JP2012193577A - Reinforcing method of existent covering and reinforcing apparatus - Google Patents

Abstract

The present invention relates to a reinforcing method and a reinforcing device that reinforce an existing lining with a circular cross section from the inside, and there is no reinforcing unit that obstructs use in the lining after reinforcement, and the existing lining is effectively applied with force from the inside. A method and apparatus for reinforcing an existing lining, which can be applied to extrude the existing lining to the outside to mitigate its deformation, and can effectively reinforce the existing lining by applying an extrusion force to the ground via the existing lining. I will provide a.
A step of arranging a plurality of arc-shaped blocks 1 at intervals in the circumferential direction of the inner surface of an existing lining F having a circular cross section, and arranging jacks 3 within the intervals, each jack 3 projecting and spaced apart. A step of applying a circumferential axial force to the arc-shaped block 1 while spreading the gap, arranging a gap holding material for holding the widened gap in the gap, removing the jack 3 and replacing the jack reaction force with the gap holding material, Forming a reinforcing ring comprising a plurality of arc-shaped blocks 1 arranged in the circumferential direction and a plurality of spacing members.
[Selection] Figure 3

Description

  The present invention relates to an existing lining reinforcing method and a reinforcing device for reinforcing an existing lining of an underground tunnel from the inside thereof.

  In urban areas such as the Tokyo metropolitan area, there are trunk roads and railway lines between dense buildings, and depending on the location, the ground space is used by three-dimensional intersections of expressways, etc. It is almost impossible to find free space on the ground for new main roads and infrastructure facilities.

  Therefore, there is an underground tunnel such as a cave that contains underground passages, common grooves, water supply / drainage pipes, power cables, gas pipes, etc. It is being constructed.

  This underground tunnel occupies ground traffic and uses the excavation method that constructs the housing in the excavation space secured by the earth retaining support, and the excavator uses the excavator to create a relatively soft ground. Assembling the segments in a ring shape while supporting them, taking a reaction force against them, constructing a shield tunnel while digging the excavator, and, for example, by pushing a propulsion pipe from a propeller in a shaft into the ground There are a wide variety of construction methods, such as the propulsion method that connects them.

  By the way, the history of use of underground space is relatively old, and there are tunnels that have already been in service for several decades in urban areas. In such underground tunnels with a long service period, in addition to the aging of the components such as segments, the working load changes due to the construction of new tunnels in the surrounding ground and the fluctuation of the groundwater level. There are problems such as lack of water and excessive deformation to induce cracks and water leakage.

  Among underground tunnels that have been constructed for more than 20 years, there are existing tunnels where large deformation exceeding the allowable value has been observed. Although the main cause of such a large deformation is not clear, it has been speculated that one of the main factors is a change in the earth pressure due to redevelopment work in the surrounding ground and a long-term change in the groundwater level.

  In this way, there are a variety of methods for reinforcing existing linings that make up underground tunnels that require reinforcement, but among them, rigid columns are assembled in a cross or radial shape within the existing lining, and jacks are attached to the ends of the rigid columns, for example. There is a method to reinforce an existing tunnel which is provided and extended to push the existing lining to the outside (natural ground side). In this reinforcement method, in order to maintain the state of the existing lining whose deformation has been forcibly relaxed by the reaction force of the jack, the assembly of rigid columns assembled in a cross shape or the like is left in the existing lining. become.

  If the assembly of rigid pillars assembled in a cross shape or the like is left in the existing lining as described above, this is a big problem for the use in the existing lining and its usage mode is limited. Will occur.

  Therefore, Patent Document 1 prepares a large number of reinforcing segments obtained by dividing a reinforcing material having substantially the same shape as the inner periphery of an existing tunnel in the circumferential direction, and installs the reinforcing segments one by one from the lower stage and injects grout on the back surface. And the method of repeating this in the circumferential direction and also the axial direction of the existing lining is disclosed.

  According to this reinforcing method, the reinforcing segment ring built inside the existing lining does not become an obstacle to using the existing lining, so that the above problem can be solved.

  However, the reinforcing method disclosed in Patent Document 1 does not apply force to the existing lining as in the case of the rigid column assembly in which the reinforcing segment ring is assembled in the above-described cross shape or the like. Since the reinforcing segment ring is only indirectly provided through the grout, the deformation reduction effect of the existing lining is extremely low.

