JP2013087591A - Checking method and improvement method for deformation characteristic of back-filling material, and segment assembly timbering body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for checking deformation characteristics of a back-filling material.SOLUTION: Crushed stones 6 are back-filled between an installed rock-utilization segment 4 and an inner surface of a drift while the rock-utilization segment 4 is annularly installed on the inner-space side of the excavated drift, and an annular segment assembly timbering body 5 capable of partially advancing to the side of natural ground is constructed. Subsequently, a predetermined load acting on the side of the natural ground from the inner-space side of the drift is placed on a part of the segment assembly timbering body 5. Since the amount of partial displacement of the assembly timbering body 5 is measured, deformation characteristics of the back-filled crushed stones 6 can be checked.

Description

  The present invention relates to a method for confirming the deformation characteristics of a backfill material, a method for improving the deformation characteristics of a backfill material, and a segment assembly support used in these methods.

  In geological disposal facilities for high-level radioactive waste, cement-based materials used for supporting works and grouts elute into groundwater, creating a highly alkaline environment. Such a highly alkaline environment causes alteration in bentonite-based soil materials and surrounding rocks used as cushioning materials and backfill materials, resulting in increased uncertainty in securing long-term performance.

  In order to solve such a problem, as shown in FIG. 1, a tunnel using a segment 104 using rock for supporting work has been proposed. As shown in FIG. 2, in the segment 104 using rock, a rock block 142 such as granite is arranged in a steel mold 141, and between the rock block 142 and the rock block 142 and between the rock block 142 and the mold. It is a composite segment in which a gap generated between the frame 141 is filled with mortar (not shown) (see, for example, Patent Document 1 and Non-Patent Document 1).

  By the way, even if a tunnel is constructed using a segment for the support work, when the inner surface of the tunnel (the excavation wall of the natural ground) protrudes as the excavation of the tunnel progresses, the deformation is not transmitted to the segment. The segment cannot resist the inland deformation of the natural ground. Thereby, when constructing a mine shaft using a segment for a support work, it is required to fill a gap formed between the segment and the inner surface of the mine shaft with a backfill material.

  For example, in the above-mentioned geological disposal facility for high-level radioactive waste, it is proposed to use crushed stone as a back-filling material because cement material is not used as much as possible (for example, Non-Patent Document 1 and Non-Patent Document 1). 2).

  However, even if the backfilling material is filled, if the filling is insufficient or the elastic modulus of the filled backfilling material is small, the segment cannot resist the deformation of the natural ground. Accordingly, in order for the supporting reaction force of the segment to exhibit a sufficient effect, the deformation characteristics of the backfilling material must be appropriate (the rigidity (Young's modulus) of the backfilling material must be large).

  In other words, the rigidity (Young's modulus) of the backfill material that fills between the segment and the inner surface of the tunnel (the excavated wall surface of the natural ground) is as large as possible, and the natural pressure is applied by deforming the natural ground to the inner side. It is desirable that the reaction force at the time of minute deformation of the backfill material is large.

  Recognizing these technical issues, research on the deformation characteristics of backfill materials is progressing. For example, as shown in FIG. 3, a cylindrical steel frame (inner diameter 300 mm, height 250 mm) 107 is filled with crushed stone (100 mm to 200 mm) 106 and a disk (outer diameter 300 mm) 108 is placed thereon. The test results obtained by determining the relationship between the displacement amount of the disc 108 and the loading stress are reported. In this test, when the expected support reaction force is 2 MPa, the displacement amount (initial displacement amount) until reaching the loading stress is 11 to 24 mm when only blow filling is performed as shown in FIG. It has been pointed out that the amount of displacement in the low-stress region during initial loading is a problem (see, for example, Non-Patent Document 2).

