JPH0443989A - Method and instrument for measuring elastic wave speed - Google Patents
Method and instrument for measuring elastic wave speedInfo
- Publication number
- JPH0443989A JPH0443989A JP2149789A JP14978990A JPH0443989A JP H0443989 A JPH0443989 A JP H0443989A JP 2149789 A JP2149789 A JP 2149789A JP 14978990 A JP14978990 A JP 14978990A JP H0443989 A JPH0443989 A JP H0443989A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- elastic wave
- elastic
- wave
- casing pipe
- 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
- 238000000034 method Methods 0.000 title claims description 10
- 230000010356 wave oscillation Effects 0.000 claims description 20
- 230000000149 penetrating effect Effects 0.000 claims description 9
- 230000001902 propagating effect Effects 0.000 claims description 6
- 238000005259 measurement Methods 0.000 abstract description 8
- 230000000644 propagated effect Effects 0.000 abstract description 2
- 230000035939 shock Effects 0.000 abstract description 2
- 239000011435 rock Substances 0.000 description 7
- 230000005284 excitation Effects 0.000 description 5
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000004809 Teflon Substances 0.000 description 2
- 229920006362 Teflon® Polymers 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 238000009527 percussion Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は弾性波による地盤調査に用いる弾性波速度計測
方法及びそれを実施する装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an elastic wave velocity measuring method used for ground investigation using elastic waves, and an apparatus for carrying out the method.
更に詳述すると、本発明は地盤中を伝播する弾性波の直
接波の伝播速度から地盤等の探査を行なう弾性波速度計
測方法及びその装置に関する。More specifically, the present invention relates to an elastic wave velocity measuring method and apparatus for investigating the ground based on the propagation velocity of a direct elastic wave propagating in the ground.
（従来の技術）
弾性波による地盤調査の１つとして、地中において横坑
やポーリング孔を利用して直接波の伝播速度を測定して
岩盤の良否の判定や岩盤分類の一指標とするものがある
。この弾性波による調査は物理探査法の中で最も汎用性
があり通常の岩盤調査に用いられている。(Conventional technology) As a type of ground investigation using elastic waves, the propagation speed of waves is directly measured underground using a shaft or a polling hole, and this is used as an indicator for determining the quality of the rock mass and for classifying the rock mass. There is. This survey using elastic waves is the most versatile of the geophysical survey methods and is used for ordinary rock surveys.
従来の弾性波探査は、地表又は地中の一点で爆発等によ
って人工的に衝撃を与え、地盤・岩盤を振動させ、発生
した弾性波が周囲に広がっていく際の波動の速度を検出
して岩盤の物理的性質等を調査するものである０弾性波
の速度は蝋質である地盤や岩盤の物理的性質に左右され
ることから、弾性波の伝播速度から岩盤の適否判断、掘
削線の決定、岩盤の緩み、領域の判定、グラウト効果の
判定等を行なうことができるし、また弾性波速度を原位
置試験に対する分類上の指標としても用いられる。Conventional elastic wave exploration involves applying an artificial shock, such as an explosion, at a point on the ground surface or underground, causing the ground/rock to vibrate, and then detecting the speed of the generated elastic waves as they spread to the surrounding area. The speed of the zero elastic wave, which is used to investigate the physical properties of rock, is affected by the waxy ground and the physical properties of the rock. The elastic wave velocity can be used as a classification indicator for in-situ testing.
この弾性波による探査は縦波（Ｐ波）と横波（Ｓ波）を
使用して行われている０例えば、横坑内の爆破点からの
直接波を他の横坑内に設けた幾つかの受振点で受けてそ
の間の弾性波速度を多数測定して岩盤のゾーン区分とそ
の平均速度を求めることがあり、またある間隔で数本の
ポーリング孔内部にその深さに応じて側線を求め、直接
波定時曲線を求めて深度に応じた速度を求めることもあ
る。This exploration using elastic waves is carried out using longitudinal waves (P waves) and transverse waves (S waves). In some cases, the zonal division of the rock and its average velocity can be determined by measuring the elastic wave velocity at a number of points, and the lateral lines are determined according to the depth inside several poling holes at certain intervals, and the lateral lines are measured directly. Sometimes, a wave time curve is obtained to determine the speed depending on the depth.