  Therefore, in addition to relieving the deformation of the existing lining and reducing the internal stress due to the deformation, it is not possible to recover the strength of the existing lining, and the deformation of the existing lining is further advanced by external force. In the event of breakage or the like, it is inevitable that external force needs to be supported only by the supplemental segment ring.

JP 2001-323792 A

  The present invention has been made in view of the above-described problems, and relates to a reinforcing method for reinforcing an existing lining having a circular or substantially circular cross section from the inside thereof, and there is also a reinforcing unit that obstructs use in the lining after reinforcement. Without applying force to the existing lining effectively from the inside and pushing the existing lining outward (radially outward) to ease the deformation, or pushing force to the ground via the existing lining It is an object of the present invention to provide a reinforcing method and a reinforcing device for an existing lining that can effectively reinforce the existing lining.

  In order to achieve the above-mentioned object, according to the method of reinforcing an existing lining according to the present invention, a plurality of arc-shaped blocks are arranged at intervals in the circumferential direction of the inner surface of an existing lining having a circular or substantially circular cross section in an underground tunnel. And a first step of arranging a jack within the interval, and a second step of applying a circumferential axial force to each arc-shaped block while extending a plurality of jacks to widen the interval between the arc-shaped blocks. A plurality of spacing members arranged at least in the circumferential direction by disposing a spacing member that holds the widened spacing in the plurality of spacings, removing the jack from the spacing and replacing the jack reaction force with the spacing member; And a third step of forming a reinforcing ring comprising a plurality of spacing members.

  The reinforcing method of the existing lining of the present invention is applied to the existing lining by generating a force in the axial direction using a shaft member such as a rigid column from the inside of the existing lining as in the prior art described above. Instead of the technical idea, a reinforcing ring that can generate an axial force in the circumferential direction on the inner surface of the existing lining, such as a circular cross section, is constructed, and the diameter is increased by applying an axial force to the reinforcing ring to reinforce it. It embodies a new technical idea that the existing lining is given a force that pushes it to the ground in the process of expanding the diameter of the ring.

  Here, the underground tunnel consisting of the existing lining to be reinforced is constructed by assembling a shield tunnel or propulsion pipe with the segment ring assembled in the circumferential direction and the tunnel axial direction (axial direction of the existing lining) in the tunnel axial direction. It covers tunnels such as propulsion tunnels in general, and includes all existing tunnels that are provided in underground passages, joint grooves, water supply / drainage pipes, power cables, gas pipes, etc.

  Furthermore, in the reinforcing method of the present invention, an underground tunnel (existing lining) to be reinforced has a circular or substantially circular cross section (an ellipse, a shape having different curvatures in the upper half and the lower half, etc.). Yes. The reason is that the reinforcing method of the present invention applies axial force to the plurality of arc-shaped blocks constituting the reinforcing ring by the extension of jacks arranged between adjacent arc-shaped blocks, and the radial direction by the circumferential axial force. This is because a force in the (or normal direction) is generated and applied to the existing lining.

  In the first step, a plurality of arc-shaped blocks are arranged at intervals in the circumferential direction of the inner surface of the existing lining, and jacks are arranged within the intervals. For example, using a temporary receiving carriage equipped with an erector device that self-propels in the existing lining, a plurality of arc-shaped blocks are temporarily received at predetermined intervals in the circumferential direction of the existing lining, and further, within each interval Arrange a jack and provisionally.

  Here, the “arc-shaped block” is a concrete segment or steel segment having a predetermined width in the longitudinal direction of the existing lining, a predetermined thickness, and further forming a partial arc of the reinforcing ring. It is a member having a predetermined rigidity as a so-called secondary lining material.

  When a plurality of arc-shaped blocks and jacks are assembled and provisionally received in the circumferential direction of the existing lining, each jack is synchronously controlled as a second step to apply the same axial force to the corresponding left and right arc-shaped blocks.

  When a certain axial force is introduced, the plurality of arc-shaped blocks and jacks can form a ring shape independently without provisional support, and at this stage, the provisional support by the elector device or the like is released. At this stage, an intermediate reinforcing ring that is a front stage of the reinforcing ring is formed.

  By gradually increasing the protruding amount of each jack, the interval between the arc-shaped blocks increases, and the intermediate reinforcing ring expands in the process of increasing each interval in synchronization.

