JP4598731B2 - Concrete box - Google Patents

Description

  The present invention is a concrete box used in an open shield method or a propulsion method for constructing underground structures such as waterworks and sewerage systems, common grooves, telegraphs / telephones and other underground structures in urban areas, etc. In particular, the present invention relates to a concrete box that can be suitably used.

  The propulsion method and the open shield method are widely used as methods for constructing underground structures such as water and sewage systems, common ditches, telegraphs and telephones, etc. in urban areas. With the propulsion method, a concrete box or a fume pipe is suspended and set in the excavation hole while excavating the face with an excavator, and the concrete box or the like is pushed out by a propulsion jack placed on the start pit. It is a method of burying concrete boxes etc. in columns in sequence by repeating the process of securing the space for setting the next concrete boxes. Usually, a blade or an excavator is installed in front of the top concrete box or the like.

On the other hand, the open shield method is a highly rational method utilizing the advantages of the open cut method (open cut method) and the shield method. For example, patent documents relating to the open shield method include the following.
JP 2006-112101 A JP 2006-112100 A

  The outline of the open shield machine 1 used in this open shield construction method is as shown in FIG. 4, with the front, rear and top surfaces comprising left and right side wall plates 1a and bottom plates 1b connected to these side wall plates 1a being opened. The front ends of the side wall plate 1a and the bottom plate 1b are formed as blade edges 11, and the propulsion jacks 2 are arranged side by side up and down at the center or near the rear end of the side wall plate 1a. In the figure, 3 indicates a partition wall.

  The open shield method to be constructed using such an open shield machine 1 is not shown in the figure, but this open shield machine 1 is installed in the start pit, and the propulsion jack 2 of the open shield machine 1 is extended so as to be within the start mine. The open shield machine 1 is advanced by taking the reaction force against the reaction force wall, the first concrete box 4 forming the underground structure is suspended from above, and the propulsion is shrunk in the tail portion 1c of the open shield machine 1 Set behind jack 2. A strut is disposed between the propulsion 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. 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 this advancement process, a press bar 8 made of a frame made of box steel or mold steel is arranged in front of the concrete box 4, and the open shield machine 1 reacts from the concrete box 4 set on the rear side. 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. The grout material 6 is filled in the left and right and lower spaces of the box 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.

  The concrete box 4 is made of reinforced concrete and comprises 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. In the figure, 12 is a sheath hole for inserting a PC steel bar as a fastening member that opens to the end surface 4e and fastens the front and rear concrete boxes 4, and 17 shows a box opening for wearing a PC steel bar.

  In order to secure the strength of the concrete box 4, the corner corner haunch portion 4f is generally a haunch shape with a large concrete thickness, and the shape of the opening 10 is chamfered.

  By the way, when performing curved construction, as the open shield machine 1, the machine body is divided into a plurality of parts in the front-rear direction, and the use position and number of the propulsion jacks 2 are mainly changed as a half-folded structure that can independently change the direction. Proceed with directional control in the vertical and horizontal directions.

  As shown in FIG. 6, when the open shield machine 1 moves forward while drawing a reaction force on the concrete box 4, an unbalanced force is applied to the concrete box 4 with the left and right propulsion jacks 2. In addition, as indicated by the alternate long and short dash line, the open shield machine 1 is inclined with respect to the concrete box 4, so that the force applied to the leading concrete box 4 is not equal to the end surface but an eccentric thrust acts.

  As a result, a force that causes displacement between the joining end surfaces of the concrete boxes 4 in parallel works, and a so-called point touch in which the end surfaces 4e are only in partial contact with each other at the connecting portion of the concrete box 4 occurs. There is a risk that the stress will be concentrated and the concrete will be damaged.

  When performing curved construction in this way, the force that causes the displacement of the joint surface of the concrete box 4 is particularly large. However, even in the case of straight construction, the concrete box 4 is rolled by the open shield machine 1 or by pitching. The force applied to the end face 4e is biased, causing the joint surface of the concrete box 4 to be displaced and causing the concrete to break.

  Further, when the end surface 4e of the concrete box 4 is finished with a trowel, unevenness (unevenness) is generated on the end surface 4e. In this case as well, when a thrust is applied to the concrete box 4, a point touch occurs and a crack occurs. It was the cause.

