JPH07111461B2 - Block displacement measurement method - Google Patents
Block displacement measurement methodInfo
- Publication number
- JPH07111461B2 JPH07111461B2 JP1034743A JP3474389A JPH07111461B2 JP H07111461 B2 JPH07111461 B2 JP H07111461B2 JP 1034743 A JP1034743 A JP 1034743A JP 3474389 A JP3474389 A JP 3474389A JP H07111461 B2 JPH07111461 B2 JP H07111461B2
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- light
- loop
- ground
- fiber loop
- 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.)
- Expired - Lifetime
Links
- 238000006073 displacement reaction Methods 0.000 title claims description 4
- 238000000691 measurement method Methods 0.000 title description 2
- 239000013307 optical fiber Substances 0.000 claims description 36
- 230000033001 locomotion Effects 0.000 claims description 16
- 230000003287 optical effect Effects 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 239000004570 mortar (masonry) Substances 0.000 description 3
- 239000011435 rock Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910001374 Invar Inorganic materials 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Gyroscopes (AREA)
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、断層運動・地すべり運動・なだれ等相互に運
動を行う地塊などの運動を計測する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for measuring movements of a ground block or the like that perform mutual movements such as fault movements, landslide movements, and avalanche movements.
〔従来の技術〕 地震予知・地すべり対策においては、断層や地すべり端
を境界に二つの地塊が相互に行う運動をモニターして、
早期に警報を出すことが重要である。従来はその計測の
為に、地塊同志のある点における相互の運動をインバー
線等を使って計測していた。[Prior art] In earthquake prediction and landslide countermeasures, we monitor the movements of two blocks on the boundary of a fault or landslide edge,
It is important to give an early warning. Conventionally, for the measurement, the mutual movement at a certain point of the earth masses was measured by using the Invar line or the like.
従来の計測方法では選ばれた点における状態のモニター
は出来ても、問題としている断層ある言いすべり帯全体
あるいは広範囲な部分を効率的にモニターすることは不
可能であり、又実際に行うとすれば従来のセンサーを非
常に多く配置するようになり、コストの面でも計測シス
テムの信頼性確保の面でも、多くの問題点が生ずるのは
明らかである。Although it is possible to monitor the condition at the selected point by the conventional measurement method, it is impossible to monitor the entire fault or so-called slip zone or a wide area efficiently, and it is possible to actually monitor it. Therefore, it is obvious that many conventional sensors will be arranged, which causes many problems in terms of cost and ensuring reliability of the measurement system.
本発明は、上記の問題点を解決するものであって、光フ
ァイバージャイロの回転検出機能を生かして、断層全体
あるいは地すべり帯全体を一つのものとしてその変動を
現視できる方法を得ることを目的とする。The present invention is intended to solve the above-mentioned problems, and an object of the invention is to obtain a method in which the rotation detection function of an optical fiber gyro is utilized, and the fluctuation can be visualized as one fault or the entire landslide zone. To do.
本発明は、計測部位に、ずれ変位面を内側に含むように
光ファイバーループを埋め込んで固定すると共に、光フ
ァイバー方向性結合器により光信号を分岐して、光ファ
イバーループの左右両方向に伝播し、光ファイバールー
プを抜け出た光を結合して、２方向の光の位相差を計測
することによって、異なる地塊のすべり速度に比例した
電気信号を取り出し、この電気信号からずれ変位を行う
地塊相互の運動を計測することを特徴とするものであ
る。According to the present invention, an optical fiber loop is embedded and fixed so as to include a displacement surface inside a measurement site, and an optical signal is branched by an optical fiber directional coupler and propagated in both left and right directions of the optical fiber loop. By combining the light that has passed through the space and measuring the phase difference between the light in the two directions, an electrical signal proportional to the slip velocity of different ground blocks is extracted, and the mutual movements of the ground blocks that are displaced from this electrical signal are detected. It is characterized by measuring.
