JP4074514B2

JP4074514B2 - Pressure-receiving structure and formwork used during construction

Info

Publication number: JP4074514B2
Application number: JP2002377654A
Authority: JP
Inventors: 卓嗣濱田; 久嗣立花; 豊繁谷川
Original assignee: 株式会社ダイクレ
Priority date: 2002-12-26
Filing date: 2002-12-26
Publication date: 2008-04-09
Anticipated expiration: 2022-12-26
Also published as: JP2004204638A

Description

【０００１】
【発明が属する技術分野】
本発明は、自然地山や切土などの斜面に埋設した鉄筋やアンカーボルト等（以下、単に「鉄筋等」という）により斜面の土圧を支持する斜面補強工法において使用する受圧構造物と、その施工時において、斜面より突出する鉄筋の周りにグラウトを注入する際に用いる型枠に関する。
【０００２】
【従来技術】
【特許文献１】
特開平６−８８３４１号
【特許文献２】
特開２０００−３３６６５６号
【０００３】
斜面補強工法の一つに、斜面を削孔して鉄筋を挿入し、その周りにグラウトを注入して鉄筋を固め、斜面にラス鋼を定着したのち、斜面から突出する鉄筋に法面プレートを通し、ついで鉄筋突出端部にナットを捩込んで締着固定したのちコンクリートを吹き付ける工法が知られ、特許文献１には、該工法において、鉄筋による補強効果を高めるため法面プレートの定着面積を大きくした場合において生ずる重量増大の問題に対処するため、法面プレートを格子状にしたものが提案されている。
【０００４】
また特許文献２には、斜面に掘削した孔にアンカーボルト（ねじ節鉄筋）を挿入して、
その周りにグラウトを注入して固定し、斜面からの突出部分に格子状の受圧構造物を１ないし複数重ねて差し込んだのち、その上に更に押え板を差し込んで重ね、ついで押え板より突出するアンカーボルトの突出端にナットを捩込んで締着固定する工法が開示されている。
【０００５】
【発明が解決しようとする課題】
特許文献１に開示される法面プレートは、ナットで押えて固定されるが、鉄筋に作用する引張力や剪断力をナットで受けているため、ナットに集中荷重が加わって法面プレートが撓み、周縁が斜面より浮いたり、斜面への加圧力が低下し、鉄筋による補強効果が小さくなる。また、その表面にはコンクリートが吹き付けられるため植生ができない。
【０００６】
この点、特許文献２に開示される受圧構造物は、押え板により比較的広い範囲で押えられ、応力分散が行われて押え板全体で受圧構造物を押えることができるため強固に固定することができる利点があり、植生も可能である。
本発明の第１の目的は、こうした受圧構造物について更に改良を加え、軽量化するものである。
【０００７】
【課題の解決手段】
請求項１に係わる発明は、第１の目的を達成する受圧構造物に関するもので、自然地山や切土などの斜面に埋設した鉄筋等の斜面から突出する突出部分に無数の開口を形成し、厚みが全体で均一である受圧構造物を１ないし複数差込み、更にその上に押え板を差し込んで重ね、ついで鉄筋等の突出端にナットを捩込んで、締着固定し、押え板により受圧構造物に作用する応力を周辺に分散させて受圧構造物を構成する枠全てで斜面を押える斜面補強工法において使用する上記受圧構造物であって、環状の枠を同心円状に配すると共に、桟を放射状に配して一体化したものである。
【０００８】
本発明によると、同心円状に配した環状の枠と、放射状の桟とで弧状の開口が無数に形成されるが、この開口は、鉄筋等が差し込まれる中心部の差込孔から周辺に向かってサイズが次第に大きくなる。ナットの捩込みにより受圧構造物を締着し固定したとき、押え板によって受圧構造物に作用する応力は周辺に分散され、受圧構造物周縁での応力は小さなものとなるため、受圧構造物を構成する素材が周縁に向かうにつれ疎となり、剛性が小さくなっても何等支障がない。すなわち周縁では、中心部ほど密にして剛性を高める必要がないから、受圧構造物全体が軽量化される。
【０００９】
受圧構造物の材質としては、鋼製であってもよいが、軽量で、かなりな剛性を有するＦＲＰや硬質樹脂製のものが望ましい。
請求項２に係わる発明は、請求項１に係わる発明の受圧構造物において、同心円状に配した環状の枠を用いる代わりに渦巻状の枠を用いてなるものである。
本発明においても、請求項１に係わる発明と同様の作用効果を生ずる。
【００１０】
請求項３に係わる発明は、請求項１又は２に係わる発明において、押え板には、受圧構造物に形成される開口に差し込まれる突起を突設してなるものである。本発明によると、
ナットを捩込むとき、押え板が廻り止めされるため、締着作業が容易となり、また押え板が回動することにより受圧構造物と摺接して受圧構造物を傷めることがない。
【００１１】
請求項４に係わる発明は、請求項３に係わる発明において、金属板をプレスで打ち抜き折曲加工して突起付きの押え板を形成してなるものである。
本発明によると、押え板をプレス加工により一工程で安価に製作することができる。
【００１２】
【発明の実施の形態】
図１に示す受圧構造物１は、同心円状に定間隔で配した環状の枠２と、放射状に配した桟３を組合せて、蜘蛛の巣状に一体成形してなるもので、ＦＲＰ製よりなっている。
【００１３】
図２は、斜面５に埋設したねじ節鉄筋６に図１に示す受圧構造物１を固定した例を示すもので、その施工は従前のように、斜面５に削孔した孔７に鉄筋等としてのねじ節鉄筋６を挿入したのち、受圧構造物１を斜面上に鉄筋６に通して装着し、ついで下側部を蛇腹状にした円筒状の硬質樹脂ないし金属製の型枠８を鉄筋６の突出端部に嵌まるようにして挿入し、上端のフランジ８ａが受圧構造物１に当たるまで強く押し込む。これにより蛇腹が縮まり、型枠下端が斜面５に強く押し付けられる。
【００１４】
次に型枠８内にグラウト９を注入し、鉄筋６の周りの削孔した孔７や型枠８内の空洞部に充填する。グラウト９の注入は、図２の丸で囲まれるように、型枠上端に達するまで行われ、注入後、押え板１１を鉄筋６の突出端部に差込み、ついでピン状の突起１２を最も内側の枠２とその外側の枠２の間の桟３間の開口に差し込んで、押え板１１を受圧構造物１上に重ね、鉄筋突出端部よりナット１３を捩込んで締着し固定する。図中、１４は鉄筋６の突出端部に被せられ、ナット１３を被覆するキャップである。
【００１５】
本実施形態の受圧構造物によると、押え板により受圧構造物を押えるため、応力集中を防ぐことができ、開口４を通して植生ができること、内外の環状枠２と両側の桟３とで形成される円弧状の開口４が周縁に向かうにつれサイズが次第に大きくなり、剛性も低下するが、中心部から周縁に向かうにつれ斜面５を押え付けたときの斜面から受ける力も小さくなり、何等支障がない。そのため格子状の受圧構造物より重量が軽減されること、開口４のサイズが大きくなることにより比較的サイズの大きな植物の植生が可能となること、
押え板１１は、突起１２を開口４に差し込むことにより廻り止めされるため、ナット１３を捩込むときに連れ廻りすることがなく、押え板１１が受圧構造物１を摺接してＦＲＰ製の受圧構造物１を傷めることがないこと、斜面５より突出する鉄筋６の周りに型枠８を設けることにより、受圧構造物１と斜面５との間の隙間にグラウトを流出させることなく、
また型枠８を強く押し込むことにより蛇腹部分が収縮して斜面５に強く押し付けられるようになるため、グラウト注入時に型枠８と斜面５との間より洩出することがなく、したがって少量のグラウト９で斜面５より突出して露出する部分を確実に被覆し、防錆処理することができること等の効果を奏する。
【００１６】
図３は、押え板１６の別の例を示すもので、金属板をプレスで打ち抜いて突起６ａを折曲加工してなるものである。
図４は、別の例の受圧構造物１９を示すもので、図１に示す受圧構造物１において、桟３を僅かな間隙を存して平行に二条ずつ形成してなるものである。
【００１７】
