JP2004076371A

JP2004076371A - Disruption preventing method for mt. fuji

Info

Publication number: JP2004076371A
Application number: JP2002237273A
Authority: JP
Inventors: Seiichi Ozawa; 小沢　清一
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-08-16
Filing date: 2002-08-16
Publication date: 2004-03-11
Anticipated expiration: 2022-08-16
Also published as: JP3704110B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disruption prevention method for Mt. Fuji capable of shortening a construction period and reducing construction cost. <P>SOLUTION: In this disruption preventing method for Mt. Fuji, a large number of support piles 1 formed by fixing steel bases 11 to lower ends of a reinforced concrete column bodies (3) are manufactured beforehand, and a large number of protective plates 21 formed by providing lock parts 25 to upper edges 23a of reinforced concrete plate-like bodies 23 are manufactured beforehand. The large number of the support piles are dropped in the air from a helicopter to a slope 35, placed at specified intervals, and installed vertically, and the protective plates are suspended from the helicopter by the lock parts, and vertically installed in a state of hanging on the support piles. Then, a large number of the protective plates are continuously disposed on the slope to form a continuous protective plate 38, and multiple stages of the continuous protective plates are formed on the slope. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、富士山の崩壊予防方法に関するものであり、更に詳しくは富士山大沢崩れに絶え間なく続いている土砂の崩落を防止することにより富士山の崩壊を予防する方法に係るものである。
【０００２】
【従来の技術】
富士山大沢崩れにおいては、山頂から標高約２，０００メートルの高さまで、長さ約２，０００メートル、幅約５００メートル、深さ約１５０メートルにわたって土砂の崩落が長年続いている。このような土砂の崩落を放置すれば、わが国の国宝ともいうべき美しい富士山は、やがては崩壊、変形するおそれがある。
【０００３】
そこで、富士山大沢崩れにおける崩壊を防止するために、床固式低ダム工、渓岸保護工、斜面基礎工、覆式落石防護網工等の試験施工が行われている。
【０００４】
【発明が解決しようとする課題】
上記各工法は、いずれも工事に長い期間と膨大な費用を要すると共に、土砂の崩落による作業員の危険を伴うものである。
【０００５】
本発明は、上記従来の工法における上述の如き問題を解決し、短期間で安全に且つ少ない費用で施工することができる富士山の崩壊予防方法を提供するものである。
【０００６】
【課題を解決するための手段】
上記課題を解決するために、本発明は下記の富士山の崩壊予防方法を提供する。
【０００７】
鉄筋コンクリート製の柱体における鉄筋の下部を該柱体の下端より露出させ、該鉄筋の下部におねじを備えさせ、鉄製の基部には該鉄筋下部のおねじに対応するめねじを備えさせ、該基部には下部に尖端を備えさせ、該鉄筋下部のおねじを該基部のめねじに螺合させることにより該柱体の下端に該基部を固定してなる支持杭を予め多数本製造し、
鉄筋コンクリート製の板状体の上縁に係止部を備えさせてなる防護板を予め多数枚製造し、
ヘリコプターにより空中から前記支持杭を傾斜地に投下して該支持杭の基部を地中に埋入することにより、多数本の支持杭を柱体が地上に突出した状態で該傾斜地に所定の間隔を置いて立設し、
続いて、前記防護板を前記係止部を介してヘリコプターにより吊り下げて該防護板を該傾斜地における前記支持杭の上側にて該支持杭に立て掛けた状態で立設することにより、該傾斜地に多数枚の防護板を連続させた状態で配設して連続防護板を形成し、
該連続防護板を該傾斜地に多数段設けることを特徴とする富士山の崩壊予防方法。
【０００８】
【作用】
各支持杭は鉄筋コンクリート製の柱体の下端には下部に尖端を備えた鉄製の基部を固定してなるものであり、柱体に比べて基部の重量が大きい。従って、支持杭をヘリコプターにより空中から傾斜地に投下して該支持杭の基部を地中に埋入させ、柱体を地上に突出させた状態で該支持杭を該傾斜地に立設することができる。ヘリコプターは、支持杭の鉄製基部が傾斜地に埋入するに足る高度から傾斜地に支持杭を勢いよく投下し、打ち込む。
