Recoverable shield tunneling machine and tunnel construction method using recoverable shield tunneling machine

Abstract

To provide a recoverable shield tunneling machine and a tunnel construction method using the same, which can prevent a construction period from becoming longer and reduce construction costs when connecting a plurality of separate tunnels at midpoints of a tunnel while reusing the shield tunneling machine.SOLUTION: A recoverable shield tunneling machine 40 reuses a portion of a tunnel 30 extending from a launch section 10 to an arrival section 20 after constructing the tunnel, and comprises a recovery unit 50 and an outer shell 60. The recovery unit 50 comprises an inner shell 51, a cutter head 52, a drive unit 55, and a shield jack 57. The outer shell 60 surrounds the inner shell 51 and is detachably attached to the inner shell 51. A tunnel box group 70A consisting of a plurality of tunnel boxes 70 is connected to the rear of the outer shell 60 so as to be propelled. A thrust transmission member 80 that takes reaction force from the launch section 10 is disposed inside the tunnel box group 70A and extends to the shield jack 57.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a retrievable shield machine and a tunnel construction method using a retrievable shield machine. [Background technology]

[0002] In recent years, when constructing pipes such as utility conduits, water supply and sewerage systems, and stormwater collection pipes in underground spaces in urban areas, it has become common to use the deep, long-distance shield tunneling method to prevent disruption to ground traffic and minimize the impact on residents living along the roads. Therefore, in the case of a shield tunnel (main pipe) with a long construction length, in order to make it possible to connect a branch pipe from the ground to the main pipe at an intermediate section of the main pipe during construction, an intermediate shaft is sometimes constructed near the middle of the main pipe, and a branch pipe leading from the intermediate shaft to the main pipe is constructed to connect the two.In many cases, multiple intermediate shafts are constructed on the side of a long main pipe, and construction to connect the branch pipes from each intermediate shaft to the main pipe is carried out multiple times. Furthermore, when connecting the main pipe to the branch pipe from the intermediate shaft at great depths, construction generally takes place under high water pressure, so sealed shield or jacking methods are generally used to prevent the collapse of the ground or the eruption of groundwater. The construction method involves assembling the shield tunneling machine and pusher below the intermediate shaft, commencing excavation from below the intermediate shaft, bringing the shield tunneling machine to the main pipe and constructing the primary lining, then removing the various pieces of equipment inside the shield tunneling machine (cutter head, drive unit that rotates the cutter head, shield jack, erector device, etc.) from inside the main pipe and from the intermediate shaft side, and constructing the branch pipe by constructing the secondary lining inside the primary lining, and completing the connection construction between the main pipe and the constructed portion of the intermediate shaft via the branch pipe.

[0003] According to the above construction method, when there are multiple connection constructions using multiple branch pipes, the increase in costs due to the need to manufacture multiple shield tunneling machines and thrusters becomes a major issue. Furthermore, if the method of repurposing removed equipment is adopted, delays in construction time will become a new issue, considering the time it takes to remove the equipment and the time it takes to assemble it into the main body at the factory and reuse it, and then manufacture new shield tunneling machines, etc. The length of the branch pipes connecting the main pipe and the construction section of the intermediate shaft is generally at most 20m, so considering that the time required for excavation by a shield tunneling machine, etc. is not that long, the time required for assembling the shield tunneling machine, preparing for excavation, and dismantling it after reaching the main pipe, etc., is longer than the time required for excavation by the shield tunneling machine, etc., and the proportion of the overall construction period required for dismantling and reconstructing the shield tunneling machine, etc., is large.

[0004] In view of the above, when constructing multiple tunnels connecting starting and ending sections using a reusable shield machine, it is desirable to have a recoverable shield machine that can prevent construction time from being extended and reduce construction costs, as well as a tunnel construction method using the same.

[0005] Patent Document 1 proposes a shield tunneling machine with a retrievable cutter drive unit. This shield tunneling machine is equipped with a rotary cutter, a center shaft, a partition wall, and a drive unit that transmits driving force from a drive source to the center shaft. The center shaft includes a cutter-side center shaft that is equipped with a rotary cutter and rotatably mounted on the partition wall, and a drive-side center shaft that is rotatably mounted on the drive unit, and the cutter-side center shaft and the drive-side center shaft are detachably fitted and connected. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-16969 Summary of the Invention [Problem to be solved by the invention]

[0007] The shield tunneling machine described in Patent Document 1 is said to be able to recover the center shaft without the need for an arrival shaft or ground improvement work. However, this is limited to recovering the center shaft and does not disclose means for recovering the various components that make up the shield tunneling machine, such as the cutter head, steel shell, and shield jack. Furthermore, when reusing shield tunneling machines that have been used in conventional shield construction methods, including the shield tunneling machine described in Patent Document 1, multiple shield jacks are arranged in a position directly opposite the segment joint surfaces of the segment ring so that they can excavate by applying a reaction force to the segment ring formed by assembling multiple segments behind the shield tunneling machine.Since the segment ring and each shield jack interfere with each other, it is necessary to dismantle each shield jack, and at the same time, when dismantling each shield jack, it is necessary to dismantle each shield jack one by one, which takes a lot of time.

