Installation method of the housing

Abstract

To provide a box body installation method capable of preventing the occurrence of a defective portion in the ground between the pipe roof and the box body when inserting the box body below the pipe roof.SOLUTION: The box body installation method includes: a first step in which a blade mouth Bm is installed to the head of propulsion direction of the box body 11a and a magazine M that stores a sheet-like member Sh rolled in a roll to be pulled out in the blade mouth Bm is mounted; and a second step in which one end of the sheet-like member Sh is fixed to the starting side end of the box body installation area S and causes the box body 11 to proceed to the underside of pipe roof 8R, and the sheet member Sh which is pulled out from the magazine M as the box body 11 proceeds is fixed along the outer surface of the box body 11 while cutting the ground E with blade mouth Bm, thus, the box body 11 is installed in the box body planned area S.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for installing a casing, and more particularly to a technique for preventing loosening of the ground when installing a casing under a pipe roof constructed of a plurality of steel pipes inserted into the ground in an underpass construction.

Background Art

[0002] The underpass method is a construction method for constructing an urban tunnel without excavation. That is, it is a method of excavating the lower ground while using facilities such as railways and roads, and constructing a tunnel by installing a casing such as a box culvert. Note that the routes of facilities such as railways and roads intersect with the route of the tunnel.

[0003] As one of such underpass methods, in order to prevent settlement and deformation of the upper facilities, a plurality of steel pipes (pipes) are inserted outside the planned installation area of the casing so as to cover the upper surface, or the upper surface and both side surfaces of the casing, to construct a pipe roof as a protective member, and a casing as a main body structure is installed below the pipe roof. This method is known.

[0004] In this method, the steel pipes are arranged continuously with as little gap as possible in the width direction and the vertical direction of the casing, and penetrate from the starting side to the reaching side of the ground. Further, the steel pipe has a rectangular or circular hollow cross section, and is inserted into the ground while excavating the face from the inside of the hollow part. After a set of steel pipes reaches the reaching side from the starting side (the insertion is completed), the adjacent steel pipes are inserted from the starting side.

[0005] Further, while advancing the steel pipe, a filler is injected into the ground from an injection hole provided at the upper end. The filler is for ensuring the looseness generated in the ground above by inserting the steel pipe. Therefore, as the filler, those having water stoppage and curability are preferable. Note that the injection of the filler is performed after inserting the steel pipe by a predetermined distance (for example, one piece of the steel pipe), stopping excavation and insertion, protecting the front with an earth retaining member, and stabilizing the ground of the face.

[0006] If a pipe roof is constructed by inserting a steel pipe into the ground in this way, a casing is inserted below it. At that time, the construction is carried out so as to maintain a predetermined interval between the pipe roof and the upper surface of the casing. Further, the front surface of the casing facing the face is open, and a cutting edge is provided on its outer periphery. Then, the casing is advanced while excavating the face from the inside of the opening of the casing, and the construction is carried out to the arrival side.

[0007] In addition, as a technique for protecting the front of the steel pipe with an earth retaining member, there is a technique described in Japanese Patent Application Laid-Open No. 2018-172929 (Patent Document 1). As a technique for preventing the occurrence of road surface settlement and the like when the casing enters below the pipe roof, there is a technique described in Japanese Patent Application Laid-Open No. 2007-138466 (Patent Document 2).

[0008] Patent Document 1 describes a technique in which while the excavation work of a hollow pipe member (steel pipe) is paused, an airbag member is set on the cutting edge member of the hollow pipe member where the excavation work is paused, the airbag member is inflated, and its tip surface portion is pressed against and adhered to the face surface, and at the same time, the side peripheral surface portion of the inflated airbag member is pressed against the inner peripheral surface of the cutting edge member to obtain a support reaction force, thereby retaining the face with soil.

