JP2005036547A - Shield tunneling method, shield boring machine and widening segment using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield tunneling method capable of carrying out construction work of a standard part in parallel with construction work of a widening part and efficiently carrying out work, a shield boring machine and a widening segment 22. <P>SOLUTION: The shield boring machine 1 forming a lining body 2 on a bedrock by widening a cross section of a partial section includes a first cutter 11 put on the front end and excavating a standard cross section, a second cutter 14 put on in an expansible manner in the radial direction of the standard cross section and excavating part necessary to widen and a launching instrument pushing the widening segment 22 necessary for placing it to the excavated widening part in the direction of widening. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shield method for excavating by widening a cross section of a part of a section.

  Conventionally, tunnel construction by the shield method has been frequently used, and in recent years, with the diversification of its applications, it has been demanded that the cross-sectional shape of a part of the tunnel is wider than the main tunnel. In response to such a demand, for example, a construction method has been used in which a main tunnel is constructed, a segment is removed after ground improvement from the ground, and a part of the tunnel is widened by widening it from the pit. In this shield method, it is necessary to occupy the ground part for a certain period in order to cut the widened part from the ground part.

However, with the recent urbanization, it is often difficult to occupy the above-ground part depending on the location. Conventionally, in view of such a problem, a shield method that can be constructed only in the underground portion has been considered. Examples of such a shield construction method include an expansion shield construction method and a NATM construction method in which a main line tunnel is constructed and then a segment of the widened portion once assembled is removed for construction. However, in the conventional construction method, the excavation work by the shield machine and the excavation work of the widened portion are performed separately, which is inefficient.
Japanese Examined Patent Publication No. 3-41637 Japanese Patent Publication No. 5-20556

  The present invention has been made in view of such a problem, and can perform the construction of the standard part and the construction of the widened part in parallel, and can perform the work efficiently. And providing a widened segment is a technical problem.

  That is, the present invention uses a shield machine having a first cutter for excavating a standard cross section and an extendable second cutter for excavating a portion widened with respect to the standard cross section. Is a shield method that forms a lining body in a natural mountain by widening, and digging with the first cutter to the portion to be widened, assembling the segments to form a lining body of a standard cross section, The step of extending the second cutter to excavate the portion to be widened, and assembling the widened segment to be disposed in the widened portion so as to be stretchable in the widening direction of the standard cross section, the covering body of the widened portion is The step of forming within the standard cross section, the step of filling the excavated widening portion with a filler that holds the natural ground, and the extrusion of the widening segment into the widening portion while allowing the filler to flow into the lining body. And that step a shield tunneling, characterized in that it comprises a.

  The shield construction method according to the present invention excavates a standard section with a first cutter and excavates a portion to be widened with a second cutter while forming a covering body with the standard section. Since the widened segment formed in the standard cross section can be extended in the radial direction, the widened portion can be constructed by extruding the widened segment to the portion to be widened. That is, it is possible to easily widen the cross section of a part of the section and construct the lining body.

  In the present invention, since the excavated portion to be widened is filled with the filler, it is possible to stabilize the excavated ground. This filler stabilizes the natural ground from the excavation of the widened portion to the construction of the lining body, and it is necessary to flow into the lining body when placing the widening segment. Therefore, the filler needs a certain fluidity so that it can smoothly flow into the lining body. However, if the fluidity is too high, the natural ground cannot be sufficiently stabilized, so that certain plasticity is also required. Furthermore, the filler is required to be a material that is difficult to mix with the muddy water at the time of excavation and the backfill material of the standard cross section or a method that is difficult to mix. From this point of view, it is desirable that the filler and the filling method are variously studied together with the widened segment structure and the like in consideration of various conditions such as soil conditions and groundwater pressure. For example, the following can be illustrated.

  First, a plastic fluidizing material mainly composed of bentonite, water glass, cement, or the like can be given. As a filling method of this filler, after excavating a portion to be widened, it is directly filled from the rear end portion of the shield machine and gelled. It is desirable that the time (gel time) until a certain plasticity is obtained is appropriately adjusted according to the capability of the seal machine.