[0008] The present invention aims to provide a reusable shield tunneling machine that can prevent construction time from being extended and reduce construction costs when constructing multiple tunnels connecting a starting section and a reaching section using the reusable shield tunneling machine, and a tunnel construction method using the same. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the retrievable shield tunneling machine according to the present invention comprises: A recoverable shield tunneling machine that starts from a starting section, constructs a tunnel underground extending to a reaching section, and then can recover a portion of the tunnel for reuse, a collection unit and an outer shell; The recovery unit comprises: The excavation tunnel is provided with an inner shell, a cutter head located in front of the inner shell in the excavation direction, and a drive unit and a shield jack that drive the cutter head located inside the inner shell, the outer shell surrounds the inner shell and is detachably attached to the inner shell, A group of tunnel boxes consisting of a plurality of tunnel boxes is connected to the rear of the outer shell in the excavation direction and is advanced. a thrust transmission member that receives a reaction force from the launch section is disposed inside the tunnel box group and extends to the shield jack, The shield jack reaches the reach section by excavating using the reaction force of the thrust transmission member, and after a tunnel consisting of the outer shell and the group of tunnel boxes is constructed, the inner shell is detached from the outer shell, making the recovery unit freely recoverable.

[0010] According to this aspect, the recoverable shield tunneling machine has a recovery unit and an outer shell, and the recovery unit includes an inner shell, a cutter head located in front of the inner shell in the excavation direction, a drive unit that drives the cutter head inside the inner shell, and a shield jack.As a result, many of the components of the shield tunneling machine can be recovered as a single unit and reused.When manufacturing a new shield tunneling machine (recycling a shield tunneling machine), it is sufficient to attach a new outer shell to the outer periphery of the recovered recovery unit, which shortens the time required to manufacture a new shield tunneling machine and prevents the overall construction period from becoming longer when reusing a shield tunneling machine to construct multiple tunnels, thereby reducing construction costs.

[0011] Furthermore, the shield tunneling machine of this type is not a shield tunneling machine applied to conventional general shield construction methods in which a shield jack excavates by receiving a reaction force from the segment ring behind it, but rather excavates by receiving a reaction force from the starting part via a thrust transmission member arranged inside a tunnel box group consisting of multiple tunnel boxes, and since each shield jack and the tunnel box group are not in a position where they will interfere with each other, not only is the process of dismantling each shield jack one by one unnecessary, but dismantling the shield jack itself is also unnecessary.

[0012] The outer shell that constitutes the shield tunneling machine forms a tunnel together with the group of tunnel boxes connected to the rear of it, and after the tunnel is constructed, the inner shell of the recovery unit is removed from the outer shell, making it easy to recover the recovery unit.

[0013] In this type of shield tunneling machine, a segment ring is formed by assembling steel segments that serve as thrust transmission members at the rear of its main body (inner shell).However, since there is no need for the outer periphery to be strong enough to withstand earth pressure or to be waterproof, the number of segments can be increased and the weight per piece reduced so that the assembly can be done by hand, or an erector device can be provided if necessary.

[0014] Furthermore, a group of tunnel boxes is formed by sequentially connecting the tunnel boxes to the rear of the outer shell at the starting section, and as the shield tunneling machine excavates, the pieces that make up the thrust transmission member are sequentially added, lengthening the extension of the thrust transmission member between the reaction force base and the shield jack, and the shield tunneling machine excavates while driving the shield jack to receive the reaction force at the starting section via the thrust transmission member, thereby extending the group of tunnel boxes.Therefore, the construction method using a shield tunneling machine of this type can be said to be a tunnel construction method that combines the features of both the jacking method and the shield method.

[0015] The recovery unit is removed from the shell and recovered, for example, at the starting section, whereby the tunnel consisting of the shell and the group of tunnel boxes forms a primary lining connecting the starting section and the arrival section. A secondary lining, for example made of reinforced concrete, may be constructed inside the primary lining as necessary.

[0016] Here, the starting section may be a vertical shaft, such as the intermediate shaft described above, or a tunnel such as a shield tunnel or a jacking tunnel, or even aboveground space. Meanwhile, the reaching section may be a tunnel, such as the long shield tunnel described above, or a vertical shaft or aboveground space. That is, the retrievable shield machine of this embodiment may be used not only for constructing a branch pipe connecting an intermediate shaft and a long shield tunnel, but also for various types of construction work connecting starting sections and reaching sections, such as connecting tunnels with branch pipes, connecting underground structures other than tunnels with branch pipes, connecting the lower part of a shaft or a tunnel with the ground with branch pipes, and connecting multiple aboveground spaces in different locations with tunnels (branch pipes) constructed underground (construction connecting closed railroad crossings with an underpass).

[0017] In another aspect of the retrievable shield tunneling machine according to the present invention, the thrust transmission member is formed of a steel segment without a skin plate; The steel segments are extended and lengthened as the shield machine excavates.

