JPH04155238A - Behavior experimenting apparatus for deep layer subsoil - Google Patents
Behavior experimenting apparatus for deep layer subsoilInfo
- Publication number
- JPH04155238A JPH04155238A JP28026590A JP28026590A JPH04155238A JP H04155238 A JPH04155238 A JP H04155238A JP 28026590 A JP28026590 A JP 28026590A JP 28026590 A JP28026590 A JP 28026590A JP H04155238 A JPH04155238 A JP H04155238A
- Authority
- JP
- Japan
- Prior art keywords
- model
- soil
- ground
- bottom plate
- behavior
- 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
- 239000000463 material Substances 0.000 claims abstract description 41
- 239000002689 soil Substances 0.000 claims abstract description 26
- 238000002474 experimental method Methods 0.000 claims description 16
- 238000006073 displacement reaction Methods 0.000 abstract description 20
- 239000004576 sand Substances 0.000 abstract description 3
- 238000010276 construction Methods 0.000 abstract 2
- 239000012528 membrane Substances 0.000 description 8
- 238000005259 measurement Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 239000004519 grease Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
- 230000036461 convulsion Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 239000012748 slip agent 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)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、深層地盤の挙動実験装置に関するものである
。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for testing the behavior of deep ground.
近年、限られた都市空間内を有効に利用するために深い
土中にまで基礎杭やトンネル等の地下構造物が建設され
ている。In recent years, underground structures such as foundation piles and tunnels have been constructed deep into the soil in order to make effective use of limited urban space.
しかし、このような拘束圧の高い深層地盤の領域での構
造物と地盤の相互作用力、地盤の変形・破壊パターン等
の基本特性に関するデータが不十分であるので実情であ
り、したがって、かかるデータを実験的に求めることが
要望とされている。However, the current situation is that there is insufficient data on basic characteristics such as interaction forces between structures and the ground, deformation and fracture patterns of the ground, etc. in areas of deep ground with high confining pressure, and therefore, such data are insufficient. It is desired to experimentally determine the
本発明は、上記の点に鑑みてなされたものであって、そ
の目的とするところは拘束圧の高い深層地盤と地中構造
物の相互作用、特に構造物前面の深層地盤の変形・破壊
パターンを実験により把握することかできる深層地盤の
挙動実験装置を提供することにある。The present invention has been made in view of the above points, and its purpose is to improve the interaction between deep ground with high confining pressure and underground structures, particularly the deformation and failure patterns of deep ground in front of structures. The purpose of this invention is to provide an experimental device for the behavior of deep ground, which can be used to understand the behavior of deep ground through experiments.
［課題を解決するための手段］
上記目的を達成するために提案された本発明の構成は次
の通りである。すなわち、
本発明の深層地盤の挙動実験装置は、可動側板。[Means for Solving the Problems] The configuration of the present invention proposed to achieve the above object is as follows. That is, the deep ground behavior experiment device of the present invention includes a movable side plate.
可動底板および固定上蓋で構成される地盤材料充填用の
土槽と、上記可動側板および上記可動底板を外側から加
圧して上記地盤材料を３軸圧縮状態にする載荷手段と、
上記土槽の略中央に配設される杭等の地下構造物模型と
、上記地下構造物模型に水平方向から載荷する載荷手段
と、上記地盤材料の挙動を観測する観測手段とを具備す
ることを特徴するものである。a soil tank for filling ground material consisting of a movable bottom plate and a fixed top cover; a loading means that pressurizes the movable side plate and the movable bottom plate from the outside to bring the ground material into a triaxially compressed state;
A model of an underground structure such as a pile placed approximately in the center of the earth tank, a loading means for horizontally loading the model of the underground structure, and an observation means for observing the behavior of the ground material. It is characterized by
本発明の深層地盤の挙動実験装置によれば、可動側板、
可動底板および固定上蓋で構成される地盤材料充填用の
土槽と、上記可動側板および上記可動底板を外側から加
圧して上記地盤材料を３軸圧縮状態にする載荷手段とを
具備するので、供試体（地盤材料）を３軸圧縮により地
中の応力状態を再現することできる。また、上記土槽の
略中央に配設される杭等の地下構造物模型と、上記地下
構造物模型に水平方向から載荷する載荷手段とを具備す
るので、地下構造物模型への載荷により、水平面内で地
下構造物模型の回りの供試体に二次元的な挙動を起こさ
せることかでき、その挙動を観測手段で観測することが
できる。According to the deep ground behavior experiment device of the present invention, a movable side plate,
The present invention is equipped with a soil tank for filling ground material consisting of a movable bottom plate and a fixed top cover, and a loading means that pressurizes the movable side plate and the movable bottom plate from the outside to bring the ground material into a triaxially compressed state. The stress state in the ground can be reproduced by triaxial compression of the specimen (ground material). Moreover, since it is equipped with an underground structure model such as a pile placed approximately in the center of the earth tank and a loading means for loading the underground structure model from the horizontal direction, by loading the underground structure model, It is possible to cause the specimen around the underground structure model to behave two-dimensionally in a horizontal plane, and this behavior can be observed using observation means.
