JPH0678957B2 - Bedrock pressure detector - Google Patents
Bedrock pressure detectorInfo
- Publication number
- JPH0678957B2 JPH0678957B2 JP61064207A JP6420786A JPH0678957B2 JP H0678957 B2 JPH0678957 B2 JP H0678957B2 JP 61064207 A JP61064207 A JP 61064207A JP 6420786 A JP6420786 A JP 6420786A JP H0678957 B2 JPH0678957 B2 JP H0678957B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure receiving
- pressure
- receiving plate
- plate pair
- plates
- 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
Description
【発明の詳細な説明】 （ａ）技術分野 本発明は、岩盤圧検出器に関し、より詳細には、少ない
埋設本数でもって多数の方向成分の岩盤圧検出をするこ
とができる岩盤圧検出器に関するものである。Description: (a) Technical Field The present invention relates to a bedrock pressure detector, and more particularly to a bedrock pressure detector capable of detecting a bedrock pressure of a large number of directional components with a small number of buried rocks. It is a thing.
（ｂ）従来技術 一般に、大規模な地下掘削を行なって地下に発電所やト
ンネルを建造する場合には、その岩盤内に作用している
掘削前の岩盤圧（初期応力・地山応力）状態を充分に把
握し得るデータを測定しておくと、設計の合理化や施工
時の保安に役立つ。また、このようなデータは、建造後
の地殻運動の予測にも役立たせることができる。(B) Conventional Technology Generally, when a large-scale underground excavation is performed to construct a power plant or tunnel underground, the bedrock pressure (initial stress / ground stress) acting on the bedrock before excavation. It is useful to rationalize the design and to secure the safety during the construction by measuring the data that can grasp the In addition, such data can be useful for predicting the crustal movement after construction.
さらに、建造後に、定期的にその周辺の岩盤圧（地圧）
を測定することによって、建造物破壊等の重大事故を未
然に防ぐことができる。Furthermore, after construction, the surrounding rock pressure (ground pressure) is regularly
By measuring, it is possible to prevent serious accidents such as building destruction.
ところで、岩盤圧の検出を行なうには種々の方法がある
が主として応力解放法と呼ばれるものが多く用いられて
いる。この応力解放法は、地圧から解放された時のその
岩盤部分のひずみまたは変形を測定して岩盤圧を推定し
ようとするものである。このような応力解放法の１つに
オーバーコアリング法がある。これは、岩盤に所定の深
さまで大口径のボーリングを行ない、続いてその奥部の
中央に小口径のパイロット孔を穿孔する。そして、穿孔
の際に得られた岩石コアの観察によって測定位置を決定
し、そのパイロット孔内に棒状の岩盤圧検出器を設置す
る。この場合の岩盤圧検出器は、棒状に形成された緩衝
部材と、この緩衝部材の長手軸に直交する面に、それぞ
れ受圧方向が45°異なるように上記長手軸を中心とする
等配角度位置に配設された第１乃至第４の受圧板対と、
上記第１乃至第４の受圧板対をなすそれぞれ２枚の受圧
板間に圧力伝達部材を介して介挿された第１乃至第４の
ひずみ計と、上記緩衝部材の長手軸方向に受圧方向を有
する長手軸方向ひずみ計、とを具備した構成となってい
る。従って、上述の第１乃至第４のひずみ計と長手軸方
向のひずみ計の各出力を適宜の手段で検出することによ
って５方向の成分の検出ができるようになっている。By the way, there are various methods for detecting the bedrock pressure, but a method called a stress release method is mainly used. This stress release method attempts to estimate the rock mass pressure by measuring the strain or deformation of the rock mass when it is released from the ground pressure. One of such stress releasing methods is an overcoring method. This involves boring a large diameter bore to a predetermined depth in the bedrock, followed by drilling a small diameter pilot hole in the center of the back. Then, the measurement position is determined by observing the rock core obtained at the time of drilling, and a rod-shaped rock mass pressure detector is installed in the pilot hole. In this case, the bedrock pressure detector is a rod-shaped cushioning member, and a surface orthogonal to the longitudinal axis of this cushioning member is arranged at equal angular positions about the longitudinal axis so that the pressure receiving directions differ by 45 °. First to fourth pressure receiving plate pairs arranged in
First to fourth strain gauges inserted between two pressure receiving plates forming the first to fourth pressure receiving plate pairs via pressure transmitting members, and a pressure receiving direction in the longitudinal axis direction of the buffer member. And a longitudinal axis strain gauge having. Therefore, the components in the five directions can be detected by detecting the outputs of the first to fourth strain gauges and the strain gauges in the longitudinal axis direction by appropriate means.
しかしながら、上記従来の岩盤圧検出器を用いて岩盤圧
の検出を多面的に行なうには、大口径のボーリングを行
ない、続いてその奥部の中央に小口径のパイロット孔を
穿孔する作業を、Ｘ座標軸とＹ座標軸とＺ座標軸とのそ
れぞれに対応して行ない、それぞれのパイロット孔に上
述の岩盤圧検出器を設置しなければならず、従って岩盤
圧の検出作業が非常に繁雑化し、ボーリング費用、その
他の設備費用が高額となるという問題がある。However, in order to perform multifaceted detection of rock mass pressure using the above-mentioned conventional rock mass pressure detector, a large-diameter boring is performed, and subsequently, a work of drilling a small-diameter pilot hole in the center of the back, It is necessary to perform the operation corresponding to each of the X-coordinate axis, the Y-coordinate axis, and the Z-coordinate axis, and install the above-mentioned rock mass pressure detector in each pilot hole. Therefore, the rock mass pressure detection work becomes very complicated, and the boring cost is high. However, there is a problem that other equipment costs will be high.
さらに、上記従来の岩盤圧検出器の場合、Ｘ座標軸とＹ
座標軸とＺ座標軸のそれぞれに設置される岩盤圧検出器
の位置を必然的に離れた場所に設置せざるを得ないの
で、岩盤の任意点における岩盤圧検出が不可能であると
いう難点があった。Furthermore, in the case of the conventional rock mass pressure detector, the X coordinate axis and Y
Since the position of the bedrock pressure detector installed on each of the coordinate axis and the Z coordinate axis is inevitably installed at a distant place, there is a drawback that it is impossible to detect the bedrock pressure at an arbitrary point on the bedrock. .
一方、このような問題を考慮して１本のボーリング孔に
設置するだけで、岩盤内の複数方向の応力を検出できる
ようにした地中応力測定装置が、特公昭48−12809号公
報に記載されている。On the other hand, in consideration of such problems, an underground stress measuring device capable of detecting stress in multiple directions in the bedrock simply by installing it in one boring hole is disclosed in Japanese Patent Publication No. 48-12809. Has been done.
