5 and the rectangular propulsion pipe 11 is subjected to water sealing treatment Do. The lining structure 12 forms an earth retaining structure for the construction of the large cross section tunnel 13.
Thereafter, while removing unnecessary portions of the steel shells constituting the first expanded rectangular propelling pipe 5 and the rectangular propelling pipe 11 inside the lining body 12, the construction of the large-scale tunnel 13 of the present construction is performed. The large cross section tunnel 13 can be completed by reinforcing the up road tunnel 14a and the down road road 14b from the lining body 12 as shown in FIG. Moreover, since the outer shell of the large cross section tunnel 13 forms the earth retaining structure provided with a water stop structure, the construction of the large cross section tunnel 13 can be realized safely.

  In the present embodiment, the lining construction 12 is constructed by the combined construction of the first drilling unit 3 and the first expanded rectangular propulsion pipe 5, the excavator 2, and the rectangular propulsion pipe 11 in the above description, but a single excavation The construction of the small cross section tunnel 17 by the aircraft 2 and the rectangular propulsion pipe 11 may not necessarily be included. The single drilling machine 2 and the rectangular propulsion pipe 11 can be appropriately combined with the construction method using the first excavation unit 3 and the first expanded rectangular propulsion pipe 5 according to the outer dimensions of the lining body 12 to be constructed.

As described above, according to the digging apparatus 1 and the large cross section tunnel construction method for the large cross section tunnel 13 according to the first embodiment, the first digging unit 3 and the first expanded rectangular propulsion pipe in which the two excavators 2 are connected Since the construction is performed using the single drilling machine 2 and the rectangular propulsion pipe 11, the number of digging operations and the number of installation of the first expanded rectangular propulsion pipe 5 and the rectangular propulsion pipe 11 can be reduced. Therefore, the construction efficiency of the large cross section tunnel 13 is increased, and the construction period and the construction cost can be reduced.
In addition, since the first expanded rectangular propulsion pipe 5 having a substantially rectangular frame cross section and having a width twice the width of the rectangular propulsion pipe 11 is used, when constructing the large cross section tunnel 13 after construction of the lining body 12, It is possible to reduce the amount of cutting and removing the 12 inner steel shells. Also in this respect, the construction efficiency can be enhanced and the construction cost can be reduced.
In addition, since the temporary support 9 is installed in the middle portion of the first expanded rectangular propulsion pipe 5 having a substantially rectangular frame shape in cross section to reinforce the strength, the first expanded rectangular propulsion pipe 5 is deformed by the earth pressure in the ground. It can be suppressed.

  As mentioned above, although the construction method of large section tunnel 13 by a first embodiment of the present invention and digging device 1 used with this construction method were explained in detail, the present invention is not limited to the above-mentioned first embodiment, Appropriate changes, substitutions, and the like can be made without departing from the scope of the present invention, and all of these are included in the present invention. Hereinafter, other embodiments, modified examples, and the like of the present invention will be described, but the same reference numerals are used for the same or similar parts and members as the above-described embodiment, and the description will be omitted.

In the first embodiment described above, the temporary support 9 is installed and reinforced in the middle portion of the first expanded rectangular propulsion pipe 5, but the side wall 5a, the top plate 5b, and the bottom plate 5c of the first expanded rectangular propulsion pipe 5 are reinforced. In the case of reinforcing by increasing the thickness of steel, it is not always necessary to install the temporary support 9.
Moreover, in the construction method of the large cross section tunnel 13 in the first embodiment, the first expanded rectangular propelling pipe 5 in the upper stage is made to precede and installed in the construction of the lining construction 12 to make the pre-expanded rectangular propelling pipe 5A, It goes without saying that the first expanded rectangular propulsion pipe 5 or the rectangular propulsion pipe 11 may be installed in advance from the lower side.

FIG. 6 is a view showing a large cross section tunnel 13 and a lining body 20 according to a second embodiment of the present invention.
In the lining body 20 shown in FIG. 6, in the first embodiment described above, the rectangular propulsion pipes 11 are respectively installed between the first expanded rectangular propulsion pipes 5 in the upper and lower stages, but in the second embodiment, A second expanded rectangular propulsion pipe 21 having a substantially rectangular frame shape in cross section and having an outer shape in which two rectangular propulsion pipes 11 are connected in the direction is installed.
The temporary beam 22 was disposed at the center in the longitudinal direction of the rectangular frame-like cross section of the second expanded rectangular propulsion tube 21 to reinforce its strength.
In order to propel the second expanded rectangular propulsion pipe 21, as shown in FIG. 7, a second excavation unit 18 in which single excavators 2 are vertically connected is used.

