JP5389869B2 - Open shield method - Google Patents

Description

  The present invention relates to an open shield method for constructing an underground structure such as an underground passage such as a water and sewage system, a common ditch, a telegraph / telephone, etc. in an urban area.

Open shield method is a method rich in rationality which utilizes the open-cut method (open cut method) the advantages of shield tunneling, left and right side walls of like outline of the open shield machine 1 shown in FIG. 7 to be used in this open shield tunneling The front, rear, and top surfaces of the plate 1a and the bottom plate 1b connected to the side wall plates 1a are opened, the front ends of the side wall plate 1a and the bottom plate 1b are formed as blade edges 11, and the center of the side wall plate 1a is formed. Alternatively, the shield jacks 2 are arranged side by side in the vertical direction near the rear end. In the figure, 3 indicates a partition wall.

  The open shield method to be constructed using the open shield machine 1 is not shown in the figure, but the open shield machine 1 is installed in the start pit, the shield jack 2 of the open shield machine 1 is extended, and the inside of the start mine is The open shield machine 1 is advanced by taking the reaction force against the reaction wall, the first concrete box 4 forming the underground structure is suspended from above, and the shield is shrunk in the tail part 1c of the open shield machine 1 Set behind jack 2. 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 opened in the tail part 1c. The primary back injection material 6 is primarily injected into the gap between the shield machine 1 and the bottom plate 1 b below the bottom of the concrete box 4 and the gap between the left and right sides of the concrete box 4 and the shield machine 1.

The filling of the primary back injection material 6 is performed after the concrete box 4 is set and before the open shield machine 1 is propelled as shown in FIG. 9 , and when the primary injection is completed, it is shown in FIG. In this way, the face mountain 12 is excavated by an excavator such as a backhoe, and loosening and collapse of the ground mountain on the side of the face mountain 12 is prevented by a slide retaining plate 13 provided at the blade edge 11.

If the open shield machine 1 is propelled in this way, tail voids are generated accordingly. Teruboido is a gap in which the bottom plate 1b occurs in the right and left gaps and concrete box making body 4 formed here after the advancing here as further shown in FIG. 11 by injecting secondary Urakomi injection member 14, The filling of the backfill material is completed.

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

Concrete a box body 4 is made of reinforced concrete, made of a left side plate 4a, the right plate 4b and the upper floor plate 4c and the lower floor 4d as shown in FIG. 8, are open to the front and rear surfaces as the opening 10.

  The prior art is generally performed by those skilled in the art, and is not related to a known invention.

  As described above, the primary back injection material 6 includes the gap between the inside of the open shield machine 1 and the bottom plate 1b below the bottom of the concrete box 4 and the left and right sides of the concrete box 4 and the shield machine 1 in the tail part 1c. However, the front side of the filling portion is an open surface, and the primary backfilling injection material 6 may flow out from here.

  The outflow will be compensated by the secondary back injection material 14, and the thickness of the secondary back injection material 14 will be increased.

  When propelling the open shield machine 1, struts and the like are disposed at the front end portions of the concrete box 4 and the primary backfilling material 6, but the temporary backfilling material 6 flows out in such a member. It is difficult to prevent.

  In order to eliminate the inconveniences of the conventional example, the present invention provides an open shield method that prevents the primary backfill injection material from flowing out and prevents the secondary backfill injection material from becoming thick.

The invention described in claim 1 includes a step of excavating and discharging the earth and sand in front of the front or upper surface opening of the open shield machine, a step of digging the shield machine by using a concrete box as a reaction force, and a jack portion of the shield machine. In the process of suspending a new concrete box from above and setting it in the tail part of the rear of the shield jack shrunk in step as appropriate, and burying the concrete boxes in tandem and setting the concrete box, After setting the concrete box, in the open shield method of filling the gap between the outside of the concrete box and the tail part with the primary backfill injection material, the concrete box set at the place where the primary backfill injection material is filled the front end position, the outflow prevention member perpendicular angle-shaped frame member comprising a mounting piece and deterrence piece, the front end outside of the concrete box-body Is secured to, and arranged so as to be left on the ground, it is an gist to prevent the outflow of the primary Urakomi injected material in the outflow prevention member.

  According to the first aspect of the present invention, since the outflow of the primary back injection material is blocked by the outflow prevention member, not only the injection material is prevented from collapsing, but also the subsequent secondary back injection material is the primary material. It does not flow in the direction of the backfilling injection material, and the thickness of the secondary backfilling injection material can be reduced.