[0009] Further, Patent Document 2 describes a technique in which a friction cut plate for cutting the frictional force with the ground is installed on the upper surface of the casing so that the soil of the ground is not disturbed when the casing is propelled. This friction cut plate reduces the friction between the upper surface of the casing and the ground, is arranged in a stripe shape in the advancing direction of the casing, is fixed to the upper surface of the casing, and moves forward as the casing advances.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0011] Here, in the underpass method described above, there is undisturbed ground under the pipe roof, which supports the pipe roof from below. This ground may be carried in the advancing direction due to friction with the casing or the cutting edge as the casing enters, or may collapse from the tip of the casing, resulting in partial loss.

[0012] Especially when the width of the casing is wide, since the casings of that width enter simultaneously, the influence on the ground between the pipe roof and the casing due to the entry of the casing becomes greater, and the loss becomes greater.

[0013] Furthermore, when the length of the casing increases, the loosening of the ground increases due to the accumulation of these losses, and as a result, there is a risk of settlement and deformation in the facilities and equipment constructed on the ground.

[0014] The present invention has been made based on the above technical background, and an object thereof is to provide a technique capable of preventing the occurrence of a missing part in the ground between the pipe roof and the casing when the casing enters below the pipe roof.

Means for Solving the Problems

[0015] To solve the above problems, the method for installing a casing according to the invention described in claim 1 is Pipe a method for installing a casing in which the casing is propelled under the roof and installed in the planned installation area of the casing, A first step of constructing a pipe loop for protecting a casing to be installed by inserting a plurality of steel pipes having injection holes formed at predetermined intervals along the axial direction into the ground so that the injection holes face the side of the planned casing installation area and are adjacent to each other; a cutting edge is installed at the tip of the casing at the leading end of the advancing direction, and a case body in which a sheet-like member wound in a roll and capable of being pulled out is housed is mounted in the cutting edge Second stepAnd, one end of the sheet-like member is fixed to the starting-side end of the planned installation area of the casing, and the casing is propelled under the pipe roof. While cutting the ground with the cutting edge, the sheet-like member pulled out from the case body along with the propulsion of the casing is installed along the outer surface of the casing, and the casing is installed in the planned installation area of the casing. Third step And The third step includes injecting rigid urethane foam between the injection hole and a sheet-like member installed along the outer surface of the casing and the pipe loop when the leading casing during entry reaches each injection hole formed in the steel pipe. It is characterized by the above.

[0016] In the method for installing a casing according to the invention described in claim 2, in the invention described in claim 1, a friction reduction treatment for reducing friction with the propelled casing is performed on the contact surface of the sheet-like member with the outer surface of the casing. It is characterized by this.

[0017] In the method for installing a casing according to the invention described in claim 3, in the invention described in claim 2, the friction reduction treatment of the sheet-like member is a treatment of pre-coating a lubricant on the contact surface, or a treatment of applying a lubricant with a lubricant-impregnated member to the contact surface of the sheet-like member when it is pulled out from the case body. It is characterized by this.

[0019] Claim 4 The method for installing a casing according to the invention described in Claim 3 In the invention described, the pipe roof is a single-row type in which a plurality of steel pipes are inserted into the ground so as to be adjacent to each other above the planned installation area of the casing, or a portal type in which a plurality of steel pipes are inserted into the ground so as to be adjacent to each other above and on both outer sides of the planned installation area of the casing. The rigid urethane foam is injected between at least the pipe roof located above the casing and the sheet-like member installed along the upper surface of the casing. It is characterized by this.

[0020] Claim 5 The method for installing a casing according to the invention described in Claims 1 to 4 In the invention according to any one of the above, the Third step In this case, the casing is installed under the pipe roof by a method of entering while excavating the ground in front from the opening on the advancing direction side of the casing. It is characterized by this.

Effect of the Invention

[0021] According to the present invention, as the casing is propelled, the sheet-like member is pulled out from the case body and installed along the outer surface of the casing. Thus, the edge between the ground and the outer surface of the casing is blocked by the sheet-like member, and the soil of the ground is not dragged by the forward movement of the casing. Thereby, it becomes possible to prevent the occurrence of a missing part in the ground between the pipe roof and the casing.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0023] 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.