以下、本発明の深層地盤の挙動実験装置を図示の実施例
に基ついて説明する。EMBODIMENT OF THE INVENTION Below, the deep ground behavior experiment apparatus of the present invention will be explained based on the illustrated embodiment.
第１図および第２図は挙動実験装置の全体図を示してお
り、図中１は地盤材料Ａを充填する土槽１であって、固
定上蓋１ａとそれぞれが板面に対して垂直方向に移動可
能となった可動側板１ｂ及び可動底板１ｃとで構成され
ている。隣合う可動側板１ｂ同士は耐圧性を有する可撓
性材料を介して連結され、固定上蓋１ａの上面には変形
防止用のリブ材１ｅか形成され、可動底板１ｃは底板枠
ｌｄに嵌め込まれている。Figures 1 and 2 show the overall diagram of the behavior experiment equipment, in which 1 is a soil tank 1 filled with ground material A, and a fixed upper lid 1a and each are vertically connected to the plate surface. It is composed of a movable side plate 1b and a movable bottom plate 1c. Adjacent movable side plates 1b are connected to each other via a pressure-resistant flexible material, a rib material 1e for preventing deformation is formed on the upper surface of the fixed upper lid 1a, and the movable bottom plate 1c is fitted into the bottom plate frame ld. There is.
土槽１の外周には外枠２か配設されており、この外枠２
は底フレーム２ａと側フレーム２ｂとで構成されている
。外枠２の底フレーム２ａには土槽ｌの可動底板ＩＣを
押圧するための上下圧載荷用ジヤツキ（載荷手段）３か
、外枠２の側フレーム２ｂには土槽１の可動側板１ｂを
押圧するための水平載荷用ジヤツキ（載荷手段）４かそ
れぞれ取付けられている。そして、これらのジヤツキ３
゜４により可動底板１ｃおよび可動側板１ｂを押圧して
供試体を３軸圧縮状態におくことができる。An outer frame 2 is arranged around the outer periphery of the soil tank 1, and this outer frame 2
is composed of a bottom frame 2a and a side frame 2b. The bottom frame 2a of the outer frame 2 is equipped with a vertical pressure loading jack (loading means) 3 for pressing the movable bottom plate IC of the soil tank l, and the side frame 2b of the outer frame 2 is equipped with a movable side plate 1b of the soil tank 1. A horizontal loading jack (loading means) 4 for pressing is attached to each. And these jerks 3
4, the movable bottom plate 1c and the movable side plate 1b can be pressed to place the specimen in a triaxially compressed state.
ジヤツキ３，４にはロードセル（圧力センサ）３Ａ、４
Ａか取付けられて水平及び鉛直方向の拘束力を計測を可
能にしている。Load cells (pressure sensors) 3A and 4 are installed on jacks 3 and 4.
A is attached to make it possible to measure the restraining force in the horizontal and vertical directions.
土槽ｌは外枠２の底フレーム２ａから立設される支柱５
にて支持されており、この支柱５には土槽１の固定上蓋
１ａと底板枠１ｄか固定され、固定上蓋１ａは連結棒５
ａを介して支柱５に着脱自在に取付けられている。The earthen tank l has a support 5 erected from the bottom frame 2a of the outer frame 2.
