JP2018053465A - Flexible joint structure of concrete box body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible joint structure of a concrete box body which can be fastened and fixed by setting a fixation bolt easily for displacement prevention of the box bodies when a construction by an open shield method (at the time of installation of a box body) and can be a flexible joint when a reaction becomes unnecessary for the box body and by which a cut-off performance can be secured in any case.SOLUTION: A lock plate 26 with a key hoke 26a is installed in the back of a fixation bolt insertion hole 12 of one of concrete box bodies 4, a key projection 27 is disposed in one end of a fixation bolt 17, the key projection 27 put through the key hole 26a is locked to the lock plate 26 by insertion of the fixation bolt 17 into the fixation bolt insertion hole 12 and rotation, the other end of the fixation bolt 17 which enters the fixation bolt insertion hole 12 of the other concrete box body 4 is fitted with a fixation plate 21 and a buffer rubber ring 28 and locked with a nut 22 at a box-out 25 in the back of the fixation bolt insertion hole 12 and the surroundings are filled with shrinkage-compensating mortar 19.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flexible joint structure of a concrete box used in an open shield method for constructing underground structures such as water and sewage systems and underground passages in an urban area.

As for the flexible joint of a concrete box (box culvert), there is, for example, the following patent document.
JP-A-9-60099

  As shown in FIG. 15, the Patent Document 1 has a water stop plate 5 that can follow a displacement while maintaining a water stop effect at a connection portion of each box culvert 102 having a closed section having a space portion 102a in the center. Provide.

  The box culverts 102 are connected by a PC steel rod 106 which prevents damage when the design displacement amount of the water stop plate 105 is exceeded and which itself can follow the design displacement of the water stop plate 105.

  And the connection part 103 can follow a displacement so that the water stop state of each box culvert 102 can be maintained and the connection state can be maintained, and even if a displacement occurs in the connection state, To maintain the function of.

  Although not shown, the fixing of both ends of the PC steel rod 106 to the connecting end of the box culvert 102 is performed by a special fixing tool configured to maintain the fixing state following the displacement. The special fixing tool has a hemispherical shape in which a PC steel bar 106 passes through a central portion, and a fixing nut that is tightened to fix the PC steel bar 106 has a planar seating surface that abuts via an urging device 114. A washer and a base 113 for washer in which a concave surface portion into which the spherical surface portion of the hemispherical washer is fitted is formed in a substantially central portion, and a through hole through which the PC steel rod 106 is formed is formed in a substantially central portion; Consists of.

  Then, due to the action of the spherical surface portion of the hemispherical washer and the concave surface portion of the washer base 113 in this special fixing tool, the seating surface of the hemispherical washer with which the fixing nut abuts via the biasing device 114 is generated by displacement. The PC steel rod 106 can move following the change in the arrangement position.

  In addition, even when the seat surface of the hemispherical washer with which the fixing nut abuts moves as described above, the tightening force of the fixing nut can be maintained by the action of the urging device 114 incorporating the coil spring. .

  Next, an open shield method using the concrete box of the present invention will be described.

  The open shield method is a rational method that makes use of the advantages of the open cut method (open cut method) and the shield method, and is promoted using an upper open type shield machine (open shield machine) while preventing sediment collapse. This is a method of laying a box inside.

  16 and 17, the open shield machine 1 is a shield machine having left, right and left side wall plates and bottom plates connected to the side wall plates, with front, rear and top surfaces opened. .

  The open shield machine 1 is divided into a plurality of bodies in the front-rear direction, and the front end of the rear body as the tail portion 1b is fitted into the rear end of the front body as the front portion 1a. The middle bent portion 2 is formed to be bendable.

  The front part 1a is mainly used for excavation, and has a front end and an upper surface as open surfaces. Inside the machine body, the middle jacks are arranged on the left and right and rearward and rearward in a plurality of stages.

  On the other hand, the tail portion 1b is used to install the concrete box 4 and has a bottom plate 5, and the propulsion jack (shield jack) 3 is directed to the front and rear in the body, and is moved up and down. It is arranged in multiple stages.

  In the figure, 6 is a slide earth retaining plate provided at the front end of the front portion 1a, and 8 is a press bar (push angle).