[0024] The method for installing the casing in this embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is an explanatory diagram showing the process of constructing a pipe roof on the natural ground in one embodiment of the present invention, FIG. 2 is a front view showing the pipe roof constructed by the process of FIG. 1, FIG. 3 is an explanatory diagram showing the casing at the leading end in the propulsion direction, the cutting edge installed at the tip of the casing, and the magazine attached to the cutting edge, FIG. 4 is an explanatory diagram showing the process of entering and installing the casing under the pipe roof, FIG. 5 is an enlarged view of the main part when installing the casing in the process of FIG. 4, and FIG. 6 is a front view showing the constructed pipe roof and the casing installed under it. In FIGS. 1 and 4, the reference symbol R indicates a road provided on the surface of the natural ground.

[0025] Here, for the installation of the casing 11 in this embodiment, a construction method combining the FJ method (FRONTE JACKING METHOD) and the ESA method (ENDLESS SELF ADVANCING METHOD) is used.

[0026] The FJ method is a method in which, after the construction of the pipe roof 8R (see FIG. 2) is completed, a through hole is provided in the installation range of the casing 11 in the natural ground E, a PC steel wire is installed, the starting side of the PC steel wire is connected to the casing 11, and the reaching side is connected to a traction jack (front jack) J2 (see FIG. 3), so as to pull and advance the casing 11 from the reaching side. The ESA method is a method in which each casing 11 composed of three or more pieces in the axial direction is connected by a PC steel wire, jacks are installed between each piece and at the rearmost part, the tail part of the piece is fixed and the head part is advanced, and then the head part is fixed and the tail part is pulled. By repeating this movement, the casing 11 is sequentially advanced one piece at a time using the reaction force of the other casing 11. By using a construction method combining the FJ method and the ESA method, the casing 11 can be efficiently advanced by pulling the casing 11 (FJ method) and advancing the casing 11 by the reaction force (ESA method).

[0027] Now, as shown in FIG. 1, by driving and excavating the temporary retaining piles 1 on both sides of the planned installation area (the casing installation planned area S) of the casing 11 (see FIGS. 4 and 6) in the natural ground E, two vertical shafts 2 that are working spaces are formed so as to sandwich the road R. Subsequently, after constructing the support wall 3 and the launching platform 4 in one of the vertical shafts 2, the shaft girder form 5 is constructed. Then, after constructing the gantry 6 for propelling the pipe 8 described later, a propulsion machine 7 such as a propulsion jack is installed on the gantry 6.

[0028] Then, a pipe (steel pipe) 8 is installed on the gantry 6 by a crane vehicle or the like, and is propelled and pressed into the opposite vertical shaft 2 by the propulsion machine 7. The excavated soil generated inside the pipe 8 during the pressing process is discharged to the outside by a conveying device such as an auger. However, in the case of a pipe 8 thick enough for an operator to work inside, the process of the operator excavating the pressing surface of the pipe 8 and the process of pressing the pipe 8 by the propulsion machine 7 may be repeated.

[0029] In the present embodiment, a pipe 8 having a circular cross-section in the cross-axis direction is used, but a pipe having a rectangular cross-section in the cross-axis direction may also be used. Further, when one pipe 8 cannot reach from one vertical shaft 2 to the opposite vertical shaft 2, a plurality of pipes 8 are connected in series and pressed in.

[0030] Here, injection holes 8a (FIG. 5) are formed in the pipe 8 at predetermined intervals along the axial direction. These injection holes 8a are holes for injecting rigid foam urethane UF between the pipe loop 8R formed by pressing the pipe 8 into the natural ground E and the casing 11, as described later. Therefore, when the pipe 8 is pressed into the natural ground E, the injection holes 8a are oriented toward the casing installation planned area S (FIG. 2).

[0031] When the pressing of the first pipe 8 is completed, the next pipe 8 is pressed adjacent to that pipe 8, and the process of further pressing the next pipe 8 adjacent to that pipe 8 is repeated. In this way, as shown in FIG. 2, a pipe loop 8R composed of a plurality of pipes 8 for protecting the installed casing 11 is formed.(First step) 。

[0032] In this embodiment, the arrangement shape of the pipe roof 8R is in a portal shape. That is, a plurality of pipes 8 are installed adjacent to each other along the upper side and the outer sides of both sides of the planned installation area S of the casing. However, the arrangement shape of the pipe roof 8R is not limited to the portal shape. For example, a single-row shape in which a plurality of pipes 8 are installed adjacent to each other along the upper side of the planned installation area S of the casing may be used, among others.