【０００９】
防護板もヘリコプターにより吊り下げて該防護板を傾斜地における支持杭の上側に該支持杭に立て掛けた状態で立設する。防護板は空中から傾斜地に勢いよく投下するのではなく、傾斜地に静かに降ろし、支持杭に立て掛けるのである。
【００１０】
即ち、支持杭を傾斜地に立設する作業も、防護板を該傾斜地に立設する作業も、ヘリコプターにより空中から行うことができる。
【００１１】
傾斜地に多数枚の防護板を連続させた状態で配設してなる連続防護板は土砂の崩落を防止する。この連続防護板を該傾斜地に多数段設けることにより、土砂の崩落は確実に防止される。
【００１２】
【発明の実施の形態】
次に、本発明の実施の形態を添付図面に従って説明する。
【００１３】
本発明による富士山の崩壊予防方法は下記の通りである。
【００１４】
（１）支持杭の製造（図４、図５参照）
多数本の支持杭１を予め製造する。各支持杭１は、鉄筋コンクリート製の柱体３における鉄筋５の下部７を該柱体３の下端３ａより露出させ、該鉄筋５の下部７におねじ９を備えさせ、鉄製の基部１１には該鉄筋下部７のおねじ９に対応するめねじ１３を備えさせ、該基部１１には下部に尖端１５を備えさせ、該鉄筋下部７のおねじ９を該基部１１のめねじ１３に螺合させることにより該柱体３の下端３ａに該基部１１を固定してなるものである。
【００１５】
鉄製の基部１１の重量は、一例として、支持杭１全体の重量の約２／３とする。また、基部１１における尖端１５の角度１７（図５参照）は一例として約３０度とする。
【００１６】
なお、支持杭１における柱体３は基部１１よりも若干小径に形成することにより、支持杭１の打ち込み時における該柱体３と土砂との摩擦を小さくすることが望ましい。
【００１７】
（２）防護板の製造（図６、図７参照）
防護板２１を予め多数枚製造する。各防護板２１は、鉄筋コンクリート製の板状体２３の上縁２３ａに係止部２５を備えさせてなるものである。係止部２５は板状体２３内の鉄筋２７を板状体２３の上縁２３ａより上方に突出させると共に該鉄筋２７の上端を例えば環状に形成してなるものとする。この場合、上端に係止部２５を備えている鉄筋２７は板状体２３内において下端を屈曲させて屈曲部２９を形成することにより、該防護板２１を該係止部２５を介してヘリコプターにより吊り下げたときに該鉄筋２７が抜け出すことを防止することが望ましい。符号３１に示すものは、上端に係止部２５を備えた鉄筋２７以外の鉄筋である。
【００１８】
図７においては、縦方向の鉄筋３１と横方向の鉄筋３１との交差部３３を鉄線３４により結束している。
【００１９】
（３）支持杭の立設
ヘリコプターにより空中から支持杭１を傾斜地３５に投下して該支持杭１の基部１１を地中に埋入することにより、多数本の支持杭１を柱体３が地上に突出した状態で該傾斜地３５に所定の間隔を置いて立設する。
【００２０】
（４）連続防護板の形成
防護板２１を係止部２５を介してヘリコプターにより吊り下げて該防護板２１を傾斜地３５における支持杭１の上側（図２における左側）にて該支持杭１に立て掛けた状態で立設することにより、該傾斜地３５に多数枚の防護板２１を連続させた状態で配設して連続防護板３８を形成する。
【００２１】
防護板２１を係止部２５を介してヘリコプターにより吊り下げる際には、一例として、下端にフック部３７を有するワイヤ等の吊り下げ紐３９をヘリコプターに備えさせ、該吊り下げ紐３９のフック部３７に防護板２１の係止部２５を係止する。防護板２１を傾斜地３５における支持杭１の上側にて支持杭１に立て掛けた後、吊り下げ紐３９のフック部３７を防護板２１の係止部２５から引き抜く。
【００２２】
防護板２１と隣接する防護板２１との合わせ目４１は、図１に示すように、支持杭１により支持させることが望ましい。
【００２３】
（５）連続防護板の多段配設
上記連続防護板３８を傾斜地３に上下方向に多数段設ける。
【００２４】
【発明の効果】
以上説明したように、本発明によれば、支持杭と防護板とを予め製造しておき、現場では支持杭をヘリコプターにより空中から傾斜地に投下立設すると共に防護板をヘリコプターにより吊り下げて支持杭に立て掛けることにより傾斜地に連続防護板を多数段設けるようにしたため、工事に要する期間は短縮され、工事に要する費用も軽減される。更に、現場での工事をヘリコプターにより行うようにしたため、土砂の崩落による作業員の危険は排除される。
【図面の簡単な説明】
【図１】連続防護板を示す正面図である。
【図２】連続防護板を複数段設けた状態を示す側面図である。
【図３】同上の平面図である。
【図４】傾斜地に投下される支持杭の断面図である。
【図５】支持杭の一部を示す断面図である。
【図６】吊り下げられた防護板の断面図である。
【図７】防護板における鉄筋を鉄線により結束した状態を示す正面図である。
【図８】防護板の平面断面図である。
【符号の説明】
１　支持杭
３　柱体
３ａ　下端
５　鉄筋
７　下部
９　おねじ
１１　基部
１３　めねじ
１５　尖端
２１　防護板
２３　板状体
２３ａ　上縁
２５　係止部
２７　鉄筋
２９　屈曲部
３１　鉄筋
３３　交差部
３４　鉄線
３５　傾斜地
３７　フック部
３８　連続防護板
３９　吊り下げ紐
４１　合わせ目[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for preventing the collapse of Mt. Fuji, and more particularly to a method for preventing the collapse of Mt. Fuji by preventing the collapse of earth and sand continuously following the Mt.
[0002]
[Prior art]
