Method for Removing Tunnel Ceiling Portion

Abstract

To provide a tunnel ceiling part removal method allowing for securely removing many existing ceiling boards that are continuously installed in axial direction of a tunnel and integrally fixed in a state of being arranged in a width direction within a predetermined time period.SOLUTION: A tunnel ceiling part removal method comprises: a ceiling board replacing step to repeatedly execute a work of removing a portion of existing ceiling boards 11 and replacing the existing ceiling boards with replacement pieces 14 that are lighter than the existing ceiling boards within a predetermined time during which use of a tunnel 10 is limited until all existing ceiling boards 11 in a predetermined construction area R are replaced with the replacement pieces 14; and a replacement piece removing step to execute a work to remove all replacement pieces 14 that were replaced within a predetermined time during which use of the tunnel 10 is interrupted.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for removing a tunnel ceiling portion, and more particularly, to a method for removing a tunnel ceiling portion that enables a plurality of rectangular existing ceiling plates forming the tunnel ceiling portion to be removed by work within a predetermined time.

Background Art

[0002] A ceiling portion formed by arranging a large number of ceiling plates, preferably precast concrete ceiling plates, manufactured in advance in a factory or the like in the continuous arrangement direction so as to cover the top end portion of a tunnel such as a road tunnel from below is provided in many tunnels. However, a ceiling portion formed by such an existing precast concrete ceiling plate may need to be removed due to aging or reconstruction of the tunnel. For this reason, various methods for removing a ceiling portion formed by such an existing ceiling plate (existing ceiling plate) have been developed (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] On one hand, in the case of a tunnel having a considerable tunnel width, such as a road tunnel with multiple lanes constituting a trunk road, linear support steel materials (linear support steel bars) that are supported on the upper part of the tunnel lining structure forming the inner wall surface of the tunnel and extend parallel to the axial direction of the tunnel are installed in multiple rows at intervals. The ceiling part is formed by placing and joining, for example, preferably the both side ends of a large number of precast concrete ceiling slabs having a rectangular planar shape on these linear support steel bars extending in the axial direction of the tunnel, so that the large number of ceiling slabs are continuously arranged in the axial direction of the tunnel and arranged in multiple rows in the width direction of the tunnel and fixed integrally.

[0005] As a method for removing an existing ceiling part formed by a large number of ceiling slabs that are continuously arranged in the axial direction of the tunnel and fixed integrally in a state of being arranged in multiple rows in the width direction of the tunnel by joining the ends to the linear support steel bars installed at intervals in multiple rows, for example, a method of removing each existing ceiling slab 52 one by one by using an iron fork 51 attached to one or more backhoes 50 is conceivable (see FIGS. 8(a) and (b)).

[0006] However, in the method of removing each existing ceiling slab 52 one by one by using the iron fork 51 attached to the backhoe 50, a lot of time is required for the removal work. Also, if multiple backhoes 50 are used to shorten the time, the working ranges by the iron forks 51 will interfere with each other, making it difficult to work efficiently. Further, if a large number of existing ceiling slabs 52 made of precast concrete are preferably made of ALC (lightweight cellular concrete building materials) panels, there is a possibility that they will crack when gripped by the iron fork 51 or the linear support steel bars will bend, so careful work that takes time is required.

[0007] In addition, the work of removing the ceiling portion formed by the above-mentioned numerous existing ceiling plates 52 needs to be carried out with the tunnel closed to traffic. Especially when the tunnel is a multi-lane road tunnel that constitutes a trunk road, etc., the time of repeated traffic stoppage should preferably be as short as about several hours, and after the completion of the work within a predetermined time, it is necessary to be able to surely lift the traffic stoppage. However, in the method of removing each existing ceiling plate 52 with difficulty using the iron fork 51 attached to the backhoe 50, the work is likely to be delayed and there will be uncertainty in lifting the traffic stoppage in a short time, so it is difficult to adopt.

[0008] For these reasons, there is a demand for the development of a technology that can easily and surely remove the ceiling portion formed by a large number of existing ceiling plates that are continuously arranged in the axial direction of the tunnel and fixed integrally in a state of being arranged in multiple rows in the width direction of the tunnel by joining the ends to the linear support steel materials installed at intervals in multiple rows within a predetermined time.