[0033] Now, if the pipe roof 8R is constructed, the casing 11 is propelled below the pipe roof 8R and installed in the planned installation area S of the casing. Here, prior to the propulsion of the casing 11, as shown in Fig. 3(a), a cutting edge Bm for excavating the ground during the propulsion of the casing 11 is installed at the tip of the leading casing 11a in the propulsion direction. Next, as shown in Fig. 3(b), a magazine (case body) M in which a sheet-like member Sh wound in a roll shape and capable of being pulled out is stored is mounted inside the installed cutting edge Bm. (Second step) 。

[0034] Here, the sheet-like member Sh is composed of a thin steel plate and is a tough and flexible member. Also, as the casing 11 is propelled, as will be described later, the sheet-like member Sh is pulled out from the magazine M. At this time, a lubricant is pre-coated on the surface of the sheet-like member Sh that contacts the outer surface of the casing 11 (the contact surface with the outer surface of the casing 11), that is, a friction reduction treatment is performed, so that the propelled casing 11 slides easily with respect to the sheet-like member Sh, and the frictional force during casing propulsion is reduced. Note that the friction reduction treatment does not necessarily have to be performed on the sheet-like member Sh, but it is desirable to perform the treatment in order to smoothly propel the casing 11.

[0035] In FIG. 3, the magazine M is mounted within the cutting edge Bm located at the uppermost part of the casing 11a, but it is also mounted within the cutting edges Bm located on both sides of the casing 11a. However, the magazine M containing the sheet-like member Sh may be mounted only within the cutting edge Bm located at the uppermost part of the casing 11a, or only within the cutting edges Bm located on both sides of the casing 11a.

[0036] Also, the width of one magazine M (in other words, the width of the sheet-like member Sh) may be the width of the casing 11a (when mounted within the cutting edge Bm located at the uppermost part of the casing 11a) or the height of the casing 11a (when mounted only within the cutting edge Bm located on the side part of the casing 11a), but it is shorter than the width or height of the casing 11a, and they may be mounted side by side in the horizontal or vertical direction. In that case, the distance between the magazines M may be open or continuous without being open.

[0037] Note that in this embodiment, the cutting edge Bm is installed at the tip of the casing 11a at the leading end in the propulsion direction, and the magazine M is mounted within the installed cutting edge Bm, but the cutting edge Bm with the magazine M mounted in advance may be installed at the tip of the casing 11a.

[0038] Now, if the cutting edge Bm with the magazine M mounted is installed at the tip of the casing 11a at the leading end in the propulsion direction in this way, as shown in FIG. 4, the casing 11 is made to enter below the pipe roof 8R, and the casing 11 is installed in the casing installation planned area S. (Third step) 。

[0039] Note that the casing 11 is a structure for constructing a tunnel such as an underpass, and has a hollow structure. As shown in FIG. 6, the casing 11 is composed of an upper slab 11-1 and a lower slab 11-2 that face each other in the vertical (height) direction, and wall plates 11-3 that face each other in the horizontal direction at both ends and intermediate positions thereof. Further, the front and rear are open as openings. The casing 11 of the present embodiment is constructed by arranging a plurality of pieces (casing 11) in the axial direction with the openings communicating with each other. Further, through holes (not shown) through which PC steel wires are inserted are formed in the casing 11 along the longitudinal direction of the pipe 8 (that is, the propulsion direction of the casing 11).

[0040] In this Third step case, first, a sheet-like member Sh is pulled out from the magazine M by a predetermined length, and one end (one end) thereof is fixed to the starting side end of the casing installation planned area S. Then, while cutting the ground with the cutting edge Bm installed on the casing 11a at the leading end in the propulsion direction, the casing 11 is propelled under the pipe roof 8R, and the casing 11 is installed in the casing installation planned area S.

