Installation method of the housing

Abstract

To provide a box body installation method preventing friction with an FC plate when a steel pile is pressed in and shift of a natural ground on an upper part of the FC plate caused by the expansion and contraction of the FC plate when entering a box body.SOLUTION: A box body installation method comprises the steps of: a steel pile press-in preparation process of attaching, to a steel pipe 9 in a rectangular shape on which a cutting edge 13 is attached, a receiving pipe 15 in which a sheet-shaped member 14 wound up in a roll shape and allowed to be drew out of an upper part to install an FC plate 10 on an upper surface opposite to the cutting edge 13 than the receiving pipe 15; a box roof forming process of forming a box roof 9R while installing the sheet-shaped member 14 drew out through pressing-in the steel pipe 9 along an upper surface of the FC plate 10 after fixing an end of the sheet-shaped 14 on a start side; a leaving process of removing the sheet-shaped member 14 and the FC plate 10 from the steel pipe 9 and leaving them on a natural ground E; and a box body installation process of installing a box body 4 by pulling out the box roof 9R from the natural ground E through making the box body 4 enter a lower side of the FC plate 10.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a method for installing a casing, and more particularly to a method for installing a casing in a planned casing installation area of the ground under a facility in use without excavation.

Background Art

[0002] As a construction method for installing a casing (tunnel body), which is an underground structure, in the ground under a facility in use such as a railway or a road without excavation, an underpass method is known. Since the underpass method is a technique for forming a tunnel directly below while using the above-ground facility, it is used when the distance between the ground surface and the tunnel top surface is narrow and a shield method or the like cannot be used.

[0003] Among the techniques classified as the underpass method, for example, there are the R&C method (Roof & Culverts Method) and the SFT method (Simple and Face-Less Method of Construction of Tunnel). In both methods, after installing a plurality of steel pipes with a rectangular cross-section adjacent to each other along the outer periphery of the planned casing installation area from the starting side to the reaching side of the ground to form a box-shaped roof (pipe roof), the casing is installed in the planned casing installation area while pushing the box-shaped roof out of the ground.

[0004] In the case of these methods, on the box-shaped roof forming the tunnel top surface, a steel plate for friction cutting (edge cutting plate) called an FC plate is installed for each steel pipe. That is, the steel pipe with the FC plate installed on the upper surface is pressed into the ground to form a box-shaped roof, and when adding a steel pipe, this FC plate is also joined continuously. Then, when the steel pipe reaches the reaching side, the end of the FC plate is fixed to a fixing member provided outside the planned casing installation area. Also, when the casing is made to enter the ground while pushing out the box-shaped roof, the casing is made to pass under the FC plate.

[0005] At this time, due to the presence of the FC plate, the box-shaped roof and the upper surface of the casing do not come into contact with the upper natural ground, so the earth and sand of the upper natural ground do not shift in the advancing direction due to the advancement of the casing.

[0006] Regarding the method of installing the casing by the underpass method, for example, it is disclosed in Patent Document 1. This Patent Document 1 is an invention regarding the R&C method, and it describes providing an FC plate (edge-cut plate) on the upper surface of a box-shaped roof (steel pipe), removing the joint with the FC plate after installing the box-shaped roof, and leaving the FC plate during casing installation.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Here, it is desirable that the upper surface of the FC plate (edge-cut plate) is in a state where friction is unlikely to occur so as not to disturb the natural ground located above during the press-fitting of the steel pipe. Also, it is desirable that the lower surface of the FC plate is in a state where friction is unlikely to occur so as not to prevent the entry of the casing.

[0009] However, since the load of the upper natural ground is applied to the FC plate, frictional force will occur on the upper surface of the FC plate during the press-fitting of the steel pipe and on the lower surface of the FC plate during the installation of the casing.

