Underground space construction methods
Patent Information
- Application Number
- JP2025031882
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-09-09
Smart Images
Figure 2026144534000001_ABST
Abstract
Description
[[TECHNICAL FIELD]]
[0001] The present invention relates to an underground space construction method. [[BACKGROUND ART]]
[0002] As a conventional underground space construction method, the one disclosed in the following Patent Document 1 is known. In this method, a pair of opposing retaining walls are constructed in the ground, the ground between them is excavated, and supports such as struts and retaining anchors are sequentially installed. After the completion of ground excavation, a box structure is constructed in the excavation space while supports are removed sequentially starting from the lower ones. [[PRIOR ART DOCUMENT]] [[PATENT DOCUMENT]]
[0003] [[Patent Document 1]] Japanese Patent No. 6543117 [[SUMMARY OF THE INVENTION]] [[PROBLEM TO BE SOLVED BY THE INVENTION]]
[0004] When this type of excavation method is applied, for example, under the road of an existing operating railway line, it is necessary to temporarily remove a part of the existing operating railway line for carrying in support materials and discharging excavated soil generated by excavation. For this reason, excavation work while continuing the operation of the line becomes difficult, and for example, workers are forced to carry out work at night when the operation is suspended. In view of such problems, an object of the present invention is to provide an underground space construction method capable of performing construction under the road of an existing operating railway line while the operation of the existing operating line is continued. [[MEANS FOR SOLVING THE PROBLEM]]
[0005] The gist of the present invention resides in the following [1] to [5].[+
[0006] [1] A method for constructing an underground space extending in the longitudinal direction of an existing operational railway line beneath the existing operational railway line, comprising: a temporary support step of constructing a temporary support structure below the existing operational railway line to temporarily support the existing operational railway line; a horizontal tunnel excavation step of excavating a horizontal tunnel extending from the side of the existing operational railway line so as to go under the existing operational railway line; an under-road excavation step of excavating below the existing operational railway line by digging from the horizontal tunnel in the longitudinal direction; and a support structure construction step of constructing a support structure in the excavated space excavated in the under-road excavation step, wherein in the under-road excavation step, the excavated soil generated by the excavation is discharged to the surface from the side of the existing operational railway line via the horizontal tunnel, and in the support structure construction step, support structure materials constituting the support structure are transported from the side of the existing operational railway line via the horizontal tunnel into the excavated space.
[0007] [2] The underground space construction method according to [1], wherein in the support structure construction process, the support structure materials are loaded onto the cargo bed of a designated material transport vehicle and transported through the excavation space from the horizontal tunnel to the planned location for the support structure, the material transport vehicle has a driver's cab and a cargo bed arranged side by side in the width direction of the vehicle, the cargo bed is open to the front and rear, and travels on the uneven ground surface of the excavation space.
[0008] [3] The underground space construction method according to [2], wherein in the shoring construction process, the shoring materials, which are longer than the length of the material transport vehicle, are loaded onto the material transport vehicle such that they protrude forward and backward from the loading platform in the direction of the vehicle length.
[0009] [4] The underground space construction method according to any one of [1] to [3], wherein in the support structure construction process, the support structure materials are loaded onto the cargo bed of a designated material transport vehicle and transported through the excavation space from the horizontal tunnel to the planned location for the support structure installation, and in the area of the excavation space through which the material transport vehicle passes, there are elevated sections located at both ends in the width direction of the existing operational line and a central bottom surface in the center in the width direction that is lower than the elevated sections, the bracing for the support structure is not yet installed, and the material transport vehicle travels on the central bottom surface.
