JP3766423B2 - Retaining wall construction method - Google Patents

Description

  The present invention relates to a method for constructing a retaining wall constructed by installing an L-shaped retaining wall block.

  As a method of constructing a retaining wall, for example, there is a method in which L-shaped precast concrete blocks are installed side by side. If the bottom ground of the installation location is cut down, or if it is installed as a retaining wall on the embankment on an inclined surface, the bottom After excavating the ground or slope with an excavator such as a backhoe, an L-shaped precast concrete block is suspended and installed here with a heavy machine such as a crane (see, for example, Patent Document 1).

  By the way, there is an open shield method as a method for constructing underground structures such as water and sewerage systems, common ditches, telegraphs / telephones, etc. in underground areas.

  The open shield method is a highly rational method that utilizes the advantages of the open cut method (open cut method) and the shield method. 8 and 9, the open shield machine 1 in the figure is an open shield machine 1, which is open on 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. Shield machine.

  In the open shield machine 1, the front ends of the side wall plate 1a and the bottom plate 1b are formed as blade edges 6, and the propulsion jacks 2 are arranged in the vertical direction in the middle or near the rear end of the side wall plate 1a.

  The open shield construction method constructed using such an open shield machine 1 installs this open shield machine 1 in the start pit 3 and extends the propulsion jack 2 of the open shield machine 1 to the reaction wall in the start pit. Take the reaction force to advance the open shield machine 1, suspend the first concrete box 4 forming the underground structure from above, and retract the propulsion jack 2 that is shrunk in the tail part 1 c of the open shield machine 1. Set to. A strut is disposed between the propulsion jack 2 and the reaction wall to adjust the distance appropriately.

  In addition, the start pit 3 is constituted by a retaining wall, and in order to start the open shield machine 1, a part of this retaining wall is mirror-cut, but 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 5 such as an excavator excavates and removes soil from the front or upper surface of open shield machine 1. At the same time as or after this earth removal step, the propulsion jack 2 is extended to advance the open shield machine 1. In the case of this advancement process, a push angle 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 takes a reaction force from the concrete box 4 set rearward. .

  Then, the second concrete box 4 is suspended by the crane 8 in the tail portion 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 on top of body 4.

  When the concrete box 4 is suspended in the tail part 1c of the open shield machine 1, a height adjusting material such as a concrete block is disposed under the concrete box 4 and the concrete box 4 is placed in the tail part 1c. Grout material 7 is filled in the left and right and lower spaces of the body 4.

  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.
JP 2001-329550 A

  The L-shaped precast concrete block has recently been particularly large and tends to handle heavy objects, but its shape is unstable, so there is a danger in hanging and transporting.

  On the other hand, the open shield method that handles heavy-weight concrete boxes is intended for the construction of underground structures such as water and sewage systems, common ditches, telegraphs and telephones as mentioned above. It was not adopted for construction and was not used effectively.

  An object of the present invention is to provide a retaining wall construction method that eliminates the disadvantages of the conventional example, can construct a retaining wall by installing an L-shaped retaining wall block safely and easily, and at the same time can effectively utilize the open shield method. It is in.

  In order to achieve the above object, the present invention is characterized in that the L-shaped block is combined in a box culvert shape with the L-shaped blocks facing up and down, and the soil in front of the open shield machine or the top opening is excavated and discharged. A step of earthing, a step of extending the propulsion jack and making the box culvert-shaped block body a reaction force to advance the shield machine, and a new box culvert-like shape behind the propulsion jack shrunk in the tail portion of the shield machine The step of setting the block body is repeated as appropriate, and the box culvert-like block bodies are sequentially arranged in a column, and the retaining wall is constructed with the L-shaped block located on the lower side by removing the L-shaped block located on the upper side. This is the gist.

  According to the first aspect of the present invention, by making the L-shaped block face up and down to form a box culvert-like block body, this can be handled in the same manner as a concrete box used in the open shield method. Therefore, if this box culvert-shaped block body is installed by an open shield method using an open shield machine, and the L-type block located on the upper side is removed after laying, only the L-type block located on the lower side remains. Thus, an L-shaped retaining wall is constructed.

  In the invention according to claim 2, after burying the box culvert-shaped block body in the ground, the L-shaped block located on the upper side is removed, and the outside of the place where the upper L-shaped block is disposed is excavated. Then, the gist is to cut down the bottom ground to the bottom position of the lower L-shaped block.

