JPH0593416A - Device for providing shearing wave for ground and measuring method of liquefaction strength - Google Patents
Device for providing shearing wave for ground and measuring method of liquefaction strengthInfo
- Publication number
- JPH0593416A JPH0593416A JP16511891A JP16511891A JPH0593416A JP H0593416 A JPH0593416 A JP H0593416A JP 16511891 A JP16511891 A JP 16511891A JP 16511891 A JP16511891 A JP 16511891A JP H0593416 A JPH0593416 A JP H0593416A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- shear wave
- weight
- shearing
- water pressure
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 26
- 238000010008 shearing Methods 0.000 title abstract 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000011148 porous material Substances 0.000 claims description 25
- 230000001902 propagating effect Effects 0.000 claims description 3
- 230000000644 propagated effect Effects 0.000 abstract description 2
- 238000004873 anchoring Methods 0.000 abstract 3
- 239000000523 sample Substances 0.000 description 8
- 238000010998 test method Methods 0.000 description 7
- 230000001133 acceleration Effects 0.000 description 6
- 230000035515 penetration Effects 0.000 description 5
- 238000012360 testing method Methods 0.000 description 4
- 238000009530 blood pressure measurement Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005422 blasting Methods 0.000 description 2
- 238000005056 compaction Methods 0.000 description 2
- 230000001186 cumulative effect Effects 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、剪断波を地盤に与える
装置に関し、さらに詳しくは、地盤に開けたボーリング
孔内で剪断波を繰り返し発生させ、この剪断波を地盤に
伝播させて、地盤に液状化状態を発生させることができ
る装置に関する。さらに本発明は、この装置を用いて剪
断波を与えた地盤の間隙水圧を測定することにより地盤
の液状化強度を現位置で測定することができる方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for applying a shear wave to the ground. More specifically, the shear wave is repeatedly generated in a boring hole formed in the ground, and the shear wave is propagated to the ground. The present invention relates to a device capable of generating a liquefied state. Further, the present invention relates to a method capable of measuring the liquefaction strength of the ground at the present position by measuring the pore water pressure of the ground to which a shear wave is applied using this device.
【０００２】[0002]
【従来の技術】地盤の液状化の強度を予想し、これに基
ずいて、耐震性に優れた構造物を建設することは、地震
の多い我が国においては、極めて重要なことである。2. Description of the Related Art Predicting the strength of ground liquefaction and constructing a structure having excellent earthquake resistance based on this is extremely important in Japan where there are many earthquakes.
【０００３】従来の地盤の液状化の強度の評価法には、
大きく別けて２種類あり、現位置試験法と室内試験法が
ある。現位置試験法には、標準貫入試験法、杭の振動
（サンドコンパクションパイル）を利用する方法、発破
による方法及びピエゾメータープローブを用いる方法等
がある。The conventional methods for evaluating the strength of liquefaction of the ground are:
There are roughly two types, the current position test method and the indoor test method. The in-situ test method includes a standard penetration test method, a method using vibration of a pile (sand compaction pile), a method by blasting and a method using a piezometer probe.
【０００４】具体的には、標準貫入試験法は、実際の地
震で液状化した地点及び液状化しなかった地点におい
て、標準貫入試験により求めたＮ値を比較するか、また
は室内試験で得られる液状化強度とＮ値を対応させるこ
とにより、液状化予想を行う方法である。杭の振動を利
用する方法は、サンドコンパクションパイルの施工時や
杭の振動打込時に、その周辺の地盤に生じる加速度と間
隙水圧とを測定し、その結果から、液状化のし易さを求
める方法である。発破による方法は、地中で火薬を爆破
させ、発破点から一定距離の円周上における地盤の平均
沈下量および過剰間隙水圧を測定し、その結果から液状
化のし易さを求める方法である。ピエゾメータープロー
ブを用いる方法は、ピエゾメータープローブによって求
められる貫入抵抗と静的な過剰間隙水圧の関係から、液
状化のし易さを求める方法である。[0004] Specifically, the standard penetration test method is to compare the N values obtained by the standard penetration test at a liquefied point and an unliquefied point in an actual earthquake or to obtain a liquid obtained by an indoor test. This is a method of predicting liquefaction by associating the liquefaction strength with the N value. The method of utilizing the vibration of the pile is to measure the acceleration and pore water pressure that occur in the ground around it when constructing a sand compaction pile or when driving the pile into vibration, and determine the ease of liquefaction from the results. Is the way. The blast method is a method of exploding explosives in the ground, measuring the average subsidence amount and excess pore water pressure of the ground on the circumference of a certain distance from the blast point, and determining the ease of liquefaction from the results. .. The method using a piezometer probe is a method for determining the ease of liquefaction based on the relationship between the penetration resistance and the static excess pore water pressure required by the piezometer probe.