[0010] [5] A method for constructing an underground space according to any one of [1] to [4], further comprising an underground structure construction step of constructing the underground structure in the excavated space. [Effects of the Invention]
[0011] According to the present invention, it is possible to provide an underground space construction method that allows construction work to be carried out beneath an existing railway line while the existing railway line continues to operate. [Brief explanation of the drawing]
[0012] [Figure 1] (a) is a plan view of the construction area of this embodiment, including the railway tracks, and (b) is a cross-sectional view taken along the line Ib-Ib. [Figure 2] (a) is a plan view of the section to be worked on during the tunnel excavation process, and (b) is a cross-sectional view of the same section taken along the line IIb-IIb. [Figure 3] (a) is a plan view of the section to be worked on during the road excavation process, and (b) is a cross-sectional view of the same section at IIIb-IIIb. [Figure 4] (a) and (b) are cross-sectional views of the construction area showing the construction process of the scaffolding in sequence. [Figure 5] (a) is a cross-sectional view of the completed underground space beneath the railway tracks, and (b) is a cross-sectional view of the underground space during the underground structure construction process. [Figure 6] (a) and (b) are cross-sectional views of the underground space during the underground structure construction process following Figure 5(b). [Figure 7] (a) is a perspective view of the material transport vehicle seen from the front right of the vehicle, and (b) is a perspective view of the material transport vehicle 31 seen from the front left of the vehicle. [Modes for carrying out the invention]
[0013] Hereinafter, an embodiment of the underground space construction method according to the present invention will be described in detail with reference to the drawings. The underground space construction method of this embodiment is used in railway construction. This railway construction aims to underground an existing railway that is in operation, and is carried out while railway operations continue, and involves relocating the tracks directly beneath their current location. According to the underground space construction method of this embodiment, the ground directly beneath the tracks in the construction area is excavated, and an underground structure, which is the destination for the relocated tracks, is constructed directly beneath the tracks.
[0014] The underground space construction method of this embodiment comprises the following steps: earth retaining wall construction step, temporary support step, horizontal tunnel excavation step, roadside excavation step, shoring construction step, and underground structure construction step.
[0015] [Construction process for retaining walls] Figure 1(a) is a plan view of the construction section 100 of this embodiment, including the existing operational railway line 1, and Figure 1(b) is a cross-sectional view taken along line Ib-Ib. As shown in Figure 1, in the retaining wall construction process, retaining walls 11, 11 are cast into the ground on both sides of the railway line 1 and temporary support structure 3 in the direction of the railway line width. In addition, in a part of the construction section 100, a U-shaped retaining wall 13 surrounding the horizontal tunnel 17 (Figure 2), which will be described later, is cast so as to be continuous with one of the retaining walls 11. The retaining wall 13 protrudes outward from the retaining wall 11 in the direction of the railway line width. The length of the construction section 100 is, for example, approximately 180m.
[0016] [Temporary receiving process] In the temporary supporting step, a temporary supporting structure 3 is constructed below the track 1 in the construction target section 100, and the track 1 is temporarily supported. Specifically, in the region between the retaining walls 11, 11, temporary support piles 5 are driven into the ground on both sides of the track 1 with the track 1 sandwiched in the track width direction. Thereafter, after the ground below the track 1 is excavated to a required depth in the region including the temporary support piles 5, a construction girder 7 and a needle beam 9 are inserted below the track 1. The construction girder 7 extends in the longitudinal direction of the track and temporarily supports the track 1, and the needle beam 9 extends in the width direction of the track and supports the construction girder 7. The needle beam 9 is supported at both ends by a pair of left and right temporary support piles 5, 5. As a result, the temporary supporting structure 3 consisting of the pair of left and right temporary support piles 5, 5, the needle beam 9, and the construction girder 7 is constructed, and the track 1 is temporarily supported. A plurality of such temporary supporting structures 3 are constructed at predetermined intervals in the longitudinal direction of the track over the entire construction target section 100.
[0017] [Adit Excavation Step] FIG. 2(a) is a plan view of the construction target section 100 in the adit excavation step, and (b) is a cross-sectional view taken along line IIb-IIb thereof. As shown in FIG. 2(a) and FIG. 2(b), an adit 17 is constructed in the adit excavation step. Specifically, a region surrounded by the retaining wall 13 on the side of the track 1 is excavated from the ground by a small backhoe 19, and further excavated in the track width direction so as to go under the track 1, whereby the adit 17 is excavated. That is, the completed adit 17 extends in the track width direction at any position in the construction target section 100 so as to go under the track 1 from the side of the track 1. The vertical distance between the bottom surface of the adit 17 and the needle beam 9 is, for example, about 2 m. Hereinafter, a portion of the adit 17 located on the side of the track 1 and opened upward is referred to as an adit opening 17a.