[0010] That is, when the steel pipe is pressed in, a frictional force acts between the upper surface of the FC plate and the natural ground due to the load of the upper natural ground, and the FC plate may drag the natural ground. Further, when the casing is installed, the FC plate is pulled by the friction with the upper surface of the casing. However, since it is fixed to the fixing member provided outside the planned installation area of the casing, it will extend as the casing enters along with the upper natural ground. When the extension of the FC plate becomes large and its restoring force becomes larger than the static frictional force between the FC plate and the upper part of the casing, the friction between the two is broken and the FC plate shrinks suddenly while leaving the overlying natural ground in place.

[0011] And by repeating these, displacement may occur in the natural ground on the FC plate, which may affect the ground facilities (for example, the road bends).

[0012] The present invention has been made based on the above technical background, and an object thereof is to provide a technique for preventing displacement of the natural ground above the edge cutting plate due to friction with the edge cutting plate installed on the upper surface of the steel pipe during steel pipe pressing and the expansion and contraction of the edge cutting plate during casing entry.

Means for Solving the Problems

[0013] In order to solve the above problems, the method for installing a casing according to the present invention described in claim 1 is a method for installing a casing in a planned casing installation area of the natural ground without excavation, and when pressing a steel pipe with a rectangular cross-section into the natural ground from its starting side, a storage pipe in which a sheet-like member wound in a roll shape and capable of being pulled out from above is stored is attached to the steel pipe having a cutting edge attached to the tip in the pressing direction, and a friction cutting edge plate is installed on the upper surface on the side opposite to the cutting edge with respect to the storage pipe; a steel pipe pressing preparation step; fixing one end of the sheet-like member to a support wall on the starting side of the steel pipe in the planned casing installation area, and installing the sheet-like member pulled out from the storage pipe along with the pressing of the steel pipe along the upper surface of the edge cutting plate while installing a plurality of the steel pipes adjacent to each other along the upper part of the planned casing installation area to form a box-shaped roof; a box-shaped roof forming step; a leaving step of removing the sheet-like member and the edge cutting plate from the steel pipe and leaving them in the natural ground; and a casing installation step of causing the casing to enter from the starting side of the casing under the edge cutting plate of the natural ground and installing the casing in the planned casing installation area while pushing out the box-shaped roof from the natural ground.

[0014] The invention described in claim 2 is characterized in that, in the above-mentioned invention described in claim 1, in the leaving step, the other end of the sheet-like member is fixed to a support wall on the arrival side of the steel pipe in the planned casing installation area.

[0015] The invention described in claim 3 is characterized in that, in the above-mentioned invention described in claim 1 or 2, the edge cutting plate is fixed to the upper surface of the steel pipe with the tip side in the pressing direction of the steel pipe, and in the leaving step, at least the end portion on the starting side of the casing of the edge cutting plate is fixed to a fixing member provided outside the planned casing installation area.

[0016] The invention described in claim 4 is characterized in that, in the invention described in any one of claims 1 to 3 above, a friction reduction treatment for reducing the friction between the edge cutting plate and the sheet-like member is applied to at least one of the contact surface of the sheet-like member with the edge cutting plate and the contact surface of the edge cutting plate with the sheet-like member.

[0017] The invention according to claim 5 is characterized in that, in the invention according to claim 4, the friction reduction treatment is a treatment in which a lubricant is preliminarily applied or coated on the contact surface.

[0018] The invention according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, in the box-shaped roof forming step, a plurality of steel pipes having a rectangular cross-section with a blade edge attached to the tip in the press-fitting direction are installed adjacent to each other along the side surface of the planned installation area of the casing.

Advantages of the Invention

[0019] According to the present invention, when the steel pipe is press-fitted, the edge cutting plate is prevented from rubbing against the ground by the sheet-like member, and when the casing enters, even if the edge cutting plate expands and contracts, the sheet-like member prevents the edge cutting plate from affecting the upper ground. As a result, it is possible to prevent the friction between the edge cutting plate installed on the upper surface of the steel pipe during the press-fitting of the steel pipe and the displacement of the upper ground E of the edge cutting plate accompanying the expansion and contraction of the edge cutting plate when the casing enters.