[0009] An object of the present invention is to provide a method for removing a tunnel ceiling portion that enables the ceiling portion formed by a large number of existing ceiling plates, which are continuously arranged in the axial direction of the tunnel and fixed integrally in a state of being arranged in multiple rows in the width direction of the tunnel by joining the ends to the linear support steel materials installed at intervals in multiple rows, to be easily and surely removed by the work within a predetermined time.

Means for Solving the Problems

[0010] The present invention relates to a method for removing a tunnel ceiling portion, in which linear support steel materials are supported on the upper part of a tunnel lining body, extend parallel to the axial direction of the tunnel, are installed in multiple rows at intervals, and are joined at their ends, so as to be continuously arranged in the axial direction of the tunnel and arranged and fixed in multiple rows in the width direction of the tunnel, thereby integrally forming a plurality of rectangular existing ceiling plates that form the ceiling portion of the tunnel and enabling them to be removed by an operation within a predetermined time. In a predetermined construction area in the axial direction of the tunnel, an operation of removing some of the existing ceiling plates and installing replacement pieces that are lighter than the existing ceiling plates in place of the removed existing ceiling plates is carried out as an operation within a predetermined time when the use of the tunnel is restricted, and this operation is repeatedly carried out until all the existing ceiling plates in the predetermined construction area are replaced with the replacement pieces. This is a ceiling plate replacement step. And a replacement piece removal step of carrying out an operation of removing all the replacement pieces replaced in the ceiling plate replacement step as an operation within a predetermined time when the use of the tunnel is interrupted. By providing a method for removing a tunnel ceiling portion configured to include these steps, the above object is achieved.

[0011] And in the method for removing a tunnel ceiling portion of the present invention, in the ceiling plate replacement step, preferably, for each one or two or more rows in multiple rows, the operation of installing the replacement pieces in place of the existing ceiling plates is repeatedly carried out, so that all the existing ceiling plates in the predetermined construction area are replaced with the replacement pieces.

[0012] Also, in the method for removing a tunnel ceiling portion of the present invention, in the replacement piece removal step, preferably, the predetermined construction area is partitioned into a plurality of construction spans in the axial direction of the tunnel, and for each construction span, the operation of removing the replacement pieces is repeatedly carried out, so that all the replacement pieces are removed.

[0013] Furthermore, in the method for removing a tunnel ceiling portion of the present invention, preferably, the linear support steel materials include those supported in a state of being suspended from the upper part of the tunnel lining body.

[0014] Furthermore, in the method for removing the tunnel ceiling part of the present invention, the replacement piece is made of a metal plate having a rectangular planar shape with a long side portion having a length corresponding to the interval width of the linear support steel materials installed in a plurality of rows, and the end portions in the long side direction are detachably joined to the linear support steel materials by bolt joining, so that they are arranged and fixed in series in the short side direction. This is preferable.

[0015] Also, in the method for removing the tunnel ceiling part of the present invention, the replacement piece preferably has a U-shaped cross-sectional shape with an opening surface on the upper surface side, with reinforcing ribs standing along the long side portions on both sides of the metal plate.

[0016] Furthermore, in the method for removing the tunnel ceiling part of the present invention, it is preferable that a plurality of the replacement pieces arranged in series in the short side direction are formed such that an integer multiple of the length of the short side portion of the metal plate corresponds to the length corresponding to the construction span, and they are formed to have the same planar shape.

Advantages of the Invention

[0017] According to the method for removing the tunnel ceiling part of the present invention, by joining the end portions to the linear support steel materials installed at intervals in a plurality of rows, it is possible to easily and surely remove, by an operation within a predetermined time, the ceiling part formed by a large number of existing ceiling plates that are continuously arranged in the axial direction of the tunnel and arranged in a plurality of rows in the width direction of the tunnel and fixed integrally.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0019] The method for removing the tunnel ceiling portion according to a preferred embodiment of the present invention is a method adopted to efficiently and surely remove the ceiling portion 12 formed by a large number of existing ceiling plates 11 made of precast concrete, which are installed above a road tunnel 10 forming, for example, a three-lane arterial road, as shown in FIGS. 1(a) and 1(b), preferably during a predetermined time period when the lanes are restricted at night or within a limited predetermined time period of about several hours when all lanes are closed to traffic. That is, the existing ceiling portion 12 of the road tunnel 10, for example, may need to be removed due to aging or reconstruction of the tunnel. The method for removing the tunnel ceiling portion of the present embodiment is developed as a method for removing the ceiling portion 12 formed by such a large number of existing ceiling plates 11 while minimizing the impact on the vehicles traveling in the road tunnel 10.