The fixed upper cover 1a and bottom plate frame 1d of the earthen tank 1 are fixed to this support 5, and the fixed upper cover 1a is supported by a connecting rod 5.
It is detachably attached to the support column 5 via a.
６は杭模型（地下構造物模型）であって、第３図に示す
ように模型支持体７にて支持さ゛れている。Reference numeral 6 denotes a pile model (underground structure model), which is supported by a model support 7 as shown in FIG.
杭模型６の上端は固定上蓋１ａに摺動自在に接触し、杭
模型の下端にはねし棒６ａか杭模型６と同軸にして設け
られ、このねじ棒６ａは可動底板ＩＣの中央貫通孔８に
挿通されるとともに、後述する水平載荷方向への移動を
妨げないようにして摺動板７ａを介して模型支持体７の
取付けられている。摺動板７ａは模型支持体７にベアリ
ング７ｂを介して水平方向に移動自在に取付けられてお
り、杭模型６に水平方向の載荷か加わると載荷方向に移
動できる構成となっている。The upper end of the pile model 6 is slidably in contact with the fixed upper cover 1a, and a screw rod 6a is provided at the lower end of the pile model or coaxially with the pile model 6, and this threaded rod 6a is inserted into the center through hole of the movable bottom plate IC. 8, and the model support 7 is attached via a sliding plate 7a so as not to impede movement in the horizontal loading direction, which will be described later. The sliding plate 7a is attached to the model support 7 via a bearing 7b so as to be movable in the horizontal direction, and is configured to be able to move in the loading direction when a horizontal load is applied to the pile model 6.
第１図および第２図中９は杭模型６に水平方向に載荷す
る水平載荷用アクチュエータであって、外枠２の側フレ
ーム２ｂに取付けられ、水平載荷用アクチュエータ９の
ロット９ａは可動側板１ｂの貫通孔１０から土槽ｌ内に
突出し、ロッド９ａの先端は抗模型６の中間部に取着さ
れている。杭模型６の外周面には、第４図のように土圧
計６Ａ及びせん断力針６Ｂが装着されている。杭模型６
の下端の近傍には変位計６０か取付けらで杭の変位の計
測を可能にしている２
一方、アクチュエータ９にはロードセル（圧力センサ）
９Ａか取付けられ、またアクチュエータ９のロット９ａ
にはひすみゲージか取付けられている。1 and 2 is a horizontal loading actuator that loads the pile model 6 in the horizontal direction, and is attached to the side frame 2b of the outer frame 2, and the lot 9a of the horizontal loading actuator 9 is the movable side plate 1b. The rod 9a protrudes from the through hole 10 into the soil tank l, and the tip of the rod 9a is attached to the middle part of the resisting model 6. An earth pressure gauge 6A and a shear force needle 6B are attached to the outer peripheral surface of the pile model 6, as shown in FIG. Pile model 6
A displacement meter 60 is installed near the bottom end of the pile, making it possible to measure the displacement of the pile2.On the other hand, a load cell (pressure sensor) is attached to the actuator 9.
9A installed and also actuator 9 lot 9a
A strain gauge is installed.
土槽ｌの固定上蓋１ａの下面と可動底板１ｂ及び底板枠
１ｃの上面にはラテックスメンブレンＢか張設されてい
る。A latex membrane B is stretched over the lower surface of the fixed upper lid 1a, the movable bottom plate 1b, and the upper surface of the bottom plate frame 1c of the earthen tank l.
なお、実験を行う際には固定上蓋１ａとメンブレンＢの
間、可動底板１ｃ及び固定底枠１ｄとメンブレンＢの間
にはそれぞれグリース等により、滑り剤層Ｃが形成され
て土層ｌと供試体（地盤材料）Ａとの間の摩擦を低減し
て供試体Ａの深さ方向の挙動が一様となるように構成さ
れている。In addition, when conducting the experiment, a slip agent layer C is formed using grease or the like between the fixed top cover 1a and the membrane B, and between the movable bottom plate 1c, the fixed bottom frame 1d, and the membrane B, and the layer C is connected to the soil layer l. It is configured to reduce friction with the specimen (ground material) A so that the behavior of the specimen A in the depth direction becomes uniform.
