JP4598728B2 - 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 earth removal process, advance 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 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 against the concrete box 4, an unbalanced force is applied to the concrete box 4 with the left and right propulsion jacks 2. Or, as shown by the alternate long and short dash line, the open shield machine 1 is tilted with respect to the concrete box 4, so the force applied to the top concrete box 4 is not equal to the end surface, but eccentric thrust acts, A shift occurs between the joining end surfaces of the concrete boxes 4 that are in tandem.

  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, but even in the case of straight construction, the concrete box 4 can be rolled by rolling or pitching the open shield machine 1. The force applied to the end face 4e is biased, causing the joint surface of the concrete box 4 to shift.

  As a method for preventing such deviation, for example, as shown in FIG. 5, an insertion hole 13 is formed in the end face 4e of the concrete box 4, and a pin is inserted therein to connect the concrete boxes 4 to each other. A method of fixing the end faces can also be considered.

  In addition, the device of the countermeasure against such a shift | offset | difference between the concrete boxes 4 is not made conventionally, and there is no patent document related to it.

  In the coupling method using the pin, when the bending degree of the construction site is large, the component force applied to the joint end surface of the concrete box 4 increases, and the pin deforms without being able to withstand the component force, and the insertion hole 13 The surrounding concrete may be chipped, and there is a risk of misalignment between the concrete boxes.

  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, there is no thrust on the joint end face of the concrete box, such as curved construction. An object of the present invention is to provide a concrete box that can surely prevent displacement between the concrete boxes when uniformly applied.

In order to achieve the above-mentioned object, the present invention is a concrete box made of reinforced concrete, comprising a left side plate, a right side plate, an upper floor plate and a lower floor plate, with the front and rear surfaces opened as openings. In a concrete box that is lined up and receives the thrust of a propulsion jack, a sheath hole for inserting a binding member such as a steel rod that binds the concrete boxes to each other is located at the corner haunch on the front and rear end faces of the box. As shown in the figure, a circular convex part is integrally formed, and a sheath hole for inserting a fastening member such as a steel rod for fastening concrete boxes together is formed in the center of the corner corner haunch part at the end face of an adjacent box. A circular concave portion that fits into the convex portion is formed so as to be positioned, the concave portion and the convex portion are circular, and an irregularity is provided in advance in a mold of the concrete box, and a concrete box is formed using this mold. Body It was created at the same time as the production of the concrete box, and was made integrally with the concrete box body. The convex part was a tapered trapezoid, and the depth of the concave part and the height of the convex part were circular. The gist of the invention is to prevent the mutual displacement of the boxes by fitting these convex portions and concave portions.

  According to this invention of Claim 1, the convex part provided in a concrete box end surface fits the recessed part of an adjacent concrete box, and can prevent the gap | deviation of concrete boxes. And since this convex part is formed integrally with the end face of the concrete box, it causes displacement at the joint part of the concrete box compared to the case where a thin pin etc., which is a separate member from the concrete box, is used. It can endure reliably by the force which tries. Therefore, especially in the curve construction in which thrust is applied nonuniformly to the joint end face of the concrete box, it is possible to reliably prevent the gap between the concrete boxes. Moreover, since the convex part is integrally formed on the end face of the concrete box, the convex part can be created at the same time when the concrete box is manufactured by the mold, so that it does not take time and effort.

  Since the concave portion and the convex portion are circular, the side surface of the convex portion draws a smooth arc, and it is possible to prevent external force from being locally applied to a part of the side surface of the convex portion. Since the height is set to be less than the radius of the circle, the force is applied locally like a thin pin, and the chipping of the concrete does not occur, and the displacement between the concrete boxes can be prevented more reliably. it can.

  In addition, the shape of the concave and convex portions is circular in cross section, so there is no need to consider the fitting direction during installation, and the depth of the concave portion and the height of the convex portion are set to be lower than the radius of the circle. Therefore, it is easier to fit than inserting a pin into a thin insertion hole, and does not hinder the concrete box when it is installed sequentially.

  In order to maintain the strength of the concrete box, the thickness of the concrete at the corners is thick. However, since the recesses and protrusions are provided on the corner corners of the concrete box, the recesses and protrusions are A sufficient space can be secured, and the sufficiently large uneven portion can more reliably oppose the component force applied in the horizontal direction of the end face of the concrete box.