【０００５】[0005]
【発明が解決しようとする課題】標準貫入試験法及びピ
エゾメータープローブを用いる方法は、比較的容易に行
うことができる。しかし、これらの方法は、直接、地盤
の液状化強度を測定するものではなく、これら試験法か
ら得られた結果から、経験により間接的に液状化強度を
求めるものであって、信頼性に疑問もある。その点、杭
の振動を利用する方法及び発破による方法は、直接液状
化強度を求めることができる。しかし、これらの方法
は、実験の規模が大きくなり、実施に際しては多大のコ
ストがかかるという問題がある。The standard penetration test method and the method using a piezometer probe are relatively easy to carry out. However, these methods do not directly measure the liquefaction strength of the ground, but indirectly obtain the liquefaction strength by experience from the results obtained from these test methods, and doubt the reliability. There is also. In this respect, the liquefaction strength can be directly obtained by the method using vibration of the pile and the method by blasting. However, these methods have a problem that the scale of the experiment becomes large and that the cost is large when the method is performed.
【０００６】一方、室内試験法は、現場から地盤の不攪
乱試料を採取し、この試料に対してて試験室において繰
り返し三軸試験を行うものである。従って、不攪乱試料
さえ入手できれば、より正確な液状化強度の算出が可能
である。しかし、実際には不攪乱試料を採取することが
必ずしも容易ではなく、また、攪乱された試料では実際
の液状化強度を求めることはできない。On the other hand, in the laboratory test method, an undisturbed sample of the ground is sampled from the site, and this sample is repeatedly subjected to a triaxial test in a test room. Therefore, more accurate calculation of liquefaction strength is possible if only undisturbed samples are available. However, actually, it is not always easy to collect an undisturbed sample, and the actual liquefaction strength cannot be obtained from the disturbed sample.
【０００７】そこで、本発明の目的は、現位置で比較的
容易にかつより正確に液状化強度を測定するために必要
な、地盤に剪断波を与えることができる簡易型の装置を
提供することにある。[0007] Therefore, an object of the present invention is to provide a simple type device capable of giving a shear wave to the ground, which is necessary for measuring the liquefaction strength relatively easily and more accurately at the present position. It is in.
【０００８】さらに、本発明の目的は、上記装置を用い
て、現位置で比較的容易にかつより正確に液状化強度を
測定できる方法を提供することにある。Further, it is an object of the present invention to provide a method capable of relatively easily and more accurately measuring the liquefaction strength at the present position by using the above apparatus.
【０００９】[0009]
【課題を解決するための手段】本発明は、剪断波発生部
及び該剪断波発生部を地盤に開けた孔内に固定し、かつ
該剪断波発生部で発生させた剪断波を地盤に伝える固定
手段からなる、剪断波を地盤に与える装置（以下、剪断
波発生装置という）であって、前記剪断波発生部は、往
復動し、ストッパーに衝突することにより剪断波を発生
させる錘、該錘を往復動させる駆動手段、並びに前記錘
及び駆動手段を収納し、内部に前記ストッパーを設け、
かつ前記錘の往復動により発生した剪断波を地盤孔の内
壁に伝えるための容器とからなり、前記固定手段は、対
向する一対の支持板及び該支持板の間を架橋し、かつ該
支持板の間隔を変動させることが可能な少なくとも２つ
の支柱手段とからなり、前記支持板のいずれか一方に前
記剪断波発生部の容器が固定されていることを特徴とす
る前記装置に関する。According to the present invention, a shear wave generator and a shear wave generator are fixed in a hole opened in the ground, and the shear wave generated in the shear wave generator is transmitted to the ground. An apparatus for applying a shear wave to the ground (hereinafter referred to as a shear wave generating apparatus), which comprises a fixing means, wherein the shear wave generating section reciprocates, and a weight that generates a shear wave by colliding with a stopper, A drive means for reciprocating the weight, and the weight and the drive means are housed, and the stopper is provided inside.