第１図および第２図中１０は地盤材料の変形・破壊パタ
ーンを観測する観測手段であって、供試体Ａと固定上蓋
１ａとの間に介在するメンブレンＡには、網目の単位寸
法が１ ｃｍＸｌ ｃｍのメツシュ模様の印刷かされ、
この印刷部に対応して固定上蓋１ａに観測窓１０ａを形
成することにより、地下構造物模型６とその周辺地盤材
料の挙動の観測を可能にしている。観測窓１０ａは固定
上蓋１ａに形成された開口部に透明アクリル樹脂板を嵌
め込んで構成されている。Reference numeral 10 in FIGS. 1 and 2 is an observation means for observing the deformation/destruction pattern of the ground material, and the membrane A interposed between the specimen A and the fixed upper cover 1a has a mesh unit size of 1. Printed with a mesh pattern of cmXl cm,
By forming an observation window 10a in the fixed upper cover 1a corresponding to this printing part, it is possible to observe the behavior of the underground structure model 6 and surrounding ground materials. The observation window 10a is constructed by fitting a transparent acrylic resin plate into an opening formed in the fixed upper lid 1a.
なお、実験の際には地盤材料の土中に土中変位計１１が
埋設されるものである。In addition, during the experiment, the soil displacement meter 11 is buried in the soil of the ground material.
次に、以上の深層地盤の挙動実験装置（土槽の寸法；
１．６ｍＸ１．６ｍＸ０．５ｍ、杭模型の直径；ｌＯｃ
ｍ）を用いた地盤材料の変形・破壊パターンの実験方法
を説明する。Next, the above-mentioned deep ground behavior experiment equipment (soil tank dimensions;
1.6mX1.6mX0.5m, diameter of pile model; lOc
We will explain the experimental method of deformation and fracture patterns of ground materials using m).
本実験では、摩擦が卓越した材料（φ材）と、粘着力が
卓越した材料（Ｃ材）の２種類の地盤材料Ａについて実
験を行った。φ材としては、材料自体の安全性等を考慮
して豊浦標準砂を使用し、Ｃ材としては所定の強度を得
るために粉末粘土と早強セメントを混合して養生期間を
与えたものを使用した。In this experiment, two types of ground materials A were used: a material with excellent friction (φ material) and a material with excellent adhesive strength (C material). For the φ material, Toyoura standard sand was used in consideration of the safety of the material itself, and for the C material, powdered clay and early strength cement were mixed and given a curing period to obtain the specified strength. used.
また、拘束圧の設定にあたっては、原地盤における最大
有効被りｚ＝２５ｍ、地盤の単位体積重量７＝２．
Ｏｔ ｆ／ｒｄ、縮尺１／ｌＯを想定し、最大上載圧＝
ｚ ・７／１０＝５． Ｏｔ ｆ／ｌｎ’にした。In addition, when setting the confining pressure, the maximum effective cover in the original ground z = 25 m, the unit volume weight of the ground 7 = 2.
Assuming Ot f/rd, scale 1/lO, maximum overload pressure =
z ・7/10=5. I set it to Ot f/ln'.
また、拘束圧が高い領域においては一般に相対密度およ
び一軸圧縮強度ｑが大きいと考えられることから、φ材
については密な砂を想定して相対密度を７０％とし、Ｃ
材については拘束圧載荷時に供試体か破壊しないように
ｑ＝６．０ｔｆ／ｍとした。In addition, since it is generally considered that the relative density and unconfined compressive strength q are large in areas with high confining pressure, the relative density of the φ material is assumed to be 70%, assuming dense sand, and C
Regarding the material, q was set to 6.0 tf/m so that the specimen would not be destroyed during confining pressure loading.
以下、第７図に示す実験手順に従って説明する。The following will explain the experimental procedure shown in FIG.
