JPS6010100A - Self-drilling type lock bolt - Google Patents

Self-drilling type lock bolt

Info

Publication number
JPS6010100A
JPS6010100A JP11729883A JP11729883A JPS6010100A JP S6010100 A JPS6010100 A JP S6010100A JP 11729883 A JP11729883 A JP 11729883A JP 11729883 A JP11729883 A JP 11729883A JP S6010100 A JPS6010100 A JP S6010100A
Authority
JP
Japan
Prior art keywords
rock bolt
lock bolt
outer diameter
head
self
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP11729883A
Other languages
Japanese (ja)
Inventor
稔 山本
木川 冨男
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Priority to JP11729883A priority Critical patent/JPS6010100A/en
Publication of JPS6010100A publication Critical patent/JPS6010100A/en
Pending legal-status Critical Current

Links

Landscapes

  • Rock Bolts (AREA)

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。
(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 本発明は、ロックボルト自体によりその挿入孔を掘削す
るように、〃・つ、掘削用ヘッド全ロックボルト大仏の
抜は止め力を高めるためのアンカーとして使用するよう
に、ロックボルト本体の先端部に、前記ロックボルト本
体の外径より大なる外径を有した掘削用ヘッドを連結す
る七共に、no記掘削用ヘッドに、掘削土砂搬出用流体
の吐出ノズルを備えさせた自穿孔型ロックボルトに関す
る。
[Detailed Description of the Invention] The present invention is designed so that the insertion hole is excavated by the rock bolt itself, and the drilling head is used as an anchor to increase the force to prevent the entire lock bolt from being pulled out. , an excavation head having an outer diameter larger than the outer diameter of the rock bolt body is connected to the tip of the rock bolt body, and the excavation head described in no. This invention relates to a self-drilling lock bolt.

上記ロックボルトにあっては、ボルト押入時に、掘削土
#を水や空気等の土#搬出用流体により掘削孔内壁とロ
ックボルト本体のmlの環状通路?通して排出し、ロッ
クボルトが所定深さに入り込むと、掘削孔内壁とロック
ボルト本体の間の環状空間にセメントミルク等の固結材
を注入してロックボルトを地盤に固定するのであるが、
従来のロックボルトにあっては、前記環状通路をロック
ボルト本体によって形成するようになっていたために、
掘削土砂の排中性能が悪くなったり、ロックボルトの固
定強度が低くなる欠点があった。 すなわち、掘削用ヘ
ッドのロックボルト本体から横何方への突出量を大きく
シ、掘削用ヘッドの地盤に対する定着t−i実にするよ
うに形成すると、環状通路の横断面積が著るしく大にな
って土砂搬出用流体の搬送圧゛が低下し、土砂搬出速度
が遅くなるとか、土砂がロックボルト本体に付着した状
態で伐り、固結材に混入して固結材とロックボルト本体
の連結強度低下を招くのであり、逆に、環状通路の横断
面積を小さくシ、土砂搬出用流体の搬送圧が高くなるよ
うに、掘削用ヘッドのロックボルト本体からの突出ft
’r小さくすると、掘削用ヘッドの地盤への定着が悪く
々るのである。
In the case of the above rock bolt, when the bolt is pushed in, the excavated soil is transferred to an annular passage between the inner wall of the excavation hole and the rock bolt body using a soil transport fluid such as water or air. When the rock bolt enters the predetermined depth, cement milk or other solidifying material is injected into the annular space between the inner wall of the borehole and the rock bolt body to fix the rock bolt to the ground.
In conventional rock bolts, the annular passage was formed by the rock bolt body;
There were drawbacks such as poor excavation performance for excavated soil and low fixing strength of rock bolts. That is, if the amount of lateral protrusion of the excavation head from the rock bolt body is increased and the excavation head is formed to be more firmly fixed to the ground, the cross-sectional area of the annular passage becomes significantly large. The conveying pressure of the fluid for transporting earth and sand decreases, which slows down the earth and sand transport speed, or when earth and sand is cut while adhering to the rock bolt body, it mixes with the consolidation material, reducing the connection strength between the consolidation material and the rock bolt body. On the contrary, the cross-sectional area of the annular passage should be made small and the protrusion of the excavation head from the rock bolt body should be increased by ft to increase the conveying pressure of the fluid for transporting earth and sand.
If 'r is made smaller, the anchorage of the excavation head to the ground becomes worse.

