JP7249925B2 - Construction method of tunnel curved part in shield construction method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a construction method for tunnel curved sections in a shield construction method, and more particularly to a technique for constructing tunnel curved sections by annularly assembling hexagonal segments.

A shield tunneling machine excavates the natural ground by rotating a cutter disk pressed against the face while stabilizing the face, and builds a tunnel by assembling segments in a circular shape around the inner circumference of the excavated hole. Equipment.

The equipment body of the shield machine has a front body and a rear body. The front barrel is articulably connected to the front end of the rear barrel. Inside the device body, a plurality of folding jacks are arranged between the front body and the rear body, and a plurality of propulsion jacks are arranged in the rear body along the circumferential direction of the device body. In general, the posture of the shield machine is controlled by selecting the folding jack or the propulsion jack.

When constructing a curved tunnel section with a shield machine, the segment assembly is bent in the desired direction using segments with tapered front and rear joints located in front and back of the excavation hole. Build a lining.

As for construction of a curved tunnel section by a shield tunneling machine, for example, one described in Patent Document 1 is known.

Japanese Patent Laid-Open No. 2005-330749

The segments have hexagonal segments with oppositely formed long side joints and V-shaped slanted joints protruding on both sides of the long side joints. Hexagonal segments are assembled in a staggered manner with the long side joints facing the front and back of the excavation to construct a tunnel that covers the inner circumference of the excavation. And when constructing a tunnel curved part using this hexagonal segment, the hexagonal segment for curved parts which the long-side joint part which opposes became tapered in planar view is used.

Here, when tapered hexagonal segments are used, since the driving jacks and the end faces of the hexagonal segments (pressing surfaces by the driving jacks) are not orthogonal, a force couple is generated in the circumferential direction.

In the hexagonal segment, convex portions near the face and trapezoidal concave portions recessed from the convex portion by half the width of the hexagonal segment are alternately formed along the circumferential direction (unevenness formation). The hexagonal segments that form the protrusions weaken the restraining force in the circumferential direction. In addition, the length difference between the strokes of the plurality of propelling jacks that press the end faces of the hexagonal segments that are unevenly formed increases, and the balance deteriorates.

Therefore, when pushing the end faces of the tapered hexagonal segments assembled in a zigzag pattern to advance the shield machine, rolling is more likely to occur than in the case of pushing ordinary rectangular segments.

The present invention has been made in view of the above-mentioned technical background, and provides a technology capable of preventing rolling of a shield machine when constructing a curved portion of a tunnel using tapered hexagonal segments. intended to

In order to solve the above-mentioned problems, the method for constructing a curved tunnel section according to claim 1 of the present invention comprises: a forward section having a cutter head; and a plurality of center-folding jacks arranged in the circumferential direction between the front and rear torso sections to connect the front and rear torso sections in a bendable manner. long side joints that are formed to face each other and are tapered in a plan view, and V-shaped inclined joints that protrude from both sides of the long side joints. A tunnel curved section construction method in a shield construction method in which the long side joints of the hexagonal segments are assembled in a zigzag manner toward the front and back of the excavated hole to construct the curved section of the tunnel covering the inner peripheral surface of the excavated hole. The face sides of the linings composed of the hexagonal segments assembled in an annular shape are pressed with the same pressing force by all the propulsion jacks to take reaction force, and the shield excavation is performed by the folding jacks. characterized by controlling the propelling direction of the aircraft.

According to the present invention, when a lining body composed of tapered hexagonal segments is pressed by a propulsion jack, the couple of forces generated in the respective hexagonal segments are canceled out. In this way, when the end faces of the tapered hexagonal segments assembled in a zigzag manner are pressed by the propeller jacks, the force couple is canceled between the segments. It becomes possible to prevent rolling of the shield machine when constructing the part.