（１）供試体の作成
■土槽底板の上面にグリースを塗布してメンブレンＢを
張設する。(1) Preparation of specimen ■Apply grease to the top of the soil tank bottom plate and affix membrane B.
■次に、杭模型６を据え付けた後、土槽１内に地盤材料
Ａを入れて供試体を作成する。■Next, after installing the pile model 6, the ground material A is placed in the soil tank 1 to create a specimen.
■−１φ材による供試体の作成方法
ホッパによる気中落下法で所定の相対密度を持つ供試体
を作成した。相対密度は、ホッパーの開口幅、ホッパー
の速度、落下高さに影響されるが、各パラメーターは予
備試験により、ホッパーの速度＝ １２． ５ｃｍ／ｓ
ｅ ｃ、ホッパーの開口幅＝３ｍｍ、落下高さ一６１
ｃｍとした。■Method for creating specimens using -1φ material Specimens having a predetermined relative density were created by the air drop method using a hopper. The relative density is affected by the hopper opening width, hopper speed, and falling height, but each parameter was determined by preliminary tests to be hopper speed = 12. 5cm/s
e c, hopper opening width = 3mm, falling height -61
cm.
■−２０材による供試体の作成方法
配合及び養生期間は、予備試験（−軸圧縮試験）により
決定し、その配合を１ボ当たり粘土７１４ｋｇｆ、セメ
ント９０ｋｇｆ、水７１４ｋｇｆとし、養生期間を７２
時間とした。■ Method for preparing specimens using -20 material The composition and curing period were determined by a preliminary test (-axial compression test).
It was time.
■固定上蓋１ａは、その下面にグリースＣを塗布してメ
ンブレンＢを張設したのち実験装置にセットした。(2) The lower surface of the fixed upper lid 1a was coated with grease C and membrane B was stretched over it, and then set in the experimental apparatus.
（２）拘束圧載荷
拘束圧載荷にあたっては、［水平荷重を受ける地中構造
物の周囲の深層地盤は水平面内で二次元挙動を示す」と
いう−船釣仮定の下、まず上載圧を所定の大きさまで作
用させ、その後水平圧を作用させることにより供試体を
３軸方向から圧縮して地中の応力状態を再現した。作用
圧の大きさはジヤツキ３，４に設けたロードセル３Ａ、
４Ａにより計測して載荷荷重を管理し、また杭模型６の
周囲に設置した土圧計６Ａにより計測される土圧分布も
同時に計測した。なお、所定の拘束圧載荷後、ストロー
ク変動防止装置により杭模型への水平載荷中のストロー
クの変動を防止した。（３）杭の水平載荷
杭模型６に対してアクチュエータ９にて静的な片押しに
よる載荷を行った。(2) Confined Pressure Loading When confining pressure loading is carried out, we first set the overburden pressure at a predetermined level based on the assumption that ``the deep ground around underground structures subjected to horizontal loads exhibits two-dimensional behavior in the horizontal plane.'' The specimen was compressed from three axial directions by applying horizontal pressure to reproduce the stress state in the ground. The magnitude of the working pressure is determined by the load cell 3A installed on the jacks 3 and 4.
4A to manage the applied load, and the earth pressure distribution measured by the earth pressure gauge 6A installed around the pile model 6 was also measured at the same time. After loading the pile model with a predetermined confining pressure, a stroke fluctuation prevention device was used to prevent stroke fluctuations during horizontal loading of the pile model. (3) Horizontal loading of piles The pile model 6 was loaded by static one-sided pushing using the actuator 9.
載荷パターンは第８図に示す通りである。なお、載荷ス
テップは０． １〜０．５ｔＬ載荷速度は載荷ステップ
当たり１分間、載荷保持時間は３分とした。The loading pattern is as shown in FIG. Note that the loading step is 0. The loading rate of 1 to 0.5 tL was 1 minute per loading step, and the loading holding time was 3 minutes.
（４）計測
■拘束圧載荷によりジヤツキ３，４による荷重と杭模型
６周辺の土圧を計測した。この場合の計測間隔は、約４
秒間隔で計測してデイスプレィに表示した。(4) Measurement ■ The load due to jacks 3 and 4 and the earth pressure around the pile model 6 were measured by restraint pressure loading. In this case, the measurement interval is approximately 4
It was measured every second and displayed on the display.