本実施形態の受圧構造物１９によると、桟３を二条に形成することにより強度及び剛性が増して、内外の枠２と二条の桟間との間の開口のサイズを大きくし、よりサイズの大きな植物の植生が可能となる。
図５は、更に別の例の受圧構造物２１を示すもので、図１に示す受圧構造物１において、枠２を渦巻条をなす枠２２とし、最外側の環状の枠２に連結した構成をなすものである。
【００１８】
図６は、更に別の例の受圧構造物２４を示すもので、図１に示す受圧構造物１において、最外側の枠２を正方形の枠２５としたものである。
【００１９】
【発明の効果】
請求項１及び２に係わる発明によると、押え板により受圧構造物を押えるため、応力集中を防ぐことができ、開口を通して植生ができること、受圧構造物としては開口のサイズを周縁に向かうにつれ大きくでき、それにより何の支障も生じないため、受圧構造物の重量を軽減することができ、植生される植物のサイズも大きくできること等の効果を奏する。
【００２０】
請求項３に係わる発明によると、ナットを捩込むとき、押え板が連れ周りすることがないため、締着作業が容易となり、受圧構造物を摺接して受圧構造物を傷めることがない。
請求項４に係わる発明によると、突起付きの押え板をプレス加工により一工程で安価に
製作することができる。
【００２１】
【図面の簡単な説明】
【図１】本発明に係わる受圧構造物の平面図。
【図２】図１に示す受圧構造物の施工例を示す断面図。
【図３】押え板の変形態様を示す断面図。
【図４】本発明に係わる受圧構造物の別の例を示す平面図。
【図５】本発明に係わる受圧構造物の更に別の例を示す平面図。
【図６】本発明に係わる受圧構造物の更に別の例を示す平面図。
【符号の説明】
１、１９、２１、２４・・受圧構造物
２、２２、２５・・枠
３・・桟
４・・開口
５・・斜面
６・・ねじ節鉄筋
７・・削孔した孔
８・・型枠
９・・グラウト
１１、１６・・押え板
１２、１６ａ・・突起
１３・・ナット
１４・・キャップ[0001]
[Technical field to which the invention belongs]
The present invention is a pressure receiving structure used in a slope reinforcement method for supporting earth pressure on a slope by reinforcing bars or anchor bolts (hereinafter simply referred to as “rebar etc.”) embedded in slopes such as natural ground mountains and cuts, The present invention relates to a mold used for injecting grout around a reinforcing bar protruding from a slope during construction.
[0002]
[Prior art]
[Patent Document 1]
JP-A-6-88341 [Patent Document 2]
JP 2000-336656 A
One of the slope reinforcement methods is drilling a slope, inserting a reinforcing bar, injecting grout around it, hardening the reinforcing bar, fixing lath steel on the slope, and then attaching a slope plate to the reinforcing bar protruding from the slope. Next, a method is known in which a nut is screwed and fixed to a protruding end of a reinforcing bar, and then concrete is sprayed. Patent Document 1 discloses a fixing method for a slope plate in order to enhance the reinforcing effect of the reinforcing bar. In order to cope with the problem of weight increase that occurs when the size is increased, a slope plate having a grid shape has been proposed.
[0004]
In Patent Document 2, an anchor bolt (screw joint) is inserted into a hole excavated on a slope,
A grout is injected and fixed around it, and one or more grid-type pressure-receiving structures are inserted into the protruding portion from the slope, and then a presser plate is further inserted on top of it, and then protrudes from the presser plate. A method of tightening and fixing a nut to a protruding end of an anchor bolt is disclosed.
[0005]
[Problems to be solved by the invention]
The slope plate disclosed in Patent Document 1 is fixed by being pressed with a nut. However, since the nut receives a tensile force and a shearing force acting on the reinforcing bar, the concentrated plate is subjected to a concentrated load and the slope plate is bent. The peripheral edge is lifted from the slope, the pressure applied to the slope is lowered, and the reinforcing effect by the reinforcing bars is reduced. In addition, vegetation is impossible because concrete is sprayed on the surface.
[0006]
In this regard, the pressure receiving structure disclosed in Patent Document 2 is held in a relatively wide range by the holding plate, and the pressure distribution structure can be pressed by the entire holding plate because the stress is distributed, so that the pressure receiving structure is firmly fixed. There is an advantage that can be done, and vegetation is also possible.
The first object of the present invention is to further improve and reduce the weight of such a pressure receiving structure.
