JP6296963B2 - Natural ground reinforcement method and structure - Google Patents

Description

  The present invention relates to a natural ground reinforcement method and structure applied when increasing slope stability and strength on sloped ground such as cut soil.

  On slopes exposed to natural slopes and cuts in mountainous areas, appropriate measures are taken according to the slope and soil properties to prevent weathering and erosion of slopes, as well as peeling, falling rocks, or collapse caused by them. Must.

  In order to prevent the collapse on the slope, as a measure appropriate for the case of a relatively large collapse, a tension is introduced into the tendon between the anchor body anchored in the ground and the pressure plate installed on the slope. A so-called ground anchor that stabilizes the natural ground by doing so is known.

  On the other hand, as a countermeasure suitable for the case where the scale of collapse is relatively small, a reinforcing material such as a lock bolt or deformed steel bar is inserted into the insertion hole formed in the natural ground, and between the hole wall of the insertion hole. There is known a so-called ground-reinforced earth method in which the stability of a natural ground is improved mainly by filling the grout material with the tensile resistance of the reinforcing material.

  Here, the earth-reinforced earth method is intended to resist mud slip due to the tensile force generated in the reinforcement due to deformation of the ground, and the tension is passive from the beginning in that it is passive. It is different from the ground anchor that suppresses the clot with the tensile force introduced as force, but like the ground anchor pressure plate, the load transmitting member is connected to the head of the reinforcing material and this is placed on the slope By doing so, if the load transmission member receives the force that the natural ground starts to move and supports it with the tensile force of the reinforcing material, the slope stability will be improved compared to when the load transmission member is not placed. For example, metal products are commercially available (Non-Patent Documents 1 and 2).

"Reaction body made of steel for rock bolt (cut reinforced earth method)" (NETIS new technology information system, May 4, 2014 search, URL: http://www.netis.mlit.go.jp/ NetisRev / Search / NtDetail1.asp? REG_NO = QS-020037 & TabType = 2 & nt = nt) “Green pressure type steel pressure plate for cut reinforced soil” (NETIS New Technology Information System, May 4, 2014 search, URL: http://www.netis.mlit.go.jp/NetisRev/Search /NtDetail1.asp?REG_NO=KT-070060&TabType=2&nt=nt)

  On the other hand, there is known a concrete spraying method that prevents the weathering and erosion of the slope by covering the slope with the shotcrete entirely. In many cases, it is used together with the earthwork method, and if the above-described load transmission member is employed, it is expected that the slope stability is further improved.

  However, since the commercially available load transmission members are designed on the assumption that they are placed directly on the slope, there is a contribution to the strength of the shotcrete when used in combination with a concrete sprayer. However, there was a problem that the design was over-designed, and as a result, the cost of ground reinforcement measures was high.

  The present invention has been made in consideration of the above-mentioned circumstances, and when using the natural ground reinforcement earth method and the concrete spraying method, the force to which the natural ground starts to move is applied to the reinforcing material in a more rational form. It is an object of the present invention to provide a method and structure for transmitting a natural ground.

In order to achieve the above object, the method for reinforcing natural ground according to the present invention is as described in claim 1, wherein the reinforcing material is inserted into the insertion hole formed in the natural ground extending behind the slope, and the head portion thereof extends from the slope. The reinforcing bar is inserted so as to protrude, and a grout material is filled between the reinforcing material and the hole wall of the insertion hole, and the reinforcing bar surrounds the head of the reinforcing material and along a plane parallel to the slope. And the concrete is sprayed onto the area where the reinforcing bars are arranged to construct a load transmission part joined to the head of the reinforcing material in the area, and in the form integrated with the load transmission part A ground reinforcement method for constructing shotcrete on a steel bar, wherein the reinforcing bar is pre-assembled as a reinforcing bar assembly in such a manner that the reinforcing bar is connected to a sleeve-like member and the sleeve-like member is positioned near the center. The solid is the inner peripheral surface of the sleeve-like member By screwing the male thread formed in the head of the reinforcing material formed female screw, it is intended to be attached to the head of the stiffener.