JP 2002-250795 A

Katsuhiko Hayashi, Satoshi Noguchi et al., "Research on reduction technology of cement materials used for tunnel support in high-level radioactive waste disposal facilities" Japan Atomic Energy Agency, Geological Disposal Research and Development Division, Geological Disposal Fundamental Research and Development Unit Hiroyuki Tada, Hiroo Kumasaka, et al., “Deformation characteristics test of backfilled crushed stone of rock use segment support construction and examination of tunnel stability”, Japan Society of Civil Engineers, 66th Annual Scientific Lecture (2011) p. 117-118

  However, in tunnels such as mountain tunnels, the deformation characteristics of the backfilling material do not become a problem, and the confirmation method for confirming the deformation characteristics of the backfilling material or the backfilling material when the deformation characteristics of the backfilling material are not sufficient. There is no established method for improving the deformation characteristics.

  The present invention has been made in view of the above, and a method for confirming the deformation characteristics of the backfill material for confirming the deformation characteristics of the backfill material and the deformation characteristics of the backfill material for improving the deformation characteristics of the backfill material. It is an object of the present invention to provide an improved method and a segment assembly support used in these methods.

  In order to solve the above-described problems and achieve the object, the present invention provides a backfill material between the installed segment and the inner surface of the mine shaft while the segment is annularly installed on the inner side of the excavated mine shaft. An annular segment assembly support body that can be filled and partly advanced to the natural ground side is constructed, and then a predetermined load acting on the natural ground side from the inner space side of the tunnel is loaded on the part, The amount of displacement is measured.

  In addition, the present invention fills a backfilling material between the installed segment and the inner surface of the mine shaft, while the segment is installed in an annular shape on the inner side of the excavated mine shaft, and a part can advance to the natural ground side An annular segment assembly supporting body is constructed, and thereafter, a vibration that acts from the inner space side of the tunnel to the natural ground side is applied to the part, and the backfill material is compacted.

  Further, the present invention is characterized in that, in the above-described invention, the backfilling material is further replenished in a gap generated by compacting the backfilling material.

  Further, the present invention is a segment assembly supporting body used in the above-described method, characterized in that a lid that closes an inspection window provided in a segment assembled in an annular shape can advance to the natural ground side.

  Further, the present invention is the above invention, wherein the inspection window has a window frame expanded from the inside to the outside of the segment, and the lid body is expanded from the inside to the outside of the segment. It has an outer shape that fits into the window frame.

  The method for confirming the deformation characteristics of the backfill material according to the present invention is to fill the backfill material between the installed segment and the inner surface of the tunnel, while installing the segment in an annular shape on the inner side of the excavated tunnel. Establish an annular segment assembly support body that can partially advance to the natural ground side, and then apply a predetermined load that acts on the natural ground side from the inside of the tunnel to a part that can advance to the natural ground side of the segment assembly support body Is measured, and the amount of displacement that can be advanced to the ground side of the segment assembly support is measured, so the deformation characteristics of the backfill material can be confirmed.

  The method for improving the deformation characteristics of the backfill material according to the present invention is to fill the backfill material between the installed segment and the inner surface of the tunnel, while installing the segment in an annular shape on the inner air side of the excavated tunnel. An annular segment assembly support body that can partially advance to the natural ground side is constructed, and then a vibration that acts from the inside of the tunnel to the natural ground side is added to a part of the segment assembly support body that can advance to the natural ground side. By compacting the backfill material, the deformation characteristics of the backfill material can be improved.