（発明が解決しようとする８Ｂ”）
しかしながら、従来の探査方法はいずれも地表面に弾性
波発振源を設けるか、あらがしめポーリング孔を開けて
その孔の中に弾性波の発振源と受振器とを備えて探査す
るようにしているので、弾性波発振源を地表面に設置で
きないような調査例えば海底地質や海底地盤の調査にお
いては使用できなかった。また、ポーリング孔を使用し
て弾性波探査を行う場合にはポーリング孔をあらかじめ
設けるための時間とコストがかかるし、砂地のような柔
らかい地盤では実施できない、特に、２本の縦坑を組合
せることによって深度方向の弾性波速度を測定すること
も可能であるが、複雑なポーリングを必要とするなめ費
用がかさむ上に弾性波発振源と弾性波受振器の距離が一
定でないため測定精度が充分にでない問題がある。また
、縦坑を利用した弾性波探査では地盤の深度方向の弾性
波速度が計測できないため詳細な地盤の速度構造が得ら
れない。(8B to be solved by the invention) However, in all conventional exploration methods, an elastic wave oscillation source is provided on the ground surface, or a poling hole is drilled and an elastic wave oscillation source is placed inside the hole. This method cannot be used in surveys where it is not possible to install an elastic wave oscillation source on the ground surface, such as surveys of seabed geology or seabed soil. When conducting wave exploration, it takes time and cost to prepare polling holes in advance, and it cannot be carried out on soft ground such as sand. Although measurement is possible, it requires complicated polling, which increases the cost of licking, and the distance between the elastic wave oscillation source and the acoustic wave geophone is not constant, so the measurement accuracy is insufficient. Elastic wave exploration using a pit cannot measure the elastic wave velocity in the depth direction of the ground, so detailed ground velocity structures cannot be obtained.
本発明は測定精度が良く深度方向に連続して弾性波速度
が測定できかつ調査費用が安価につく弾性波速度計測方
法及びその装置を捷供することを目的とする。SUMMARY OF THE INVENTION An object of the present invention is to provide an elastic wave velocity measuring method and apparatus that have good measurement accuracy, can measure elastic wave velocity continuously in the depth direction, and are inexpensive to investigate.
（課題を解決するための手段）
かかる目的を達成するため、本発明の弾性波速度計測方
法は、弾性波による調査を行う地盤に弾性波受振器と地
盤を伝播する弾性波の速度を測定する２個の受振器とを
１本のパイプに収めて地盤に貫入し、前記弾性波発振源
から発振される弾性波が地盤中を伝播するＳ波速度を前
記２個の受振器の波動到達時間差から求め、前記パイプ
を貫入して深度方向に連続的にＳ波速度を求めるように
している。(Means for Solving the Problems) In order to achieve the above object, the elastic wave velocity measurement method of the present invention includes an elastic wave geophone attached to the ground to be investigated using elastic waves, and the velocity of elastic waves propagating through the ground is measured. The two geophones are housed in one pipe that penetrates the ground, and the S-wave velocity at which the elastic wave oscillated from the elastic wave oscillation source propagates in the ground is determined by the wave arrival time difference between the two geophones. The S-wave velocity is determined continuously in the depth direction by penetrating the pipe.
また、本発明の弾性波速度計測装置は、地中に貫入可能
なケーシングパイプと、このパイプ内に収容されると共
に一部がケーシングパイプの外に突出した加振部材を有
する弾性波発振源と、地盤中を伝播する弾性波のＳ波速
度を測定する受振器とから成り、前記受振器は深度方向
に一定間隔を開けて２個配置するようにしている。Further, the elastic wave velocity measuring device of the present invention includes a casing pipe that can penetrate into the ground, and an elastic wave oscillation source that is housed in the pipe and has an excitation member that partially protrudes outside the casing pipe. , and a geophone for measuring the S-wave velocity of elastic waves propagating in the ground, and two of the geophones are arranged at a constant interval in the depth direction.
（作用）
したがって、ケーシングパイプを地盤内に貫入すること
によって弾性波発振源と受振器とを一定の間隔をあけて
地中にａ置し、弾性波速度測定を実施することができる
０弾性波発振源から与えられたＳ波は地盤を伝わって深
度方向に伝播し２個の受振器によってそれぞれ検出され
る。この２個の受振器に到達するＳ波の到達時間差とこ
れら受振器間の距離とからＳ波速度が求められる。また
、その深度における弾性波探査が終了した後、更にケー
シングパイプを貫入して探査深度を変えつつ弾性波によ
る探査を繰返すことによって深度方向のＳ波の速度を連
続的に求める。(Function) Therefore, by penetrating the casing pipe into the ground, the elastic wave oscillation source and the geophone are placed underground at a certain distance, and elastic wave velocity measurement can be performed. The S wave given from the oscillation source propagates through the ground in the depth direction and is detected by two geophones. The S-wave velocity is determined from the arrival time difference of the S-waves reaching these two geophones and the distance between these geophones. After the elastic wave exploration at that depth is completed, the casing pipe is further penetrated and the exploration using elastic waves is repeated while changing the exploration depth to continuously determine the velocity of the S wave in the depth direction.