  Further, it is desirable to fill the filler every time a certain section is excavated, and in many cases, the filler is excavated by the second cutter in the direction of the excavation tip. If the filler is directly filled in such a case, it may be mixed with the muddy water generated by the excavation. For this reason, when the plastic fluidizing material is used as a filler, it is desirable to take measures such as providing a blocking wall at the rear end of the second cutter in the excavation direction. And when making it flow in into a lining body, the inflow port which makes a filler flow in beforehand is provided in the back surface of the widening segment, and what is necessary is just to let it flow in from this inflow port.

  Next, for example, a filler having high fluidity such as water can be used. Such a filler having high fluidity is not suitable because it is mixed with mud water or the like when directly filling the excavated portion like the plastic fluidity material described above. Therefore, when using a filler with high fluidity, it is desirable to attach a bag to the back of the widened segment in advance and fill the bag with the filler. In the filling method, first, a bag is previously attached to the back surface of the widened segment. And at the time of widening excavation by a shield machine, the ground is once held with muddy water. Next, when the widening segment comes out from the rear end of the shield machine, the bag is filled with pressure applied to the filler, and the ground is held. At the time of widening, the widening segment is pushed out, and at the same time, the filler in the bag is discharged by a pump or the like. In addition, after extruding at the widening segment, the bag is filled with a backfill material made of cement or the like generally used.

  In addition, polystyrene foam may be used as the filler. Since the expanded polystyrene has a certain strength, it can sufficiently stabilize the natural ground. When injecting the filler into the lining body, heat the foam by placing a heating wire on the back of the segment, or add the solvent containing limonene to the foamed polystyrene to dissolve the foam and flow into the lining body. You can do it.

Next, the first cutter and the second cutter will be described in detail. Said 1st cutter is a cutter which excavates a standard cross section, and is normally mounted | worn with the front-end | tip of a shield machine. On the other hand, the second cutter can be extended with respect to the radial direction of the standard cross section and excavates only the widened portion. Therefore, it is desirable to provide the first cutter and the second cutter independently, and it is preferable to provide the second cutter on the outer peripheral surface of the shield machine. As a structure of this 2nd cutter, the arm type excavator which combined two rotary cutters is mentioned, for example. It is desirable that this second cutter can be extended in the radial direction and the circumferential direction in the standard cross section. By combining the extension in the radial direction and the circumferential direction, it is possible to excavate the minimum space necessary for widening. It becomes. Furthermore, since the second cutter excavates only the widened portion while forming the lining body when the excavation is stopped, it is desirable that the second cutter is stored in the shield excavator when excavating the standard section.

  Since the widened segment can be extended in the radial direction of the standard cross section, after being formed in the standard cross section, it can be extruded in the direction to be widened as necessary, and the widened portion can be easily constructed. is there. That is, the widened segment can be constructed to serve as both the standard cross section and the widened portion. Therefore, it is not necessary to provide a segment for forming a newly widened portion, and not only the efficiency but also the economic efficiency can be improved.

  Further, the present invention is a shield excavator that widens the cross section of a part of the section and forms a lining body in a natural ground, the first cutter that is attached to the tip and excavates the standard cross section, and the standard cross section A second cutter for excavating a portion to be widened, and an extruding device for extruding a widened segment to be arranged in the widened portion excavated in the radial direction. It is a shield machine that is characterized by.

  With the above configuration, the shield machine according to the present invention can excavate a standard cross section with the first cutter, and excavate a portion to be widened with the second cutter while forming a covering body with the standard cross section. The widened segment that forms the standard cross section can be extended in the radial direction, and is equipped with an extrusion device that pushes the widened segment in the radial direction. I can do it. That is, it is possible to easily widen the cross section of a part of the section and construct the lining body.