  Since the shape of the convex portion is a tapered trapezoid, the strength of the convex portion with respect to external force is increased by a stable shape that becomes thicker toward the root. That is, the proof strength of the convex part with respect to the force which is going to raise | generate a shift | offset | difference in a concrete box end surface increases, and it can prevent more reliably the shift | offset | difference between concrete boxes.

  Further, the tapered trapezoidal shape provides a punching taper as a mold, and is suitable for forming a convex portion at the same time when a concrete box is produced by the mold.

  Furthermore, by making the convex part into a trapezoidal shape, when the concrete boxes are joined together, the fitting between the concave part and the convex part becomes easier, and the concrete box can be installed smoothly.

  By the way, in order to stably support the force to cause the displacement between the concrete boxes, it is necessary to increase the diameter of the convex portion and ensure a certain height. When the convex portion is trapezoidal, there may be a case where the height cannot be secured so much with respect to the width of the bottom area, but according to the present invention, even in such a case, the shape of the convex portion is circular. By making it columnar, the height can be secured regardless of the width of the bottom area.

  In addition, although the intensity | strength with respect to an external force becomes low compared with the case where it makes trapezoid shape by making the shape of a convex part into a trapezoid shape, sufficient intensity | strength is securable by covering this circumference | surroundings with steel materials. Since the base of the steel material is embedded in the end face of the concrete box, the steel material will not fall out.

  Further, by making the tip portion of the convex portion a chamfered shape, when the concrete boxes are joined together, the concave portion and the convex portion can be easily fitted, and the concrete box can be installed smoothly.

  Since the convex portion and the concave portion are provided so that the sheath hole for inserting a binding member such as a steel rod for binding the concrete boxes to each other is located in the center, the concave portion and the convex portion Without being hindered, the synergistic effect of the tightening by the tightening member and the fitting of the concave portion and the convex portion makes the bonding between the concrete boxes stronger and can prevent the displacement more reliably.

  If the formation angle of the concave and convex parts with respect to the end face of the concrete box is made to follow the row direction of the concrete boxes that are sequentially embedded, the thrust of the advance jack will be applied from the front of the convex part, and the side surface of the convex part Therefore, it is possible to more stably oppose the force to cause the displacement of the concrete boxes.

  If the concrete box has an end face that is inclined to the left and right, the end face of the concrete box can be made to follow the direction of receiving the thrust of the propulsion jack. Thereby, the bias | biasing of the thrust added to a box end surface is reduced, and the shift | offset | difference of a concrete box can be prevented more reliably.

  As described above, the concrete box of the present invention can surely prevent the gap between the concrete boxes when the thrust is applied unevenly to the joint end face of the concrete box, such as curve construction.

  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 40 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. .

  The corners of the concrete box 40 have a haunch shape and the concrete thickness is increased to increase the strength of the concrete box 40. The convex part 15 having a circular trapezoidal cross section is swelled in the corner corner haunch part 4f of the end face 4e. I made it out. Further, the other end face 4e of the concrete box 40 is provided with a concave part 14 that fits the convex part 15 at a position corresponding to the convex part 15 of the adjacent concrete box 40 when the concrete box 40 is arranged in a row. Provided.

  The convex portions 15 and the concave portions 14 are formed at the same time as the concrete box 40 is manufactured, for example, by providing irregularities on the mold of the concrete box 40 in advance and manufacturing the concrete box 40 using the mold. In addition, the convex portion 15 can be formed integrally with the concrete box 40 main body.

  The corner corner haunch 4f of the end face 4e of the concrete box 40 is also provided with a sheath hole 12 for inserting a PC steel rod as a fastening member for fastening the concrete box 40 together. The formation position of the concave portion 14 and the convex portion 15 is set so as to be at the center of the portion 15 or in the vicinity thereof. In the figure, reference numeral 17 indicates the removal of the PC steel rod wearing box.

  As shown in FIG. 2, the circular trapezoidal convex portion 15 has a height L2 that is less than or equal to half the diameter L1 of the top surface 15a having the smallest cross-sectional area.

  The concrete box 40 is sequentially embedded in the same manner as in the prior art by appropriately repeating the soil removal process by the excavator, the advance process of the open shield machine, and the setting process of the concrete box 40, and sequentially. 40 is left in the ground in a column as the open shield machine advances.