（実施例）
以下、本発明の構成を図面に示す実施例に基づいて＃細
に説明する。(Example) Hereinafter, the configuration of the present invention will be described in detail based on an example shown in the drawings.
第１図に本発明の弾性波速度計測装置の原理図を示す、
この弾性波速度計測装置は、先端にコーン２を有するケ
ーシングパイプ１とこの中に設置されている弾性波発振
源３と２個の受振器４．５と先端抵抗を検出する荷重計
６とから構成されており、上部の弾性波発振源３から地
盤に加えられた弾性波のＳ波速度を２個の受振器４．５
で測定し、各受振器４．５の間の弾性波到達時間差から
弾性波速度を求めるようにしている。FIG. 1 shows a principle diagram of the elastic wave velocity measuring device of the present invention.
This elastic wave velocity measuring device consists of a casing pipe 1 having a cone 2 at its tip, an elastic wave oscillation source 3 installed inside the casing pipe, two geophones 4.5, and a load cell 6 for detecting tip resistance. The S-wave velocity of the elastic wave applied to the ground from the upper elastic wave oscillation source 3 is detected by two geophones 4.5.
The elastic wave velocity is determined from the difference in arrival time of elastic waves between each geophone 4.5.
ケーシングパイプ１は地盤に貫入できる程度の強度を要
すれば足りるが、一般には鋼管が採用される。このケー
シングパイプ１の先端には地盤への貫入を容易にするた
め、コーン２が設けられている。このコーン２の先端の
角度は例えば６０゜程度に設定されている。The casing pipe 1 only needs to have enough strength to penetrate the ground, but generally a steel pipe is used. A cone 2 is provided at the tip of the casing pipe 1 to facilitate penetration into the ground. The angle of the tip of this cone 2 is set to, for example, about 60°.
先端抵抗計測用荷重計６は貫入時にケーシングパイプ１
の先端にかかる地盤の強さを求めるためのもので、コー
ン２にかかる先端抵抗（土圧）から地盤の硬さ・強さを
求め、Ｓ波速度との数値的関係を求めるデータとして利
用するようにしている。The load cell 6 for measuring tip resistance is connected to the casing pipe 1 during penetration.
This is used to determine the strength of the ground applied to the tip of cone 2.The hardness and strength of the ground is determined from the resistance (earth pressure) applied to the tip of cone 2, and is used as data to calculate the numerical relationship with the S-wave velocity. That's what I do.
弾性波発振源３は、例えば第２図の詳細図に示すように
、正逆回転モータ７と、弾性波を発生させ地盤に与える
加振部材８と、この加振部材８に衝撃を与える回転ハン
マー９と、この回転ハンマー９と正逆回転モータ７とを
連結し回転力を伝播するフォーク１０とから構成されて
いる。正逆回転モータ７は地上の制御装置（図示省略）
からの指示にようへて正回転と逆回転とを行なう、尚、
モータには減速ギア１１が内蔵されており、低速回転で
回転出力が得られるように設けられている。As shown in the detailed view of FIG. 2, the elastic wave oscillation source 3 includes, for example, a forward and reverse rotation motor 7, an excitation member 8 that generates elastic waves and applies them to the ground, and a rotating motor that applies an impact to the excitation member 8. It is composed of a hammer 9 and a fork 10 that connects the rotary hammer 9 and a forward/reverse rotary motor 7 to transmit rotational force. The forward/reverse rotation motor 7 is a control device on the ground (not shown)
Perform forward and reverse rotation according to the instructions from
The motor has a built-in reduction gear 11, and is provided so that rotational output can be obtained at low speed rotation.