Brief Description of the Drawings

[0020]

Figure 1

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Figure 16

Embodiments for Carrying Out the Invention

[0021] Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. In the drawings for explaining the embodiment, the same reference numerals are generally given to the same components, and the repeated explanation thereof is omitted.

[0022] The method for installing the casing of the present embodiment will be described with reference to FIGS. 1 to 16. Note that the reference numeral R indicates the rails (upward and downward lines) of a tram running on the road surface.

[0023] First, as shown in FIG. 1, after driving temporary earth retaining piles (support walls) 1 into the ground mountain E, by excavating between adjacent temporary earth retaining piles 1, two shafts 2 are formed on both sides in the width direction of the track so as to sandwich the track on which the rails R are installed. Note that the region sandwiched by these shafts 2 becomes the region where the casing described later is installed, that is, the planned casing installation region S. In the planned casing installation region S, a chemical solution for ground improvement is injected as necessary.

[0024] When shown in the drawings, the shaft 2 on the left side of the drawing is the starting shaft of the casing on the advancing side, and the shaft 2 on the right side of the drawing is the starting shaft of the box-shaped roof for pressing the steel pipe and installing the box-shaped roof. Then, the starting shaft of the casing on the advancing side is referred to as the advancing side shaft 2a, and the starting shaft of the box-shaped roof (that is, the shaft on the arrival side of the casing) is referred to as the arrival side shaft 2b for explanation. Note that the starting shaft of the casing on the advancing side and the starting shaft of the box-shaped roof on the advancing side may be reversed, and further, the starting shaft of the casing on the advancing side and the starting shaft of the box-shaped roof on the advancing side may be the same.

[0025] Next, as shown in FIG. 2, in the advancing side shaft 2a, after constructing the launching platform 3, the casing 4 is constructed on the launching platform 3, and a cutting edge Bm for cutting the natural ground E is installed at the periphery of the tip portion in the entering direction of the casing 4. On the other hand, in the arrival side shaft 2b, after constructing the launching platform 5, a gantry 6 for propelling the steel pipe described later is constructed on the launching platform 5. Then, a support body 7 is installed on the temporary earth retaining pile 1 on the opposite side of the propelling direction of the steel pipe, and a propelling jack 8 for pressing the steel pipe into the natural ground E is installed on the gantry 6 so as to take the reaction force with the support body 7. Next, after installing the steel pipe 9 on the gantry 6 by a crane truck (not shown), an FC plate (edge cutting plate) 10 made of steel plate for friction cutting is installed on the steel pipe 9 by a crane truck (not shown). Then, the steel pipe 9 is propelled by the propelling jack 8 toward the advancing side shaft 2a on the opposite side and pressed into the ground wall surface, and a plurality of steel pipes 9 are installed adjacent to each other along the upper part of the casing installation planned area S.

[0026] Here, FIG. 3 shows the casing 4 installed by the casing installation method of the present embodiment.

[0027] The casing 4 is a structure for constructing a structure such as an underground pedestrian crossing, and has a hollow structure. The casing 4 includes an upper slab 4a and a lower slab 4b facing each other in the vertical (height) direction, and a pair of side plates 4c, 4d facing each other in the lateral direction at both ends thereof. Further, the front and rear are opened as an opening 4e. When a plurality of casings 4 are used, they are arranged in a vertical row in a state where the openings 4e of the casings 4 communicate with each other.

[0028] In the vicinity of the four corners of the front surface of the casing 4, fixing material insertion holes 4f extending along the advancing direction of the casing 4 (the longitudinal direction of the steel pipe 9) are formed in a penetrating state, and a notch groove 4g opening to the inside of the casing 4 is formed in the middle of the fixing material insertion hole 4f. In order to fix adjacent casing structures 10 to each other, bolts are inserted into the fixing material insertion holes 4f as fixing materials, and are fixed by tightening nuts in the notch grooves 4g.

[0029] Furthermore, grout holes 4h for injecting grout material after installation are formed in a penetrating state in the central portions of the upper slab 4a, the lower slab 4b, and the side plates 4c and 4d. Note that there are two types of casings 4, one with grout holes 4h formed and the other without.