  According to the second aspect of the present invention, after the box culvert-shaped block body is installed, the L-shaped block located on the upper side is removed, and only the outside of the portion where the upper L-shaped block was disposed is excavated. Thus, the bottom ground can be easily cut down and the ground can be lowered to the bottom position of the lower L-shaped block.

  The invention according to claim 3 is installed such that a part of the side portion of the L-shaped block located below the box culvert-shaped block body is buried in the ground and the upper surface of the bottom portion is located on the ground surface. After that, the L-shaped block located on the upper side is removed, and the embedding is performed on the upper and outer sides of the side portion of the L-shaped block.

  According to the third aspect of the present invention, if the burying height position of the box culvert-shaped block body is set such that the upper surface of the L-shaped block positioned on the lower side is positioned on the ground surface, the box culvert-shaped block In a state where the body is laid and the L-shaped block located on the upper side is removed, the side portion of the lower L-shaped block protrudes to the front surface of the inclined surface. Therefore, if embankment is applied between the outer side of the side of the lower block and the inclined surface, the lower L-shaped block functions as a retaining wall for this embankment.

  The gist of the invention described in claim 4 is that the upper L-shaped block to be removed after the box culvert-shaped block body is installed can be used in the next construction.

  According to the fourth aspect of the present invention, the removed upper L-shaped block can be used not only as the upper L-shaped block but also as the lower L-shaped block in the next construction. It can be used and materials are not wasted.

  The retaining wall construction method of the present invention is an L-shaped retaining wall that can be safely and easily installed by using an open shield machine with a combination of L-shaped blocks facing each other in a box culvert shape. A retaining wall can be constructed by installing blocks, and at the same time, the open shield method can be used effectively.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a process diagram showing a first embodiment of a retaining wall construction method according to the present invention, which is constructed by the open shield method already described with reference to FIGS. 8 and 9. Instead of the conventional concrete box 4 which has been used, two L-shaped blocks 9a and 9b made of precast concrete which become retaining wall blocks are combined facing each other.

  The L-shaped blocks 9a and 9b have the same shape, and the L-shaped block 9a positioned on the lower side and the L-shaped block 9b positioned on the upper side are coupled with a through bolt to form a box culvert-shaped block body 9.

  In FIG. 1, 10 is an inclined surface for constructing a retaining wall, and the first embodiment is a case where the retaining wall is constructed by lowering the bottom ground 11, and the box culvert-shaped block body 9 is installed by the open shield method described above. In this case, the box culvert-shaped block body 9 is at a height position such that the upper surface of the L-shaped block 9b positioned on the upper side is positioned below the inclined surface 10 at the same level as the bottom ground 11 which is the current ground surface. Is installed.

  Installation of the box culvert-shaped block body 9 by the open shield construction method includes the step of excavating and discharging the soil in front of the open shield machine 1 from the front or top opening of the open shield machine 1 and the extension jack 2 to extend the box culvert. A step of advancing the open shield machine 1 by using the block-shaped block body 9 as a reaction force, and a new box culvert-shaped block body 9 is set behind the propulsion jack 2 contracted in the tail portion 1c of the open shield machine 1 The steps are repeated as appropriate to sequentially arrange the box culvert-shaped block bodies 9 in columns, but since the block bodies 9 are formed in a box culvert shape, this is used as a reaction force to advance the shield machine 1. It becomes possible.

  If the box culvert-shaped block body 9 is installed in the ground while excavating the ground in this way (see FIGS. 1 (a) and 1 (b)), the L-shaped block 9b located on the upper side is removed. Then, the ground outside the L-shaped block 9b is excavated, and the bottom ground 11 is cut down to the bottom position of the lower L-shaped block 9a (see FIG. 1C).

  As a result, the side portion 12 of the lower L-shaped block 9a is disposed below the inclined surface 10, and the bottom portion 13 is positioned on the same plane as the bottom ground 11, and is held by the L-shaped block 9b. A wall is built. The gap formed between the side and bottom portions of the L-shaped block 9a and the surrounding natural ground is filled with the backfilling injection material 14 so as to be integrated with the natural ground. The removed upper L-shaped block 9b is reused as an upper or lower block in the next construction.

  FIG. 2 shows the second embodiment, and the basic configuration is the same as that of the first embodiment, except that backfill injection is not performed, and the crushed stone 15 and the dry concrete 16 are provided below the bottom of the open shield machine 1 to be advanced. And a box culvert-shaped block body 9 is installed.

