JP2020063640A - Spacer and propulsion method for box structure - Google Patents

Abstract

To efficiently install a spacer used for propelling a box structure without removing a girder material.SOLUTION: In a spacer 32 used in a box propulsion method in which a plurality of box-shaped roofs 23 on which FC plates 26 fixed by a fixing member 40 are mounted are installed in a starting shaft 21 so that the planned construction positions of a hollow box structure 10 having a rectangular cross section and the outer surface are flush and aligned, and the box body structure 10 is constructed under the route and across it by propelling the box body structure 10, the fixing member 40 comprises a rectangular frame body to which the FC plate 26 is fixed on one side, and a girder member 45 arranged along the propelling direction of the box structure 10 inside the frame body, and the spacer 32 is divided into a plurality of spacer pieces 32a and 32b which are divided so as to be able to pass through the frame body without interfering with the girder member 45 and which are installed in parallel to each other in the propelling direction of the box structure 10.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a spacer and a method for propelling a box structure.

  In order to construct a hollow box structure having a rectangular cross section (for example, a precast box culvert etc.) under a route without hindering the flow of a running train or car, the box propulsion method (for example, R & C method, SFT method, etc.) is used.

  In this box propulsion method, a plurality of box-shaped roofs with hollow rectangular cross-sections are arranged along the line crossing direction so that the planned construction position of the box structure and the outer surface are aligned. Press in. Then, using a propulsion jack, while appropriately sandwiching a spacer between the propulsion jack and the box structure, the box structure is propelled and the box-shaped roof is pushed from the starting vertical shaft side to the reaching vertical shaft side, Will be replaced with a box-shaped roof to build under the line.

  A technique for installing a box structure is described in, for example, Japanese Patent Publication No. 63-31623.

Japanese Examined Patent Publication No. 63-31623

  In the box body propulsion method, FC (Friction Cut) plates are installed on the upper surface of the assembled box-shaped roofs to cut the edges from the surrounding ground during the propulsion construction of the box body structure, and the friction resistance during propulsion. This prevents turbulence and tailgating (a phenomenon in which the embankment on top of the box structure moves to the reaching shaft while riding on the box structure).

  The FC plate fixes the FC plate by a predetermined fixing method on the side of the starting shaft, and the tensile force generated by the friction between the box structure and the FC plate generated when the box structure is propelled (along with the box structure in the propelling direction). Force to go).

  Here, the tie rod type is known as one of the fixing methods for the FC plate. In the tie rod method, one side is fixed to the FC plate, and one side opposite to it is fixed inside the frame that is fixed to the bearing wall on the back of the shaft, and is made of steel such as PC steel rod along the propelling direction of the box structure. The movement of the FC plate is regulated by the fixing member on which the girder material is arranged.

  However, the tie rod type fixing method has the following problems. That is, in order to reduce the number of times the box structure is installed, a plurality of box structures are installed in the starting shaft at a time, and these box structures are propelled for a predetermined length and spacers are installed. , Promote the box structure. At this time, since the cross-sectional area of the spacer is substantially the same as the cross-sectional area of the box structure, when the spacer is installed, the above-mentioned girder material is once removed, the spacer is installed, and then the spacer is installed again. In other words, it is necessary to remove and re-install the girder material every time the spacer is installed.

  The present invention has been made from the above technical background, and an object thereof is to provide a technique capable of efficiently installing a spacer used for propelling a box structure without removing the girder material. And

  In order to solve the above problems, the spacer of the present invention according to claim 1 is fixed by a fixing member such that the planned construction position of the hollow box structure having a rectangular cross section and the outer surface are aligned and aligned. A plurality of box-shaped roofs on which FC plates are mounted are installed in a starting shaft, and used for a box body propulsion method in which the box body structure is constructed by traversing the box body structure under a route. The fixing member is composed of a rectangular frame body having the FC plate fixed to one side, and a girder member arranged inside the frame body along the propelling direction of the box structure. The spacer is composed of a plurality of spacer pieces which are divided so as to be able to pass through the frame without interfering with the girder material and which are installed in parallel to each other in the propelling direction of the box structure. It has been characterized.