本発明の目的は、掘削土砂の排出性能及び掘削用ヘッド
の地盤に対する定着のいずt′Lをも優nたロックボル
トを提供することにある。
An object of the present invention is to provide a rock bolt that is excellent in both discharge performance of excavated soil and fixation of the excavation head to the ground.

本発明の特徴構成は、冒記した自穿孔型ロックボルトに
おいて、前記掘削用ヘッドの外径より小なる外径の筒体
を、前記ロックボルト本体の埋設部をその全長にわたっ
て囲続する状態に、かつ、掘削孔に挿入された前記ロッ
クボルト本体に対してその基端側に抜き取り自在な状態
に備えさせt事にある。
A characteristic configuration of the present invention is that, in the above-mentioned self-drilling rock bolt, a cylindrical body having an outer diameter smaller than the outer diameter of the excavation head surrounds the buried portion of the rock bolt main body over its entire length. And, the lock bolt body inserted into the excavation hole is provided with a proximal end thereof in a removable state.

つまり、ボルト挿入時には、前記筒体を装着しておいて
、土砂搬出用通路を掘削孔内壁と筒体との間の環状通路
で形成し、固結材注入時にF11筒体を抜き取シ、固結
材注入用空間を掘削孔内壁とロックボルト本体で形■す
るものにしたから、土砂ぜ出用通路の横断面積を筒体に
よって小にでき、土砂搬出用通路の搬送圧が高くなるよ
うにできると共に、掘削用ヘッドの地盤への突入長さ?
大にでき、掘削用ヘッドの地盤に対する定着力が大にな
るようにできた。
In other words, when inserting the bolt, the cylindrical body is attached, and the earth and sand transport passage is formed by an annular passage between the inner wall of the excavation hole and the cylindrical body, and when the consolidating material is injected, the F11 cylindrical body is removed. Since the space for injecting the consolidating material is formed by the inner wall of the excavation hole and the rock bolt body, the cross-sectional area of the passage for earth and sand can be reduced by the cylindrical body, and the conveying pressure of the passage for earth and sand can be increased. How long can the drilling head plunge into the ground?
It was possible to increase the anchoring force of the excavation head to the ground.

もって、打設が土砂排出の面から能率よくできると共に
ボルト固定が強固にできるようになった。
As a result, pouring can be done more efficiently in terms of earth and sand removal, and the bolts can be securely fixed.

以下に、本発明の実施例を図面に基いて説明する。Embodiments of the present invention will be described below based on the drawings.