[0020] In addition, in the present embodiment, the road tunnel 10 has a circular cross-sectional shape, and the inner wall surface is preferably covered with a tunnel lining 20 made of in-situ concrete or sprayed concrete, and a road structure 23 is constructed from the lower part to the side part to form, for example, a three-lane road.

[0021] Furthermore, in the present embodiment, above the road tunnel 10, an existing ceiling portion 12 formed by a large number of precast concrete existing ceiling plates 11 is provided so as to cover the tunnel lining 20 at the top end portion of the tunnel from below. The ceiling portion 12 is supported in a suspended state from the top end portion via a suspension member 21 such as a suspension steel bar at the upper part of the tunnel lining 20, or is supported from the side wall portion via a bracket 22. By joining both end portions to a linear support steel material 13 (see FIG. 5), it is continuously arranged in the axial direction X of the tunnel and arranged and fixed in multiple rows in the width direction Y of the tunnel, and is formed by a large number of existing ceiling plates 11 integrated in a state (see FIGS. 2(a) and 2(b)).

[0022] The method for removing the tunnel ceiling part of this embodiment is adopted as a method for easily and surely removing the ceiling part 12 composed of a large number of existing ceiling plates 11, which are continuously arranged in the axial direction X of the tunnel and fixed integrally in a state of being arranged in multiple rows in the width direction Y of the tunnel, by joining the ends to the linear support steel materials 13 installed at intervals in multiple rows within a limited predetermined time.

[0023] And the method for removing the tunnel ceiling part of this embodiment is such that the ends are joined to the linear support steel materials 13 supported on the upper part of the tunnel lining body 20, extending parallel to the axial direction X of the tunnel 20, and installed at intervals in multiple rows. By being continuously arranged in the axial direction X of the tunnel 10 and arranged and fixed in multiple rows in the width direction Y of the tunnel, a plurality of rectangular existing ceiling plates 11 (see FIGS. 1(a) and (b)) that integrally form the ceiling part 12 of the tunnel can be removed by an operation within a predetermined time. It is a method for removing the tunnel ceiling part, and in a predetermined construction area R in the axial direction X of the tunnel 10, as shown in FIGS. 2(a), (b) and FIGS. 3(a), (b), some of the existing ceiling plates 11 are removed, and a replacement piece 14 that is lighter than the existing ceiling plate 11 is installed in place of the removed existing ceiling plate 11. The operation is carried out as an operation within a predetermined time when the use of the tunnel 10 is restricted, and is repeated until all the existing ceiling plates 11 in the predetermined construction area R are replaced with the replacement pieces 14, which is the ceiling plate replacement process. As shown in FIGS. 4(a) and (b), the operation of removing all the replacement pieces 14 replaced in the ceiling plate replacement process is carried out as an operation within a predetermined time when the use of the tunnel 10 is interrupted, and it includes the replacement piece removal process. The replacement piece removal process is carried out, for example, within a limited predetermined time of about several hours when all lanes are closed at night, so as to remove the ceiling part 12 replaced from the existing ceiling plate 11 to the replacement piece 14 in the predetermined construction area R.

[0024] Moreover, in the ceiling panel replacement step of the method for removing the tunnel ceiling portion of the present embodiment, preferably, for each one or two or more columns in a plurality of columns, the operation of installing the replacement piece 14 by replacing it with the existing ceiling panel 11 is repeatedly performed (see FIGS. 2(a), (b) and FIGS. 3(a), (b)), so that all the existing ceiling panels 11 in the predetermined construction area R are replaced with the replacement pieces 14.

[0025] Furthermore, in the replacement piece removal step of the method for removing the tunnel ceiling portion of the present embodiment, preferably, the predetermined construction area R is partitioned into a plurality of construction spans S in the axial direction X of the tunnel, and for each construction span S, the operation of removing the replacement piece is repeatedly performed to remove all the replacement pieces (see FIGS. 4(a) to (c)).

