JP2551800B2 - Pile loading test method and device - Google Patents
Pile loading test method and deviceInfo
- Publication number
- JP2551800B2 JP2551800B2 JP62327169A JP32716987A JP2551800B2 JP 2551800 B2 JP2551800 B2 JP 2551800B2 JP 62327169 A JP62327169 A JP 62327169A JP 32716987 A JP32716987 A JP 32716987A JP 2551800 B2 JP2551800 B2 JP 2551800B2
- Authority
- JP
- Japan
- Prior art keywords
- pile
- pressure
- jack
- tip
- loading
- 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
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
- Testing Or Calibration Of Command Recording Devices (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、反力杭や連結梁等を用いることなく、試験
杭のみで支持力を評価することができる、杭の載荷試験
方法及びその装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pile load test method and a load test method therefor capable of evaluating a bearing capacity only by a test pile without using a reaction pile or a connecting beam. It relates to the device.
［従来の技術］ 一般に、杭の載荷試験方法及びその装置は、第９図及
び第10図に示すように、４点に沈設した反力杭101の上
端を、図示のように連結梁102でＨ状に連結し、中央の
連結梁102の中心部下方に、ジャッキ103を介して試験用
の杭104を設置して、そのジャッキ103に圧力を加えて、
試験用の杭104の上端と反力杭101の上端の変位を測定
し、その変位量と、ジャッキ103の圧力と面積から算出
した杭104に作用している荷重から、杭104の支持力を評
価するようになっていた。[Prior Art] Generally, as shown in FIGS. 9 and 10, the pile loading test method and apparatus are such that the upper end of a reaction pile 101 sunk at four points is connected by a connecting beam 102 as shown in the figure. Connecting in an H-shape, installing a test pile 104 via the jack 103 below the central portion of the central connecting beam 102, applying pressure to the jack 103,
The displacement of the upper end of the test pile 104 and the upper end of the reaction force pile 101 was measured, and from the displacement amount and the load acting on the pile 104 calculated from the pressure and area of the jack 103, the supporting force of the pile 104 was determined. It was supposed to be evaluated.
［発明が解決しようとする問題点］ ところが、近年は杭径が太くなり、設計支持力が大き
く、載荷重が大となるため、杭の載荷試験装置が大がか
りとなり、試験コストが高くなるという欠点があった。[Problems to be Solved by the Invention] However, in recent years, the pile diameter has become thicker, the design bearing capacity has become larger, and the loading capacity has increased, so that the pile loading test equipment has become large in scale, and the test cost has increased. was there.
又、埋込み杭や場所打ち杭では、土質柱状図と杭打設
機械の電流値との比較により、支持層を確認するだけ
で、載荷試験を行うケースが少なく、十分な設計支持力
が得られているかどうか確認されていない欠点があっ
た。In addition, for embedded piles and cast-in-place piles, by comparing the soil column diagram with the current value of the pile-driving machine, it is possible to obtain sufficient design bearing capacity by only confirming the support layer and conducting load tests in few cases. There was a drawback that was not confirmed.
又、米国特許第4614110号にはジャッキを用いたもの
が提案されているが、この方式は杭先端支持力と周面摩
擦力のどちらか小さい方までしか載荷できない上、杭先
端を閉じた（先端閉塞の）杭には利用できるが、杭先端
の載荷用のジャッキが杭中空部を閉じているので、杭中
空部をオーガが通る中掘り工法や杭先端を開放して設置
する杭には適用できないという問題点があった。Also, in U.S. Pat.No. 4,614,110, a jack is proposed, but this method can load only up to the smaller one of the pile tip supporting force and the peripheral frictional force, and the pile tip is closed ( Although it can be used for piles (blocked at the tip), the jack for loading at the tip of the pile closes the hollow part of the pile. There was a problem that it could not be applied.
又、特開昭61-250219号公報には、杭の外側に杭との
摩擦が生じないようにした外管を地盤内に沈設し、この
外管と地盤を固定液等で固定して、外管の周面摩擦力を
反力とすると共に、外管に引張部材を取付け、杭頭との
間に載荷用のジャッキを介装して杭頭を下方に載荷し、
杭の先端支持力を直接測定するようにしたものが提案さ
れているが、この方式は、杭先端の支持力を外管の周面
摩擦力の範囲内で推定できるメリットはあるが、杭先端
の支持力が外管の周面摩擦力より大きい場合には杭先端
の支持力まで載荷できないこと及び、杭の周面摩擦力は
測定でないという欠点があった。Further, in JP-A-61-250219, an outer pipe that prevents friction with the pile on the outside of the pile is sunk in the ground, and the outer pipe and the ground are fixed with a fixing liquid or the like. The peripheral surface frictional force of the outer pipe is used as a reaction force, a tension member is attached to the outer pipe, and a jack for loading is provided between the outer pipe and the pile head to load the pile head downward.
Although a method has been proposed in which the bearing capacity of the pile tip is directly measured, this method has the merit that the bearing capacity of the pile tip can be estimated within the range of the peripheral frictional force of the outer pipe. When the bearing force of the pile is larger than the frictional force of the outer surface of the outer tube, the bearing force of the pile tip cannot be loaded, and the circumferential frictional force of the pile is not measured.