■杭模型６への水平載荷により地盤変位、杭模型６の変
位、杭載荷荷重、杭周面土圧、杭周面摩擦および土中変
位を計測した。この場合の計測間隔は、地盤変位につい
ては偶数ステップ終了時にメンブレンＢのメツシュ印刷
部の変位を観測窓１０ａを通して写真撮影した。杭模型
６の変位、杭載荷荷重、杭周面土圧、杭周面摩擦および
土中変位の計測間隔については各ステップ終了時から次
ステツプ開始まで載荷保持時間（３分間）の間に、４回
（ステップ終了時、ステップ終了時から１分、２分およ
び３分経過後の計４回）の計測を行った。■By horizontally loading the pile model 6, ground displacement, displacement of the pile model 6, pile loading load, pile circumferential earth pressure, pile circumferential surface friction, and displacement in the soil were measured. In this case, the measurement interval was such that the displacement of the mesh printed portion of the membrane B was photographed through the observation window 10a at the end of even-numbered steps. Regarding the measurement intervals of the displacement of the pile model 6, the pile load, the soil pressure on the pile circumference, the friction on the pile circumference, and the displacement in the soil, from the end of each step to the start of the next step, during the load holding time (3 minutes), Measurement was performed twice (at the end of the step, and a total of four times after 1 minute, 2 minutes, and 3 minutes had elapsed from the end of the step).
撮影された観測写真から変位測定機（デジタイザー等）
を用いてメイブレンＢの網目印刷部の各節点の座標を求
め、各節点の変位により網目毎のひずみを算定して地盤
のひずみ分布を求めて地盤の応力状態を推定し、また網
目印刷部の不連続的な変化点およびひずみ分布から地盤
の応力状況、 、破壊パターンを推定した。Using a displacement measuring device (digitizer, etc.) from the observation photos taken
The coordinates of each node of the mesh printing part of Mable B are determined using The ground stress situation, , and fracture pattern were estimated from the discontinuous change points and strain distribution.
また、アクチュエータ９のロッド９ａに設けたひずみゲ
ージから得られた変位と観測写真から得られた供試体Ａ
表面の変位とを比較して、地盤の深さ方向の挙動の一様
性を確認した。In addition, the displacement obtained from the strain gauge provided on the rod 9a of the actuator 9 and the specimen A obtained from the observation photograph.
We confirmed the uniformity of the behavior of the ground in the depth direction by comparing it with the surface displacement.
以上の実験から、次に述べるような高拘束圧下における
杭前面地盤の基本的な破壊パターンを判明した。From the above experiments, we found the basic failure pattern of the ground in front of piles under high confining pressure, as described below.
■φ材における荷重と変位の関係は直線的であり、明確
なピーク荷重は認められなかった。また、剛性は初期拘
束圧に比例した。■The relationship between load and displacement in the φ material was linear, and no clear peak load was observed. Moreover, the stiffness was proportional to the initial confining pressure.
■Ｃ材においては、杭径の３〜５％の変位で折れ点が認
められたが、変位の増大に伴い荷重は増加した。また、
剛性は初期拘束圧に依存しなかった。(2) In material C, a breaking point was observed at a displacement of 3 to 5% of the pile diameter, but the load increased as the displacement increased. Also,
The stiffness did not depend on the initial confining pressure.
■変位か杭径の１０％を超えた時点で、φ材、Ｃ材とも
すべり面の発生が確認できた。■When the displacement exceeded 10% of the pile diameter, the occurrence of a slip surface was confirmed for both φ and C materials.
すべり面は荷重の増加とともに杭模型の前面の前方に進
展し、最終的には第９図のようにくさび状のすべり面イ
と載荷方向のすべり面口の２種類で構成されるようにな
った。なお、第９図中δ１は杭模型６の変位を示し、δ
２は地盤材料Ａの変位を示す。As the load increases, the sliding surface progresses forward to the front of the pile model, and eventually it consists of two types: a wedge-shaped sliding surface A and a sliding surface opening in the loading direction, as shown in Figure 9. Ta. In addition, δ1 in FIG. 9 indicates the displacement of the pile model 6, and δ
2 indicates the displacement of ground material A.