  In order to solve the above problems, the method for propelling a box structure of the present invention according to claim 2 traverses the box structure under a route by propelling a hollow box structure having a rectangular cross section. A method of propelling a box structure in a box propulsion method, wherein a plurality of box-shaped FC plates are mounted so that the planned construction position of the box structure and the outer surface are aligned and aligned. Installation of the roof on the starting shaft, fixing of a rectangular frame body having the FC plate fixed to one side, and a girder material arranged inside the frame body along the propelling direction of the box structure A step of constructing a member and a plurality of spacer pieces that are divided so as to be able to pass through the frame without interfering with the girder member and that are arranged in parallel to each other in the propelling direction of the box structure. Preparing the spacer, and the starting shaft A step of installing the box structure, propelling the box structure using the spacer, and installing the box structure under a line while repeating the work of removing the spacer; It is characterized by having.

  According to a third aspect of the present invention, there is provided a method for propelling a box structure according to the second aspect, wherein in the step of preparing the spacer, a plurality of spacers are prepared in advance. In the step of installing the structure across the line, a plurality of the box structures are installed in the starting shaft, and one spacer is provided each time the plurality of box structures are propelled for a predetermined length. It is characterized by being installed.

  A method for propelling a box structure according to a fourth aspect of the present invention is the method according to the second or third aspect, wherein both ends of the girder member are detachably fastened to the frame body, The box structure is characterized in that the girder material is removed and installed in the starting shaft.

  The box structure propelling method of the present invention according to claim 5 is the invention according to any one of the above claims 2 to 4, wherein the girder material is made of shaped steel or steel bar. It is characterized by

  According to the present invention, the spacer is divided so that it can pass through the frame body without interfering with the girder member, and is composed of a plurality of spacer pieces arranged in parallel to each other in the propelling direction of the box structure. Therefore, the work of installing the spacer after propelling the box structure for a predetermined length can be performed without removing the girder material. This allows the spacers to be installed efficiently.

It is a perspective view showing a box structure used in a method for propelling a box structure according to an embodiment of the present invention. It is explanatory drawing which shows a part of process in R & C construction method which is one of the propulsion construction methods performed by the propulsion method of the box structure which concerns on one embodiment of this invention. It is explanatory drawing which shows the process following FIG. 2 in the R & C construction method which is one of the propulsion construction methods performed by the propulsion method of the box structure which concerns on one embodiment of this invention. It is explanatory drawing which shows the process following FIG. 3 in the R & C construction method which is one of the propulsion construction methods performed by the propulsion method of the box structure which concerns on one embodiment of this invention. It is explanatory drawing which shows the process following FIG. 4 in the R & C construction method which is one of the propulsion construction methods performed by the propulsion method of the box structure which concerns on one embodiment of this invention. It is a top view which shows the starting shaft in which the fixing member of the FC plate which is one embodiment of this invention was constructed. It is a top view showing the state where three box structures were installed in the starting shaft in which the fixing member of the FC plate which is one embodiment of the present invention was built. It is a top view which shows the state which is propelling the box structure installed in the starting shaft in which the fixing member of the FC plate which is one embodiment of the present invention is propelled by the propelling jack and the spacer. It is a front view which shows the starting shaft entrance of the starting shaft of FIG. FIG. 7 is a cross-sectional view taken along the line AA of FIG. 6. It is sectional drawing which followed the BB line | wire of FIG. It is a front view which shows the 1st frame material and the 2nd frame material which comprise the fixing member of FC plate. It is a perspective view which shows the fastening structure of a girder material, a 1st frame material, and a 2nd frame material. FIG. 14 is a plan view of FIG. 13. It is sectional drawing which followed CC line of FIG. It is sectional drawing which shows the edge part of a beam material. It is sectional drawing which shows the fastening plate fixed to the 1st frame material and the 2nd frame material. It is a top view which shows the corner part of the frame which comprises the fixing member of FC plate.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. In addition, in the drawings for describing the embodiments, the same components are denoted by the same reference symbols in principle and the repeated description thereof will be omitted.