[0018] According to this aspect, the thrust transmission member is formed from steel segments that do not have skin plates, and the steel segments are extended to increase in length as the shield tunneling machine excavates.This means that the length of the thrust transmission member can be freely adjusted to a length that corresponds to the excavation speed of the shield tunneling machine by using segments that are high-strength and have as simple a configuration as possible.

[0019] Here, when the steel segments that form the thrust transmission member are transported inside the shield tunneling machine and new thrust transmission members are assembled and installed to extend the overall length of the thrust transmission member, as with conventional shield tunneling, only the shield jack in the assembly space for one piece of the divided steel segment is pulled, and the remaining shield jacks can receive reaction force from the thrust transmission member, eliminating the risk of backing due to water pressure or soil pressure acting on the cutter head, etc. On the other hand, if a retrievable thruster is used, the thruster jack in the intermediate shaft must be retracted to ensure space for assembling the steel shell. Therefore, the thruster cannot receive reaction force from the steel shell when assembling the steel shell, raising concerns about backing due to water pressure or soil pressure acting on the cutter head, etc. Therefore, each time the steel shell is assembled, it is necessary to temporarily fix part of the tunnel box group connected to the rear of the outer shell and the starting entrance, etc., by welding or other means, to prevent backing of the thruster, which delays the process.

[0020] In another aspect of the retrievable shield tunneling machine according to the present invention, The cutter head has an inner part and an outer peripheral part around the inner part, and the inner part and the outer peripheral part are detachable, an outer peripheral surface of the outer peripheral portion is flush with the outer surface of the outer shell or protrudes laterally toward the natural ground beyond the outer surface of the outer shell when the shield machine excavates; The recovery unit does not include the outer periphery.

[0021] According to this aspect, the cutter head comprises an inner part and an outer peripheral part surrounding it that is flush with the outer surface of the outer shell or that protrudes laterally toward the ground beyond the outer surface, and both are detachable.Since the recovery unit does not include the outer peripheral part, the cutter head can be used to excavate up to the outer surface of the outer shell, while recovering the recovery unit through the outer shell and the inside of the tunnel box group.

[0022] For example, after a shield machine reaches a target section, the outer periphery of the cutter head can be removed to form a recoverable unit, which can then be reused. A new outer shell can be attached to the recovered unit, and a new outer periphery can be attached to the inner part to regenerate the cutter head, producing a new recoverable shield machine.

[0023] In another aspect of the retrievable shield tunneling machine according to the present invention, the cutter head has an inner portion and an outer periphery surrounding the inner portion; The outer peripheral portion is extendable and contractible in a radial direction from the inside of the inner portion, The outer peripheral portion extends from the inner portion when the shield tunneling machine is excavating, so that its outer surface is flush with the outer surface of the outer shell or extends toward the ground to the side of the outer surface of the outer shell, and is housed in the inner portion when the recovery unit is recovered.

[0024] According to this aspect, the outer peripheral part that constitutes the cutter head is freely expandable and contractible in the radial direction from inside the inner part, and when the shield tunneling machine excavates, the outer peripheral part extends from the inner part, making its outer surface flush with the outer surface of the outer shell or extending further towards the ground to the side than the outer surface, and when the recovery unit is recovered, it is stored in the inner part, so that while the cutter head excavates up to the outer surface of the outer shell, the recovery unit can be recovered through the inside of the outer shell and the tunnel box group without removing the outer peripheral part from the cutter head.

[0025] In another aspect of the retrievable shield tunneling machine according to the present invention, The inner shell is provided with a first filling hole, the outer shell is provided with a second filling hole, and the tunnel box is provided with a third filling hole, The method is characterized in that during excavation, a lubricant is injected around the outer shell and / or around the tunnel box through the first filling hole and the second filling hole, and / or through the third filling hole, and backfill material is filled in after excavation is completed.

[0026] According to this aspect, after excavation is completed, backfill material is filled around the outer shell and the tunnel box through filling holes provided in the inner shell, outer shell, and tunnel box, thereby blocking the water supply formed between the outer shell or tunnel box and the surrounding ground with the backfill material, and waterproofing the tunnel entrance formed when the shield tunneling machine reaches the reach point.

[0027] Furthermore, one aspect of the tunnel construction method using the retrievable shield machine according to the present invention is to A tunnel construction method using a retrievable shield machine, in which a part of the shield machine is retrievable, is started from a starting point, a tunnel is constructed underground extending to a reaching point, and then a part of the shield machine is retrievable for reuse, the recoverable shield machine includes a recovery unit and a hull; The recovery unit comprises: The excavation tunnel is provided with an inner shell, a cutter head located in front of the inner shell in the excavation direction, and a drive unit and a shield jack that drive the cutter head located inside the inner shell, the outer shell surrounds the inner shell and is detachably attached to the inner shell, The shield tunneling machine is launched from the launch section, tunnel boxes are connected in sequence behind the outer shell in the excavation direction, and thrust transmission members that receive reaction force from the launch section are arranged inside the tunnel boxes and connected in sequence, the shield jack receives reaction force from the thrust transmission members and excavates, and the shield tunneling machine reaches the reach section, thereby constructing a tunnel formed by a group of tunnel boxes consisting of a plurality of tunnel boxes and the outer shell, and then the inner shell is removed from the outer shell and the recovery unit is recovered.