[0026] Furthermore, in the present embodiment, four rows of the support steel materials 13 (see FIG. 5), excluding those arranged at both ends in the width direction Y of the tunnel 10, are arranged in a state of being suspended and supported from the top end portion of the upper part of the tunnel lining body 20 via the suspension members 21, and the support steel materials 13 arranged at both ends in the width direction Y are arranged in a state of being supported from the side wall portion of the upper part of the tunnel lining body 20 via the brackets 22 attached at a predetermined pitch in the axial direction X of the tunnel 10 (see FIG. 1(a)).

[0027] In this embodiment, the plurality of existing ceiling plates 11 forming the existing ceiling portion 12 of the tunnel 10 are preferably precast concrete plates made of lightweight aerated concrete (ALC). Each of them is formed to have a rectangular planar shape with a size of, for example, a short side length of about 600 mm and a long side length of about 2000 mm, has a thickness of about 100 mm, and has a weight of about 60 kg. As described above, each existing ceiling plate 11 is placed and joined at the ends on both sides in the long side direction on each pair of adjacent linear support steel materials 13 extending in parallel to the axial direction X of the tunnel 10 and installed in a plurality of rows (see FIG. 5). In a state where the short side portion is along the axial direction X of the tunnel 10, a plurality of them are arranged in series in the axial direction X of the tunnel 10 and are arranged side by side in, for example, five rows in the width direction Y of the tunnel (see FIG. 1(b)).

[0028] Also, in this embodiment, in each row in the width direction Y of the tunnel, at the joint portion between each pair of adjacent existing ceiling plates 11 among the plurality of existing ceiling plates 11 arranged in series in the axial direction X of the tunnel 10, a joint portion 11a is formed. As shown in FIG. 5, these joint portions 11a are preferably filled with joint mortar 11c and solidified with reinforcing round steel 11b appropriately embedded therein. As a result, the plurality of existing ceiling plates 11 arranged in series in the axial direction X of the tunnel 10 are integrally and firmly joined to each other. In this embodiment, the reinforcing round steel 11b is embedded, for example, at every other joint portion 11a in the joint portion 11a between each pair of adjacent existing ceiling plates 11 arranged in series in the axial direction X of the tunnel 10.

[0029] In addition, for each of the plurality of existing ceiling panels 11, both end portions on both sides in the long side direction thereof are firmly joined to a pair of adjacent linear support steel members 13 on both sides, for example, using end mortar 11d. As a result, the plurality of existing ceiling panels 11 in adjacent rows are firmly joined integrally also in the width direction Y of the tunnel 10 via the linear support steel members 13. By these, the plurality of existing ceiling panels 11 are joined and continuously provided in the axial direction X of the tunnel 10 and are also joined and continuously provided in the width direction Y of the tunnel, thereby forming the existing ceiling portion 12 of the tunnel 10 integrally.

[0030] In the present embodiment, the linear support steel member 13 to which the end portions in the long side direction of the plurality of existing ceiling panels 11 are joined respectively is formed using a steel plate having a thickness of about 5 to 6 mm, for example, and preferably has a T-shaped cross-sectional shape, and is a steel member linearly extending in the axial direction X of the tunnel 10. The linear support steel member 13 is formed by joining unit steel members 13a each having a length of about 2400 mm in the extending direction via joint hardware, thereby forming the linear support steel member 13 linearly extending in the axial direction X of the tunnel 10 with a desired length. In the present embodiment, the linear support steel members 13 are arranged at six positions with an interval width of about 2000 mm between centers in the width direction X of the tunnel 10. As described above, the two linear support steel members 13 arranged at both end portions in the width direction Y of the tunnel 10 are placed on brackets 22 attached to the upper side wall portions of the tunnel lining 20 and are provided in a state of being supported by the upper side wall portions of the tunnel lining 20, and the four linear support steel members 13 at the intermediate portions therebetween are suspended via suspension members 21 and are provided in a state of being supported from the top end portion at the upper part of the tunnel lining 20 (see Fig. 1(a)).