And a container for transmitting a shear wave generated by the reciprocating motion of the weight to the inner wall of the ground hole, the fixing means bridges between a pair of opposing support plates and the space between the support plates. The present invention relates to the above-mentioned device, characterized in that it comprises at least two support means capable of varying the above, and the container of the shear wave generating section is fixed to one of the support plates.
【００１０】さらに本発明は、地盤に開けた孔内に設置
した上記剪断波発生装置から地盤に剪断波を繰り返し与
え、地盤内を伝播した剪断波により変化する間隙水圧
を、前記孔と同一の孔内に上記装置から一定距離に設置
した間隙水圧計により測定することを特徴とする地盤の
液状化強度の測定方法に関する。Further, according to the present invention, a shear wave is repeatedly applied to the ground from the shear wave generator installed in the hole opened in the ground, and the pore water pressure changing by the shear wave propagating in the ground is the same as that of the hole. The present invention relates to a method for measuring the liquefaction strength of the ground, which is measured by a pore water pressure gauge installed in the hole at a constant distance from the device.
【００１１】以下本発明について詳細に説明する。The present invention will be described in detail below.
【００１２】本発明の１態様である剪断波発生装置１
は、図１に示すように、剪断波発生部２及び該剪断波発
生部２を地盤に開けた孔内に固定し、かつ該剪断波発生
部２で発生させた剪断波を地盤に伝える固定手段３から
なる。尚、図中４は剪断波発生部２の電源であり、５は
固定手段３を稼働させるための源である。Shear wave generator 1 according to one embodiment of the present invention
As shown in FIG. 1, the shear wave generator 2 and the shear wave generator 2 are fixed in a hole opened in the ground, and the shear wave generated in the shear wave generator 2 is fixed to the ground. It consists of means 3. In the figure, 4 is a power source for the shear wave generator 2, and 5 is a source for operating the fixing means 3.
【００１３】剪断波発生部１は、図１のＡ−Ａ’拡大部
分断面図である図２に示すように、内部が中空の容器１
１からなり、該容器１１の内部は、２つのストッパー１
２及び１３で３分割されている。錘１４は、上下面に上
下方向に延在させた２本の軸１５を有する。ストッパー
１２及び１３の中心部には、この軸１５が貫通できる大
きさの孔１６がある。ストッパー１２及び１３の間の部
屋の長さは、錘１４が上下動できるように、錘１４の長
さより大きく、錘１４は、ストッパー１２及び１３の孔
１６を軸１５が貫通するように、ストッパー１２及び１
３の間の部屋にセットさる。As shown in FIG. 2, which is an enlarged partial sectional view taken along the line AA 'of FIG. 1, the shear wave generating section 1 has a hollow interior 1
The inside of the container 11 consists of two stoppers 1.
It is divided into 3 by 2 and 13. The weight 14 has two shafts 15 extending in the vertical direction on the upper and lower surfaces. At the center of the stoppers 12 and 13, there is a hole 16 large enough for the shaft 15 to pass through. The length of the chamber between the stoppers 12 and 13 is larger than the length of the weight 14 so that the weight 14 can move up and down, and the weight 14 has a stopper so that the shaft 15 penetrates the holes 16 of the stoppers 12 and 13. 12 and 1
Set in the room between 3.
【００１４】容器１１のストッパー１２及び１３で仕切
られた端の部屋の少なくとも一方に、錘１４を往復動さ
せる駆動手段として電磁石１７を収納する。これは、電
磁プランジャーの原理を利用して、電磁石１７で、錘１
４の上下面に上下方向に延在させた軸１５に磁力を加え
ることで、錘１４を往復動させる。上下に往復動する錘
１４を、ストッパー１２及び１３に衝突させることによ
り剪断波を発生させる。容器１１は、錘１４が往復動し
てストッパー１２及び１３に衝突するとこにより発生し
た剪断波を後述の支持板３０に伝える。An electromagnet 17 is housed in at least one of the chambers at the ends of the container 11 partitioned by the stoppers 12 and 13 as a driving means for reciprocating the weight 14. This uses the principle of an electromagnetic plunger, and the weight 1
The weight 14 is reciprocated by applying a magnetic force to the shaft 15 extending in the vertical direction on the upper and lower surfaces of 4. A shear wave is generated by colliding the weight 14 that reciprocates up and down with the stoppers 12 and 13. The container 11 transmits a shear wave generated when the weight 14 reciprocates and collides with the stoppers 12 and 13 to a support plate 30 described later.
