JPH0438465A - Method and apparatus for judging liquefaction of ground - Google Patents
Method and apparatus for judging liquefaction of groundInfo
- Publication number
- JPH0438465A JPH0438465A JP2144451A JP14445190A JPH0438465A JP H0438465 A JPH0438465 A JP H0438465A JP 2144451 A JP2144451 A JP 2144451A JP 14445190 A JP14445190 A JP 14445190A JP H0438465 A JPH0438465 A JP H0438465A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- liquefaction
- sensors
- signals
- metal rod
- 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.)
- Granted
Links
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は例えば護岸部周辺地盤の如き、地下水位の高い
砂質地盤よりなる液状化の可能のある地盤の液状化判定
方法及びその装置に係るものである。Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method and apparatus for determining liquefaction of sandy ground with a high groundwater level, such as the ground surrounding a seawall, which is likely to liquefy. This is related.
（従来の技術）
地震時に地盤が液化したか否かを判定するためには、目
視調査による方法と、土圧計及び間隙水圧計、並にそれ
らの増幅器、記録器を使用した計測機器による方法に大
別される。(Prior art) In order to determine whether or not the ground has liquefied during an earthquake, there are two methods: a visual survey, and a method using measurement equipment that uses soil pressure gauges, pore water pressure gauges, their amplifiers, and recorders. Broadly classified.
（発明が解決しようとする課題）
目視調査による方法では、地表面における液状化判定は
可能であるが、地盤内での判定はできない。(Problems to be Solved by the Invention) Although it is possible to determine liquefaction on the ground surface using a visual inspection method, it is not possible to determine liquefaction within the ground.
また土圧計と間隙水圧計を用いる計測機器による方法で
は、土圧力の測定自体が難しいこと、及び液状化の判定
をするには両者の値を比較しなければならないこと、更
に土圧計と間隙水圧計とが設置されている狭い範囲内で
の情報しか得られない。In addition, with methods using measuring instruments that use soil pressure gauges and pore water pressure gauges, it is difficult to measure soil pressure itself, and the values of both must be compared to determine liquefaction. Information can only be obtained within a narrow area where the meter is installed.
本発明は前記従来技術の有する問題点に鑑みて提案され
たもので、その目的とする処は、簡単な構成で早期に、
地盤のどの部分において発生したかを速やかに判定しろ
る地盤の液状化判定方法、及びその装置を提供する点に
ある。The present invention has been proposed in view of the problems of the above-mentioned prior art, and its purpose is to provide an early solution with a simple configuration.
It is an object of the present invention to provide a ground liquefaction determination method and device that can quickly determine in which part of the ground liquefaction has occurred.
（課題を解決するための手段）
前記の目的を達成するため、本発明に係る地盤の液状化
判定方法によれば、液状化の可能性のある地盤内に、２
個所にＡＥセンサーが配設された金属棒を設置し、同両
ＡＨセンサーによって地盤内のＡＥ現象を検出して同地
盤内の液状化を判定するものである。(Means for Solving the Problems) In order to achieve the above object, according to the ground liquefaction determination method according to the present invention, two
Metal rods with AE sensors are installed at certain locations, and both AH sensors detect AE phenomena within the ground to determine liquefaction within the ground.
また本発明に係る地盤の液状化判定装置は、地盤内に設
置された２個所に＾Ｅセンサーが配設された金属棒と、
同各ＡＥセンサーに接続され、同各ＡＥセンサーによる
ＡＥ倍信号検知するとともに、同各ＡＥ倍信号到達時間
差を計測するＡＥ処理装置と、同ＡＥ処理装置の計測デ
ータを人力して演算処理するコンピュータとより構成さ
れている。In addition, the ground liquefaction determination device according to the present invention includes a metal rod installed in the ground and equipped with ^E sensors at two locations;
An AE processing device that is connected to each AE sensor, detects the AE multiplied signals from each AE sensor, and measures the arrival time difference of each AE multiplied signal, and a computer that manually processes the measurement data of the AE processing device. It is composed of.
（作用）
地震時に地盤に作用している土圧と間隙水圧とが等しく
なった場合、土粒子はその土庄と水圧とがバランスして
いるために浮いている状態、即ち液状化状態となる。こ
の場合、土粒子と水の動きが生起して、これに伴って音
のエネルギが放出されるＡＥ現象（アコースティックエ
ミッション、Ａｃｏｕｓｔｉｃ Ｅｍｉｓｓｉｏｎ）が
生起する。(Operation) When the earth pressure acting on the ground during an earthquake becomes equal to the pore water pressure, the soil particles are in a floating state, that is, in a liquefaction state, because the soil pressure and water pressure are in balance. In this case, movement of soil particles and water occurs, resulting in an AE phenomenon (acoustic emission) in which sound energy is released.
