JP2015094167A - Concrete placing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a placing method which enables placing of a covering concrete of high quality.SOLUTION: A covering concrete placing method performs placing of a covering concrete of a tunnel by using a form for tunnel covering. A top end part 1a of a center 1 is provided with a plurality of blow placing holes H. There are included a concrete guiding-in step for guiding-in a concrete into a placing space R through any one of the plurality of blow placing holes H, and a guiding-in hole switching step for switching so that blow placing holes H that guide in the concrete among the plurality of blow placing holes H are circulated in a regular sequence.

Description

  The present invention relates to a concrete placing method for placing tunnel lining concrete using a tunnel lining formwork.

  Conventionally, as a technique in such a field, a method for placing lining concrete described in Patent Document 1 below is known. In this placing method, when placing the top end portion of the lining concrete, the concrete is introduced into the placement space at the top end portion from the concrete outflow portion provided at the top of the tunnel lining formwork. .

JP 2000-257391 A

  However, in the above placement method, a part of the concrete flows for a long distance from the concrete outflow portion to the corner of the mold in the placement space. And while the concrete flows over a long distance, there is a tendency for moisture and aggregates in the concrete to separate, and as a result, the occurrence of bleeding or the like may cause the quality of the lining concrete to deteriorate. is there. In this type of lining concrete, it is required to reduce the material separation of the concrete as described above and further improve the concrete quality.

  An object of the present invention is to provide a placing method that enables placement of high-quality lining concrete.

  The lining concrete placing method of the present invention is a concrete placing method for placing tunnel lining concrete using a tunnel lining formwork, and is provided at the top end of the tunnel lining formwork. A plurality of blowing-up holes are provided, and a concrete introduction process for introducing concrete into the placement space through any one of the plurality of blowing-up holes, and a blowing-up process for introducing concrete among the plurality of blowing-up holes. An introduction hole switching step for switching the holes to circulate in a regular order.

  In this concrete placement method, the concrete is introduced into the placement space from the plurality of blowing-up holes, so that the flow distance of the concrete introduced from each of the blowing-up holes can be kept small. Therefore, in the placement space in the vicinity of the top end, the flow distance of the concrete is suppressed as a whole, and as a result, the material separation (bleeding or the like) of the concrete is suppressed. Therefore, it is possible to place high-quality lining concrete.

  In addition, since the concrete in the placement space near the top end can be pressurized through each blow-up placement hole, the pressure acting on each part of the concrete at the time of pressurization can be made uniform. Homogenization of concrete can be achieved.

  More specifically, the method for placing lining concrete according to the present invention includes a concrete pump for pumping concrete into the blow-up hole in the concrete introduction process, and a concrete from the concrete pump in the introduction hole switching process. It is also possible to use a branch switching means for selectively switching the pumping destination of a plurality of blowing holes and a control unit for controlling the branch switching means based on the concrete pumping amount by the concrete pumping machine. .

  Further, the branch switching means is connected to a first stage switching machine having a concrete inlet connected to the concrete pressure feeder and a plurality of selectively switched concrete outlets, and one concrete outlet of the plurality of concrete outlets. A first rear-stage switching machine having a second-stage concrete inlet, a plurality of second-stage concrete outlets that are selectively switched, and another second-stage concrete inlet connected to another concrete outlet of the plurality of concrete outlets; A second rear-stage switching machine having a plurality of other rear-stage concrete outlets that can be selectively switched may be provided.

  In this case, since the switching of the concrete pumping destination is executed in two stages, that is, the front stage switching machine and the first and second rear stage switching machines, for example, while the concrete is being sent to the first rear stage switching machine. It is possible to alternately perform operations such as driving the second rear-stage switching machine and driving the first rear-stage switching machine while the concrete is being sent to the second rear-stage switching machine. Therefore, it is possible to eliminate waste of driving time in the front-stage switching machine and the first and second rear-stage switching machines.

  Further, in the concrete placing method of the present invention, a concrete pumping machine for pumping concrete into the blowing-up hole in the concrete introduction process, and one end connected to the concrete pumping machine and the other end having a plurality of blowing-up holes. A flexible pipe in which concrete is pumped into the interior, a switching means for selectively switching the mounting destination of the flexible pipe among a plurality of blowing holes in the introduction hole switching step, and a concrete pump It is good also as using the control part which controls a switching means based on the amount of concrete pumped by.

