JP4083336B2 - How to build a tunnel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a tunnel having a large cross section in the ground.
[0002]
[Prior art]
Conventionally, as a method of constructing a tunnel having a large cross section in the ground, a plurality of pipes are inserted into the ground so as to be parallel to each other to form an outer body, which is surrounded by a lower ground or outer body of the outer body. The so-called pipe roof method is known for excavating the ground, but in this method, it is necessary to provide a large start shaft for inserting the pipe into the ground and a reach shaft for reaching the pipe on the tip side. In addition, when a long pipe is used, it is difficult to insert the pipe into the ground, so that it can be used only for the construction of a relatively short tunnel.
[0003]
For this reason, as shown in FIG. 9 , as a method of constructing a large-section tunnel replacing the pipe roof construction method, advanced pits A and B that are parallel to each other with a predetermined interval in the ground are excavated. The steel pipe C curved in an arc shape from the start side advanced mine A with the other advanced mine B as the arrival side is inserted into the ground toward the arrival side advanced mine B, and the tip of the steel pipe C is made the arrival advanced mine B. After sequentially performed for each desired interval work advanced anti lengthwise to reach, while the subsequent is not the sheath pipe E as shown in FIG. 10 from start side advanced anti a a steel tube C as a guide in each steel C small drilling device D is reached, accordingly Thereafter, shell by injecting a soil improvement material into the ground in a small diameter drilling device D while pulling back the small diameter drilling device D to start side advanced anti a with sheath pipe E as shown in FIG. 11 Form the body F, the inner ground of this outer body F Methods have been developed to build tunnels by drilling.
[0004]
[Problems to be solved by the invention]
However, in the above tunnel construction method, the arcuately curved steel pipe C is arranged in an erected state between the advanced mines A and B on both sides, so that a long steel pipe C is required and its handling is complicated. In addition, accuracy is required to reach the predetermined location of the arrival side advanced mine B from the start side advanced mine A, and the work is difficult. In addition, the steel pipe C is inserted into the ground only from one advanced mine. Therefore, it takes a lot of labor to insert a large number of steel pipes C into the ground, and work to fix the tip of the steel pipe C reaching the arrival side advanced mine B to the arrival side advanced mine B Need.
[0005]
When the ground improvement material is injected into the ground around the steel pipe C inserted into the ground between the two advanced mines, as described above, the small-diameter excavator D using the steel pipe C as a guide from the start side advanced mines A. , And pushes the subsequent sheath pipe E to reach the arrival side advanced mine B, and then retracts the small diameter excavator D by retracting the sheath pipe E to the start side advanced mine A. Since the ground improvement material is injected and injected from D, it takes a lot of labor and labor to form the outer body F by the ground improvement. Moreover, adjacent steel pipes C and C are close to each other in the ground. In such a case, there is a problem that when the small-diameter excavator D is dug using one steel pipe C as a guide, the other steel pipe C may hinder the dug.
[0006]
The present invention has been made in view of such problems, and an object of the present invention is to configure a tunnel outer body in the ground between advanced mine excavated at intervals in the ground. The tube can be inserted easily and efficiently, and it is possible to form a thick outer shell. In addition, when injecting ground improvement material into the ground, the injection work can be easily performed and a large section tunnel can be formed. Is to provide a tunnel construction method that can be constructed efficiently.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 of the present invention includes a step of forming advanced pits parallel to each other at appropriate intervals in the ground, and a predetermined interval in the longitudinal direction between the two advanced mines. An arc-shaped tube is inserted into the ground between these advanced pits through the tube insertion hole drilled every time, and the tip of the tube from one advanced mine side and the tube from the other advanced mine side. And inserting the ground improvement material into the ground around the pipe through each pipe, and inserting the ground improvement material into the ground around the middle of the ground between the advanced pits. A tunnel construction method comprising a step of forming an improved ground layer and a step of excavating the ground inside the tunnel outer shell formed by these improved ground layers, wherein the pipes drilled in both advanced mine pipes A pipe inclined obliquely forward from the body insertion hole to the axial direction of both advanced mine shafts Alternately inserting the pipe into the ground and inserting the pipe inclined obliquely backward into the ground, and the pipe inserted diagonally forward from one advanced mine and the other A pipe inserted diagonally backward from an advanced mine, a pipe inserted diagonally backward from one advanced mine, and a pipe inserted diagonally forward from the other advanced mine A tunnel shell made up of pillar-shaped improved ground layers intersecting in a plane twill weave is formed by injecting ground improvement material through the pipes into the ground around each pipe with the bottom positioned It is characterized by that.