本発明は上記従来の欠点に鑑みて提案されたもので、
反力杭や連結梁を用いることなく、杭の周面摩擦力を測
定することができ、試験用の杭のみで簡単に支持力を評
価することができると共に、載荷用のジャッキの回収が
可能で、先端が閉塞されている杭でも、開放されている
杭へも適用し得る、杭の載荷試験方法及びその装置を提
供せんとするものである。The present invention has been proposed in view of the above-mentioned conventional drawbacks,
It is possible to measure the peripheral frictional force of piles without using reaction piles or connecting beams, and it is possible to easily evaluate the supporting force with only the piles for testing and to collect the jacks for loading. Thus, the present invention provides a pile loading test method and a pile loading test method which can be applied to a pile whose tip is closed or an pile which is open.
［問題点を解決するための手段］ 本発明は上記問題点を解決するために、所定深度に沈
設された中空の杭内に、下端に底面を押圧面とする押込
み用のジャッキを有すると共に、上端に上面を受圧面と
する着脱自在な載荷用ジャッキを有する送圧管を挿入
し、その載荷用のジャッキの上面を、杭の上端に引抜き
棒を介して着脱自在に固定された受圧板に当接せしめた
状態で、送圧管を介して両ジャッキに圧力を加えて、ジ
ャッキの押圧面と杭頭の変位を個別に測定し、各々の変
位量とジャッキの圧力と面積から算出した杭に作用して
いる荷重から、杭の支持力を評価するようにしたもの
で、上記杭の載荷試験方法を実施するために、中空の杭
と、その杭の上端に引抜き棒を介して着脱自在に固定さ
れた受圧板と、その杭内に挿入される送圧管と、送圧管
の下端に取付けられた底面を押圧面とする押込み用のジ
ャッキと、送圧管の上端に取付けられて、受圧板と当接
する、上面を受圧面とする着脱自在な載荷用のジャッキ
と、送圧管を介して両ジャッキに圧力を加える加圧手段
と、ジャッキの押圧面及び杭頭の変位を個別に測定する
変位測定手段を設けて、杭の載荷試験装置を構成し、望
ましくは、杭の側面に、外方に突出可能な摩擦力増加用
突起が設けられ、先端閉塞杭の場合には、杭の先端に先
端閉塞板を取付け、先端開放杭の場合にはそのまま、あ
るいは杭の先端に、半開放の先端シューを取付けるよう
にし、場合によっては、押込み用のジャッキが送圧管と
一体的に移動し得るように取付けられていることを特徴
とするものである。[Means for Solving the Problems] In order to solve the above problems, the present invention has a jack for pushing the bottom surface as a pressing surface at the lower end in a hollow pile sunk at a predetermined depth, Insert a pressure-feeding pipe having a detachable loading jack with the upper surface as the pressure receiving surface at the upper end, and attach the upper surface of the loading jack to the pressure receiving plate that is detachably fixed to the upper end of the pile via a pull-out rod. While in contact with each other, pressure is applied to both jacks via the pressure feed pipe, the displacements of the pressing surface of the jack and the pile head are individually measured, and it acts on the pile calculated from each displacement amount and the pressure and area of the jack. It is designed to evaluate the bearing capacity of the pile from the applied load, and in order to carry out the above-mentioned pile loading test method, it is detachably fixed to the hollow pile and the upper end of the pile via a pull-out rod. Pressure receiving plate and pressure pipe inserted in the pile A jack for pushing the bottom surface of the pressure-feeding tube as a pressing surface, and a detachable loading jack with the top surface as a pressure-receiving surface, which is attached to the upper end of the pressure-feeding tube and contacts the pressure receiving plate. , A pressurizing means for applying pressure to both jacks via a pressure-feeding pipe, and a displacement measuring means for individually measuring the displacement of the pressing surface of the jack and the pile head, constitute a pile loading test device, and preferably, A protrusion for increasing frictional force that can project outward is provided on the side of the pile.In the case of a tip closed pile, attach a tip closing plate to the tip of the pile. It is characterized in that a semi-open tip shoe is attached to the tip, and in some cases, a pushing jack is attached so as to be able to move integrally with the pressure feed pipe.
［作用］ 本発明によれば、中空の杭を所定深度に沈設し、その
杭内に下端に押込み用のジャッキを有すると共に、上端
に載荷用のジャッキを有する送圧管を挿入し、載荷用の
ジャッキの受圧面を杭の上端に固定された受圧板に当接
させて、送圧管を介し、両ジャッキに圧力を加えると、
ジャッキによる載荷重は、杭の周面においては周辺土と
の周面摩擦力により支持され、杭の下端においては、先
端地盤の支持力により支持されることになる。[Operation] According to the present invention, a hollow pile is sunk to a predetermined depth, and a pressure-feeding pipe having a jack for pushing at the lower end and a jack for loading at the upper end is inserted into the pile for loading. When the pressure receiving surface of the jack is brought into contact with the pressure receiving plate fixed to the upper end of the pile and pressure is applied to both jacks via the pressure feeding pipe,
The load applied by the jack is supported by the peripheral surface frictional force with the surrounding soil on the peripheral surface of the pile, and is supported by the supporting force of the tip ground at the lower end of the pile.
従って、ジャッキの押圧面と杭頭の変位を個別に測定
し、各々の変位量とジャッキの圧力と面積から算出した
杭に作用している荷重から、杭の支持力が評価されるこ
とになる。Therefore, the displacement of the pressing surface of the jack and the displacement of the pile head are measured individually, and the supporting force of the pile is evaluated from the load acting on the pile calculated from the displacement amount of each, the pressure of the jack and the area. .