[000 7 ]
[Means for solving problems]
The invention according to claim 1 relates to a pressure-receiving structure that achieves the first object, wherein innumerable openings are formed in protruding portions that protrude from slopes such as reinforcing bars embedded in slopes such as natural ground and cut soil. , a thickness of the whole uniform pressure structure of one or plural plug further superimposed on the insert the presser plate thereof, then nuts Nde Sujikomi the projecting end of such reinforcing steel, and fastening fixing, pressure by the pressing plate The pressure receiving structure used in the slope reinforcement method in which the stress acting on the structure is distributed to the periphery to hold the slope with all the frames constituting the pressure receiving structure, and the annular frame is arranged concentrically, and Are integrated in a radial pattern.
[000 8 ]
According to the present invention, an infinite number of arc-shaped openings are formed by concentric annular frames and radial bars, and these openings are directed from the central insertion hole into which the rebar is inserted toward the periphery. The size gradually increases. When the pressure receiving structure is fastened and fixed by screwing in the nut, the stress acting on the pressure receiving structure by the holding plate is dispersed to the periphery, and the stress at the periphery of the pressure receiving structure becomes small. The material to be constructed becomes sparse as it goes to the periphery, and there is no problem even if the rigidity is reduced. That is, at the periphery, it is not necessary to increase the rigidity by making it denser as the center portion, so that the entire pressure receiving structure is reduced in weight.
[00 09 ]
The material of the pressure receiving structure may be made of steel, but is preferably light weight and made of FRP or hard resin having considerable rigidity.
The invention according to claim 2 is the pressure receiving structure of the invention according to claim 1, wherein a spiral frame is used instead of a concentric annular frame.
In the present invention, the same effect as that of the invention according to claim 1 is produced.
[00 10 ]
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the presser plate is provided with a protrusion to be inserted into an opening formed in the pressure receiving structure. According to the present invention,
When the nut is screwed in, the presser plate is prevented from rotating, so that the tightening work is facilitated, and the presser plate is not rotated and slidably contacted with the pressure receiving structure so that the pressure receiving structure is not damaged.
[00 11 ]
The invention according to claim 4 is the invention according to claim 3, wherein a press plate with protrusions is formed by punching and bending a metal plate with a press.
According to the present invention, the presser plate can be manufactured at a low cost in one step by press working.
[00 12 ]
DETAILED DESCRIPTION OF THE INVENTION
The pressure receiving structure 1 shown in FIG. 1 is formed by combining annular frames 2 concentrically arranged at regular intervals and bars 3 arranged radially, and integrally formed in a spider web shape. It has become.
[00 13 ]