  Next, an open shield construction method using such an open shield machine 1 will be described. Although illustration is omitted, the open shield machine 1 is installed in the start shaft and the propulsion jack 3 of the open shield machine 1 is extended. Then, the open shield machine 1 is moved forward by taking the reaction force against the reaction wall in the starting pit, and the first concrete box 4 forming the underground structure is suspended from above by a lifting machine 14 such as a crane, Set behind the propulsion jack 3 shrunk in the tail 1b of the open shield machine 1.

  The excavator 7 such as an excavator excavates and removes soil from the front or upper surface of the open shield machine 1. At the same time as or after this earth removal step, the propulsion jack 3 is extended to advance the open shield machine 1.

  Then, the second concrete box 4 is suspended in the tail portion 1 b 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. 4. Backfill the upper surface of 4.

  When the concrete box 4 is suspended in the tail part 1b 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 part 4 is placed inside the tail part 1b. Filling the backside injection material 9 using the instantaneous setting grout material in the left and right and lower gaps of the box 4 to perform the primary injection, and after the open shield machine 1 moves forward, as a secondary injection, the concrete box Back injection material 9 is injected from the inside of 4 to the outside by a grout hole.

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

  The concrete boxes 4 buried in a column in the ground in this way are fixed when a new concrete box 4 is suspended in the tail portion 1b of the open shield machine 1 with respect to the existing concrete box 4. The fixing portion 10 is formed as shown in FIG.

  The concrete boxes 4 forming the fixing unit 10 are connected to each other, although not shown in the drawings, through-holes in the front-rear direction are provided at the corners, and those arranged in tandem with bolts or the like are connected.

  In the open shield construction method, excavator such as an excavator excavates and removes soil from the front or top surface of the open shield machine, and the propulsion jack is extended at the same time or after this earth removal process to advance the open shield machine. Therefore, since the concrete box receives the reaction force of the jack thrust, it is required to be firmly fastened at the time of installation, and thereafter, the connection between the concrete boxes 4 is required to be a flexible joint.

  In Patent Document 1, since the box culvert receives the reaction force of the jack thrust, it is not taken into account that a firm fastening is required at the time of installation, and it is considered that the fastening is changed at the joint installation stage. Not.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and to take into consideration the special characteristics of the open shield method, fixing bolts are used to prevent the box and box from slipping during construction of the open shield method (when the box is installed). To provide a flexible joint structure of a concrete box that can be easily set, tightened and fixed, and can be used as a flexible joint by loosening the bolt fixing part when reaction force is no longer required on the box is there.

  In order to achieve the above object, the present invention according to claim 1 is characterized in that the fixing bolt insertion holes are formed by combining the fixing bolt insertion holes of one concrete box and the other concrete box with a cushion material interposed therebetween. In the flexible joint structure of a concrete box that is fastened with a fixing bolt, a lock plate with a key hole is installed at the back of the fixing bolt insertion hole of one concrete box, and a key projection is attached to one end of the fixing bolt. The fixing bolt is inserted into the fixing bolt insertion hole, and turned to lock the key projection through the key hole to the lock plate and enter the fixing bolt insertion hole of the other concrete box. The gist is that the fixing plate and the shock absorbing rubber ring are fitted and nuts are fixed by removing the box in the depth of the fixing bolt insertion hole, and the surroundings are filled with non-shrink mortar.

  According to the first aspect of the present invention, first, with respect to the set of fixing bolts, one end of the fixing bolt inserted into the fixing bolt insertion hole of one concrete box is inserted into the lock plate, and turned to turn the key hole. The other key of the fixing bolt can be locked with the lock plate, and the other end of the fixing bolt can be locked with the fixing plate and the shock absorbing rubber ring. Can be fixed and set easily.

  When installing the open shield method (when installing the box), the fixing bolt is tightened and fixed without using a buffer rubber ring to prevent the box and box from slipping even when the reaction force of the jack thrust is received. It can be carried out.

  Also, by fastening concrete boxes with fixing bolts, a cushioning material acts between the concrete boxes, and the so-called point touch where the cushioning material is only in partial contact with each other at the connecting portion of the concrete box. It is possible to prevent the possibility that the concrete will be damaged due to the stress concentrated on the contact portion due to the point touch when the jack thrust is lost.