[0031] The hanging member 21 for hanging the four linear support steel members 13 at the middle part from the top end part of the tunnel lining body 20 is composed of, for example, a hanging wire or a hanging steel bar (in this embodiment, a hanging steel bar). The upper end of the hanging member 21 is connected to a known anchor member 24 (see Fig. 1(a)) fixed to the top end part of the tunnel lining body 20, and the lower end is connected to the upper end of the linear support steel member 13 via a connecting fitting 25 (see Fig. 5), so that the linear support steel member 13 can be supported in a state of being hung from the top end part of the tunnel lining body 20. Further, a plurality of the hanging members 21 are attached at a predetermined pitch in the axial direction X of the tunnel 10 at each attachment position in the width direction Y of the tunnel 10, so that the four linear support steel members 13 at the middle part, together with the two linear support steel members 13 placed at both ends, can be extended parallel to each other in the axial direction X of the tunnel 20 and installed in a state of being arranged at the same height position in the vertical direction of the tunnel 20.

[0032] And in this embodiment, as described above, all of the plurality of rectangular existing ceiling boards 11 constituting the existing ceiling part 12 provided in the predetermined construction area R in the axial direction X of the tunnel 10 are to be replaced by replacement pieces 14 that are lighter than the existing ceiling boards 11 in the ceiling board replacement process described later (see Figs. 2(a), (b) to Figs. 4(a), (b)).

[0033] Here, the replacement piece 14 to replace the existing ceiling board 11 is, in this embodiment, as shown in FIGS. 6 and 7, a metal plate 14a having a rectangular planar shape with a thickness of about 4 mm, having a long side portion with a length slightly shorter than, for example, about 2000 mm, which corresponds to the interval width between the centers of the linear support steel materials 13 installed in a plurality of rows. Also, the replacement piece 14 has a short side portion with a length of preferably about 300 mm, which is 1 / 2 of the length of the short side portion of the existing ceiling board 11. In this embodiment, preferably, the replacement piece 14 has a U-shaped cross-sectional shape with the upper surface side being the opening surface, by having reinforcing ribs 14b erected along the long side portions on both sides of the metal plate 14a. Since the replacement piece 14 has a U-shaped cross-sectional shape, the rigidity of the replacement piece 14 is increased, and when it is replaced with the existing ceiling board 11 and attached to the ceiling portion 12, the ceiling portion 12 of the tunnel 10 can be maintained in a more stable structure even after replacement.

[0034] Further, the replacement piece 14 is lighter than the existing ceiling board 11 having a weight of about 60 kg, preferably having a weight of 1 / 2 or less of this, for example, about 25 kg. As a result, it can be easily handled by the manual work of the operator. Bolt fastening holes 14c are formed at both ends in the long side direction of the metal plate 14a (see FIG. 6). As shown in FIG. 7, by aligning these bolt fastening holes 14c with the bolt insertion holes formed in the flange portion 13b of the linear support steel material 13 and fastening the bolt member 14d, the end portion in the long side direction of the replacement piece 14 can be detachably joined to the linear support steel material 13 by bolt joining. Also, as a result, each replacement piece 14 can be smoothly fixed in a removable state at a predetermined position to replace the existing ceiling board 11, and these replacement pieces 14 can be continuously arranged in the short side direction without gaps. These fixed replacement pieces 14 can be easily and smoothly removed from the linear support steel material 13 by releasing the fastening of the bolt member 14d.

[0035] Furthermore, since the replacement piece 14 has a short side portion with a length that is half the length of the short side portion of the existing ceiling panel 11, two replacement pieces 14 can be replaced for each single existing ceiling panel 11 (see FIGS. 2(b) and 3(b)). In addition, in this embodiment, a plurality of replacement pieces 14 arranged in series in the short side direction along the axial direction X of the tunnel 10 are preferably formed such that an integral multiple (24 times in this embodiment) of the length of the short side portion of the metal plate 14a corresponds to a predetermined construction span S (see FIG. 3(b)), and are formed to have a planar shape of the same size.