  And after installing the box culvert-like block body 9 by the open shield method using the open shield machine 1, the L-shaped block 9b located on the upper side is removed, the ground outside thereof is excavated, and the bottom ground 11 is removed. When the level is the same as the bottom of the lower L-shaped block 9a, backfill 17 is applied to the gap formed between the side of the L-shaped block 9a and the surrounding natural ground. Thereby, a retaining wall is constructed by the lower L-shaped block 9a.

  FIG. 3 shows the third embodiment, and the basic configuration is the same as that of the second embodiment. In addition to the configuration of the second embodiment, upper and lower L-shaped blocks as shown in FIG. The through holes 19 of the steel pipe piles 18 are respectively formed at locations located at the bottom 13 of 9a and 9b, and the box culvert-shaped block body 9 is laid by the open shield construction method using the open shield machine 1, and then the upper L-shaped The steel pipe pile is made to penetrate through the through hole 19 formed in the lower L-shaped block 9a from the through hole 19 formed in the block 9b, and further through the dry concrete 16 and the crushed stone 15 installed below the through hole 19 Drive 18 to the ground.

  Thereafter, as shown in FIG. 3 (d), the upper L-shaped block 9b is removed, and the steel pipe pile 18 projecting upward from the bottom 13 of the lower L-shaped block 9a is cut, and the cut steel pipe The steel pipe pile 18 is fixed by filling the gap between the pile 18 and the through hole 19 formed in the lower L-shaped block 9a with the filler 20.

  Therefore, the lower L-shaped block 9a is installed in a state in which the lower L-shaped block 9a is securely fixed to the predetermined position by the steel pipe pile 18, and the retaining wall is constructed.

  In the first to third embodiments described above, the upper surface of the bottom portion 13 of the lower L-shaped block 9a constituting the retaining wall is positioned on the same plane as the bottom ground 11 which has been cut down. -6th Embodiment is a case where a banking is constructed in the lower part of the inclined surface 10, and the retaining wall which functions also as the earth retaining wall of this banking part is constructed | assembled.

  FIG. 4 shows the fourth embodiment, in which the box culvert-shaped block body 9 is installed by the open shield method using the open shield machine 1 as in the first to third embodiments. The box culvert-shaped block body 9 is laid so that the upper surface of the bottom portion 13 of the L-shaped block 9a located on the lower side is located on the same plane as the bottom ground 11.

  After the box culvert-shaped block body 9 is installed as shown in FIG. 4b, the upper L-shaped block 9b is removed as shown in FIG. 4 (c), and the upper portion of the side portion 12 of the lower L-shaped block 9a is removed. The portion projects perpendicularly to the lower part of the inclined surface 10, and a gap is formed between the inclined surface 10 and the outside of the side portion 12. Therefore, the embankment 21 is constructed by refilling the gap. The gap formed between the lower L-shaped block 9a and the natural ground is filled with the backfilling injection material 14 to achieve integration with the surrounding natural ground.

  Therefore, the retaining wall is constructed by the lower L-shaped block 9a, and the L-shaped block 9a also functions as a retaining wall for the portion where the embankment 21 is constructed.

  FIG. 5 shows a fifth embodiment. Similarly to the fourth embodiment, a box culvert-shaped block body 9 is opened using the open shield machine 1 by the open shield method, and the bottom portion 13 of the L-shaped block 9a located on the lower side. The box culvert-shaped block body 9 is installed at a height such that the top surface of the block body 9 is flush with the bottom ground 11. As the shapes of the L-shaped blocks 9 a and 9 b constituting the block body 9, As shown in FIG. 5 (b), a non-sliding key 22 is projected from the bottom portion 13 by means of a ridge at a right angle outward.

  And the crushed stone 15 and the dry concrete 16 are installed under the bottom part of the open shield machine 1 advanced like 2nd Embodiment, the box culvert-shaped block body 9 is installed, and the L-shaped block 9b located in the upper side To remove. In this state, the anti-sliding key 22 penetrates the crushed stone 15 and the dry concrete 16 to reach the ground, and functions as a pile.

  The gap formed between the side portion of the lower L-shaped block 9a and the surrounding natural ground is backfilled 17 and further formed between the inclined surface 10 and the outside of the side portion 12 of the L-shaped block 9a. The embankment 21 is constructed by refilling the gap. Thereby, a retaining wall is constructed by the lower L-shaped block 9a.