FIG. 1 is a configuration diagram showing the inside of a shield machine used in a method for constructing a curved tunnel portion in a shield construction method, which is an embodiment of the invention, seen through from the side. FIG. 4 is a plan view of a hexagonal segment used for construction of a straight section of a tunnel; Figure 3 is a front view of the hexagonal segment of Figure 2; Figure 3 is a side view of the hexagonal segment of Figure 2; 3 is a side view of a ring-shaped lining constructed by assembling the hexagonal segments of FIG. 2; FIG. (a) is a plan view showing an example of a tapered hexagonal segment used for constructing a curved portion of a tunnel, and (b) is a cross-sectional view taken along line xx in (a). (a) is a plan view showing another example of a tapered hexagonal segment used for constructing a curved portion of a tunnel, and (b) is a cross-sectional view taken along line yy of (a). FIG. 4 is a side view of a ring-shaped lining constructed by assembling tapered hexagonal segments; It is explanatory drawing which shows the force couple which generate|occur|produces when a taper-shaped hexagonal segment is pressed by a propulsion jack. FIG. 10 is an explanatory diagram showing a couple of forces when the ring-shaped lining body constructed by assembling tapered hexagonal segments is pressed by a propelling jack in an unfolded state.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment as an example of the present invention will be described in detail below with reference to the drawings. In the drawings for describing the embodiments, in principle, the same components are denoted by the same reference numerals, and repeated description thereof will be omitted.

FIG. 1 is a side view of the inside of a shield machine used in a method for constructing a curved tunnel section in a shield construction method, which is an embodiment of the invention.

As shown in FIG. 1, the shield excavator 1 of the present embodiment generates mud having water impermeability and plastic fluidity by injecting and kneading additives into the earth and sand excavated by the cutter head 2. Then, the chamber between the cutter head 2 and the equipment body 3 is filled with the mud and excavated to generate mud pressure, and the excavation hole is constructed in a state where the mud pressure is opposed to the earth pressure of the face. It is a device that

The cutter head 2 is a member for excavating the face of the ground, and is installed on the front surface of the device main body 3 so as to be rotatable along the circumferential direction of the cutter head 2 . This cutter head 2 is equipped with various types of bits 4 for excavating the face.

The device main body 3 includes a front body portion 3a having the cutter head 2 and a rear body portion 3b behind it. The front body part 3 a and the rear body part 3 b are formed of, for example, cylindrical steel plates, and are members that form the outer shape of the device body 3 and form a hollow space inside the device body 3 .

A partition wall 7 is provided on the front side of the front section 3a at a position recessed inward from the front surface of the device body 3a to divide the hollow space inside the device body 3 into a face side and a machine side. A chamber 6 is provided on the face side of the partition wall 7 , that is, between the cutter head 2 and the partition wall 7 . Further, an additive injection part 5b, a cutter driving body 8, a folding jack 9a, a propelling jack 9b, a screw conveyor 10, an erector 11, and the like are provided inside the partition wall 7. As shown in FIG.

Here, the additive material injection part 5b is a device for injecting the additive material toward the outer periphery of the device main body 3 and the inside of the chamber 6. As shown in FIG. The cutter driving body 8 is a driving source that rotates the cutter head 2 . The center-folding jack 9a is a device that connects the front body portion 3a and the rear body portion 3b in a bendable manner, and controls the direction in which the shield machine 1 is propelled. The propulsion jack 9b is a device that generates a propulsive force for moving the shield machine 1 forward by receiving a reaction force from the segment SG installed behind the machine body 3. As shown in FIG. A plurality of them are arranged side by side along the circumferential direction of the shield machine 1 on the rear body portion 3b of the shield machine. The screw conveyor 10 is a device for discharging earth and sand taken in the chamber 6 to the outside of the machine. The erector 11 is a device for gripping the segments and assembling them into an annular lining.

Now, in the present embodiment, the shield machine 1 having the above configuration is used, and the hexagonal segments are assembled in a staggered manner to form an annular lining body, which is continuously connected to cover the inner peripheral surface of the excavation hole. A tunnel is built.

Here, the hexagonal segments used for constructing the straight portion of the tunnel will be described with reference to FIGS. 2 to 4. FIG.

As shown in these drawings, the hexagonal segment SG is curved in the circumferential direction of the tunnel and formed into a planar hexagonal shape, and two long side joints formed facing each other and parallel in plan view. It has a portion J1 and a V-shaped inclined joint J2 projecting from both sides of the long side joint J1. Further, a gripping hole H1 into which an anchor (not shown) is inserted when gripped by the erector 11 is formed in the central portion of the inner surface.