[0008]
According to a second aspect of the present invention, there is provided a step of forming an advanced mine parallel to each other at an appropriate interval in the ground, and a tubular body drilled at predetermined intervals in the length direction in both the advanced mine Inserting arc-shaped pipes into the ground between these advanced pits through the insertion holes, and injecting ground improvement material into the ground around the pipes through each pipe to form columnar improved ground layers And a tunnel construction method comprising a step of excavating the ground inside the tunnel outer body formed by these improved ground layers, the pipe inserted into the ground from the one advanced mine side and the other Improved ground layer inserted into the ground surrounding one of the pipes, with the pipes inserted into the ground from the side of the advanced pit inserted alternately into a flat staggered pattern with a certain distance in the front-rear direction. And the improved ground layer injected into the surrounding ground of the other pipe It is characterized in that to form a mutually tunnel enclosures made by continuous.
[0009]
[Action]
First, two advanced pits are excavated and formed in the ground so as to be parallel to each other at a desired interval in the left-right direction. These advanced mine excavations can be performed using, for example, a shield excavator. After excavation of the advanced mine or according to the excavation, both advanced mines are used as the start pits of the pipes, and pipes curved in an arc shape outward from these advanced mines are inserted into the ground between the two advanced mines. At least the tip portions of these pipes facing each other in the intermediate portion between the advanced pits are made to be in a superimposed state or a crossed state. Such tube insertion work is performed at predetermined intervals in the length direction in both advanced mines, and a tube row is formed in the ground between both advanced mines.
[0010]
Next, a tunnel with a large cross-section is constructed by excavating the ground inside this tubular body row. At that time, ground improvement materials that solidify the ground into the tubular body are supplied from both advanced mine sides, and the pipe After improving the ground around the pipe body by injecting and injecting into the ground from a number of injection holes pre-drilled in the body, and forming the tunnel outer body together with the pipe body, the inner ground of the outer body Excavate.
[0011]
In addition, when inserting pipes into the ground from both advanced mines, insertion forms that intersect with each other when the tips of both pipes are viewed from the front, or insertions that overlap the length direction of the advanced mines, that is, the front-rear direction Since it is in the form, the construction length can be short, and it becomes possible to form an outer body that is accurate and stable in construction. In this case, the tube row is one-stage (one-line formation), but it is a multi-stage tube with two or more stages above and below by inserting it from the advanced mine toward the ground in a staggered manner in the length direction of the advanced mine. A body row can be formed, pipes can be arranged densely, and an outer body having a large thickness and high strength can be formed, which hardly causes inflow of groundwater and collapse of earth and sand.
[0012]
Furthermore, the pipe inserted into the ground diagonally forward from one advanced mine into the ground by inserting the pipe into the ground diagonally forward and diagonally backward from both advanced mine shafts from both advanced mine shafts. And a plurality of other pipes on one improved ground formed by injecting and injecting a ground improvement material from the other advanced mine corresponding to the pipe and the pipe inserted obliquely rearward into the ground. The improved ground portion overlaps with the planar twill shape, and the occurrence of unimproved portions in the case where they are constructed in parallel with each other can be surely eliminated, and a stronger outer body can be formed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal front view showing a subway station building as a large section tunnel, which is formed at a predetermined interval on the left and right. A double lane is formed by two advanced mines 1 and 2, and a large cross-section space 3 is provided between these advanced mines 1 and 2 by excavation of a large cross-section tunnel. A tunnel outer body 5 for constructing the ceiling wall of the home 4 is formed.