  In this case, since the attachment destination of the flexible pipe into which the concrete is pumped into the inside is selectively switched between the plurality of blowing-up holes, the concrete is fed into each of the blowing-up holes by a common flexible pipe. Will be done. This shortens the time that the concrete waits inside the flexible pipe, and can prevent the concrete from hardening inside the flexible pipe.

  In any of the above placement methods, in the concrete introduction process, the air removal process for discharging air from the placement space accompanying the introduction of the concrete through the air vent pipe disposed in the placement space, and the placement space It is good also as performing the compaction process which compacts the concrete introduced into the placement space by the vibrator previously installed in the.

  The concrete introduction process and the introduction hole switching process are ended when the concrete detection sensor installed at a predetermined height in the placement space detects concrete, and after the concrete introduction process and the introduction hole switching process. The concrete introduction pipe is extended upward from the end placement hole arranged on the most existing side among the plurality of blow-up placement holes, and the concrete unfilled space left in the upper part of the placement space is passed through the concrete introduction pipe. It is good also as providing the concrete filling process which introduces concrete.

  The lining concrete placement method of the present invention is a lining concrete placement method using a tunnel lining formwork, and a plurality of blow-up placement holes are provided at the top end portion of the tunnel lining formwork. It is provided, It is provided with the concrete introduction process which introduce | transduces concrete into a placement space simultaneously in parallel from several blow-up placement holes.

  According to the concrete placement method of the present invention, it is possible to place high-quality lining concrete.

It is a perspective view which shows the centle used for the concrete placement method of embodiment of this invention. It is sectional drawing of the centle and tunnel shown in FIG. It is a figure which shows the concrete placement apparatus used for the concrete placement method of 1st Embodiment of this invention. It is sectional drawing which took the tunnel sectional view in the concrete placement method of embodiment. FIG. 5 is an enlarged cross-sectional view of the top end portion taken in a vertical cross section (V-V cross section in FIG. 4) in the tunnel longitudinal direction in one step of the concrete placing method of the embodiment. FIG. 5 is an enlarged cross-sectional view of the top end portion taken in a vertical cross section (V-V cross section in FIG. 4) in the tunnel longitudinal direction in one step of the concrete placing method of the embodiment. (A) is the expanded sectional view of the top end which took the vertical section (VV section of Drawing 4) of the tunnel longitudinal direction in one process of the concrete placement method of an embodiment, (b) is the bb It is sectional drawing. FIG. 5 is an enlarged cross-sectional view of the top end portion taken in a vertical cross section (V-V cross section in FIG. 4) in the tunnel longitudinal direction in one step of the concrete placing method of the embodiment. FIG. 5 is an enlarged cross-sectional view of the top end portion taken in a vertical cross section (V-V cross section in FIG. 4) in the tunnel longitudinal direction in one step of the concrete placing method of the embodiment. It is a figure which shows the concrete placement apparatus used for the concrete placement method of 2nd Embodiment of this invention. It is a figure which shows the concrete placement apparatus used for the concrete placement method of 3rd Embodiment of this invention.

  Hereinafter, embodiments of a concrete placing method according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, the concrete placement apparatus 90 (FIG. 3) used for the concrete placement method of this embodiment will be described. As shown in FIGS. 1 to 3, when placing lining concrete on the wall surface 101 of the tunnel 100, a centle (tunnel lining formwork) 1 is used as a formwork. The wall surface 101 is the surface of the primary lining part which consists of preformed shotcrete. The center 1 is provided with an outer surface 2 (a natural mountain side surface) curved along the wall surface 101, and the center 1 is supported by the gantry 3. A rail 103 is laid in the tunnel 100, and the centle 1 and the gantry 3 can move on the rail 103 in the axial direction (longitudinal direction) of the tunnel 100.