この時、杭の周面摩擦力が極限に達した場合には、摩
擦力増加用突起を杭の側面より外方に突出させて、周面
摩擦力を増大させ、杭の下端が極限支持力に達するまで
載荷させればよい。At this time, if the peripheral frictional force of the pile reaches the limit, the protrusion for increasing the frictional force is projected outward from the side surface of the pile to increase the peripheral frictional force, and the lower end of the pile has the ultimate bearing force. Just load until you reach.
又、先端閉塞杭から先端開放杭により、杭の先端にそ
れぞれ先端閉塞板か先端シュー等が取付けられることに
なる。又、載荷試験が終了した場合には、受圧板等を取
外した後、少なくとも載荷用のジャッキは回収され、再
利用されることになる。Further, the tip closing plate or the tip shoe is attached to the tip of the pile from the tip closing pile to the tip opening pile. Further, when the loading test is completed, after removing the pressure receiving plate and the like, at least the loading jack is collected and reused.
［実施例］ 以下、本発明を図面に示す実施例に基づいて具体的に
説明する。[Examples] Hereinafter, the present invention will be specifically described based on Examples shown in the drawings.
第１図は本発明の１実施例を示す、杭の先端を閉塞し
て打設する杭の載荷試験装置の断面図で、第２図はその
平面図、第３図はその杭の地上部の断面図、又第４図は
その杭の下端部の断面図である。FIG. 1 is a sectional view of a pile loading test apparatus for placing a pile by closing the tip of the pile according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a ground portion of the pile. FIG. 4 is a sectional view of the lower end portion of the pile.
図中１は所定深度に沈設された中空の杭で、その下端
には先端支持力を受ける先端閉塞板２がシール2aを介し
て取付けられている。３はその中空の杭１内に挿入され
た送圧管で、送圧管３の下端には、底面を押圧面とする
押込み用のジャッキ４が、シリンダー５を介して取付け
られ、シリンダー５は送圧管３の下端に螺着され、着脱
自在に固定されている。又、送圧管３の上端には、上面
を受圧面とする載荷用のジャッキ６が、シリンダー７を
介して取付けられ、シリンダー７は送圧管３の上端に螺
着され、着脱自在に固定されている。In the figure, reference numeral 1 denotes a hollow pile which is sunk to a predetermined depth, and a tip closing plate 2 which receives a tip supporting force is attached to the lower end of the pile through a seal 2a. Reference numeral 3 denotes a pressure feeding pipe inserted into the hollow pile 1. At the lower end of the pressure feeding pipe 3, a pushing jack 4 having a bottom surface as a pressing surface is attached via a cylinder 5, and the cylinder 5 is a pressure feeding pipe. It is screwed to the lower end of 3 and is detachably fixed. A loading jack 6 having an upper surface as a pressure receiving surface is attached to the upper end of the pressure feeding pipe 3 via a cylinder 7. The cylinder 7 is screwed to the upper end of the pressure feeding pipe 3 and is detachably fixed. There is.
なお、８は押込み用のジャッキ４とシリンダー５、及
び載荷用のジャッキ６とシリンダー７との摺動部を水密
に保つためのパッキンである。Reference numeral 8 is a packing for keeping the sliding portions of the pushing jack 4 and the cylinder 5 and the loading jack 6 and the cylinder 7 watertight.
次に、９は杭１の上端に溶接により固定された内リン
グで、その外周には外リング10が螺着されている。11は
その外リング10の上端に円周方向に等間隔をおいて垂直
に４ケ所螺着して立設された引抜き棒である。12は引抜
き棒11に挿通されて、載荷用のジャッキ６上に載置され
た受圧板で、受圧板12の上面より突出する引抜き棒11
の、上端ねじ部に螺着されたナット13を締付けることに
より、載荷用のジャッキ６の上面は、杭１の上端に引抜
き棒11を介して着脱自在に固定された受圧板12に当接さ
れるようになっている。Next, 9 is an inner ring fixed to the upper end of the pile 1 by welding, and an outer ring 10 is screwed on the outer periphery thereof. Reference numeral 11 denotes a pull-out rod which is vertically installed on the upper end of the outer ring 10 at equal intervals in the circumferential direction and vertically screwed to four places. Reference numeral 12 is a pressure receiving plate which is inserted into the pulling rod 11 and is placed on the jack 6 for loading, and the pulling rod 11 protruding from the upper surface of the pressure receiving plate 12
By tightening the nut 13 screwed to the upper end screw portion, the upper surface of the loading jack 6 is brought into contact with the pressure receiving plate 12 which is detachably fixed to the upper end of the pile 1 via the pulling rod 11. It has become so.