モータ７と回転ハンマー９とはフォーク１０を介して連
結されており、モータ７によって回転するフォーク１０
がハンマー９を挟持して回転させるように設けられてい
る。一方、ハンマー９はケーシングパイプ１に固着され
ている板ばね１２にピン２５を介して当接し、この板ば
ね１２によってその回転が一時的に阻止されるように設
けられている。したがって、回転エネルギーが板ばね１
２に蓄えられ、尚も回転を続けることによってハンマー
９が板ばね１２から外れたときにハンマー９がフォーク
１０から離れて自由回転をし加振部材８の一部である打
撃棒１４あるいは１５を勢いよく打撃するように設けら
れている。打撃方向の切替えは地上のスイッチ（図示省
略）の切り替えによってモータ７の回転方向を切替える
ことによって行なわれる。加振部材８を介して地盤に右
回転と左回転の打撃を加えることによって地盤内に波形
が互いに逆転しなＳ波を発生させる。ハンマー９はケー
シングパイプ１内の中心に回転自在に設置されている１
例えば、ケーシングパイプｌ内に固着された隔壁板１６
にハンマー９の回転軸１７をケーシングパイプ１と同心
状に固着し、該軸１７にハンマー９を回転自在に取付け
ている。The motor 7 and the rotary hammer 9 are connected via a fork 10, and the fork 10 is rotated by the motor 7.
is provided so as to grip and rotate the hammer 9. On the other hand, the hammer 9 is provided so that it comes into contact with a leaf spring 12 fixed to the casing pipe 1 via a pin 25, and its rotation is temporarily prevented by the leaf spring 12. Therefore, the rotational energy of leaf spring 1
2, and by continuing to rotate, when the hammer 9 comes off the leaf spring 12, the hammer 9 separates from the fork 10 and rotates freely, causing the striking rod 14 or 15, which is a part of the vibrating member 8, to move. It is designed to strike with force. The direction of impact is changed by switching the direction of rotation of the motor 7 by switching a switch on the ground (not shown). By applying clockwise and counterclockwise impacts to the ground via the vibrating member 8, S waves whose waveforms are reversed are generated in the ground. The hammer 9 is rotatably installed in the center of the casing pipe 1.
For example, the partition plate 16 fixed inside the casing pipe l
A rotary shaft 17 of the hammer 9 is fixed concentrically to the casing pipe 1, and the hammer 9 is rotatably attached to the shaft 17.
また、ケーシングパイプ１の外周面にはケーシングパイ
プ１内のハンマー９によって打撃され弾性波を地盤に伝
達する加振部材８が設けられている。この加振部材８と
しては、本実施例の場合、歯車状のリングが採用されて
いる。歯車状リングだと地盤への貫入時の抵抗がフラン
ジに比べて週かに小さいにもかかわらず、加振時には歯
面の間の土にも振動を与え環状フランジと同じＳ波を得
ることができる。このリング８はハンマー９による打撃
力をケーシングパイプ１の周囲の地盤に伝達するための
もので、ケーシングパイプ１の外周に設置されると共に
その一部の打撃棒１４．１５がケーシングパイプ１内に
突出し、ハンマー９の回転軌跡上に位置するように設け
られている。歯車状リング８はケーシングパイプｌの外
周面に形成された環状溝１８内に収容され、打撃棒１４
゜１５部分がケーシングパイプ１を貫通する孔１９を通
ってケーシングパイプ１内に突出している。Furthermore, a vibrating member 8 is provided on the outer peripheral surface of the casing pipe 1 and is struck by a hammer 9 inside the casing pipe 1 to transmit elastic waves to the ground. In this embodiment, a gear-shaped ring is used as the vibrating member 8. Even though the resistance when penetrating into the ground with a gear-shaped ring is slightly smaller than that of a flange, it is possible to vibrate the soil between the tooth surfaces during excitation and obtain the same S wave as an annular flange. can. This ring 8 is for transmitting the striking force of the hammer 9 to the ground around the casing pipe 1, and is installed around the outer circumference of the casing pipe 1, and a part of the striking rod 14, 15 is inserted into the casing pipe 1. It protrudes and is provided so as to be located on the rotation locus of the hammer 9. The gear-shaped ring 8 is housed in an annular groove 18 formed on the outer circumferential surface of the casing pipe l, and is inserted into the striking rod 14.
15 portion projects into the casing pipe 1 through a hole 19 passing through the casing pipe 1.
この歯車状リング８とケーシングパイプ１との間には０
リング２０及びテフロン（テトラフルオロエチレン）製
のシート状ワッシャ２１などの制振材料を介在して振動
がケーシングパイプｌに伝播されるのを防いでいる。Ｆ
ｉ動の遮断は上述の０リング２０やテフロン製ワッシャ
２１などに限定されず、他の割振材料やエラストマー材
の使用も可能である。Between this gear-shaped ring 8 and the casing pipe 1, there is no
Vibration is prevented from being propagated to the casing pipe l by interposing vibration damping materials such as a ring 20 and a sheet washer 21 made of Teflon (tetrafluoroethylene). F
I-motion isolation is not limited to the above-mentioned O-ring 20 or Teflon washer 21, but other distribution materials or elastomer materials can also be used.