[0041] In FIG. 4, when the casing 11 is entered and installed, a plurality of casings 11 are penetrated from the starting shaft 2 on the starting side (here, the shaft 2 on the right side in FIG. 4) and connected by PC steel wires, and a middle push jack J1 is installed between the casings 11, and an ESA jack (not shown), which is a center hole type hydraulic jack, is installed at the rearmost part. Note that the tip of the PC steel wire (the tip in the propulsion direction of the casing 11) is fixed to the leading casing 11, and the rear end is attached to the rearmost ESA jack. In the present embodiment, four pieces of casings 11a, 11b, 11c, and 11d are shown, but three or more pieces may be used.

[0042] Further, a through hole (guide adit) is provided in the ground E within the installation range of the casing 11 from the shaft 2 on the arrival side (here, the shaft 2 on the left side in FIG. 4), the PC steel wire is inserted therethrough, one end is fixed to the leading casing 11a, and the other end is connected to a traction jack J2 provided in the shaft 2 on the arrival side for traction of the casing 11.

[0043] With such a configuration, when propelling one casing 11, the frictional resistance due to the earth pressure and self-weight of the other multiple casings 11 is used as a reaction resistance body. Specifically, when propelling the four-piece casings 11a to 11d as in the present embodiment, first, the leading casing 11a is advanced by the internal pushing jack J1 installed at the tail of the casing 11a. At this time, the traction jack J2 described above is also used to traction the casing 11a, and the casing 11a is held at the position where it can advance to prevent backward movement due to earth pressure. Next, the internal pushing jack J1 that advanced the leading casing 11a is retracted, and the casing 11b is advanced by the internal pushing jack J1 installed at the tail of the casing 11b. Next, the internal pushing jack J1 that advanced the casing 11b is retracted, and the casing 11c is advanced by the internal pushing jack J1 installed at the tail of the casing 11c. Finally, the internal pushing jack J1 that advanced the casing 11c is retracted, and the rearmost casing 11d is advanced by the ESA jack installed at the rearmost with the casings 11a to 11c connected by PC steel wires as a reaction force. In this way, starting from the leading casing 11a, the subsequent casings 11b, 11c, and 11d are sequentially propelled one by one, and the casing 11 is installed below the pipe roof 8R (see Fig. 6).

[0044] Here, as described above, since the end of the sheet-like member Sh stored in the magazine M is fixed to the starting side end of the casing installation planned area S, as shown in Fig. 5, the sheet-like member Sh wound in a roll shape is pulled out from the magazine M and extended as the casing 11 is propelled, and is installed along the outer surface of the casing 11 (the upper surface and both side surfaces of the casing 11).

[0045] That is, although the casing 11 advances, the sheet-like member Sh remains at the position pulled out from the magazine M, so the edge between the natural ground E and the outer surface of the casing 11 is blocked by the sheet-like member Sh, and the soil of the natural ground E is not dragged by the advancement of the casing 11.

[0046] Furthermore, as described above, the contact surface of the sheet-like member Sh in the present embodiment with the outer surface of the casing 11 is subjected to a friction reduction treatment in which a lubricant is coated. Therefore, the advancing casing 11 slides more easily on the sheet-like member Sh, so the frictional force during casing propulsion becomes smaller, and the casing 11 can be propelled with a smaller force.

[0047] Here, when the casing 11 is propelled, as shown in FIG. 5, rigid urethane foam UF is injected from the injection hole 8a formed in the pipe 8 between the pipe loop 8R and the sheet-like member Sh installed on the outer surface of the casing 11. In the present embodiment, an operator is inside the pipe 8, and when the operator confirms that the leading casing 11a during entry has reached the injection hole 8a formed in the pipe 8, rigid urethane foam UF is manually injected from the confirmed injection hole 8a between the pipe loop 8R and the sheet-like member Sh. The reason for injecting the rigid urethane foam UF is as follows.

