JP6307135B2 - Open shield method - Google Patents

Description

The present invention, water supply and sewerage, joint groove, but about the open shield construction method of applying an underground structures attached underpasses or the like, such as telegraph, telephone etc. City.

The open shield construction method is a rational construction method that takes advantage of the advantages of the open cut construction method (open cut construction method) and the shield construction method. The outline is shown in FIG. The open shield machine 1 has front, rear and top surfaces comprising left and right side wall plates 1a and a bottom plate 1b connected to the side wall plates 1a. The front end of the side wall plate 1a and the bottom plate 1b is formed as a blade edge 11. In addition, a shield jack (propulsion jack) 2 is arranged in the vertical direction near the center or near the rear end of the side wall plate 1a. In the figure, 3 indicates a partition wall.
JP 2003-41896 A

  Although illustration is omitted, the open shield machine 1 divides the machine body into a plurality of parts in the front-rear direction, and the front end of the rear machine body as the tail machine is inserted into the rear end of the front machine body as the front machine so It may be bent at the part.

  The front machine mainly performs excavation, and has a front end and an upper surface as open surfaces. Inside the machine body, middle folding jacks are arranged rearward and rearward and arranged in a plurality of stages. On the other hand, the tail machine installs the concrete box 4, and the propulsion jacks (shield jacks) 2 are arranged in the upper and lower stages in the machine body, facing the front and the rear. Yes.

  The open shield construction method constructed using such an open shield machine 1 installs this open shield machine 1 in the start mine, extends the shield jack 2 of the open shield machine 1 and reacts against the reaction wall in the start mine. The open shield machine 1 is moved forward, the first concrete box 4 forming the underground structure is suspended from above, and set behind the shield jack 2 that is shrunk in the tail portion 1c of the open shield machine 1 To do. A strut is disposed between the shield jack 2 and the reaction wall to adjust the distance appropriately.

  In addition, the start pit is made up of a retaining wall, and in order to start the open shield machine 1, a part of this retaining wall is mirror-cut. If necessary, the ground is improved at the front part of the starting pit by chemical injection or the like. Sometimes it is left.

  Excavator 9 such as an excavator excavates and removes soil from the front or top surface of open shield machine 1. Simultaneously with or after this earth removal step, the shield jack 2 is extended to advance the open shield machine 1. In the case of this forward process, a press bar 8 made of a frame body made of box steel or mold steel is disposed in front of the concrete box 4, and the open shield machine 1 reacts from the concrete box 4 set rearward. Take.

  Then, the second concrete box 4 is suspended in the tail part 1 c of the open shield machine 1 in front of the first concrete box 4. Thereafter, the same soil removal process, advance process, and setting process of the concrete box 4 are repeated as appropriate, and the concrete boxes 4 are sequentially left in the ground as the open shield machine 1 moves forward. Put backfill 5 on the upper surface of 4.

  When the concrete box 4 is suspended in the tail part 1c of the open shield machine 1, a height adjusting material 7 such as a concrete block is disposed under the concrete box 4, and the concrete part 4 is placed in the tail part 1c. A plastic back-filling injection material 6 is filled in the left and right and lower gaps of the box 4 (primary injection).

  FIG. 23 shows this primary pouring work. A plastic back is formed in the gap between the inner surface of the tail portion 1 c and the outer surface of the concrete box 4 from the inside of the concrete box 4 through the grout hole 12 of the concrete box 4. The injection material 6 a is injected and filled with the injection nozzle 13. The back-filling material 6a is composed of two liquids, liquid A and liquid B. Liquid A is a cement milk form in which early-strength cement, auxiliary material, stabilizer, and water are kneaded. It is a viscous liquid and is used alone.

  Construction is performed on the ground using a dedicated backfilling plant installed on the ground. From the backfilling plant, liquid A is piped to the back of the shield machine using 2B pipe and liquid B is pipe 1B. The two pumped liquids are mixed and injected through a special double pipe attached to the box grout hole.