m1図に示すように、中実棒製ロックボルト本体(11
の外径(住)より大なる外径CDI) Th備えさせた
掘削用ヘッド(2)を、ロックボルト本体(1)の補強
と固結材に対する連結強度の向上?図る几めの螺旋条(
la)t″利用ての螺着によりロックボルト本体(1)
の先端部に一体回動可能に連結し、掘削用ヘッド(2)
の外径CD、)より小なる外径CD、)を有すると共に
ロックボルト本体(1)の地盤への埋設部をその全長に
わたって囲続する筒体(al t−sロックボルト本体
+1)の基端側への抜き取シ操作のみによって恥外せる
ように、かつ、掘削用ヘッド(2)と一体面′動するよ
うに掘削用ヘッド(2)の後部の小径部に外嵌させると
共に掘削用ヘラF(2)の突部(ga)K係止させ、そ
して、掘削用ヘラF +21 K 吐出ノズル【4)t
−備えさせると共に、前記筒体(11とロックボルト本
体(1)の間に備えさせた環状空間(5)と、第2図示
すように前記螺旋条(la)に形成された切欠きにより
ロックボルト本体(1)と掘削用ヘッド(2)の同に形
■される間隙(6)とによって、掘削用ヘッド(2)を
冷却させると共に掘削土砂を掘削孔外に搬出させる水又
は空気等の流体(al ’r吐出ノズル14Hc供給す
る流路を形成し、さらに、掘削孔にセメントミルク等の
固結材(1)1を注入−1″るパイプ17) t 、″
前記筒体(3)内に配置すると共にロックボルト本体(
1)fcD、付臭(81Kより固定し、もって、次に詳
述する如くして打設する自穿孔型ロックボルト?構成し
である。
As shown in figure m1, the solid rod rock bolt body (11
Excavation head (2) with an outer diameter (CDI) that is larger than the outer diameter of The elaborate spiral striations (
The lock bolt body (1) is screwed using la)t''.
The excavation head (2) is connected to the tip of the
The base of a cylindrical body (al t-s rock bolt body + 1) which has an outer diameter CD, ) smaller than that of The excavating spatula is fitted onto the small diameter portion at the rear of the excavating head (2) so that it can be removed only by pulling it out toward the end, and so that it moves integrally with the excavating head (2). Lock the protrusion (ga) K of F (2), and then insert the excavating spatula F +21 K discharge nozzle [4) t
- An annular space (5) provided between the cylindrical body (11) and the lock bolt body (1), and a notch formed in the spiral thread (la) as shown in Figure 2 to lock the lock. The gap (6) formed in the same shape between the bolt body (1) and the drilling head (2) allows water or air to cool the drilling head (2) and transport the excavated earth and sand out of the drilling hole. A pipe 17) that forms a flow path for supplying fluid (al'r discharge nozzle 14Hc) and further injects a solidifying material (1) 1 such as cement milk into the excavation hole.
The lock bolt body (
1) It is composed of a self-drilling lock bolt that is fixed from fcD and odorized (81K) and is driven as detailed below.

すなわち、第1図に示すように、ロックボルト本体+1
1の基端側に備えである対打設機着脱部(lb)l螺着
するように、かつ、前記筒体(3)の基端部を抜き取シ
自在に内嵌させてロックボルト本体(11に固定するよ
うに構成したナツト部(9a)を備えさせた取付治具(
9)t″介して、ロックボルトな前記筒体(3)の装着
しである状態で削岩機等の打設機(101K取付けると
共に、前記取付治具(91に備えである流路1111と
、第8図に示すように前記螺旋条(1m)の切欠きとの
協働によってIiI記流路11+1 ’に筒体(3)の
内部に連通させるように前記ナツト部(9m)K形成し
である切欠き121とによシ、前記環状空間(5)t−
打設機(IO)の流体供給部に連通させておき、第4図
に示すように、打設機QOI Kより掘削用ヘッド+2
1 K回動力と打撃を付与してボルト挿入孔を掘削しな
がら、かつ、掘削用ヘッド(2)から土砂搬出用流体1
al t−吐出させ、この流体(岨の圧送作用によシ、
掘削土砂を掘削孔内壁と筒体(3)の間の環状通路Ql
全通して孔外に排出しながらボルト挿入2行う。
That is, as shown in Fig. 1, the lock bolt body +1
1, and the lock bolt body (lb) is screwed onto the base end of the cylindrical body (3), and the base end of the cylindrical body (3) is inserted into the lock bolt body so as to be removable. (A mounting jig equipped with a nut part (9a) configured to be fixed to 11 (
9) Attach the cylindrical body (3), which is a rock bolt, through the mounting tool (101K) such as a rock drill, and connect the flow path 1111 provided in the mounting jig (91). , as shown in FIG. 8, the nut portion (9m) K is formed so as to communicate with the inside of the cylinder body (3) through the flow passage 11+1' marked IiI by cooperating with the notch of the spiral strip (1m). With the notch 121, the annular space (5) t-
It is connected to the fluid supply part of the pouring machine (IO), and as shown in Fig. 4, the drilling head +2 is connected to the pouring machine QOI K.
While drilling the bolt insertion hole by applying 1K rotational force and impact, the earth and sand transporting fluid 1 is applied from the excavation head (2).
al t-discharge, this fluid (due to the pumping action of the
The excavated soil is passed through the annular passage Ql between the inner wall of the excavation hole and the cylinder (3).
Insert the bolt 2 while passing it all the way through and draining it out of the hole.