In this hexagonal segment SG, a sheath tube T through which a joint bolt between the oblique sides penetrates is embedded parallel to one inclined surface of the inclined joint J2, and a joint bolt between the oblique sides is embedded in one of the long-side joints J1. A tightening hole H2 for tightening is formed continuously with the sheath tube T. Also, an insert anchor F1 is embedded in parallel with the other inclined surface of the inclined joint J2 to be screwed with a joint bolt between hypotenuses passing through the sheath tube T of the other hexagonal segment SG to be joined. Furthermore, a suspension insert F2 used when suspending the hexagonal segment SG is embedded from the other long side joint J1 toward the inside.

On the outer peripheral surface of the hexagonal segment SG, there are recessed inter-ring sockets R1 and protruding inter-ring plugs R2 as portions for aligning with other hexagonal segments SG by fitting them in recesses and projections. formed.

Although the hexagonal segment SG is made of reinforced concrete in this embodiment, it may be made of steel.

Such hexagonal segments SG are assembled in a staggered manner in the circumferential direction of the excavation to construct the ring-shaped lining body B shown in FIG. In the lining body B, the long-side joints J1 of the hexagonal segments SG are arranged to face the front and back of the excavation hole (that is, the face side and the tunnel mouth side), and the inclination of the hexagonal segments SG located in the front and back direction By alternately connecting the joints J2, a convex portion near the face and a trapezoidal concave portion recessed from the convex portion by half the width of the hexagonal segment SG are alternately formed along the circumferential direction ( Concavo-convex formation). Then, the front half of the next hexagonal segment SG is axially inserted and fitted into the formed recess.

When assembling the hexagonal segments SG, the face side of the lining body B made up of the already assembled hexagonal segments is pressed by the propelling jack 9b to take reaction force, and the shield machine 1 is moved to the hexagonal shape. An assembly space is formed by moving forward by the width of the segment SG. Further, the driving direction of the shield machine 1 is controlled by the folding jack 9a.

Now, a tunnel has a straight portion with no bends and a curved portion that bends in vertical and horizontal directions. When constructing a curved portion of a tunnel using hexagonal segments, hexagonal segments SG for curved portions having tapered long-side joints J1 are used.

An example of a hexagonal segment for a curve is shown in FIGS. 6 and 7. FIG. In any hexagonal segment SG, the long-side joint J1 formed to face each other has a tapered shape in plan view, but in the hexagonal segment SG shown in FIG. The straight line L is inclined with respect to the long-side joint J1 on the portal side (see FIG. 6(a)), and the hexagonal segment SG is slightly bent at the straight line L (see FIG. 6(b)). The straight line L and the face-side long-side joint J1 are parallel to each other.

In addition, in the hexagonal segment SG shown in FIG. 7, the long-side joint J1 on the portal side and the long-side joint J1 on the face side are tapered, but unlike the hexagonal segment SG shown in FIG. , are not bent at the straight line L connecting the vertices of the inclined joints J2 on both sides (see FIG. 7(a)). In addition, the end surface of the long side joint J1 on the face side is slightly inclined with respect to the front and back surfaces (see FIG. 7(b)).

A curved tunnel constructed using such hexagonal segments SG is shown in FIG.

Here, as shown in FIG. 9, when a tapered hexagonal segment SG is used, the pressing direction D of the driving jack 9b and the end surface of the long side joint J1 of the hexagonal segment SG on the face side (that is, the driving jack) 9b) are not perpendicular to each other, a force couple F is generated in the circumferential direction of the tunnel on the hexagonal segment SG, and a force couple F' in the opposite direction to the force couple F is generated on the propulsion jack 9b. will occur.

As described above, in the hexagonal segment SG, the convex portions and the concave portions are formed alternately along the circumferential direction, so that the hexagonal segments forming the convex portions have a weaker restraining force in the circumferential direction. In addition, since the hexagonal segments are uneven in the circumferential direction, the difference in stroke length between the plurality of propelling jacks that press the end faces of the hexagonal segments increases, resulting in poor balance.