  On the other hand, when the reaction force on the box is no longer needed, loosen the bolt fixing part, fix it with a cushioning material (rubber), and fill it with non-shrink mortar around the bolt end, so that the cushioning material can be used during an earthquake. A flexible joint that can follow the behavior of the concrete box by crushing (rubber) can be obtained.

  The present invention according to claim 2 is characterized in that a cushioning material made of hard rubber is coated at the center of the fixing bolt, and this cushioning material is straddled across the sheath holes of one concrete box and the other concrete box. It is what.

  According to the second aspect of the present invention, the fixing bolt is held horizontally so as to be displaceable in the sheath hole between the concrete boxes by the hard rubber cushioning material coated at the center.

  The gist of the present invention described in claim 3 is that the inner joints between the concrete boxes are filled with a two-component joint material.

  According to the third aspect of the present invention, regarding the water stoppage of the connecting portion of the concrete box, it becomes liquid after hardening in the coalesced joint groove formed between the concrete boxes and becomes elastic after hardening, and follows the movement of the joint. Water stoppage can be secured by filling the joint material.

  On the other hand, when the reaction force on the box is no longer needed, loosen the bolt fixing part, fix it with a cushioning material (rubber), and fill it with non-shrink mortar around the bolt end, so that the cushioning material can be used during an earthquake. A flexible joint that can follow the behavior of the concrete box by crushing (rubber) can be obtained.

  The joint material filled in the joint joint groove loosens the bolt fixing portion and extends even if the concrete box is displaced, and the water stoppage can be secured.

  The gist of the present invention described in claim 4 is that a sealing material is interposed between the joint end faces of the concrete boxes.

  According to the fourth aspect of the present invention, regarding the water stoppage of the connecting portion of the concrete box, the water stoppage can be ensured by the band-shaped sealing material affixed to the end face of the concrete box.

  On the other hand, when the reaction force on the box is no longer needed, the bolt fixing part can be loosened to make a flexible joint that can follow the behavior of the concrete box, in which case the seal material is somewhat loose in the collapsed state. Mutual pressure contact is maintained, and water blocking is ensured.

  As described above, the flexible joint structure of the concrete box of the present invention prevents the gap between the box and the box during the construction of the open shield method (when the box is installed) in consideration of the special characteristics of the open shield method. For this purpose, a fixing bolt can be easily set and tightened and fixed, and when a reaction force is no longer required on the box, the bolt fixing portion can be loosened to form a flexible joint.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a longitudinal sectional front view showing an embodiment of a flexible joint structure of a concrete box according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a sectional view taken along line BB in FIG. 4 is a cross-sectional view taken along the line CC of the above.

  The concrete box used in the open shield method of the present invention will be described with reference to FIG. 19. The concrete box 4 is made of reinforced concrete or PC concrete, and includes a left side plate 4a, a right side plate 4b, an upper floor plate 4c, and a bottom plate. It consists of a floor plate 4d, and the front and rear surfaces are opened as openings.

  Furthermore, the concrete box 4 is provided with fixing bolt insertion holes 12 for joining together (see FIG. 13).

  The depth of the fixing bolt insertion hole 12 of one concrete box 4 is a box opening 25 for forming a fixing portion. In the other concrete box 4, the depth of the fixing bolt insertion hole 12 is a notch hole. The lock part 26 was formed by partitioning with a lock plate 26b having a key hole 26a. The lock plate 26b is provided with a hole through which the fixing bolt 17 is inserted at the center, and the key hole 26a is formed as four notches in the cross direction around the key hole 26a.

  On the other hand, a key protrusion 27 that can be inserted into the key hole 26a is provided at one end of the fixing bolt 17 to be inserted into the fixing bolt insertion hole 12. The key protrusion 27 protrudes in the cross direction at the end of the fixing bolt 17.

  In order to make the key protrusion 27 easy to change, as shown in FIG. 14, when viewed from the side (a), the lower end of the tip is rounded 27a, and when viewed from the front (b), the left and right lower edges are rounded. 27a.

  A buffer material 18 made of hard rubber was coated on the center of the fixing bolt 17. The buffer material 18 is a ring through which the fixing bolt 17 passes.

  In the figure, 11 is a cushioning material such as rubber interposed between the concrete boxes 4, and 13 is a sealing material such as rubber packing.