【００１５】本発明の剪断波発生装置の別の態様を図３
に示す。さらに、剪断波発生部１を図３のＢ−Ｂ’拡大
部分断面図である図４及び図４のＣ−Ｃ’断面図である
図５を用いて説明する。Another embodiment of the shear wave generator of the present invention is shown in FIG.
Shown in. Further, the shear wave generator 1 will be described with reference to FIG. 4 which is an enlarged partial sectional view taken along the line BB ′ of FIG. 3 and FIG. 5 which is a sectional view taken along the line CC ′ of FIG.
【００１６】容器１８は内部が中空であり、上壁には、
後述の錘１９を回転動させる駆動手段であるモーター２
０が埋め込まれ、下壁の内側中心部には錘１９の軸２１
を支持する軸受２２が有る。容器１８の内部には、回転
往復動する円板状の錘１９がこの錘１９を回転動させる
駆動手段であるモーター２０と錘１９の上下面の中心に
設けた２本の軸２１の一方を介して連結され、軸２１の
他方は軸受２２に支持されている。錘１９は上面又は下
面の円周付近に突起２３を有する。また容器１８の内面
には、突起２３と衝突するようにストッパー２４が設け
られる。ストッパー２４は、１つ又は２つ設けることが
できる。錘１９が回転することにより突起２３がストッ
パー２４に衝突して剪断波を発生する。この剪断波は、
ストッパー２４から容器１８と一体に成形された支持板
３０を介して地盤に伝えられる。The container 18 has a hollow interior, and the upper wall is
A motor 2 which is a driving means for rotating a weight 19 described later.
0 is embedded, and the shaft 21 of the weight 19 is attached to the inner center of the lower wall.
There is a bearing 22 that supports. Inside the container 18, a disk-shaped weight 19 that reciprocally rotates is provided with a motor 20 that is a driving means for rotating the weight 19 and one of two shafts 21 provided at the centers of the upper and lower surfaces of the weight 19. The other end of the shaft 21 is supported by a bearing 22. The weight 19 has a protrusion 23 near the circumference of the upper surface or the lower surface. A stopper 24 is provided on the inner surface of the container 18 so as to collide with the protrusion 23. One or two stoppers 24 can be provided. When the weight 19 rotates, the projection 23 collides with the stopper 24 and a shear wave is generated. This shear wave
It is transmitted from the stopper 24 to the ground through a support plate 30 formed integrally with the container 18.
【００１７】一方、固定手段２は、対向する一対の支持
板３０と支持板３１の間を架橋し、かつ該支持板３０及
び３１の間隔を自由に変動させることが可能な少なくと
も２つの支柱手段３２とからなる。そして、支持板３０
又は３１のいずれか一方に前記剪断波発生部１の容器１
１または１８が固定される。支柱手段３２としては、公
知の油圧ポンプや空気圧ポンプ式のジャッキ等を用いる
ことができる。また、容器１１または１８とこの容器１
１または１８を固定した支持板３０又は３１とは、一体
に成形したものでも、両者を接着したものであってもよ
い。On the other hand, the fixing means 2 bridges between a pair of support plates 30 and 31 facing each other, and at least two support means which can freely change the distance between the support plates 30 and 31. And 32. And the support plate 30
Alternatively, the container 1 of the shear wave generator 1 is provided on either one of
1 or 18 is fixed. As the support means 32, a known hydraulic pump, a pneumatic pump type jack, or the like can be used. Also, the container 11 or 18 and this container 1
The support plate 30 or 31 to which 1 or 18 is fixed may be integrally molded or may be bonded together.
【００１８】本発明の液状化強度の測定方法は、上記の
剪断波発生装置を用いて地盤の孔内で地盤に剪断波を繰
り返し与え、それにより変化する地盤内の間隙水圧を、
同様に地盤の孔内に設置した間隙水圧計により測定する
ことにより求められる。この方法を図６に従って説明す
る。The method for measuring the liquefaction strength of the present invention uses the above shear wave generator to repeatedly apply a shear wave to the ground in a hole in the ground, thereby changing the pore water pressure in the ground,
Similarly, it can be obtained by measuring with a pore pressure gauge installed in the hole in the ground. This method will be described with reference to FIG.