次に、14は鋼線又は鋼棒で、その下端は押込み用のジ
ャッキ４の中空部内底に固着されている。15はフック棒
で、受圧板12の中央部に設けられた穴16を介して、載荷
用のジャッキ６の受圧面の中央を貫通して螺着され、そ
の下端には鋼線又は鋼棒14の上端が係止されている。な
お、17はフック棒15が載荷用のジャッキ６を貫通する部
分に設けられた水密用のパッキンである。次に、18は加
圧用のポンプで、ポンプ18により加圧された圧力水は、
供給管19を介して載荷用のジャッキ６内に供給され、送
圧管３を介して押込み用のジャッキ４内にも供給される
ようになっており、供給管19の途中には、供給される圧
力水の圧力を調節するための調圧弁20と、圧力水の圧力
を表示する圧力計21が取付けられている。なお、22は排
圧管で、その一端は載荷用のジャッキ６内に接続され、
その途中にはバルブ23が設けられている。Next, 14 is a steel wire or steel rod, the lower end of which is fixed to the inner bottom of the hollow portion of the jack 4 for pushing. Reference numeral 15 is a hook rod, which is screwed through the center of the pressure receiving surface of the loading jack 6 through a hole 16 provided in the central portion of the pressure receiving plate 12, and has a steel wire or steel rod 14 at its lower end. The upper end of is locked. Reference numeral 17 is a watertight packing provided in a portion where the hook bar 15 penetrates the loading jack 6. Next, 18 is a pump for pressurization, the pressure water pressurized by the pump 18 is
It is supplied through the supply pipe 19 into the loading jack 6 and also through the pressure-feeding pipe 3 into the pushing jack 4 and is supplied in the middle of the supply pipe 19. A pressure adjusting valve 20 for adjusting the pressure of the pressure water and a pressure gauge 21 for displaying the pressure of the pressure water are attached. In addition, 22 is an exhaust pipe, one end of which is connected to the jack 6 for loading,
A valve 23 is provided on the way.
次に、24は杭１の側壁に設けられた加圧室25内に収容
されて、杭１の側面より外方に突出可能な、摩擦力増加
用突起で、各加圧室25は連通穴26を介して相互に連通さ
れている。27は杭１の側壁内に設けられた垂直穴で、そ
の下端は加圧室25と連通されている。28は加圧室25内に
圧力水を供給するためのポンプで、供給管29を介して垂
直穴27の上端と接続されており、供給管29の途中には調
圧弁30が設けられている。Next, 24 is a projection for increasing the frictional force, which is housed in a pressurizing chamber 25 provided on the side wall of the pile 1 and can project outward from the side surface of the pile 1, and each pressurizing chamber 25 has a communication hole. They are in communication with each other via 26. Reference numeral 27 is a vertical hole provided in the side wall of the pile 1, the lower end of which is in communication with the pressurizing chamber 25. 28 is a pump for supplying pressurized water into the pressurizing chamber 25, which is connected to the upper end of the vertical hole 27 via a supply pipe 29, and a pressure regulating valve 30 is provided in the middle of the supply pipe 29. .
次に、31はフック棒15に設けられた水平なアーム32に
当接して、フック棒15の変位を測定するダイヤルゲージ
で、33は杭１の上部に設けられた水平なフランジ34に当
接して、杭１の変位を測定するダイヤルゲージである。Next, 31 is a dial gauge that abuts on a horizontal arm 32 provided on the hook rod 15 to measure the displacement of the hook rod 15, and 33 abuts on a horizontal flange 34 provided on the upper portion of the pile 1. A dial gauge for measuring the displacement of the pile 1.
従って、押込み用のジャッキ４の押圧面及び杭頭の変
位は、ダイヤルゲージ31及び33の変位量より個別に求め
られることになる。Therefore, the displacement of the pressing surface of the pushing jack 4 and the pile head can be individually calculated from the displacement amounts of the dial gauges 31 and 33.
上記のように構成された本実施例の装置を用いて、杭
先端を閉塞して打設する杭の載荷試験を行うには、杭１
の先端に先端閉塞板２を取付けて、杭１を所定深度に沈
設する。次に、下端に押込み用ジャッキ４を有し、上端
に載荷用のジャッキ６を有する送圧管３を、沈設された
杭１内に挿入する。次に、杭１の上端部に引抜き棒11を
立設して、受圧板12を載荷用のジャッキ６の上面に載置
し、ナット13を締付けて固定する。In order to perform a load test of a pile in which the tip of the pile is closed and placed using the apparatus of the present embodiment configured as described above, the pile 1
The tip closing plate 2 is attached to the tip of, and the pile 1 is sunk to a predetermined depth. Next, the pressure feeding pipe 3 having the pushing jack 4 at the lower end and the loading jack 6 at the upper end is inserted into the sunk pile 1. Next, the extraction rod 11 is erected on the upper end of the pile 1, the pressure receiving plate 12 is placed on the upper surface of the jack 6 for loading, and the nut 13 is tightened and fixed.
次に、バルブ23を開にしてポンプ18を駆動し、圧力水
を供給する。圧力水が排圧管29から排出され、送圧管３
や押込み用ジャッキ４、載荷用のジャッキ６内等にあっ
た空気が完全にパージされたのを確認した後、バルブ23
を閉にして加圧を開始し、載荷試験を行う。杭１の支持
力は、圧力計21の指示圧、すなわち、ジャッキ４の圧力
と断面積を乗じて算出される荷重と、ダイヤルゲージ31
及び33により測定される変位の関係から、従来と同様に
して評価されることになる。Next, the valve 23 is opened and the pump 18 is driven to supply pressurized water. Pressure water is discharged from the exhaust pipe 29, and the pressure pipe 3
After confirming that the air in the jacks 4 for pushing, the jacks 6 for loading, etc. has been completely purged, the valve 23
Close and start pressurization, and carry out a load test. The bearing force of the pile 1 is the pressure indicated by the pressure gauge 21, that is, the load calculated by multiplying the pressure of the jack 4 by the cross-sectional area, and the dial gauge 31.
From the relationship between the displacements measured by 33 and 33, the evaluation will be performed in the same manner as in the past.