  The cushion material 11 is a wide band plate that covers the end surfaces of the left side plate 4a and the right side plate 4b of the concrete box 4 along the vertical direction.

  The sealing material 13 is a belt-shaped sealing material having a rectangular cross section that is attached to a shallow groove extending in the circumferential direction formed on the end face of the concrete box 4 and has elastic compressibility.

  The outline of the open shield construction method is as described above with reference to FIGS. 16 and 18. The open shield machine 1 is installed in the start shaft, the propulsion jack 3 of the open shield machine 1 is extended, and the Taking the reaction force against the reaction wall, the open shield machine 1 is advanced, and the first concrete box 4 forming the underground structure is suspended from above by a lifting machine 14 such as a crane. Set behind the propulsion jack 3 shrunk in the tail 1b.

  The excavator 7 such as an excavator excavates and removes soil from the front or upper surface of the open shield machine 1. At the same time as or after this earth removal step, the propulsion jack 3 is extended to advance the open shield machine 1.

  Then, the second concrete box 4 is suspended in the tail portion 1 b 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. 4. Backfill the upper surface of 4.

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

  The open shield method of the present invention also suspends a new concrete box 4 from the tail part of an open shield machine and connects it to the existing concrete box 4 and guide pins (not shown) are inserted into the guide pin insertion holes 15 for positioning. Insert).

  The fixing bolt 17 is inserted into the fixing bolt insertion hole 12 as a metal fitting for preventing it from coming out, the tip of the fixing bolt 17 penetrates the lock plate 26b, and the fixing bolt 17 is turned to displace the key protrusion 27 from the key hole 26a. 17 is locked to the lock unit 26.

  The cushioning material 18 made of hard rubber covered at the center of the fixing bolt 17 is placed over the fixing bolt insertion holes 12 in both the one concrete box 4 and the other concrete box 4.

  Further, the other end of the fixing bolt 17 is fastened by a nut 22 with the fixing portion plate 21 interposed in the box opening 25.

  When the nut 22 is temporarily tightened, the cushion material 11 is sandwiched between the concrete boxes 4 and the seal material 13 is pressed in a crushed state. Thus, the concrete box 4 suspended as shown in FIG. It is fastened to the existing concrete box 4 with fixing bolts 17 and receives a driving reaction force by the jack of the open shield machine 1.

  When the excavation is finished and the reaction force is no longer necessary for the concrete box 4, the fixing bolt 17 is loosened in the box opening 25, and a buffer rubber ring 28 and a washer 29 are interposed in the fastening nut 22 of the fixing bolt 17 as shown in FIG. 6. The fixing bolt 17 is fixed, and the non-shrink mortar 19 is filled around the bolt end portion by the box opening 25 to form a flexible joint.

  Next, the displacement of the concrete box 4 at the time of an earthquake will be described. As shown in FIG. In some cases, opening and compression of the joints may occur, or in a disconnected state, opening may occur.

  In the detached state, as shown in FIG. 7, the concrete box 4 behaves so that the joints are opened, the fixing bolt 17 acts as a metal fitting to prevent it from coming out, and the buffer rubber ring 28 is deformed so as to be crushed. Follow changes in body 4.

  The same applies to the case of bending. As shown in FIG. 8, the concrete box 4 behaves so that the joints open, the fixing bolt 17 acts as a metal fitting to prevent the shock, and the shock absorbing rubber ring 28 is deformed to be crushed. Follow the changes in the concrete box 4.

  9 to 12 show a second embodiment of the present invention. Instead of disposing the sealing material 13, a backup material 23 is formed in a joint joint groove 20 formed when the concrete box 4 is connected. And the elastic joint material 24 is filled and sealed.

  As the elastic joint material 24, for example, two liquids of a modified silicone resin having elasticity and durability and an epoxy resin are mixed, become elastic after curing, follow the movement of the joint, and exhibit water-stopping properties. However, other joint materials may be used as long as they have adhesion to the joint portion and followability to the displacement of the concrete box during an earthquake after filling.

  As shown in FIG. 11 and FIG. 12, when the joint is opened or compressed in the joint of the concrete box 4 during the earthquake, or when the joint is pulled out and is opened, the elastic joint material is used at this time. No. 24 follows the gap even when the joint interval is widened, and continues water stopping.