  In addition, the shield machine according to the present invention includes a filling material filling device that holds a ground portion of the portion widened by the second cutter, and fills the widening portion excavated by the second cutter. Then, it is desirable to arrange the widened segment in the portion to be widened while allowing the filler to flow into the lining body. By filling the widened portion excavated with the filler, it is possible to construct the widened portion while stabilizing the natural ground with the filler.

  Further, the widening segment used in the shield method or shield machine can be extended in the radial direction of the standard cross section, and is combined with the adjacent segment to form an outer shape that is substantially the same shape as the standard cross section and is extruded in the radial direction. By doing so, it is desirable that a plurality of inflow ports are provided in the widened portion and for allowing the filler to flow into the covering body. By providing a plurality of the inflow ports, it is possible to arrange the widened segments while allowing the filler to easily flow into the covering body.

  In addition, it is desirable that the widened segment is provided with a water stop measure from the viewpoint of preventing water leakage into the lining body to be constructed. For example, the surface of the widened segment includes a waterproof seal, a special waterproofing agent compress, and a water stop measure such as mounting a waterproof bolt in the hole portion of the inlet or the like.

  As described above, according to the shield method, the shield machine and the widening segment used for them according to the present invention, the construction of the standard part and the construction of the widening part can be performed in parallel, and the work can be performed efficiently. it can. In addition, there is no need to perform an auxiliary method such as ground improvement which has been conventionally performed. Therefore, it is possible to easily carry out construction even in places where the above-ground part cannot be occupied, places where underground reserves are congested, places with great depths, etc., and there are no restrictions on the places, which is preferable.

Furthermore, since the 2nd cutter which excavates the part to widen can extend | extract in the radial direction of a standard cross section, since this can excavate the minimum space required for widening, the amount of excavation soil can be decreased. In addition, it is possible to stabilize the natural ground at an early stage by filling the excavated widening portion with a filler, and the method can be selected according to natural ground conditions and the like.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a shield machine used in the present embodiment, and FIGS. 2 to 5 are explanatory diagrams of tunnel excavation processes according to the present embodiment. In the present embodiment, a standard-type tunnel is constructed to the X position shown in the figure, and the tunnel is constructed by widening downward to the X-X ′ position.

  The shield machine 1 used in the present embodiment has a cylindrical shape, a cutter head 11 as a first cutter for excavating a standard cross section at the tip, a skin plate 12 as an outer shell, and a skin plate 12 provided on the skin plate 12. A slit door 13 that can be opened and closed, an arm excavator 14 as a second cutter that can be extended from the slit door 13 in the outer circumferential direction and the radial direction, and formed on the skin plate 12 adjacent to the slit door 13. A filling device (not shown) of the filled material 16, an injection port 15 of this filling device, an erector (not shown) arranged inside the shield machine 1 and assembling the segment 21 to construct the tunnel 2. And an extrusion jack 17 as an extrusion device for extruding the segment 21 to the portion to be widened.

  First, in the state where a tunnel having a standard cross section is constructed, only the cutter head 11 is driven. Then, while assembling the segment 21 with the erector, the tunnel 2 having a standard cross section is dug. At this time, the arm type excavator 14 is housed in the shield machine 1 and the slit door 13 is closed (see FIG. 2). When the slit door 13 is located at X, which is the starting point of the widened portion, the slit door 13 is opened, and the arm type excavator 14 is extended in the radial direction of the shield machine 1.

  The arm type excavator 14 is a muddy water type excavation method and includes two rotary cutters 14a for rotary excavation and an arm 14b for moving the rotary cutter 14a. The rotary cutter 14a has a large number of cutter bits projecting on the outer periphery, and the adjacent rings rotate so as to excavate a natural ground and flow the excavated earth and mud into the tunnel. . The arm 14b has a mechanism for expanding and contracting the shield machine 1 in the radial direction and a mechanism for turning the shield machine in the circumferential direction. By combining these mechanisms, the minimum space required for widening is provided. Can be excavated (see FIG. 7).