そして、ロックボルトが所定深さに入り込むと、第5図
に示すように、ロックボルト本体11)を掘削孔に押入
したままで、取付治具(9)を取外して筒体(3)ヲ抜
き収る。 そして、前記ノ(イブ(7)に固結材注入袋
@(図外)を接続し、固結材(b)?パイプ(7)の先
端開口から掘削孔内壁とロックボルト本体filの間の
環状空間に注入すると共に固化させ、固結材(blの連
結作用と掘削用ヘッド(2)のアンカー作用とにより、
ロックボルト本体tt+ V地盤に定着するのである。
When the lock bolt has entered the predetermined depth, the mounting jig (9) is removed and the cylindrical body (3) is removed while the lock bolt body 11) remains pushed into the excavated hole, as shown in Fig. 5. It fits. Then, connect a consolidating material injection bag @ (not shown) to the pipe (7), and connect the consolidating material (b) through the tip opening of the pipe (7) between the inner wall of the excavation hole and the rock bolt body fil. It is injected into the annular space and solidified, and by the connecting action of the solidifying material (BL) and the anchoring action of the excavation head (2),
The rock bolt body tt+V is fixed to the ground.

第2図に示す(2b)は掘削用ヘッド(2)の掘削刃で
ある。
(2b) shown in FIG. 2 is the excavating blade of the excavating head (2).

尚、本発明は、ロックボルト本体を中空欅製とし、その
内部を通して土砂搬送用流体及び固結材を供給するよう
に構成するロックボルトにも適用できる−0 又、その
場合には、筒体として、そnとロックボルト本体の間に
環状空間が形成されない厚肉なものを採用してもよいの
である。
The present invention can also be applied to a rock bolt whose main body is made of hollow zelkova and is configured to supply earth and sand conveying fluid and consolidation material through the inside. As such, a thick one that does not form an annular space between the bolt and the lock bolt body may be used.

【図面の簡単な説明】[Brief explanation of the drawing]