第１図に示すように、上述の弾性波発振源３よりも先端
側には２個の受振器４．５が内蔵されている０例えば、
ケーシングパイプ１の外周面に形成された環状溝２２部
に防振ゴム２３を介在させて塩化ビニルのパイプ２４を
装着し、該パイプ２４に受振器４，５を固定し、地盤を
伝播する弾性波の振動振動を検出するように設けられて
いる。As shown in FIG. 1, two geophones 4.5 are built in on the tip side of the elastic wave oscillation source 3 described above.
A vinyl chloride pipe 24 is attached to the annular groove 22 formed on the outer peripheral surface of the casing pipe 1 with a vibration isolating rubber 23 interposed therebetween, and the vibration receivers 4 and 5 are fixed to the pipe 24 to reduce the elasticity that propagates through the ground. It is arranged to detect vibrational vibrations of waves.
尚、受振器４．５はケーシングパイ１１の貫通孔２６を
通過してパイプ２４に固着されている。ケーシングパイ
プ１の一部を塩化ビニールのパイプ２４に１換するのは
、鋼管から成るケーシングパイプ１を伝わる打撃の雑音
を遮断するためであり、特に塩化ビニール製パイプに限
定されるものではなく、Ｓ波の伝達速度がケーシングパ
イプ１と違う材質のものを採用すれば足りる。受振器４
，５としては一般に速度ピックアップあるいは加速度ピ
ックアップが採用される。尚、本実施例では貫入時の抵
抗を小さくするために、ケーシングパイプ１と塩化ビニ
ールパイプ２４とが面一となるようにほぼ同じ外径のパ
イプに設けられているが、特にこれに限定されるもので
はなく、ケーシングパイプ１に対して受振器４．５を取
付けなパイプ２４を僅かに大径ないし小径とすることも
可能である。Note that the geophone 4.5 passes through the through hole 26 of the casing pipe 11 and is fixed to the pipe 24. The reason why a part of the casing pipe 1 is replaced with a vinyl chloride pipe 24 is to block the noise of impact transmitted through the casing pipe 1 made of a steel pipe, and is not limited to a pipe made of vinyl chloride. It is sufficient to use a material whose S wave transmission speed is different from that of the casing pipe 1. Geophone 4
, 5 are generally speed pickups or acceleration pickups. In this embodiment, in order to reduce the resistance during penetration, the casing pipe 1 and the vinyl chloride pipe 24 are provided on pipes having approximately the same outer diameter so as to be flush with each other, but the present invention is not particularly limited to this. It is also possible to attach the vibration receiver 4.5 to the casing pipe 1 and to make the pipe 24 have a slightly larger or smaller diameter.
尚、上述の実施例は本発明の好適な実施の一例ではある
がこれに限定されるものではなく本発明の要旨を逸脱し
ない範囲において種々変形実施可能である０例えば、加
振部材８としては歯車状リングに特に限定されず、セレ
ーション形状やスプライン形状、ピン形状あるいは環状
フランジ形状であっても良い、また、本実施例では左右
方向に打撃回転を与えることによって波形を反転させ、
Ｓ波であることの確認を行なっているが、特にこれに限
定されるものではなくＳ波の確認が他の方法でとれるの
であれば一方向の回転打撃だけでも実施可能である。勿
論、本発明をＳ波よりも測定が容易なＰ波の速度測定に
使用できることはいうまでもない。Although the above-mentioned embodiment is an example of a preferred implementation of the present invention, it is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, as the vibrating member 8, The ring is not particularly limited to a gear-like ring, and may have a serration shape, a spline shape, a pin shape, or an annular flange shape.In this embodiment, the waveform is reversed by applying impact rotation in the left and right direction,
Although we have confirmed that it is an S wave, the present invention is not particularly limited to this, and if the S wave can be confirmed by other methods, it can be carried out using only one-directional rotational impact. Of course, it goes without saying that the present invention can be used to measure the velocity of P waves, which are easier to measure than S waves.