[0030] In this embodiment, three steel pipes 9 are connected and penetrated from the arrival-side shaft 2b to the departure-side shaft 2a (see FIG. 11), and struts 11 and spacers 12 are appropriately arranged between the propulsion jack 8 and the steel pipe 9 to transmit the propulsion force of the propulsion jack 8 to the steel pipe 9. However, the number of connected steel pipes 9 varies depending on the length of the steel pipe 9 and the distance from the arrival-side shaft 2b to the departure-side shaft 2a, or it may be possible to use only one steel pipe 9 without connection. Therefore, it is not limited to connecting three steel pipes 9 as in this embodiment.

[0031] Here, the steel pipe 9 pressed into the ground E will be described with reference to FIGS. 4 to 9. FIG. 4 is a perspective view showing the tip of the steel pipe, FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4, FIG. 6 is a plan view showing the inside of FIG. 4 in a see-through manner, FIG. 7 is a cross-sectional view taken along line B-B of FIG. 5, FIG. 8 is a side view showing the inside of the steel pipe in a see-through manner when it is being pressed into the ground, and FIG. 9 is an enlarged cross-sectional view showing part C of FIG. 8.

[0032] As shown in FIGS. 4 to 6, the steel pipe 9 has a rectangular cross-sectional shape with openings at the front end and the rear end (not shown) in the press-fitting direction. In this embodiment, the outer width is 800 mm, the outer height is 810 mm, and the thickness is 19 mm. Therefore, a space is secured inside the steel pipe 9 where an operator can enter. Further, a cutting edge 13 is attached to the front end of the steel pipe 9 in the press-fitting direction. The cutting edge 13 is formed to be inclined such that the upper side leads in a side view, and includes a hood-shaped cutting edge portion 13a for excavating the natural ground E, and a cylindrical cutting edge attachment portion 13b to which the cutting edge portion 13a is attached and which has the same rectangular cross-section as the steel pipe 9. Then, as will be described later, during press-fitting, the operator H enters the cutting edge attachment portion 13b (FIG. 8) to excavate the press-fitting surface of the steel pipe 9 or to perform an operation of discharging the excavated earth and sand to the outside. Note that the steel pipe 9 is not limited to the above dimensions and can be freely set.

[0033] A storage pipe 15 in which a sheet-like member 14 wound in a roll shape and pullable out from above is stored is provided between the steel pipe 9 and the cutting edge 13. The sheet-like member 14 is a tough and flexible member composed of a thin steel plate, and the pulled-out portion covers the upper surface of the aforementioned FC plate 10. In this embodiment, a friction reduction treatment in which a lubricant is applied or coated in advance is performed on the contact surface of the sheet-like member 14 with the FC plate 10.

[0034] As shown in Fig. 7, at the four corners on the cutting edge 13 side within the storage pipe 15, there are ribs Fa extending in the front-rear direction, fastening holes Fb for bolt penetration are formed, and a reinforcing flange F with an arcuate inner circumference is provided. Further, as shown in Figs. 5 and 6, such a flange F is also provided at the four corners on the side opposite to the cutting edge 13 within the storage pipe 15, and at the four corners on the storage pipe 15 side within the cutting edge attachment portion 13b constituting the cutting edge 13. Furthermore, at the four corners within the tip of the steel pipe 9, a flange F with the fastening hole Fb formed is provided. Then, as shown in Fig. 8, the steel pipe 9 and the storage pipe 15 are fastened via the fastening hole Fb by a fastener J composed of a bolt and a nut, and the cutting edge 13 and the storage pipe 15 are fastened. In the case of a construction method using a slit pipe (not shown) to cut the FC plate on the lower surface, a storage pipe is provided between the slit pipe and the cutting edge 13.

[0035] Now, as shown in Figs. 4 and 5, the aforementioned FC plate 10 has the tip side in the press-fitting direction of the steel pipe 9 fixed by welding a round steel (not shown), and is installed on the upper surface of the steel pipe 9 on the side opposite to the cutting edge 13 from the storage pipe 15.