Moreover, since the outflow prevention member is left in the ground while being fixed to the concrete box, there is no need to remove it and the workability is not affected.

Furthermore, the outflow prevention member can use steel, is inexpensive, and is easy to install.

The gist of the present invention described in claim 2 is that the outflow prevention member is provided with a movable plate that slides along the restraining piece.

According to the second aspect of the present invention, the movable plate can be moved so as to protrude outward, and the clearance between the tail portion of the open shield machine and the outflow prevention member can be narrowed.

  As described above, in the open shield method of the present invention, since the outflow prevention member is arranged in the concrete box at the front end portion of the filling portion of the primary backfilling injection material, the outflow of the primary backfilling injection material is prevented. As a result, the collapse of the primary back injection material is prevented and the secondary back injection material does not flow in the direction of the primary back injection material, thereby preventing the secondary back injection material from becoming thick.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a longitudinal front view illustrating an embodiment of an open shield method of the present invention, FIG. 2 is a transverse plan view of the same main part, similarly to the conventional example previously described open basic configuration of the shield tunneling is 7-11 Therefore, detailed description here is omitted.

  In the concrete box 4 used in the open shield method of the present invention, after the concrete box 4 is set on the tail portion 1c, the primary back-filling is filled in the gap between the outside of the concrete box 4 and the open shield machine 1. An outflow prevention member 15 for preventing the injection material 6 from flowing out forward was fixed in the vertical direction at the side front end portion.

  As the first embodiment, the outflow prevention member 15 is a right-angled frame material, one side of which is an attachment piece 17a to the concrete box 4, and the other side is a deterrent piece that projects from the concrete box 4 to the side. 17b, and both were reinforced and joined by a triangular reinforcing rib plate 17c.

  The attachment pieces 17a and the restraining pieces 17b are strip steel members that are continuous in the length direction, and the reinforcing rib plates 17c are arranged at appropriate vertical intervals in the horizontal orthogonal direction (only the upper and lower ends may be provided).

  The mounting piece 17a is fixed to the concrete box 4 with a hole anchor 16, and the fixing direction is such that one side forming a right-angled portion of a right triangle is joined to the outer surface of the concrete box 4 and the hypotenuse is the primary backfilling injection material 6 It becomes the direction which joins to the front end of the

  The direction of the right-angled portion of the right triangle may be such that the reinforcing rib plate 17c faces the rear of the concrete box 4 as shown in FIG. 3, or faces the front as shown in FIG. May be.

  Moreover, although the outflow prevention member 15 may be installed in all the concrete boxes 4, you may install every other box with respect to the concrete box 4 to be laid.

  The outflow prevention member 15 can be attached to the concrete box 4 in advance when the concrete box 4 is installed on the tail 1c of the open shield machine 1.

  A method for laying the concrete box 4 to which the outflow prevention member 15 is attached will be described. The open shield machine 1 is dug down, the concrete box 4 is suspended in the tail part 1c of the open shield machine 1, and the bottom plate 1b below the bottom of the concrete box 4 from the inside of the open shield machine 1 in the tail part 1c The primary back-filling injection material 6 is primarily injected into the gap between the left and right sides of the concrete box 4 and the shield machine 1.

  At the time of filling the primary backfilling material 6, an outflow prevention member 15 fixed to the concrete box 4 is installed at the front end of the gap between the side of the concrete box 4 and the left and right side wall plates 1 a of the open shield machine 1. Therefore, the primary back injection material 6 filled here is prevented from flowing out from the gap. This prevents the primary backfilling material 6 from collapsing.

  As shown in FIG. 1, the clearance (t) between the tail portion 1 c of the open shield machine 1 and the outflow prevention member 15 is as small as possible with respect to the primary injection thickness (S) of the primary backfill injection material 6. Is desirable.

  If primary injection is completed in this way and the open shield machine 1 is dug, tail voids are generated accordingly. The tail void is a gap formed here after the bottom plate 1b moves forward and a gap generated between the primary back-filling material 6 and the ground on the left and right sides of the concrete box 4 and is further filled with the secondary back-filling. Material 14 is injected.

  In this case, since the primary back injection material 6 is prevented from collapsing due to flow out and the injection thickness is secured as described above, the secondary back injection material 14 is moved toward the primary back injection material 6 as a result. It does not flow and the thickness of the secondary back injection material 14 does not increase.