本発明では、光ファイバーループを順逆方向に伝播する
光において、Sagnac効果により伝播路の速度に比例して
生ずる位相差を計測して、相互の運動速度に比例する電
気信号を取り出すものとなっている。光ファイバー内を
順逆方向に伝播する為、光ファイバー内の光伝播特性の
周囲条件依存性をキャンセルするものになっており、又
ファイバーの巻き数・径を選ぶことにより分解能の向上
を計ることができる。In the present invention, in the light propagating in the forward and backward directions through the optical fiber loop, the phase difference generated in proportion to the velocity of the propagation path due to the Sagnac effect is measured, and the electric signal proportional to the mutual motion velocity is extracted. . Since the light propagates in the optical fiber in forward and backward directions, the dependency of light propagation characteristics in the optical fiber on the ambient conditions is canceled, and the resolution can be improved by selecting the number of windings and the diameter of the fiber.
以下、図面を参照しつつ実施例を説明する。 Hereinafter, embodiments will be described with reference to the drawings.
第１図は本発明の１実施例を示す図、第２図は本発明を
実施する装置の回路構成を示す図である。図中、１、２
は異なる地塊に属する岩盤、３は充填用モルタル、４は
光ファイバーループ、５は岩盤に掘ったＵ字形の溝、６
は水平軸、７は断層又は地すべり帯の境界、９は光ファ
イバー方向性結合器、10はビームスプリッター、11は光
源、12は位相差検出器、13はアンプ、14は出力を示す。FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a circuit configuration of an apparatus for carrying out the present invention. 1, 2 in the figure
Are rocks belonging to different blocks, 3 are filling mortars, 4 are optical fiber loops, 5 are U-shaped grooves dug in the rocks, 6
Is a horizontal axis, 7 is a boundary of a fault or a landslide zone, 9 is an optical fiber directional coupler, 10 is a beam splitter, 11 is a light source, 12 is a phase difference detector, 13 is an amplifier, and 14 is an output.
第１図において、光ファイバーループ４は、単一モード
の光ファイバーを用い、断層線７を囲みセンサー部分を
形成する。そして、相互の運動を計測しようとする異な
る地塊の岩盤１、２等の中に埋め込まれる。さらに、周
囲との一体的結合を図る為に膨張性モルタル３を、光フ
ァイバーループ４の周囲に充填する。光ファイバーの周
囲には磁気による影響を防止するため、磁気シールドを
施す場合がある。又溝５の深さは、地中なるべく深く
（１メートル以上）掘り、大気温度の変化の影響が少な
い場所となるようにする。このようにして岩盤１、２等
の中に埋設した光ファイバーループ４を光ファイバージ
ャイロに用い、この光ファイバージャイロでクリープ運
動に起因する地塊１、２の相対運動を計測する。この図
では地塊１が左横ずれ成分を持つ運動を例にしている
が、右横ずれ成分を持つ場合も本質的に変らない。さら
に上下運動でもよい。従って、本発明を実施する装置
は、１つのセンサーで監視すべき全域をカバーするクリ
ープメーターとなる。In FIG. 1, the optical fiber loop 4 uses a single mode optical fiber and surrounds the fault line 7 to form a sensor portion. Then, they are embedded in the rock masses 1, 2 etc. of different blocks, whose mutual movements are to be measured. Further, the expansive mortar 3 is filled around the optical fiber loop 4 in order to achieve an integral connection with the surroundings. A magnetic shield may be provided around the optical fiber to prevent the influence of magnetism. The groove 5 is dug as deep as possible (1 meter or more) in the ground so that the influence of the change in atmospheric temperature is small. The optical fiber loop 4 thus embedded in the bedrocks 1, 2 etc. is used as an optical fiber gyro, and the relative motion of the ground blocks 1, 2 due to the creep motion is measured by this optical fiber gyro. In this figure, the motion of the ground block 1 having a left lateral shift component is taken as an example, but the case where the ground block 1 has a right lateral shift component is essentially unchanged. Further, vertical movement may be performed. The device embodying the invention is therefore a creep meter which covers the whole area to be monitored by one sensor.