但し、載荷試験時に、杭１に作用する周面摩擦力が、
先端閉塞板２を介して押込み用のジャッキ４に作用する
地盤の支持力に先行して極限に達した場合には、ポンプ
28により加圧室25に圧力水を供給して、摩擦力増加用突
起24を杭１の側面より外方に突出せしめ、周面摩擦力を
増大させた状態で、杭先端地盤が極限荷重に達するまで
載荷試験を行えばよい。However, during the load test, the peripheral frictional force acting on the pile 1 is
When the ground support force acting on the pushing jack 4 through the tip closing plate 2 is reached to the limit, the pump
The pressure water is supplied to the pressurizing chamber 25 by the 28, and the projection 24 for increasing the frictional force is projected outward from the side surface of the pile 1 to increase the circumferential frictional force, and the pile tip ground is subjected to the ultimate load. It is sufficient to carry out a load test until it reaches.
なお、載荷試験を終えたならば、杭１の上端部より受
圧板12を取外し、送圧管３と押込み用のジャッキを引き
上げて、杭１の中にコンクリートを打設すればよい。After the loading test is completed, the pressure receiving plate 12 may be removed from the upper end of the pile 1, the pressure feeding pipe 3 and the jack for pushing may be pulled up, and concrete may be placed in the pile 1.
なお、第４図（Ａ）は先端閉塞板の１実施例を示す断
面図である。Incidentally, FIG. 4 (A) is a sectional view showing one embodiment of the tip closing plate.
杭１先端の閉塞板２は杭１先端の根固めの状態や杭１
の打設方法に応じて形状を変えることができる。第４図
（Ａ）は、その１実施例である。例えば埋込み杭先端の
根固め部を先端閉塞板２の上下で縁切りするため、プラ
スチック、金属板等よりなる縁切り材2bを取付具2cを介
して取り付ける。縁切り材2bの長さは、杭１と周辺地盤
間にある根固めのセメントミルクの厚さに応じて変える
ことができる。The blocking plate 2 at the tip of the pile 1 is used to fix the pile 1 at the tip and the pile 1
The shape can be changed according to the driving method. FIG. 4 (A) shows one example thereof. For example, in order to cut the rooted portion at the tip of the embedded pile at the top and bottom of the tip closing plate 2, an edge cutting material 2b made of plastic, metal plate or the like is attached via the attachment tool 2c. The length of the edging material 2b can be changed according to the thickness of the cement milk for consolidation between the pile 1 and the surrounding ground.
次に、第５図及び第６図は、本発明の他実施例を示
す、杭の先端を開放して打設する杭の載荷試験装置の、
それぞれ異なる方式による杭の下端部の断面図である。Next, FIG. 5 and FIG. 6 show another embodiment of the present invention, which is a pile loading test apparatus for driving the pile by opening the tip of the pile.
It is sectional drawing of the lower end part of the pile by each different system.
第５図に示す実施例は、杭先端を開放して打設する杭
１の中空部には、土砂が入って来るので、この土砂をボ
ーリングにより掘削除去した後、底部に平滑剤35を敷
き、その次に送圧管３を杭１内に挿入して、第１図〜第
４図に示す実施例と同様に、載荷試験を行うようにした
もので、送圧管３の下端にある押込み用のジャッキ４部
分の構造は、第４図に示すものと同様であるため、同一
部材には同一符号を付し、各部の説明は省略する。In the embodiment shown in FIG. 5, since earth and sand enter the hollow part of the pile 1 which is driven with the tip of the pile open, the earth and sand are excavated and removed by boring, and then the smoothing agent 35 is spread on the bottom. Then, the pressure-feeding pipe 3 is inserted into the pile 1 to carry out a load test similarly to the embodiment shown in FIGS. 1 to 4, and is for pushing at the lower end of the pressure-feeding pipe 3. Since the structure of the jack 4 part is the same as that shown in FIG. 4, the same members are designated by the same reference numerals and the description of each part is omitted.
又、第６図に示す実施例は、送圧管３の下端に、押込
み用のジャッキ４をシリンダー５を介して取付ける代り
に、送圧管３の下端に押込み用ジャッキ４′を直接取付
けて、押込み用ジャッキ４′が送圧管３と一体的に移動
し得るようにし、送圧管３と共に押込み用のジャッキ
４′が、杭１の底部に敷かれた平滑剤35を介して、地盤
の支持力を受けるようにしたもので、送圧管３の上端に
は、第３図に示すように、載荷用のジャッキ６がシリン
ダー８を介して取付けられているため、送圧管３内を加
圧すると、押込み用ジャッキ４′の底面の押圧面が下方
に変位し、第５図に示す実施例と同様に、載荷試験を行
うことができる。Further, in the embodiment shown in FIG. 6, instead of attaching the pushing jack 4 to the lower end of the pressure feeding pipe 3 via the cylinder 5, the pushing jack 4'is directly attached to the lower end of the pressure feeding pipe 3 to push it in. The jack 4 ′ for movement can be moved integrally with the pressure-feeding pipe 3, and the jack 4 ′ for pushing together with the pressure-feeding pipe 3 increases the supporting force of the ground through the smoothing agent 35 laid on the bottom of the pile 1. As shown in FIG. 3, a jack 6 for loading is attached to the upper end of the pressure-feeding pipe 3 via a cylinder 8. The pressing surface of the bottom surface of the jack 4'is displaced downward, so that the loading test can be performed as in the embodiment shown in FIG.
次に、第７図は本発明のさらに他の実施例を示す、杭
径が大きい場合の、杭先端を開放して打設する杭の載荷
試験装置の杭の下端部の断面図である。Next, FIG. 7 is a cross-sectional view of a lower end portion of a pile loading test apparatus for placing a pile with the tip of the pile open, when a pile diameter is large, showing still another embodiment of the present invention.