  By the way, the propulsion reaction force of the open shield machine 1 is evenly transmitted to the connection end face of the concrete box 4 and the buffer material is attached to the end face 4e of the concrete box 4 so that the concrete is not damaged at the connection end face. Is generally done. Moreover, as a buffer material, a plywood, a hard plastic, etc. are used normally.

  In other words, the cushioning material affixed to the end face 4e of the concrete box 4 is less likely to cause the displacement of the connecting end face of the concrete box 4 due to the eccentric driving force of the open shield machine 1 due to curve construction, rolling, pitching or the like. It has the function of absorbing the unevenness of the connecting end face of the concrete box 4 and making it difficult to produce point touches.

  However, when plywood is used as a cushioning material, the performance greatly changes depending on humidity, and it is likely to corrode and may cause water leakage from the connecting portion of the concrete box 4 due to aging.

  In addition, when using a buffer material made of resin such as hard plastic that is resistant to corrosion, in order to increase the pressure receiving area of the buffer material on the end surface of the concrete box, it is desirable to attach the buffer material as widely as possible to the end surface of the box. However, when a propulsive force is applied to the concrete box, the buffer material is compressed by the pressure, spreads along the box end face, and protrudes from the box end face.

  If the buffer material is left in a state where it protrudes, the buffer material may be damaged from the protruding portion, and the buffer function may not be maintained. Moreover, if the buffer material which protruded at the time of construction is cut out in order to avoid this, it will become a big effort at the time of construction.

  However, in order to prevent such shock-absorbing material from protruding from the box connection end face, if a hard material with a narrow plastic area against stress is used as the shock-absorbing material, the shock-absorbing material will not be affected by the thrust of the propulsion jack. It does not deform sufficiently along the unevenness of the end face, and the unevenness of the box connection end face cannot be absorbed. In addition, since the hard cushioning material does not adhere to the box connection end face, the eccentric thrust of the propulsion jack at the time of curve construction cannot be transmitted uniformly to the box connection end face.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and in a concrete box that is sequentially arranged in a row for underground burial and receives the thrust of a propulsion jack, the buffer material is securely adhered to the box connecting end face. In addition to transmitting the thrust uniformly to the joint end faces of the box to prevent the gap between boxes, the unevenness of the box end faces is absorbed to prevent point touch and damage to the concrete. It is to provide a concrete box that can maintain the above.

In order to achieve the above-mentioned object, the present invention provides a concrete box that is sequentially arranged in a tandem for underground use and receives thrust from a propulsion jack, and is made of a resin in which a non-stretchable sheet made of metal foil or face cloth is embedded. a composite cushioning member sandwiching the rubber having elasticity in a strip of cushioning material according to the material, the composite cushioning member widely, and deposited on the end face of the longitudinal direction of a box body, is parallel to the composite cushioning member, the sealing member The gist is to adhere to the end face of the box.

  According to the first aspect of the present invention, since the cushioning material is made of a resin material having a wide plastic area against stress, the cushioning material compressed by the thrust of the propulsion jack is flexibly deformed in the compression direction, Securely adheres to the connecting end face of the body. And because this cushioning material is applied widely to the end face in the front-rear direction of the box, even when thrust is applied nonuniformly to the joint end face of the concrete box, or even if there is unevenness on the end face of the concrete box , The cushioning material is in close contact with the box connection end face to transmit thrust uniformly to prevent the box from shifting, and to absorb the unevenness of the box end face to prevent point touch on the box end face. Can prevent the breakage of concrete.

  And since we used a material with a small Poisson's ratio that does not spread easily even under stress, the cushioning material itself is difficult to spread by compression, and the cushioning material is widely applied to the front and rear end faces of the box. However, the cushioning material compressed by the thrust of the propulsion jack does not protrude from the box connection end surface. That is, the buffer material breaks out from the portion protruding from the box connection end face, so that the effects of preventing slippage and preventing concrete breakage are not lost over time.

  Furthermore, the use of a resin-made cushioning material that hardly changes in performance due to humidity and hardly corrodes can maintain the action of preventing slippage and preventing concrete breakage at the box connection part.

  Since the non-stretchable sheet is embedded in the cushioning material to form a composite cushioning member, the cushioning material is restricted from spreading in the width direction by the non-stretchable sheet, making it more difficult to spread, and the composite cushioning compressed by the thrust of the propulsion jack The member does not protrude from the box connection end face.