  The length of the centle 1 in the tunnel longitudinal direction is, for example, 10.5 m. A gap between the wall surface 101 and the outer surface 2 becomes a placement space R in which concrete is placed. In order to partition this placement space R in the longitudinal direction of the tunnel, a number of wife mold frame plates 5 are arranged in the circumferential direction of the tunnel and are detachably attached to the end of the center 1 on the wife side. Except for the configuration of the top end of the center 1 that will be described later, since the center 1 and the gantry 3 may be known ones, a more detailed description of the center 1 and the gantry 3 is omitted.

  The top end portion 1a of the center 1 is provided with a plurality of blowing up holes H (in the present embodiment, eight) for introducing concrete into the placing space R. In addition, when distinguishing each of the plurality of blowing up holes H, they are referred to as blowing up holes H1, H2,..., H8 in order from the existing side (wellhead side) to the wife side (face side). The blowing holes H <b> 1 to H <b> 8 are arranged at equal intervals in the tunnel longitudinal direction on the highest bus line of the outer surface 2. Each blowing-up hole H can be opened and closed by a known shutter mechanism (not shown).

  As shown in FIG. 3, the concrete placing device 90 includes the above-described centle 1, a concrete feeder 21 for feeding concrete into each of the blow-up placement holes H, and a concrete delivery destination from the concrete feeder 21. Are provided with a branch switching system (branch switching means) 23 for selectively switching between the blow-up driving holes H1 to H8, and a computer (control unit) 25 for controlling the branch switching system 23.

  The concrete pumping machine 21 is, for example, a type that pumps concrete by a reciprocating movement of a piston, and can be one that is mounted on a known concrete pump truck.

  The branch switching system 23 includes one upstream switching device 31 and two downstream switching devices 32 and 33. The front-stage switching machine 31 has a concrete inlet 31a connected to the concrete pressure feeder 21 and two concrete outlets 31b and 31c. The pre-stage switching machine 31 includes a known flow path switching mechanism that is driven under the control of the computer 25, and can selectively switch the discharge destination of the concrete fed from the concrete inlet 31a to the concrete outlets 31b and 31c. . That is, the concrete sent from the concrete pressure feeder 21 to the upstream switching machine 31 is selectively discharged to either the concrete outlet 31b or 31c based on the control of the computer 25.

  The rear stage switching machine (first rear stage switching machine) 32 includes a concrete inlet 32a connected to the concrete outlet 31b of the front stage switching machine 31, and four concrete outlets 32b, 32c, 32d, and 32e. The post-stage switching machine 32 includes a known flow path switching mechanism that is driven under the control of the computer 25, and selectively switches the discharge destination of the concrete fed from the concrete inlet 32a to any one of the concrete outlets 32b to 32e. be able to. That is, the concrete sent from the concrete outlet 31 b of the front-stage switching machine 31 to the rear-stage switching machine 32 is selectively discharged to any of the concrete outlets 32 b to 32 e based on the control of the computer 25. The concrete outlets 32b, 32c, 32d, and 32e are connected to the blowing holes H1, H3, H5, and H7 through the transport pipes P1, P3, P5, and P7, respectively.

  The rear stage switching machine (second rear stage switching machine) 33 has a concrete inlet 33a connected to the concrete outlet 31c of the front stage switching machine 31, and four concrete outlets 33b, 33c, 33d, and 33e. The post-stage switching machine 33 includes a known flow path switching mechanism that is driven under the control of the computer 25, and selectively switches the destination of the concrete fed from the concrete inlet 33a to any one of the concrete outlets 33b to 33e. be able to. That is, the concrete sent from the concrete outlet 31 c of the front stage switching machine 31 to the rear stage switching machine 33 is selectively discharged to any of the concrete outlets 33 b to 33 e based on the control of the computer 25. The concrete outlets 33b, 33c, 33d, and 33e are connected to the blowing holes H2, H4, H6, and H8 through the transport pipes P2, P4, P6, and P8, respectively.

  With the branch switching system 23 as described above, under the control of the computer 25, the concrete pumping destination from the concrete pumping machine 21 can be switched to any of the blow-up driving holes H1 to H8.