  Therefore, in the lining body 20 according to the second embodiment, at least any of the groove portions and the ridges provided on the outer peripheral portion of the two leading extended rectangular propulsion pipes 5A constructed in the upper and lower stages and the trailing expanded rectangular propulsion pipe 5B. Guided by one side, the ground was drilled by the second drilling unit 18 and a row of second expanded rectangular propulsion pipes 21 expanded vertically was installed. Thereafter, with the second expanded rectangular propelling pipe 21 as a guide, the propelling pipe excavating hole 7 was excavated by the first excavating unit 3, and the trailing expanded rectangular propelling pipes 5C and 5D were installed.

  According to the construction method of the large cross section tunnel 13 according to the second embodiment, the lining work body 20 of the small cross section tunnel 16 composed of the row of the five first expanded rectangular propelling pipes 5 and the second expanded rectangular propelling pipe 21 is constructed Since it is possible, the number of times of excavation and propulsion can be further reduced, the construction efficiency can be improved, and the construction period can be reduced. In addition, the amount of cutting and discarding of the steel shell inside can be further reduced when constructing the large cross section tunnel 13 after the construction of the lining structure 20.

Next, FIG. 8 is a view showing a large cross section tunnel 13 and a lining body 24 according to a third embodiment of the present invention.
When constructing the lining body 24 of the large cross section tunnel 13 according to the third embodiment shown in FIG. 8, as shown in FIG. 9, a third excavation unit 25 in which three excavators 2 are horizontally connected in parallel is used. It was. Then, in the lining body 24, a third expanded rectangular propulsion pipe 26 having a substantially rectangular cross section having an outer shape corresponding to the outer shape of the third drilling unit 25 is installed.
In the third embodiment, using the first drilling unit 3 and the third drilling unit 25, the first expanded rectangular propulsion pipe 5 and the third expanded rectangular propulsion pipe 26 are respectively installed in the lower stage of the lining body 24. The third expanded rectangular propelling pipe 26 and the first expanded rectangular propelling pipe 5 were respectively installed and connected to the upper stage. Moreover, in the third expanded rectangular propulsion pipe 26, in order to reinforce its strength, a plurality of, for example, two temporary support columns 9 are installed at predetermined intervals.

  According to the construction method of the large cross section tunnel 13 according to the third embodiment, the two first expanded rectangular propelling pipes 5 and the third expanded rectangular propelling pipes 26 are installed in upper and lower two stages and connected by joint parts Since the construction body 24 can be constructed, the number of digging and propulsion can be further reduced, the construction efficiency can be improved, the construction period can be reduced, and the construction cost can be reduced. Moreover, when constructing the large cross section tunnel 13 after the construction of the lining body 24, the amount of cutting and discarding of the steel shell inside can be further reduced.

In addition, also in the second and third embodiments, if the thickness of steel of the side wall, top plate and bottom plate of the second expanded rectangular propulsion pipe 21 and the third expanded rectangular propulsion pipe 26 is increased to reinforce the temporary support 9 or The temporary beam 22 may not be installed.
In the present invention, the first drilling unit 3, the second drilling unit 18, and the third drilling unit 25 are included in the drilling unit. In addition, the first expanded rectangular propulsion pipe 5, the second expanded rectangular propulsion pipe 21, and the third expanded rectangular propulsion pipe 26 are included in the rectangular propulsion pipe.

DESCRIPTION OF SYMBOLS 1 Excavator 2 Excavator 3 First digging unit 5 First expanded rectangular propelling pipe 5A Leading expanded rectangular propelling pipe 5B, 5C, 5D Trailing expanded rectangular propelling pipe 6 Propelling jack 9 Temporary support 11 Rectangular propelling pipe 11B, 11C Row rectangular propulsion pipes 12, 20 and 24 reverse structure 13 large cross section tunnel 14a uphill road tunnel 14b downward road tunnel 18 second excavation unit 21 second expanded rectangular propulsion pipe 22 temporary beam 25 third excavation unit 26 third expansion Rectangular propulsion pipe

Claims (3)

After constructing a lining body by arranging a plurality of rectangular propulsion pipes side by side and integrating a plurality of small cross section tunnels, a portion not related to the structure of the large cross section tunnel is removed from the lining body and a large cross section tunnel is formed. In the construction method of the large section tunnel to construct
At least by installing an extended rectangular propulsion pipe having an outer shape corresponding to the outer shape of the drilling unit while creating a drilling hole for a propulsion pipe with a drilling unit in which a plurality of excavators are connected horizontally and vertically in parallel and connected. A construction method of a large cross section tunnel characterized by constructing a part of the small cross section tunnel.   The construction method of the large cross section tunnel described in Claim 1 which installed the temporary support | pillar or temporary beam in the said expansion rectangular propulsion pipe | tube. A drilling unit formed by arranging a plurality of excavators horizontally or vertically in parallel and connecting them;
An extended rectangular propulsion pipe installed on a rear surface of the drilling unit and having an outer shape corresponding to the outer shape of the drilling unit;
A propelling jack for propelling the extended rectangular propelling pipe along a propelling pipe drilling hole created by the drilling unit;
A digging device for a large cross section tunnel characterized by comprising.

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