[0036] Then, before the steel pipe 9 is press-fitted into the ground wall surface with the propulsion jack 8 and propelled toward the starting shaft 2a, as described above, the cutting edge 13 is attached to the tip in the press-fitting direction of the steel pipe 9, and a storage pipe 15 in which a sheet-like member 14 wound in a roll shape and capable of being pulled out from above is stored is attached, and the FC plate 10 is installed (steel pipe press-fitting preparation process).

[0037] Now, when such a steel pipe 9 is propelled by a propulsion jack 8 and pressed into the ground E as shown in FIG. 2, a sheet-like member 14 is pulled out in advance and one end thereof is fixed to a temporary earth retaining pile 1 on the starting side of the planned installation area S of the casing (here, the temporary earth retaining pile 1 on the planned installation area S side in the arrival-side shaft 2b). As a result, as shown in FIGS. 8 and 9, when the steel pipe 9 is propelled, the sheet-like member 14 is pulled out from the storage pipe 15 and installed along the upper surface of the FC plate 10 as the steel pipe 9 is propelled. Then, as described above, a plurality of steel pipes 9 are installed adjacent to each other along the upper part of the planned installation area S of the casing to form a box-shaped roof (box-shaped roof forming step).

[0038] In this way, as the steel pipe 9 is propelled, the sheet-like member 14 is pulled out and installed along the upper surface of the FC plate 10, so that the contact between the FC plate 10 and the ground E located above is blocked by the sheet-like member 14, and no frictional force is generated on the FC plate 10. That is, the sheet-like member 14 pulled out from the storage pipe 15 only stays in place and does not move. Therefore, when such a sheet-like member 14 is interposed between the FC plate 10 and the ground E, the FC plate 10 will not be dragged by the load of the upper ground E and displaced during the propulsion of the steel pipe 9.

[0039] In addition, since the contact surface of the sheet-like member 14 with the FC plate 10 is subjected to a friction reduction treatment, the FC plate 10 propelled together with the steel pipe 9 is likely to slide with respect to the sheet-like member 14, so that the displacement of the ground E caused by the FC plate 10 during the propulsion of the steel pipe 9 described above can be more reliably prevented, and the steel pipe 9 can be smoothly propelled into the ground E. Note that the sheet-like member 14 does not necessarily have to be subjected to a friction reduction treatment, but it is desirable to perform such a treatment in order to smoothly propel the steel pipe 9.

[0040] When pushing the steel pipe 9, as shown in Fig. 8, an operator H enters the cutting edge attachment part 13b to excavate the press-fitting surface of the steel pipe 9, or to perform operations such as discharging the excavated soil generated during press-fitting to the outside by a trolley running inside the steel pipe 9 or an auger installed inside the steel pipe 9.

[0041] Once the box-shaped roof is formed, next, the FC plate 10 and the sheet-like member 14 are removed from the steel pipe 9 and left on the natural ground E (residual placement process).

[0042] That is, the opposite side of the sheet-like member 14 whose one end is fixed to the temporary earth retaining pile 1 on the starting side of the planned installation area S of the casing (here, the temporary earth retaining pile 1 on the planned installation area S side in the arrival-side shaft 2b) is cut, and the storage pipe 15 and the cutting edge 13 attached to the storage pipe 15 are removed. Then, the other end (cut end) of the sheet-like member 14 is fixed to the temporary earth retaining pile 1 on the arrival side of the planned installation area S of the casing (here, the temporary earth retaining pile 1 on the planned installation area S side in the starting-side shaft 2a) and left in the natural ground E. Also, the FC plate 10 is removed from the steel pipe 9, and at least the end part on the starting side of the casing is fixed to a fixing member (not shown) installed on the outside of the starting side of the casing at both ends of the planned installation area S of the casing and left in the natural ground E. And as described above, since the steel pipe 9 is pushed while installing the sheet-like member 14 along the upper surface of the FC plate 10, it is left in a state where the sheet-like member 14 is interposed between the FC plate 10 and the natural ground E.