  The computer 25 transmits a flow path switching signal to the upstream switching device 31 and the downstream switching devices 32 and 33 in accordance with a predetermined program prepared in advance. Specifically, the computer 25 counts the number of strokes of the pumping piston of the concrete pumping machine 21, and switches the blow-up hole H of the concrete pumping destination for each predetermined number of strokes. Here, from the existing concrete 110 side (existing side) toward the end form plate 5 side (wife side), the blow-up driving holes H1, H2, H3,..., H7, H8, H1, H2,. The concrete pumping destinations are sequentially switched so as to circulate through the blowing holes H1 to H8. Thereby, almost the same amount of concrete is sequentially introduced into the placement space R through the blow-up placement holes H1 to H8.

  In addition, since the switching of the concrete pumping destination is executed in two stages of the front-stage switching machine 31 and the rear-stage switching machines 32 and 33, for example, the concrete is sent to the rear-stage switching machine 32 while the concrete is being sent to the rear-stage switching machine 32. It is possible to alternately perform operations such as driving the flow path switching mechanism 33 and driving the flow path switching mechanism of the rear stage switching machine 32 while the concrete is being sent to the rear stage switching machine 33. Therefore, waste of driving time of the flow path switching mechanism in the upstream switching device 31 and the downstream switching devices 32 and 33 can be omitted. In the present embodiment, the front-stage switching device 31 is a two-port switching device, and the rear-stage switching devices 32 and 33 are four-port switching devices. However, the number of switching ports of each switching device 31 to 33 should be changed as appropriate. Can do.

  Next, a method for placing lining concrete according to this embodiment using the above-described concrete placing apparatus 90 will be described.

  First, as shown in FIGS. 4 and 5, the centle 1 is installed in the face side area adjacent to the existing lining concrete 110. Then, as shown in FIG. 4, concrete C <b> 2 is placed in the lower space R <b> 2 excluding the top end space R <b> 1 in the placement space R (lower space placing step). Since the concrete C2 placement method in the lower space R2 is exactly the same as the known lining concrete placement method, detailed description thereof is omitted. Here, the lower space R2 has an upper end at a position slightly lower than the blowing hole H, and the concrete C2 does not reach the blowing hole H. That is, the top end space R1 is a space above a position slightly below the blasting hole H, and each blasting hole H1 is exposed to the top end space R1.

  Thereafter, concrete placement of the top end space R1 in the placement space R is performed as follows (top end space placement step). In the top end space placing step, as shown in FIG. 5, a drawing vibrator 41, a concrete detection sensor 42, and an air vent pipe 43 are installed in advance in the top end space R1. The extraction vibrator 41 is initially installed on the existing side of the top end space R1, and vibrates while being pulled out to the wife side by a wire or the like. Thereby, the concrete of the whole top end space R1 can be compacted. The concrete detection sensor 42 is installed at a predetermined height in the top end space R1 so as to be suspended from the upper surface of the wall surface 101 of the tunnel 100, for example, and detects concrete. In addition, it is preferable to install a plurality of concrete detection sensors 42 in the axial direction of the tunnel or the height direction of the cross section.

  The air vent pipe 43 extends in the longitudinal direction of the tunnel of the centle 1, and can send the air in the top end space R <b> 1 to the outside of the wife mold frame plate 5 through the pipe side surface. In the drawings other than FIG. 5, the drawing vibrator 41, the concrete detection sensor 42, and the air bleeding pipe 43 may be omitted as appropriate.

  At the time of placing concrete in the top end space R1, first, the concrete pumping machine 21 is driven, and concrete is introduced into the top end space R1 through each of the blow-up placement holes H (concrete introduction step). At this time, while driving the concrete pumping machine 21, the computer 25 appropriately transmits a drive signal to the branch switching system 23, and circulates the blowing holes H <b> 1 to H <b> 8 for each predetermined number of strokes of the concrete pumping machine 21. Thus, the concrete pressure destination is switched one by one (introduction hole switching step). In addition, while concrete is being introduced from one blowing hole H, the other blowing holes H may be closed by a shutter mechanism (not shown).

  Then, as shown in FIG. 6, almost equal amounts of concrete C are placed in the order of the blow-up holes H1, H2,... H8, H1, H2,. It is introduced into the subspace R1. For example, if the capacity of the concrete pumping machine 21 is about 50 L per stroke, the driving time of one stroke is 2 seconds, and the pumping destination is switched every five strokes of the concrete pumping machine 21, about 250 L of concrete C is obtained. Every 10 seconds, the air is sequentially fed into the top end space R1 through the blowing holes H1 to H8. At this time, with the introduction of the concrete C, air in the top end space R1 is smoothly discharged to the wife side through the air vent pipe 43 (air venting process), so that air remains in the top end space R1. The possibility is reduced.