[0028] According to this aspect, a recoverable shield tunneling machine having a recovery unit and an outer shell is used, and the recovery unit includes an inner shell, a cutter head located in front of the inner shell in the excavation direction, a drive unit that drives the cutter head inside the inner shell, and a shield jack.As a result, many of the components of the shield tunneling machine can be recovered and reused as a single unit, and when manufacturing a new shield tunneling machine, it is sufficient to attach a new outer shell to the outer periphery of the recovered recovery unit.This shortens the time required to manufacture a new shield tunneling machine, prevents the overall construction period from becoming longer when reusing a shield tunneling machine to construct multiple tunnels, and reduces construction costs.

[0029] Another aspect of the tunnel construction method using a retrievable shield machine according to the present invention is to A new outer shell is attached to the recovered unit to form a new shield tunneling machine, and a separate tunnel is constructed using the new shield tunneling machine.

[0030] According to this aspect, a new outer shell is attached to the recovered recovery unit to form a new shield tunneling machine, and the new shield tunneling machine is used to construct a separate tunnel, thereby shortening the time required to manufacture a new shield tunneling machine, preventing the overall construction period from becoming longer when reusing a shield tunneling machine to construct multiple tunnels, and reducing construction costs.

[0031] Another aspect of the tunnel construction method using a retrievable shield machine according to the present invention is to It is a shield tunnel with an intermediate shaft at the starting point and a main tunnel at the end point. Assembling the tunnel box in the intermediate shaft; The thrust transmission member receives a reaction force from a reaction force frame located inside the intermediate shaft, When recovering the recovery unit, rails are laid below the constructed tunnel, and the recovery unit is transported along the rails to the intermediate shaft for recovery.

[0032] According to this aspect, in construction in which branch pipes are constructed between a main pipe consisting of a long shield tunnel and multiple intermediate shafts to connect each of the intermediate shafts to the main pipe, after constructing the tunnel that constitutes one branch pipe, when retrieving the recovery unit, rails can be laid below the constructed branch pipe and the recovery unit can be transported along the rails to the intermediate shaft for retrieval, thereby achieving efficient retrieval of the recovery unit. For example, by loading the recovery unit onto a cart that runs on the rails and running the cart along the rails to the intermediate shafts, smooth retrieval of the recovery unit along the rails can be achieved. [Effects of the Invention]

[0033] According to the recyclable shield tunneling machine of the present invention and the tunnel construction method using the recyclable shield tunneling machine, when constructing multiple tunnels connecting a starting section and a reaching section using a reusable shield tunneling machine, it is possible to prevent the construction period from becoming too long and reduce construction costs. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a process diagram of an example of a tunnel construction method using a retrievable shield machine according to an embodiment, and is also a side view illustrating the state in which the retrievable shield machine according to an embodiment is preparing to depart inside an intermediate shaft. [Figure 2] 1 , and is a side view illustrating the state in which the recoverable shield machine according to the embodiment starts excavating from an intermediate shaft. [Figure 3] Following Figure 2, this is a process diagram of an example of a tunnel construction method using a retrievable shield machine according to an embodiment, and is a side view illustrating the state in which the retrievable shield machine according to an embodiment has reached the main pipe. [Figure 4]Following Figure 3, this is a process diagram of an example of a tunnel construction method using a recoverable shield machine according to an embodiment, and is also a side view illustrating the state in which the outer shell and inner shell that make up the recoverable shield machine according to an embodiment have been removed, and the outer periphery has been removed from the inner part of the cutter head. [Figure 5] 5 is a process diagram of an example of a tunnel construction method using a retractable shield machine according to an embodiment, following FIG. 4, and is a side view illustrating the state in which the recovery unit is being retracted into the intermediate shaft. [Figure 6] 5, and is a process diagram of an example of a tunnel construction method using a retrievable shield machine according to an embodiment, and is a side view illustrating the state before the recovery unit is recovered into the intermediate shaft and hoisted to the ground. DETAILED DESCRIPTION OF THE INVENTION

[0035] A tunnel construction method using a retractable shield machine and a retractable shield machine according to an embodiment will be described below with reference to the accompanying drawings. Note that in this specification and drawings, substantially identical components will be designated by the same reference numerals, and redundant explanations may be omitted.

[0036] [Recoverable shield machine according to the embodiment and tunnel construction method using the same] An example of a retrievable shield machine according to an embodiment and a tunnel construction method using the same will be described with reference to FIGS. 1 to 6. FIG. Here, Figs. 1 to 6 are, in order, process diagrams of an example of a tunnel construction method using a retrievable shield machine according to an embodiment. Fig. 1 is a side view illustrating a state in which a retrievable shield machine according to an embodiment is preparing to depart from the intermediate shaft, Fig. 2 is a side view illustrating a state in which a retrievable shield machine according to an embodiment has departed from the intermediate shaft and is excavating, and Fig. 3 is a side view illustrating a state in which a retrievable shield machine according to an embodiment has reached a main pipe. Fig. 4 is a side view illustrating a state in which the outer and inner shells constituting a retrievable shield machine according to an embodiment have been removed and the outer periphery has been removed from the inner part of the cutter head, Fig. 5 is a side view illustrating a state in which a recovery unit has been retracted into the intermediate shaft, and Fig. 6 is a side view illustrating a state in which the recovery unit has been recovered into the intermediate shaft and is about to be hoisted above ground.