更に、弾性波発振源３としては上述のモータ７と打撃ハ
ンマー９と歯車状リング８との組合せに限定されず、他
の発振源例えば爆発物による弾性波の発生を採用するこ
とも可能である。また、２個の受振器のうちの１個を弾
性波発振源に設け、弾性波発生から他の受振器到達まで
の時間からＳ波速度を求めることも可能である。Furthermore, the elastic wave oscillation source 3 is not limited to the above-mentioned combination of the motor 7, percussion hammer 9, and gear-shaped ring 8, but other oscillation sources such as generation of elastic waves by explosives can also be used. . It is also possible to provide one of the two geophones as an elastic wave oscillation source and determine the S-wave velocity from the time from generation of the elastic wave to arrival at the other geophone.
以上のように構成したので、次のようにして弾性波によ
る探査が行なわれる。まず、探査対象たる地盤の地表か
らケーシングパイプ１を測定しようとする深度まで、ボ
ーリングロッド（図示省略）を介して油圧シリンダ（図
示省略）で貫入する。With the configuration as described above, exploration using elastic waves is performed as follows. First, a hydraulic cylinder (not shown) is used to penetrate the casing pipe 1 from the ground surface to the depth to be measured via a boring rod (not shown).
そして、地上からの操作によって正逆回転モータ７を回
転させ、モータ７の回転によって駆動されるフォーク１
０がハンマー９を挾持して正転方向（第４図上反時計回
転方向）に回転させる。このとき、ケーシングパイプ１
の板ばね１２によってハンマー９の回転が阻止されてい
るため回転エネルギーが板ばね１２に蓄えられる。そし
て、更に回転を続けることによってハンマー９が板ばね
１２から外れて打撃棒１４を勢いよく打撃する。この打
撃によって歯車状リング８に弾性波が生じ、ケーシング
パイプ１の外の歯面８ａ部分を中心に地盤に振動を与え
る。一方の打撃終了後、スイッチの切り替えによってモ
ータ７を逆回転させ、反対側の打撃棒１５を同様にして
ハンマー９で打撃し逆回転の弾性波即ちＳ波を地盤に与
える。歯車状リング８を介して地盤に右回転と左回転の
打撃を交互に加えて地盤内に波形が反転した２個のＳ波
を発生させる。この波形が反転した２つの弾性波を受振
器４．５によってそれぞれ検出することによって、Ｓ波
であることを確認すると共に各受振器４．５への波動到
達時間差と受振器４．５間の距離から地盤内を伝播する
弾性波速度を求める。Then, the forward and reverse rotation motor 7 is rotated by an operation from the ground, and the fork 1 is driven by the rotation of the motor 7.
0 grips the hammer 9 and rotates it in the forward rotation direction (counterclockwise rotation direction in the top of FIG. 4). At this time, casing pipe 1
Since rotation of the hammer 9 is prevented by the leaf spring 12, rotational energy is stored in the leaf spring 12. Then, as the rotation continues, the hammer 9 comes off the leaf spring 12 and hits the striking rod 14 with force. This impact generates elastic waves in the gear-like ring 8, which vibrates the ground around the outer tooth surface 8a of the casing pipe 1. After one impact is completed, the motor 7 is reversely rotated by switching a switch, and the opposite impact rod 15 is similarly impacted with the hammer 9 to apply a reversely rotated elastic wave, ie, an S wave, to the ground. Two S waves with reversed waveforms are generated in the ground by alternately applying clockwise and counterclockwise strikes to the ground via a gear ring 8. By detecting the two elastic waves whose waveforms are inverted by the geophones 4.5, it is confirmed that they are S waves, and the difference in wave arrival time to each geophone 4.5 and the difference between the waves between the geophones 4.5 and 4.5 are confirmed. Find the velocity of elastic waves propagating in the ground from the distance.
波動到達時間差は測定波形のピークからビークの時間を
求めることによって得られる。このとき、各受振器４，
５の測定信号を対照することによってケーシングパイプ
１などを伝わるノイズを除去できる。The wave arrival time difference is obtained by determining the peak to peak time of the measured waveform. At this time, each geophone 4,
By comparing the measurement signals of 5, noise transmitted through the casing pipe 1 and the like can be removed.
斯様にケーシングパイプ１を地盤中に貫入させながら深
度方向に連続的にＳ波速度を求めることによって地盤内
各地層のＳ波速炭分布を詳細に求められる。In this way, by penetrating the casing pipe 1 into the ground and continuously determining the S-wave velocity in the depth direction, the S-wave velocity coal distribution in each stratum within the ground can be determined in detail.