■杭前面のひずみは、次のような分布を示した。■The strain at the front of the pile showed the following distribution.
１）すべり面は最大主ひずみ方向から３０°〜５０°か
たむいた方向に、せん断ひずみが卓越した部分に生じた
。特にＣ材および拘束圧の大きいφ材については、すべ
り面口のひずみが卓越した。1) The slip plane was tilted 30° to 50° from the direction of maximum principal strain, and occurred in the area where shear strain was predominant. In particular, for the C material and the φ material with large confining pressure, the strain at the opening of the sliding surface is outstanding.
２）すべり面口の内側では載荷方向の圧縮ひずみが卓越
し、すべり面口の外側では圧縮ひずみはほとんど生じな
かった。2) Compressive strain in the loading direction was predominant inside the sliding surface opening, and almost no compressive strain occurred outside the sliding surface opening.
■以上のことから、杭前面地盤の応力状態は、左右のす
べり面の外側においては圧縮応力が卓越していると考え
られる。すべり面上のせん断強度かクーロンのせん断抵
抗則に従うとすれば、すべり面口が逐次前方に進展して
いることから、前記■、■に示した挙動も理解できる。■From the above, it is considered that the stress state of the ground in front of the pile is dominated by compressive stress on the outside of the left and right sliding surfaces. If the shear strength on the slip surface follows Coulomb's shear resistance law, the behavior shown in (1) and (3) above can also be understood because the slip surface mouth is progressively progressing forward.
したがって、すべり面■および■が設定できれば応力の
つり合い条件・幾何学的条件・構成則により地盤反力と
変位の関係の定式化が可能となり、深い地中内の杭の地
盤反力特性を地盤の破壊パターンと関連付けて、土の変
形係数とせん断強度を用いて一貫して取り扱えることに
なる。Therefore, if slip planes ■ and ■ can be set, it becomes possible to formulate the relationship between ground reaction force and displacement using stress balance conditions, geometric conditions, and constitutive laws. It can be treated consistently using the soil's deformation coefficient and shear strength in relation to the fracture pattern of the soil.
上記の説明からも明らかなように本発明の深層地盤の挙
動実験装置によれば、供試体（地盤材料）を３軸方向か
らの圧縮により地中の応力状態を再現することができる
ので、深層地盤の変形・破壊パターンを実験的に把握す
ることかできるという効果を奏する。As is clear from the above explanation, according to the deep ground behavior experiment device of the present invention, it is possible to reproduce the stress state in the ground by compressing the specimen (ground material) from three axial directions. This has the effect of making it possible to experimentally understand the deformation and fracture patterns of the ground.
第１図および第２図は本発明の深層地盤の挙動実験装置
の実施例を示す平面図および側断面図、第３図は地中構
造物模型の支持部分の側断面図、第４図は地中構造物（
杭）模型の側面図、第５図（ａ）（ｂ）（ｃ）は第４図
のＡ−Ａ線、Ｂ−Ｂ線およびＣ−Ｃ線の断面図、第６図
は地盤材料を充填した実験装置の部分拡大断面図、第７
図は実験の順序を示すフローチャート、第８図は地中構
造物模型への水平載荷パターンを示す図、第９図は地中
構造物模型の前面におけるすべり面の発生状況を示す平
面図である。
（符号の説明）
１・・・土槽
１ａ・・・固定上蓋
１ｂ・・・可動側板
ｌｃ・・・可動底板
３・・・上下圧載荷用ジヤツキ（載荷手段）４・・・水
平載荷用ジヤツキ（載荷手段）６・・・杭模型（地下構
造物模型）
ｌＯ・・・観測手段
１０ａ・・・観測窓
Ａ・・・地盤材料
Ｂ・・・メンブレン1 and 2 are a plan view and a side sectional view showing an embodiment of the deep ground behavior experiment device of the present invention, FIG. 3 is a side sectional view of the supporting part of the underground structure model, and FIG. Underground structures (
Figure 5 (a), (b), and (c) are cross-sectional views taken along lines A-A, B-B, and C-C in Figure 4. Figure 6 is a side view of the pile model. Figure 6 is a side view of the model. Partially enlarged sectional view of the experimental equipment, No. 7