  When the concrete C introduced through the blow-up driving hole H is filled to a predetermined height, the concrete detection sensor 42 detects the concrete C. When the concrete detection sensor 42 detects concrete, the concrete introduction process and the introduction hole switching process are finished. Thereafter, the pulling vibrator 41 (FIG. 5) is driven and pulled toward the end frame 5 so that the entire concrete in the top end space R1 is compacted (compacting process). . Through the above steps, as shown in FIG. 7, the top end space R1 is filled with concrete leaving a slight gap at the upper end. Hereinafter, the gap portion is referred to as a concrete unfilled space R3.

  Subsequently, as shown in FIG. 8, the concrete introduction pipe 47 is extended upward from the blowing placement hole H1 (end placement hole) arranged on the most existing side among the blowing placement holes H1 to H8, The upper end of the concrete introduction pipe 47 is protruded into the concrete unfilled space R3. It is to be noted that the introduction pipe that can be expanded and contracted up and down from the blowing hole is known, and a known one can be adopted as the concrete introduction pipe 47. Then, when the concrete from the concrete pumping machine 21 is sent to the blow-up driving hole H1, as shown in FIG. 9, the concrete C ′ flows toward the end form plate 5 in the concrete unfilled space R3, The unfilled space R3 is filled with concrete C ′ (concrete filling step). At this time, if the signal from the concrete detection sensor 42 (FIG. 5) is confirmed, it can be confirmed that the concrete C 'is completely filled in the unfilled space R3. Thereafter, the concrete in the top end space R1 is pressed in sequence through each of the blow-up holes H1 to H8 (concrete pressurizing step) in order to densely close the concrete in the top end space R1. Can be filled.

  Thus, the concrete C is filled in the entire placement space R. Thereafter, the centle 1 is removed from the mold after a predetermined curing period, whereby a lining concrete portion having a length corresponding to the length of the centle 1 (for example, about 10.5 m) is completed. Then, the lining concrete of the tunnel 100 is completed by repeating the construction of the lining concrete portion over the entire length of the tunnel 100.

  Then, the effect by the concrete placement method mentioned above is demonstrated.

  In the concrete placement method described above, concrete is introduced into the top end space R1 using a plurality of blow-up placement holes H1 to H8 and changing the blow-up placement holes H1 to H8 for introducing concrete one by one in order. doing. For example, when concrete is introduced from the blow-up placement hole H3, the concrete rises at a position immediately above the blow-up placement hole H3 to form a concrete pile Q3. Next, when the concrete is introduced from the blowing-up hole H4, the concrete rises at a position immediately above the blowing-up hole H4 to form a concrete peak Q4. The concrete pile Q3 gradually collapses and the concrete hangs down. However, the concrete hanging from the mountain Q3 is hindered from flowing in the tunnel longitudinal direction by the adjacent mountain Q4 or the concrete layer hanging from the mountain Q4, and almost droops in the circumferential direction of the tunnel and flows.

  As in the above example, the concrete C introduced from each of the blowing holes H1 to H8 interferes with movement in the tunnel longitudinal direction, and flows almost only in the circumferential direction of the tunnel for a short distance. . That is, for example, if the concrete C introduced from the blow-up hole H1 flows to the vicinity of the end form frame plate 5, the flow distance of the concrete is longer than the length of the centle 1 (for example, 10.5 m). Reach. On the other hand, if the concrete C introduced from each blowing hole H1 moves in the tunnel circumferential direction in the top end space R1, the moving distance is considered to be about 2 m at the maximum.

  Therefore, there is almost no component that flows over a long distance in the concrete C introduced into the top end space R1, and the flow distance of the concrete is kept small as a whole. As a result, the concrete C in the top end space R1 is reduced. Material separation (bleeding, etc.) is suppressed. Therefore, according to the concrete placement method described above, it is possible to place high-quality lining concrete.