At Mt. Fuji Osawa Collapse, the collapse of earth and sand has continued for about 2,000 meters in length, about 500 meters in width, and about 150 meters in depth from the summit to a height of about 2,000 meters above sea level for many years. If such landslides are left untouched, the beautiful Mount Fuji, which can be called Japan's national treasure, may eventually collapse or deform.
[0003]
In order to prevent the collapse of Mt. Fuji Osawa collapsing, test construction of floor-fixed low dam works, shore protection works, slope foundation works, overturned rock fall protection net works, etc. is being carried out.
[0004]
[Problems to be solved by the invention]
Each of the above construction methods requires a long period of time and enormous cost for the construction, and involves a danger for workers due to the collapse of the earth and sand.
[0005]
The present invention solves the above-mentioned problems in the conventional method, and provides a method for preventing collapse of Mt. Fuji that can be performed safely and at low cost in a short period of time.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides the following method for preventing collapse of Mt. Fuji.
[0007]
A lower part of the reinforcing bar in the reinforced concrete column is exposed from a lower end of the column, a screw is provided at a lower portion of the reinforcing bar, and a steel base is provided with a female screw corresponding to an external thread of the lower portion of the reinforcing bar. The base is provided with a pointed tip at the bottom, and a number of support piles are manufactured in advance by fixing the base to the lower end of the column by screwing an external thread of the rebar into an internal thread of the base,
A large number of protective plates, which are provided with locking portions on the upper edge of a reinforced concrete plate, are manufactured in advance,
By dropping the support pile onto the slope from the air with a helicopter and burying the base of the support pile in the ground, a large number of support piles are spaced from the slope at a predetermined interval in a state where the pillars protrude above the ground. Put it up,
Subsequently, the protection plate is suspended by a helicopter via the locking portion, and the protection plate is erected on the support pile on the inclined land on the upper side of the support pile, thereby standing on the inclined land. A large number of protective plates are arranged in a continuous state to form a continuous protective plate,
A method for preventing collapse of Mt. Fuji, comprising providing a plurality of the continuous protective plates on the slope.