[0014]
The tunnel outer body 5 includes a large number of pipe bodies 7 and 8 that are curved in an arc from the pair of peripheral circumferences of both advanced mines 1 and 2 and are inserted into the ground 6, and these pipe bodies. 7 and 8 and improved ground layers 9a and 9b. After the tunnel outer body 5 is formed, a tunnel T having a large cross section is formed by excavating the ground inside the tunnel outer body 5 to form the station building. Is done.
[0015]
The concrete construction method of the tunnel T having such a large cross section will be described. First, the advanced mine 1 and 2 are horizontally arranged using a shield excavator (not shown) with a predetermined interval left and right in the ground. Drilled and formed in parallel. After excavation of these advanced mines 1 and 2, or after excavation, in a place where a large cross-section space portion 3 such as a platform 4 should be constructed, as shown in FIG. Inserted into the upper ground 6 between these advanced mines 1 and 2 from the circumference are pipes 7 and 8 made of small-diameter steel pipes having a constant diameter and curved in an outward arc shape toward the opposing advanced mine. In the ground above the intermediate portion between the advanced mine 1 and 2, the tip of the tube 7 inserted into the ground 6 from the pit 1 and the tip of the tube 8 inserted into the ground 6 from the other advanced mine 2 Make sure they are stacked close to each other. In addition, what is necessary is just to form the pipe bodies 7 and 8 in the length which does not reach the other advanced mine, ie, the length shorter than the construction distance length between both the advanced mines 1 and 2.
[0016]
In order to insert and arrange the pipe bodies 7 and 8 from the advanced mines 1 and 2 into the ground 6, first, as shown in FIG. 4 , the pipe bodies 7 and 8 are slightly larger than the pipe bodies. A bit 11 having a diameter is rotatably mounted, a hollow flexible shaft 12 is inserted into the tube, and the tip thereof is inserted into a keyhole-shaped engagement hole 13 provided in the center of the back surface of the bit 11. The protrusion 14 provided on the outer periphery of the tip is locked in the engagement hole 13, and in this state, the flexible shaft 12 is rotated on the advanced mine side and pressure water is supplied through the hollow of the flexible shaft 12, This is performed by propelling the tubes 7 and 8 while perforating the ground by injecting into the ground from the nozzle 15 drilled in 11. At this time, since the tubular bodies 7 and 8 are curved outward, they are inserted into the ground in an arc shape by propulsion.
[0017]
When the tubular bodies 7 and 8 are inserted in a state where their tip portions overlap each other in the middle of the upper ground between the advanced mines 1 and 2 as described above, the flexible shaft 12 is moved as shown in FIG. By rotating in the opposite direction, the tip projection 14 and the engagement hole 13 are unlocked, and then the flexible shaft 12 is retracted to be recovered in the advanced mine 1 and 2, respectively. Used for 7 and 8 insertion work.
[0018]
In addition, in order to insert the pipe bodies 7 and 8 into the ground 6 from the inside of the advanced mines 1 and 2, the pipes drilled at predetermined intervals in the length direction in the upper peripheral parts of the advanced mines 1 and 2 facing each other. Although it is performed through the body insertion hole 16, when the advanced mine 1 or 2 is dug by a shield excavator, the backfill injection hole provided in the shield excavator can be used as the tube insertion hole. Further, as shown in FIG. 3 , the pipe bodies 7 and 8 are bent while supplying a long straight pipe to a bending machine 17 movably installed in the advanced mine 1 and 2 and being bent to a predetermined radius of curvature. It is inserted into the ground from the machine 17 through the tube insertion hole 16. Alternatively, the tubular bodies 7 and 8 may be formed by sequentially adding a curved tube of a fixed length that has been bent in advance without using the bending machine 17.
[0019]
When the insertion work of the one pipe body 7 or 8 from the advanced mine 1 or 2 into the ground is completed, the same operation as described above is performed again at the next insertion position that is slightly spaced from the insertion position in the length direction of the advanced mine. The pipes 7 and 8 are inserted into the ground through the opposing pipe insertion holes 16 and 16 of the advanced mines 1 and 2, and thereafter, in the same manner, at predetermined intervals in the length direction of the advanced mines 1 and 2. Tube bodies 7 and 8 are sequentially inserted into the ground 6 from the tube insertion holes 16 and 16 drilled every time, and the distal ends are adjacent to the front and rear as a set of the tube bodies 7 and 8 facing in the front-rear direction in the ground. A tube row is formed in which a set of tube bodies 7 and 8 are arranged with a predetermined interval.