  Moreover, since the concrete in the top end space R1 can be pressurized from each of the blowing holes H1 to H8, the pressure acting on each part of the concrete in the top end space R1 can be made uniform. As a result, it is possible to homogenize the concrete in the top end space R1.

  Conventionally, tunnel lining concrete is placed by introducing concrete from the existing side and pushing it in the axial direction toward the wife side. Instead, the blowing holes H1 to H8 for introducing the concrete are switched in a regular order (that is, the concrete may be introduced from the existing side after the concrete is introduced from the wife side). However, it is averaged in the height direction by driving. In the case of conventional one-pressing, unfilled locations such as air and water pools can be suppressed, and the concrete to be pumped can be driven continuously, thus increasing the amount of placement and saving labor. However, due to the long distance of the concrete flow, there are problems such as material separation and bleeding. On the other hand, in the concrete placing method described above, the concrete is placed by introducing the concrete into the placement space while switching so that the blow-up placement holes H1 to H8 for introducing the concrete are circulated in a regular order. Since it can be averaged in the height direction of the installation space, the quality of the concrete can be improved.

  In the concrete placement method, the unfilled space R3 is left in the concrete introduction process and the introduction hole switching process, and then the unfilled space R3 is filled in the concrete filling process. Here, it is also conceivable that bleeding water has accumulated on the upper surface of the concrete C when the concrete introduction process and the introduction hole switching process are completed. However, in the concrete filling process, the concrete C ′ from the concrete introduction pipe 47 flows from the existing side to the wife side in the unfilled space R3. Therefore, even if bleeding water is accumulated, the bleeding water is transferred to the concrete C ′. It is swept away and discharged from the top end space R <b> 1 through the gap between the end form plates 5. Further, in the concrete filling process, the concrete C ′ flows in almost one direction through the unfilled space R3 that is a narrow gap, so that it is considered that the material separation of the concrete C ′ hardly occurs.

(Second Embodiment)
Then, 2nd Embodiment of the concrete placement method of this invention is described. In the present embodiment, the same or equivalent components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  In the concrete placement method of the present embodiment, a concrete placement device 290 is used. As shown in FIG. 10, the concrete placement device 290 includes a front-stage pipe branching portion 231 instead of the front-stage switching machine 31 provided in the concrete placement device 90 described above. The pre-stage pipe branching portion 231 splits the concrete pumped from the concrete pump 21 into the two concrete outlets 31b and 31c.

  Further, the concrete placing apparatus 290 includes rear-stage pipe branch portions 232 and 233 instead of the two rear-stage switching machines 32 and 33. The rear-stage pipe branching portion 232 further divides the concrete from the concrete outlet 31b of the front-stage pipe branching portion 231 into four parts, and the blow-up placing holes H1, H3, respectively, via the transport pipes P1, P3, P5, P7, respectively. Send to H5 and H7. Similarly, the rear pipe branching portion 233 further divides the concrete from the concrete outlet 31c of the front pipe branching portion 231 into four parts, respectively, and blows up holes H2 through the transport pipes P2, P4, P6, and P8, respectively. , H4, H6, H8. The front-stage pipe branching portion 231 and the rear-stage pipe branching portions 232 and 233 are not provided with a flow path switching mechanism, and simply branch the concrete conveyance flow path into two or four.

  In the concrete introduction process in the concrete placement method of the present embodiment, the concrete placement apparatus 290 is used to simultaneously introduce concrete into the top end space R1 from the blow-up placement holes H1 to H8. Also by the concrete placement method of such a form, the effect similar to the above-mentioned 1st Embodiment is show | played. In this embodiment, the upstream pipe branching section 231 branches the transport path into two, and the rear-stage pipe branching sections 232 and 233 split the transport path into four, but each of the pipe branching sections 231 to 233 The number of branches of the conveyance path in can be changed as appropriate.

(Third embodiment)
Then, 3rd Embodiment of the concrete placement method of this invention is described. In the present embodiment, the same or equivalent components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  In the concrete placement method of the present embodiment, a concrete placement device 390 is used. As shown in FIG. 11, the concrete placing device 390 includes a single flexible hose (flexible pipe) 51 instead of the branch switching system 23 provided in the concrete placing device 90 described above. Yes.