[0018] [Under-track Excavation Step] Fig. 3(a) is a plan view of the construction target section 100 in the under-road excavation process, and (b) is a sectional view taken along line IIIb-IIIb thereof. As shown in Fig. 3(a) and Fig. 3(b), in the under-road excavation process, a region between the retaining walls 11, 11 below the track 1 is excavated. Specifically, excavation is carried out forward from the horizontal adit 17 in the longitudinal direction of the track by a small backhoe 19, and the region between the retaining walls 11, 11 directly below the track 1 is excavated over the entire length of the construction target section 100. Here, the central portion in the track width direction is excavated deeper than both end portions into a trapezoidal shape. Then, at the bottom of the excavation space 21 formed by excavation, there exist high step portions 23a which are relatively high portions at both ends in the track width direction, and a central bottom surface 23b excavated lower than the high step portions 23a at the center in the track width direction.
[0019] In the excavation space 21 of this type, the portions at both ends contacting the retaining walls 11, 11 remain at a relatively high position as the high step portions 23a, so even in the stage before the struts 27b (see Fig. 4(b)) are installed, the retaining walls 11, 11 can be supported by the ground of the high step portions 23a. On the other hand, since the central portion is excavated deep to the central bottom surface 23b, headroom for the movement and operation of the small backhoe 19 and other heavy machinery is secured. The space above the central bottom surface 23b also functions as a movement path for heavy machinery. Excavation of this type is sometimes referred to as "island-shaped excavation".
[0020] The central bottom surface 23b is formed to have the same depth so as to be continuous with the bottom surface of the horizontal adit 17 (see Fig. 2). The width of the excavation space 21 in the track width direction (the spacing between the retaining walls 11, 11) is, for example, about 10 m, and among this, the width of the central bottom surface 23b is, for example, about 5 m. Further, the vertical interval between the upper surface of the high step portion 23a and the hairpin girder 9 is, for example, about 1 m, and the vertical interval between the central bottom surface 23b and the hairpin girder 9 is, for example, about 2 m.
[0021] In this under-road excavation process, the excavated soil generated by the excavation beneath the railway track 1 is transported to the side tunnel 17 by a small dump truck (not shown) traveling along the central bottom surface 23b. The excavated soil transported and accumulated at the side tunnel opening 17a by the small dump truck is scooped up from the ground beside the railway track 1 by a backhoe (not shown) and discharged onto the surface, where it is loaded onto a dump truck (not shown).
[0022] [Shoring construction process] Figures 4(a) and 4(b) are cross-sectional views of the construction area 100, showing the construction process of the support structure in sequence. Next, in the support structure construction process, the support structure 27 is constructed in the excavated space 21 excavated in the underpass excavation process. Here, a material transport vehicle 31 and a small crane 33 are introduced into the excavated space 21 from the side of the railway track 1 via the side tunnel 17, for example, by being lowered from the ground into the tunnel opening 17a by another crane. The material transport vehicle 31 transports the support structure materials 29 that constitute the support structure 27 within the excavated space 21, and the small crane 33 performs the installation work of the support structure materials 29 within the excavated space 21.
[0023] The above-mentioned shoring materials 29 include H-rope and other materials that constitute the waling 27a and bracing 27b of the shoring 27. In the shoring construction process, first, the shoring materials 29 are transported from the side of the railway track 1 through the horizontal tunnel 17 (see Figure 2) into the excavation space 21. Specifically, the shoring materials 29 are lowered from the ground by a crane (not shown) onto the loading platform 57 of a material transport vehicle 31 waiting at the horizontal tunnel opening 17a (see Figure 2). Then, as shown in Figure 4(a), the material transport vehicle 31 travels from the horizontal tunnel 17 along the central bottom surface 23b of the excavation space 21 to transport the shoring materials 29 to the planned installation site. At the planned installation site, as shown in Figure 4(b), the shoring materials 29 are lifted by a small crane 33 and installed in the designated location, thereby constructing the shoring 27, which consists of waling 27a and bracing 27b.