上記公報記載の地中応力測定装置は、ボーリング孔への
挿入を容易にするため先端に円錐部を形成するととも
に、ボーリング孔への接着中その位置を保持するため
に、少なくとも一側周面上に複数の突出部を設けた円筒
に、互いに直角をなす３平面内に所定の方向を向いた電
気的ひずみ計を複数個設け、ボーリング孔により地中応
力状態の測定を行ない得るように構成されている。The underground stress measuring device described in the above publication forms a conical portion at the tip for facilitating insertion into the boring hole, and at least one side peripheral surface on the peripheral surface in order to hold the position during adhesion to the boring hole. A cylinder provided with a plurality of protrusions is provided with a plurality of electric strain gauges oriented in a predetermined direction in three planes which are perpendicular to each other, and the borehole can be used to measure the underground stress state. ing.
そして上記円筒は、これを合成樹脂その他の塑造可能の
材料により形成されるが、その弾性係数は、次の２要
件、即ち、 １）内部に電気的ひずみ計を設置したことにより影響を
受けないよう充分高いこと、 ２）岩盤の弾性係数より充分低いこと、 が必要であり、また、円筒をボーリング孔に接着するの
に、円筒の材料と同一の材料を使用することが条件とさ
れる。The cylinder is made of synthetic resin or other plastic material, but its elastic modulus is not affected by the following two requirements: 1) An electric strain gauge is installed inside. High enough, 2) well below the elastic modulus of the bedrock, and that the same material as that of the cylinder is used to bond the cylinder to the boring hole.
このような構成よりなる上記地中応力測定装置は、円筒
の直径よりも小直径のボーリング孔に円筒を無理に押し
込む方式であるため、円筒自体が変形するばかりでな
く、円筒内のひずみ計も変形を生じるため、予測しない
初期ひずみがひずみ計に加わり、所定の検出可能範囲の
限界を超えたり、破損するおそれがあり、また、検出可
能範囲内に収まったとしても分解能の低い領域での使用
（検出）を余儀なくされる、という難点がある。The above-mentioned underground stress measuring device having such a configuration is a method of forcing a cylinder into a boring hole having a diameter smaller than the diameter of the cylinder, so that not only the cylinder itself is deformed, but also a strain gauge inside the cylinder is used. Due to deformation, unpredictable initial strain is applied to the strain gauge, which may exceed the limit of the predetermined detectable range or damage, and even if it falls within the detectable range, it is used in the low resolution area. There is a drawback that (detection) is forced.
また、上記公報記載のものは、ひずみ計は、円筒内に配
設されているもののようであるが、その具体的な構成
は、不明であり、地中から受ける圧力の伝播径路も明ら
かではないが、公報の全体的な記載から判断して円筒の
周壁を介して地中よりの応力を受けるものと解される。
そうであるとすると、ひずみ計は、地中応力を岩盤から
接着剤樹脂層、塑造可能なる材料により形成された円筒
をそれぞれ介して受けることとなり、接着剤樹脂層や円
筒が応力伝達径路中においてクッション材の役割を果た
すこととなるため、ひずみ計への応力の伝達効率が低下
してしまう、という難点がある。Further, the strain gauge described in the above publication seems to be a strain gauge arranged in a cylinder, but its specific configuration is unknown, and the propagation path of pressure received from the ground is not clear. However, judging from the overall description of the publication, it is understood that the stress from the ground is received via the peripheral wall of the cylinder.
If so, the strain gauge receives the underground stress from the bedrock through the adhesive resin layer and the cylinder formed of the plasticizable material, respectively, and the adhesive resin layer and the cylinder in the stress transmission path. Since it plays the role of a cushion material, there is a drawback that the efficiency of transmitting stress to the strain gauge is reduced.
また、地中より応力を受ける円筒は、ひずみ計より大き
な弾性係数を有しており、一様な円筒体であるため、特
定の方向の地中応力を複数のひずみ計が唆別することが
できない、という難点もある。In addition, a cylinder that receives stress from the ground has a larger elastic modulus than a strain gauge and is a uniform cylinder, so multiple strain gauges may discriminate underground stress in a specific direction. There is also the drawback that it cannot be done.
（ｃ）目的 このような事情に鑑みて本発明がなされたので、その目
的とするとことは、 第１に、１本のボーリング孔に設置するだけで、岩盤の
狭い領域における任意点での多面的な岩盤圧を個別に検
出することができ、ボーリング費用や検出器、計測器等
の設置費用等からなるトータル費用を大幅に節減するこ
とのできる岩盤圧検出器を提供することにあり、 第２に、岩盤圧検出器を岩盤内に埋設するに当って、初
期ひずみを極めて僅かしか発生させず、検出可能範囲を
狭めることなく、分解能を犠牲にすることもなく、まし
て埋設時の損壊なども生じない岩盤圧検出器を提供する
ことにあり、 第３に、岩盤圧力を直接的に受け真の岩盤圧力に正確に
対応したひずみ出力を得ることができると共に、岩盤の
特定部分の特定方向の岩盤圧を他の部分や他方向からの
岩盤圧と峻別して検出し得る岩盤圧検出器を提供するこ
とにある。(C) Purpose Since the present invention has been made in view of such circumstances, the first purpose is to provide a multifaceted surface at an arbitrary point in a narrow area of rock mass by simply installing it in one boring hole. The purpose of the present invention is to provide a bedrock pressure detector that can detect individual bedrock pressures individually and can significantly reduce the total cost including boring cost, installation cost of detectors, measuring instruments, etc. 2. In embedding the bedrock pressure detector in the bedrock, it generates very little initial strain, does not narrow the detectable range, does not sacrifice the resolution, let alone damage at the time of embedding. The third reason is to provide a bedrock pressure detector that does not cause the above problem. Thirdly, it is possible to directly receive the bedrock pressure and obtain a strain output that accurately corresponds to the true bedrock pressure, and at the same time, in a specific direction of a specific part of the bedrock. Other bedrock pressure The object of the present invention is to provide a bedrock pressure detector that can detect the bedrock pressure by distinguishing it from the rock pressure from the other part or from other directions.