  As the diameter of the intermediate reinforcing ring is increased, a radial force due to the axial force of the intermediate reinforcing ring acts on the existing lining, and the existing lining is pushed to the natural ground by this force. Therefore, when a part of the existing lining is deformed inward, this deformation can be pushed out to the natural ground side to mitigate the deformation, and this deformation reduces the internal stress generated in the existing lining. It is possible to restore the proof strength of the existing lining.

  In terms of structural mechanics, when an equally distributed load (q) is applied to the existing lining with a circular cross section (radius r) from the ground, the surrounding lining of the existing lining is affected by this evenly distributed load. The axial force N (compression force) generated in the direction is obtained by the equation N = qr.

  Therefore, when the axial force N ′ is increased while expanding the diameter of the intermediate reinforcing ring, the distribution is equally distributed according to the axial force N ′ and the cross section (radius r ′) of the intermediate reinforcing ring at that time from the above calculation formula. The load q ′ can be applied from the intermediate reinforcing ring to the existing lining, and further, the ground can be applied in the direction of pushing out the natural ground from the existing lining (the direction of pushing back). That is, in this case, the earth pressure or earth water pressure acting on the existing lining from the natural ground is offset by the pushing force applied to the existing lining from the intermediate reinforcing ring.

  In addition, when the load such as earth pressure and earth water pressure acting on the existing lining increases in the future, the strength was restored by the reinforcing ring (having the initial proof strength) and the existing lining and the reinforcing ring. It is also possible to resist the load as a laminated beam consisting of

  Once the intermediate reinforcing ring has been expanded to a predetermined diameter, as a third step, an interval holding material that holds this interval is inserted with respect to the interval at which the jack is arranged, and the jack reaction force is exchanged with this. By removing from the interval, it is possible to form a reinforcing ring comprising at least a plurality of arc-shaped blocks arranged in the circumferential direction and a plurality of interval holding members.

  Here, of the arc-shaped blocks, an end surface facing an adjacent arc-shaped block has a tapered surface inclined from the existing tunnel side to the tunnel inner side, and the interval is a cross-sectional view extending to the tunnel inner side by two tapered surfaces on both sides thereof. It preferably has a trapezoidal shape, and the spacing member is preferably a first wedge having a trapezoidal cross-sectional shape that is the same as the spacing.

  By setting the end face of the arc-shaped block as a tapered surface and the cross-sectional shape of the interval between the arc-shaped blocks as a trapezoidal shape extending inside the tunnel, a trapezoidal interval holding material can be easily inserted into the interval. In addition, after the insertion, the spacing member becomes a wedge (first wedge), and it is possible to ensure the posture maintenance of the arc-shaped blocks in which the axial force is generated.

  In addition to simply inserting the spacing member into the spacing between the arc-shaped blocks, the spacing member may be fastened with a bolt or the like straddling the end surface of the arc-shaped block and the spacing member after insertion.

  Further, an embodiment may be provided in which an angle adjusting insertion tool is disposed between the tapered surface of the arc-shaped block and the jack, and the jack presses the flat surface of the angle adjusting insertion tool.

  Since the end surface of the arc-shaped block is a tapered surface, the pushing force from the jack is not effectively transmitted to the arc-shaped block by the method in which the pushing surface of the jack directly acts on the tapered surface.

  Therefore, an angle adjusting insertion tool is provided between the end surface of the arc-shaped block and the jack so that the jack can push the end surface of the arc-shaped block in the arc direction of the arc-shaped block, and a flat surface (along the arc direction of the arc-shaped block). A surface orthogonal to the direction) is formed, and the jack is pushed out of the flat surface of the angle adjusting insertion tool, whereby the pushing force of the jack can be effectively applied to the arc-shaped block. In addition, when removing a jack at a 3rd step, this insertion tool for angle adjustment will also be removed.

  Further, in the first step, the jack is disposed at a substantially central position of the end surface of the arc-shaped block, and in the third step, the spacing member is disposed on both sides of the jack at the end surface. Form may be sufficient.

  When the jack reaction force is transferred to the spacing member, the central position of the end face is pushed out with a jack so that the axial force does not act on only one eccentric position on the end surface of the arc-shaped block. By arranging it at two locations on the both sides of the jack (the same offset position on the left and right from the center position), there will be no uneven load acting on the arc-shaped block when the jack is pushed out, and the jack reaction force will be received by the spacing retaining material. There is no possibility that an unbalanced load acts on the arc-shaped block after the replacement.