  Further, as shown in FIG. 24, simultaneously with propulsion, secondary injection is performed by injecting and filling the plastic back-filling injection material 6 b into the tail void (the thickness of the tail bottom plate and the side plate) from the inside of the concrete box 4. This secondary injection is performed by firmly fixing the injection nozzle 13 to the grout hole 12 in the bottom plate portion of the concrete box 4 in the same manner as the primary injection.

  In this way, if the open shield machine 1 reaches the reaching mine, it is removed and the construction is completed.

  In such an open shield construction method, as described above, the concrete box 4 is left in the ground in a column as the open shield machine 1 advances, and the concrete box 4 is suspended in the tail portion 1c of the open shield machine 1. As the open shield machine 1 moves forward, it leaves the tail portion 1c and remains in the ground. The open shield machine 1 takes a reaction force on the concrete box 4 left in the ground in this way. Advance.

  The concrete box 4 is made of reinforced concrete and includes a left side plate 4a, a right side plate 4b, an upper floor plate 4c, and a lower floor plate 4d as shown in FIG.

  The concrete boxes 4 are connected to each other by providing through-holes in the front-rear direction at the corners and connecting them in a column with tightness of PC steel bars such as long bolts.

  Although not shown in the figure, a ring-shaped joint called a collar having a T-shaped cross section is interposed between the concrete boxes 4 and 4 at the front and rear positions, and the front and rear concrete boxes 4 are connected by this collar. There is also.

  When the ground is soft in the open shield method as described above, the concrete box to be laid down may sink and the whole may be inclined or curved.

  The risk is particularly strong when it is required to connect the concrete boxes 4 to each other as a flexible joint as an anti-earthquake measure such as an earthquake or a ground subsidence measure in soft ground.

  An object of the present invention is to provide an open shield method and a concrete box used therefor, which can eliminate the disadvantages of the conventional example and prevent the set-up of the concrete box to be laid down even when the ground is soft.

In order to achieve the above object, the present invention advances the shield machine by excavating and discharging the soil in front of the front or top opening of the open shield machine and extending the propulsion jack to make the concrete box a reaction force. The process and the process of hanging and setting a new concrete box from the upper side behind the propulsion jack shrunk in the tail part of the shield machine are repeated as appropriate, and the concrete boxes are sequentially embedded in tandem, and the concrete box is placed in the tail part. After the body is installed, the primary infusion process that injects and fills the plastic backfill injection material into the gap between the inner surface of the tail part and the outer surface of the box, and the tail void is injected and filled with the plastic backfill injection material as the shield machine advances. In the open shield method that performs secondary injection, which is the work to be performed, the concrete box has irregularities formed on the outer surfaces of the left and right side plates, and back injection of the primary injection It is an Abstract that is joined to a box body in this irregularity in the tail portion of the shield machine, increases the friction of a box body and Urakomi grout.

  According to the present invention, since the concrete box has irregularities formed on the outer surfaces of the left and right side plates, the back-filling material of the primary injection can be joined to the box with these irregularities, and the friction with the box can be increased. As a result, settlement of the laying box can be suppressed.

  As described above, the open shield method of the present invention can prevent the concrete box to be laid down from sinking even when the ground is soft.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal front view showing an embodiment of the open shield method of the present invention, and FIGS. 2 to 4 show a first embodiment of a concrete box.

  The concrete box 4 will be described first. The concrete box 4 is made of reinforced concrete as described above with reference to FIG. 19, and includes the left side plate 4a, the right side plate 4b, the upper floor plate 4c, and the lower floor plate 4d. Is opened as an opening 10, but irregularities are formed on the outer surfaces of the left side plate 4 a and the right side plate 4 b.

  In the present embodiment, the unevenness is formed by alternately arranging horizontal rail-like ridges 16a extending in the front-rear direction of the concrete box 4 and grooves 16b having a rectangular cross section therebetween.

  As shown in FIG. 5, when the height of the horizontal rail-shaped ridge 16a is h, the width is t, and the width of the groove 16b is l, t≈h × √2, l≈t × 1.5. Become.

  This unevenness can be integrally formed when the concrete box 4 is formed into a mold.

  Further, as shown in FIG. 3, the lower surface of the lower floor plate 4d of the concrete box 4 is also formed with irregularities in which the ridges 16a having a rectangular cross section and a groove 16b having a rectangular cross section therebetween are alternately arranged. Also good.