[0020]
When there is no groundwater in the ground 6 and the geology is relatively stable, the tube row prevents the ground from collapsing. Therefore, the tunnel shell 5 is formed only by the tube row and the outer shell 5 is formed. It is only necessary to form the large cross-section space portion 3 by excavating the inner ground of the tube, but in the case of a ground that tends to collapse, the water is passed through the tube bodies 7 and 8 of each set after the tube bodies 7 and 8 are inserted. Supplying liquid ground improvement material 18 such as glass or cement milk, mortar, etc., and injecting and pouring into ground 6 around pipes 7, 8 and solidifying the ground improvement material 18, impervious improved ground Layers 9a and 9b are formed. The process of forming the improved ground layers 9a, 9b may be performed sequentially in parallel with the process of inserting the tubular bodies 7, 8 into the ground 6, or after the formation of the plurality of sets of tubular bodies. Also good.
[0021]
The ground improvement material 18 is injected and injected into the ground 6 through the pipes 7 and 8 as follows. That is, as shown in FIG. 6 , the pipe bodies 7, 8 are preliminarily provided with a number of extraction holes 19 in the circumferential direction and the length direction in the peripheral wall, and the pipe bodies 7, 8 are formed in the ground 6. Then, the injection pipe 20 is inserted into the pipe bodies 7 and 8 from the advanced wells 1 and 2 and injected and injected from the injection pipe 20 through the extraction hole 19. Packers 21 and 21 that are in sliding contact with the inner wall surfaces of the pipe bodies 7 and 8 are fixed to the distal end portion of the injection tube 20 with a small gap in the length direction, and the distal end portions between these packers 21 and 21 are fixed. An injection hole 22 is drilled in the ground, and the ground improvement material 18 is injected from the injection hole 22 into the tube portion between the packers 21 and 21 while moving the injection tube 20 in the length direction within the tubes 7 and 8. It is filled and injected and injected into the ground from the pouring holes 19 of the tubes 7 and 8 corresponding to the space between the packers 21 and 21.
[0022]
In this way, improved ground layers 9a and 9b are formed around the pipe bodies 7 and 8, respectively. At this time, injection and injection are performed from the pouring holes 19 over the entire length of the pair of pipe bodies 7 and 8, respectively. By using the ground improvement material 18, the column-like improved ground layer in which the ground 6 around the tubular bodies 7 and 8 is long in the longitudinal direction of the tubular bodies 7 and 8 and both ends are continuous with the paired peripheral surfaces of the advanced mine 1 and 2. 9 is formed. The formation of the improved ground layer 9 by the injection of the ground improvement material 18 is performed on all the pipes 7 and 8, and the outer body 5 composed of the improved ground layer sequence is formed on the upper ground between the advanced mine 1 and 2.
[0023]
In addition, the injection | pouring process of the ground improvement material 18 with respect to the ground 6 is performed by the separate process using the injection | pouring pipe | tube 20 as mentioned above after insertion of the pipe bodies 7 and 8, but the ground 6 When the pipe bodies 7 and 8 are inserted, the ground improvement material 18 may be simultaneously injected from the bit 11 or the inside of the pipe bodies 7 and 8 while drilling the ground with the bit 11.
[0024]
After forming the outer body 5 in this way, a large cross-section space part 3 is formed between the advanced mine 1 and 2 by excavating and removing the ground inside (lower) the outer body 23, and a station building is formed in this space part 3. Construction of home 4 etc. In addition, as shown in FIG. 1, an outer body 5 ′ with an improved ground layer formed around the pipe bodies 7 and 8 may also be formed in the lower ground between the advanced mines 1 and 2.
[0025]
FIG. 7 shows a specific embodiment of the present invention, in which the tubular bodies 7 and 8 are inserted into the ground 6 in a state inclined at a certain angle. That is, tube insertion holes 16 are drilled at regular intervals in the length direction on the upper peripheral surface of both advanced mines 1 and 2, and the shafts of the advanced mine 1 and 2 are formed from these tube insertion holes 16. The operation of inserting the tubes 7 and 8 inclined obliquely forward with respect to the direction into the ground and the operation of inserting the inclined tubes 7a and 8a inclined obliquely backward into the ground are performed alternately. It is what.