FIG. 1 is a half-sectional bird's-eye view showing a mine constructed using a rock utilization segment. FIG. 2 is a perspective view showing the rock utilization segment shown in FIG. FIG. 3 is a diagram showing a deformation test apparatus for obtaining the deformation characteristics of the backfill material, and is a diagram showing an example in which crushed stone is used for the backfill material. FIG. 4 is a diagram showing the deformation characteristics of the backfill material when crushed stone is used as the backfill material. FIG. 5 is a half-sectional bird's-eye view showing a mine constructed using a rock utilization segment. FIG. 6 is a perspective view showing the rock utilization segment shown in FIG. 5. FIG. 7 is a schematic cross-sectional view showing a rock utilization segment used in the method for confirming the deformation characteristics of backfilled crushed stone according to an embodiment of the present invention. 8-1 is a figure which shows the construction procedure of a segment assembly support body, Comprising: It is a figure which shows the state which installed the rock utilization segment and backfilled the crushed stone. FIG. 8-2 is a diagram illustrating a construction procedure of the segment assembly support body, and is a diagram illustrating a state in which the segment assembly support body is constructed. FIG. 8-3 is a diagram illustrating a state in which a support reaction force is applied to the segment assembly support body. FIG. 9 is a schematic cross-sectional view showing a state in which a predetermined load is loaded on the lid in the method for confirming the deformation characteristics of the backfill material according to the embodiment of the present invention. FIG. 10A is a schematic cross-sectional view showing a state when vibration is applied to the backfilled crushed stone in the method for improving the deformation characteristics of the backfilling material according to the embodiment of the present invention. FIG. 10-2 is a schematic cross-sectional view showing a state when vibration is applied to the backfilled crushed stone in the method for improving the deformation characteristics of the backfilling material according to the embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing a state in which crushed stone is replenished in the method for improving the deformation characteristics of the backfill material according to the embodiment of the present invention. FIG. 12 is a schematic cross-sectional view showing another example of a state in which crushed stone is replenished in the method for improving the deformation characteristics of the backfill material according to the embodiment of the present invention.

  Hereinafter, embodiments of a method for confirming deformation characteristics of a backfilling material, a method for improving the deformation characteristics of a backfilling material, and a segment assembly support used in these methods according to the present invention will be described in detail with reference to the drawings. To do. Here, as shown in FIG. 5, in the disposal facility 1 for burying and disposing of high-level radioactive waste, the segment assembly support body 5 is constructed with the segment 4 using rocks, and the crushed stone 6 is used as the backfill material. Although the example used is demonstrated, this invention is not limited by this.

  As shown in FIG. 5, the segment assembly support body 5 is for resisting the internal deformation of the natural ground 2 when the inner surface (the excavation wall surface of the natural ground) of the tunnel 3 protrudes. 3 is constructed in an annular shape on the inner space side. The segment assembly support body 5 is constructed by installing a plurality of segments 4 in an annular shape, and the segment assembly support body 5 constructed in the present embodiment is in a state that resists deformation of the inside of the natural ground 2. A part of segment 4 or a part of segment 4 is constructed so as to be able to advance to the natural ground side.

  As shown in FIG. 6, the segment 4 used in the present embodiment is a segment 4 using rocks (hereinafter referred to as “rock use segment 4”) as described above, and the steel mold 41 has granite. The rock block 42 is arranged evenly, and a mortar 44 is filled in a gap formed between the rock block 42 and the rock block 42 and between the rock block 42 and the mold 41. The rock utilization segment 4 is formed in a circular arc shape when viewed from the front, and the mold frame 41 is welded to the plate-shaped portion (steel plate) 411 and the plate-shaped portion 411 that are curved and formed into a circular arc shape when viewed from the front. A frame portion 412 formed in a box shape on 411 is provided. The formwork 41 used in the present embodiment has a plate-like portion 411 arranged on the inner side so that the plate-like portion 411 covers the inner side of the mine shaft 3 when it is installed on the inner air side of the mine shaft 3. The frame portion 412 is disposed outside. Thereby, although the rock utilization segment 4 of this Embodiment exposes the surface of the rock block 42 to an outer side surface, the outer side surface (surface facing a natural ground) is formed smoothly, and crushed stone Even when 6 (backfill material) is filled, the crushed stone 6 is not clogged.