  FIG. 6 shows a sixth embodiment. Similarly to the fourth embodiment, a box culvert-shaped block body 9 is opened using the open shield machine 1 by the open shield method, and the bottom portion 13 of the L-shaped block 9a located on the lower side. The box culvert-shaped block body 9 is installed at a height such that the upper surface of the box culvert is located on the same plane as the bottom ground 11. The L-shaped blocks 9 a and 9 b constituting the box culvert-shaped block body 9 are provided. It is assumed that the same through-hole 19 as that of the third embodiment is provided, and the steel pipe pile 18 is fixed by driving the lower L-shaped block 9a through the lower dry concrete 16 and the crushed stone 15 into the ground.

  The gap formed between the side portion of the lower L-shaped block 9a and the surrounding natural ground is backfilled 17 and further formed between the inclined surface 10 and the outside of the side portion 12 of the L-shaped block 9a. The embankment 21 is constructed by refilling the gap. Thereby, a retaining wall is constructed by the lower L-shaped block 9a.

  As shown in FIG. 7, there are various types of joints between the upper L-shaped block 9b and the lower L-shaped block 9a. 7b, a combination of a convex part projecting upward and a concave part, and a combination of a convex part projecting in the horizontal inner direction as shown in FIG. 7C and a horizontal concave part into which the convex part is inserted. FIG. 7D shows a combination of a chevron-shaped protrusion and a tapered groove, FIG. 7E shows a combination of a rectangular protrusion and a rectangular groove, and FIG. ), For example, a configuration in which the joining end faces of the lower L-shaped block 9a on the lower side are formed wide and the end faces are brought into contact with each other, as shown in FIG. There is a structure in which the joint end faces are slightly projected and the end faces are brought into contact with each other. In these cases, the combination of the convex portion and the concave portion may be formed oppositely with the upper and lower L-shaped blocks.

It is process drawing which shows 1st Embodiment of the construction method of the retaining wall of this invention. It is process drawing which shows 2nd Embodiment of the construction method of the retaining wall of this invention. It is process drawing which shows 3rd Embodiment of the construction method of the retaining wall of this invention. It is process drawing which shows 4th Embodiment of the construction method of the retaining wall of this invention. It is process drawing which shows 5th Embodiment of the construction method of the retaining wall of this invention. It is process drawing which shows 6th Embodiment of the construction method of the retaining wall of this invention. It is explanatory drawing which shows the joining structure of an L-type block. It is a top view of an open shield construction method. It is a side view of an open shield construction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Open shield machine 1a Side wall plate 1b Bottom plate 1c Tail part 2 Propulsion jack 3 Start pit 4 Concrete box 5 Excavator 6 Cutting edge 7 Grout material 8 Crane 9 Box culvert-shaped block body 9a, 9b L-shaped block 10 Inclined surface 11 Bottom ground 12 Side 13 Bottom 14 Backfilling material 15 Crushed stone 16 Dry concrete 17 Backfill 18 Steel pipe pile 19 Through hole 20 Filler 21 Filling 22 Non-slip key

Claims (4)

  A box culvert-shaped block body in which L-shaped blocks are vertically opposed to each other and combined in a box culvert shape, excavating and discharging soil in front of the open shield machine or from the top opening, and extending a propulsion jack The process of advancing the shield machine with the reaction force and the process of setting a new box culvert-like block body behind the propulsion jack shrunk in the tail part of the shield machine are repeated as appropriate to form the box-culvert block body. A method for constructing a retaining wall, wherein the retaining wall is constructed by sequentially arranging in a column, removing the L-shaped block located on the upper side, and constructing the retaining wall with the L-shaped block located on the lower side.   After burying the box culvert-shaped block body in the ground, the L-shaped block located on the upper side is removed, the outside of the place where the upper L-shaped block was placed is excavated, and the lower L-shaped The method for constructing a retaining wall according to claim 1, wherein the bottom ground is cut down to the bottom position of the block.   The L-shaped block located on the lower side of the box culvert-shaped block body is installed so that a part of the side part is buried in the ground and the upper surface of the bottom part is located on the ground surface. The method for constructing a retaining wall according to claim 1, wherein the mold block is removed, and embankments are constructed on the upper and outer sides of the side portion of the L-shaped block.   The method for constructing a retaining wall according to claim 1 or 2, wherein the upper L-shaped block to be removed after the box culvert-shaped block body is installed can be used in the next construction. .

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