  Further, in the third step, it is preferable to perform a stuffing process between the two spacing members after removing the jack.

  By filling and hardening grout (mortar, cement paste, etc.) in the gap defined by the end face of the opposing arc-shaped block and the two spacing members, a stiffening ring is made stronger in the circumferential direction. Can be formed.

  Moreover, the embodiment with which the buffer layer is provided in the outer surface which contacts an existing lining among the said arc-shaped blocks may be sufficient.

  A buffer layer made of a relatively elastic rubber resin sheet or a layer formed by applying a resin solvent is provided on the outer surface of the arc-shaped block in contact with the existing lining. Even when the inner surface of the lining is deteriorated and uneven, the unevenness is absorbed by the buffer layer, and the pushing force from the reinforcing ring to the existing lining can be adjusted substantially uniformly. Further, the reinforcing ring can be prevented from being damaged by the unevenness of the existing lining surface. In addition, the arc-shaped block is disposed in a perfect circle near the inner surface of the existing lining, and a buffer layer is formed by interposing a buffer material between the perfect circle made of the arc-shaped block and the existing lining. You can also.

  Further, in another embodiment of the method for reinforcing an existing lining according to the present invention, the reinforcing ring is disposed at an interval in the axial direction of the existing lining, and two adjacent reinforcing rings are opposed to each other. The end faces in the axial direction of the two arc-shaped blocks are also tapered surfaces, whereby the axial interval has a plan-view trapezoidal shape, and the second wedge having the plan-view trapezoidal shape within the axial interval. Is to be arranged.

  There are various types of reinforcement of the existing lining, and all the extended sections are reinforced with a continuous circumferential reinforcing ring, and multiple reinforcement rings are attached only to the sections where the existing lining is markedly deteriorated. There is a form in which reinforcement is performed by connecting in the direction, and a form in which a particularly marked deterioration is reinforced with only one relatively wide reinforcing ring.

  For example, this embodiment is intended for the case where a plurality of reinforcing rings are continuously constructed in the axial direction of an existing lining to reinforce an arbitrary extension section, and between arc-shaped blocks that constitute a circumferential reinforcing ring The end surfaces of the corresponding arc-shaped blocks between the adjacent reinforcing rings are tapered in the same manner as the trapezoidal first wedge (spacer holding member) is disposed here. A trapezoidal space is formed between the reinforcing rings, and a second wedge having the same shape as the trapezoidal space is arranged to firmly connect the reinforcing rings.

  In addition, the form which forms the end surface of the two arc-shaped blocks which an adjacent reinforcement ring opposes in a taper shape is an end surface of an arc-shaped block showing a taper shape by planar view which looked at the reinforcement ring from the tunnel inner side, and 2nd Similarly, the wedge also has a trapezoidal shape when seen from the inside of the tunnel.

  Similarly to the circumferential reinforcing ring, the two second wedges are arranged on the tapered surfaces of the arc-shaped blocks facing each other with the axial interval therebetween, and the gap between the two second wedges is arranged. The embodiment which performs a filling process may be sufficient.

  Further, the present invention extends to a reinforcing device for an existing lining, and this reinforcing device is disposed at intervals in the circumferential direction of the inner surface of the existing lining having a circular or substantially circular cross section in the underground tunnel. A plurality of arc-shaped blocks, and jacks arranged in each of the intervals, and extending a plurality of jacks to widen the interval between the arc-shaped blocks, and thereby generating a circumferential axial force on each arc-shaped block. A jack to be applied, and a spacing member that is arranged in the widened interval to maintain the spacing, and the spacing retaining material replaces the jack reaction force when the jack is removed from the spacing, A reinforcing ring comprising a plurality of arc-shaped blocks arranged at least in the circumferential direction and a plurality of spacing members is formed.

  The existing lining reinforcing device of the present invention is also a reinforcing structure composed of structural members applied in the existing lining reinforcing method described above, and has an arc shape in which an axial force is applied by a jack that is removed and does not exist in the final structure. A reinforcing ring made up of blocks and spacing members is used as the final device structure.

  In this reinforcing device, of the arc-shaped blocks, an end surface facing an adjacent arc-shaped block has a tapered surface inclined from the existing tunnel side to the tunnel inner side, and the interval is formed inside the tunnel by two tapered surfaces on both sides thereof. An embodiment in which the shape of a trapezoidal cross section is widened, and the spacing member is a first wedge having a trapezoidal cross section that is the same as the spacing may be used.

