JP2018145614A - Reinforcing structure for bedrock slope with long-term durability and construction method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing structure and a construction method thereof capable of not only ensuring a long-term durability by preventing toppling failures of a bedrock slope and landslides of a bedrock but reducing construction cost as using pressure plates is not needed.SOLUTION: A reinforcing structure is constructed by: arranging one or a plurality of reinforcing members 2 through one hole 1 or a plurality of holes 1 drilled across from a slope S to a moving bedrock region Gand immovable bedrock region G, each of which is longer than 5 m and equal to or less than 100 m; filling grout material 7 around the reinforcing member 2 in the drilled hole 1; and forming an anchoring zone for the reinforcing member 2 in both of the regions by curing the grout material 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reinforcing structure applied to a rock slope and a construction method thereof.

  The phenomenon that a rock slope that has creeped (a phenomenon in which the deformation of the rock increases with time) tilts and collapses is called a flexible top ring or top ring collapse. As a method of preventing this collapse, insert the tip 3m to 10m of the PC steel wire into the immobile rock, inject cement milk around it (fixing part), and fix the sheath around the PC steel wire in the moving ground. Is provided with a structure called a free length part (tensile part) in which the PC steel wire can expand and contract inside the sheath, and a concrete plate or steel plate structure called a pressure plate is provided on the ground surface. In response to this, a tensile force was introduced between the fixing portion and the pressure receiving plate, and the pressure receiving plate pressed down the surface portion of the moving soil block.

  However, steel products are often used at the joint between the PC steel wire and the pressure plate, and maintenance and repair costs are high when the durability of social capital over 100 years is desired. Furthermore, since the PC steel wire and the pressure receiving plate are heavy, there is a problem in workability on slopes with poor scaffolding. In response to such a problem, a method has been proposed in which the pressure receiving plate is configured in a lattice shape to reduce the weight as disclosed in, for example, JP-A-2006-79777.

Japanese Patent Laid-Open No. 2006-79777

  However, in the method of Patent Document 1, the manufacturing cost of the pressure plate occupies a large cost for anchor construction, and the durability of the joint between the PC steel wire head and the pressure plate exceeds 100 years. There is a problem that it is insufficient from the viewpoint of long-term reinforcement.

  Furthermore, for the top ring collapse described above, the rock mass that progresses inside the bedrock that occurs in the case of the top ring collapse, although the collapse of the moving mass can be secondarily suppressed by suppressing the surface layer of the slope by anchor work. There was a problem that the tilting itself could not be temporarily suppressed.

  Therefore, the present invention provides a reinforcing structure capable of preventing the top ring collapse on the rock slope and ensuring long-term durability and its construction method, and reduces the construction cost by eliminating the need for a pressure receiving plate. An object of the present invention is to provide a reinforced structure that can be used and a method for the construction thereof.

In order to solve the above problems, the rock slope reinforcement structure according to the present invention is:
A long reinforcing material with a length of more than 5m and less than 100m straddling both areas is placed in one or a plurality of holes drilled from the slope to the moving rock area and the immovable rock area, and grouted in the drilled hole around the reinforcing material The first feature is that the fixing portion of the reinforcing material is formed in both areas by filling the material and curing the grout material.

  Here, the moving bedrock area refers to the area where the top ring or rock landslide occurs, and the immovable rock area refers to the area where the top ring or rock landslide does not occur in the deep part. However, the boundary between the two areas is not strict, and there may be a partial area near the stationary rock area in the moving bed area where no top ring or landslide occurs, and near the moving bed area in the fixed bed area. There may be areas where top rings and rock landslides partially occur.

  According to the present invention, the top ring collapse on the rock slope occurs when many cracks distributed in parallel in the rock are opened and shifted, but the moving rock area where the top ring is generated and the top ring are generated. By placing reinforcing materials such as carbon fiber cables in the immovable bedrock area that is not deep, and grouting around each area to fix the bedrock and reinforcing body, the bedrock and reinforcing material can be integrated. The length of the reinforcing material is desirably 10 m or more.

  For this reason, the rock mass in which the reinforcing material is disposed across the two sections together with the fixing portion behaves as one lump like the reinforced concrete in which the reinforcing bars are disposed, and there is no occurrence of deviation in the cracks in the rock mass. For this reason, the top ring collapse on the rock slope and the landslide of the rock never progress.