[0043] In this embodiment, it is stated that the end part on the starting side of the casing of the FC plate 10 is fixed to a fixing member installed on the outside of the starting side of the casing in the planned installation area S of the casing, but both ends of the FC plate 10 may be fixed to fixing members installed at both ends of the planned installation area S of the casing.

[0044] Note that the remaining process and the box-shaped roof forming process described above may be performed alternately. That is, instead of performing the remaining process after the formation of the box-shaped roof, each time one or more steel pipes 9 are passed through the planned installation area S of the casing, the FC plate 10 and the sheet-like member 14 are left on the ground E. Also, as described below, in the case of the present embodiment in which a portal-shaped box-shaped roof is formed, the remaining process may be performed after the formation of the portal-shaped roof and before the propulsion of the casing 4.

[0045] Here, the shape of the box-shaped roof includes, for example, a single-character type in which a plurality of steel pipes 9 are arranged in a horizontal row adjacent to each other along the upper part of the planned installation area S of the casing, and further, a plurality of steel pipes 9 are arranged in a vertical row adjacent to each other from both sides of the single-character type (that is, a plurality of steel pipes 9 are arranged adjacent to each other along the side surface of the planned installation area S of the casing), such as a portal type. That is, since the single-character type is also a shape of the box-shaped roof, the process of installing the steel pipes 9 in the single-character type is referred to as the "box-shaped roof forming process". However, in the present embodiment, since a portal-shaped box-shaped roof is formed, it is referred to as the "box-shaped roof forming process" again at the stage when the portal-shaped box-shaped roof is formed.

[0046] Now, if the work of installing the steel pipes 9 along the upper part of the planned installation area S of the casing is performed from the arrival-side shaft 2b side in this way, as shown in FIG. 10, while gradually lowering the height of the gantry 6, a plurality of steel pipes 9 with a rectangular cross-section to which the cutting edge 13 is attached are installed adjacent to each other along the side surface of the planned installation area S of the casing to form a portal-shaped box-shaped roof (box-shaped roof forming process).

[0047] A portal-shaped box-shaped roof 9R composed of a plurality of steel pipes 9 is shown in FIG. 11. As shown in the figure, the FC plate 10 is located on the upper surface of the box-shaped roof 9R, and further, a sheet-like member 14 covering the FC plate 10 is located on the upper surface of the FC plate 10.

[0048] Note that, unlike the steel pipes 9 installed in a vertical row along the side surface of the planned installation area S of the casing, no storage pipes 15 containing the FC plates 10 and the sheet-like members 14 are provided for the steel pipes 9 installed in a horizontal row along the upper part of the planned installation area S of the casing. This is because the steel pipes 9 installed along the side surface of the planned installation area S of the casing do not come into contact with the upper natural ground E. However, from the perspective of reducing the influence of the earth pressure received by the steel pipes 9 arranged in a vertical row from the lateral natural ground E, the FC plates 10, or the storage pipes 15 containing the FC plates 10 and the sheet-like members 14 may be provided on the side of the natural ground E.

[0049] Now, after forming the box-shaped roof 9R, as shown in FIG. 12, on the side of the arrival shaft 2b, the equipment (such as the gantry 6, the support body 7, the propulsion jack 8, the strut 11, the spacer 12, etc.) used for forming the box-shaped roof 9R is removed, and a guide drift 16 for controlling the posture of the entering casing 4 is constructed. Also, on the side of the departure shaft 2a, a reaction wall 17 of the shaft girder frame for allowing the casing 4 to enter the planned installation area S of the casing is constructed. Note that in FIGS. 12 to 15, for the sake of avoiding complication of the drawing, the steel pipes 9 installed in a vertical row are omitted.

[0050] Next, as shown in FIG. 13, the propulsion equipment of the casing 4 is constructed. On the side of the departure shaft 2a, a pushing jack 18 is installed between the casing 4 and the reaction wall 17, and on the side of the arrival shaft 2b, a box-shaped roof removal gantry 19 is installed. Note that, as described above, at this stage, the process of leaving the FC plates 10 and the sheet-like members 14 on the natural ground E may be executed.