（ｄ）構成 上述の目的を達成するために、本発明に係る岩盤圧検出
器は、棒状に形成された弾性係数の小さな緩衝部材と、
この緩衝部材の長手軸方向に少しづつずれた位置におい
て該長手軸に直交する面に、それぞれの受圧方向が45°
異なるように上記長手軸を中心とする等配角度位置に上
記緩衝部材の外周面より突出するように配設されたそれ
ぞれ２枚の受圧板よりなる第１乃至第４の受圧板対と、
上記第１の受圧板対の受圧面と同一面に受圧面が形成さ
れると共にその受圧方向が上記第１の受圧板対の受圧方
向に対して45°異なって配設された２枚の受圧板よりな
る第５の受圧板対と、上記第２の受圧板対の受圧面と同
一面に受圧面が形成されると共にその受圧方向が上記第
２の受圧板対の受圧方向に対して45°異なって配設され
た２枚の受圧板よりなる第６の受圧板対と、上記第１の
受圧板対の受圧面と同一面に受圧面が形成されると共に
その受圧方向が上記第５の受圧板対の受圧方向に対して
直交して配設された２枚の受圧板よりなる第７の受圧板
対と、上記第２の受圧板対の受圧面と同一面に受圧面が
形成されると共にその受圧方向が上記第６の受圧板対の
受圧方向に対して直交して配設された２枚の受圧板より
なる第８の受圧板対と、上記第１乃至第８の受圧板対を
なすそれぞれ２枚の受圧板間に圧力伝達部材を介して介
挿されそれぞれの受圧板対に印加される被測定圧力に対
応する電気信号を出力する第１乃至第８のひずみ計と、
上記第１乃至第８の受圧板対をなす受圧板の間を列状に
仕切るように長手軸方向に沿わせ且つ上記緩衝部材の外
周面に立設させた状態で固定された複数の仕切り板と、
を具備してなり、岩盤に穿設されたボーリング孔に緩く
挿入され且つセメントミルクにより上記岩盤に上記第１
乃至第８の受圧板対が固着された状態下で上記岩盤内の
少なくとも８軸方向の岩盤圧を検出し得るように構成し
たことを特徴とするものである。(D) Configuration In order to achieve the above-mentioned object, a bedrock pressure detector according to the present invention includes a buffer member formed in a rod shape and having a small elastic coefficient,
Each of the pressure receiving directions is 45 ° on a plane orthogonal to the longitudinal axis at a position slightly displaced in the longitudinal axis direction of the cushioning member.
Differently, first to fourth pressure receiving plate pairs each formed of two pressure receiving plates arranged so as to project from the outer peripheral surface of the buffer member at equidistant angular positions about the longitudinal axis.
Two pressure receiving surfaces are formed in which a pressure receiving surface is formed on the same surface as the pressure receiving surface of the first pressure receiving plate pair, and the pressure receiving direction is different by 45 ° from the pressure receiving direction of the first pressure receiving plate pair. A fifth pressure receiving plate pair formed of a plate and a pressure receiving surface formed on the same surface as the pressure receiving surface of the second pressure receiving plate pair, and the pressure receiving direction thereof is 45 with respect to the pressure receiving direction of the second pressure receiving plate pair. ° A sixth pressure receiving plate pair composed of two pressure receiving plates arranged differently, and a pressure receiving surface is formed on the same surface as the pressure receiving surface of the first pressure receiving plate pair, and its pressure receiving direction is the fifth pressure receiving surface. No. 7 pressure receiving plate formed by two pressure receiving plates arranged orthogonal to the pressure receiving direction of the pair of pressure receiving plates, and a pressure receiving surface is formed on the same surface as the pressure receiving surface of the second pressure receiving plate pair. And a pressure receiving direction of the pressure receiving direction of the sixth pressure receiving plate pair which is orthogonal to the pressure receiving direction of the sixth pressure receiving plate pair. , And outputs an electric signal corresponding to the measured pressure applied to each of the pressure receiving plate pairs, which is interposed between the two pressure receiving plates forming the first to eighth pressure receiving plate pairs via a pressure transmitting member. First to eighth strain gauges,
A plurality of partition plates fixed along the longitudinal axis direction so as to partition the pressure-receiving plates forming the first to eighth pressure-receiving plate pairs in rows and standing on the outer peripheral surface of the buffer member.
And is loosely inserted into a boring hole drilled in the bedrock, and is cemented into the bedrock by the first
It is characterized in that it is configured so as to be able to detect the rock mass pressure in at least eight axial directions in the rock mass while the eighth pressure receiving plate pair is fixed.
以下、本発明の実施例を添付図面に基づいて詳細に説明
する。Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
第１図に示すように岩盤圧検出器100は、全体を略棒状
に形成され、その主体は、先端部100aとひずみ検出部10
0bと基部100cとで形成されている。そして、先端部100a
とひずみ検出部100bにかけて一体もしくは分割型の緩衝
部材２がゴムまたは弾性係数の小さい合成樹脂材料をも
って略円柱状に形成されている。このような緩衝部材２
の先端部には、４枚の案内板１が90°間隔で植設され、
上述のパイロット孔へ埋設する際のガイドとなってい
る。このような先端部100aには、ひずみ検出部100bが連
接されており、このひずみ検出部100bには、第１乃至第
８の受圧板対31乃至38が緩衝部材２の外周面より所定量
突出した状態で配設されている。即ち、第１の受圧板対
は、受圧板31a,31bよりなり、この受圧板31a,31bのそれ
ぞれの間には、圧力伝達部材としての圧力伝達ロッド41
を介して第１のひずみ計としてひずみ検出素子51が介挿
された状態で固定されている。そして、この第１の受圧
板対31の受圧方向は、第６図と第７図に示すように緩衝
部材２の長手軸Ｏに直交する面内に位置する符号P,Qを
結ぶ線上にある。As shown in FIG. 1, the bedrock pressure detector 100 is formed in a substantially rod shape as a whole, and its main components are the tip 100a and the strain detector 10.
It is formed by 0b and the base portion 100c. And the tip 100a
And the strain detecting portion 100b, the buffer member 2 which is integral or divided is formed in a substantially cylindrical shape with rubber or a synthetic resin material having a small elastic coefficient. Such a cushioning member 2
At the tip of the, four guide plates 1 are planted at 90 ° intervals,
It serves as a guide for embedding in the pilot hole described above. A strain detecting portion 100b is connected to the tip portion 100a, and the first to eighth pressure receiving plate pairs 31 to 38 project from the outer peripheral surface of the cushioning member 2 by a predetermined amount in the strain detecting portion 100b. It is arranged in a closed state. That is, the first pressure receiving plate pair is composed of pressure receiving plates 31a and 31b, and a pressure transmitting rod 41 as a pressure transmitting member is provided between the pressure receiving plates 31a and 31b.
A strain detecting element 51 is fixed as a first strain gauge via the. The pressure receiving direction of the first pressure receiving plate pair 31 is on the line connecting the symbols P and Q located in the plane orthogonal to the longitudinal axis O of the buffer member 2 as shown in FIGS. 6 and 7. .
