JP5081858B2 - Open shield machine - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an open shield machine that uses an underground structure such as an underground passage such as a water and sewage system, a common ditch, a telegraph / telephone, etc. for construction in an urban area or the like.

  The open shield method is a rational method that utilizes the advantages of the open cut method (open cut method) and the shield method, and the outline of the open shield machine 1 used in this open shield method is shown in FIGS. The front, rear and top surfaces of the left and right side wall plates 1a and the bottom plate 1b connected to the side wall plates 1a are opened. The front ends of the side wall plates 1a and the bottom plate 1b are front portions 1d, and the front ends thereof are blade edges. 11 was formed.

  In the figure, 12 is a slide retaining plate disposed on the left and right of the front end of the front portion 1d, 13 is a slide jack for propelling the slide retaining plate 12, and 14 is a bent jack that changes the propulsion direction by changing the stroke length. Indicates.

  Further, the shield jack 2 is arranged in the vertical direction at the center or near the rear end of the side wall plate 1a, and this portion is referred to as a jack portion 1e. In the figure, 3 indicates a partition wall.

  A rear portion of the jack portion 1e is a tail portion 1c for hanging the concrete box 4 down.

  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 jack part 1e 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 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 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 back injection material 6 is primarily injected into the gap between the inside of the shield machine 1 and the bottom plate 1b below the bottom of the concrete box 4, and further, the open shield machine 1 is advanced, and the bottom plate 1b is formed here after the advance. The back-filling material 6 is further injected into the gap and the left and right sides of the concrete box 4 to complete the filling of the back-filling material.

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

  As described above, the open shield machine excavated by the open shield method is excavated with a stable slope in front of Mt. In this case, excavation of the front face mountain is carried out while balancing the thrust of the shield machine and the front face mountain as the shield machine advances. For this reason, although the shape of the face hill is excavated while maintaining a stable state, it always changes.

  By the way, in the conventional open shield machine, as shown in FIG. 7, in order to prevent the front part 1d from collapsing from the bulkhead 3 for preventing the intrusion of earth and sand into the open shield machine 1 and the face from the ground side. Although the slide retaining plate 12 is provided, there has not been established as a means for preventing collapse of the natural ground from the front of the face.

  For this reason, as shown in FIG. 7, when the construction site is, for example, a ground with a low level of groundwater and a loose sandy soil, excavation is performed while accumulating groundwater and soil in the front part. When excavating the part of the face A during propulsion, part of the slope may collapse like B, affecting the area around the front face of the face, for example, the stability of the scaffolding of excavating heavy equipment placed in front May not be able to be secured, and there is a risk of hindering construction.

  The present invention eliminates the inconvenience of the conventional example, for example, when the construction site is a sandy soil with a high groundwater level and a loose sandy soil, depending on the propulsion amount of the open shield machine and the state of the face of Mt. An open shield machine that can keep the ground in the front part in a stable state and prevent the ground from collapsing is provided.

In order to achieve the above object, the invention according to claim 1 is an open shield machine comprising a front part having a blade edge, a jack part having a shield jack, and a tail part for hanging a concrete box. In this case, a face retaining plate is disposed at a front position of the partition wall disposed in the front portion, and a face retaining retaining jack is disposed at least in two upper and lower stages with the face retaining plate positioned at the left and right ends of the face retaining plate. It is configured to move forward and backward in the propulsion direction of the open shield machine by expansion and contraction of the jack, and it is provided so that the inclination angle of the face retaining plate can be set by changing the vertical expansion and contraction amount of the face retaining movement moving jack. Is a summary.

  According to the first aspect of the present invention, since the face retaining plate is further disposed at the front position of the partition wall disposed at the front portion of the open shield machine, the face retaining plate is movable, and the front facing surface is provided. Pressed against the mountain. As a result, it is possible to always keep the face of Mt. In particular, even when the excavation work is temporarily stopped, the open area of the face mountain can be reduced by pressing the face retaining plate against the face, which is safe.

Also, the face retaining plate can be easily moved because it moves in the longitudinal direction of the propulsion direction of the open shield machine by the expansion and contraction of the face retaining ring moving jack.

  In addition, the tilt angle of the face retaining plate is set by changing the vertical expansion / contraction amount of the installed face retaining moving jack, so the face retaining plate can be almost matched to the natural gradient of the natural ground in the front part. , The stability of the natural ground can be made more reliable. This is particularly effective when it is necessary to keep the slope of Mt.