[0037] In the following description, the reach section 20 is a long, deep shield tunnel (main pipe) currently under construction, and the start section 10 is an intermediate shaft located at most 20 m to the side of the midpoint of the shield tunnel 20. The shield machine 40 excavates from the intermediate shaft 10 to reach the midpoint of the shield tunnel 20, and the method for constructing a tunnel 30 (branch pipe) connecting the shield tunnel 20 and the intermediate shaft 10 is described. However, there are various other configurations of the reach section and the start section besides the illustrated example. Specifically, the start section may be a tunnel such as a shield tunnel or a jacking tunnel, or even an aboveground space, and the reach section may be a vertical shaft or aboveground space. In other words, the retrievable shield machine and tunnel construction method according to the embodiment may be used for various types of construction work connecting start sections and reach sections, such as construction work connecting tunnels with branch pipes, construction work connecting the lower part of a vertical shaft or a tunnel with the ground with branch pipes, and construction work connecting multiple aboveground spaces in different locations with tunnels (branch pipes) constructed underground.

[0038] The shield tunnel 20, which is the main pipe shown in Figure 1, is formed by joining multiple segment rings 21 together along its length via segment joints, and is a tunnel that serves as a culvert for, for example, utility sewerage, water supply and sewerage, rainwater storage pipes, etc.

[0039] In order to allow free access to the ground at midpoints of a long shield tunnel 20, multiple intermediate shafts 10 are constructed near the sides of the tunnel, within a range of about 20 m or less, and each intermediate shaft 10 is connected to the shield tunnel 20 by, for example, a tunnel 30 (branch pipe) having a straight line shape. The construction of the tunnel 30 (branch pipe) connecting this intermediate shaft 10 to the shield tunnel 20 is carried out by a retrievable shield machine 40 starting from the intermediate shaft 10 and reaching the shield tunnel 20, and a portion of the retrievable shield machine 40 is recovered and reused, and new retrievable shield machine 40 is regenerated while multiple tunnels 30 connecting the multiple intermediate shafts 10 to the shield tunnel 20 are constructed one after another.

[0040] Normally, such an intermediate shaft 10 and a long shield tunnel 20 are connected by multiple branch pipes 30, requiring multiple shield machines to construct the branch pipes 30. However, when constructing multiple short tunnels of around 20m, it is uneconomical to prepare a separate shield machine for each tunnel, as this would unnecessarily increase construction costs. Therefore, a recyclable shield machine 40 is used to construct the multiple branch pipes 30 connecting the shield tunnel 20 and intermediate shaft 10 one after the other, reusing a single recyclable shield machine 40.

[0041] In this case, if a recyclable shield tunneling machine is used, but it takes a long time to recover and regenerate (remanufacture) its components, the construction period will be longer and construction costs will increase, and the original effect of using a recyclable shield tunneling machine, which is to reduce construction costs, will not be fully realized.

[0042] Therefore, the illustrated example of a retrievable shield machine 40 described below and the tunnel construction method using it make it possible to prevent the construction period from becoming too long and reduce construction costs.

[0043] As shown in Figure 1, intermediate shaft 10 (an example of a launch section) has a front wall 11 located forward in the excavation direction, a bottom slab 13, and a rear wall 14, and front wall 11 is provided with a cuttable cutting wall 12 so that a recoverable shield tunneling machine 40 can launch from it. For example, cutting wall 12 may be a wall made of FFU (FFU: Fiber reinforced Foamed Urethane, a long glass fiber reinforced plastic foam), which is the same material as the FFU segments described below.

[0044] Here, the intermediate shaft 10 has an outer shape such as a circular cross-sectional shape perpendicular to its longitudinal direction at the top and bottom (hence a cylindrical shape with a bottom plate) or a rectangular cross-sectional shape (a square cylindrical shape with a bottom plate).

[0045] The intermediate shaft 10 may be a shaft made of reinforced concrete or a steel shaft. Around the cutting wall 12 (only the top and bottom are shown in FIG. 1 ), an entrance 15 is provided to guide the direction in which the retrievable shield machine 40 departs after cutting the cutting wall 12.

[0046] On the other hand, cuttable segments 23 are applied to the segments of the shield tunnel 20 in the reachable area that the shield machine 40 reaches. FFU segments and the like can be applied as segments that can be cut by the cutter bit 52a attached to the cutter head 52 of the shield machine 40.

[0047] On the entrance 15 side of the bottom slab 13 of the intermediate shaft 10, a launch platform 16 is installed on which the shield tunneling machine 40 is placed and which aligns the shield tunneling machine 40 at approximately the same height level as the cutting wall 12.