また、第２の受圧板対32は、受圧板32a,32bよりなり、
この受圧板32a,32bのそれぞれの間には、圧力伝達ロッ
ド42を介して第２のひずみ計としてのひずみ検出素子52
が介挿された状態で固定されている。そして、この第２
の受圧板対32の受圧方向は、上述の長手軸Ｏに直交する
面内に位置する線P,Qを結ぶ線に対して直交した符号R,S
を結ぶ線上にある。また、第３の受圧板対33は、受圧板
33a,33bよりなり、この受圧板33a,33bのそれぞれの間に
は、圧力伝達ロッド43を介して第３のひずみ計としての
ひずみ検出素子53が固定されている。そして、この第３
の受圧板対33の受圧方向は、上述の長手軸Ｏに直交する
面内で、上記第２の受圧板対32の受圧方向に対し45°回
転した線上にある。さらに、第４の受圧板対34は、受圧
板34a,34bよりなり、この受圧板34a,34bのそれぞれの間
には、圧力伝達ロッド44を介して第４のひずみ計として
のひずみ検出素子54が介挿された状態で固定されてい
る。そして、この第４の受圧板対34の受圧方向は、上述
の長手軸Ｏに直交する面内で、上述の第３の受圧板対33
とは逆方向に45°回転した線上にある。The second pressure receiving plate pair 32 is composed of pressure receiving plates 32a and 32b,
A strain detecting element 52 as a second strain gauge is provided between the pressure receiving plates 32a and 32b via a pressure transmitting rod 42.
Is fixed in a state of being inserted. And this second
The pressure receiving direction of the pressure receiving plate pair 32 is R, S orthogonal to the line connecting the lines P, Q located in the plane orthogonal to the longitudinal axis O.
It is on the line connecting The third pressure receiving plate pair 33 is a pressure receiving plate.
33a and 33b, and a strain detecting element 53 as a third strain gauge is fixed between the pressure receiving plates 33a and 33b via a pressure transmission rod 43. And this third
The pressure receiving direction of the pressure receiving plate pair 33 is on a line rotated by 45 ° with respect to the pressure receiving direction of the second pressure receiving plate pair 32 in the plane orthogonal to the longitudinal axis O. Further, the fourth pressure receiving plate pair 34 is composed of pressure receiving plates 34a and 34b, and a strain detecting element 54 as a fourth strain gauge is interposed between the pressure receiving plates 34a and 34b via a pressure transmission rod 44. Is fixed in a state of being inserted. The pressure receiving direction of the fourth pressure receiving plate pair 34 is within the plane orthogonal to the longitudinal axis O described above, and the third pressure receiving plate pair 33 described above.
It is on the line rotated by 45 ° in the opposite direction.
従って、上述の第１乃至第４の受圧板対31〜34は、緩衝
部材２の長手軸Ｏ方向に少しづつずれた位置において該
長手軸Ｏに直交する面内に、それぞれの受圧方向が45°
異なるように上記長手軸Ｏを中心とする等配角度位置に
配設されているのである。Therefore, each of the first to fourth pressure receiving plate pairs 31 to 34 has a pressure receiving direction of 45 in the plane orthogonal to the longitudinal axis O at a position slightly displaced in the longitudinal axis O direction of the cushioning member 2. °
Differently, they are arranged at equal angular positions about the longitudinal axis O.
一方、第５の受圧板対35は、受圧板35a,35bよりなり、
この受圧板35a,35bのそれぞれの間には、圧力伝達ロッ
ド45を介して第５のひずみ計としてのひずみ検出素子55
か介挿された状態で固定されている。そして、この第５
の受圧板対35の受圧面は、上記第１の受圧板対31の受圧
面と同一面に形成されると共にその受圧方向が上記第１
の受圧板対31の受圧方向に対して長手軸を含む面内で45
°異なって配設されている。第６の受圧板対36は、受圧
板36a,36bよりなり、この受圧板36a,36bのそれぞれの間
には、圧力伝達ロッド46を介して第６のひずみ計として
のひずみ検出素子56が介挿された状態で固定されてい
る。そして、この第６の受圧板対36の受圧面は、上記第
２の受圧板対32の受圧面と同一面に形成されると共にそ
の受圧方向は上記第２の受圧板対32の受圧方向に対して
長手軸Ｏを含む面内で45°異ならせて配設されている。On the other hand, the fifth pressure receiving plate pair 35 includes pressure receiving plates 35a and 35b,
A strain detecting element 55 as a fifth strain gauge is provided between the pressure receiving plates 35a and 35b via a pressure transmitting rod 45.
It is fixed in the inserted state. And this fifth
The pressure receiving surface of the pressure receiving plate pair 35 is formed on the same surface as the pressure receiving surface of the first pressure receiving plate pair 31, and the pressure receiving direction thereof is the first pressure receiving surface.
45 in the plane including the longitudinal axis with respect to the pressure receiving direction of the pressure receiving plate pair 31 of
° Differently arranged. The sixth pressure receiving plate pair 36 is composed of pressure receiving plates 36a and 36b, and a strain detecting element 56 as a sixth strain gauge is interposed between the pressure receiving plates 36a and 36b via a pressure transmission rod 46. It is fixed in the inserted state. The pressure receiving surface of the sixth pressure receiving plate pair 36 is formed on the same surface as the pressure receiving surface of the second pressure receiving plate pair 32, and the pressure receiving direction thereof is in the pressure receiving direction of the second pressure receiving plate pair 32. On the other hand, they are arranged so as to be different by 45 ° in the plane including the longitudinal axis O.
また、第７の受圧板対37は、受圧板37a,37bよりなり、
この受圧板37a,37bのそれぞれの間には、圧力伝達ロッ
ド47を介して第７のひずみ計としてのひずみ検出素子57
が介挿された状態で固定されている。そして、この第７
の受圧板対37の受圧面は、上記第５の受圧板対35の受圧
面と同一面に形成されると共に、その受圧方向は上記第
５の受圧板対日５の受圧方向に対して長手軸Ｏを含む面
内で直交して配設されている。さらに、第８の受圧板対
38は、受圧板38a,38bよりなり、この受圧板38a,38bのそ
れぞれの間には、圧力伝達ロッド48を介して第８のひず
み計としてのひずみ検出素子58が介挿された状態で固定
されている。そして、この第８の受圧板対38の受圧面
は、上記第６の受圧板対36の受圧面と同一面に形成され
ると共にその受圧方向は、上記第６の受圧板対36の受圧
方向に対して長手軸Ｏを含む面内で直交するように配設
されている。The seventh pressure receiving plate pair 37 is composed of pressure receiving plates 37a and 37b,
A strain detecting element 57 as a seventh strain gauge is interposed between the pressure receiving plates 37a and 37b via a pressure transmitting rod 47.