Moreover, the ground reinforcement structure according to the present invention is inserted into the insertion hole formed in the natural ground extending behind the slope and filled with a grout material between the hole wall of the insertion hole as described in claim 2. A reinforcing member formed on the sloped surface of the reinforcing member so as to be joined to a head portion protruding from the sloped surface, and to be integrated with the periphery of the load transmitting portion. by constituted by a shotcrete constructed on the slope face, the load transmitting portion, screwing the male thread formed in the female screw formed on the inner peripheral surface on the head of the reinforcing member that in A sleeve-like member attached to the head of the reinforcing member, and a shape connected to the sleeve-like member and arranged along a plane parallel to the slope so as to surround the head of the reinforcing member . Consists of rebar and concrete sprayed on the area where the rebar is placed A.

  In the natural ground reinforcement method and structure according to the present invention, the reinforcing material is inserted and installed in the natural ground spreading behind the slope like the conventional natural ground reinforcing earth method, but after the reinforcing material is installed, The reinforcing bars are arranged so as to surround the head of the reinforcing material and along a plane parallel to the above-mentioned slope, and then the concrete is sprayed on the area where the reinforcing bars are arranged to thereby apply the reinforcing material to the area. While constructing the load transmission part joined to the head, the shotcrete is constructed around the load transmission part so as to be integrated with the load transmission part.

  In this way, on the slope, the load transmitting part is constructed in a state where it is joined to the head of the reinforcing material, and the force that the natural ground is about to move is transmitted to the reinforcing material through the load transmitting part. Supported by the tensile resistance of the reinforcement.

  In addition, since the load transmission part is constructed by spraying concrete, it will have the same function as shotcrete, thus, together with the shotcrete built around it, weathering of the entire slope and Prevent erosion.

  Typically, spraying concrete to the area where the reinforcing bars are placed and concrete to the surrounding area are performed at the same time, but they can be integrated before the concrete of the load transmission part solidifies. As long as it is, simultaneous spraying is not always necessary.

What is per To place the rebar, on form a and the sleeve-like member for connecting the reinforcing bar in the sleeve-like member was preceded assembled as rebar assembly such that the vicinity of the center position, the iron muscle assembly, the sleeve The male screw formed on the head of the reinforcing member is screwed into the female screw formed on the inner peripheral surface of the member, thereby attaching to the head of the reinforcing member. If it does in this way, it will become possible to complete | finish a reinforcing bar arrangement | positioning process rapidly, and it will become possible to shorten the whole construction period.

Moreover, according to the above-mentioned structure, it becomes possible to join a load transmission part reliably and simply to the head of a reinforcing material.

It is a general view of the natural ground reinforcement structure 1 which concerns on this embodiment, (a) is a vertical sectional view, (b) is an arrow view seen from the AA line direction. The perspective view which showed the load transmission part 5 and the reinforcing bar assembly 23 which comprises it. The construction figure which showed the procedure which builds the natural ground reinforcement structure 1. Explanatory drawing which showed the effect | action of the natural ground reinforcement structure 1. FIG. The perspective view which showed the reinforcing bar assembly 53 which concerns on a modification.

  Embodiments of a natural ground reinforcement method and structure according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a natural ground reinforcing structure according to the present embodiment. As shown in the figure, the natural ground reinforcement structure 1 according to this embodiment includes a lock bolt 4 as a reinforcing material inserted and installed in a natural ground 3 extending behind a slope 2, and among the lock bolts, A load transmitting portion 5 constructed on the slope 2 so as to be joined to the head 7 protruding from the slope 2, and a blow constructed on the slope 2 so as to be integrated with the periphery of the load transmitting portion. It is made up of artificial concrete 6.

  As shown in FIG. 2, the load transmitting portion 5 includes a sleeve-like member 21 fitted into the head 7 of the lock bolt 4 and a reinforcing bar 22 connected to the sleeve-like member so that the sleeve-like member is positioned near the center. And a concrete 24 sprayed on a region where the reinforcing bars 22 are arranged.