（発明の効果）
以上の説明から明らかなように、本発明は弾性波による
調査を゛行う地盤に弾性波発振源と地盤を伝播する弾性
波の速度を測定する２個の受振器とを１本のケーシング
パイプに収めて地盤に貫入し、弾性波発振源から発振さ
れる弾性波が地盤中を伝播するＳ波速度を２個の受振器
の波動到達時間差から求め、パイプを貫入して深度方向
に連続的にＳ波速度を求めるようにしているので、海底
地盤などのように発振源を地表面に設置できない場合や
ポーリング孔をあけ難い柔らかい地盤での弾性波探査を
可能とする。(Effects of the Invention) As is clear from the above description, the present invention provides a system in which an elastic wave oscillation source and two geophones for measuring the velocity of the elastic waves propagating through the ground are installed in the ground to be investigated using elastic waves. The S-wave velocity at which the elastic wave oscillated from the elastic wave oscillation source propagates through the ground is determined from the difference in wave arrival time between two geophones, and the S-wave velocity is determined by penetrating the pipe and penetrating into the ground. Since the S-wave velocity is continuously determined in the direction, it is possible to perform elastic wave exploration in cases where an oscillation source cannot be installed on the ground surface, such as undersea ground, or in soft ground where it is difficult to drill a polling hole.
また本発明によると、ケーシングパイプの貫入によって
弾性波発振源と受振器を地盤中にセットできるので、探
査に先立ってポーリング孔を穿孔しなくとも良く、調査
費用が安くできる。Further, according to the present invention, since the elastic wave oscillation source and the receiver can be set in the ground by penetrating the casing pipe, there is no need to drill a polling hole prior to exploration, and the survey cost can be reduced.
また本発明によると、単一ケーシングパイプ内の深度方
向に設置された２ｍの受振器の間の波動到達時間差から
弾性波の速度を求めるようにしているので、測定間隔が
一定している上に各受振器の出力信号の対照によってノ
イズを除去できるため測定精度が良い、更に、本発明に
よると、ケーシングパイプを貫入することによって深度
方向に連続してＳ波速度を計測できるので、詳細な地盤
の速度構造が得られる。Furthermore, according to the present invention, the velocity of elastic waves is determined from the difference in wave arrival times between 2m geophones installed in the depth direction within a single casing pipe, so the measurement interval is constant and The measurement accuracy is good because noise can be removed by comparing the output signals of each geophone.Furthermore, according to the present invention, the S-wave velocity can be measured continuously in the depth direction by penetrating the casing pipe, so detailed ground The velocity structure is obtained.
第１図は本発明の弾性波速度計測装置の原理図である。
第２図は同装置の詳細な構造の一例を示す縦断面図であ
る。
第３図は第２図の■方向矢視図である。
第４図は第２図のＴＶ−ＴＶ線断面図である。
１・・・ケーシングパイプ、
２・・・コーン、
３・・・弾性波発振源、
４．５・・・受振器、
７・・・正逆回転モータ、
８・・・加振部材、
１４．１５・・・打撃棒、
９・・・回転ハンマーFIG. 1 is a diagram showing the principle of the elastic wave velocity measuring device of the present invention. FIG. 2 is a longitudinal sectional view showing an example of the detailed structure of the device. FIG. 3 is a view taken in the direction of arrow (■) in FIG. 2. FIG. 4 is a sectional view taken along the line TV--TV in FIG. 2. DESCRIPTION OF SYMBOLS 1... Casing pipe, 2... Cone, 3... Elastic wave oscillation source, 4.5... Earth receiver, 7... Forward/reverse rotation motor, 8... Excitation member, 14. 15...Blowing rod, 9...Rotary hammer
Claims (4)
盤を伝播する弾性波の速度を測定する２個の受振器とを
１本のパイプに収めて地盤に貫入し、前記弾性波発振源
から発振される弾性波が地盤中を伝播するＳ波速度を前
記２個の受振器の波動到達時間差から求め、前記パイプ
を貫入して深度方向に連続的にＳ波速度を求めることを
特徴とする弾性波速度計測方法。(1) An elastic wave oscillation source and two geophones that measure the velocity of the elastic waves propagating through the ground are housed in one pipe, which penetrates the ground to be investigated using elastic waves, and the elastic wave oscillation source is inserted into the ground. The S-wave velocity at which an elastic wave oscillated from a source propagates through the ground is determined from the difference in wave arrival times between the two geophones, and the S-wave velocity is determined continuously in the depth direction by penetrating the pipe. A method for measuring elastic wave velocity.