  Moreover, the embodiment with which the buffer layer is provided in the outer surface which contacts an existing lining among the said arc-shaped blocks may be sufficient.

  Further, the reinforcing ring is disposed at an interval in the axial direction of the existing lining, and the axial end surfaces of the two arc-shaped blocks facing each other adjacent reinforcing rings are also tapered surfaces, Accordingly, the axial interval may have a trapezoidal shape in plan view, and the second wedge having the trapezoidal shape in plan view may be disposed within the axial interval.

  As can be understood from the above description, according to the reinforcing method and the reinforcing device of the existing lining of the present invention, a reinforcing ring capable of generating an axial force in the circumferential direction on the inner surface of the existing lining having a circular cross section or the like is constructed. Then, by applying an axial force to the reinforcement ring and expanding its diameter, the reinforcement ring can be used inside the existing lining by applying a force to the existing lining in the process of expanding the diameter of the reinforcement ring. Earth pressure and soil water pressure that effectively act on the existing lining while not obstructing the above and reducing the internal stress by forcibly relieving the deformation of the existing lining and reducing its internal stress. Can be offset by the pushing force from the reinforcing ring.

It is a perspective view of one embodiment of an arc block. It is a schematic diagram explaining the 1st step of the reinforcement method of the existing lining of this invention. FIG. 3 is a schematic diagram for explaining the first step and further the second step following FIG. 2. (A) is an enlarged view of the IVa part of FIG. 3, (b) is an IVb arrow line view of FIG. It is a schematic diagram explaining a 3rd step. (A) is an enlarged view of the VIa part of FIG. 5, (b) is a VIb arrow line view of FIG. 5, (c) is a figure corresponding to FIG.6 (b), Comprising: Other embodiment FIG. FIG. 6 is a schematic diagram illustrating a third step following FIG. 5. It is a VIII arrow line view of FIG. It is a schematic diagram which shows one Embodiment of the connection form between reinforcement rings in case a reinforcement ring continues in the axial direction of an existing lining.

  Embodiments of a reinforcing method and a reinforcing device for an existing lining according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view of an embodiment of an arc block. FIGS. 2, 3, 5 and 7 are flow charts of the reinforcing method of the present invention in order, FIG. 2 is a first step, and FIG. The first step, the second step, and FIGS. 5 and 7 are schematic diagrams for explaining the third step in order, and each is a view of the existing lining as viewed in a vertical cross section orthogonal to the axial direction.

  The existing lining F shown in FIG. 2 is a shield tunnel constructed by a shield method in the ground E in an urban area. A plurality of arc-shaped reinforced concrete segments S are surrounded by an erector in a shield machine not shown. It is assembled in the direction (C direction) to form a ring shape having a circular cross section, and this is assembled in the tunnel axis direction to form a tunnel having a predetermined length. The cross-sectional shape of the existing tunnel is not limited to the circular shape (new circular shape) shown in the figure, and may be an elliptical shape or a cross-sectional shape having different curvatures in the upper and lower halves. In addition, existing tunnels are not limited to shield tunnels, but include existing tunnels that require reinforcement, such as propulsion tunnels using the propulsion method and excavation tunnels using the excavation method.

  This existing lining F has insufficient structural strength against the changed working earth pressure or earth water pressure due to the construction of a separate tunnel in the surrounding ground E or the fluctuation of the groundwater level, or it is excessive due to these fluctuating loads. There are problems such as deformation, leakage due to excessive deformation and cracks due to aging of components, etc.For this reason, a new reinforcing ring is built inside the existing lining and Reinforcing.

  First, an arc-shaped block 1 for forming a reinforcing ring as shown in FIG. 1 is prepared. This arc-shaped block 1 has a circular arc shape of a part of a circle forming the inner surface of the existing lining F to be reinforced, and is made of a concrete or steel segment having a predetermined width and a predetermined thickness.

  A buffer layer 2 of rubber material is formed on the outer surface 1b on the existing lining side of the arc-shaped block 1, and both when the segment S constituting the existing lining F and the arc-shaped block 1 are in direct contact with each other during construction or operation. Is to prevent damage. For example, the existing lining F is excessively deformed, and the case where the arc-shaped block 1 cannot be installed as designed when the arc-shaped block 1 is installed in this deformed portion, or the surface roughness of the segment S is increased due to aging. In such a case, at least the outer surface of the arc-shaped block 1 may be damaged when it comes into contact with the segment S. Therefore, the buffer layer 2 is provided to reduce this possibility of damage.