  Here, a female screw 26 is formed on the inner peripheral surface of the sleeve-like member 21, and the female screw is screwed into a male screw 25 formed on the head 7 of the lock bolt 4, whereby a reinforcing bar assembly. 23 is attached to the head 7 of the lock bolt 4 so that the reinforcing bar 22 can be disposed so as to surround the head 7 of the lock bolt 4 and along a plane parallel to the slope 2.

  Although the load transmission part 5 is configured in a plate shape having a substantially square planar shape, the size and thickness of the load transmission part 5 are appropriately determined so as to have a strength sufficient to restrain the movement of the natural ground, and the load transmission part 5 may be commensurate with it. In addition, the specifications of the rebar assembly 23, that is, the number, shape, diameter, pitch, and the like of the rebars 22 are appropriately set.

  In order to construct the natural ground reinforcement structure 1 according to this embodiment, first, an insertion hole (not shown) into which the lock bolt 4 can be inserted is formed in the natural ground 3 to be reinforced.

  Next, the lock bolt 4 is inserted from the slope side opening of the insertion hole. The length of the lock bolt 4 is appropriately set such that the head 7 protrudes from the slope 2.

  Next, a grout material is filled between the lock bolt 4 and the hole wall of the insertion hole.

  After the grout material exhibits a predetermined strength, the female screw 26 of the sleeve-like member 21 is screwed into the male screw 25 formed on the head 7 of the lock bolt 4 as shown in FIG. The rebar assembly 23 is attached to the head 7 of the lock bolt 4.

  If it does in this way, the reinforcing bar 22 can be easily arrange | positioned along the surface parallel to the slope 2 so that the head 7 of the rock bolt 4 may be surrounded.

  The reinforcing bar assembly 23 may be assembled in advance at a factory or the like, and may be appropriately carried to the site.

  Next, as shown in FIG. 3 (b), the concrete is sprayed onto the region where the reinforcing bars 22 are arranged, that is, the reinforcing bar assembly 23, thereby constructing the load transmitting unit 5 in the region, The shotcrete 6 is constructed around it in an integrated manner.

  About the location which constructs shotcrete 6, what is necessary is just to lay a lath net etc. beforehand as needed like a conventional concrete shotcrete.

  In the natural ground reinforcement structure 1 according to the present embodiment, the load transmitting portion 5 is constructed on the slope 2 in a state of being joined to the head 7 of the lock bolt 4.

  Therefore, for example, as shown in FIG. 4, when the natural ground 3 starts to move along the sliding surface 41, the force acts on the back surface of the load transmitting portion 5 from the slope 2 and through the load transmitting portion. It is transmitted to the lock bolt 4 and supported by the tensile resistance of the lock bolt, and thus the movement of the natural ground 3 is suppressed.

  Moreover, since the load transmission part 5 is constructed | assembled by the spraying of concrete, it will have the same function as a shotcrete, and thus the whole slope 2 with the shotcrete 6 constructed around it. Prevents weathering and erosion.

  As described above, according to the natural ground reinforcement structure 1 and its construction method according to the present embodiment, the lock bolt 4 is inserted into the natural ground 3 spreading behind the slope 2 as in the conventional natural ground reinforcement earth method. After the lock bolt 4 is installed, the reinforcing bars 22 are arranged so as to surround the head 7 and along a plane parallel to the slope 2, and then the concrete is formed in the region where the reinforcing bars 22 are arranged. The load transmitting portion 5 joined to the head 7 of the lock bolt 4 is constructed on the slope 2 and the spray concrete 6 is constructed around the load transmitting portion so as to be integrated with the load transmitting portion. Therefore, the force that the natural ground 3 is about to move is transmitted to the lock bolt 4 through the load transmitting portion 5 and supported by the tensile resistance of the lock bolt.