[0048] That is, below the constructed pipe loop 8R, there is unexcavated natural ground E that supports the pipe loop 8R. However, as the casing 11 enters, the natural ground E may be carried in the entry direction due to friction with the casing 11 and the cutting edge Bm, or may collapse from the tip of the cutting edge Bm and soil may flow into the casing 11 through the opening on the front side of the casing 11, resulting in partial loss. In particular, when the natural ground E is soft, even when the above-described sheet-like member Sh is used, such loss is likely to occur. Furthermore, when the natural ground E is strengthened by ground improvement to ensure the support of the pipe loop 8R, the chemicals for ground improvement remaining in the natural ground E may adhere to the surface of the casing 11, or the strengthened natural ground E may be carried as a whole in the entry direction, resulting in an increase in loss.

[0049] At this time, as described above, by injecting the rigid urethane foam UF between the pipe loop 8R and the sheet-like member Sh, the rigid urethane foam UF penetrates into the natural ground E and hardens, so that the natural ground E can be strengthened and the loosening of the natural ground E can be prevented.

[0050] In addition, since the sheet-like member Sh installed along the outer surface of the casing 11 remains at the position pulled out from the magazine M and does not move, the rigid urethane foam UF located between such a sheet-like member Sh and the pipe roof 8R cannot be dragged by the forward movement of the casing 11 and can surely penetrate into the natural ground E.

[0051] Furthermore, since the outer surface of the casing 11 is covered with the sheet-like member Sh, the sheet-like member Sh can protect the rigid urethane foam UF from adhering to the outer surface of the casing 11.

[0052] Note that the injection timing of the rigid urethane foam UF is not limited to when or after the leading casing 11a reaches the injection hole 8a formed in the pipe 8, and can be freely determined. Also, the injection of the rigid urethane foam UF does not have to be performed by an operator. For example, while checking the positional relationship between the injection hole 8a and the casing 11 with a camera, a tube may be inserted into the pipe 8 for injection. When checking the position of the casing 11 with an operator or a camera, it is not necessary to check all the casings 11, and the rigid urethane foam UF may be injected from all the pipes 8 at the timing when the position can be confirmed from a specific pipe 8. Also, it is not necessary to provide injection holes 8a in all the pipes 8, and pipes 8 provided with injection holes 8a at every few intervals may be installed according to the filling property of the rigid urethane foam UF.

[0053] As the rigid urethane foam UF, in this embodiment, for example, Setform (registered trademark of Nisshinbo Chemical Inc.) is used. This rigid urethane foam UF starts foaming 12 seconds after injection, has a short curing time of about 1 minute, and reaches the final strength (about 1 N / mm 2 level) in about 30 minutes. However, the type of the rigid urethane foam UF used is not particularly limited.

[0054] Here, as described above, the arrangement shape of the pipe roof 8R of the present embodiment is in a portal shape, and a plurality of pipes 8 are installed adjacent to each other along the upper side and the outer sides of both sides of the planned installation area S of the casing. In such a portal-shaped pipe roof 8R, rigid urethane foam UF may be injected only between the pipe roof 8R of the portion located above the casing 11 and the upper surface of the casing 11, and the pipe roof 8R may be supported on the upper surface of the casing 11 into which the rigid urethane foam UF has been injected. Also, as shown in FIG. 6, rigid urethane foam UF may be injected between both sides of the pipe roof 8R and the side surface of the casing 11, and the earth pressure applied to the side of the pipe roof 8R may be supported by the side surface of the casing 11.

[0055] 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 changes that are equivalent to the technology described in the claims and that do not depart from the gist of the claims are included.

[0056] For example, in the present embodiment, a friction reduction treatment in which a lubricant is coated is performed on the contact surface of the sheet-like member Sh with the outer surface of the casing 11. However, the friction reduction treatment is not limited to such coating. For example, a lubricant impregnated member (a member impregnated with a lubricant) is installed in the magazine M so as to contact the contact surface of the sheet-like member Sh with the outer surface of the casing 11, and when the sheet-like member Sh is pulled out from the magazine M, a lubricant may be applied to the contact surface of the sheet-like member with the outer surface of the casing 11.