  The hose 51 has a hose body 52 having one end connected to the concrete pumping machine 21 and a nozzle 53 connected to the other end of the hose body 52, and the concrete pumped from the concrete pumping machine 21 is inside thereof. It flows through. The tip of the nozzle 53 has a structure that can be attached to and detached from the blowing holes H1 to H8. Under the control of the computer 25, attachment and removal to the blowing holes H1 to H8 are performed.

  The nozzle 53 is placed on a carriage (switching means) 60, and the carriage 60 can be moved to a position corresponding to each of the blowing holes H1 to H8 by a known method under the control of the computer 25. . In addition, in FIG. 11, a mode that the trolley | bogie was located in the position corresponding to the blowing up hole H5 is shown. The hose 51 has a sufficient length such that the carriage 60 can move without difficulty between the blowing holes H1 to H8.

  In the concrete introduction process in the concrete placing method of the present embodiment, the concrete placing device 390 is used, and the concrete is removed from the blow-up placement holes H1 to H8 in the regular order similar to the first embodiment. Introduced into R1. At this time, the computer 25 transmits a movement signal to the carriage 60 according to a predetermined program prepared in advance. Then, the trolley | bogie 60 moves to the position corresponding to the blowing up hole which should pump concrete, and the nozzle 53 is attached to the blowing up hole. When the predetermined amount of concrete has been pumped, the pumping is stopped and the nozzle 53 is removed from the blow-up driving hole. Based on the movement signal from the computer 25, the carriage 60 moves to a position corresponding to the blow-up hole to which concrete is to be pumped next.

  According to this embodiment, since the attachment destination of the hose 51 into which concrete is pumped into the interior is selectively switched between the plurality of blowing holes H1 to H8, the concrete to each of the blowing holes H1 to H8 Is fed by the common hose 51. In the first embodiment, the inside of the transfer pipes P1 to P8 is filled with concrete that waits for the order of pumping during placement, and the concrete may be hardened while waiting for the order of pumping. In this embodiment, the time that the concrete waits inside the hose 51 is short, and the concrete is prevented from hardening inside the hose 51.

  Further, when the concrete is pumped through the transport pipe P as in the first embodiment, a lubricating film is formed inside the transport pipe P or the internal seal is secured to ensure the fluidity of the concrete prior to the start of the pumping. It is necessary to ensure sex. Therefore, by feeding mortar or the like before the concrete is pumped, it is possible to prevent the concrete from being blocked during pumping and being unable to be pumped or the quality of the concrete from being deteriorated. In this respect, according to the present embodiment, since the pumping of the concrete is performed by the common hose 51, such a prior operation for each transport pipe P is unnecessary, so that the efficiency of the placing work and the lining concrete are increased. The quality of the product can be improved.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and may be modified without changing the gist described in each claim.

  For example, in the first embodiment and the third embodiment, when circulating the blowing up holes H1 to H8 for introducing concrete in a regular order, the blowing up holes H1, H2,... H8, H1, H2,. However, instead of this, for example, H1, H8, H3, H6, H5, H4, H7, H2, H1, H8,... , H5, H6, H3, H2, H7, H1, H8, H4, H5,... And may be circulated in a regular order such as the order from the center toward the existing side and the wife side. Further, it may be circulated in the order of H1, H3, H5, H7, H2, H4, H6, H8, H1, H3,.

  In the embodiment, after leaving the unfilled space R3 by the concrete introduction process and the introduction hole switching process, the concrete is filled in the unfilled space R3 in the concrete filling process, but only the concrete introduction process and the introduction hole switching process. Thus, the top end space R1 may be completely filled, and the concrete filling step may be omitted. Further, the number of blow-up driving holes H is not limited to eight and can be adjusted as appropriate. In addition, from the viewpoint of shortening the flow distance of the concrete in the top end space R1, it is preferable that the number of blowing-up holes H is three or more. Further, as in the first embodiment, it is not essential to control the branch switching system 23 with the computer 25, and the branch switching system 23 may be manually operated.

  In the embodiment, the pullout vibrator 41 is used as the compacting process. However, instead of this, a formwork vibrator may be installed on the inner surface of the top end portion 1a of the formwork (centre 1). In this case, the form vibrator is installed in the vicinity of the blowing hole H at a plurality of locations along the arrangement of the blowing holes H1 to H8 (along the tunnel axis direction). It is preferable that 1 to 4 rows are installed in total. And it is preferable to switch the vibrator which drives a several formwork vibrator, whenever it switches the blowing hole which introduces concrete.