[0036] Moreover, the method for removing the tunnel ceiling portion of this embodiment is a method that enables the removal of a plurality of rectangular existing ceiling panels 11 that are arranged in series in the axial direction X of the tunnel 10 and arranged and fixed in a plurality of rows in the width direction Y of the tunnel to integrally form the existing ceiling portion 12 of the tunnel 10 by means of work within a predetermined time. As described above, it includes a ceiling panel replacement step and a replacement piece removal step. The ceiling panel replacement step is, as work within a predetermined time when the use of the tunnel is restricted, for example, work during a predetermined time period when the lanes are restricted at night. Preferably, for each one or two or more rows in a plurality of rows, it is repeated on different days (see FIGS. 2(a), (b) and 3(a), (b)) so as to replace all the existing ceiling panels 11 in a predetermined construction area R with replacement pieces 14. In the replacement piece removal step, as work within a predetermined time when the use of the tunnel 10 is interrupted, for example, work within a preferably limited predetermined time of about 4 hours in the middle of the night when it is possible to stop all lanes from passing at night is repeated on different days for each predetermined construction span S to remove all of the existing ceiling portion 12 in the predetermined construction area R (see FIGS. 4(a) to (c)).

[0037] In this embodiment, the ceiling panel replacement process, for example as the first step, as shown in FIGS. 2(a) and 2(b), in a predetermined construction area R in the axial direction X of the tunnel 10, removes two rows of existing ceiling panels 11 in one region 10a in the width direction Y of the tunnel 10, and replaces these two rows of removed existing ceiling panels 11 with lightweight replacement pieces 14 and arranges and fixes them. Such work is preferably carried out in the time period from night to morning when the traffic volume of vehicles is small. For example, two lanes on one side out of three lanes are regulated as the work area, and vehicles can pass through the remaining one lane while the work is being carried out.

[0038] That is, in the first step of the ceiling panel replacement process, for example, in the work area of two lanes on one side, using the upper part of the existing ceiling part 12 as the work space, while a worker enters this work space and chisels off the end mortar 11d and the joint mortar 11c by hand, the two rows of existing ceiling panels 11 that are integrally connected are disassembled into individual existing ceiling panels 11, and the disassembled individual existing ceiling panels 11 can be carried out of the work space and removed, for example, by the manual work of the worker or the work using simple equipment. Also, two replacement pieces 14 are arranged to replace each of all the removed existing ceiling panels 11, and are easily fixed to the positions of the removed existing ceiling panels 11, for example, by the manual work of the worker, by detachable bolt joints, and can be installed removably and smoothly.

[0039] The first step of such a ceiling panel replacement process is to regulate two lanes on one side as the work area until all of these two rows of existing ceiling panels 11 in the predetermined construction area R are replaced with replacement pieces 14, and keep the remaining one lane drivable. The work in the time period from night to morning can be repeated over one day or multiple days. After replacing all of the two rows of existing ceiling panels 11 in the predetermined construction area R and installing the replacement pieces 14, next, the second step of the ceiling panel replacement process can be carried out.

[0040] In the second step of the ceiling panel replacement process, as shown in FIGS. 3(a) and 3(b), in a predetermined construction area R in the axial direction X of the tunnel 10, three rows of existing ceiling panels 11 in the other area 10b in the width direction Y of the tunnel 10 are removed, and these three rows of removed existing ceiling panels 11 are replaced with lightweight replacement pieces 14 and arranged and fixed. Similar to the first step, such work is preferably carried out in the time period from night to morning when the traffic volume of vehicles is small. For example, two lanes on one side of the other side of the three lanes are regulated as the work area, and vehicles can pass through the remaining one lane while the work is being carried out.

[0041] That is, in the second step of the ceiling panel replacement process, for example, in the work area of two lanes on one side of the other side, similar to the first step, the upper part of the existing ceiling part 12 is used as the work space. By the manual work of the workers who enter this work space, while chipping off the end mortar 11d and the joint mortar 11c, the one row of existing ceiling panels 11 that are continuously provided integrally are disassembled into individual existing ceiling panels 11, and the disassembled individual existing ceiling panels 11 can be carried out of the work space and removed by, for example, manual work of the workers or work using simple equipment. Also, two replacement pieces 14 are arranged to replace each of the removed existing ceiling panels 11, and can be easily fixed by detachable bolt joints at the positions of the removed existing ceiling panels 11 by, for example, manual work of the workers, and installed removably and smoothly.

[0042] Similar to the first step, the second step of such a ceiling panel replacement process is carried out by repeating the work in the time period from night to morning, with two lanes on one side of the other side regulated as the work area and the remaining one lane being drivable, until all of these three rows of existing ceiling panels 11 in the predetermined construction area R are replaced with replacement pieces 14. After all three rows of existing ceiling panels 11 in the predetermined construction area R are replaced and the replacement pieces 14 are installed, next, the replacement piece removal process is carried out.