  A standard cross section is excavated in a state where the arm type excavator 14 is stored in the shield machine 1 by the cutter head 11, and a portion widened by the arm type excavator 14 is excavated while assembling the segment 21. Each time the segment 21 is assembled to form one ring, the filler 16 is filled into the space provided between the excavated widened portion and the outer peripheral surface of the shield machine 1. By filling the filler 16, it is possible to hold the natural ground and reduce the frictional resistance with the natural ground.

  On the other hand, at the rear end portion of the shield machine 1, a segment 21 is assembled by an erector as the shield machine 1 is propelled to construct a ring. 8 and 9 show the cross-sectional shape of the ring disposed in the widened portion. FIG. 8 shows a state before widening, and FIG. 9 shows a state when widening. In this ring, a plurality of segments 21 are connected and integrated by bolts and nuts. The widened segment 22 to be disposed in the widened portion has a long surface 22a that contacts the adjacent segment 21, and two bolt holes are formed in this surface 22a.

Moreover, the widening segment 22 arrange | positioned at the both ends of the part to be widened, in other words, the widening segment 22 arrange | positioned at X surface and X 'surface has the end wall 22b, and when it is widened, It is formed to prevent water leakage (see FIG. 10). That is, the widened segment 22 forms the same outer shape as the standard cross section before widening, and a widened structure can be constructed by being extruded in the radial direction.

  Further, the widening segment 22 is provided with an inlet 22c for allowing the filler 16 to flow into the tunnel 2 on the back surface constituting the outer peripheral surface of the ring. The inlet 22c only needs to be opened only when the filler 16 is allowed to flow into the tunnel 2, so that it is desirable that the inlet 22c be configured to be easily opened and closed. Further, an extrusion jack 17 for extruding the widened segment 22 and a shape holding column 18 for holding the shape in the ring are arranged in the ring. In the present embodiment, the extrusion jack 17 and the shape retaining column 18 are provided separately, but it is also possible to form a cart that combines the two functions as one system. By using this cart, it is possible to improve the workability and quality of widening.

  And when excavation of the shield machine 1 progresses and the widened segment 22 is pushed out to the portion to be widened, the bolts and nuts connected to the adjacent segments 21 are unfastened and provided on the surface of the widened segment. The inflow port 22c is opened. And using the said extrusion jack 17, it extrudes to a wide part while sliding with the contact surface 22a with the adjacent segment 21. FIG. At this time, the filler 16 filled in advance in the excavated widened portion flows into the tunnel 2 from the inflow port 22c. In the present embodiment, the widened segment 22 is pushed out into the widened portion every three rings (see FIG. 4).

  Then, after the widened segment 22 is pushed out to the position to be arranged, it is connected to the adjacent segment 21. In addition, the inlet 22c is sealed in order to prevent water leakage from the natural ground from flowing into the ring. At this time, it is desirable to improve the water-stopping property. In this embodiment, a rubber washer is attached to a bolt that closes the inflow port 22c.

  This process is repeated to construct the tunnel 2 in the portion to be widened. When the arm excavator 14 excavates to the position X ′, the excavation of the arm excavator 14 is stopped and the arm excavator 14 is stored in the slit door 13 (see FIG. 5). And each ring excavation is carried out only with the cutter head 11, and the tunnel 2 main body is constructed (see FIG. 6).

  As described above, according to the present embodiment, the construction of the standard part and the construction of the widened part can be performed in parallel, and the work can be performed efficiently. In addition, since the second cutter for excavating the widening portion can be extended in the radial direction of the standard section, the minimum space necessary for widening can be excavated, so the amount of excavated soil could be reduced. In addition, the ground was able to be stabilized at an early stage by filling the excavated widening part with a filler.

  FIG. 11 is a view showing a filling method in a different mode from the above embodiment. Embodiments of other portions are the same as those of the above embodiment. In the first embodiment, a bag 22d filled with a filler in advance is attached to the back surface of the widened segment 22 (a). First, after excavating the widening portion, the filling material 16 is filled into the bag 22d (b). Then, the filler is caused to flow into the tunnel 2 as the widened segment 22 is extruded. Next, a normal backfill material is reinjected into the bag from which the filler 16 has been discharged (c).