  The outflow prevention member 15 is fixed to the concrete box 4 laid in the ground and is left in the ground as it is. Therefore, the trouble of removing the outflow prevention member 15 is not required.

  And since the outflow prevention member 15 has a right-angled triangular hypotenuse in contact with the primary backfilling injection material 6, the outflow prevention member 15 does not contact with the secondary backfilling injection material 14, and therefore the primary backfilling injection material 6 The outflow prevention member 15 is not interposed between the secondary back injection material 14 and the primary back injection material 6 and the secondary back injection material 14 are integrated.

  As shown in FIGS. 1 and 2, the lateral width of the outflow prevention member 15 is slightly narrower than the filling thickness of the primary back-filling injection material 6 [clearance (t)], The primary back injection material 6 is present on the entire rear side of the outflow prevention member 15, and the outflow prevention member 15 is a slight line between the primary back injection material 6 and the secondary back injection material 14. The primary back injection material 6 and the secondary back injection material 14 are completely integrated.

  Further, as a third embodiment, as shown in FIGS. 5 and 6, an angle-shaped outflow prevention member 15 comprising an attachment piece 17a and a restraining piece 17b, the restraining piece 17b has a movable plate 17d that slides along this. In addition, after the concrete box 4 is installed, the movable plate 17d is moved so as to protrude outward, and the clearance (t) between the tail portion 1c of the open shield machine 1 and the outflow prevention member 15 is narrowed. Good.

  The movable plate 17d was provided with a laterally elongated hole, and was fixed to the restraining piece 17b with a bolt 18, thereby forming a widening material for the restraining piece 17b.

  By doing this, the movable plate 17d is moved according to the size of the clearance (t) between the tail portion 1c of the open shield machine 1 and the outflow prevention member 15, thereby reliably preventing the outflow of the primary back injection material 6. It becomes possible to do.

  Further, when the concrete box 4 is suspended in the tail portion 1c of the open shield machine 1, the movable plate 17d is retracted as shown in FIG. 5 so that the clearance (t) is increased to facilitate the suspension. it can.

It is a vertical front view which shows embodiment of the open shield construction method of this invention. It is a cross-sectional top view of the principal part which shows 1st Embodiment of the open shield method of this invention. It is a top view of the principal part which shows 1st Embodiment of an outflow prevention member. It is a top view of the important section showing a 2nd embodiment of an outflow prevention member. It is a top view of the important section showing a 3rd embodiment of an outflow prevention member. It is a top view of the principal part after the change which shows 3rd Embodiment of an outflow prevention member. 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 a top view at the time of the primary injection before promotion of an open shield machine. It is a top view at the time of excavation of Mt. It is a top view at the time of propulsion and secondary injection of an open shield machine.

DESCRIPTION OF SYMBOLS 1 Open shield machine 1a Side wall plate 1b Bottom plate 1c Tail part 1d Front part 1e Jack part 2 Shield jack 3 Bulkhead 4 Concrete box 4a Left side board 4b Right side board 4c Upper floor board 4c Lower floor board 4d Lower floor board 5 Backfill soil 6 Injection material 7 Height adjusting material 8 Press bar 9 Excavator 10 Opening 11 Cutting edge 12 Face mound 13 Slide retaining plate 14 Secondary backfilling injection material 15 Outflow prevention member 16 Hole anchor 17a Mounting piece 17b Suppression piece 17c Reinforcement rib plate 17d Movable plate 18 Bolt 19 Curved plate 19a Mounting piece 20 Back-filling injection material

Claims (2)

The process of excavating and discharging soil in front of the front or top opening of the open shield machine, the process of advancing the shield machine with the reaction force of the concrete box, and the rear of the shield jack shrunk in the jack part of the shield machine The process of suspending and setting a new concrete box on the tail part from above is set as appropriate, and the concrete box is sequentially embedded in the column. In the step of setting the concrete box, the concrete box is set after the concrete box is set. In the open shield method that fills the gap between the outer side of the box and the tail part with the primary backfilling injection material, at the filling position of the primary backfilling injection material, at the front end position of the set concrete box and restraint A right-angled frame member with a right angle is fixed to the outside of the front end of the concrete box and remains in the ground. Open shield method, characterized in that the arranged as to prevent leakage of primary Urakomi injected material in the outflow prevention member.   The open shield method according to claim 1, wherein the outflow prevention member is attached with a movable plate that slides along the restraining piece.

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