  As the third embodiment, a combination of the first embodiment and the second embodiment, both the sealing material 13 and the elastic joint material 24 may be provided.

It is a vertical front view which shows 1st Embodiment of the flexible joint structure of the concrete box of this invention. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is 1st Embodiment of the flexible joint structure of the concrete box of this invention, and is a longitudinal front view of the front stage used as a flexible joint. It is 1st Embodiment of the flexible joint structure of the concrete box of this invention, and is a vertical front view of the state used as the flexible joint. In the first embodiment of the flexible joint structure of the concrete box of the present invention, the concrete box behaves so that the joints open, and is a longitudinal front view in the case where the box is pulled out and opens. It is 1st Embodiment of the flexible joint structure of the concrete box of this invention, a concrete box behaves so that a joint may open, and a vertical front view in case opening and compression arise. It is a 2nd embodiment of the flexible joint structure of the concrete box of the present invention, and it is a longitudinal front view of the previous stage made into a flexible joint. It is a longitudinal front view of the state made into the flexible joint in 2nd Embodiment of the flexible joint structure of the concrete box of this invention. In the second embodiment of the flexible joint structure of the concrete box of the present invention, the concrete box behaves so that the joints open, and is a longitudinal front view in the case where the box is pulled out and opens. In the second embodiment of the flexible joint structure of the concrete box of the present invention, the concrete boxes behave like open joints, and are longitudinal front views when opening and compression occur. It is a front view which shows the position of the fixing bolt insertion hole of the concrete box of this invention. It is explanatory drawing of a key protrusion. It is explanatory drawing which shows a prior art example. It is explanatory drawing at the time of box installation of an open shield construction method. It is explanatory drawing at the time of the box connection of an open shield construction method. It is a side view of the completed underground structure by the open shield method. It is a side view of a concrete box. It is explanatory drawing which shows the displacement of the concrete box at the time of an earthquake.

DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a ... Front part 1b ... Tail part 2 ... Folding part 3 ... Propulsion jack (shield jack)
4 ... Concrete box 4a ... Left side plate 4b ... Right side plate 4c ... Upper floor plate 4d ... Lower floor plate 5 ... Bottom plate 6 ... Slide retaining plate 7 ... Excavator 8 ... Press bar (push angle)
DESCRIPTION OF SYMBOLS 9 ... Back injection material 10 ... Fixing part 11 ... Cushion material 12 ... Fixing bolt insertion hole 13 ... Sealing material 14 ... Lifting machine 15 ... Guide pin insertion hole
DESCRIPTION OF SYMBOLS 17 ... Fixing bolt 18 ... Buffer material 19 ... Non-shrink mortar 20 ... Groove 21 ... Fixing part plate 22 ... Nut 23 ... Backup material 24 ... Elastic joint material 25 ... Box removal 26 ... Lock part 26a ... Key hole 26b ... Lock board 27 ... Key projection 28 ... Rubber ring 29 ... Washer

Claims (4)

A concrete joint flexible joint that fastens one concrete box with a cushioning material between the other and the other concrete box with the fixing bolt insertion holes on both sides and fastening the fixing bolts between the fixing bolt insertion holes In structure
Install a lock plate with a key hole at the back of the fixing bolt insertion hole of one concrete box, and provide a key projection at one end of the fixing bolt, insert the fixing bolt into the fixing bolt insertion hole, and turn it to Lock the key projection through the hole to the lock plate and enter the fixing bolt insertion hole of the other concrete box. At the other end of the fixing bolt, remove the box behind the fixing bolt insertion hole and fit the fixing plate and buffer rubber ring. A flexible joint structure of a concrete box characterized in that it is fastened with a nut and filled with non-shrink mortar around.   2. A flexible joint for a concrete box according to claim 1, wherein a buffer material made of hard rubber is coated at the center of the fixing bolt, and the buffer material is straddled across the sheath holes of one concrete box and the other concrete box. Construction.   The flexible joint structure of a concrete box according to claim 1 or 2, wherein the inner joint between the concrete boxes is filled with a two-component joint material.   The flexible joint structure of a concrete box according to claim 1 or 2, wherein a sealing material is interposed between joint end surfaces of the concrete boxes.

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