  FIGS. 6-8 shows 2nd Embodiment of an unevenness | corrugation, and the horizontal bar-shaped convex strip 17a and the groove 17b in the meantime were made into the trapezoidal cross section instead of the cross-sectional rectangle.

  9 to 11 show a third embodiment of the unevenness, which is a continuous wave shape of triangular peaks 18a and valleys 18b.

  FIGS. 12-14 shows 4th Embodiment of an unevenness | corrugation, and it was set as the satin 19 as the rough surface by unevenness.

  FIGS. 15 to 17 show a fifth embodiment of irregularities, in which the protrusions are dotted with circular protrusions 20a, and the recesses are between the circular protrusions 20a (outside of the left side plate 4a and the right side plate 4b). Surface).

  As described with reference to FIG. 21, the open shield machine 1 has an opening at the front, rear, and top surfaces including left and right side wall plates 1a and a bottom plate 1b connected to the side wall plates 1a. The front end of 1b is formed as the blade edge 11, and the shield jack 2 is arranged in the vertical direction toward the rear in the center or near the rear end of the side wall plate 1a.

  As shown in FIGS. 18 to 20, the open shield machine 1 used in the present invention has a hook-like projection 14 formed on the rear end of the outer surface of the side wall plate 1 a that forms the tail portion 1 c of the shield machine 1.

  The hook-shaped protrusion 14 is a rectangular bar-shaped member having a tapered tip end surface 14a in the forward direction of the shield machine 1 and is attached to the tail 1c surface of the shield machine 1. Exist.

  Note that the rear end portion of the protrusion 14 may protrude from the rear end of the tail portion 1 c of the shield machine 1.

  As shown in FIG. 21, in the open shield method, excavator 9 such as an excavator excavates and removes soil from the front or upper surface of open shield machine 1, and extends shield jack 2 at the same time or after this earth removal process. Then, the open shield machine 1 is advanced.

  In the case of this forward process, a press bar 8 made of a frame body made of box steel or mold steel is disposed in front of the concrete box 4, and the open shield machine 1 reacts from the concrete box 4 set rearward. Take.

  Then, a new concrete box 4 is suspended in the tail portion 1 c of the open shield machine 1 in front of the existing concrete box 4.

  Thereafter, the same earth removal process, forward process, and concrete box 4 setting process are repeated as appropriate, and the concrete boxes 4 are sequentially left in the ground as the open shield machine 1 moves forward. Put backfill 5 on the upper surface of the body 4.

  When the concrete box 4 is suspended in the tail part 1 c of the open shield machine 1, the back injection material 6 is filled into the left and right gaps of the concrete box 4 in the tail part 1 c.

  In this way, if the open shield machine 1 reaches the reaching mine, it is removed and the construction is completed.

The injection of the back-filling material 6 is performed by a primary pouring work performed in the open shield machine 1 when the concrete box 4 is suspended in the tail portion 1 c of the open shield machine 1, and at the same time as the open shield machine 1 is propelled. This is divided into secondary injections in which injection is performed from the inside of the body 4 to the tail voids (the thickness of the tail bottom plate and the side plate).

  The back injection material 6a of the primary injection work can be joined to the box with the irregularities formed on the outer surfaces of the left side plate 4a and the right side plate 4b, and the friction with the box can be increased.

Incidentally, the uniaxial compressive strength (N / mm ² ) of the backfilling injection materials 6a and 6b is 1 hour strength, ≈0.09, and 28 day strength ≒ 2.1, and the backfilling injection material 6a is uneven. By filling the recesses, it is possible to increase the friction with the box due to the backfilling injection material.

  In addition, as shown in FIG. 3, when the unevenness | corrugation which made the cross-section rectangular cross-shaped convex strip 16a and the cross-sectional rectangular groove 16b in the meantime formed also in the lower surface of the lower floor board 4d of the concrete box 4 is formed. Therefore, the installation area of the concrete box 4 can be reduced.