Is fixed in a state of being inserted. And this 7th
The pressure receiving surface of the pressure receiving plate pair 37 is formed on the same surface as the pressure receiving surface of the fifth pressure receiving plate pair 35, and its pressure receiving direction is the longitudinal axis with respect to the pressure receiving direction of the fifth pressure receiving plate versus the date 5. They are arranged orthogonally in the plane containing O. Furthermore, the eighth pressure plate pair
38 is composed of pressure receiving plates 38a, 38b, and is fixed in a state in which a strain detecting element 58 as an eighth strain gauge is interposed between the pressure receiving plates 38a, 38b via a pressure transmission rod 48. Has been done. The pressure receiving surface of the eighth pressure receiving plate pair 38 is formed on the same surface as the pressure receiving surface of the sixth pressure receiving plate pair 36, and the pressure receiving direction is the pressure receiving direction of the sixth pressure receiving plate pair 36. Are arranged so as to be orthogonal to each other in a plane including the longitudinal axis O.
このように配設された第１乃至第８の受圧板対31乃至38
を構成する受圧板31a〜38a,31b〜38bは、第３図に示す
ように円周を８等分した角度位置に配設されており、そ
れぞれの受圧板間には、塩化ビニール材でなる帯状の板
を軸方向に沿わせて且つ緩衝部材２の外周面に立設させ
た状態で、塩化ビニール製の粘着テープにより緩衝部材
２の周面に固定された仕切り板５が８枚設けられてい
る。（第１図〜第３図）。この仕切板５を設けた理由
は、岩盤圧検出器100の埋設時にボーリング孔と計器の
間に充填されたセメントミルクが、硬化後に筒状になっ
て応力解放時に抵抗するので、硬化したセメントミルク
が筒状とならないようにするためである。The first to eighth pressure receiving plate pairs 31 to 38 arranged in this manner
The pressure receiving plates 31a to 38a and 31b to 38b constituting the are arranged at angular positions which divide the circumference into eight equal parts as shown in FIG. 3, and are made of vinyl chloride material between the respective pressure receiving plates. Eight partition plates 5 fixed to the peripheral surface of the cushioning member 2 with an adhesive tape made of vinyl chloride are provided in a state where the strip-shaped plate is arranged along the axial direction and is erected on the outer peripheral surface of the cushioning member 2. ing. (FIGS. 1 to 3). The reason why the partition plate 5 is provided is that the cement milk filled between the boring hole and the instrument when the bedrock pressure detector 100 is buried becomes a tubular shape after hardening and resists stress release, so the hardened cement milk is used. This is to prevent the shape from becoming cylindrical.
このように形成されたひずみ検出部100bの基端部には、
第１図に示すように、基部100cが連設されている。即
ち、緩衝部材２の左端部には、仕切り板５の端部が挿入
されるスリットが形成された支持金具６が嵌められ接着
剤により固定されている。そして緩衝部材２の左端縁に
は、絶縁材でなるパイプ７が挿入された状態で連結され
ている。このパイプ７内には、上述のひずみ検出素子51
〜58のそれぞれに接続されたリード線が挿通され、その
端末は２群に分割されて孔7a,7bから引き出されるよう
になっている。このようなパイプ７の間の周囲には、端
子板８が貼着されている。この端子板８は、第８図の展
開図と第９図の斜視図に示すように、いわゆるフレキシ
ブル基板で形成され、その表面には、合計18個の端子パ
ターン8aが形成され、この端子パターン8aのそれぞれに
は接続パターン8cを介して端子パターン8bが一体に形成
されている。このような端子板８は、第９図に示すよう
に筒状にされた状態で上述のパイプ７に接着剤により貼
着され、第１図に示す孔7aから導出されたリード線のそ
れぞれと上記端子パターン8aが半田接続される。また、
この端子板８と同様なものは、もう１つ有していて、上
述同様に孔7bから導出されたリード線のそれぞれと上記
端子パターン8aが半田接続される。そして、このときの
端子パターン8bが図示しないひずみ測定器に多芯ケーブ
ルを介して接続されるようになっている。At the base end of the strain detecting section 100b formed in this way,
As shown in FIG. 1, bases 100c are arranged in series. That is, a support metal fitting 6 having a slit into which the end portion of the partition plate 5 is inserted is fitted to the left end portion of the cushioning member 2 and fixed by an adhesive. A pipe 7 made of an insulating material is inserted and connected to the left end edge of the cushioning member 2. In this pipe 7, the above-mentioned strain detecting element 51
Lead wires connected to each of ~ 58 are inserted, and the ends thereof are divided into two groups and pulled out from the holes 7a, 7b. A terminal plate 8 is attached to the periphery of such pipes 7. As shown in the developed view of FIG. 8 and the perspective view of FIG. 9, this terminal board 8 is formed of a so-called flexible board, and a total of 18 terminal patterns 8a are formed on the surface thereof. A terminal pattern 8b is integrally formed on each of the 8a via a connection pattern 8c. Such a terminal board 8 is attached to the above-mentioned pipe 7 with an adhesive in a tubular shape as shown in FIG. 9, and is connected to each of the lead wires led out from the hole 7a shown in FIG. The terminal pattern 8a is soldered. Also,
Another terminal board 8 is also provided, and the lead wires led out from the holes 7b are soldered to the terminal patterns 8a as described above. The terminal pattern 8b at this time is connected to a strain measuring device (not shown) via a multi-core cable.
尚、上述のひずみ検出素子51〜58のそれぞれからは、４
本のリード線が引き出されており、その総本数が４×８
＝32（本）となっているので、上述の端子板８の端子パ
ターン8aは、１枚の端子板８に対して２個の予備端子が
あり、この予備端子には、図示しない調整抵抗等が接続
されるようになっている。In addition, from each of the strain detecting elements 51 to 58 described above, 4
4 lead wires are drawn out, and the total number is 4 x 8
= 32 (pieces), the terminal pattern 8a of the above-mentioned terminal board 8 has two spare terminals for one terminal board 8, and these spare terminals have adjustment resistors (not shown) or the like. Are connected.
そして、このようなパイプ７の周囲には、充填材９を介
してパッカー10が設けられている。A packer 10 is provided around the pipe 7 with a filler 9 interposed therebetween.