  Therefore, in addition to the natural ground reinforcing action by the lock bolt 4, the natural earth pressing action by the load transmitting portion 5 is exhibited. Thus, even without using a commercially available load transmitting member, high slope stability and sufficient Reinforcement of natural ground at a reasonable cost while avoiding an increase in cost due to the use of a commercially available load transmission member that can be achieved with natural ground strength and assuming direct mounting on a slope. Countermeasures are possible.

  Moreover, according to the natural ground reinforcement structure 1 and its construction method according to the present embodiment, the reinforcing bar 22 is arranged on the slope 2 as the reinforcing bar assembly 23, so that the bar arrangement work can be completed in a short time. It becomes possible.

  In addition, since the sleeve-like member 21 of the reinforcing bar assembly 23 is configured to be able to be screwed onto the head 7 of the lock bolt 4, sufficient bonding strength between the head 7 of the lock bolt 4 and the load transmitting portion 5 is ensured. can do.

  In this embodiment, the sleeve-like member 21 and the reinforcing bar 22 connected to the sleeve-like member 21 constitute the reinforcing bar assembly 23. However, instead of this, the sleeve-like member 21 is omitted, and a grid-like welded wire mesh as shown in FIG. You may use the reinforcing bar assembly 53 which overlaps the reinforcing bar 51 assembled in the grid | lattice form on the (wire mesh) 52, and if it says further, in the form of the reinforcing bar assembly 23 or the reinforcing bar assembly 53, the reinforcing bar 22 and the reinforcing bar Instead of arranging 51 on the slope 2, after the installation of the lock bolt 4 is completed, the reinforcing bars may be arranged at the current position so as to surround the head 7 thereof.

  In these cases, as a method of joining the load transmitting portion to the head of the lock bolt 4, for example, a fixing member that can be fixed to the shotcrete 24 constituting the load transmitting portion, for example, a nut-like member is attached to the head of the lock bolt 4. It should just be attached to.

1 Natural ground reinforcement structure 2 Slope 3 Natural ground 4 Rock bolt (reinforcing material)
DESCRIPTION OF SYMBOLS 5 Load transmission part 6 Shotcrete 7 Head 21 Sleeve-like member 22,51 Reinforcement 23,53 Reinforcement assembly 24 Concrete 25 Male thread 26 Female thread

Claims (2)

A reinforcing material is inserted into an insertion hole formed in a natural mountain extending behind the slope so that the head protrudes from the slope, and a grout material is filled between the reinforcing material and the hole wall of the insertion hole. Then, a reinforcing bar is disposed so as to surround the head of the reinforcing member and along a plane parallel to the slope, and concrete is sprayed on the region where the reinforcing bar is disposed, whereby the head of the reinforcing member is applied to the region. A ground pile reinforcing method for constructing a shotcrete around a load transmitting portion joined to a portion and integrating the load transmitting portion with the load transmitting portion , wherein the reinforcing bar is connected to a sleeve-like member. In addition, the rebar assembly is pre-assembled so that the sleeve-like member is positioned near the center, and the rebar assembly is attached to the female screw formed on the inner peripheral surface of the sleeve-like member on the head of the reinforcing member. By screwing the formed male screw, Natural ground reinforcing method characterized by attaching to the head of the serial reinforcement. A reinforcing material that is inserted into an insertion hole formed in a natural mountain extending behind the slope and is filled with a grout material between the hole wall of the insertion hole, and a head of the reinforcing material that protrudes from the slope load transmission portion formed in the slope face so as to be joined and is constituted by a shotcrete constructed on the slope face so as to integrally therewith around the該荷heavy transmission unit, the load transmitting portion A sleeve-like member attached to the head of the reinforcing member by screwing a male screw formed on the head of the reinforcing member into a female screw formed on the inner peripheral surface; and It is composed of rebars that are connected and that are arranged along a plane parallel to the slope so as to surround the head of the reinforcing material, and concrete that is sprayed on the area where the rebars are placed. Natural ground reinforcement structure characterized by.

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