  When the hook-shaped protrusion 14 is formed on the rear end of the side wall plate 1a forming the tail portion 1c of the open shield machine 1, the open shield machine 1 combs the ground when the open shield machine 1 moves forward, A concave groove 15 is horizontally attached to the ground. At that time, a clean groove 15 is formed in the natural ground by the tapered tip end surface 14 a of the protrusion 14.

  The secondary injection plastic back injection material 6b is filled and hardened in the concave groove 15 attached to the natural ground, and the friction with the box by the back injection material can be further increased. .

It is a vertical front view shown as one embodiment of the open shield method of the present invention. It is a front view which shows 1st Embodiment of the concrete box used with the open shield method of this invention. It is a perspective view which shows 1st Embodiment of the concrete box used with the open shield construction method of this invention. It is a side view which shows 1st Embodiment of the concrete box used with the open shield construction method of this invention. It is explanatory drawing of the unevenness | corrugation of 1st Embodiment of the concrete box used with the open shield construction method of this invention. It is a front view which shows 2nd Embodiment of the concrete box used with the open shield construction method of this invention. It is a perspective view which shows 2nd Embodiment of the concrete box used with the open shield construction method of this invention. It is a side view which shows 2nd Embodiment of the concrete box used with the open shield construction method of this invention. It is a front view which shows 3rd Embodiment of the concrete box used with the open shield construction method of this invention. It is a perspective view which shows 3rd Embodiment of the concrete box used with the open shield construction method of this invention. It is a side view which shows 3rd Embodiment of the concrete box used with the open shield construction method of this invention. It is a front view which shows 4th Embodiment of the concrete box used with the open shield construction method of this invention. It is a perspective view which shows 4th Embodiment of the concrete box used with the open shield construction method of this invention. It is a side view which shows 4th Embodiment of the concrete box used with the open shield method of this invention. It is a front view which shows 5th Embodiment of the concrete box used with the open shield construction method of this invention. It is a perspective view which shows 5th Embodiment of the concrete box used with the open shield construction method of this invention. It is a side view which shows 5th Embodiment of the concrete box used with the open shield construction method of this invention. It is a cross-sectional top view shown with one Embodiment of the open shield construction method of this invention. It is a vertical front view of the open shield machine used with the open shield method of the present invention. It is a perspective view of the rear end part of the open shield machine used with the open shield construction method of the present invention. It is a vertical side view which shows the outline of an open shield construction method. It is a perspective view of a concrete box. It is explanatory drawing which shows a backfill injection material (primary injection construction). It is explanatory drawing which shows a backfill injection material (secondary injection construction).

DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a ... Side wall plate 1b ... Bottom plate 1c ... Tail part 2 ... Propulsion jack (shield jack)
DESCRIPTION OF SYMBOLS 3 ... Partition 4 ... Concrete box 4a ... Left side plate 4b ... Right side plate 4c ... Upper floor board 4d ... Lower floor board 5 ... Backfill soil 6, 6a, 6b ... Back injection material 7 ... Height adjustment material 8 ... Press bar 9 DESCRIPTION OF SYMBOLS ... Excavator 10 ... Opening 11 ... Cutting edge 12 ... Grout hole 13 ... Injection nozzle 14 ... Protrusion 14a ... Tapered tip surface 15 ... Groove 16a ... Horizontal beam-like convex 16b ... Groove 17a ... Horizontal beam-like convex 17b ... groove 18a ... mountain 18b ... valley 19 ... nashiji 20a ... circular protrusion

Claims (1)

The process of excavating and discharging soil in front of the front or top opening of the open shield machine, the process of extending the propulsion jack and advancing the shield machine with the concrete box as a reaction force, and shrinking in the tail part of the shield machine The process of suspending and setting a new concrete box behind the propulsion jack was repeated from time to time, and the concrete boxes were sequentially embedded in columns.After the concrete boxes were installed in the tail, Perform primary injection to inject and fill plastic back injection material into the gap with the outer surface of the box, and secondary injection to inject and fill plastic back injection material into the tail void at the same time as the shield machine advances. in the open shield method, concrete box body is Yes to form irregularities on the left and right side plates outer surface, primary infusion Engineering Urakomi injection material of this in the tail portion of the shield machine Joined with a box body with a convex, open shield construction method is characterized in that to increase the friction of a box body and Urakomi grout.

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