【００１９】剪断波発生装置１及び間隙水圧計６、さら
に必要により加速度計７を地盤１０に開けた孔９内に設
置する。剪断波発生装置１と間隙水圧計６及び加速度計
７とは一定の距離を置いて設置する。次いで、剪断波発
生装置１を用いて地盤１０に剪断波を繰り返し与え、地
盤内を伝播した剪断波により変化する間隙水圧を間隙水
圧計６により測定する。また、同時に加速度計７によ
り、剪断波による加速度を求める。但し、加速度は同時
に測定する必要はなく、予め測定しておくこともでき
る。The shear wave generator 1, the pore water pressure gauge 6, and, if necessary, the accelerometer 7 are installed in the hole 9 formed in the ground 10. The shear wave generator 1 and the pore water pressure gauge 6 and the accelerometer 7 are installed with a certain distance. Then, a shear wave is repeatedly applied to the ground 10 using the shear wave generator 1, and the pore water pressure gauge 6 measures the pore water pressure that changes due to the shear wave propagating in the ground. At the same time, the acceleration due to the shear wave is obtained by the accelerometer 7. However, the acceleration does not have to be measured at the same time, and may be measured in advance.
【００２０】このようにして測定した間隙水圧の変化か
ら、累積損傷度法を用いて、以下のようにして地盤の液
状化強度を求める。用いるパラメーターは以下の通りで
ある。 τ0 ：剪断波発生装置１から発生する剪断応力 τd ：間隙水圧測定位置の剪断応力 ｘ ：測定された加速度 Δｕ：測定された過剰間隙水圧 Ｌ ：剪断波発生装置１と間隙水圧計６との距離From the change in pore water pressure measured in this way, the liquefaction strength of the ground is obtained as follows using the cumulative damage degree method. The parameters used are as follows. τ 0 : Shear stress generated from shear wave generator 1 τ d : Shear stress at pore water pressure measurement position x: Measured acceleration Δu: Measured excess pore water pressure L: Shear wave generator 1 and pore water pressure gauge 6 The distance
【００２１】１．過剰間隙水圧Δｕ及び加速度ｘを測定
する。 ２．剪断波発生装置１の錘の質量、剪断波発生部２を固
定する支持板３０の面積、錘１４又は１９の駆動のため
に与えた電流から、剪断波発生装置１から発生する剪断
応力τ01を求める。 ３．２で求めた剪断応力τ01、予め決めてあるＬ及び１
で測定したｘから、間隙水圧測定位置での剪断応力τd1
を求める。 ４．１波の剪断波による応力τd と過剰間隙水圧の変化
量Δｕとは、図７に示すような関係があるので、３で求
めたτd1と１で測定したΔｕ1 との関係を同様にして求
め、τd1１波当たりのΔｕ1 を求める。1. Excessive pore water pressure Δu and acceleration x are measured. 2. From the mass of the weight of the shear wave generator 1, the area of the support plate 30 that fixes the shear wave generator 2, and the electric current applied to drive the weight 14 or 19, the shear stress τ 01 generated from the shear wave generator 1 is generated. Ask for. Shear stress τ 01 determined in 3.2, L and 1 determined in advance
Shear stress τ d1 at the pore water pressure measurement position from x measured in
Ask for. Since the stress τ d due to the shear wave of 4.1 waves and the change amount Δu of the excess pore water pressure have the relationship shown in FIG. 7, the relationship between τ d1 obtained in 3 and Δu 1 measured in 1 is Similarly, Δu 1 per τ d1 wave is calculated.