  Further, of the arc-shaped block 1, the circumferential end surface 1 a when the block is installed on the inner surface of the existing lining F is inward at an angle θ with respect to the normal line of the arc (from the outer surface 1 b toward the inner side). And a tapered surface formed in a tapered shape.

  Prepare the arcuate block 1 of the radix required to construct one reinforcing ring inside the existing lining F. In addition, when constructing a reinforcing ring connected in the axial direction of the existing lining F over a predetermined extension, an arc-shaped block 1 having a radix calculated by the radix required for forming one reinforcing ring × the number of reinforcing rings is prepared. .

  First, a predetermined interval G is set in the circumferential direction of the existing lining F (direction C in FIG. 2) using a temporary receiving carriage or the like (not shown) that is self-running in the existing lining F. A plurality of arc-shaped blocks 1,... Are arranged and temporarily received. Further, as shown in FIG. 3, jacks 3 such as hydraulic jacks and giraffe jacks are arranged and temporarily received in each gap G ( First step). In addition, the jack 3 is arrange | positioned in the center position of the end surface 1a of the arc-shaped block 1, as shown in FIG. 4b.

  Here, between the end surface 1a of the arc-shaped block 1 and the jack 3 so that the jack 3 can push the end surface 1a of the arc-shaped block 1 in the arc direction of the arc-shaped block 1, as shown in FIG. A triangular angle adjusting insertion tool 4 having an angle θ is disposed to form a flat surface (a surface orthogonal to the direction along the arc direction of the arc-shaped block 1). By pushing the flat surface of the angle adjusting insertion tool 4 with the jack, the pushing force of the jack can be effectively applied to the arc-shaped block 1.

  After the plurality of arc-shaped blocks 1,... And the jacks 3,... Are assembled and provisionally received in the circumferential direction of the existing lining F, the jacks 3 are then synchronously controlled to be similar to the corresponding left and right arc-shaped blocks 1, 1. An axial force N ′ is applied.

  When a certain axial force N ′ is introduced into each arc-shaped block 1, the plurality of arc-shaped blocks 1,... And jacks 3,. 10 ′) can be formed, and at this stage, the provisional reception by the elector device or the like is released.

  By gradually increasing the amount of overhanging of each jack 3,..., The gap G between the arc-shaped blocks 1 and 1 increases, and the intermediate reinforcing ring 10 'expands in the process in which each gap G increases synchronously. The diameter will continue.

  As the diameter of the intermediate reinforcing ring 10 ′ is increased, the radial force due to the axial force N ′ of the intermediate reinforcing ring 10 ′ (equally distributed load q ′ = N ′ / r ′ (r ′ is the intermediate force at that time) The radius of the reinforcing ring 10 ′) acts on the existing lining F, and the existing lining F is pushed out to the ground E side by this force. Therefore, when a part of the existing lining F is deformed inward, this deformation can be pushed out to the natural ground E side, and the deformation can be mitigated. It is possible to reduce the stress and recover the proof stress of the existing lining F.

  The equally distributed load q ′ can be applied to the existing lining F from the intermediate reinforcing ring 10 ′, and can further be applied in the direction of pushing out the natural ground E from the existing lining F (the direction of pushing back) through the existing lining F. The earth pressure and earth water pressure acting on the existing lining F from the natural ground E are offset by the pushing force applied to the existing lining F from the intermediate reinforcing ring 10 '.

  The extension control of each jack 3 is stopped at the stage where the intermediate reinforcing ring 10 'is expanded to a predetermined diameter (second step).

  Next, with respect to the gap G having the width at the end of overhanging with the jack 3, as shown in FIG. 5, the gap holding member 5 holding this gap G is inserted into the gap G. The reaction force is exchanged. More specifically, as shown in FIG. 6a, the formed gap G has a trapezoidal shape formed by the tapered surfaces 1a and 1a on both sides in the cross-sectional view, and holds the gap inserted therein. Similarly, the material 5 having a trapezoidal shape is used, which forms a wedge (first wedge), and can firmly connect the arc-shaped blocks 1 and 1 on both sides having an axial force (compression force). As shown in FIG. 6b, the spacing members 5 are disposed at two locations on both sides of the jack 3 at the center position of the end face 1a.