[0048] In addition, a reaction wall 17 is installed behind the shield tunneling machine 40 in the intermediate shaft 10 when the shield tunneling machine 40 is advanced into the ground G, and a reaction beam 18 connected to the rear of the reaction wall 17 is connected to the rear wall 14.

[0049] That is, the tunnel construction method shown in the figure uses a shield machine 40, but the shield machine 40 is advanced into the ground G using the jacking method, and the tunnel is constructed using the jacking method. Here, if the ground behind the rear wall 14, which receives a reaction force when the shield machine 40 is advanced, needs to be reinforced to resist the acting reaction force, it is advisable to increase the strength of the ground behind the rear wall 14 by carrying out ground improvement work or the like.

[0050] The retrievable shield machine 40 is a slurry shield machine suitable for excavating at great depths, and excavates through ground G by filling a chamber behind the cutter head with slurry while resisting the soil and water pressure from the natural ground. Here, the shield machine may be an earth pressure shield machine in addition to a slurry shield machine.

[0051] The recoverable shield machine 40 has a recovery unit 50 and an outer shell 60. The outer shell 60 surrounds an inner shell 51 that constitutes the recovery unit 50 and is detachably attached to the inner shell 51. The outer shell 60 is, for example, a segment ring formed by assembling a plurality of steel segments in the circumferential direction.

[0052] The recovery unit 50 comprises an inner shell 51 made of, for example, a steel skin plate, an inner part 53 of a cutter head 52 located in front of the inner shell 51 in the excavation direction, a drive part 55 including a drive motor or the like that drives the cutter head 52 inside the inner shell 51, and a shield jack 57. The cutter head 52 has a number of cutter bits 52a on its front surface.

[0053] By having multiple shield jacks 57 in the circumferential direction, the direction of the shield machine 40 can be controlled by controlling the ON and OFF states of each shield jack 57 and by controlling the extension amount of each shield jack 57.

[0054] Cutter head 52 comprises an inner part 53 and an outer peripheral part 54 surrounding it, and the outer surface of outer peripheral part 54 is flush with the outer surface of outer shell 60 or protrudes further towards the natural ground than the outer surface of outer shell 60 when shield machine 40 is excavating, and is not included in recovery unit 50. After tunnel 30 is constructed, recovery unit 50 has inner shell 51 and outer shell 60 removed and passes through the inside of outer shell 60 and the subsequent tunnel box group 70A (see Figure 2) before being returned to intermediate shaft 10; therefore, outer peripheral part 54 of cutter head 52 interferes with outer shell 60, etc. during this movement, and is therefore not included in recovery unit 50.

[0055] Although not shown in the figure, the outer peripheral portion 54 is an arc-shaped segment divided circumferentially, which improves workability when removing it from the inner portion 53 or when attaching it to the inner portion 53 when regenerating the shield tunneling machine 40.

[0056] Furthermore, instead of the configuration in which outer portion 54 is detachable from inner portion 53 as in the illustrated example, the outer portion may be a copy cutter or the like that is radially extendable from inside the inner portion and is equipped with cutter bits on its front and radial end faces in the excavation direction, so that when the shield tunneling machine excavates, the outer portion extends from the inner portion, with its outer surface being flush with the outer surface of the outer shell or extending out further toward the natural ground than the outer surface of the outer shell, and is stored in the inner portion when the recovery unit is recovered. This configuration eliminates the need to remove the outer portion when recovering the recovery unit, and also eliminates the need to attach the outer portion when reconditioning the shield tunneling machine.

[0057] The multiple shield jacks 57 that make up the recovery unit 50 do not push the outer shell 60 that forms the tunnel 30 or the subsequent tunnel box 70, but instead push the thrust transmission member 80 that is located inside them and extends to the reaction wall 17 in the X1 direction, and the thrust transmission member 80 pushes the reaction wall 17 in the X2 direction, and the reaction force generated at this time causes the shield tunneling machine 40 to excavate in the X3 direction, which is the excavation direction.

[0058] The thrust transmission member 80 is formed of steel segments without a skin plate. A plurality of steel segments are suspended from the ground in the Z1 direction into the intermediate shaft 10, and assembled circumferentially inside the intermediate shaft 10 to form a segment ring, which is then installed on the reaction wall 17.

[0059] The shield tunneling machine 40 enters the ground G through the cutting wall 12 of the intermediate shaft 10, and while rotating the cutter head 52 in the X4 direction, the shield jack 57 pushes the thrust transmission member 80, which extends to the reaction wall 17 behind it, in the X1 direction, thereby drawing reaction force from the reaction wall 17 and propelling it forward in the excavation direction.

[0060] Here, inside the intermediate shaft 10, multiple tunnel boxes 70 (five in the illustrated example) are connected in sequence behind the outer shell 60 to form a tunnel box group 70A, and the outer shell 60 and the tunnel box group 70A are advanced as the shield tunneling machine 40 excavates.

[0061] As the shield tunneling machine 40 excavates inside the intermediate shaft 10, the steel segments that make up the thrust transmission member 80 are transported in the X5 direction to the inner shell 51 of the shield tunneling machine 40, and inside the inner shell 51, each steel segment is assembled circumferentially to form a new thrust transmission member 80 (ring), and the new thrust transmission member 80 (ring) is sequentially connected in front of the existing thrust transmission member 80.