【００２２】５．τd1１波当たりの累積損傷度をＤn=1
td1 ＝Δｕ1 ／δv'とする。但し、δv'は間隙水圧測定
地点の有効応力である。 ６．τ0 を変化させて、１〜４の操作を繰り返し行い、
τ02、τ03における過剰間隙水圧Δｕ2 、Δｕ3 及び加
速度ｘ2 、ｘ3 を測定し、同様にしてＤn=1 td2 ＝Δｕ
2 ／δv'及びＤn=1 td3 ＝Δｕ3 ／δv'を求める。これ
らから、液状化に必要な繰り返し回数（Ｎ値）Ｎ＝δv'
／Δｕ123 を求める。 ７．応力比ＲL ＝τd123／δv'を縦軸にし、６で求めた
Ｎ＝δv'／Δｕ123 を横軸にして図８に示すような関係
を求め、この結果から地盤の液状化強度を求めることが
できる。5. τ d1 Cumulative damage per wave D n = 1
td1 = and Δu 1 / δv '. However, δv 'is the effective stress at the pore water pressure measurement point. 6. Change τ 0 and repeat steps 1 to 4,
Excess pore water pressures Δu 2 , Δu 3 and accelerations x 2 , x 3 at τ 02 , τ 03 were measured, and D n = 1 td2 = Δu in the same manner.
2 / δv 'and D n = 1 td3 = Δu 3 / δv' are obtained. From these, the number of repetitions (N value) required for liquefaction N = δv '
Calculate / Δu 123 . 7. The stress ratio R L = τ d123 / δv 'is plotted on the ordinate and the N = δv' / Δu 123 obtained on 6 is plotted on the abscissa, and the relationship as shown in FIG. 8 is obtained. You can ask.
【００２３】[0023]
【発明の効果】本発明の剪断波発生装置を用いれば、現
位置で比較的容易にかつより正確に液状化強度を測定す
るために必要な、剪断波を地盤に与えることができる。EFFECT OF THE INVENTION By using the shear wave generator of the present invention, it is possible to apply the shear wave required for measuring the liquefaction strength relatively easily and more accurately at the present position to the ground.
【００２４】さらに、本発明の方法によれば、現位置で
比較的容易にかつより正確に液状化強度を測定できる。Furthermore, according to the method of the present invention, the liquefaction strength can be measured at the present position relatively easily and more accurately.
【図１】本発明の１態様である剪断波発生装置の斜視図
である。FIG. 1 is a perspective view of a shear wave generator that is one embodiment of the present invention.
【図２】図１の装置のＡ−Ａ’拡大部分断面図である。FIG. 2 is an enlarged partial sectional view taken along the line A-A ′ of the apparatus of FIG.
【図３】本発明の１態様である剪断波発生装置の斜視図
である。FIG. 3 is a perspective view of a shear wave generator that is one embodiment of the present invention.
【図４】図３の装置のＢ−Ｂ’拡大部分断面図である。FIG. 4 is an enlarged partial sectional view taken along the line B-B ′ of the apparatus of FIG.
【図５】図４の装置のＣ−Ｃ’断面図である。5 is a cross-sectional view taken along the line C-C ′ of the apparatus of FIG.
【図６】本発明の液状化強度測定方法の説明図である。FIG. 6 is an explanatory diagram of a liquefaction strength measuring method of the present invention.
【図７】剪断波応力τd1と過剰間隙水圧Δｕ1 との関係
を示す図である。FIG. 7 is a diagram showing the relationship between shear wave stress τ d1 and excess pore water pressure Δu 1 .
【図８】液状化強度を求めるに必要な応力比ＲL ＝τ
d123／δv'とＮ＝δv'／Δｕ123 との関係を示す図であ
る。FIG. 8: Stress ratio R L = τ required to obtain liquefaction strength
d123 / .delta.v 'and N = .delta.v' is a diagram showing the relationship between / Delta] u 123.