[0026]
At this time, for example, the insertion hole 16 of the tubular body 7 inserted obliquely forward from one advanced mine 1 and the insertion hole 16 of the tubular body 8a inserted obliquely rearward from the other advanced mine 2 are provided. It is positioned on the upper side and is inserted into the ground from these insertion holes 16 in a straight line, and the tip portion is inserted in the upper ground near the front and rear in the upper ground of the intermediate portion between the advanced mines 1 and 2. One set of pipe bodies 7 and 8a , and the insertion hole 16 of the pipe body 7a inserted diagonally backward from one advanced mine 1 and the pipe body 8 inserted diagonally forward from the other advanced mine 2 The insertion holes 16 are positioned on the lower side so that the insertion holes 16 are opposed to each other in a straight line from the insertion holes 16 in the ground, and the tip portions are overlapped close to each other in the upper ground in the middle portion between the advanced wells 1 and 2. The tube bodies 7a and 8 to be inserted in a combined state are sequentially formed as a set to form tube sets of these sets, The ground improvement material 18 is injected into the ground 6 around the pair of tubular bodies 7, 7a , 8, 8a in the same manner as in the above embodiment to form columnar improved ground layers 9, 9A intersecting in a plane twill pattern. A tunnel outer body 5 is formed.
[0027]
When the columnar improved ground layers 9, 9A intersecting in a plane twill weave are formed in this way, as shown in the figure, several upper improved grounds are placed on the lower improved ground layer 9A. The structure in which the layers 9 are supported in an intersecting manner is ensured, the occurrence of unimproved portions can be reliably eliminated, and a stronger outer shell 5 can be formed. A tunnel T having a large cross section is constructed by excavating the inner ground of the outer body 5 as described above.
[0028]
FIG. 8 shows still another embodiment of the present invention. In the above embodiment, the tubular bodies 7 and 8 inserted facing from the advanced wells 1 and 2 are overlapped with their tip portions in the proximity of each other. By combining them, one improved ground layer 9 is formed. In this embodiment, the pipe body 7b inserted from one advanced mine 1 into the ground and the other advanced mine 2 inserted into the ground. It is those that are the structures that are arranged plane staggered manner alternately by presence regular intervals each other in the front-rear direction and a tube 7c being, improved ground layer 9B injected around ground of one of the tube 7b The tunnel outer body 5 is formed by alternately and continuously improving the ground layer 9B injected into the surrounding ground of the other tubular body 7c . Since other examples and construction modes are the same as those in the above example, description thereof is omitted. According to this embodiment, each improved ground layer can be connected and integrated with a small number.
[0029]
Incidentally, the improved ground layer. 9 to 9B in each example of the above at least two types may be formed of the desired outer body 5 in combination. In any of the above embodiments, the improved ground layer is provided over the entire length of the tubular bodies 7 and 8, but the present invention is not limited to this, and for the purpose of connecting and integrating the tubular bodies to each other, for example, An improved ground layer may be provided only at the intersection of the left and right tubular bodies 7 and 8.
[0030]
【The invention's effect】
As described above, according to the tunnel construction method of the present invention, the step of forming advanced pits parallel to each other at an appropriate interval in the ground, and the arc shape in the ground between these advanced pits from the both advanced pits. A plurality of pipes are inserted at desired intervals in the longitudinal direction of the advanced mine so that at least the tip ends of the pipes overlap or intersect at the middle part of the ground between the advanced mines, and these pipe bodies are formed. Since the pipe is inserted into the ground from both advanced mine shafts, the tunnel can be inserted efficiently and the tunnel shell can be efficiently used. It can be constructed well and the construction length of the pipe body is short, so the insertion work can be done in a short time, and in addition, the pipe body inserted from one advanced mine in the middle part of the ground between advanced mine And inserted from the other advanced mine Since at least the distal portion of the body is intended to polymerize or cross back and forth, it may be applied to large a stable and accurate tunnel enclosures of strength.