[0062] The tunnel box 70 is provided with third filling holes 72, and a slippery material is filled between the tunnel box 70 and the ground G in the Y3 direction through these filling holes.

[0063] As shown in FIG. 3, the inner shell 51 has a first filling hole 51a and the outer shell 60 has a second filling hole 62, and the lubricant may be filled around the outer shell 60 through these filling holes.

[0064] Here, when steel segments are transported inside the shield tunneling machine 40 and new thrust transmission members 80 are assembled and installed, and the overall length of the thrust transmission members 80 is extended, as in conventional shield tunneling, only the shield jack in the assembly space for one piece of the divided steel segments is pulled, and the remaining shield jacks can receive reaction force from the thrust transmission members, so there is no risk of backing due to water pressure or soil pressure acting on the cutter head, etc. On the other hand, if a retrievable thruster is used, the thruster jack in the intermediate shaft must be retracted to secure space for assembling the steel shell. Therefore, the thruster cannot receive reaction force from the steel shell when assembling the steel shell, raising concerns about backing due to water pressure or soil pressure acting on the cutter head, etc. Therefore, each time the steel shell is assembled, it is necessary to temporarily fix a portion of the tunnel box group connected to the rear of the outer shell and the starting entrance, etc., by welding or other means, to prevent backing of the thruster, which delays the process.

[0065] As shown in Figure 3, before the shield machine 40 reaches the shield tunnel 20, an access partition wall 25 is constructed in the reach area, and the inside of the access partition wall 25 is filled with liquefied treated soil M.

[0066] The cutter head 52 cuts the cuttable segment 23 to reach the liquefied treated soil M inside the access partition 25, and the tip of the outer shell 60 is brought into a state where it can be joined with the entrance of the shield tunnel 20.

[0067] By injecting a chemical solution into the ground G in the Y1 direction through an injection port 26 provided on the outer periphery of the entrance of the shield tunnel 20, watertight measures are taken around the entrance of the shield tunnel 20 formed by the arrival of the shield tunneling machine 40.

[0068] In addition, backfill material is filled around the outer shell 60 and the tunnel box 70 in the Y2 and Y3 directions through the first filling hole 51a of the inner shell 51 and the second filling hole 62 of the outer shell 60, and further through the third filling hole 72 of the tunnel box 70, thereby taking similar water-stopping measures.

[0069] Next, as shown in Figure 4, a steel plate or the like is placed across both the entrance of the shield tunnel 20 and the tip of the outer shell 60, and the two are connected by welding or the like, thereby constructing a tunnel 30 (branch pipe) formed by the outer shell 60 and the tunnel box group 70A that connects the intermediate shaft 10 and the shield tunnel 20 (main pipe).

[0070] After the tunnel 30 is constructed, the inner shell 51 is removed from the outer shell 60 and the outer periphery 54 is removed from the cutter head 52, thereby preparing the recovery unit 50 to be recovered into the intermediate shaft 10.

[0071] As shown in Figure 5, after removing the reaction wall 17 and other components from the intermediate shaft 10, as well as various other equipment such as mud transport pipes, a receiving platform 19 is installed on the bottom slab 13. Furthermore, rails (not shown) are laid below the tunnel 30.

[0072] A center hole jack J through which a PC steel rod or the like is passed is fixed to the rear of the recovery unit 50, and the other end of the PC steel rod is fixed to the rear wall 14 of the intermediate shaft 10. By operating the center hole jack J and pulling it toward the rear wall 14 in the X6 direction, the recovery unit 50 moves along the rail toward the intermediate shaft 10 in the X7 direction.

[0073] As shown in FIG. 6, the recovery unit 50, which has been recovered into the intermediate shaft 10 and placed on the receiving platform 19, is pulled up to the ground in the Z2 direction.

[0074] On the ground, for example, at a work yard or assembly plant, a new outer shell 60 is attached to the outer periphery of the recovery unit 50, and the recovered outer periphery 54 is reattached to the outer periphery of the inner part 53 of the cutter head, thereby regenerating the shield tunneling machine 40.

[0075] According to the illustrated example of the shield tunneling machine 40 and the tunnel construction method using it, the recoverable shield tunneling machine 40 has a recovery unit 50 and an outer shell 60, and the recovery unit 50 includes an inner shell 51, a cutter head 52 located in front of the inner shell 51 in the excavation direction, a drive unit 55 that drives the cutter head 52 inside the inner shell 51, and a shield jack 57.As a result, many of the components of the shield tunneling machine 40 can be recovered as a single unit and reused, and when manufacturing a new shield tunneling machine 40, it is sufficient to attach a new outer shell 60 and the outer periphery 54 of the cutter head 52 to the outer periphery of the recovered recovery unit 50.This shortens the time required to manufacture a new shield tunneling machine 40, and prevents the overall construction period from becoming longer when reusing the shield tunneling machine 40 to construct multiple tunnels 30, thereby reducing construction costs.