  The box structure used in the present embodiment is, for example, a PRC (Prestressed Reinforced Concrete) structure in which prestress is introduced into the upper and lower slabs, and has a hollow structure having a rectangular cross section as shown in FIG. 1. By constructing an underground structure by arranging such a box structure in cascade, it is used as a culvert for roads, a sewer, a headrace, an underground pedestrian crossing, or the like.

  In FIG. 1, a box structure 10 is composed of an upper slab 10a and a lower slab 10b that face each other in the vertical direction, and a pair of side plates 10c and 10d that laterally face each other at both ends of the upper slab 10a and the lower slab 10b. . The front and rear are opened as openings 10e. Then, an underground structure is constructed by arranging a plurality of box structures 10 in a row by propelling them while communicating the openings 10e with each other.

  As shown in the figure, at four corners of the box structure 10, fixing material insertion holes 10f extending along the propelling direction for fixing adjacent box structures 10 to each other with bolts and nuts are formed. ing. Although not formed in the illustrated box structure 10, for example, the box structures 10 arranged every three bodies are provided with grout holes for injecting grout material after installation. Has been formed.

  Next, the construction of an underground structure using such a box structure 10 will be described with reference to FIGS. In addition, the construction of the underpass that crosses under the orbit will be described here. Further, in this embodiment, the R & C method, which is one of the propulsion methods, is used.

  The underpass is provided below the track 20 and intersects with the track 20. In order to construct such an underpass, as shown in FIG. 2, first, the earth retaining walls 25 are driven into both sides of the track 20 to excavate the starting shaft 21 and the reaching shaft 22, and then the planned position of the planned underground road. A box-shaped roof 23 having a hollow rectangular cross section is press-fitted in a direction traversing the track 20 from the starting shaft 21, that is, in the extending direction of the underpass. The press fitting is performed by using the propulsion device 24.

  The box-shaped roof 23 is press-fitted so that the planned position of the upper slab 10a of the box structure 10 is aligned with the outer surface. Further, the outer surfaces of the side structures 10c and 10d of the box structure 10 are also arranged so that their outer surfaces are aligned with each other. In many cases, a plurality of box structures 10 are arranged in tandem, so that the number of box-shaped roofs 23 is also arranged in tandem according to the number of box structures 10, but in FIGS. , 6 bodies are arranged in tandem. In addition, in these drawings, in order to avoid complication of drawing display, the illustration of the box-shaped roof 23 press-fitted into the positions where the side plates 10c and 10d of the box structure 10 are to be arranged is omitted.

  At this time, an excavator (not shown) such as an auger is inserted into the box-shaped roof 23 to excavate the ground below the surface of the track 20 while pushing the rear end of the box-shaped roof 23 with the propulsion unit 24. Press-fit until reaching the reaching shaft 22. At this time, the excavated soil is carried out from the rear through the inside of the box-shaped roof 23 by the auger screw.

  Here, the FC plate 26 is placed on the upper surface of the box-shaped roof 23 that is press-fitted into the upper slab 10a of the box structure 10, and only the tip of the FC plate 26 is attached to the tip of the box-shaped roof 23. Secure by welding or screwing. After the box-shaped roof 23 is press-fitted, the fixation with the box-shaped roof 23 is released, and the box-shaped roof 23 is fixed to the fixing member 40 of the FC plate 26 described later.

  In such work, when the box-shaped roof 23 is propelled and replaced with the box structure 10, the FC plate 26 causes the disturbance of ground and tailgating due to frictional resistance generated between the box-shaped roof 23 and the ground. This is to prevent this.

  After the press-fitting of the box-shaped roof 23 penetrating from the starting shaft 21 to the reaching shaft 22 is completed in this way, as shown in FIG. 3, the propulsion base 27 is installed in the starting shaft 21 and the fixing member 40 is constructed. Then, the FC plate 26 is fixed, and the box structure 10 in which the blade 28 is attached to the box-shaped roof 23 is mounted on the propulsion base 27 (in the present embodiment, three box bodies at a time are used). (Structure 10) is installed. In addition, a pedestal 29 for receiving the box-shaped roof 23 that is replaced with the box structure 10 and is removed is installed in the reaching shaft 22.

  Further, the blade opening 28 is for cutting the ground where the box-shaped roof 23 is not press-fitted, and by being pressed from the rear side, the inside of the ground is press-fitted and cut so that the cut earth and sand are taken into the inside of the blade opening 28. The front is inclined inward.