[0008]
[Action]
Each support pile is formed by fixing an iron base provided with a pointed tip at the lower end of a reinforced concrete pillar, and the weight of the base is larger than that of the pillar. Therefore, the support pile can be dropped from the air onto the slope by a helicopter, the base of the support pile can be buried in the ground, and the support pile can be erected on the slope with the pillar protruding above the ground. . The helicopter will drop and hammer the support stake into the sloping ground from an altitude sufficient for the steel base of the supporting stake to be embedded in the sloping ground.
[0009]
The protection plate is also suspended by a helicopter, and the protection plate is erected on the support pile on the sloped land with the protection plate leaning on the support pile. Instead of dropping vigorously onto the slope from the air, the guard plate is gently lowered onto the slope and leans against the support pile.
[0010]
That is, both the work of erecting the support pile on the slope and the work of erecting the protection plate on the slope can be performed from the air by the helicopter.
[0011]
A continuous protection plate, which is formed by arranging a large number of protection plates in a row on a slope, prevents the collapse of earth and sand. By providing a large number of such continuous protective plates on the slope, the collapse of earth and sand is reliably prevented.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
[0013]
The method for preventing the collapse of Mt. Fuji according to the present invention is as follows.
[0014]
(1) Manufacture of support pile (see FIGS. 4 and 5)
A large number of support piles 1 are manufactured in advance. Each support pile 1 exposes the lower part 7 of the reinforcing bar 5 in the reinforced concrete column 3 from the lower end 3 a of the column 3, the lower part 7 of the reinforcing bar 5 is provided with a screw 9, and the iron base 11 is A female screw 13 corresponding to the male screw 9 of the lower reinforcing bar 7 is provided, and the base 11 is provided with a pointed tip 15 at a lower portion, and the male screw 9 of the lower reinforcing bar 7 is screwed to the female screw 13 of the base 11. Thus, the base 11 is fixed to the lower end 3a of the column 3.
[0015]
The weight of the iron base 11 is, for example, about ／ of the weight of the entire support pile 1. The angle 17 (see FIG. 5) of the point 15 at the base 11 is, for example, about 30 degrees.
[0016]
It is desirable that the column 3 in the support pile 1 be formed to have a slightly smaller diameter than the base 11 so as to reduce the friction between the column 3 and the earth and sand when the support pile 1 is driven.
[0017]
(2) Production of protective plate (see FIGS. 6 and 7)
A large number of protective plates 21 are manufactured in advance. Each protection plate 21 is provided with a locking portion 25 on the upper edge 23a of the plate-like body 23 made of reinforced concrete. The locking portion 25 is configured such that the reinforcing bar 27 in the plate-like body 23 projects upward from the upper edge 23a of the plate-like body 23 and that the upper end of the reinforcing bar 27 is formed, for example, in an annular shape. In this case, the reinforcing bar 27 having the locking portion 25 at the upper end bends the lower end in the plate-like body 23 to form a bent portion 29, so that the protection plate 21 can be helicopted through the locking portion 25. It is desirable to prevent the rebar 27 from slipping out when suspended. Reference numeral 31 denotes a reinforcing bar other than the reinforcing bar 27 having the locking portion 25 at the upper end.
[0018]
In FIG. 7, an intersection 33 between the vertical reinforcing bar 31 and the horizontal reinforcing bar 31 is bound by an iron wire 34.