次に、参考の為光ファイバー式クリープメーターの動作
を、第２図に示す回路構成で説明する。原理は光ファイ
バージャイロと同じである。Next, for reference, the operation of the optical fiber type creep meter will be described with the circuit configuration shown in FIG. The principle is the same as the optical fiber gyro.
光ファイバー式クリープメーターでは、巻数Ｎの光ファ
イバーループ８を第１図に示すようにして布設する。そ
して、光源11からビームスプリッター10を通して光ファ
イバー方向性結合器９に光信号を送り、光ファイバー方
向性結合器９により光信号を分岐して光ファイバールー
プ８において左右両方向に伝播する。In the optical fiber type creep meter, the optical fiber loop 8 having the number of turns N is laid as shown in FIG. Then, an optical signal is sent from the light source 11 to the optical fiber directional coupler 9 through the beam splitter 10, and the optical signal is branched by the optical fiber directional coupler 9 and propagated in the left and right directions in the optical fiber loop 8.
光ファイバーループ８が断層運動のためにずれると、実
質的には回転したことになり、両まわりの光の間にSagn
ac効果により位相差が生ずる。そこで、この光信号を、
ループを抜け出た後再び光ファイバー方向性結合器９に
より結合した後、ビームスプリッター10を通して光検出
器等の位相差検出器12に入射させ、両方向の光の位相差
を計測する。この位相差信号をアンプ13により増幅する
ことによって出力14が得られる。このようにして光ファ
イバークリープメーターでは、光ファイバーループの軸
方向に沿った平均角速度に比例する信号を検出する。When the optical fiber loop 8 is displaced due to the fault movement, it means that the optical fiber loop 8 is actually rotated, and the Sagn is generated between the light beams around both sides.
A phase difference occurs due to the ac effect. Therefore, this optical signal
After exiting the loop, it is coupled again by the optical fiber directional coupler 9, and then is made incident on the phase difference detector 12 such as a photodetector through the beam splitter 10 to measure the phase difference of light in both directions. The output 14 is obtained by amplifying this phase difference signal by the amplifier 13. In this way, the optical fiber creep meter detects a signal proportional to the average angular velocity along the axial direction of the optical fiber loop.
なお、両回りの光の位相差ΔΦは、ループが円形の場合
には ΔΦ＝Ａω ただし、Ａ＝４πＬf/C2、L:ファイバー長、：ファ
イバーループの平均直径、C:光速、f:光振動周波数であ
る。上記の式から明らかなように感度はループの長さと
平均半径に比例する。When the loop is circular, the phase difference ΔΦ between the two lights is ΔΦ = Aω, where A = 4πLf / C 2 , L: fiber length ,: average diameter of fiber loop, C: speed of light, f: light The vibration frequency. As is clear from the above equation, the sensitivity is proportional to the loop length and the average radius.
以上の説明から明らかなように、本発明によれば、感度
はループの長さと平均半径に比例するので、光ファイバ
ーの巻き数・平均直径を選ぶことにより分解能を理論的
には無限に向上させることができる。また、従来のクリ
ープメーターの欠点である計測の局地性をもカバーし、
目的とする断層又は地すべり帯全体をモニターできる。
さらに、光ファイバーがセンサーであると同時に又信号
の伝達も兼ねている点も上有利であり、センサー部に駆
動部、電気部がないため、メンテナンスが不要で信頼性
が高い。As is clear from the above description, according to the present invention, since the sensitivity is proportional to the loop length and the average radius, it is theoretically possible to improve the resolution infinitely by selecting the number of turns and the average diameter of the optical fiber. You can It also covers the locality of measurement, which is a drawback of conventional creep meters.
The target fault or the entire landslide zone can be monitored.
Further, it is advantageous in that the optical fiber serves as a sensor and also serves as signal transmission. Since the sensor section has no driving section and electric section, maintenance is unnecessary and reliability is high.