FIG. 12 is a view showing a filling method in a mode different from the above embodiment, as in the case of Example 1. Embodiments of other portions are the same as those of the above embodiment. In the present Example 2, a polystyrene foam is used as a filler, and the excavated cross section is directly filled. First, after excavating the widening portion, the foamed mortar is filled. This filled foamed mortar is cured and expanded polystyrene 16a.
(A). When extruding the widened segment 22, the solvent (limonene) 16b is sprayed onto the expanded polystyrene 16a to dissolve the expanded polystyrene 16a (b). Then, the widened segment 22 is disposed in the widened portion while the molten polystyrene 16a flows into the tunnel 2 (c).

  In this example, a solvent was used as a method for dissolving the expanded polystyrene, but a heating wire for heating the back surface of the widened segment 22 was previously placed inside the widened segment 22 and heated with a heated wire to melt the expanded polystyrene. Also good.

It is a perspective view of the shield machine which concerns on this Embodiment. It is explanatory drawing of the excavation process of the tunnel which concerns on this Embodiment. It is explanatory drawing of the excavation process of the tunnel which concerns on this Embodiment. It is explanatory drawing of the excavation process of the tunnel which concerns on this Embodiment. It is explanatory drawing of the excavation process of the tunnel which concerns on this Embodiment. It is explanatory drawing of the excavation process of the tunnel which concerns on this Embodiment. It is an explanation schematic diagram of an arm type excavator. It is sectional drawing of the ring which assembled the segment (before extrusion). It is sectional drawing of the ring which assembled the segment (after extrusion). It is a perspective view of a widening segment. It is explanatory drawing of the filling method of the filler which concerns on Example 1. FIG. It is explanatory drawing of the filling method of the filler which concerns on Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield machine 11 Cutter head 12 Skin plate 13 Slit door 14 Arm type excavator 14a Rotary cutter 14b Arm 15 Inlet 16 Filler 16a Styrofoam 16b Solvent 17 Extrusion jack 18 Shape maintenance pillar 2 Tunnel 21 Segment 22 Widening segment 22b Wife Wall 22c Inlet 22d Bag

Claims (4)

Using a shield cutter with a first cutter that excavates a standard section and a stretchable second cutter that excavates a portion that widens relative to this standard section, the section of a section is expanded and a natural ground A shield method for forming a lining body on
While excavating with the first cutter to the part to be widened, assembling the segments to form a standard cross-section lining body,
Extending the second cutter to excavate a portion to be widened;
Assembling a widening segment to be arranged in the widening portion so as to be stretchable in the widening direction, and forming a covering body of the widening portion in the standard cross section; and
Filling the excavated widening portion with a filler that holds the natural ground; and
And a step of extruding the widened segment to a portion to be widened while allowing the filler to flow into the covering body. A shield machine that widens the cross section of some sections and forms a lining body in the natural ground,
A first cutter attached to the tip and drilling a standard cross section;
A second cutter that is mounted so as to be stretchable in the radial direction of the standard cross section and excavates a portion to be widened;
A shield machine, comprising: an extruding device that extrudes a widening segment to be disposed in a widened portion excavated in the widening direction. A filling device for filling material that holds the natural ground of the portion widened by the second cutter,
The filling portion is filled in the widening portion excavated by the second cutter, and then the widening segment is disposed in the widening portion while the filling material is allowed to flow into the lining body. Shield machine. A widening segment used for the shield construction method according to claim 1 or the shield machine according to claim 3,
The filler can be extended in the widening direction of the standard cross section, is combined with adjacent segments to form an outer shape that is substantially the same shape as the standard cross section, and is arranged in the widened portion by being extruded in the radial direction, and the filler A widening segment characterized in that a plurality of inlets are provided for injecting into the lining body.

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