プ内に収容されると共に一部がケーシングパイプの外に
突出した加振部材を有する弾性波発振源と、地盤中を伝
播する弾性波のＳ波速度を測定する受振器とから成り、
前記受振器は深度方向に一定間隔を開けて２個配置され
ていることを特徴とする弾性波速度計測装置。(2) A casing pipe that can penetrate into the ground; an elastic wave oscillation source that is housed within the pipe and has a vibrating member that partially protrudes outside the casing pipe; It consists of a geophone that measures the S-wave velocity,
An elastic wave velocity measuring device characterized in that two of the geophones are arranged at a constant interval in the depth direction.
中空体であることを特徴とする請求項２記載の弾性波探
査装置。(3) The elastic wave exploration device according to claim 2, wherein the casing pipe is a hollow body having a cone at its tip.
する請求項２又は３記載の弾性波探査装置。(4) The elastic wave exploration device according to claim 2 or 3, wherein the vibrating member is a gear-shaped ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14978990A JPH0756513B2 (en) | 1990-06-11 | 1990-06-11 | Method and apparatus for measuring elastic wave velocity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14978990A JPH0756513B2 (en) | 1990-06-11 | 1990-06-11 | Method and apparatus for measuring elastic wave velocity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0443989A true JPH0443989A (en) | 1992-02-13 |
| JPH0756513B2 JPH0756513B2 (en) | 1995-06-14 |
Family
ID=15482752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14978990A Expired - Fee Related JPH0756513B2 (en) | 1990-06-11 | 1990-06-11 | Method and apparatus for measuring elastic wave velocity |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756513B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000186319A (en) * | 1998-12-22 | 2000-07-04 | Ohbayashi Corp | Ground investigation method |
| CN107831218A (en) * | 2017-11-29 | 2018-03-23 | 四川陆通检测科技有限公司 | A kind of excitation apparatus and its method of testing for compressional wave |
| JP2018173354A (en) * | 2017-03-31 | 2018-11-08 | 国立研究開発法人産業技術総合研究所 | Rotary drive type hammering sound mechanism |
| CN112798474A (en) * | 2020-12-18 | 2021-05-14 | 西安科技大学 | Method and device for monitoring rock mass grouting diffusion range |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101120485B1 (en) * | 2009-07-07 | 2012-02-29 | 한국지질자원연구원 | Transverse wave generating apparatus for seismic survey |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58210585A (en) * | 1982-05-19 | 1983-12-07 | エクソン・プロダクシヨン・リサ−チ・コムパニ− | Measurement method by acoustic four pole shear wave and its device |
| JPS63315978A (en) * | 1987-06-19 | 1988-12-23 | Nippon Koei Kk | Ground survey instrument |
| JPH01265185A (en) * | 1988-04-18 | 1989-10-23 | Chuo Kaihatsu Kk | Measuring method for underground artificial elastic wave and its measuring sonde |
| JPH0255985A (en) * | 1988-08-19 | 1990-02-26 | Sankoo Consultant Kk | Method and device for measuring speed of shear wave and compressional wave of bed logging |
-
1990
- 1990-06-11 JP JP14978990A patent/JPH0756513B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58210585A (en) * | 1982-05-19 | 1983-12-07 | エクソン・プロダクシヨン・リサ−チ・コムパニ− | Measurement method by acoustic four pole shear wave and its device |
| JPS63315978A (en) * | 1987-06-19 | 1988-12-23 | Nippon Koei Kk | Ground survey instrument |
| JPH01265185A (en) * | 1988-04-18 | 1989-10-23 | Chuo Kaihatsu Kk | Measuring method for underground artificial elastic wave and its measuring sonde |
| JPH0255985A (en) * | 1988-08-19 | 1990-02-26 | Sankoo Consultant Kk | Method and device for measuring speed of shear wave and compressional wave of bed logging |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000186319A (en) * | 1998-12-22 | 2000-07-04 | Ohbayashi Corp | Ground investigation method |
| JP2018173354A (en) * | 2017-03-31 | 2018-11-08 | 国立研究開発法人産業技術総合研究所 | Rotary drive type hammering sound mechanism |
| CN107831218A (en) * | 2017-11-29 | 2018-03-23 | 四川陆通检测科技有限公司 | A kind of excitation apparatus and its method of testing for compressional wave |
| CN107831218B (en) * | 2017-11-29 | 2024-02-27 | 四川陆通检测科技有限公司 | Excitation device for longitudinal wave and test method thereof |
| CN112798474A (en) * | 2020-12-18 | 2021-05-14 | 西安科技大学 | Method and device for monitoring rock mass grouting diffusion range |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0756513B2 (en) | 1995-06-14 |
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