１：剪断波発生装置 ２：剪断波発生部 ３：固定手段 ４：剪断波発生部２の電源 ５：固定手段３を稼働させるための源 ６：間隙水圧計 ７：加速度計 ８：記録装置 ９：地盤に開けた孔 １０：地盤 １１、１８：容器 １２、１３、２４：ストッパー １４、１９：錘 １５、２１：軸 １６：孔 １７：電磁石１７ ２３：突起 ３０、３１：支持板 ３２：支持手段 1: Shear wave generator 2: Shear wave generator 3: Fixing means 4: Power supply for shear wave generator 2 5: Source for operating the fixing means 3 6: Pore pressure gauge 7: Accelerometer 8: Recording device 9 : Hole in the ground 10: Ground 11, 18: Container 12, 13, 24: Stopper 14, 19: Weight 15, 21: Shaft 16: Hole 17: Electromagnet 17 23: Protrusion 30, 31: Support plate 32: Support means
Claims (2)
に開けた孔内に固定し、かつ該剪断波発生部で発生させ
た剪断波を地盤に伝える固定手段からなる、剪断波を地
盤に与える装置であって、前記剪断波発生部は、往復動
し、ストッパーに衝突することにより剪断波を発生させ
る錘、該錘を往復動させる駆動手段、並びに前記錘及び
駆動手段を収納し、内部に前記ストッパーを設け、かつ
前記錘の往復動により発生した剪断波を地盤孔の内壁に
伝えるための容器とからなり、前記固定手段は、対向す
る一対の支持板及び該支持板の間を架橋し、かつ該支持
板の間隔を変動させることが可能な少なくとも２つの支
柱手段とからなり、前記支持板のいずれか一方に前記剪
断波発生部の容器が固定されていることを特徴とする前
記装置。1. A shear wave comprising a shear wave generating part and a fixing means for fixing the shear wave generating part in a hole opened in the ground and for transmitting the shear wave generated in the shear wave generating part to the ground. A device for applying to the ground, wherein the shear wave generating section accommodates a weight that reciprocates and generates a shear wave by colliding with a stopper, a driving unit that reciprocates the weight, and the weight and the driving unit. And a container for transmitting the shear wave generated by the reciprocating movement of the weight to the inner wall of the ground hole, wherein the fixing means bridges between a pair of opposing support plates and the support plates. And at least two strut means capable of varying the distance between the supporting plates, and the container of the shear wave generating part is fixed to either one of the supporting plates. apparatus.
載の装置から地盤に剪断波を繰り返し与え、地盤内を伝
播した剪断波により変化する間隙水圧を、前記孔と同一
の孔内に上記装置から一定距離に設置した間隙水圧計に
より測定することを特徴とする地盤の液状化強度の測定
方法。2. A shear wave is repeatedly applied to the ground from the device according to claim 1, which is installed in a hole opened in the ground, and a pore water pressure that changes by the shear wave propagating in the ground is generated in the same hole as the hole. A method for measuring the liquefaction strength of the ground, which comprises measuring with a pore water pressure gauge installed at a constant distance from the above device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16511891A JPH0593416A (en) | 1991-06-10 | 1991-06-10 | Device for providing shearing wave for ground and measuring method of liquefaction strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16511891A JPH0593416A (en) | 1991-06-10 | 1991-06-10 | Device for providing shearing wave for ground and measuring method of liquefaction strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0593416A true JPH0593416A (en) | 1993-04-16 |
Family
ID=15806258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16511891A Pending JPH0593416A (en) | 1991-06-10 | 1991-06-10 | Device for providing shearing wave for ground and measuring method of liquefaction strength |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0593416A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107907295A (en) * | 2017-10-23 | 2018-04-13 | 中国地质大学（武汉） | The geotechnical centrifuge case that a kind of remote control circulating analog tsunami acts on slight slope |
| JP2018188887A (en) * | 2017-05-09 | 2018-11-29 | 国立大学法人 東京大学 | Method for estimating liquefaction strength ratio |
| US10195005B2 (en) | 2014-03-06 | 2019-02-05 | Tepe Munhygienprodukter Ab | Interdental cleaner |
| CN116211352A (en) * | 2023-03-10 | 2023-06-06 | 西安交通大学 | Head-mounted transcranial ultrasound brain tissue elasticity imaging device and imaging method |
-
1991
- 1991-06-10 JP JP16511891A patent/JPH0593416A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10195005B2 (en) | 2014-03-06 | 2019-02-05 | Tepe Munhygienprodukter Ab | Interdental cleaner |
| JP2018188887A (en) * | 2017-05-09 | 2018-11-29 | 国立大学法人 東京大学 | Method for estimating liquefaction strength ratio |
| CN107907295A (en) * | 2017-10-23 | 2018-04-13 | 中国地质大学（武汉） | The geotechnical centrifuge case that a kind of remote control circulating analog tsunami acts on slight slope |
| CN116211352A (en) * | 2023-03-10 | 2023-06-06 | 西安交通大学 | Head-mounted transcranial ultrasound brain tissue elasticity imaging device and imaging method |
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