上述の先端部100aとひずみ検出部100bと基部100cで形成
される岩盤圧検出器100の長手方向に沿って断面が半円
状の位置決め溝３が形成されている。この位置決め溝３
を設けたのは、パイロット孔に岩盤圧検出器100を埋設
する際に、その設置方向を特定するためと、同岩盤圧検
出器100を固定する際のセメントミルクの充填を確実に
するためである。A positioning groove 3 having a semicircular cross section is formed along the longitudinal direction of the bedrock pressure detector 100 formed by the tip 100a, the strain detector 100b, and the base 100c. This positioning groove 3
The reason for providing is that when burying the bedrock pressure detector 100 in the pilot hole, to identify the installation direction and to ensure the filling of the cement milk when fixing the bedrock pressure detector 100. is there.
尚、ひずみ検出素子51〜58は、ひずみ計または微小変位
計等と称されるもので、印加される力に応じて起歪部ま
たはダイアフラムに生ずるひずみを、ひずみゲージによ
って電気抵抗の変化に変換するものである。The strain detecting elements 51 to 58 are called strain gauges or minute displacement gauges, and the strain generated in the strain-flexing portion or diaphragm according to the applied force is converted into a change in electrical resistance by a strain gauge. To do.
このような構成よりなる本実施例を用いて、オーバーコ
アリング法による岩盤圧の測定方法につき説明する。A method for measuring bedrock pressure by the overcoring method will be described with reference to the present embodiment having such a configuration.
先ず、岩盤に所定の深さまで大口径のボーリングを行な
い、続いてその奥部の中央に小口径のパイロット孔を穿
設する。そして、穿孔の際に得られた岩石コアの観察を
し、オーバーコアリングが可能であれば、そのままガイ
ドを用いて、同パイロット孔内に上述の岩盤圧検出器10
0をその先端部100aから挿入する。この際の岩盤圧検出
器100は、その位置決め溝３が適正なものとなるように
され、適宜の手段でもってセメントミルクが充填され
る。セメントミルクは、一般に７〜８日間硬化養生を行
う。このとき、受圧板31a〜38a,31b〜38bのそれぞれの
間には、仕切り板５が立設されているため、硬化したセ
メントミルクによって円筒体が形成されるようなことは
ない。従って、応力解放時にセメントミルクが抵抗とな
ることはない。First, large-diameter boring is performed on the rock to a predetermined depth, and then a small-diameter pilot hole is bored in the center of the deep part. Then, the rock core obtained at the time of drilling is observed, and if overcoring is possible, a guide is used as it is, and the above-mentioned rock mass pressure detector 10 is provided in the pilot hole.
Insert 0 from its tip 100a. At this time, the rock mass pressure detector 100 is configured so that the positioning groove 3 thereof is appropriate, and the cement milk is filled by an appropriate means. Cement milk is generally cured for 7 to 8 days. At this time, since the partition plate 5 is erected between the pressure receiving plates 31a to 38a and 31b to 38b, the hardened cement milk does not form a cylindrical body. Therefore, the cement milk does not resist the stress release.
硬化養生が終了したら、計器のゼロ点をとって、オーバ
ーコアリングを開始する。オーバーコアリングの掘進が
所定量進む毎にひずみ変化を測定していく。オーバーコ
アリングが終了したら、岩盤圧検出器の埋設されたコア
を回収し、大型の室内三軸試験装置にかけて等圧試験を
行なう。即ち、８成分の第１〜第８のひずみ計が、オー
バーコアリング時に変化したひずみ量（解放ひずみ）を
すべて押し戻すまで、圧力をかけ、その圧力値を測定す
る。この圧力値は、岩盤圧に対応する。After curing and curing, take the zero point of the instrument and start overcoring. The strain change is measured every time the overcoring progresses by a predetermined amount. After over-coring is completed, the embedded core of the bedrock pressure detector is recovered and subjected to a large-scale indoor triaxial tester to perform an isobaric test. That is, pressure is applied and the pressure value is measured until the eight component first to eighth strain gauges push back all the strain amounts (release strains) changed during overcoring. This pressure value corresponds to the bedrock pressure.
次に、このような岩盤圧検出器自体の作用につき説明す
る。第１乃至第８のひずみ計であるひずみ検出素子51〜
58をそれぞれから得られる電気信号、例えば、第１の受
圧板対31に生じる応力によって得られるひずみ検出素子
51の出力は、第６図に示すように符号51Pで示す方向か
ら印加される圧力の大きに対応し、第２の受圧板対32に
よるひずみ検出素子52の出力は、符号52Pで示す方向、
即ち上記符号51Pで示す方向に直交する方向から印加さ
れる圧力の大きさに対応する。Next, the operation of the bedrock pressure detector itself will be described. Strain detecting element 51, which is the first to eighth strain gauges
58 is an electric signal obtained from each of them, for example, a strain detecting element obtained by the stress generated in the first pressure receiving plate pair 31.
The output of 51 corresponds to the magnitude of the pressure applied from the direction indicated by the reference numeral 51P as shown in FIG. 6, and the output of the strain detecting element 52 by the second pressure receiving plate pair 32 is the direction indicated by the reference numeral 52P.
That is, it corresponds to the magnitude of the pressure applied in the direction orthogonal to the direction indicated by the reference numeral 51P.
以下同様に、ひずみ検出素子53の出力は、符号53Pで示
すように上記符号51Pで示す方向に対して45°回転した
方向から印加される圧力の大きさに対応する。また、第
４乃至第８の受圧板対34〜38によるひずみ検出素子54〜
58の出力は、それぞれ符号54P,55P,56P,57P,58Pで示す
方向から印加される圧力の大きさに対応する。Similarly, the output of the strain detecting element 53 corresponds to the magnitude of the pressure applied from the direction rotated by 45 ° with respect to the direction indicated by the reference numeral 51P, as indicated by the reference numeral 53P. In addition, the strain detecting elements 54 to 34 by the fourth to eighth pressure receiving plate pairs 34 to 38
The output of 58 corresponds to the magnitude of the pressure applied from the directions indicated by reference numerals 54P, 55P, 56P, 57P and 58P, respectively.
よって１本の岩盤圧検出器100を用いるのみで、第７図
に示すようにボーリングの孔軸方向に直交する面内の、
Ａ−Ａ′とＢ−Ｂ′と、Ｃ−Ｃ′とＤ−Ｄ′方向の４成
分がひずみ検出素子51〜54で検出でき、Ａ−Ａ′とＢ−
Ｂ′と、Ｃ−Ｃ′とＤ−Ｄ′方向の上述の４成分に対し
てそれぞれ45°異なる方向の成分がひずみ検出素子55〜
58で検出できるのである。Therefore, by using only one bed pressure detector 100, as shown in FIG. 7, in the plane orthogonal to the bore axis direction of the boring,
Four components in the directions A-A 'and BB', CC 'and DD' can be detected by the strain detecting elements 51 to 54, and A-A 'and B-
B ', C-C' and D-D 'directions have components different from each other by 45 ° with respect to the above-mentioned four components.