これに伴って前記したように地盤内に設置された金属棒
の２個所に配設されたＡＥセンサーが前記ＡＥ現象を検
出し、同ＡＥ現象を検出したときの音の波形パラメータ
と、両センサーのＡＨ到達時間差と、金属棒を伝わる音
速とを計測することによって、地盤内の液状化を判定す
ることができる。Along with this, as mentioned above, the AE sensors installed at two locations on the metal rod installed in the ground detect the AE phenomenon, and the waveform parameters of the sound when the AE phenomenon is detected, and the sound waveform parameters of both sensors. Liquefaction in the ground can be determined by measuring the AH arrival time difference and the sound speed transmitted through the metal rod.
本発明によればこのように、ＡＥセンサーが土粒子と水
の微小な動きによる音を検出することができることによ
って、液状化の初期段階を的確に捕捉することができる
。According to the present invention, since the AE sensor can detect the sound caused by minute movements of soil particles and water, it is possible to accurately detect the initial stage of liquefaction.
（実施例） 以下本発明を図示の実施例について説明する。(Example) The present invention will be described below with reference to the illustrated embodiments.
（２）は護岸部（８周辺の地下水位置が高く、液状化現
象の生起する可能性の高い砂質地盤で、同砂質地盤（２
）に上下方向に間隔を存してＡＥセンサー（１）が配設
された、音を良好に伝達する金属棒（２）（ウェーブガ
イド）が設置されている。(2) is a sandy ground with a high groundwater level around the seawall (8) and a high possibility of liquefaction occurring;
) is provided with a metal rod (2) (waveguide) that transmits sound well and has AE sensors (1) arranged at intervals in the vertical direction.
前記各ＡＥセンサー（１）は夫々ケーブル（３）を介し
てＡＥ処理装！（４）に接続され、更に同ＡＥ処理装置
（４）はケーブル（３）を介してコンピュータ（５）に
接続されている。Each of the AE sensors (1) is connected to an AE processing device via a cable (3). (4), and the AE processing device (4) is further connected to a computer (5) via a cable (3).
而して地震時において前記地盤（２）が液状化し、土粒
子と水の動きが生じてＡＥ現象が生起すると、前記ＡＥ
センサー（１）によってこれを検出し、同ＡＨセンサー
（１）による検出信号をＡＥ倍信号ノイズかを判別して
、＾Ｅ信号のみを取出してＡＥ処理装置（４）に入力し
、同＾Ｅセンサー処理装置によって前記両ＡＥセンサー
（］）からのＡＨ信号到達時間差や、金属棒（２）を伝
わる音速、ＡＥ倍信号検出したときの音の波形パラメー
ターを計測し、前記ＡＥ処理装置（４）の計測データを
コンピュータ（５）に入力、演算し、地盤内の液状化を
判定する。Therefore, when the ground (2) liquefies during an earthquake and movement of soil particles and water occurs, causing an AE phenomenon, the AE phenomenon occurs.
The sensor (1) detects this, determines whether the detection signal from the AH sensor (1) is AE multiplied signal noise, extracts only the ^E signal, inputs it to the AE processing device (4), and processes the same ^E signal. The sensor processing device measures the difference in arrival time of the AH signals from the two AE sensors (]), the speed of sound traveling through the metal rod (2), and the waveform parameters of the sound when the AE multiplied signal is detected, and the AE processing device (4) The measured data is input to the computer (5) and calculated, and liquefaction in the ground is determined.
而して前記ＡＥセンサー（１）は土粒子と水との微小な
動きによる音を検出することができるので、地盤＾の液
状化の初期段階を的確に捕えることができる。Since the AE sensor (1) can detect the sound caused by minute movements between soil particles and water, it can accurately detect the initial stage of liquefaction of the ground.
かくして前記地盤内の液状化が判定されると、周辺域に
配置された揚水設備に前記コンピュータ（５）より指令
を発して作動せしめ、地下水位の低下を図り、液状化の
進行を早期に食い止める液状化防止策が可能となる。In this way, when liquefaction in the ground is determined, the computer (5) issues a command to the pumping equipment located in the surrounding area and activates it to lower the groundwater level and stop the progress of liquefaction at an early stage. It becomes possible to take measures to prevent liquefaction.