  As described above, in the present embodiment, the box body structure 10 is installed after the fixing member 40 of the FC plate 26 is constructed. The specific content of the fixing member 40 will be described later.

  If the box structure 10 is placed on the propulsion table 27 as described above, the pressure bearing wall 31 is provided between the rear end surface of the box structure 10 and the rear end wall surface of the starting shaft 21. A plurality of propulsion jacks 30 are installed so as to exert a reaction force on the bearing wall 31.

  Then, the spacer 32 is prepared in advance, and as shown in FIG. 4, the propelling jack 30 is operated and one spacer 32 is installed every time the propelling jack 30 is propelled by the length of one box structure 10. Meanwhile, when the box structure 10 is propelled while excavating the ground with the blade mouth 28, the box-shaped roof 23 is pushed toward the reaching shaft 22 side. Along with this, the ground on both side walls of the box structure 10 is cut by the blade 28, and the earth and sand are taken into the box structure 10. Therefore, the propulsion jack 30 further removes this earth and sand to further form the box structure. The object 10 is pressed.

  At this time, since the FC plate 26 is fixed to the fixing member 40, the earth and sand in the surface layer portion does not move even though the box-shaped roof 23 moves to the reaching shaft 22 side.

  In this way, the three box structures 10 initially installed are propelled along the FC plate 26, and the top box-shaped roof 23 is discharged to the reaching shaft 22 side while cutting the internal sediment, and the box structure is formed. If the object 10 is replaced, as shown in FIG. 5, the spacer 32 (in the present embodiment, since the three box structures 10 have been propelled, the three spacers 32) is removed and the process proceeds. The following three body structures 10 are installed behind the three body structures 10.

  Then, in the same manner as the case of the first three box structures 10, these box structures are installed while one spacer 32 is installed each time the box structure 10 is propelled by the length of one box structure 10. The object 10 is propelled and the next box-shaped roof 23 is discharged to the reaching shaft 22 side. If the box structures 10 are arranged in tandem by repeating this in sequence, an underpass is constructed.

  In the present embodiment, when the length of the box structure 10 is 1 m, first the spacer 32 is installed if the box structure 10 is propelled by 0.7 m. Then, if it is promoted by 1 m, the next spacer 32 is installed, and if it is further promoted by 1 m, the next spacer 32 is installed. Then, if further propelled by 0.3 m, the three spacers 32 are removed, the next three box structures 10 are installed, and this is repeated thereafter.

  However, such a propelling pattern of the box structure 10 is an example, and the present invention is not limited to this. For example, if one box structure 10 is propelled by one spacer 32, the spacer 32 may be removed and the next one box structure 10 may be installed. .

  In the above description, the case where the box structure 10 is pressed from the rear end side has been described, but a method such as burying a steel wire from the reaching shaft side and pulling the box structure 10 may be adopted. Well, in short, the box structure 10 may be propelled.

  Next, the structure of the fixing member 40 fixing the FC plate 26 and the propulsion of the box structure in the embodiment of the present invention will be described with reference to FIGS. 6 to 12.

  FIG. 6 is a plan view showing a starting shaft in which an FC plate fixing member according to an embodiment of the present invention is constructed, and FIG. 7 is a starting state in which an FC plate fixing member according to an embodiment of the present invention is constructed. FIG. 8 is a plan view showing a state in which three box structures are installed in the shaft, and FIG. 8 is a box structure installed in the starting shaft in which the fixing member of the FC plate according to the embodiment of the present invention is constructed. FIG. 9 is a plan view showing a state in which the vehicle is propelled by a propelling jack and a spacer, FIG. 9 is a front view showing a starting hole of a starting shaft of FIG. 6, and FIG. 10 is a sectional view taken along line AA of FIG. 6 is a cross-sectional view taken along the line BB of FIG. 6, and FIG. 12 is a front view showing a first frame member and a second frame member that form a fixing member of the FC plate.

  As shown in FIGS. 6 to 11 and as described above, a plurality of box-shaped roofs 23 are press-fitted from the starting shaft 21 to the reaching shaft 22 so that the planned position of the box structure 10 and the outer surface are aligned and aligned. ing.