[0024] The construction of the scaffolding 27 as described above is carried out sequentially from locations farther from the horizontal tunnel 17 to those closer to it, so that the scaffolding 27 is constructed over the entire construction area 100. According to this construction order of the scaffolding 27, the material transport vehicle 31 transports the scaffolding materials 29 to the planned installation location by passing through the area closer to the horizontal tunnel 17 than the planned installation location. In other words, the material transport vehicle 31 loaded with scaffolding materials 29 passes through the area where the bracing 27b of the scaffolding 27 has not yet been installed. The material transport vehicle 31 does not need to enter the area further back where the bracing 27b, which has stricter headroom restrictions, has already been installed. Similarly, the small crane 33 does not need to enter the area further back where the bracing 27b, which has even stricter headroom restrictions, has already been installed.
[0025] In the underground space construction method of this embodiment, the above-described road excavation process and the support structure construction process are repeated alternately. With each repetition of the road excavation process and the support structure construction process, the number of bracing beams 27b in the support structure 27 increases by one, and the excavated space 21 deepens by the pitch of the bracing beams 27b (for example, about 2m). At the same time, the excavation and support structure construction are repeated in the horizontal tunnel 17 as well, and the horizontal tunnel 17 also deepens in the same way. In the underground space 37 beneath the railway track 1 that is finally completed, there is a support structure 27 including multiple levels (three levels in the example shown in the figure) of bracing beams 27b, as shown in Figure 5(a), and the underground space 37 has sufficient depth for the construction of the underground structure. The floor surface of the underground space 37 is formed flat, not island-shaped.
[0026] [Underground framework construction process] After the underground space 37 is completed, the underground structure 41 (see Figure 6(b)) is constructed in this underground space 37. Specifically, first, as shown in Figure 5(b), the base slab 41a of the underground structure 41 is constructed of reinforced concrete on the floor surface of the underground space 37, extending across the entire width of the track. Next, as shown in Figure 6(a), the lowest bracing 27b and waling 27a of the support structure 27 are removed (support structure removal process). After that, side walls 41b are constructed of reinforced concrete, rising to a predetermined height at both ends of the base slab 41a in the width of the track (side wall construction process). Then, as shown in Figure 6(b), the lowest bracing 27b and waling 27a of the remaining support structure 27 are removed (support structure removal process), and the side walls 41b are extended upwards by construction of reinforced concrete (side wall construction process). As described above, the process of removing the shoring and constructing the side walls is repeated alternately, so that the side walls 41b reach the required height throughout the entire construction section 100, all the shoring 27 is removed, and the underground structure 41 is completed.
[0027] In the above-described shoring removal process, the removed shoring materials 29 are transported within the underground space 37 to the tunnel opening 17a (see Figure 2) of the tunnel 17, and then lifted up to the surface by a crane (not shown) from the ground beside the railway track 1. Since the base slab 41a already exists at the stage when the shoring removal process is carried out, there is no need to transport the shoring materials 29 over uneven ground; they can be transported on the leveled base slab 41a. Therefore, there is little need to use the material transport vehicle 31, and another type of transport trolley or the like can be used. That is, for example, it is sufficient to use an unpowered flatbed trolley (not shown) that can travel on the leveled base slab 41a, and the shoring materials 29 can be loaded onto the flatbed trolley and transported by hand from the installation site to the tunnel 17.
[0028] Next, we will describe the material transport vehicle 31 used in the aforementioned shoring construction process. As shown in Figure 4(a), the material transport vehicle 31 is a vehicle that, in the shoring construction process, loads the shoring materials 29 with their longitudinal direction facing the longitudinal direction of the railway track and travels along the longitudinal direction of the railway track on the central bottom surface 23b. In the first shoring construction process, the material transport vehicle 31 travels through the area of the excavation space 21 under the railway track 1 where the bracing 27b has not been installed. This area cannot be excavated to a very deep depth so that the retaining walls 11, 11 can be supported by the elevated sections 23a, 23a and the central bottom surface 23b, even if the bracing 27b has not been installed. Therefore, the height from the central bottom surface 23b to the pier girder 9 cannot be made very high. The material transport vehicle 31, including the shoring materials 29 loaded on it, must fit within the height range from the central bottom surface 23b to the pier beam 9 under the conditions described above.