  As described above, the open shield machine of the present invention is based on the amount of propulsion of the open shield machine and the state of Mt. The natural ground in the front part can always be kept in a stable state, and natural ground collapse can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view showing an embodiment of the open shield machine of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a longitudinal front view of a portion of the same face retaining plate, and the conventional example shown in FIGS. The same components as those in FIG.

  The basic structure of the open shield machine 1 of the present invention is the same as that of the prior art, and includes a front portion 1d, a jack portion 1e, and a tail portion 1c. The front portion 1d has a slide jack 13 and a slide earth retaining plate 12 on the left and right sides. Is disposed, and a bent jack 14 for changing the traveling direction of the open shield machine 1 by changing the stroke difference is disposed inside.

  The jack portion 1e is provided with a shield jack 2 for propelling the open shield machine 1 by taking a reaction force against the concrete box at the rear, and the tail portion 1c has a space for hanging the concrete box. ing.

In the open shield machine 1 having such a configuration, the face retaining plate 15 that is positioned in front of the partition wall 3 inside the left and right side wall plates 1a of the front portion 1d and closes the front opening of the front portion 1d as shown in FIG. It was provided movably .

  The face retaining plate 15 is located at the left and right ends of the face retaining plate, and the face retaining moving jack 16 is disposed at least in two upper and lower stages. The propulsion direction of the open shield machine 1 is extended and contracted by the face retaining moving jack 16. The plurality of face retaining ring moving jacks 16 can each be independently set with an expansion / contraction stroke.

  Next, the operation will be described. Since the basic configuration of the open shield method has already been described with reference to FIG. 6, detailed description thereof is omitted here. FIG. 2 shows the case where the face retaining plate 15 is in the retracted position before the movement, and the face retaining movement jack 16 is in a contracted state.

  When the open shield machine 1 is excavated, for example, when the face becomes sandy ground with a high groundwater level, the slope of the excavation tends to collapse, but in such a case, as shown in FIG. The face retaining plate 15 is extended and moved forward in the front portion 1d.

  As a result, the face retaining plate 15 is pressed against the natural ground in the front portion 1d, and collapse of the lower part of the slope of excavation can be prevented. Further, by pressing the face retaining plate 15 against the natural ground, the height of the excavation slope is lowered, and the stability of the excavation slope is improved.

  Also, when the excavation work is temporarily stopped, if the face retaining plate 15 is pressed against the natural ground in the state shown in FIG. 4, the open area of the face natural ground can be reduced and it is safe.

  Further, as described above, since the plurality of face retaining movement moving jacks 16 are installed and can be expanded and contracted by different stalks, the amount of expansion and contraction of the face retaining movement moving jacks 16 at the upper and lower positions can be changed as shown in FIG. The face retaining plate 15 can be inclined at an arbitrary angle toward the front. Accordingly, the face retaining plate 15 can be substantially matched to the normal slope of the face slope in the front portion 1d which is changed by excavation, and the stability of the ground is further improved.

  As described above, the face retaining plate 15 is pressed against the natural ground in accordance with the slope of the natural ground, which is effective when it is necessary to keep the slope of the natural ground during excavation suspension.

It is a vertical side view which shows embodiment of the open shield machine of this invention. It is a top view which shows embodiment of the open shield machine of this invention. It is a vertical front view of the location of the face retaining plate which shows embodiment of the open shield method of this invention. It is a vertical side view of the state which moved the face earth retaining plate which shows embodiment of the open shield machine of this invention to the front. It is a vertical side view of the state where the face retaining plate showing the embodiment of the open shield machine of the present invention is moved while being inclined forward. It is a top view of the conventional open shield machine. It is a vertical side view which shows the excavation state of the conventional open shield machine. 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.

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 5 Backfilling soil 6 Back injection material 7 High 8 Adjusting material 8 Press bar 9 Excavator 10 Opening 11 Cutting edge 12 Slide retaining plate 13 Slide jack 14 Folding jack 15 Face retaining plate 16 Face retaining moving jack

Claims (1)

In an open shield machine composed of a front part having a blade opening, a jack part having a shield jack, and a tail part for hanging a concrete box,
A face retaining plate is disposed at a front position of the partition wall disposed in the front portion, and a face retaining moving jack is disposed at least in two upper and lower stages with the face retaining plate positioned at the left and right ends of the face retaining plate . It is configured to move forward and backward in the propulsion direction of the open shield machine by expansion and contraction, and it is provided so that the inclination angle of the face retaining plate can be set by changing the amount of vertical expansion and contraction of the face retaining ring moving jack. An open shield machine.

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