  Here, in order to increase the bonding strength between the spacing member 5 and the arc-shaped block 1, both the arc-shaped block 1 and the spacing member 5 may be connected by a bolt B as shown in FIG.

  When the jack reaction force is changed by each spacing member 5, the protruding amount of the jack 3 is reduced, and the jack 3 is removed from the spacing G, whereby a plurality of arc-shaped blocks 1,. The reinforcing ring 10 is formed of the spacing members 5.

  As shown in the figure, the central position of the end surface 1a of the arc-shaped block 1 is pushed out by the jack 3, and the spacing members 5 and 5 are arranged at two positions on both sides of the jack (the same offset position on the left and right from the central position). Therefore, when the jack 3 is pushed out, an unbalanced load does not act on the arc-shaped block 1, and after the jack reaction force is transferred to the spacing member 5, an unbalanced load does not act on the arc-shaped block 1.

  As shown in FIGS. 7 and 8, grout (mortar, cement paste, etc.) is filled and cured in the gap defined by the end faces 1a, 1a of the opposing arc-shaped blocks 1, 1 and the two spacing members 5, 5. By performing the stuffing process (stuffing portion 6), the reinforcing ring 10 that is strong in the circumferential direction is formed (third step).

  Thus, according to the reinforcing method of the existing lining of the present invention, the reinforcing ring 10 capable of generating an axial force in the circumferential direction on the inner surface of the existing lining F having a circular cross section or the like is constructed. An axial force is generated to increase the diameter of the reinforcing ring 10, and in the process of expanding the diameter of the reinforcing ring 10, a force to push the existing covering F to the ground E side is applied. The existing lining can be effectively reinforced while reducing the internal stress by forcibly relieving the deformation of the existing lining F and reducing the internal stress.

  FIG. 9 is a view showing an embodiment of a connection form between adjacent reinforcing rings 10 when the above-described reinforcing method is expanded in the axial direction (longitudinal direction) of an existing lining.

  In the illustrated embodiment, for example, a plurality of reinforcing rings 10,... Are continuously constructed in the axial direction (J direction) of the existing lining F to reinforce an arbitrary extension section, and in the circumferential direction (C direction). The space G between the arc-shaped blocks 1 and 1 constituting the reinforcing ring 10 has a trapezoidal shape, and the trapezoidal first wedge (spacing retaining member 5) is disposed here, as well as in the axial direction. End surfaces 1c and 1c of the corresponding arc-shaped blocks 1 and 1 between the reinforcing rings 10 and 10 to be formed are tapered, and a trapezoidal space is formed between the reinforcing rings 10 and 10. Then, the second wedges 7 and 7 having the same shape as the trapezoidal space are arranged, and the interstitial portion 8 is constructed between the second wedges 7 and 7 so that the reinforcing rings 10 and 10 are firmly fixed in the axial direction. It is what connects.

  A plurality of arc-shaped blocks 1,... Arranged in the circumferential direction of the inner surface of the existing lining F shown in FIGS. 1 and 2, and jacks shown in FIG. 3. A jack 3 is provided, which extends a plurality of jacks 3,... To widen a gap G between the arc-shaped blocks 1, 1, and applies a circumferential axial force N to the arc-shaped blocks. 5 which is disposed in the gap G and holds the gap G, and the gap holding material 5 replaces the jack reaction force when the jack 3 is removed from the gap G. At least a plurality of arc-shaped blocks 1,... And a plurality of spacing members 5,.

  This reinforcing device preferably includes a buffer layer 2 made of a rubber material on the outer surface 1b on the existing lining side of the arc-shaped block 1 which is a constituent member thereof.

  As another embodiment of the reinforcing device, as shown in FIG. 9, the reinforcing ring 10 is arranged with an interval in the axial direction (J direction) of the existing lining F, and adjacent reinforcing members are provided. The axial end faces 1c and 1c of the two arc-shaped blocks 1 and 1 opposed to the rings 10 and 10 are also tapered surfaces, whereby the axial interval has a trapezoidal shape in plan view. An embodiment in which the second wedge 7 having a trapezoidal shape in plan view is disposed within the interval of.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Arc-shaped block, 1a ... End surface of the circumferential direction, 1b ... Outer surface of the existing lining side, 2 ... Buffer layer, 3 ... Jack, 4 ... Angle adjustment insertion tool, 5 ... Space | interval holding material (1st wedge), 6 ... Spacing part, 7 ... Spacing retaining material (second wedge), 8 ... Spacing part, 10 ... Reinforcing ring, G ... Spacing, S ... Segment, F ... Existing lining, E ... Ground (ground) , C ... circumferential direction, J ... axial direction of existing lining