[0019]
(3) The support pile 1 is dropped from the air onto the slope 35 by the helicopter standing upright, and the base 11 of the support pile 1 is buried in the ground. It is erected at a predetermined interval on the slope 35 while projecting above the ground.
[0020]
(4) Formation of a continuous protective plate The protective plate 21 is suspended by a helicopter via the locking portion 25, and the protective plate 21 is attached to the support pile 1 above the support pile 1 on the slope 35 (left side in FIG. 2). By standing upright, a large number of protection plates 21 are arranged in a continuous manner on the slope 35 to form a continuous protection plate 38.
[0021]
When the protection plate 21 is hung by a helicopter via the locking portion 25, as an example, a hanging string 39 such as a wire having a hook portion 37 at the lower end is provided on the helicopter, and the hook portion of the hanging string 39 is provided. The locking portion 25 of the protection plate 21 is locked to 37. After the protection plate 21 is leaned on the support pile 1 above the support pile 1 on the slope 35, the hook portion 37 of the hanging string 39 is pulled out from the locking portion 25 of the protection plate 21.
[0022]
It is desirable that the joint 41 between the protective plate 21 and the adjacent protective plate 21 be supported by the support pile 1 as shown in FIG.
[0023]
(5) Multi-stage Arrangement of Continuous Protective Plates The continuous protective plate 38 is provided on the sloping ground 3 in multiple stages in the vertical direction.
[0024]
【The invention's effect】
As described above, according to the present invention, the support pile and the protection plate are manufactured in advance, and the support pile is dropped and erected from the air on a slope by a helicopter at the site, and the protection plate is suspended by the helicopter and supported. Since a large number of continuous protection plates are provided on the slope by leaning on the piles, the time required for the construction is shortened, and the cost required for the construction is also reduced. Furthermore, since the construction at the site is performed by a helicopter, the danger of workers due to the collapse of earth and sand is eliminated.
[Brief description of the drawings]
FIG. 1 is a front view showing a continuous protection plate.
FIG. 2 is a side view showing a state where a plurality of continuous protective plates are provided.
FIG. 3 is a plan view of the same.
FIG. 4 is a sectional view of a support pile dropped on a slope.
FIG. 5 is a sectional view showing a part of the support pile.
FIG. 6 is a sectional view of a suspended protection plate.
FIG. 7 is a front view showing a state in which reinforcing bars of the protection plate are bound by iron wires.
FIG. 8 is a plan sectional view of the protection plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Support pile 3 Column 3a Lower end 5 Rebar 7 Bottom 9 Male screw 11 Base 13 Female thread 15 Sharp end 21 Protective plate 23 Plate 23a Upper edge 25 Locking part 27 Reinforcing rod 29 Bending part 31 Reinforcing rod 33 Intersection 34 Iron wire 35 Inclined ground 37 Hook 38 Continuous protection plate 39 Hanging string 41 Seam

Claims

A lower part of the reinforcing bar in the reinforced concrete column is exposed from a lower end of the column, a screw is provided at a lower portion of the reinforcing bar, and a steel base is provided with a female screw corresponding to an external thread of the lower portion of the reinforcing bar. The base is provided with a pointed tip at the bottom, and a number of support piles are manufactured in advance by fixing the base to the lower end of the column by screwing an external thread of the rebar into an internal thread of the base,
A large number of protective plates, which are provided with locking portions on the upper edge of a reinforced concrete plate, are manufactured in advance,
By dropping the support pile onto the slope from the air with a helicopter and burying the base of the support pile in the ground, a large number of support piles are spaced from the slope at a predetermined interval in a state where the pillars protrude above the ground. Put it up,
Subsequently, the protection plate is suspended by a helicopter via the locking portion, and the protection plate is erected on the support pile on the inclined land on the upper side of the support pile, thereby standing on the inclined land. A large number of protective plates are arranged in a continuous state to form a continuous protective plate,
A method for preventing collapse of Mt. Fuji, comprising providing a plurality of the continuous protective plates on the slope.