  Since the non-stretch sheet is made of a metal foil or face cloth that is widely available on the market, in addition to the above-described function, it is easy to create a composite cushioning member that embeds such a non-stretch sheet in a cushioning material. Can do.

Furthermore, by a composite cushioning member sandwiching the rubber having elasticity between the buffer material, adhesion to a box body connection end face is further improved by the resilience of the rubber.

  Since the sealing material is attached to the box end face in parallel with the composite cushioning member, in addition to the cushioning action by the composite cushioning member, the water stopping action of the box connecting portion by the sealing material can also be obtained. That is, this sealing material is compressed between the concrete boxes and exhibits a water stop effect.

  And since the box connection part is protected by a composite cushioning member that is hard to be corroded or damaged, the sealing material of the box connection part is also protected by such a composite cushioning member, and the water stop function is maintained. Can do.

  As described above, in the concrete box of the present invention, even when thrust is applied non-uniformly to the joint end face of the concrete box or when there is unevenness on the end face of the concrete box, the cushioning material is applied to the box connecting end face. It is possible to prevent the point touch and prevent the breakage of the concrete by making sure that it is in close contact, and to maintain the buffering action at the box connecting portion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall perspective view showing a first embodiment of a concrete box according to the present invention. The same components as those in the conventional example are given the same reference numerals. Since the open shield method using the concrete box of the present invention is the same as the conventional example, detailed description is omitted.

  The concrete box 4 is made of reinforced concrete, and its basic structure is composed of a left side plate 4a, a right side plate 4b, an upper floor plate 4c, and a lower floor plate 4d as in the above-described conventional example. . In addition, the corners of the concrete box 4 have a haunch shape, and the concrete thickness is increased in order to increase the strength of the concrete box 4.

  A wide band-shaped composite cushioning member 15 is applied to the end face 4 e in the front-rear direction of the concrete box 4. As shown in FIG. 2, the composite cushioning member 15 is obtained by embedding a metal foil 15b as a non-stretchable sheet in a cushioning material 15a. The buffer material 15a is made of a resin that does not easily corrode, and is made of a material having a small Poisson's ratio and a wide plastic region against stress.

  The cushioning material 15a may be embedded in a non-stretchable sheet shape, and a face cloth may be used instead of the metal foil 15b.

  Further, as shown in FIG. 3, the composite cushioning member 15 may be configured by sandwiching a highly elastic rubber 15c between the cushioning materials 15a. By doing in this way, the adhesiveness to the end surface 4e of the composite buffer member 15 further improves by the resilience of the rubber 15c.

  Further, the composite buffer member 15 forms a groove 19 with a space therebetween, and a string-like seal material 16 is disposed in the groove 19 and is attached to the end surface 4e, whereby the composite buffer member 15 and the seal material are disposed. And in parallel.

  By forming the groove 19 in this way, the sealing material 16 can be easily positioned and can be disposed in a stable state. As such a string-like sealing material 16, butyl rubber or water-swellable rubber is suitable.

  The band-shaped composite cushioning member 15 and the sealing material 16 are previously attached to the concrete box 4 before being embedded with an adhesive or bolts.

  Similarly to the conventional example, the corner corner haunch 4f of the end surface 4e of the concrete box 4 is also provided with a sheath hole 12 for inserting a PC steel rod for fastening the concrete boxes 4 to each other. The portion to be positioned is not covered with the composite buffer member 15 or the sealing material 16.

  When the concrete boxes 4 configured in this way are arranged in a column in the ground, the concrete boxes 4 are joined to each other via the composite buffer member 15 and the sealing material 16.

  If the composite buffer member 15 is attached only to either one of the front and rear end faces 4e of the concrete box 4, the other one without the composite buffer member 15 of the other concrete box 4 when arranged in a column. The end face 4e of this is in contact with this.

  Further, the composite buffer member 15 may be provided on both the front and rear end surfaces 4 e of the concrete box 4. In this case, only the composite buffer member 15 is attached to any one of the end surfaces 4e, and the sealing material 16 is not provided.

  The concrete box 4 is sequentially embedded in the same manner as in the prior art by appropriately repeating the soil removal process by the excavator, the forward process of the open shield machine, and the setting process of the concrete box 4 in order. 4 is left in the ground in the vertical as the open shield machine advances. The remaining concrete box 4 is arranged by passing a fastening member such as a PC steel rod through the sheath hole 12 and sequentially tightening and fastening.