[0057] Also, in this embodiment, rigid urethane foam UF is injected between the pipe roof 8R and the sheet-like member Sh, but the injection of this rigid urethane foam UF is not essential. That is, since the soil of the natural ground E is not dragged by the sheet-like member Sh, when the natural ground E supporting the pipe roof 8R does not suffer damage due to the entry of the casing 11, or only suffers minor damage that can be ignored, the injection of rigid urethane foam UF may not be performed. Note that when the rigid urethane foam UF is not injected, the injection hole 8a of the pipe 8 is unnecessary.

[0058] Also, in this embodiment, a construction method combining the FJ method and the ESA method is used, but it is not limited to this. Any underpass construction method using the pipe roof 8R (a method of constructing a tunnel by pushing the casing 11 under the pipe roof 8R) may be used, such as the FJ method or the ESA method used alone, or a method of providing a reaction wall on the launching shaft side and using the reaction wall to take reaction force to push the casing 11.

[0059] Furthermore, in this embodiment, the pipe 8 is press-fitted into the natural ground E so that the injection hole 8a faces the casing installation planned area S side, but the injection hole 8a does not necessarily have to be in a position strictly facing the casing 11. As long as the injection hole 8a faces a position where the rigid urethane foam UF is injected between the pipe roof 8R and the casing 11.

Industrial Applicability

[0060] In the above description, the case where the present invention is applied to the installation method of a casing for forming an underground pedestrian crossing has been described. However, for example, it can also be applied to the installation methods of casings for other uses such as sewers, water conduits, or road culverts.

Explanation of Reference Numerals

[0061] 1 Temporary earth retaining pile 2 Shaft 8 Pipe (steel pipe) 8a Injection hole 8R Pipe roof 11, 11a, 11b, 11c, 11d Body Bm Cutting Edge E Ground Mountain J1 Middle Pushing Jack J2 Towing Jack M Magazine (Case Body) S Scheduled Installation Area of the Body Sh Sheet-like Member UF Rigid Foamed Urethane

Claims

Claim 1. A method for installing a casing by propelling the casing under a pipe roof and installing it in a planned installation area of the casing, comprising: a first step of inserting a plurality of steel pipes having injection holes formed at predetermined intervals along the axial direction into the ground so as to be adjacent to each other with the injection holes facing the planned installation area side of the casing, and constructing a pipe roof for protecting the casing to be installed; a second step of installing a blade edge at the tip of the casing at the leading end in the propulsion direction, and further mounting a case body in which a sheet-like member wound in a roll shape and capable of being pulled out is stored within the blade edge; a third step of fixing one end of the sheet-like member to the starting side end of the planned installation area of the casing, propelling the casing under the pipe roof, cutting the ground with the blade edge, and installing the casing in the planned installation area of the casing while installing the sheet-like member pulled out from the case body along the outer surface of the casing; characterized by comprising: in the third step: when the leading casing entering reaches each injection hole formed in the steel pipe, injecting rigid urethane foam between the pipe roof and the sheet-like member installed along the outer surface of the casing from the injection hole; A method for installing a casing, characterized by the above. Claim 2. On the contact surface of the sheet-like member with the outer surface of the casing, a friction reduction treatment for reducing friction with the propelled casing is performed. The method for installing a casing according to claim 1, characterized by the above. Claim 3. The friction reduction treatment of the sheet-like member is: a treatment of pre-coating a lubricant on the contact surface, or a treatment of applying a lubricant with a lubricant-impregnated member to the contact surface of the sheet-like member when it is pulled out from the case body. The method for installing a casing according to claim 2, characterized by the above. Claim 4. The pipe roof is a single-row type in which a plurality of steel pipes are inserted into the ground so as to be adjacent to each other above the planned installation area of the casing, or a portal type in which a plurality of steel pipes are inserted into the ground so as to be adjacent to each other above and on both outer sides of the planned installation area of the casing, and the rigid urethane foam is injected between the pipe roof at least at the portion located above the casing and the sheet-like member installed along the upper surface of the casing. The method for installing a casing according to claim 3, characterized by the above. In the third step: The method of installing the casing is to install it under the pipe roof by a method of entering the casing while excavating the front ground from the opening on the advancing direction side. The method for installing a casing according to any one of claims 1 to 4, characterized by the above.

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