[0031]
Furthermore, since the tunnel improvement body with improved ground can be formed around the pipe body by injecting the ground improvement material into the ground through each pipe body, the ground improvement work can be performed smoothly and efficiently. A tunnel with a large cross-section by excavation of the ground inside the body can be built in a short period of time.
[0032]
In addition, since the pipe is inserted into the ground between the advanced mine in an oblique direction with respect to the axial direction of the advanced mine, the pipe inserted diagonally forward into the ground from one advanced mine and the pipe Correspondingly, other improved ground portions are formed on one improved ground portion formed by injecting and injecting ground improvement material from the pipe body obliquely inserted into the ground from the other advanced mine. Tunnel outer bodies overlapped in a planar twill shape can be formed, and an even stronger outer body can be formed by reliably eliminating the occurrence of unmodified parts when constructed in parallel with each other.
[Brief description of the drawings]
FIG. 1 is a simplified longitudinal cross-sectional front view of a built large section tunnel.
FIG. 2 is a longitudinal front view for explaining a method of inserting a pipe body from an advanced mine.
FIG. 3 is a side view of a bending machine disposed in an advanced mine.
FIG. 4 is a longitudinal side view of a distal end portion of a tubular body.
FIG. 5 is a longitudinal side view of a state in which the flexible shaft is removed.
FIG. 6 is a longitudinal side view of a part of a pipe body into which a ground improvement material is injected through the inside.
FIG. 7 is a simplified plan view of an outer body composed of improved ground layers intersecting in a plane twill pattern.
FIG. 8 is a simplified plan view of an outer body composed of improved ground layers arranged in a staggered pattern.
FIG. 9 is a simplified side view showing an insertion state of a steel pipe in a conventional example.
FIG. 10 is a simplified side view of a state where a steel pipe is used as a guide for excavation by a small diameter excavator.
FIG. 11 is a simplified side view of the ground improvement.
[Explanation of symbols]
1, 2 Advanced mine 3 Large section space 5 Tunnel outer body 6 Ground 7, 8 Tube 9 Improved ground layer
16 Tube insertion hole T Large section tunnel

Claims (2)

  Forming advanced mines parallel to each other at an appropriate interval in the ground, and the ground between these advanced mines through pipe insertion holes drilled at predetermined intervals in the length direction in both advanced mines An arcuate tube inside, the tip of the tube from one advanced mine side and the tip of the tube from the other advanced mine side approach each other in the front and back above the middle part of the ground between the advanced mine A step of inserting the ground improvement material into the ground around the pipe body to form a columnar improved ground layer, and a tunnel formed by these improved ground layers A tunnel construction method comprising a step of excavating the ground inside the outer body, and inclined obliquely forward with respect to the axial direction of both advanced wells from the tube insertion holes drilled in both advanced wells. Work to insert the pipe body into the ground, and the pipe inclined diagonally backward Are alternately inserted into the ground, and the pipe inserted diagonally forward from one advanced mine and the pipe inserted diagonally backward from the other advanced mine are on the upper side, A pipe inserted diagonally backward from one advanced mine and a pipe inserted diagonally forward from the other advanced mine are positioned on the lower side to the ground around each pipe. A tunnel construction method characterized by forming a tunnel outer body composed of columnar improved ground layers intersecting in a plane twill weave by injecting a ground improvement material through a tubular body.   Forming advanced mines parallel to each other at an appropriate interval in the ground, and the ground between these advanced mines through pipe insertion holes drilled at predetermined intervals in the length direction in both advanced mines Formed by these improved ground layers, a step of inserting an arc-shaped tubular body into the interior, a step of injecting ground improvement material into the ground around the tubular body through each tubular body to form a columnar improved ground layer, and A tunnel construction method comprising a step of excavating the ground inside the tunnel outer body, wherein the pipe body is inserted into the ground from the one advanced mine side and the other advanced mine side is inserted into the ground. The tip of the improved ground layer injected into the surrounding ground of one tube and the surrounding of the other tube Tunnels made by alternately and continuously improving ground layers injected into the ground Tunnel construction method characterized by forming a Kakukarada.

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