[0029] Figure 7(a) is a perspective view of the material transport vehicle 31 as seen from the front right of the vehicle, and Figure 7(b) is a perspective view of the material transport vehicle 31 as seen from the front left of the vehicle. The material transport vehicle 31 comprises a body 51 and crawlers 53 provided on the underside of the body 51. As the material transport vehicle 31 employs a crawler system, it can travel on the central bottom surface 23b of the excavation space 21, which is in an uneven state, and there is no need to lay rails, steel plates, etc. on the central bottom surface 23b for transporting support materials 29. Note that tires may be used instead of crawlers 53 as long as they can travel on the central bottom surface 23b, which is in an uneven state.
[0030] Furthermore, the material transport vehicle 31 is equipped with a driver's seat 55 located at the front right end of the vehicle body 51, a flat cargo bed 57 located on the left side of the vehicle body 51 that extends approximately the entire length of the vehicle body 51, and a vertical partition fence 59 that separates the cargo bed 57 from the driver's seat 55 side in the left-right direction. The material transport vehicle 31 is approximately 3m long and 1.9m wide. The cargo bed 57 is approximately 3m long and 1.1m wide, and its height from the ground is approximately 0.7m. The maximum load capacity of the material transport vehicle 31 is approximately 3.1t. Since the material transport vehicle 31 is operated by a driver in the driver's seat 55, it is safer than, for example, a flatbed truck.
[0031] The top surface of the cargo bed 57 is a horizontal, flat surface, and there is nothing to partition the cargo bed 57 other than the partition fence section 59, so the front, rear, left side, and top of the cargo bed 57 are open. Since the driver's seat 55 and the cargo bed 57 are arranged in the width direction of the vehicle, it is possible to have a layout in which the cargo bed 57 is positioned low. As a result, the material transport vehicle 31 can load shoring materials 29 at a low position, making it easy to use at construction sites with low headroom. The height of the cargo bed 57 from the ground is preferably, for example, 1.0 m or less. Also, since the driver's seat 55 and the cargo bed 57 are arranged in the width direction of the vehicle, it is possible to have a layout in which the cargo bed 57 is open to the front and rear. And because the cargo bed 57 is open to the front and rear, the material transport vehicle 31 can load shoring materials 29 that are longer than the length of the vehicle onto the cargo bed 57 so that they extend forward and backward. In this embodiment, the maximum length of the shoring material 29 is, for example, about 9m, and such long shoring material 29 can be loaded onto a loading platform 57 that is about 3m long. Furthermore, the material transport vehicle 31 can also transport long shoring material 29 that have been pre-assembled on the ground.
[0032] For example, forestry transport machinery may be repurposed as the material transport vehicle 31. Since this type of forestry transport machinery is used to transport timber and other materials in narrow and steep forests, it is also suitable for use in narrow excavation spaces 21 and for traveling on uneven ground in the central bottom surface 23b, and can be used without problems even if the central bottom surface 23b is uneven or sloped. Furthermore, when repurposing forestry transport machinery as the material transport vehicle 31, additional equipment such as head guards, headlights, seat belts, and drive recorders may be added as needed.
[0033] Next, the effects and advantages of the underground space construction method of this embodiment will be explained. In this embodiment, the underground space construction method involves excavating the ground directly beneath the existing operational railway track 1 to construct an underground structure 41 that extends in the longitudinal direction of the railway track 1, thereby constructing an underground space 37. In constructing this underground space 37, it is conceivable to temporarily remove a portion of the railway track 1 in order to set up routes for transporting support materials 29 and routes for discharging excavated soil. However, in this case, it is difficult to carry out excavation work while the railway track 1 is in operation, and work would have to be carried out at night when operations are suspended, for example, which could hinder the shortening of the construction period.
[0034] In contrast, according to the underground space construction method of this embodiment, in the under-track excavation process, the excavated soil generated during excavation is discharged to the surface from the side of the track 1 via the horizontal tunnel 17. Also, in the support structure construction process, support structure materials 29 are transported from the side of the track 1 to the excavation space 21 via the horizontal tunnel 17. In this way, it is possible to discharge excavated soil from the side of the track 1 and to transport support structure materials 29 from the side of the track 1 via the horizontal tunnel 17. Therefore, it is unnecessary to temporarily remove a part of the track 1 to create a route for discharging excavated soil or transporting support structure materials 29, and construction work under the track 1 can be carried out while the operation of the track 1 continues.