[0051] Next, as shown in FIG. 14, a spacer 20 is installed between the pushing jack 18 and the casing 4, and the casing 4 is advanced toward the planned installation area S of the casing by the pushing jack 18 via the spacer 20. Then, the cutting edge Bm installed at the tip of the casing 4 is penetrated into the ground wall surface.

[0052] Then, as shown in FIG. 15 and subsequent FIG. 16, while appropriately adding spacers 20 and struts 21 between the platen jack 18 and the casing 4, the casing 4 is advanced into the planned casing installation area S by the platen jack 18. Along with this, the box-shaped roof 9R is pushed out onto the box-shaped roof removal stand 19 installed on the side of the arrival shaft 2b from the ground E, and the casing 4 is installed in the planned casing installation area S (casing installation process). The pushed-out box-shaped roof 9R is removed by a crane vehicle (not shown) or the like.

[0053] Once the casing 4 is installed in the planned casing installation area S, after joining the casings 4 together with bolts and nuts inserted through the fixing material insertion holes 4f, the cutting edge Bm installed on the casing 4 is removed, and the equipment (reaction wall 17, platen jack 18, spacer 20, strut 21) for allowing the casing installed on the departure shaft 2a side to enter and the box-shaped roof removal stand 19 installed on the arrival shaft 2b side are removed. Further, backfill grout is injected around the outer periphery of the casing 4. When installing a plurality of casings 4 in the planned casing installation area S, these operations are performed after all the casings are installed.

[0054] Here, in the remaining process described above, the FC plate 10 and the sheet-like member 14 are left on the ground E, and in the casing installation process, the casing is advanced under the FC plate 10. At this time, as described above, the sheet-like member 14 is interposed between the FC plate 10 and the upper ground E, and the contact between the FC plate 10 and the ground E is interrupted. Even if the FC plate 10 expands and contracts due to friction with the casing 4 when installing the casing 4, the sheet-like member 14 does not move or deform, so the FC plate 10 does not affect the upper ground E and the displacement of the ground E is prevented.

[0055] Therefore, as described above, in combination with the fact that the FC plate 10 no longer slides on the ground E when the steel pipe 9 is press-fitted by the sheet-like member 14, it becomes possible to prevent the displacement of the ground E above the FC plate 10 due to the friction between the FC plate 10 installed on the upper surface of the steel pipe 9 when the steel pipe 9 is press-fitted and the expansion and contraction of the FC plate 10 when the casing 4 enters. As a result, there is no risk of displacement occurring in the ground E on the FC plate 10 and having an adverse effect on the facilities on the ground.

[0056] Note that since the contact surface of the sheet-like member 14 with the FC plate 10 is subjected to a friction reduction treatment, the FC plate 10 becomes more likely to slide relative to the sheet-like member 14, and the influence when the FC plate 10 expands and contracts when the casing 4 enters is less surely imparted to the sheet-like member 14. As a result, it is possible to more surely prevent the displacement of the ground E above the FC plate 10 due to the expansion and contraction of the FC plate 10 when the casing 4 enters.

[0057] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the embodiments disclosed in this specification are illustrative in all respects and are not limited to the disclosed technology. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above embodiments, but should be construed in accordance with the description of the claims. All modifications that do not depart from the gist of the claimed technology and all changes within the scope of equivalents of the claimed technology are included.

[0058] For example, in the present embodiment, the contact surface of the sheet-like member 14 with the FC plate 10 is subjected to a friction reduction treatment in which a lubricant is applied or coated in advance. However, such a friction reduction treatment may be performed on either the contact surface of the FC plate 10 with the sheet-like member 14 or both contact surfaces, namely, the contact surface of the sheet-like member 14 with the FC plate 10 and the contact surface of the FC plate 10 with the sheet-like member 14.