Therefore, the shield machine 1 moving forward by pressing the hexagonal segment SG is likely to roll under the influence of the force couple F' of the propulsion jacks 9b.

Therefore, in the present embodiment, when the face side of the lining body B composed of tapered hexagonal segments SG assembled in an annular shape is pressed by the driving jacks 9b, the pressing forces of all the driving jacks 9b are mutual. are adjusted to be the same. Then, the hexagonal segment SG is pushed so that all the jacks 9b have the same pressing force, and the shield machine 1 is moved forward while receiving the reaction force. is controlling

Here, FIG. 10 shows a state in which the face side of the lining B composed of tapered hexagonal segments SG assembled in an annular shape is pressed by the propelling jack 9b. The hatched hexagonal segment SG in FIG. 10 is the tapered hexagonal segment SG used in the curved portion of the tunnel.

As shown in FIG. 10, when the lining body B composed of tapered hexagonal segments SG is pressed by the propelling jack 9b, the couple of forces generated in the respective hexagonal segments SG are canceled out.

That is, the force couple Fa1 generated in the hexagonal segment SG located at the top and the force couple Fa2 generated in the hexagonal segment SG located at the bottom cancel each other in opposite directions. In addition, the force couple Fb1 and the force couple Fb2 respectively generated in the two adjacent hexagonal segments SG forming one side face are canceled in opposite directions. Then, the force couple Fc1 and the force couple Fc2 respectively generated in the two adjacent hexagonal segments SG forming the other side face are canceled in opposite directions.

In this way, when the end faces of the tapered hexagonal segments SG assembled in a zigzag manner are pressed by the propelling jack 9b, the force couple is canceled between the segments SG. It is possible to prevent the shield machine 1 from rolling when constructing a curved section.

As described above, the invention made by the present inventor was specifically described based on the embodiment, but the embodiment disclosed in this specification is an example in all respects, and is limited to the technology disclosed. not a thing That is, the technical scope of the present invention should not be construed in a restrictive manner based on the description of the above embodiments, but should be construed according to the description of the scope of claims. All modifications are included as long as they do not deviate from the description technology and equivalent technology and the gist of the claims.

For example, the fact that all of the thrust jacks 9b press the end surfaces of the tapered hexagonal segments SG with the same pressing force does not mean that they are exactly the same, and it is sufficient if they are substantially the same.

In the above description, the case where the present invention is applied to a mud pressure type shield machine has been described, but the present invention is not limited to this. The mud is pumped by a mud pump, and the pressure of the mud in the mud chamber is adjusted to match the earth pressure of the face and the groundwater pressure. It can also be applied to other shield machines such as a mud type shield machine that forms.

1 Shield Machine 2 Cutter Head 3 Equipment Body 3a Front Body 3b Rear Body 6 Chamber 7 Bulkhead 9a Folding Jack 9b Propulsion Jack 11 Erector B Linings F, F', Fa1, Fa2, Fb1, Fb2, Fc1, Fc2 Couple J1 Long-side joint J2 Inclined joint SG Hexagonal segment

Claims (1)

a forebody having a cutter head, a rear barrel having a plurality of propulsion jacks circumferentially disposed at the rearward end of the forebody, and a circumference between the forebody and the aft barrel. Using a shield machine having a bending jack that is arranged in a plurality of directions and connects the front body and the rear body in a bendable manner,
The long sides of the hexagonal segment are provided with long side joints formed to face each other and tapered in plan view and V-shaped inclined joints protruding from both sides of the long side joints. A tunnel curved section construction method in a shield construction method in which joints are assembled in a zigzag manner toward the front and back of an excavation to construct a curved section of a tunnel covering the inner peripheral surface of the excavation,
While the face sides of the lining body composed of the hexagonal segments assembled in an annular shape are mutually pressed with the same pressing force by all of the propulsion jacks to take reaction force, the bending jacks are used to move the shield machine. to control the direction of propulsion,
A method for constructing a tunnel curved portion in a shield construction method characterized by:

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