  As shown in FIG. 7, in the starting shaft 21, three box structures 10 are installed on the propulsion table 27 at one time. However, the number of the box structures 10 installed at one time is not limited to three, and it is optimal depending on various conditions such as the size of the box structure 10, the situation of the site, and the capability of the propulsion jack 30. The number of installations is decided. Then, as described above, the propulsion jack 30 is operated to repeatedly propel the box structure 10 and install the spacers 32, and the box structures 10 are arranged in tandem to construct an underpass.

  As shown in FIGS. 6 to 8, on the upper surface of the box-shaped roof 23, an FC plate 26 made of a strip-shaped steel plate having a width and a length substantially equal to that of the box-shaped roof 23 is placed. As shown in FIG. 9, since there are a plurality of box-shaped roofs 23 corresponding to the upper slab 10a of the box structure 10, a plurality of FC plates 26 also correspond to these box-shaped roofs 23 (in this embodiment). 6 sheets are installed in the form).

  Now, as shown in these drawings, the fixing member 40 for fixing the FC plate 26 is made of a steel material such as H-shaped steel, and a first frame member 41 forming a rectangular frame body, The second frame member 42, the third frame member 43, and the fourth frame member 44, and the girder member 45 arranged inside the frame body along the propelling direction of the box structure 10. . In addition, in this application, "rectangle" is a concept including not only a rectangle but a square.

  The first frame member 41 is fixed to the FC plate 26, the second frame member 42 facing the first frame member 41 is attached to the bearing wall 31, and the third frame member 43 and the fourth frame member are attached. Both ends of the member 44 are fixed to the end of the first frame member 41 and the end of the second frame member 42, respectively. Further, both ends of the girder member 45 are detachably fastened to the first frame member 41 and the second frame member 42.

  Here, the first frame member 41 is arranged along the arrangement direction of the end portions of the FC plates 26, and is fixed to all the FC plates 26 by welding. Specifically, the plurality of substantially triangular fixing plates 50 are welded to the corners formed by the wall surfaces on both sides of the first frame member 41 and the surface of the FC plate 26, whereby the first frame member 41 and The FC plate 26 is fixed. In addition to the fixed plate 50 or in place of the fixed plate 50, the first frame member 41 and the FC plate 26 may be directly welded.

  Further, as shown in FIG. 12, a plate extending in the longitudinal direction is provided on the first frame member 41 so as to be bridged between a pair of flanges F formed so as to sandwich the web W of H-section steel. -Shaped reinforcing material 51 is welded.

  With such a structure, the FC plate 26, which tends to move to the reaching shaft 22 side together with the box-shaped roof 23 by the propulsion of the box structure 10, is restricted.

  As described above, the second frame member 42 is arranged at a position facing the first frame member 41 and attached to the bearing wall 31. Here, the bearing wall 31 is made of H-shaped steel, which is a steel material arranged side by side in the vertical direction. The second frame member 42 is arranged on the side opposite to the propelling direction of the box structure 10 on the bearing wall 31, and presses the steel material that is the bearing wall 31 when propelling the box structure 10. It is installed so that

  As shown in FIG. 12, the plate-shaped reinforcing member 51 similar to the first frame member 41 is also welded to the second frame member 42. Further, as shown in FIGS. 10 and 11, a reinforcing member 31a is vertically welded to the bearing wall 31 at predetermined intervals so as to be fitted into the H-shaped cross section of the bearing wall 31. With such a reinforcing structure, the force in the propulsion direction transmitted through the FC plate 26 by the propulsion of the box structure 10 is opposed.

  In the present embodiment, a spacer (not shown) is detachably fitted between the second frame member 42 and the bearing wall 31, and the distance between the two is secured, for example, about 10 cm. This is based on the assumption that the fixing member 40 itself is excessively displaced as the box structure 10 is propelled. That is, when an excessive displacement occurs, the pressure support plate of the flat jack is inserted into the gap created by removing the spacer to widen the gap, and the second frame member 42 is pushed back and displaced. It is possible to reduce the amount afterwards.