本実施例で示すように、杭１の打設によって、杭１の
先端部より侵入した土砂36をボーリング等により堀削除
去する際、杭先端地盤が攪乱される恐れがある。従っ
て、この場合は、杭１の下端に図示のような先端シュー
37をシール37aを介して取付けて、その先端シュー37の
天井周面38より少し下までボーリング等で堀削除去した
後その天井周面38で、押込み用のジャッキ４の底面の押
圧面を受けさせて載荷すれば杭先端部の攪乱を最小限に
押えて載荷試験を行うことができる。なお、本実施例に
おける送圧管３の下部の構造は、第５図に示すものと同
様であるため、同一部材には同一符号を付し、重複した
説明は省略する。As shown in the present embodiment, when the pile 1 is cast, the soil at the tip of the pile 1 may be disturbed when the soil 36 that has entered from the tip of the pile 1 is removed by boring or the like. Therefore, in this case, the tip shoe as shown is attached to the lower end of the pile 1.
37 is attached via the seal 37a, and the tip shoe 37 is dug up to a little below the ceiling peripheral surface 38 by boring or the like, and then the ceiling peripheral surface 38 receives the pressing surface of the bottom surface of the jack 4 for pushing. Then, the loading test can be performed with the disturbance at the tip of the pile suppressed to a minimum. Since the structure of the lower part of the pressure feeding pipe 3 in this embodiment is the same as that shown in FIG. 5, the same members are designated by the same reference numerals, and the duplicated description will be omitted.
但し、第５図，第６図，第７図に示す実施例のものに
おいても、第１図に示すように、杭１の側面に、外方に
突出する摩擦力増加用突起24を設けてもよい。However, also in the embodiment shown in FIGS. 5, 6, and 7, as shown in FIG. 1, a protrusion 24 for increasing the frictional force is provided on the side surface of the pile 1 so as to project outward. Good.
次に第８図は本発明のさらに他の実施例を示す補強し
た杭の載荷試験装置の断面図で、図中第１図に示す部材
と同一部材には同一符号を付し、重複した説明は省略す
る。Next, FIG. 8 is a cross-sectional view of a reinforced pile loading test apparatus showing still another embodiment of the present invention. The same members as those shown in FIG. Is omitted.
杭材の強度が引抜き力より小さい場合には、杭頭に引
抜きを作用させると杭材が破損される恐れがあるので、
杭頭から杭先端まで、鉄筋等の補強材39を入れて、これ
に引抜き力を与えるようにすればよい。但し、図中40は
杭１の下端に取付けた端板を示す。If the strength of the pile material is less than the pulling force, pulling the pile head may damage the pile material.
A reinforcing material 39 such as a reinforcing bar may be inserted from the pile head to the tip of the pile to apply a pulling force to this. However, reference numeral 40 in the figure denotes an end plate attached to the lower end of the pile 1.
なお、本装置による載荷試験の要領は、第１図に示す
ものと同じであるため、説明は省略する。又、本発明は
上記各実施例に限定されるものでなく、両ジャッキ４及
び６の構造や、加圧方法、両ジャッキの押圧面の変位の
測定手段等は、任意に設計変更可能である。Since the procedure of the loading test by this device is the same as that shown in FIG. 1, the description is omitted. Further, the present invention is not limited to the above-mentioned respective embodiments, and the design of the structures of both jacks 4 and 6, the pressing method, the means for measuring the displacement of the pressing surfaces of both jacks, etc. can be arbitrarily changed. .
［発明の効果］ 以上具体的に説明したように、本発明によれば、杭を
所定深度に沈設し、その杭内に、下端に押込み用ジャッ
キを有すると共に、上端に載荷用のジャッキを有する送
圧管を挿入し、載荷用のジャッキの受圧面を、杭の上端
に着脱自在に固定された受圧板に当接させて、送圧管を
介し、両ジャッキに圧力を加えると、ジャッキによる載
荷重は、杭の周面においては周辺土との周面摩擦により
支持され、杭の下端においては先端地盤の支持力により
支持されるので、押圧面及び杭頭の変位を個別に測定
し、各々の変位量と、ジャッキの圧力と面積から算出し
た杭に作用している荷重から、杭の支持力を評価するこ
とができ、従来のように反力杭や連結梁を用いる必要は
なく、試験用の杭のみで簡単に支持力を評価することが
できる。[Effects of the Invention] As specifically described above, according to the present invention, a pile is sunk to a predetermined depth, and a pushing jack is provided at the lower end and a loading jack is provided at the upper end in the pile. Insert the pressure-feeding pipe, bring the pressure-receiving surface of the loading jack into contact with the pressure-receiving plate that is detachably fixed to the upper end of the pile, and apply pressure to both jacks via the pressure-feeding pipe. Is supported by peripheral friction with the surrounding soil on the peripheral surface of the pile and supported by the supporting force of the tip ground at the lower end of the pile, so the displacements of the pressing surface and the pile head are measured individually, and It is possible to evaluate the bearing capacity of the pile based on the amount of displacement and the load acting on the pile calculated from the jack pressure and area. You can easily evaluate the bearing capacity with only the pile of .