[0059] Furthermore, the friction reduction treatment is not limited to the application or coating of lubricants. As long as the contact surface is finished smoothly and it is difficult for friction to occur, that is sufficient. Since the sheet-like member 14 is pulled out from the storage pipe 15 and only stays in place without moving, there is no problem of friction on the upper surface of the sheet-like member 14 (that is, the contact surface with the base E). Therefore, a treatment such as a friction reduction treatment that makes it difficult for friction to occur is unnecessary.

[0060] Furthermore, in this embodiment, the case of using a plurality of casing bodies 4 connected together is described. However, even when the casing body 4 consists of a single member, it can be constructed in the same manner. In that case, it is not necessary to provide the fixing material insertion holes 4f and the cutout grooves 4g.

Industrial Applicability

[0061] The present invention is not limitedly applicable to the R&C method, and can be applied to other construction methods (such as the SFT method) in which the casing body is inserted while extruding a box-shaped roof formed in the ground and installed in the planned installation area of the casing body.

Explanation of Reference Numerals

[0062] 1 Temporary earth retaining pile (support wall) 2 Shaft 2a Starting side shaft 2b Arrival side shaft 3 Starting platform 4 Casing body 5 Starting platform 6 Gantry 7 Support pressure body 8 Propulsion jack 9 Steel pipe 9R Box-shaped roof 10 FC plate (edge cutting plate) 11 Strut 12 Spacer 13 Cutting edge 13a Cutting edge tip 13b Cutting edge mounting part 14 Sheet-like member 15 Storage pipe 16 Guide adit 17 Reaction wall 18 yuan pressing jack 19 box-shaped roof removal stand 20 spacer 21 strut Bm cutting edge E base F flange Fa rib Fb fastening hole J fastener S planned area for installing the box body

Claims

1. A method for installing a casing in a planned installation area of the ground without excavation, comprising: When pressing a steel pipe with a rectangular cross-section into the ground from its starting side, a storage pipe containing a sheet-like member wound in a roll and pullable from above is attached to the steel pipe with a cutting edge attached to the tip in the pressing direction, and a cut-off plate for friction cutting is installed on the upper surface on the side opposite to the cutting edge from the storage pipe; a steel pipe pressing preparation step; Fixing one end of the sheet-like member to the support wall on the starting side of the steel pipe in the planned installation area of the casing, and installing the sheet-like member pulled out from the storage pipe along the upper surface of the cut-off plate while installing a plurality of the steel pipes adjacent to each other along the upper part of the planned installation area of the casing to form a box-shaped roof; a box-shaped roof forming step; Removing the sheet-like member and the cut-off plate from the steel pipe and leaving them in the ground; a leaving step; Entering the casing from the starting side of the casing under the cut-off plate of the ground, and installing the casing in the planned installation area of the casing while pushing out the box-shaped roof from the ground; a casing installation step; A method for installing a casing, characterized by performing the above steps.

2. In the leaving step, the other end of the sheet-like member is fixed to the support wall on the reaching side of the steel pipe in the planned installation area of the casing. The method for installing a casing according to claim 1, characterized by the above.

3. The cut-off plate is fixed to the tip side in the pressing direction of the steel pipe and installed on the upper surface of the steel pipe. In the leaving step, at least the end on the starting side of the casing of the cut-off plate is fixed to a fixing member provided outside the planned installation area of the casing. The method for installing a casing according to claim 1 or 2, characterized by the above.

4. At least one of the contact surface of the sheet-like member with the cut-off plate and the contact surface of the cut-off plate with the sheet-like member is subjected to a friction reduction treatment for reducing the friction between the cut-off plate and the sheet-like member. The method for installing a casing according to any one of claims 1 to 3, characterized by the above.

5. The friction reduction treatment is: A treatment in which a lubricant is pre-applied or coated on the contact surface. The method for installing a casing according to claim 4, characterized by the above.

6. In the box-shaped roof forming step: Furthermore, a plurality of steel pipes with a rectangular cross-section and a cutting edge attached to the tip in the pressing direction are installed adjacent to each other along the side surface of the planned installation area of the casing. The method for installing the casing according to any one of claims 1 to 5, characterized in that...

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