FIG. 2 shows an example in which the pressure receiving structure 1 shown in FIG. 1 is fixed to a screw joint reinforcing bar 6 embedded in the slope 5, and the construction is performed in the hole 7 drilled in the slope 5 in the conventional manner. Then, the pressure-receiving structure 1 is mounted on the slope through the reinforcing bar 6 and then the cylindrical hard resin or metal mold 8 having a bellows on the lower side is attached to the reinforcing bar. 6 is inserted so as to fit into the protruding end portion 6, and the upper end flange 8 a is pushed in firmly until it hits the pressure receiving structure 1. As a result, the bellows is contracted, and the lower end of the mold is strongly pressed against the inclined surface 5.
[00 14 ]
Next, the grout 9 is injected into the mold 8 to fill the hole 7 drilled around the reinforcing bar 6 and the hollow portion in the mold 8. The injection of the grout 9 is carried out until reaching the upper end of the mold so as to be surrounded by a circle in FIG. 2. After the injection, the presser plate 11 is inserted into the protruding end of the reinforcing bar 6, and then the pin-like protrusion 12 is placed on the innermost side. Is inserted into the opening between the frame 2 between the frame 2 and the outer frame 2, the presser plate 11 is overlaid on the pressure receiving structure 1, and a nut 13 is screwed in from the protruding end of the reinforcing bar to be fastened and fixed. In the figure, reference numeral 14 denotes a cap that covers the protruding end portion of the reinforcing bar 6 and covers the nut 13.
[00 15 ]
According to the pressure receiving structure of this embodiment, since the pressure receiving structure is pressed by the presser plate, stress concentration can be prevented, vegetation can be made through the opening 4, and the inner and outer annular frames 2 and the crosspieces 3 on both sides are formed. As the arcuate opening 4 moves toward the periphery, the size gradually increases and the rigidity also decreases. However, as it moves from the center toward the periphery, the force received from the inclined surface when the inclined surface 5 is pressed decreases, and there is no problem. Therefore, the weight is reduced from the lattice-shaped pressure receiving structure, and the size of the opening 4 is increased, so that a relatively large plant can be vegetated.
Since the presser plate 11 is stopped by inserting the protrusion 12 into the opening 4, the presser plate 11 does not rotate when the nut 13 is screwed in, and the presser plate 11 slidably contacts the pressure receiving structure 1 to receive the pressure received from FRP. Without damaging the structure 1, by providing the mold 8 around the reinforcing bar 6 protruding from the slope 5, without letting the grout flow into the gap between the pressure receiving structure 1 and the slope 5,
Further, when the mold 8 is strongly pressed, the bellows portion contracts and is strongly pressed against the inclined surface 5, so that no leakage occurs between the mold 8 and the inclined surface 5 when the grout is injected. 9 shows an effect that the portion protruding from the slope 5 to be exposed can be reliably covered and rust-proofed.
[00 16 ]
FIG. 3 shows another example of the presser plate 16, which is formed by punching a metal plate with a press and bending the protrusion 6a.
FIG. 4 shows another example of the pressure receiving structure 19, in which the crosspieces 3 are formed in parallel in two lines with a slight gap in the pressure receiving structure 1 shown in FIG. 1.
[00 17 ]
According to the pressure receiving structure 19 of the present embodiment, the strength and rigidity are increased by forming the crosspieces 3 in two lines, and the size of the opening between the inner and outer frames 2 and the two bars is increased. Large plant vegetation is possible.