[0035] Furthermore, when transporting the support materials 29, the materials 29 are transported to the planned installation location within the excavation space 21 by the material transport vehicle 31 as described above. As mentioned above, the cargo bed 57 of the material transport vehicle 31 is located at a relatively low position, and the long support materials 29 can be loaded directly with their longitudinal direction facing the front-to-back direction of the vehicle, making the material transport vehicle 31 easy to use in the narrow, low-headroom excavation space 21. In addition, since the material transport vehicle 31 can travel on unleveled ground, there is no need to lay rails or steel plates for transporting the support materials 29 on the central bottom surface 23b. In particular, in the underground space construction method of this embodiment, the road excavation process and the support construction process are repeated alternately. Therefore, if rails or steel plates were to be used, it would be cumbersome to have to install the rails or steel plates in the support construction process and remove them in the road excavation process, and repeat this process alternately. In contrast, this embodiment uses a material transport vehicle 31 that can travel on uneven ground, eliminating the need for rails, steel plates, etc., and thus eliminating the complicated procedures described above.
[0036] The present invention can be implemented in various forms, including the embodiments described above, by making various changes and improvements based on the knowledge of those skilled in the art. It is also possible to construct modified versions by utilizing the technical matters described in the embodiments described above. The configurations of each embodiment may be used in appropriate combinations. The underground space construction method of the present invention can be applied not only to construction under railway tracks but also to construction under roads. [Explanation of Symbols]
[0037] 1...Tracks (existing operational line), 3...Temporary support structure, 17...Side tunnel, 21...Excavation space, 23a...High level section, 23b...Central bottom, 27...Shoring, 27b...Bracing, 29...Shoring materials, 31...Material transport vehicle, 41...Underground structure, 55...Driver's cab, 57...Cargo bed.
Claims
1. A method for constructing an underground space that extends in the longitudinal direction of an existing operational railway line beneath the existing operational railway line, A temporary support step involves constructing a temporary support structure below the existing operational line to temporarily support the existing operational line, A tunnel excavation process involves excavating a tunnel that extends from the side of the existing operational railway line and goes under the existing operational railway line, An underpass excavation process is performed by excavating from the horizontal tunnel in the longitudinal direction to excavate below the existing operational railway line, The process includes a support structure construction step, in which a support structure is constructed in the excavated space created in the road excavation step, In the aforementioned road excavation process, the excavated soil generated during the excavation is discharged to the surface from the side of the existing operational railway line via the horizontal tunnel. In the aforementioned support structure construction process, the support structure materials constituting the support structure are transported from the side of the existing operational railway line through the horizontal tunnel into the excavation space, in a method for constructing an underground space.
2. In the aforementioned shoring construction process, The aforementioned support materials are loaded onto the cargo bed of a designated material transport vehicle and transported through the excavation space from the horizontal tunnel to the planned installation site of the support structure. The aforementioned material transport vehicle is It has a driver's seat and a cargo bed arranged side by side in the width direction of the vehicle, the cargo bed is open to the front and rear, and travels on the bottom surface of the uneven ground in the excavated space. The method for constructing an underground space according to claim 1.
3. In the aforementioned shoring construction process, The method for constructing an underground space according to claim 2, wherein the shoring materials, which are longer than the length of the material transport vehicle, are loaded onto the material transport vehicle such that they protrude forward and backward from the loading platform in the direction of the vehicle length.
4. In the aforementioned shoring construction process, The aforementioned support materials are loaded onto the cargo bed of a designated material transport vehicle and transported through the excavation space from the horizontal tunnel to the planned installation site of the support structure. In the area of the excavation space through which the material transport vehicle passes, there are elevated sections located at both ends in the width direction of the existing operational line, and a central bottom surface lower than the elevated sections in the center in the width direction, and the bracing of the shoring is not yet installed. The method for constructing an underground space according to claim 1, wherein the material transport vehicle travels on the central bottom surface.
5. The method for constructing an underground space according to any one of claims 1 to 4, further comprising an underground structure construction step of constructing an underground structure in the aforementioned excavated space.
Citation Information
Patent Citations
Vehicle driving assistance device
JP6543117B2