図面は本発明に係る自穿孔型ロックボルトの実施例?示
し、第1図はロックボルトの一部切欠き一側面図、第2
図は@1図の■−■断面矢視図、第8図は第1図の■−
■断面矢視図、第4図はロックボルトの挿入状態を示す
脱1刀図、第5図は固結材の注入状懲ヲ示す説明図であ
る。 (1)・・・・・・ロックボルト本体、(21・・・・
・・掘削用ヘッド、(3)・・・・・・筒体、(4)・
・・・・・吐出ノズル、CD□)・・・・・・掘削用ヘ
ッド外径、CDり・・・・・・筒体外径、(d)・・・
・・・ロックボルト本体外径、惧)・・・・・・土砂搬
出用流体。 ■−糸売 袖 HX が、: 昭 4++ 6 7 ++ j 月 /111゛11イ
゛1のノ;小 昭和5811− % 願 第117298j;2 発明
の渭h、 自穿孔型ロックボルト 3 補正をする者 弔(’Iとの関イに4寺 許 出駈1人住所 東京都町
田市玉川学IE/−/J−,2(ほか7名) 4代Ig!人 昭和 イ1 月 11(発送11) 7、 補正の内容 +1+ 明細書中、7頁/3行目と/l/行目どの間に
次文を挿入する。 「又、前記土砂搬送用流体(a)の供給流R; 1.’
r成に対する変形例として、第6図ないし第8図に示す
ように、前記取付治具(9)のうちロックボルト本体(
1)の対打設+Q a説の外周との間に環状流路θ3)
を形成するリング04)を、連結部分(9a)の中心軸
芯(P)周りで相対回転自在に、かつ、連結部分 (9a)との間に環状流路u菊に対するシールリング(
16)を介装した状態で外嵌状にJrz付けると共に、
連結部分(9a)の内部螺合孔と環状流路O萄とを連通
ずる連通孔(1(9の枚数を連結部分(9a)に、その
周方向に等間隔配置して穿設し、かつ、リングθ4)に
3Ep。 伏流路(l騰への流体供給用流路(+7)を形成し、も
って、取付治具(9)に備えである流路(11)から空
気(al)を、かつ、リングθ4)の流体供給用流路α
乃から水(a2)を供給して、それら空気(a、)と水
(叫)とを連結部分(9a)の内部都合孔内で混合させ
、土砂搬送用流体(a)として空気(al)と水(a2
)との混合流体をヘッド(2)の吐出ノズル(4)から
吐出させるように構成しても良い。」 (2) 同、F頁2行目から2行目の「図面は・・・説
明図である。」を次文に訂正する。 r第1図ないし第5図は本発明の実施例を示し、第1図
は一部省略縦断面図、第2図は第1図のm−mg断面矢
視図、第8図は第1図の■−■縮断面矢視図、第4図は
ロックボルトの挿入状態を示す説明図、第5図は固結材
の注入状態を示す説明図である。 第6図ないし第8図は本発明の別実施 例を示し、第6図は一部省略縦断面図、第7図は第6図
の■−■綴矢視図、第8図は第6図の■−■線断面矢視
図である。」(3)図面中、「第6図」、「第7図」、
及び、「第8図」を追加する。 8、 添付書類目録 追加図面 1通
Is the drawing an example of the self-drilling lock bolt according to the present invention? Figure 1 is a partially cutaway side view of the lock bolt, Figure 2 is a partially cutaway side view of the lock bolt.
The figure is the ■-■ cross-sectional view of Figure 1, and Figure 8 is the ■-■ cross-sectional view of Figure 1.
(2) A sectional view in the direction of the arrows, FIG. 4 is a removed view showing the state of insertion of the lock bolt, and FIG. 5 is an explanatory view showing the injection state of the solidifying material. (1)...Rock bolt body, (21...
・・Drilling head, (3)・・Cylinder body, (4)・
...Discharge nozzle, CD□) ...Excavation head outer diameter, CDri ...Cylinder outer diameter, (d)...
...Other diameter of rock bolt body, 3) ...Fluid for transporting earth and sand. - Thread sales sleeve HX is: Showa 4++ 6 7 ++ j month /111゛11i゛1 no; Showa 5811- % Application No. 117298j; 2 Invention of Weih, Self-drilling type lock bolt 3 Make correction Condolences (4 temples in connection with 'I) 1 person Address: Manabu Tamagawa, Machida City, Tokyo IE/-/J-, 2 (and 7 others) 4th generation Ig! Showa I January 11 (shipped 11) ) 7. Contents of the amendment +1+ Insert the following sentence between page 7/line 3 and /l/ line in the specification. '
As a modification to the R configuration, as shown in FIGS. 6 to 8, the lock bolt body (
An annular channel θ3) between the paired pouring of 1) and the outer periphery of theory a
The ring 04) forming the connecting part (9a) is relatively rotatable around the central axis (P) of the connecting part (9a), and a sealing ring (
16) while attaching Jrz to the outside in a state where it is interposed,
Communication holes (1 (9) are drilled in the connecting part (9a) at equal intervals in the circumferential direction thereof, and , 3Ep in the ring θ4). A flow path (+7) for supplying fluid to the underground flow path (l rise) is formed, and air (al) is supplied from the flow path (11) provided in the mounting jig (9). And the fluid supply channel α of the ring θ4)
Water (a2) is supplied from the tank, and the air (a,) and water are mixed in the internal hole of the connecting part (9a), and the air (al) is used as the sediment transport fluid (a). and water (a2
) may be configured to be discharged from the discharge nozzle (4) of the head (2). ” (2) Same, on page F, lines 2 to 2, “The drawing is an explanatory drawing.” is corrected to the following sentence. r Figures 1 to 5 show embodiments of the present invention, in which Figure 1 is a partially omitted vertical cross-sectional view, Figure 2 is a cross-sectional view taken along the line m-mg in Figure 1, and Figure 8 is a cross-sectional view of Figure 1. FIG. 4 is an explanatory diagram showing a state in which a lock bolt is inserted, and FIG. 5 is an explanatory diagram showing a state in which a consolidation material is injected. 6 to 8 show other embodiments of the present invention, FIG. 6 is a partially omitted vertical sectional view, FIG. It is a sectional view taken along the line ■-■ in the figure. (3) In the drawings, "Figure 6", "Figure 7",
And, "Figure 8" is added. 8. 1 copy of additional drawings for attached document list