第１図は本発明の１実施例を示す図、第２図は本発明を
実施する装置の回路構成を示す図である。 １、２……岩盤、３……充填用モルタル、 ４……光ファイバー、 ５……岩盤に掘ったＵ字溝、 ６……水平軸、７……断層、 ８……光ファイバーループ、 ９……光方向性結合器、 10……ビームスプリッター、 11……光源、12……位相差検出器、 13……アンプ、14……出力。FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a circuit configuration of an apparatus for carrying out the present invention. 1, 2 ... Bedrock, 3 ... Filling mortar, 4 ... Optical fiber, 5 ... U-shaped groove dug in bedrock, 6 ... Horizontal axis, 7 ... Fault, 8 ... Optical fiber loop, 9 ... Optical directional coupler, 10 …… beam splitter, 11 …… light source, 12 …… phase difference detector, 13 …… amplifier, 14 …… output.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 飯高 弘 茨城県つくば市梅園１丁目１番４ 工業技 術院電子技術総合研究所内 (72)発明者 三井 勉 大阪府大阪市此花区島屋１丁目１番３号 住友電気工業株式会社大阪製作所内 (72)発明者 萩原 寿夫 大阪府大阪市此花区島屋１丁目１番３号 住友電気工業株式会社大阪製作所内 (72)発明者 山口 正義 大阪府大阪市此花区島屋１丁目１番３号 住友電気工業株式会社大阪製作所内 審査官 関根 洋之 (56)参考文献 特開 昭59−218903（ＪＰ，Ａ) 特開 昭58−205882（ＪＰ，Ａ) 特開 平１−153918（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Iitaka 1-4-1, Umezono, Tsukuba-shi, Ibaraki Electronic Technology Research Institute, Industrial Technology Institute (72) Inventor Tsutomu Mitsui, 1-1 Shimaya, Konohana-ku, Osaka-shi, Osaka No. 3 Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Toshio Hagiwara 1-3-3 Shimaya, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Electric Industries Ltd. (72) Inventor Masayoshi Yamaguchi Osaka City, Osaka Prefecture Konohana Ward Shimaya 1-3-3 Sumitomo Electric Industries, Ltd. Osaka Works Examiner Hiroyuki Sekine (56) Reference JP 59-218903 (JP, A) JP 58-205882 (JP, A) JP Flat 1-153918 (JP, A)
Claims (1)
に、光ファイバーループを埋め込んで固定すると共に、
光ファイバー方向性結合器により光信号を分岐して、光
ファイバーループの左右両方向に伝播し、光ファイバル
ープを抜け出た光を結合して、２方向の光の位相差を計
測することによって、異なる地塊のすべり速度に比例し
た電気信号を取り出し、この電気信号からずれ変位を行
う地塊相互の運動を計測することを特徴とする地塊変位
計測方法。1. An optical fiber loop is embedded and fixed at a measurement site so as to include a displacement surface inside, and
An optical signal is branched by an optical fiber directional coupler, propagates in both the left and right directions of the optical fiber loop, the light that exits the optical fiber loop is combined, and the phase difference between the light in the two directions is measured, thereby measuring different blocks. A method for measuring the displacement of the ground block, which is characterized by taking out an electric signal proportional to the slip velocity of the ground and measuring the mutual movement of the ground blocks that are displaced from the electric signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1034743A JPH07111461B2 (en) | 1989-02-14 | 1989-02-14 | Block displacement measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1034743A JPH07111461B2 (en) | 1989-02-14 | 1989-02-14 | Block displacement measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02213797A JPH02213797A (en) | 1990-08-24 |
| JPH07111461B2 true JPH07111461B2 (en) | 1995-11-29 |
Family
ID=12422804
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1034743A Expired - Lifetime JPH07111461B2 (en) | 1989-02-14 | 1989-02-14 | Block displacement measurement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07111461B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58205882A (en) * | 1982-05-26 | 1983-11-30 | Fujitsu Ltd | Earthquake sensor |
| JPH0664157B2 (en) * | 1983-05-12 | 1994-08-22 | 綜合警備保障株式会社 | Anomaly detection device using optical fiber |
| JPS61242214A (en) * | 1985-04-16 | 1986-10-28 | Japan Steel & Tube Constr Co Ltd | Distributed landslide detector |
-
1989
- 1989-02-14 JP JP1034743A patent/JPH07111461B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02213797A (en) | 1990-08-24 |
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