The figure is a flowchart showing the order of the experiment, Figure 8 is a diagram showing the horizontal loading pattern on the underground structure model, and Figure 9 is a plan view showing the occurrence of a slip surface on the front side of the underground structure model. . (Explanation of symbols) 1...Soil tank 1a...Fixed top lid 1b...Movable side plate lc...Movable bottom plate 3...Vertical pressure loading jack (loading means) 4...Horizontal loading jack (Loading means) 6... Pile model (underground structure model) lO... Observation means 10a... Observation window A... Ground material B... Membrane
Claims (1)
地盤材料充填用の土槽と、上記可動側板および上記可動
底板を外側から加圧して上記地盤材料を３軸圧縮状態に
する載荷手段と、上記土槽の略中央に配設される杭等の
地下構造物模型と、上記地下構造物模型に水平方向から
載荷する載荷手段と、上記地盤材料の挙動を観測する観
測手段とを具備することを特徴とする深層地盤の挙動実
験装置。(1) A soil tank for filling ground material consisting of a movable side plate, a movable bottom plate, and a fixed top cover, and a loading means that pressurizes the movable side plate and the movable bottom plate from the outside to bring the ground material into a triaxially compressed state. , comprising a model of an underground structure such as a pile arranged approximately in the center of the earth tank, a loading means for horizontally loading the model of the underground structure, and an observation means for observing the behavior of the ground material. A deep ground behavior experiment device characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28026590A JPH04155238A (en) | 1990-10-17 | 1990-10-17 | Behavior experimenting apparatus for deep layer subsoil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28026590A JPH04155238A (en) | 1990-10-17 | 1990-10-17 | Behavior experimenting apparatus for deep layer subsoil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04155238A true JPH04155238A (en) | 1992-05-28 |
Family
ID=17622589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28026590A Pending JPH04155238A (en) | 1990-10-17 | 1990-10-17 | Behavior experimenting apparatus for deep layer subsoil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04155238A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104089811A (en) * | 2014-07-24 | 2014-10-08 | 感知技术无锡有限公司 | Method and device for detecting shell structure of terrestrial magnetism vehicle detector |
| CN107918001A (en) * | 2017-11-06 | 2018-04-17 | 东华理工大学 | Ground collective model experimental box |
| JP2020012362A (en) * | 2018-07-13 | 2020-01-23 | 浙江大学Ｚｈｅｊｉａｎｇ Ｕｎｉｖｅｒｓｉｔｙ | Dynamic response time space reconstruction device |
| CN111426494A (en) * | 2020-03-26 | 2020-07-17 | 山东大学 | Lifting arm rack for model test system and working method |
| JP2022542132A (en) * | 2020-06-01 | 2022-09-29 | 浙江大学 | Test equipment and test method for simulating the effect on bearing performance of pile foundation due to the presence of cavities at pile ends |
-
1990
- 1990-10-17 JP JP28026590A patent/JPH04155238A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104089811A (en) * | 2014-07-24 | 2014-10-08 | 感知技术无锡有限公司 | Method and device for detecting shell structure of terrestrial magnetism vehicle detector |
| CN107918001A (en) * | 2017-11-06 | 2018-04-17 | 东华理工大学 | Ground collective model experimental box |
| JP2020012362A (en) * | 2018-07-13 | 2020-01-23 | 浙江大学Ｚｈｅｊｉａｎｇ Ｕｎｉｖｅｒｓｉｔｙ | Dynamic response time space reconstruction device |
| CN111426494A (en) * | 2020-03-26 | 2020-07-17 | 山东大学 | Lifting arm rack for model test system and working method |
| JP2022542132A (en) * | 2020-06-01 | 2022-09-29 | 浙江大学 | Test equipment and test method for simulating the effect on bearing performance of pile foundation due to the presence of cavities at pile ends |
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