  The second frame member 42 may be fixed to the bearing wall 31 by welding or bolts. However, as in the present embodiment, if the pressure bearing wall 31 is pushed on the side opposite to the propelling direction of the box body structure 10 so as to press the pressure bearing wall 31 when the box body structure 10 is propelled. Since the work for fixing the second frame member 42 to the bearing wall 31 is unnecessary, the installation and removal of the second frame member 42 are facilitated.

  As shown in FIG. 6, both ends of the third frame member 43 and the fourth frame member 44 are welded to the end of the first frame member 41 and the end of the second frame member 42. The first frame member 41 and the second frame member 42 are fixed by bolts and the like to form a rectangular frame body.

  Further, as shown in the same FIG. 6, in the girder material 45 made of steel material such as H-shaped steel like the rectangular frame body, both ends of the girder material 45 are the central portion of the first frame material 41 and the second frame. It is detachably fastened to the central portion of the material 42. Note that various steel materials such as H-shaped steel, shaped steel such as I-shaped steel, steel bar such as PC steel bar, and steel plate can be applied to the girder material 45.

  As shown in FIG. 8, the spacer 32 is divided into two spacer pieces 32 a and 32 b that can pass through the frame body without interfering with the girder member 45, and are separated from each other with respect to the propelling direction of the box structure 10. It is supposed to be installed in parallel with.

  In the present embodiment, since the spacer 32 is thus divided into the spacer pieces 32a and 32b, the work of installing the spacer 32 after propelling the box structure 10 for a predetermined length removes the girder material 45. Since it can be performed without doing so, the spacer 32 can be installed efficiently.

  Further, since the spacer 32 is divided into the spacer pieces 32a and 32b to reduce the weight, it is possible to reduce the labor of the operator when installing the spacer 32.

  The spacer 32 only needs to be able to pass through the frame body without interfering with the girder member 45, and may be divided into three or more, instead of being divided into two as in the present embodiment.

  Here, the fastening structure of the girder member 45 and the first frame member 41 and the second frame member 42 will be described with reference to FIGS. 13 to 17.

  13 is a perspective view showing the fastening structure of the girder member and the first frame member and the second frame member, FIG. 14 is a plan view of FIG. 13, FIG. 15 is a sectional view taken along line CC of FIG. FIG. 16 is a cross-sectional view showing the end portion of the girder material, and FIG. 17 is a cross-sectional view showing the fastening plate fixed to the first frame material and the second frame material.

  As shown in FIGS. 13 to 15, a cutout is formed by removing the web W at the end of the girder member 45, and one fastening plate 45a is provided at that portion. The fastening plate 45a is made of steel and is fixed in the vertical direction so as to sandwich the web W therebetween. Further, in the central portions of the first frame member 41 and the second frame member 42, three fastening plates 55 made of steel material extending in a direction orthogonal to the longitudinal direction of these girder members 41, 42 are provided. It is fixed vertically with a space between.

  Here, as shown in FIG. 16, the fastening plate 45a of the girder member 45 is fixed to approximately the center of two flanges F that are parallel to each other. In addition, as shown in FIG. 17, of the three fastening plates 55 fixed to the first frame member 41 and the second frame member 42, the two outer fastening plates 55 fix the girder member 45 from both sides. The inner fastening plates 55 are fixed at positions that are slightly laterally displaced from the centers of the two outer fastening plates 55 at such intervals that they can be sandwiched.

  As a result, as shown in FIGS. 13 to 15, the ends of the girder members 45 are in surface contact with each other while being fitted into the fastening plates 55 fixed to the first frame member 41 and the second frame member 42. .

  As shown in these drawings, the fastening plates 55 and the girder members 45 fixed to the first frame member 41 and the second frame member 42 are formed with through holes H that are located in a straight line with each other. There is. A wedge material (fastening member) 56 is detachably inserted into the through holes H so as to penetrate the through holes H.

  As shown in FIG. 13, the wedge material 56 is composed of a pair of layers which are opposite to each other and overlap each other. That is, by inserting one wedge material 56 from one side into the through hole H and then inserting the other wedge material 56 from the opposite side, the wedge material 56 can be inserted into the through hole H without a gap. ing.