[0076] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0077] 10: Starting section (intermediate shaft) 11: Front wall 12: Cutting wall 13: Bottom plate 14: Back wall 15: Entrance 16: Launch platform 17: Reaction wall 18:Reaction beam 19: Receiving stand 20: Reach section (shield tunnel, main pipe) 21: Segment ring 23: Cuttable segment 25: Reach bulkhead 26: Inlet 30: Tunnel (branch pipe) 40: Recoverable shield tunneling machine (shield tunneling machine) 50: Recovery unit 51: Inner shell 51a: 1st filling hole 52: Cutter head 52a: Cutter bit 53: Inner part 54: Outer periphery 55: Drive unit 57: Shield Jack 60: Outer shell 62:Second filling hole 70: Tunnel box 72: 3rd filling hole 70A: Tunnel box group 80: Thrust transmission member G: Underground (natural ground) S: Gap M: Liquefied soil J: Center hole jack

Claims

1. A recoverable shield tunneling machine that starts from a starting section, constructs a tunnel underground extending to a reaching section, and then can recover a portion of the tunnel for reuse, a collection unit and an outer shell; The recovery unit comprises: The excavation tunnel is provided with an inner shell, a cutter head located in front of the inner shell in the excavation direction, and a drive unit and a shield jack that drive the cutter head located inside the inner shell, the outer shell surrounds the inner shell and is detachably attached to the inner shell, A group of tunnel boxes consisting of a plurality of tunnel boxes is connected to the rear of the outer shell in the excavation direction and is advanced. a thrust transmission member that receives a reaction force from the launch section is disposed inside the tunnel box group and extends to the shield jack, A recoverable shield tunneling machine characterized in that the shield jack reaches the reach section by excavating using a reaction force from the thrust transmission member, and after a tunnel consisting of the outer shell and the group of tunnel boxes has been constructed, the inner shell is detached from the outer shell, making the recovery unit freely recoverable.

2. the thrust transmission member is formed of a steel segment without a skin plate; 2. The retrievable shield tunneling machine according to claim 1, wherein the steel segments are extended and lengthened as the shield tunneling machine excavates.

3. The cutter head has an inner part and an outer peripheral part around the inner part, and the inner part and the outer peripheral part are detachable, an outer peripheral surface of the outer peripheral portion is flush with the outer surface of the outer shell or protrudes laterally toward the natural ground beyond the outer surface of the outer shell when the shield machine excavates; 3. A recoverable shield tunneling machine according to claim 1 or 2, wherein the recovery unit does not include the outer periphery.

4. the cutter head has an inner portion and an outer periphery surrounding the inner portion; The outer peripheral portion is extendable and contractible in a radial direction from the inside of the inner portion, A recoverable shield tunneling machine as described in claim 1 or 2, characterized in that the outer peripheral portion extends from the inner portion when the shield tunneling machine is tunneling, so that its outer surface is flush with the outer surface of the outer shell or protrudes toward the ground to the side of the outer surface of the outer shell, and is stored in the inner portion when the recovery unit is recovered.

5. The inner shell is provided with a first filling hole, the outer shell is provided with a second filling hole, and the tunnel box is provided with a third filling hole; A retrievable shield tunneling machine as described in claim 1 or 2, characterized in that a lubricant is injected around the outer shell and / or around the tunnel box through the first filling hole and the second filling hole, and / or through the third filling hole during excavation, and backfill material is filled in after excavation is completed.

6. A tunnel construction method using a retrievable shield machine, in which a part of the shield machine is retrievable, is started from a starting point, a tunnel is constructed underground extending to a reaching point, and then a part of the shield machine is retrievable for reuse, the recoverable shield machine includes a recovery unit and a hull; The recovery unit comprises: The excavation tunnel is provided with an inner shell, a cutter head located in front of the inner shell in the excavation direction, and a drive unit and a shield jack that drive the cutter head located inside the inner shell, the outer shell surrounds the inner shell and is detachably attached to the inner shell, A tunnel construction method using a recoverable shield machine, characterized in that the shield machine is launched from the launch section, tunnel boxes are connected in sequence behind the outer shell in the excavation direction, and thrust transmission members that receive reaction force from the launch section are arranged inside the tunnel boxes and connected in sequence, the shield jack receives reaction force from the thrust transmission members and excavates, and the shield machine reaches the reach section, thereby constructing a tunnel formed by a tunnel box group consisting of a plurality of tunnel boxes and the outer shell, and then detaching the inner shell from the outer shell and recovering the recovery unit.

7. 7. A tunnel construction method using a retrievable shield machine as described in claim 6, characterized in that a new outer shell is attached to the recovered unit to form a new shield machine, and a separate tunnel is constructed using the new shield machine.

8. It is a shield tunnel with an intermediate shaft at the starting point and a main tunnel at the end point. Assembling the tunnel box in the intermediate shaft; The thrust transmission member receives a reaction force from a reaction force frame located inside the intermediate shaft, A tunnel construction method using a retrievable shield machine as described in claim 6 or 7, characterized in that when the recovery unit is recovered, rails are laid below the constructed tunnel and the recovery unit is transported along the rails to the intermediate shaft and recovered.

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