It can be detected at 58.
（ｅ）効果 このように本発明によれば、次のような顕著な効果を奏
し得る岩盤圧検出器を提供することができる。(E) Effects As described above, according to the present invention, it is possible to provide a bedrock pressure detector capable of producing the following remarkable effects.
第１に、１本の緩衝部材の長手軸方向に少しづつずれた
位置においてそれぞれの受圧方向が異なるように配設さ
れたそれぞれ２枚の受圧板よりなる第１乃至第８の受圧
板対で、１つのボーリング孔内の小領域での異なる８方
向の成分の岩盤圧を検出することができ、従って、ボー
リングの穿孔数が１つで足り、費用の嵩むボーリング穿
孔の手数が少なくできると共に、岩盤圧検出器の設置が
一度で済むので、大幅な経費節減が達成できる。First, there are first to eighth pressure receiving plate pairs each including two pressure receiving plates that are arranged so that the pressure receiving directions of the shock absorbing members are slightly different from each other in the longitudinal axis direction. It is possible to detect the rock pressures of the components in eight different directions in a small area in one boring hole. Therefore, one boring hole is sufficient, and the number of costly boring holes can be reduced. Since the bedrock pressure detector needs to be installed only once, significant cost savings can be achieved.
第２に、第１乃至第８の受圧板対は、棒状に形成された
弾性係数の小さな緩衝部材の外表面より突出するように
配設されており、岩盤中に埋設されるに際して、ボーリ
ング孔に緩く挿入され且つセメントミルクによって各受
圧板がボーリング孔の内壁に固着されるため、各受圧板
は岩盤と実質的に同程度の剛性を持つ硬化後のセメント
ミルクによって岩盤に一体的に強固に連接されることに
なり、 しかも各受圧板以外の圧力伝達部材および第１乃至第８
のひずみ計は、緩衝部材によってその周囲を囲繞されて
いるから、セメントミルクと隔絶され、岩盤圧は各受圧
板のみに作用し、その受圧板から圧力伝達部材を介して
各ひずみ計に伝達されるから、各ひずみ計は、各受圧板
と一体化された岩盤部分の岩盤圧のみを受けて忠実に電
気量（ひずみ出力信号）に変換することができる。Secondly, the first to eighth pressure receiving plate pairs are arranged so as to project from the outer surface of the shock absorbing member formed in the shape of a rod and having a small elastic coefficient. Since each pressure plate is loosely inserted into the borehole and cement milk fixes each pressure plate to the inner wall of the boring hole, each pressure plate is solidified to the rock mass by the cement milk after hardening which has substantially the same rigidity as the rock mass. The pressure transmitting members other than the pressure receiving plates and the first to eighth parts are connected to each other.
Since the strain gauges are surrounded by a buffer member, they are isolated from the cement milk, and the bedrock pressure acts only on each pressure receiving plate, and is transmitted from each pressure receiving plate to each strain gauge through the pressure transmitting member. Therefore, each strain gauge can receive only the bedrock pressure of the bedrock portion integrated with each pressure receiving plate and faithfully convert it into an electric quantity (strain output signal).
第３に、第１〜第８の受圧板対をなす各受圧板の間を列
状に仕切るように長手方向に沿わせ且つ上記緩衝部材の
外周面に立設させた状態で仕切り板を固定させた構成と
したから、岩盤圧検出器の埋設時にボーリング孔と岩盤
圧検出器の間に充填されたセメントミルクが、硬化後に
筒状になって応力解放時に抵抗することがなく、また、
方向の異なる岩盤圧の影響（干渉）を少なくし、各受圧
板毎の受圧板を唆別して検出することができる。Thirdly, the partition plates are fixed in a state in which the pressure-receiving plates forming the first to eighth pressure-receiving plate pairs are arranged along the longitudinal direction so as to partition the pressure-receiving plates in a row and are erected on the outer peripheral surface of the buffer member. Because of the configuration, the cement milk filled between the boring hole and the bedrock pressure detector when burying the bedrock pressure detector does not become cylindrical after hardening and resists stress release.
The influence (interference) of bedrock pressure in different directions can be reduced, and the pressure receiving plates can be detected separately for each pressure receiving plate.
また、第４に、各受圧板は上述の如く硬化後のコンクリ
ートミルクによってボーリング孔内の内壁と一体的に接
合されるため、埋設時点の岩盤圧に対し、岩盤圧が増加
したときはもちろんのこと、岩盤圧が減少したときも、
その岩盤圧の変化に正確に追従するひずみ出力を得るこ
とができる。Fourth, since each pressure receiving plate is integrally joined to the inner wall in the boring hole by the hardened concrete milk as described above, when the bedrock pressure increases with respect to the bedrock pressure at the time of burial. In fact, when the bedrock pressure decreases,
It is possible to obtain a strain output that accurately follows changes in the bedrock pressure.
第１図は、本発明の一実施例を示す岩盤圧検出器の正面
図、第２図は、上記第１図のII−II線切断断面図、第３
図は、上記第１図のIII−III線切断断面図、第４図は、
本発明の要部構成を示す正面図、第５図は、上記第１図
の受圧板の配置関係を示す斜視図、第６図は、第１図に
示される実施例中のひずみ検出素子の検出方向を模式的
に示す斜視図、第７図は、各ひずみ検出素子の検出方向
を模式的に示す側面図、第８図は、同実施例中の端子板
の展開図、第９図は、同端子板の斜視図である。 １……案内板、２……緩衝部材、 ５……仕切り板、６……支持金具、 ７……パイプ、８……端子板、 ９……充填材、10……パッカー、 31〜38……第１〜第８の受圧板対、 31a〜38a,31b〜38b……受圧板、 41〜48……圧力伝達ロッド、 51〜58……ひずみ検出素子（第１〜第８のひずみ計）。FIG. 1 is a front view of a bedrock pressure detector showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG.
FIG. 4 is a sectional view taken along the line III-III of FIG. 1, and FIG.