Claims (1)

【特許請求の範囲】[Claims] ロックボルト本体filの先端部に、lロ記ロックボル
ト本体111の外径(41ニジ大なる外径(Dl)?有
した掘削用ヘッド(21ヲ連結すると共に、前記掘削用
ヘッド(2)に、掘削土砂搬出用流体tjLlの吐出ノ
ズルn+v備えさせた自穿孔型ロックボルトであって、
前記掘削用ヘッド(21の外径(Dl)より小なる外径
(D、)の筒体(3)を、前記ロックボルト本体fil
の埋設部をその全長にわたって囲続する状態に、かつ、
掘削孔に挿入された前記ロックボルト本体+1) VC
対してその基端側に抜き取り自在な状態に備えさせであ
る自穿孔型ロックボルト。
An excavating head (21) having an outer diameter (Dl) larger than the outer diameter (Dl) of the lock bolt main body 111 is connected to the tip of the rock bolt main body fil, and the excavating head (21) is connected to the distal end of the rock bolt main body fil. , a self-drilling rock bolt equipped with a discharge nozzle n+v of a fluid tjLl for carrying out excavated earth and sand,
A cylindrical body (3) having an outer diameter (D,) smaller than the outer diameter (Dl) of the excavation head (21) is attached to the rock bolt body fil.
surrounding the buried part over its entire length, and
The rock bolt body inserted into the excavation hole +1) VC
On the other hand, there is a self-drilling lock bolt that is provided at its base end so that it can be freely extracted.
JP11729883A 1983-06-29 1983-06-29 Self-drilling type lock bolt Pending JPS6010100A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11729883A JPS6010100A (en) 1983-06-29 1983-06-29 Self-drilling type lock bolt

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11729883A JPS6010100A (en) 1983-06-29 1983-06-29 Self-drilling type lock bolt

Publications (1)

Publication Number Publication Date
JPS6010100A true JPS6010100A (en) 1985-01-19

Family

ID=14708286

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11729883A Pending JPS6010100A (en) 1983-06-29 1983-06-29 Self-drilling type lock bolt

Country Status (1)

Country Link
JP (1) JPS6010100A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006526718A (en) * 2003-06-03 2006-11-24 デューンファィアー プロプライアタリー リミティド Rock bolt

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006526718A (en) * 2003-06-03 2006-11-24 デューンファィアー プロプライアタリー リミティド Rock bolt

Similar Documents

Publication Publication Date Title
JP4288331B2 (en) Rock bolt and supporting method using the same
JPS6010100A (en) Self-drilling type lock bolt
JP2019112786A (en) Self-drilling rock bolt and natural ground reinforcement method using the same
JPH11200750A (en) Excavation bit for winding hole and execution method using it
JPS622120B2 (en)
JP7169214B2 (en) Mouth pipe and construction method using it
JP3851590B2 (en) Preceding ground mountain consolidation method using self-drilling bolt and FRP bolt
JPS6215359Y2 (en)
JP3113635B2 (en) Composite injection non-widened steel pipe tip receiving method
JP2553336Y2 (en) Injection fixing type support member
JP3868176B2 (en) Soil-stabilized steel pipe for ground stabilization and ground stabilization method using this steel pipe
JP2000204899A (en) Self-drilling anchor
JP7436983B2 (en) drilling bit
JP2527213Y2 (en) Lock bolt device
JPH0560040B2 (en)
JP2544702B2 (en) Pipe rod construction method
JP3100347B2 (en) Construction method of ground reinforcement bolt
JP3515046B2 (en) Ground reinforcement method
JP3125053B2 (en) Crack injection equipment
JPH06200524A (en) Lock anchor
JP2559019Y2 (en) Lock bolt device
JP3328817B2 (en) Ground reinforcement method
JP2022164110A (en) Rock bolt structure and rock mass reinforcement structure
JP3249952B2 (en) Multi-stage steel pipe injection system
JP2004360393A (en) Injection device for grout and grouting method