  And when installing the next concrete box 40 in front of the concrete box 40 previously installed in the ground, the convex part 15 and the concave part 14 provided on each end face 4e are fitted together. Install. Since the convex portion 15 has a circular trapezoidal shape, the fitting is easy, and the installation work is not hindered.

  Thereafter, the PC steel bar is attached in the boxing box 17 and is tightly connected to strengthen the connection between the concrete boxes 40.

  When the open shield machine makes a curve and moves forward with a reaction force applied to the concrete box 40, a force is applied to cause a deviation at the joint surface of the concrete box 40, but the convex portion 15 is cut off as it goes to the root. It has a trapezoidal shape with a large area and can stably withstand external force applied to the joint portion of the concrete box 40.

  Furthermore, since the tightening force by the PC steel rod is also applied at the central portion of the concave portion 14 and the convex portion 15, it is possible to prevent the displacement of the joint surface of the concrete box 40 more reliably.

  In addition, the convex portion 15 has a trapezoidal shape with a larger cross-sectional area as it goes to the base, and its height L3 is equal to or less than half of the diameter of the top surface 15a. There is no occurrence of chipping in concrete due to external force applied locally like a pin.

  As shown in FIG. 3 as the second embodiment, the convex portion 16 may be formed in a columnar shape or a conical column shape instead of a circular trapezoidal shape. Also in the case of manufacturing such a concrete box 40, as in the first embodiment, the positions of the convex portions 16 and the concave portions (not shown) correspond to the corner corner haunch portions 4f of the end surface 4e. However, the shape of the convex portion 16 is a cylindrical shape with a chamfered tip portion.

  As in the first embodiment, the convex portion 16 and the concave portion are created at the same time when the concrete box 40 is manufactured by the mold, but the convex portion 16 is covered with a steel material as described later. In consideration of the configuration, the diameter of the mold of the convex portion 16 is set smaller than the diameter of the concave portion by the thickness, and a groove for embedding the base of the steel material is provided on the end surface 4e.

  The convex portion 16 covers the periphery of a columnar concrete core portion 18 whose end portion is chamfered with a steel cylinder 19 made of a steel material, and the base of the steel cylinder 19 is fitted into the groove of the end face 4e of the concrete box 40. And then embed. The steel cylinder 19 is formed integrally with the concrete box 40 and reinforces the concrete core 18 that resists external force.

  As an example, the convex portion 16 as a whole is formed into a columnar shape, the tip portion is chamfered to form a tapered surface 16d, and the height of the cylindrical portion side surface 16c from the lower end of the steel cylinder 19 to the tapered surface 16d is increased. The length L3 is not more than half of the diameter L4 of the cylindrical portion.

  As in the conventional example, the corner hole haunch 4f of the end face 4e of the concrete box 40 is also provided with a sheath hole 12 for inserting a PC steel rod for fastening the concrete boxes 40 to each other. It is assumed that the protruding position of the convex portion 16 is set so that is at the center of the convex portion 16 or in the vicinity thereof.

  The method of installing the concrete box 40 provided with such convex portions 16 is the same as that of the first embodiment, and the next concrete box 40 is installed in front of the concrete box 40 previously installed in the ground. At this time, the protrusions 15 and the recesses provided on the end surfaces 4e are fitted to each other. Since the convex portion 16 is a tapered surface 16d having a chamfered tip, fitting is easy and does not hinder the installation work.

  Thereafter, the PC steel bar is attached in the boxing box 17 and is tightly connected to strengthen the connection between the concrete boxes 40.

  When the open shield machine is curved and moves forward with a reaction force applied to the concrete box 40, a force is applied to cause a deviation at the joint surface of the concrete box 40, but the height of the convex portion 16 is L3. In addition to being a stable shape that is less than half the diameter L4 of the cylindrical portion, it is reinforced by a steel cylinder 19, and the base of the steel cylinder 19 is embedded in the end face 4e of the concrete box 40 to increase stability. Therefore, it can withstand the external force applied to the joint portion of the concrete box 40 stably.

  Furthermore, since the binding force by the PC steel rod is also applied at the central portion of the convex portion 16, it is possible to prevent the displacement of the joint surface of the concrete box 40 more reliably.