  Moreover, as shown in FIG. 7, the rock utilization segment 4 used in the present embodiment is provided with an inspection window 43 at the center thereof. The inspection window 43 is configured such that a part of the rock utilization segment 4 (lid body 432) can be advanced to the natural mountain side, and a window frame 431 provided in the center of the rock utilization segment 4 and a lid for closing the window frame 431 A body 432 and a fixing jig 433 for fixing the lid 432 in a state where the lid 432 closes the window frame 431. The window frame 431 is formed so as to gradually expand from the inside to the outside of the rock utilization segment 4. The window frame 431 has a size that occupies 3% to 20% of the ground contact area of the rock utilization segment 4, for example, and is formed in a truncated pyramid shape or a truncated cone shape, for example. The lid 432 gradually expands from the inside to the outside of the rock utilization segment 4 and has an outer shape (a truncated pyramid shape or a truncated cone shape) that fits into the window frame 431. Thereby, the cover body 432 can advance from the inner space side of the tunnel 3 to the natural ground side, and does not retreat to the inner space side. In addition, the lid 432 closes the window frame 431, and the outer surface thereof is flush with the outer surface of the rock utilization segment 4, and the crushed stone 6 is also inspected when the crushed stone 6 (backing material) is filled. 43 will not clog. The window frame 431 and the lid body 432 are made of, for example, metal, and the lid body 432 can be fixed to the window frame 431 by welding the lid body 432 to the window frame 431.

  As shown in FIG. 11, among the rock utilization segments 4 used in the present embodiment, the inspection window 43A of the rock utilization segment 4A installed at the top end portion is provided with a replenishment port 432A1 in the lid 432A. The replenishment port 432A1 is for replenishing the crushed stone into the gap formed between the installed rock utilization segment 4 and the inner surface of the tunnel 3, and as shown in FIG. 11, penetrates the lid 432A in the vertical direction. Alternatively, as shown in FIG. 12, it may be one that penetrates the lid body 432A in an oblique direction.

  When constructing a mine shaft using the rock utilization segment 4 described above, as shown in FIG. 5, the mine shaft 3 is advanced while the segment assembly support body 5 is constructed on the inner space side of the excavated mine shaft 3. Specifically, the segment assembly support body 5 is sequentially constructed from the wellhead side to the face side, and the tunnel 3 is dug.

  When constructing the segment assembly support body 5, as shown in FIG. 8A, the rock utilization segment 4 and the tunnel are installed while the rock utilization segment 4 is installed in an annular shape inside the excavated tunnel 3. The crushed stone 6 is back-filled between the inner surface of 3. Specifically, every time several rock utilization segments 4 are installed, the crushed stone 6 is backfilled between the installed rock utilization segments 4 and the inner surface of the tunnel 3. In this way, when the rock utilization segment 4 is installed in an annular shape and the crushed stone 6 is backfilled between the installed rock utilization segment 4 and the inner surface of the tunnel 3, excavation is performed as shown in FIG. An annular segment assembly support body 5 is constructed on the inner space side of the mine shaft 3.

  Next, the deformation characteristics of the crushed stone 6 backfilled and filled using the inspection window 43 provided in the rock utilization segment 4 are confirmed. Specifically, as shown in FIG. 9, first, the fixing jig 433 (see FIG. 7) is removed, and the lid body 432 can be advanced from the inner space side of the mineway 3 to the natural ground side. Next, a loading device (for example, a hydraulic jack) P is applied to the lid body 432, a predetermined load is loaded on the lid body 432, and the amount of displacement of the lid body 432 at this time is measured. When the measured displacement amount is smaller than a predetermined value, the crushed stone 6 is filled evenly at a desired density, and a desired rigidity is exhibited. Thus, when the crushed stone 6 is filled evenly and the desired rigidity is exhibited, the annular segment assembly supporting body 5 resists the deformation of the natural ground 2 as shown in FIG. Become. In this case, a fixing jig 433 (see FIG. 7) is attached, and the lid 432 is fixed in a state where the lid 432 blocks the window frame 431. On the other hand, when the measured displacement amount is larger than a predetermined value, the crushed stone 6 is not filled with a desired density.