FIG. 5 shows still another example of the pressure receiving structure 21. In the pressure receiving structure 1 shown in FIG. 1, the frame 2 is a spiral frame 22 and is connected to the outermost annular frame 2. It is what makes.
[00 18 ]
FIG. 6 shows another example of the pressure receiving structure 24, and in the pressure receiving structure 1 shown in FIG. 1, the outermost frame 2 is a square frame 25.
[00 19 ]
【The invention's effect】
According to the inventions related to claims 1 and 2, since the pressure receiving structure is pressed by the presser plate, stress concentration can be prevented, vegetation can be made through the opening, and as the pressure receiving structure, the size of the opening can be increased toward the periphery. Since this does not cause any trouble, the weight of the pressure receiving structure can be reduced, and the size of the plant to be vegetated can be increased.
[00 20 ]
According to the third aspect of the present invention, when the nut is screwed in, the presser plate is not rotated around, so that the fastening operation is facilitated, and the pressure receiving structure is not slid and damaged.
According to the fourth aspect of the present invention, the presser plate with the projection can be manufactured at a low cost in one step by pressing.
[00 21 ]
[Brief description of the drawings]
FIG. 1 is a plan view of a pressure receiving structure according to the present invention.
2 is a cross-sectional view showing a construction example of the pressure receiving structure shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing a deformation mode of a presser plate.
FIG. 4 is a plan view showing another example of a pressure receiving structure according to the present invention.
FIG. 5 is a plan view showing still another example of a pressure receiving structure according to the present invention.
FIG. 6 is a plan view showing still another example of a pressure receiving structure according to the present invention.
[Explanation of symbols]
1, 19, 21, 24 ··· Pressure receiving structures 2, 22, 25 · · Frame 3 · · Cross 4 · · Opening 5 · · Slope 6 · · Screw rebar 7 · · Drilled hole 8 · · Formwork 9. · Grout 11, 16 · · Presser plate 12, 16a · · Protrusion 13 · · Nut 14 · · Cap

Claims

An infinite number of openings are formed in the protruding part that protrudes from the slopes of rebars embedded in slopes such as natural ground and cuts , and a pressure receiving structure with a uniform thickness is inserted, and a presser plate is inserted on top of it. in superposed, then Sujikomi Nde nuts protruding end of such reinforcing steel, fastening and fixing, the stress acting on the pressure receiving structure is dispersed around the presser plate pressing a slope on all frames constituting the pressure-receiving structure slopes In the pressure receiving structure used in the reinforcement method, the annular frame is arranged concentrically,
A pressure-receiving structure characterized by integrating crosses in a radial pattern.

2. The pressure receiving structure according to claim 1, wherein a spiral frame is used instead of the concentric circular frame.

The pressure receiving structure according to claim 1 or 2, wherein a protrusion inserted into an opening formed in the pressure receiving structure is provided on the presser plate.

4. The pressure receiving structure according to claim 3, wherein the presser plate with protrusions is formed by punching and bending a metal plate with a press.