The rock slope reinforcement structure according to the present invention is:
A second feature is that a free length section is formed by cutting the reinforcing material and the grout material between the fixing portions of the reinforcing material.

The rock slope reinforcement structure according to the present invention is:
A third feature is that a plurality of reinforcing materials are bundled and arranged in the perforated holes, and fixing portions formed in both areas are dispersed for each reinforcing material.

  Since the fixing portion of the reinforcing material is dispersed, the stress applied to the fixing portion is dispersed, and the local load applied to the rock is reduced (the ground is not easily broken). This contributes to the suppression of the progress of the top ring and the progress of the rock landslide.

The rock slope reinforcement structure according to the present invention is:
A bag body covering the perforated hole with a reinforcing material is disposed together with the reinforcing material, the grout material is filled into the bag body, and the grout material filled inside the bag body and the bag body from the inside of the bag body A fourth feature is that the reinforcing material and the rock in both areas are integrated through the both grout materials by hardening of the grout material leaked to the outside.

The construction method of the rock slope reinforcement structure according to the present invention,
A step of drilling one or a plurality of holes from the slope to the moving rock zone and the immovable bedrock zone, a step of arranging a long reinforcing material having a length of more than 5 m and not more than 100 m across the zone, and the reinforcing material It is a first feature that a step of filling a grout material around the perforated hole and a step of forming a fixing portion of the reinforcing material in both areas by curing the filled grout material.

The construction method of the rock slope reinforcement structure according to the present invention,
A step of drilling one or a plurality of holes from the slope to the moving rock area and the immovable rock area, and a plurality of long reinforcing materials having a length of more than 5 m and less than 100 m across the both holes are arranged in a bundle. A step of filling the pierced hole with a grout material, a step of forming a fixing portion of the reinforcing material in both areas by hardening of the filled grout material, and a reinforcing material between the fixing portion of the reinforcing material, A second feature is that it includes a step of cutting the grout material to form a free length section.

The construction method of the rock slope reinforcement structure according to the present invention,
A step of drilling one or a plurality of holes from the slope to the moving rock area and the immovable rock area, a long reinforcing material having a length of more than 5 m and not more than 100 m straddling both the holes, and a bag body covering the reinforcing material Both the grout material by filling the grout material inside the bag body, the grout material filled inside the bag body, and the grout material leaking from the inside of the bag body to the outside of the bag body. A third feature is that a step of integrating the reinforcing material and the rock in both sections through the material is provided.

  As described above, according to the present invention, the progress of the top ring collapse and the landslide of the rock mass can be suppressed, and the rock slope can be stabilized and the long-term durability can be ensured.

  In addition, since a pressure receiving plate installed on the rock slope is not necessary, the construction cost can be reduced.

  Furthermore, in the past, there was a concern that the anchor head and the pressure receiving plate mounting portion would not be durable in the long term due to metal rusting, but according to the present invention, the anchor head and pressure receiving plate mounting portion Since there is no such thing, this concern about durability has been eliminated.

  In addition, since there is no heavy pressure plate made of concrete or metal, the scenery is improved, and there is an effect that workability and workability of the construction are improved by using a lightweight material.

The whole sectional view showing the reinforcement structure of the rock slope which is the 1st embodiment of the present invention, Explanatory drawing which shows the middle of constructing the reinforcement structure of FIG. FIG. 1 is a partially enlarged view of FIG. FIG. 1 is a cross-sectional view taken along line AA in FIG. Explanatory drawing which forms a fixing part and a free length section by covering a reinforcing material with a sheath tube, Overall schematic sectional view showing a reinforcement structure of a rock slope according to a second embodiment of the present invention, It is principal part sectional drawing which shows the reinforcement structure of the rock slope which is the 3rd Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment of the present invention, and FIG. 1 is a sectional view in which a reinforcing structure according to the present invention is applied to a rock slope.

  The reinforcing material used in the present invention is preferably a light-weight material that does not easily deteriorate such as a carbon fiber cable, but is a cable such as a PC steel wire that is coated with a synthetic resin such as an epoxy resin or polyethylene, or a rod shape of an aramid resin. The body may be good. Although the present embodiment is an example using a plurality of cables (three in the illustrated example), the number of cables can be applied from 1 to about 10.

  Embodiment of this invention is described below according to a construction procedure.