  When it is confirmed that the crushed stone 6 is not filled at a desired density, the deformation characteristics of the crushed stone 6 that is backfilled and filled are improved using the inspection window 43 provided in the rock utilization segment 4. Specifically, as shown in FIG. 10, a vibrating body (for example, a vibrator) B is applied to the lid body 432, and vibrations that act on the lid body 432 from the inner space side of the tunnel 3 to the natural ground side are applied. As a result, the crushed stone 6 is compacted, the packing density of the crushed stone 6 increases, and the volume occupied by the crushed stone 6 decreases. And the cover body 432 advances from the inner space side of the mine shaft 3 to the natural ground side. That is, since the cover 432 advances from the inner space side of the mine shaft 3 to the natural mountain side as the volume occupied by the crushed stone 6 decreases, if the cover 432 is fixed in this state, the rock utilization segment 4 and There is no gap between the natural ground 2. Note that there are several methods for fixing the lid body 432, for example, fixing by welding.

  In addition, when a gap is generated between the rock utilization segment 4A serving as the top end and the inner surface of the mine shaft 3 by applying a vibration that acts on the cover body 432 from the inner side of the mine shaft 3 to the natural ground side, As shown in FIG. 11 or FIG. 12, the deformation characteristics of the back-filled crushed stone 6 are improved by replenishing the crushed stone 6 from the replenishment port 432A1 provided in the lid 432A of the rock utilization segment 4A serving as the top end. .

  According to the method for checking the deformation characteristics of the backfill material according to the present embodiment described above, the backfilled crushed stones 6 are evenly filled at a desired density, or the backfilled crushed stones 6 are at a desired density. It can be confirmed whether it is not filled with.

  According to the method for improving the deformation characteristics of the backfill material according to the present embodiment described above, the deformation characteristics of the backfilled crushed stone 6 can be improved after the deformation characteristics of the backfilled crushed stone 6 are confirmed.

  Moreover, since the crushed stone 6 is replenished from the replenishment port 432A1 provided in the cover body 432A of the rock utilization segment 4A which becomes the top end portion, the gap formed between the rock utilization segment 4A which becomes the top end portion and the inner surface of the mine shaft 3 Can be filled.

DESCRIPTION OF SYMBOLS 1 Disposal facility 2 Ground mountain 3 Tunnel 4 Rock utilization segment 4A Rock utilization segment 41 Formwork 411 Plate-like part 412 Frame part 42 Rock block 43 Inspection window 43A Inspection window 431 Window frame 432 Lid body 432A Lid body 432A1 Replenishment port 433 Tool 44 Mortar 5 Segment assembly support 6 Crushed stone

Claims (5)

An annular segment assembly support that allows a backfill material to be filled between the installed segment and the inner surface of the tunnel, while a segment is installed in the inner ring side of the excavated tunnel, and a part can be advanced to the ground. Build the body,
Thereafter, a predetermined load acting on the part from the inner space side of the tunnel to the ground is loaded on the part, and the displacement amount of the part is measured. An annular segment assembly support that allows a backfill material to be filled between the installed segment and the inner surface of the tunnel, while a segment is installed in the inner ring side of the excavated tunnel, and a part can be advanced to the ground. Build the body,
Then, the vibration which acts from the inner space side of a tunnel to the natural ground side is added to the said part, and the said backfill material is compacted, The improvement method of the deformation | transformation characteristic of the backfill material characterized by the above-mentioned.   The method for improving deformation characteristics of a backfill material according to claim 2, further comprising replenishing the backfill material to a gap formed by compacting the backfill material.   A segment assembly support used in the method according to any one of claims 1 to 3, wherein a lid for closing an inspection window provided in a segment assembled in an annular shape can be advanced to a natural ground side. Support body.   The inspection window has a window frame that widens from the inside to the outside of the segment, and the lid has an outer shape that widens from the inside to the outside of the segment and fits into the window frame. The segment assembly support body of Claim 4 characterized by these.

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