  In the embodiment, the convex portions 15 are provided at the four corners of the end surface 4e on one side of the concrete box 40 and the concave portions 14 are provided at the four corners of the other end surface 4e. However, the concave portion 14 and the convex portion are provided on one end surface 4e. The unit 15 may be mixed. Further, together with the fitting by the concave portion 14 and the convex portion 15, an insertion hole similar to the conventional example may be formed at an appropriate location on the end face 4e to insert a pin.

  Although not shown in the drawings, as a third embodiment of the concrete box 40 of the present invention, the projecting angle of the convex portion on the end surface 4e of the concrete box 40 is set in the row direction of the concrete boxes 40 that are sequentially embedded. You may make it follow.

  In this case, the reaction force when propelled by the open shield machine is applied from the front surface of the convex portion, and an excessive load is not applied to the side surface of the convex portion, and an attempt is made to cause displacement between the concrete boxes 40. It is possible to face the force more stably.

  The angle of such a convex part and the concave part corresponding to it with respect to the end surface 4e of the concrete box 40 differs for each concrete box 40. Therefore, when manufacturing the concrete box 40, it is preferable to manufacture the end surface 4e of the adjacent concrete box 40 as a wife formwork.

  In this case, it is preferable to apply a release agent or install a sheet on the end face 4e used as the end form to prevent the cast concrete from being joined.

  Furthermore, as a fourth embodiment of the concrete box 40 of the present invention, the concrete box 40 may have an end face 4e that is inclined to the left and right, as shown by a one-dot chain line in FIG.

  Thereby, the direction of the end surface 4e can follow the construction curve, and the bias of the reaction force when the open shield machine propels the end surface 4e is reduced. In addition to preventing the displacement of the concrete box 40 due to the fitting, the displacement of the concrete box 40 can be more reliably prevented.

  Furthermore, the convex portion and the concave portion may be formed perpendicular to the inclined end face 4e. However, if the forming angle is made to follow the row direction of the concrete box to be embedded sequentially, the convex portion and the concave portion may be formed. Compared with the case where only one of the change of the forming angle of the portion and the concave portion and the provision of the inclination to the end surface 4e corresponds to the construction curve, a more stable detent effect can be obtained.

  In other words, at the place where the construction curve is a sharp curve, the formation angle of the convex portion and the concave portion with respect to the end surface 4e is sufficient if the inclination of the end surface 4e itself is subtracted, and the formation angle of the convex portion and the concave portion is the end surface 4e. There is no trouble such as making it difficult to fit each other by tilting to the extreme, and there is no unstable state where the base of the convex part is lifted. The effect of preventing misalignment can be sufficiently exhibited.

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 the convex part which is the principal part of 1st Embodiment of the concrete box of this invention. It is a vertical side view which shows the convex part which is the principal part of 2nd Embodiment of the concrete box of this invention. 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 6 Grout material 7 Height Adjusting material 8 Press bar 9 Excavator 10 Opening 11 Blade opening 12 Sheath hole 13 Insertion hole 14 Recess 15 Protruding portion 15a Top surface 16 Convex portion 16a Top surface 16b Bottom surface 16c Cylindrical side surface 16d Tapered surface 17 Box extraction 18 Concrete core 19 Steel cylinder 40 Concrete box

Claims (1)

A concrete box made of reinforced concrete, consisting of a left side plate, a right side plate, an upper floor plate, and a lower floor plate, with the front and rear surfaces open and arranged in tandem for underground use and receiving thrust from a propulsion jack In the box,
At the corner corner haunch part at the front and back end face of the box,
A circular convex part is integrally formed so that a sheath hole for inserting a binding member such as a steel rod that binds concrete boxes to each other is located in the center, and the corner corner haunch part at the end face of the adjacent box A circular recess is formed to fit into the convex portion so that a sheath hole for inserting a binding member such as a steel rod for binding concrete boxes to each other is located in the center, and the concave portion and the convex portion are circular. In addition, the concrete box was made uneven in advance, and the concrete box was made using this form, so it was created at the same time as the concrete box was made, and was made integrally with the concrete box body. The convex part has a tapered trapezoidal shape, the depth of the concave part and the height of the convex part are less than the radius of the circle, and the convex parts and concave parts are fitted to prevent mutual displacement of the boxes. A concrete box.

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