[0043] As shown in FIGS. 4(a) to 4(c), the replacement piece removal process is a process of removing all of the five rows of replacement pieces 14 that were replaced with the existing ceiling board 11 in the first and second steps of the above-described ceiling board replacement process. Since the replacement piece removal process needs to be carried out with all lanes of the road tunnel 10 closed to traffic, it is preferably carried out during a late-night time period when the traffic volume of vehicles is small. Within a limited predetermined time of about 4 hours with all lanes closed to traffic, for example, for each predetermined construction span S of about 7.2 m, the work is repeated on a plurality of different days (in this embodiment, three different days) to remove the entire ceiling portion 12 replaced by the replacement pieces 14 in the predetermined construction area R.

[0044] In the replacement piece removal process, in the work within a limited time of about 4 hours with all lanes closed to traffic each day, for each predetermined construction span S, preferably a known tunnel inspection vehicle (not shown) equipped with a work deck and lifting equipment is used, and for example, by means of work using workers and simple equipment, all five rows of replacement pieces 14 that were replaced with the existing ceiling board 11 are efficiently and quickly removed.

[0045] That is, in the replacement piece removal process of this embodiment, each of the replaced replacement pieces 14 is lightweight, with a weight of about 25 kg, and can be easily handled by manual work of workers. In addition, they are removably fixed to the linear support steel material 13 on which their ends are placed by detachable bolt joints using bolt members 14d. Therefore, by releasing the tightened state of the bolt members 14d, each of these replacement pieces 14 can be smoothly removed one by one and quickly removed. Also, the remaining linear support steel material 13 and the suspension members 21 can also be easily and smoothly removed by being appropriately cut during work by workers and simple equipment on the work deck of the work space and the tunnel inspection vehicle. Also, the existing ceiling board 11 removed in each predetermined construction span S can be loaded onto a unique vehicle and carried out, for example.

[0046] In this way, in the replacement piece removal process of the present embodiment, in each predetermined construction span S, the lightweight replacement pieces 14 arranged in the ceiling portion 12 in place of the existing ceiling boards 11 can be easily and smoothly removed preferably one by one by the work of workers or simple equipment. Therefore, preferably during the late-night hours when the traffic volume of vehicles is small, the removal work can be carried out speedily and surely completed within a limited predetermined time of about 4 hours with all lanes closed to traffic.

[0047] Therefore, according to the method for removing the tunnel ceiling portion of the present embodiment, by the ceiling board replacement process and the replacement piece removal process, by joining the ends to the linear support steel materials 13 installed at intervals in a plurality of rows, the existing ceiling portion 12 composed of a large number of existing ceiling boards 11 that are continuously arranged in the axial direction X of the tunnel 10 and fixed integrally in a state of being arranged in a plurality of rows in the width direction Y of the tunnel 10 can be easily and surely removed by the work within a predetermined time.

[0048] Also, according to the method for removing the tunnel ceiling portion of the present embodiment, in the ceiling board replacement process, after the replacement pieces 14 are installed in the ceiling portion 12 where the existing ceiling boards 11 have been removed, replacing these removed existing ceiling boards 11, the lane regulation is released and the work is terminated. As a result, in each construction span S, until all the replacement pieces 14 in the entire area are removed in the replacement piece removal process, the ceiling portion 12 of the tunnel 10 can be kept in a stable structure, and for example, it is possible to effectively avoid the occurrence of sway or the like in the ceiling portion 12 where some of the existing ceiling boards 11 have been removed due to vibrations or wind pressure during vehicle travel, resulting in an unstable state of the ceiling portion 12.

[0049] Furthermore, in the present embodiment, the plurality of replacement pieces 14 arranged in series in the short side direction along the axial direction X of the tunnel 10 are formed such that an integral multiple of the length of the short side portion of the metal plate 14a corresponds to a predetermined construction span S, and are formed to have a planar shape of the same size. Therefore, when the construction takes several days, the ends of the existing ceiling boards 11 remaining on the ceiling portion 12 can be aligned with the ends of the replaced replacement pieces 14, thereby enabling the ceiling portion 12 to be maintained with a stable structure.