Claims (12)

A first step of arranging a plurality of arc-shaped blocks at intervals in the circumferential direction of the inner surface of the existing lining having a circular or substantially circular cross section in the underground tunnel, and arranging a jack in the interval;
A second step of applying a circumferential axial force to each arc-shaped block while extending a plurality of jacks to widen the interval between the arc-shaped blocks;
A plurality of spacing members that are arranged in the circumferential direction are arranged at least in the circumferential direction by disposing a spacing member that retains the spread spacing in the plurality of spacings, removing the jack from the spacing and replacing the jack reaction force with the spacing member. A method for reinforcing an existing lining, comprising a third step of forming a reinforcing ring comprising an arc-shaped block and a plurality of spacing members. Among the arc-shaped blocks, an end surface facing an adjacent arc-shaped block has a tapered surface inclined from the existing tunnel side to the inside of the tunnel, and the interval has a trapezoidal shape in a sectional view extending to the inside of the tunnel by two tapered surfaces on both sides thereof. Presents
The method of reinforcing an existing lining according to claim 1, wherein the spacing member is a first wedge having a trapezoidal cross-sectional shape that is the same as the spacing.   The reinforcing method for an existing lining according to claim 2, wherein an angle adjusting insertion tool is disposed between the tapered surface of the arc-shaped block and the jack, and the jack presses a flat surface of the angle adjusting insertion tool. . In the first step, the jack is arranged at a substantially central position of the end face of the arc-shaped block,
The reinforcing method of the existing lining according to any one of claims 1 to 3, wherein, in the third step, the spacing member is disposed on both sides of the jack on the end surface.   The reinforcing method of the existing lining according to claim 4, wherein in the third step, after the jack is removed, a stuffing process is performed between the two spacing members.   The method for reinforcing an existing lining according to any one of claims 1 to 5, wherein a buffer layer is provided on an outer surface of the arc-shaped block that comes into contact with the existing lining.   The reinforcing ring is disposed at an interval in the axial direction of the existing lining, and the axial end surfaces of the two arc-shaped blocks facing each other of the adjacent reinforcing rings are also tapered surfaces. The interval in the axial direction has a trapezoidal shape in plan view, and the second wedge having a trapezoidal shape in plan view is disposed within the interval in the axial direction. Reinforcement method.   8. The existing one according to claim 7, wherein two second wedges are disposed on tapered surfaces of arcuate blocks opposed to each other with an interval in the axial direction, and a filling process is performed between the two second wedges. Reinforcement method of lining. A plurality of arc-shaped blocks arranged at intervals in the circumferential direction of the inner surface of the existing lining having a circular or substantially circular cross section in the underground tunnel;
Jacks that are arranged in each of the intervals, and a jack that applies a circumferential axial force to each arc-shaped block while extending a plurality of jacks to widen the interval between the arc-shaped blocks, and
An interval holding material that is arranged in the spread interval and holds the interval;
The existing cover that replaces the reaction force of the jack when the jack is removed from the gap, and forms a reinforcing ring composed of a plurality of arc-shaped blocks arranged at least in the circumferential direction and a plurality of gap retainers. Work reinforcement device. Among the arc-shaped blocks, an end surface facing an adjacent arc-shaped block has a tapered surface inclined from the existing tunnel side to the inside of the tunnel, and the interval has a trapezoidal shape in a sectional view extending to the inside of the tunnel by two tapered surfaces on both sides thereof. Presents
The reinforcing device for an existing lining according to claim 9, wherein the spacing member is a first wedge having a trapezoidal cross-sectional shape that is the same as the spacing.   The reinforcing device for an existing lining according to claim 9 or 10, wherein a buffer layer is provided on an outer surface of the arc-shaped block that comes into contact with the existing lining.   The reinforcing ring is disposed at an interval in the axial direction of the existing lining, and the axial end surfaces of the two arc-shaped blocks facing each other of the adjacent reinforcing rings are also tapered surfaces. The existing cover according to any one of claims 9 to 12, wherein the interval in the axial direction has a trapezoidal shape in plan view, and a second wedge having a trapezoidal shape in plan view is arranged in the interval in the axial direction. Work reinforcement device.

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