Referring to FIG. 2, first, hole 1 having a length of more than 5 m to 50 m and a hole diameter of 65 to 200 mm is cut from the slope S to the creeped rock G using equipment such as a rotary passion (hole drilling machine). The cable (reinforcing material) 2 is inserted into the hole 1. Hole 1 is drilled toward immovable rock unit G ₂ deep from the mobile rock unit G ₁ top ring or the like is not generated top ring or the like occurs.

  In the cable 2, a spacer 3 for arranging the cable 2 at an appropriate position in the hole 1 and a grout injection pipe 4 for injecting cement milk (grouting material) into the hole 1 are fixed by a binding band 5. All of the accessories (spacer 3, grout injection tube 4, binding band 5) are accommodated in a cloth packer (bag body) 6 for avoiding leakage of the injected cement milk from the hole drilling portion. .

  After the cable 1 is inserted into the hole 1 together with the packer 6, cement milk 7 is injected from the grout injection tube 4. When the cement milk 7 is filled inside the packer 6, the packer 6 expands, and the cement milk 7 is made of the material of the packer 6 (if it is made of a cloth having a strong alkalinity such as aramid fiber or synthetic resin fiber, the mesh expands) As shown in FIG. 3 and FIG. 4, the gap between the surrounding rock mass and the packer 6 is filled, and hardening of the cement proceeds with time.

When the cement milk 7 is solidified, rock moving cable 2 rock zone G _1, rock cable 2 and immovable rock zone G ₂ are integrated, respectively. As shown in FIG. 1, the grout injection tube 4 is left in the hole 1 and only the exposed portion from the surface is removed.

According to the reinforcing structure of the present embodiment, since the cable 2 is firmly integrated with rock and immobile rock zone G ₂ rock moving rock zone G _1, the top ring decay is sufficiently suppressed mobile rock zone G ₁ . Rock movement rock zone G ₁ is unstable in the groundwater level rises due to heavy rain, even when attempting to landslide collapse to form a sliding surface, moving rock and rock immovable rock zone G ₂ deep slip surface since rock zone G ₁ is being connected by a cable 2, rock moving rock zone G ₁ does not cause a landslide (sliding).

  The use of the packer is also to avoid cracks developing in the bedrock that causes the top ring and the leakage of cement milk from the cracks. Use the packer for rocks with few cracks from which the cement milk leaks. The problem of leakage can be solved by using cement milk mixed with fibers.

  According to this embodiment, since the cable 2 has high durability and the fixing section extends over the entire surface, the slope can be kept stable for a very long time. In the case of the conventional method, the top ring phenomenon itself that occurs inside the bedrock could not be stopped, but in this method, the progress of the top ring itself can be stopped. The length of the cable 2 can be appropriately set in the range of more than 50 m to 100 m depending on the inside of the bedrock.

  In addition, since there is no heavy metallic pressure receiving plate, workability on the slope is improved and economic efficiency is improved.

The cable 2 shown in FIG. 1 forms a fixing section throughout, but as shown in FIG. 5, one or a plurality of sheath tubes 8 (the overall length is shorter than the overall length of the cable 2) are placed in the middle of the cable 2. Accordingly, the cable 2 and the cement may be separated from each other to form a free length section T2 between the fixing section T1. Forming a plurality of fixing portions by utilizing sheath tube 8 may be disposed respectively on the moving rock zone G ₁ and immovable rock zone G _2. Instead of the sheath tube, butyl rubber is wrapped in the middle of the cable 2, or in the case of PC steel wire, the sheath tube is filled with rust-preventive oil, and both ends of the sheath tube are sealed with butyl rubber and tape so that the rust-preventive oil does not leak It is possible to cut off the adhesion with cement by sealing with.

Figure 6 shows a second embodiment of the present invention, dispersion fixing portion formed in the moving rock zone G ₁ and immovable rock zone G ₂ for a plurality of cables 2A~2C the (fixing unit period) T1, respectively This is an example. In FIG. 5, accessories such as a hole and a packer are omitted for easy understanding.

  The sheath tube 8 shown in FIG. 5 is arranged with respect to a plurality of cables 2A to 2C (three cables 2 shown in FIG. 1) so that the front and rear positions are shifted from each other, and inserted into the hole together with other accessories, and the sheath Cement milk is filled in the hole around the tube, and by fixing the filled cement milk, a fixing portion (fixing portion section) T1 is formed in a section without the sheath pipe (the section covered with the sheath pipe is a free length section) Is formed).