又、載荷用のジャッキは、送圧管の上端に着脱自在に
取付けられているため、載荷試験終了後、受圧板を取外
せば、ジャッキを回収することができそれを再利用でき
るので、きわめて経済的である。Also, since the loading jack is detachably attached to the upper end of the pressure feeding pipe, the jack can be collected and reused by removing the pressure receiving plate after the loading test is completed, which is extremely economical. Target.
又、両ジャッキは共通の送圧管を介して、同一の圧力
水により加圧されるので、加圧手段が簡単となり、構造
がコンパクトになる。又、摩擦力増加用突起を突出させ
れば杭の周面摩擦を増大させることができると共に、杭
の先端に先端閉塞板や先端シューを着脱するだけで、先
端閉塞杭や先端開放杭に適用することができ、場合によ
っては押込み用のジャッキを送圧管と一体的に移動し得
るように取付けることも可能で、適用範囲がきわめて広
い。等多くの利点を有し、実用上きわめて有効な、杭の
載荷試験方法及びその装置を提供し得るものである。Further, since both jacks are pressurized by the same pressure water through the common pressure-feeding pipe, the pressurizing means becomes simple and the structure becomes compact. Also, if the projections for increasing the frictional force are projected, the peripheral friction of the pile can be increased, and it can be applied to the tip closed pile or the open tip pile by simply attaching and detaching the tip closing plate and the tip shoe to the tip of the pile. The jack for pushing can be attached so as to be able to move integrally with the pressure feeding pipe in some cases, and the application range is extremely wide. It is possible to provide a pile loading test method and its apparatus that have many advantages and are extremely effective in practice.
第１図は本発明の１実施例を示す、杭の先端を閉塞して
打設する杭の載荷試験装置の断面図で、第２図はその平
面図、第３図はその杭の地上部の断面図、第４図はその
杭の下端部の断面図、第４図（Ａ）は先端閉塞位置の１
実施例を示す断面図、第５図及び第６図は、他の実施例
を示す、杭の先端を開放して打設する杭の載荷試験装置
の、それぞれ異なる方式による杭の下端部の断面図、第
７図は本発明のさらに他の実施例を示す、杭先端を開放
して打設する杭の載荷試験装置の、杭の下端部の断面
図、第８図は本発明のさらに他の実施例を示す補強した
杭の載荷試験装置の断面図、第９図は従来の杭の載荷試
験装置の側面図で、第10図はその平面図である。 １……杭、２……先端閉塞板、2a……シール、2b……縁
切り材、2c……取付具、３……送圧管、4,4′……押込
み用のジャッキ、５……シリンダー、６……載荷用のジ
ャッキ、７……シリンダー、８……パッキン、９……内
リング、10……外リング、11……引抜き棒、12……受圧
板、13……ナット、14……鋼線又は鋼棒、15……フック
棒、16……穴、17……パッキン、18……ポンプ、19……
供給管、20……調圧弁、21……圧力計、22……排圧管、
23……バルブ、24……摩擦力増加用突起、25……加圧
室、26……連通穴、27……垂直穴、28……ポンプ、29…
…供給管、30……調圧弁、31……ダイヤルゲージ、32…
…アーム、33……ダイヤルゲージ、34……フランジ、35
……平滑剤、36……土砂、37……先端シュー、37a……
シール、38……天井周面、39……補強材、40……端板、
101……反力杭、102……連結梁、103……ジャッキ、104
……試験用の杭。FIG. 1 is a sectional view of a pile loading test apparatus for placing a pile by closing the tip of the pile according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a ground portion of the pile. 4 is a sectional view of the lower end portion of the pile, and FIG.
Cross-sectional views showing an embodiment, FIGS. 5 and 6 are cross-sectional views of a lower end portion of a pile according to different methods of a pile loading test apparatus in which the tip of the pile is opened and placed, showing another embodiment. Drawing, Drawing 7 show other examples of the present invention, Sectional drawing of the lower end part of a pile of a pile loading test device which opens and installs the tip of a pile, and Drawing 8 is a further another of the present invention. FIG. 9 is a cross-sectional view of a reinforced pile loading test apparatus showing the above embodiment, FIG. 9 is a side view of a conventional pile loading test apparatus, and FIG. 10 is a plan view thereof. 1 ... Pile, 2 ... Tip closing plate, 2a ... Seal, 2b ... Edge cutting material, 2c ... Mounting fixture, 3 ... Pressure pipe, 4,4 '... Jack for pushing, 5 ... Cylinder , 6 …… loading jack, 7 …… cylinder, 8 …… packing, 9 …… inner ring, 10 …… outer ring, 11 …… drawing rod, 12 …… pressure plate, 13 …… nut, 14… … Steel wire or steel rod, 15 …… hook rod, 16 …… hole, 17 …… packing, 18 …… pump, 19 ……
Supply pipe, 20 …… pressure regulating valve, 21 …… pressure gauge, 22 …… exhaust pressure pipe,
23 ... Valve, 24 ... Protrusion for increasing frictional force, 25 ... Pressurizing chamber, 26 ... Communication hole, 27 ... Vertical hole, 28 ... Pump, 29 ...
… Supply pipe, 30 …… Pressure regulator, 31 …… Dial gauge, 32…
… Arm, 33 …… Dial gauge, 34 …… Flange, 35
…… Smoothing agent, 36 …… Sand, 37 …… Shoe tip, 37a ……
Seal, 38 …… Ceiling surface, 39 …… Reinforcement material, 40 …… End plate,
101 …… reaction force pile, 102 …… connecting beam, 103 …… jack, 104
…… A test stake.