FIG. 5 is a front view showing the configuration of the main part of the present invention, FIG. 5 is a perspective view showing the positional relationship of the pressure receiving plate of FIG. 1, and FIG. 6 is a strain detecting element in the embodiment shown in FIG. FIG. 7 is a perspective view schematically showing the detection direction, FIG. 7 is a side view schematically showing the detection direction of each strain detection element, FIG. 8 is a developed view of the terminal board in the same embodiment, and FIG. FIG. 3 is a perspective view of the terminal board. 1 ... Guide plate, 2 ... Buffer member, 5 ... Partition plate, 6 ... Supporting metal, 7 ... Pipe, 8 ... Terminal plate, 9 ... Filling material, 10 ... Packer, 31-38 ... ... 1st to 8th pressure receiving plate pair, 31a to 38a, 31b to 38b ... Pressure receiving plate, 41 to 48 ... Pressure transmission rod, 51 to 58 ... Strain detecting element (1st to 8th strain gauge) .
フロントページの続き (56)参考文献 特公 昭48−12809（ＪＰ，Ｂ１)Continuation of front page (56) References Japanese Patent Publication Sho 48-12809 (JP, B1)
Claims (1)
材と、この緩衝部材の長手軸方向に少しづつずれた位置
において該長手軸に直交する面に、それぞれの受圧方向
が45°異なるように上記長手軸を中心とする等配角度位
置に上記緩衝部材の外周面より突出するように配設され
たそれぞれ２枚の受圧板よりなる第１乃至第４の受圧板
対と、上記第１の受圧板対の受圧面と同一面に受圧面が
形成されると共にその受圧方向が上記第１の受圧板対の
受圧方向に対して45°異なって配設された２枚の受圧板
よりなる第５の受圧板対と、上記第２の受圧板対の受圧
面と同一面に受圧面が形成されると共にその受圧方向が
上記第２の受圧板対の受圧方向に対して45°異なって配
設された２枚の受圧板よりなる第６の受圧板対と、上記
第１の受圧板対の受圧面と同一面に受圧面が形成される
と共にその受圧方向が上記第５の受圧板対の受圧方向に
対して直交して配設された２枚の受圧板よりなる第７の
受圧板対と、上記第２の受圧板対の受圧面と同一面に受
圧面が形成されると共にその受圧方向が上記第６の受圧
板対の受圧方向に対して直交して配設された２枚の受圧
板よりなる第８の受圧板対と、上記第１乃至第８の受圧
板対をなすそれぞれ２枚の受圧板間に圧力伝達部材を介
して介挿されそれぞれの受圧板対に印加される被測定圧
力に対応する電気信号を出力する第１乃至第８のひずみ
計と、上記第１乃至第８の受圧板対をなす受圧板の間を
列状に仕切るように長手軸方向に沿わせ且つ上記緩衝部
材の外周面に立設させた状態で固定された複数の仕切り
板と、を具備してなり、岩盤に穿設されたボーリング孔
に緩く挿入され且つセメントミルクにより上記岩盤に上
記第１乃至第８の受圧板対が固着された状態下で上記岩
盤内の少なくとも８軸方向の岩盤圧を検出し得るように
構成したことを特徴とする岩盤圧検出器。1. A pressure-absorbing member formed in a rod shape and having a small elastic coefficient, and a pressure-receiving direction differing from each other by 45 ° on a surface orthogonal to the longitudinal axis at a position slightly shifted in the longitudinal axis direction of the cushioning member. First to fourth pressure receiving plate pairs, each of which is formed of two pressure receiving plates and are arranged so as to project from the outer peripheral surface of the buffer member at equidistant angular positions about the longitudinal axis. A pressure receiving surface is formed on the same surface as the pressure receiving surface of the pair of pressure receiving plates, and the pressure receiving direction is composed of two pressure receiving plates arranged different by 45 ° from the pressure receiving direction of the first pressure receiving plate pair. A pressure receiving surface is formed on the same surface as the pressure receiving surface of the fifth pressure receiving plate pair and the pressure receiving surface of the second pressure receiving plate pair, and the pressure receiving direction differs from the pressure receiving direction of the second pressure receiving plate pair by 45 °. Pressure reception of a sixth pressure receiving plate pair composed of two pressure receiving plates arranged and the first pressure receiving plate pair A pressure receiving surface formed on the same surface as the pressure receiving surface, and a pressure receiving direction of the pressure receiving direction is orthogonal to the pressure receiving direction of the fifth pressure receiving plate pair; Two pressure receiving plates, each of which has a pressure receiving surface formed on the same surface as the pressure receiving surface of the second pressure receiving plate pair and whose pressure receiving direction is orthogonal to the pressure receiving direction of the sixth pressure receiving plate pair. To be measured, which is inserted between each of the eighth pressure receiving plate pair and the two pressure receiving plates forming the first to eighth pressure receiving plate pairs via a pressure transmitting member and is applied to each pressure receiving plate pair. The first to eighth strain gauges that output an electric signal corresponding to the pressure and the pressure receiving plates that form the first to eighth pressure receiving plate pairs are arranged along the longitudinal axis so as to partition the space between the first and eighth pressure receiving plates, and the buffer member. And a plurality of partition plates fixed in a state of being erected on the outer peripheral surface of the It is configured to be able to detect rock pressure in at least eight axial directions in the rock under the condition that it is loosely inserted in the boring hole and the first to eighth pressure receiving plate pairs are fixed to the rock by cement milk. A bedrock pressure detector characterized by.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61064207A JPH0678957B2 (en) | 1986-03-24 | 1986-03-24 | Bedrock pressure detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61064207A JPH0678957B2 (en) | 1986-03-24 | 1986-03-24 | Bedrock pressure detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62220823A JPS62220823A (en) | 1987-09-29 |
| JPH0678957B2 true JPH0678957B2 (en) | 1994-10-05 |
Family
ID=13251399
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61064207A Expired - Lifetime JPH0678957B2 (en) | 1986-03-24 | 1986-03-24 | Bedrock pressure detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0678957B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112378786A (en) * | 2020-10-27 | 2021-02-19 | 连云港市建设工程质量检测中心有限公司 | Method for measuring compressive strength of rock on site |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0325339A (en) * | 1989-06-13 | 1991-02-04 | Eti Explosives Technol Internatl | Sensor unit for monitoring stress in material, monitor and monitoring method |
| US9027411B2 (en) | 2012-04-03 | 2015-05-12 | Public Interest Incorporated Foundations Association For The Development Of Earthquake Prediction | Stress and strain sensing device |
| JP6245471B2 (en) * | 2013-12-04 | 2017-12-13 | 国立大学法人横浜国立大学 | Strain tensor calculation system, strain gauge sticking direction determination method, strain tensor calculation method, and strain tensor calculation program |
-
1986
- 1986-03-24 JP JP61064207A patent/JPH0678957B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112378786A (en) * | 2020-10-27 | 2021-02-19 | 连云港市建设工程质量检测中心有限公司 | Method for measuring compressive strength of rock on site |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62220823A (en) | 1987-09-29 |
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