  When the open shield machine moves forward with a reaction force applied to the concrete box 4 during the curve construction, the propulsion reaction force is applied non-uniformly to the joint surface of the concrete box 4, but the composite buffer member 15 adheres to the end face 4e. Thus, the thrust is uniformly transmitted to the end face 4e by being interposed in the connecting portion of the concrete box 4.

  That is, since the composite cushioning member 15 is configured using the cushioning material 15a made of a material having a wide plastic region against stress, the composite cushioning member 15 compressed by the propulsion reaction force is deformed flexibly in the compression direction, and the concrete box It adheres firmly to the end surface 4e which is a connection part of four.

  And since this composite buffer member 15 was made to adhere widely to the end face 4e in the front-rear direction of the concrete box 4, the thrust is applied to the end face 4e of the concrete box 4 unevenly, or the end face of the concrete box 4 Even if unevenness exists in 4e, the composite cushioning member 15 is in close contact with the end surface 4e of the concrete box 4 to transmit the thrust uniformly and prevent the concrete boxes 4 from being displaced, and the concrete box The unevenness of the end surface 4e of the body 4 can be absorbed, and the point touch at the joint portion of the concrete box 4 can be prevented to prevent the concrete from being damaged.

  Since the buffer material 15a is made of a material having a small Poisson's ratio that is difficult to spread even under stress, and the metal foil 15b is embedded in the material as a non-stretchable sheet, the composite buffer member 15 is formed. The expansion in the width direction is restricted by 15b, and the cushioning material 15a itself is also difficult to spread by compression. Even if this composite cushioning member 15 is widely applied to the end face 4e in the front-rear direction of the concrete box 4, the propulsion jack 2 The composite buffer member 15 compressed by the thrust does not protrude from the end face 4e of the connecting portion of the concrete box 4.

  That is, the damage of the composite cushioning member 15 proceeds from the portion that protrudes from the end face 4e of the connecting portion of the concrete box 4, thereby preventing the slippage of the concrete boxes 4 and preventing the concrete damage with time. It will not be lost.

  Further, since the sealing material 16 is attached to the end face 4e of the concrete box 4 in parallel with the composite buffer member 15, in addition to the buffering action by the composite buffer member 15, the concrete box 4 by the sealing material 16 is used. It is also possible to obtain a water-stopping action at the connecting portion. That is, the sealing material 16 is compressed between the concrete boxes 4 and exhibits a water stop effect.

  Since the connecting portion of the concrete box 4 is protected by the composite buffer member 15 that is not easily corroded or damaged, the sealing material 16 disposed at the connecting portion of the concrete box 4 is also protected by the composite buffer member 15. Thus, the water stop action can be maintained.

  In any of the embodiments, the case where the concrete box 4 is used in the open shield method has been described. However, the concrete box of the present invention is also applicable to the propulsion method.

It is a whole perspective view which shows 1st Embodiment of the concrete box of this invention. It is a vertical side view which shows a composite buffer member. It is a vertical side view which shows the concrete box end surface which adhered the composite buffer member and the sealing material. It is a vertical side view which shows the outline of an open shield construction method. It is a perspective view of the conventional concrete box. It is a top view which shows a mode that the force which produces the shift | offset | difference acts on the junction part of a concrete box by the curve construction of an open shield method.

DESCRIPTION OF SYMBOLS 1 Open shield machine 1a Side wall board 1b Bottom board 1c Tail part 2 Propulsion jack 3 Bulkhead 4 Concrete box 4a Left side board 4b Right side board 4c Upper floor board 4d Lower floor board 4e End face 4f Corner corner haunch part 5 Backfill soil 6 Grout material
7 Height adjusting material 8 Press bar 9 Excavator 10 Opening 11 Blade opening 12 Sheath hole 15 Composite buffer member 15a Buffer material 15b Metal foil 15c Rubber 16 Sealing material 17 Box removal 18 Butyl rubber 19 Groove 22 Buffer material

Claims (1)

It arranged sequentially in cascade for the underground, in concrete a box body for receiving the thrust of propulsion jacks, having elasticity in a strip of cushioning material according to the material made of non-stretchable embedded sheet resin to a metal foil or face cloth A composite shock-absorbing member is sandwiched between rubber, and this composite shock-absorbing member is widely applied to the front and rear end faces of the box, and the sealing material is attached to the box end face in parallel with the composite shock-absorbing member. A concrete box.

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