  Then, with such a fastening structure, the first frame member 41 and the girder member 45 are fastened, and the second frame member 42 and the girder member 45 are fastened.

  A fluororesin-processed sheet is attached to the contact surface between the wedge material 56 and the wedge material 56. As a result, the frictional resistance between the wedge members 56 when the wedge member 56 is inserted into or removed from the through hole H is reduced, and the wedge member 56 can be inserted and removed smoothly.

  The wedge material 56 may be a plurality of pairs instead of one pair. Further, the fastening member inserted in the through hole H is not limited to the wedge material 56, and may be, for example, a pin or a bolt. However, when the pin is used, it is necessary to make the diameter of the through hole H slightly larger than the outer diameter of the pin, and the displacement of the fixing member 40 is allowed by the play allowance. Further, when bolts are used, the number of bolts increases with respect to the acting axial force. On the other hand, the wedge material 56 is preferable because these problems do not occur.

  As shown in FIG. 6, the corners formed by the first to fourth frame members 41 to 44 and the outer fastening plate 55 fixed to the first frame member 41 and the second frame member 42 are The reinforcing material 52 for increasing the fixing strength is welded. FIG. 18 shows a reinforcing member 52 provided at a corner formed by the first frame member 41 and the third frame member 43. In the illustrated case, the reinforcing member 52 has a substantially triangular shape, but the shape including the fixing plate 50 described above can be freely set.

  The fixing member 40 of the present embodiment described above includes first to fourth frame members 41 to 44 that are steel members forming a rectangular frame body, and a girder member 45 that is a steel member located inside the frame member. Since it is composed of, it has extremely high rigidity.

  Therefore, with respect to the force generated by the FC plate 26 that moves toward the reaching shaft 22 side together with the box-shaped roof 23 by the promotion of the box structure 10, the first frame member 41 with the FC plate 26 fixed, Third and fourth frame members 43, 44 and girder members 45 pulled in the longitudinal direction by the first frame member 41, and second frame members 42 dispersed by these in three positions and pulled in the lateral direction. By this, it becomes possible to reliably oppose.

  Since the fixing member 40 is composed of the first to fourth frame members 41 to 44, which are steel members forming the rectangular frame body, and the girder member 45, which is the steel member positioned inside the frame body. Therefore, the installation of the fixing member 40 is not restricted by the condition of the surrounding ground. Further, since the space larger than the rectangular frame is not required when constructing the fixing member 40, the fixing member 40 having high rigidity can be constructed even in the narrow starting shaft 21, resulting in excellent space efficiency.

  Here, in the fixing member 40 of the present embodiment, the girder member 45 is detachably fastened to the first frame member 41 and the second frame member 42. Therefore, the process after press-fitting the box-shaped roof 23 is as follows.

  That is, after the box-shaped roof 23 is press-fitted, the fixing member 40 of the portion excluding the girder member 45 is built, and the FC plate 26 is released from the fixing to the box-shaped roof 23 and fixed to the first frame member 41. To do. Then, after the precast box structure 10 is installed in the starting shaft 21 (in the present embodiment, three bodies are installed), the girder material 45 is attached to the first frame material 41 and the first frame material 41 using the wedge material 56. It is fastened to the second frame member 42. After that, the propelling jack 30 is operated to propel the box structure 10 with one spacer 32 installed every time the propulsion jack 30 is propelled by the length of the box structure 10. While propelling the box structure 10, the girder member 45 located at the center of the fixing member 40 is installed, but as described above, the spacer 32 is divided into two spacer pieces 32a and 32b. Therefore, the installation can be performed without interfering with the girder material 45.

  When the propulsion of the three box structures 10 is completed, the spacer 32 is removed, the wedge material 56 is pulled out, and the girder material 45 is removed, behind the preceding three box structures 10. The following three box structures 10 are installed. Then, similarly to the case of the first three box structures 10, these box structures 10 are propelled while the spacers 32 are appropriately installed, and this is sequentially repeated.

  Although the invention made by the inventor has been specifically described based on the embodiments, the embodiments disclosed in the present specification are exemplifications in all respects, and are limited to the disclosed technology. is not. That is, the technical scope of the present invention should not be limitedly interpreted based on the description of the above-described embodiment, but should be interpreted according to the description of the claims, and All modifications are included without departing from the spirit of the claims and the technology equivalent to the described technology.