  When there are a plurality of cables, the fixing unit can be increased according to the number of cables. For this reason, the fixing portion is limited to a part of the bedrock, not the entire length of the hole, and the stress acting on the fixing portion can be dispersed in several places. As shown in FIG. 6, by dispersing the fixing portions of the cable at different positions, even if ground breakdown is likely to occur when stress is concentrated, long-term durability can be ensured without causing ground breakdown. .

  FIG. 7 shows a third embodiment of the present invention. When the slope surface layer portion is made of soft collapsed soil, the mortar spraying surface 10 is formed to prevent the slope surface from collapsing. This is an example of reinforcement.

  As shown in the figure, in this embodiment, a wire mesh 11 is arranged on a slope, and a plate-like shape is formed on the top of the wire mesh 11 at the upper end of one cable 2 protruding from the slope among the plurality of cables 2 shown in FIG. A nut (high nut) 13 is fixed with an epoxy resin curing agent or the like through a washer (square washer) 12 and a mortar spraying surface 10 is formed thereon.

  According to this embodiment, even if the surface is soft collapse, it is possible to appropriately protect the surface and stop the progress of the top ring phenomenon occurring inside the rock.

  INDUSTRIAL APPLICABILITY The present invention can be widely used as a rock reinforcement structure and its construction method.

1 hole 2 cable (reinforcing material)
3 spacer 4 grout injection pipe 5 binding band 6 packer 7 cement milk 8 sheath pipe 10 mortar spraying surface 11 wire net 12 washer 13 nut G bedrock G ₁ moving bedrock area G ₂ fixed bedrock area S slope T1 fixing section (fixing section)
T2 Free length section (Free length section)

Claims (7)

  A long reinforcing material having a length of more than 5 m and not more than 100 m straddling both areas is arranged in one or a plurality of holes drilled from the slope to the moving rock area and the immovable rock area, and the holes drilled around the reinforcing material A rock slope reinforcement structure characterized in that a grout material is filled in and a fixing portion of the reinforcement material is formed in both areas by hardening of the grout material.   2. The rock slope reinforcing structure according to claim 1, wherein a free length section in which a reinforcing material and a grout material are cut off is formed between fixing section sections of the reinforcing material.   The plurality of reinforcing members are bundled and arranged in the perforated hole, and fixing portions formed in both areas for each reinforcing member are dispersed with each other. The reinforcement structure of the rock slope according to claim 2.   A bag body covering the perforated hole with a reinforcing material is disposed together with the reinforcing material, the grout material is filled inside the bag body, and the grout material filled inside the bag body and the bag from the inside of the bag body The reinforcing material and the rock mass in both areas are integrated through the both grout materials by hardening of the grout material leaked to the outside of the body. Reinforcement structure of rock slopes.   A step of drilling one or a plurality of holes from the slope to the moving rock zone and the immovable bedrock zone, a step of arranging a long reinforcing material having a length of more than 5 m and not more than 100 m across the zone, and the reinforcing material A rock slope reinforcing structure comprising: a step of filling a grout material around the perforated hole, and a step of forming a fixing portion of the reinforcing material in both areas by hardening of the filled grout material. Construction method.   A step of drilling one or a plurality of holes from the slope to the moving rock area and the immovable rock area, and a plurality of long reinforcing materials having a length of more than 5 m and less than 100 m across the both holes are arranged in a bundle. A step of filling the pierced hole with a grout material, a step of forming a fixing portion of the reinforcing material in both areas by hardening of the filled grout material, and a reinforcing material between the fixing portion of the reinforcing material, A method of constructing a rock slope reinforcement structure comprising a step of cutting a grout material to form a free length section.   A step of drilling one or a plurality of holes from the slope to the moving rock area and the immovable rock area, a long reinforcing material having a length of more than 5 m and not more than 100 m straddling both the holes, and a bag body covering the reinforcing material Both the grout material by filling the grout material inside the bag body, the grout material filled inside the bag body, and the grout material leaking from the inside of the bag body to the outside of the bag body. A method for constructing a reinforcement structure for a rock slope, comprising a step of integrating the reinforcing material and the rock in both sections through a material.

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