[0050] Note that the present invention is not limited to the above-described embodiment and various modifications are possible. For example, in the ceiling removal step, it is not always necessary to remove the replaced replacement pieces one by one, and a plurality of pieces may be removed simultaneously. The replacement piece does not necessarily have to have reinforcing ribs standing along the long side portions on both sides of the metal plate, and it may be composed of only the metal plate. The ceiling portion formed by a plurality of precast concrete existing ceiling boards removed by the method for removing a tunnel ceiling portion of the present invention does not necessarily have to be the ceiling portion installed above the road tunnel. The ceiling portion removed by the method for removing a tunnel ceiling portion of the present invention, which is formed by a plurality of existing ceiling boards whose ends are joined to linear support steel materials arranged in series in the axial direction of the tunnel and arranged and fixed in a plurality of rows in the width direction of the tunnel, may be, for example, the ceiling portion of the station building portion of a railway tunnel.

[0051] 10 Tunnel (road tunnel) 10a One region 10b The other region 11 Existing ceiling board 11a Joint portion 11b Joint mortar 11c Reinforcing round steel 11d End mortar 12 Ceiling portion 13 Linear support steel material 13a Unit steel material 14 Replacement piece 14a Metal plate 14b Reinforcing rib 14c Bolt fastening hole 14d Bolt member 20-ton tunnel lining 21 Suspension member 22 Bracket 23 Road structure 24 Anchor member 25 Connecting hardware Axial direction of X tunnel Width direction of Y tunnel R Predetermined construction area S Predetermined construction span

Claims

1. A method for removing a tunnel ceiling section, wherein linear support steel materials are supported on the upper part of a tunnel lining structure, extend parallel to the axial direction of the tunnel, are installed in multiple rows at intervals, and are joined at their ends, so that they are continuously arranged in the axial direction of the tunnel and arranged and fixed in multiple rows in the width direction of the tunnel, thereby integrally forming the ceiling section of the tunnel. By means of work within a predetermined time, a plurality of rectangular existing ceiling plates can be removed, and the method is characterized in that: In a predetermined construction area in the axial direction of the tunnel, an operation of removing some of the existing ceiling plates and installing a replacement piece that is lighter than the existing ceiling plate in place of the removed existing ceiling plate is carried out as work within a predetermined time when the use of the tunnel is restricted. An existing ceiling plate replacement step of repeatedly performing the operation until all the existing ceiling plates in the predetermined construction area are replaced with the replacement pieces, and an operation of removing all the replacement pieces replaced in the existing ceiling plate replacement step is carried out as work within a predetermined time when the use of the tunnel is interrupted. The method for removing a tunnel ceiling section comprises a replacement piece removal step.

2. In the existing ceiling plate replacement step, the operation of installing the replacement piece in place of the existing ceiling plate is repeatedly carried out for each one or two or more rows in the multiple rows, so that all the existing ceiling plates in the predetermined construction area are replaced with the replacement pieces. The method for removing a tunnel ceiling section according to Claim 1.

3. In the replacement piece removal step, the predetermined construction area is divided into a plurality of construction spans in the axial direction of the tunnel, and for each construction span, the operation of removing the replacement piece is repeatedly carried out, so that all the replacement pieces are removed. The method for removing a tunnel ceiling section according to Claim 1 or 2.

4. The linear support steel material includes those supported in a state of being suspended from the upper part of the tunnel lining structure. The method for removing a tunnel ceiling section according to any one of Claims 1 to 3.

5. The replacement piece is made of a metal plate having a rectangular planar shape with a long side portion having a length corresponding to the interval width of the linear support steel materials installed in a plurality of rows. The end portion in the long side direction is detachably joined to the linear support steel material by bolt joining, so that the replacement pieces are arranged and fixed in series in the short side direction. The method for removing a tunnel ceiling portion according to any one of claims 1 to 4.

6. The replacement piece according to claim 5 has a U-shaped cross-sectional shape with an open surface on the upper surface side, with reinforcing ribs standing along the long side portions on both sides of the metal plate. The method for removing a tunnel ceiling portion.

7. A plurality of the replacement pieces arranged in series in the short side direction are formed such that an integral multiple of the length of the short side portion of the metal plate corresponds to the length corresponding to the construction span, and are formed to have a planar shape of the same size. The method for removing a tunnel ceiling portion according to claim 4 or 5.

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