  For example, the number of the girder members 45 is one in the present embodiment, but the number of the girder members 45 can be set according to the size of the frame body formed by the first to fourth frame members 41 to 44. It is possible to install two or more pieces, that is, a plurality of pieces.

  In the fastening structure of the first frame member 41 and the second frame member 42 and the girder member 45, the number of the fastening plates 55 fixed to the first frame member 41 and the second frame member 42 is three. There is no need, at least one is sufficient. Further, the fastening plate 45a provided on the girder member 45 may be omitted.

  Furthermore, although both ends of the girder member 45 are detachably fastened to the first frame member 41 and the second frame member 42 constituting the frame body, they may be non-detachable. In this case, since the precast box structure 10 cannot be installed, the box structure 10 installed by cast-in-place in the starting shaft 21 and the divided precast members are assembled and installed. It becomes the box structure 10.

  In the above description, the case where the method for propelling the box structure according to the present invention is used for the R & C method, which is one of the propulsion methods, but other than the R & C method, for example, the SFT method or the FJ method. It can be used for various propulsion methods.

10 Box Structure 10a Upper Slab 10b Lower Slab 10c, 10d Side Plate 10e Opening 10f Fixing Material Insertion Hole 20 Orbit 21 Starting Vertical Shaft 22 Reaching Vertical Shaft 23 Box Roof 24 Propulsion Machine 25 Earth retaining Wall 26 FC Plate 27 Propulsion Stand 28 Blade 29 Cradle 30 Propulsion jack 31 Bearing wall 31a Reinforcing plate 32 Spacers 32a, 32b Spacer piece 40 Fixing member 41 First frame member 42 Second frame member 43 Third frame member 43 Fourth frame member 45 Girder member 45a Fastening plate 50 Fixed plate 51 Reinforcement plate 52 Reinforcement plate 55 Fastening plate 56 Wedge material F Flange H Through hole W Web

Claims (5)

A plurality of box-shaped roofs on which FC plates fixed by fixing members are mounted are installed in the starting shaft so that the planned construction positions of the hollow box structure having a rectangular cross section are aligned with the outer surface. A spacer used in a box propulsion method for constructing the box structure by traversing the box structure under a line by propelling the box structure,
The fixing member is composed of a rectangular frame body to which the FC plate is fixed on one side, and a girder member arranged along the propelling direction of the box structure inside the frame body,
The spacer is divided so as to be able to pass through the frame body without interfering with the girder member, and is composed of a plurality of spacer pieces arranged in parallel to each other in the propelling direction of the box structure.
A spacer characterized in that. A method for propelling a box structure in a box propulsion method of constructing the box structure by traversing the box structure under a route by propelling a hollow box structure having a rectangular cross section,
A step of installing a plurality of box-shaped roofs on which FC plates are mounted in a starting shaft so that the planned construction positions of the box structure and the outer surface are aligned and aligned;
A step of constructing a rectangular frame body having the FC plate fixed to one side, and a fixing member made of a girder material arranged inside the frame body along the propelling direction of the box structure;
There is prepared a spacer composed of a plurality of spacer pieces that are divided so as to be able to pass through the frame without interfering with the girder material and that are arranged in parallel to each other in the propelling direction of the box structure. Process,
The box structure is installed on the starting shaft, the box structure is propelled by using the spacer, and the spacer structure is repeatedly removed to install the box structure across the line. And the process of
A method for propelling a box structure, comprising: In the step of preparing the spacer, a plurality of spacers are prepared,
In the step of installing the box structure across the line, a plurality of the box structures are installed in the starting shaft, and the spacers are installed each time the box structures are propelled for a predetermined length. One by one,
The method for propelling a box structure according to claim 2, wherein. Both ends of the girder member are detachably fastened to the frame body,
The box structure is installed in the starting shaft by removing the girder material,
The method for propelling a box structure according to claim 2 or 3, characterized in that. The girder material is composed of shaped steel or steel bar,
The method for propelling a box structure according to any one of claims 2 to 4, wherein:

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