（発明の効果）
本発明に係る地盤の液状化判定方法によれば前記したよ
うに、液状化の可能性のある地盤内に、２個所にＡＥセ
ンサーが配設された金属棒を設置し、同両ＡＥセンサー
によって地盤内のＡＥ現象を検出して、同地盤内の液状
化を早期に判定して、地盤の液状化の進行を早期に食い
止める有効な液状化防止対策を講することが可能となる
。(Effects of the Invention) According to the ground liquefaction determination method according to the present invention, as described above, a metal rod with AE sensors arranged at two locations is installed in the ground that has a possibility of liquefaction, Both AE sensors can detect AE phenomena in the ground, determine liquefaction in the ground at an early stage, and take effective liquefaction prevention measures to stop the progression of ground liquefaction at an early stage. becomes.
請求項２の発明は、地盤内に設置され、且つ２個所にＡ
Ｅセンサーが配設された金属棒と、同各ＡＥセンサーに
接続され、同各ＡＥセンサーによるＡＥ倍信号検知する
とともに、同各ＡＥ倍信号到達時間差を計測するＡＥ処
理装置と、同Ａｌｌ！処理装置の計測データを入力して
演算処理するコンピュータとによって、前記地盤の液状
化判定方法を効果的に遂行することができる地盤の液状
化判定装置を提供するものである。The invention of claim 2 is installed in the ground, and has A at two locations.
A metal rod on which an E sensor is arranged, an AE processing device connected to each of the same AE sensors, which detects the AE multiplied signal from each of the same AE sensors, and measures the difference in arrival time of each of the same AE multiplied signals, and the same All! The present invention provides a ground liquefaction determination device that can effectively carry out the ground liquefaction determination method using a computer that inputs measurement data from a processing device and performs arithmetic processing.
第１図は本発明に係る地盤の液状化判定方法の一実施例
の実施状況を示す概略図である。
（２）・・・砂質地盤、 （１）・・・ＡＥセンサ
ー（２）・・・金属棒、 （４）・・・ＡＥ処理
装置、（５）・・・コンピュータ。
代理人 弁理士 岡 本 重 文
外１名
第１図FIG. 1 is a schematic diagram showing the implementation status of an embodiment of the ground liquefaction determination method according to the present invention. (2)...Sandy ground, (1)...AE sensor (2)...Metal rod, (4)...AE processing device, (5)...Computer. Agent: Patent attorney Shige Okamoto (1 person) Figure 1
Claims (2)
ンサーが配設された金属棒を設置し、同両ＡＥセンサー
によって地盤内のＡＥ現象を検出して同地盤内の液状化
を判定することを特徴とする地盤の液状化判定方法。(1) A metal rod with AE sensors installed at two locations is installed in the ground that has the potential for liquefaction, and both AE sensors detect AE phenomena in the ground, causing liquefaction in the same ground. A ground liquefaction determination method characterized by determining.
された金属棒と、同各ＡＥセンサーに接続され、同各Ａ
ＥセンサーによるＡＥ信号を検知するとともに、同各Ａ
Ｅ信号の到達時間差を計測するＡＥ処理装置と、同ＡＥ
処理装置の計測データを入力して演算処理するコンピュ
ータとよりなることを特徴とする地盤の液状化判定装置
。(2) A metal rod with AE sensors installed in two places installed in the ground, and a metal rod connected to each AE sensor and each A
In addition to detecting the AE signal from the E sensor, each A
An AE processing device that measures the arrival time difference of E signals, and an AE processing device that measures the arrival time difference of the E signal.
A ground liquefaction determination device comprising a computer that inputs measurement data from a processing device and performs arithmetic processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2144451A JP2543778B2 (en) | 1990-06-04 | 1990-06-04 | Ground liquefaction prevention device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2144451A JP2543778B2 (en) | 1990-06-04 | 1990-06-04 | Ground liquefaction prevention device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0438465A true JPH0438465A (en) | 1992-02-07 |
| JP2543778B2 JP2543778B2 (en) | 1996-10-16 |
Family
ID=15362547
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2144451A Expired - Fee Related JP2543778B2 (en) | 1990-06-04 | 1990-06-04 | Ground liquefaction prevention device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2543778B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5526290B1 (en) * | 2013-04-02 | 2014-06-18 | 報国エンジニアリング株式会社 | Sampling apparatus and method for liquefaction determination |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6283685A (en) * | 1985-10-09 | 1987-04-17 | Tokyu Constr Co Ltd | Method for measuring ae in ground |
-
1990
- 1990-06-04 JP JP2144451A patent/JP2543778B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6283685A (en) * | 1985-10-09 | 1987-04-17 | Tokyu Constr Co Ltd | Method for measuring ae in ground |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5526290B1 (en) * | 2013-04-02 | 2014-06-18 | 報国エンジニアリング株式会社 | Sampling apparatus and method for liquefaction determination |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2543778B2 (en) | 1996-10-16 |
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