Claims (6)
に底面を押圧面とする押込み用のジャッキを有すると共
に、上端に上面を受圧面とする着脱自在な載荷用のジャ
ッキを有する送圧管を挿入し、その載荷用のジャッキの
上面を、杭の上端に引抜き棒を介して着脱自在に固定さ
れた受圧板に当接せしめた状態で、送圧管を介して両ジ
ャッキに圧力を加えて、ジャッキの押圧面及び杭頭の変
位を個別に測定し、各々の変位量とジャッキの圧力と面
積から算出した杭に作用している荷重から、杭の支持力
を評価することを特徴とする、杭の載荷試験方法。1. A hollow pile sunk to a predetermined depth has a pushing jack having a bottom surface as a pressing surface at a lower end, and a detachable loading jack having an upper surface as a pressure receiving surface at an upper end. Insert the pressure-feeding pipe, apply pressure to both jacks via the pressure-feeding pipe with the upper surface of the loading jack abutting against the pressure-receiving plate that is detachably fixed to the upper end of the pile with the pull-out rod. In addition, the displacement of the pressing surface of the jack and the displacement of the pile head are individually measured, and the supporting force of the pile is evaluated from the load acting on the pile calculated from each displacement amount and the pressure and area of the jack. The load test method for piles.
して着脱自在に固定された受圧板と、その杭内に挿入さ
れる送圧管と、送圧管の下端に取付けられた、底面を押
圧面とする押込み用のジャッキと、送圧管の上端に取付
けられて、受圧板と当接する、上面を受圧面とする着脱
自在な載荷用のジャッキと、送圧管を介し両ジャッキに
圧力を加える加圧手段と、ジャッキの押圧面及び杭頭の
変位を個別に測定する変位測定手段を有することを特徴
とする、杭の載荷試験装置。2. A hollow pile, a pressure receiving plate detachably fixed to the upper end of the pile via a pulling rod, a pressure feed pipe inserted into the pile, and attached to the lower end of the pressure feed pipe. Pressing jack whose bottom surface is the pressing surface, detachable loading jack that is attached to the upper end of the pressure feeding pipe and contacts the pressure receiving plate and whose top surface is the pressure receiving surface, and pressure is applied to both jacks via the pressure feeding pipe. A load testing device for a pile, comprising: a pressurizing means for applying a pressure and a displacement measuring means for individually measuring the displacements of the pressing surface of the jack and the pile head.
用突起が設けられていることを特徴とする、特許請求の
範囲第２項記載の杭の載荷試験装置。3. The pile loading test apparatus according to claim 2, wherein a protrusion for increasing frictional force that can project outward is provided on a side surface of the pile.
ことを特徴とする、特許請求の範囲第２項記載の杭の載
荷試験装置。4. The pile loading test apparatus according to claim 2, wherein a tip closing plate is attached to the tip of the pile.
ていることを特徴とする、特許請求の範囲第２項記載の
杭の載荷試験装置。5. The pile loading test apparatus according to claim 2, wherein a semi-open tip shoe is provided at the tip of the pile.
移動し得るように取付けられていることを特徴とする、
特許請求の範囲第２項記載の杭の載荷試験装置。6. A jack for pushing is attached so as to move integrally with the pressure feeding pipe,
The pile load testing device according to claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62327169A JP2551800B2 (en) | 1987-12-25 | 1987-12-25 | Pile loading test method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62327169A JP2551800B2 (en) | 1987-12-25 | 1987-12-25 | Pile loading test method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01169012A JPH01169012A (en) | 1989-07-04 |
| JP2551800B2 true JP2551800B2 (en) | 1996-11-06 |
Family
ID=18196076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62327169A Expired - Lifetime JP2551800B2 (en) | 1987-12-25 | 1987-12-25 | Pile loading test method and device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2551800B2 (en) |
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| CN102607754A (en) * | 2012-03-16 | 2012-07-25 | 东南大学 | Device for measuring negative skin friction of pile soil |
| CN106149491A (en) * | 2016-08-30 | 2016-11-23 | 中铁第四勘察设计院集团有限公司 | Abutment wall cutting shoe device for jacking construction |
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|---|---|---|---|---|
| JPH03176509A (en) * | 1989-12-05 | 1991-07-31 | Fujita Corp | Load testing method of cast-in-place pile and device thereof |
| JP2012184596A (en) * | 2011-03-07 | 2012-09-27 | Taisei Corp | Pile loading test method |
| CN103603380B (en) * | 2013-11-08 | 2015-09-02 | 国家电网公司 | Measure the ancillary test device of rigidity of gravel pile |
| CN104880264A (en) * | 2015-06-05 | 2015-09-02 | 哈尔滨飞机工业集团有限责任公司 | Dynamometer |
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-
1987
- 1987-12-25 JP JP62327169A patent/JP2551800B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102607754A (en) * | 2012-03-16 | 2012-07-25 | 东南大学 | Device for measuring negative skin friction of pile soil |
| CN102607754B (en) * | 2012-03-16 | 2014-01-15 | 东南大学 | Device for measuring negative skin friction of pile soil |
| CN106149491A (en) * | 2016-08-30 | 2016-11-23 | 中铁第四勘察设计院集团有限公司 | Abutment wall cutting shoe device for jacking construction |
| CN106149491B (en) * | 2016-08-30 | 2018-07-06 | 中铁第四勘察设计院集团有限公司 | For the abutment wall cutting shoe device of jacking construction |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01169012A (en) | 1989-07-04 |
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