  DESCRIPTION OF SYMBOLS 1 ... Centle (form for tunnel lining), 1a ... Central top part, 21 ... Concrete pumping machine, 23 ... Branch switching system (branch switching means), 25 ... Computer (control part), 31 ... Previous stage switching machine 31a ... Concrete inlet, 31b, 31c ... Concrete outlet, 32 ... Rear-stage switching machine, 32a ... Concrete inlet, 32b-32e ... Concrete outlet, 33 ... Rear-stage switching machine, 33a ... Concrete inlet, 33b-33e ... Concrete outlet, 41 DESCRIPTION OF SYMBOLS ... Pull-out vibrator, 42 ... Concrete detection sensor, 43 ... Air vent pipe, 47 ... Concrete introduction pipe, 51 ... Hose (flexible pipe), 60 ... Bogie (switching means) H, H1-H8 ... Blow-up driving hole, H1 ... Blow-up casting hole (end casting hole), R ... Casting space, R1 ... Top edge (casting space), R3 ... Empty without filling concrete while.

Claims (7)

A concrete placing method for placing tunnel lining concrete using a tunnel lining formwork,
A plurality of blowing holes are provided at the top end of the tunnel lining formwork,
A concrete introduction step of introducing concrete into the placement space through any of the plurality of blow-up placement holes;
A concrete placement method comprising: an introduction hole switching step for switching the blowup placement holes for introducing the concrete among the plurality of blowup placement holes to circulate in a regular order. A concrete pumping machine for pumping concrete into the blowing hole in the concrete introduction step;
A branch switching means for selectively switching a concrete pumping destination from the concrete pumping machine between the plurality of blow-up driving holes in the introduction hole switching step;
The concrete placement method according to claim 1, further comprising: a control unit that controls the branch switching unit based on a pumping amount of the concrete by the concrete pumping machine. The branch switching means includes
A pre-stage switching machine having a concrete inlet connected to the concrete pressure feeder and a plurality of concrete outlets selectively switched;
A first rear-stage switching machine having a rear-stage concrete inlet connected to one concrete outlet of the plurality of concrete outlets, and a plurality of rear-stage concrete outlets that are selectively switched;
A second rear-stage switching machine having another rear-stage concrete inlet connected to another concrete outlet of the plurality of concrete outlets, and a plurality of other rear-stage concrete outlets that are selectively switched. The concrete placement method according to claim 2, wherein: A concrete pumping machine for pumping concrete into the blowing hole in the concrete introduction step;
One end is connected to the concrete pumping machine and the other end can be attached to the plurality of blow-up driving holes, and a flexible pipe through which the concrete is pumped,
In the introduction hole switching step, switching means for selectively switching the attachment destination of the flexible pipe among the plurality of blowing holes,
The concrete placement method according to claim 1, further comprising: a control unit that controls the switching unit based on a pumping amount of the concrete by the concrete pumping machine. In the concrete introduction process,
An air venting process for discharging air from the placement space accompanying the introduction of concrete through an air vent pipe arranged in the placement space;
A compaction process for compacting the concrete introduced into the placement space by a vibrator previously installed in the placement space;
The concrete placing method according to any one of claims 1 to 4, wherein: The concrete introduction step and the introduction hole switching step are terminated when a concrete detection sensor installed at a predetermined height in the placement space detects concrete,
After the concrete introduction step and the introduction hole switching step,
Extending the concrete introduction pipe upward from the end placement hole arranged on the most existing side among the plurality of blow-up placement holes,
The concrete placement process according to any one of claims 1 to 5, further comprising a concrete filling step of introducing concrete into the concrete unfilled space left above the placement space through the concrete introduction pipe. Installation method. A method of placing lining concrete using a tunnel lining formwork,
A plurality of blowing holes are provided at the top end of the tunnel lining formwork,
A concrete placement method comprising a concrete introduction step of simultaneously introducing concrete into the placement space from the plurality of blow-up placement holes simultaneously.

Images