JPH0144485B2 - - Google Patents
Info
- Publication number
- JPH0144485B2 JPH0144485B2 JP17770081A JP17770081A JPH0144485B2 JP H0144485 B2 JPH0144485 B2 JP H0144485B2 JP 17770081 A JP17770081 A JP 17770081A JP 17770081 A JP17770081 A JP 17770081A JP H0144485 B2 JPH0144485 B2 JP H0144485B2
- Authority
- JP
- Japan
- Prior art keywords
- steel material
- hydraulic pressure
- tension
- elongation
- hydraulic
- 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
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 48
- 239000010959 steel Substances 0.000 claims description 48
- 239000000463 material Substances 0.000 claims description 41
- 238000007726 management method Methods 0.000 claims description 11
- 239000011513 prestressed concrete Substances 0.000 claims description 9
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 description 13
- 238000010586 diagram Methods 0.000 description 7
- 230000005856 abnormality Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000004567 concrete Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000036461 convulsion Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Landscapes
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
Description
【発明の詳細な説明】
この発明は、プレストレストコンクリートにお
けるPC鋼材の緊張作業において、プレストレス
が正しく導入されたか否かを管理する緊張管理方
法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tension management method for managing whether or not prestress is correctly introduced in tensioning work of prestressed steel materials in prestressed concrete.
プレストレストコンクリートは合理的な構造で
あるだけに、施行に多くの因子がきわめてデリケ
ートに関連してくる。そのため、その施工にあた
つては、正しくプレストレスが導入されているか
否かを管理する必要がある。この点、従来PC鋼
材を緊張する作業にあたつては、緊張荷重の段階
に従つて荷重と伸びとを人間が測定し、記録し、
グラフ上に手作業でプロツトしながら管理図を作
成し、その図に基づいて管理をしている。このた
め、従来では、測定者の他に記録者が必要であ
り、また管理図の作成という煩雑な内業を要する
上、測定のために緊張作業を何回も中断するため
緊張完了までに長時間要し、しかも緊張完了後の
データ整理が煩雑である等の問題があつた。 Since prestressed concrete has a rational structure, many factors are extremely delicately related to its implementation. Therefore, during construction, it is necessary to manage whether or not prestress is correctly introduced. In this regard, conventionally, when tensioning prestressing steel materials, humans measure and record the load and elongation according to the stages of tension loading.
A control chart is created by manually plotting on a graph, and management is performed based on that chart. For this reason, in the past, a recorder was required in addition to the measurer, the cumbersome work of creating control charts was required, and the tension work was interrupted many times for measurement, which took a long time to complete. There were problems such as it was time-consuming and complicated to organize the data after the tension was completed.
また、PC鋼材の緊張作業にあたつては、その
程度が管理限界を超えていないことを確認し続け
ることが肝要であり、この点において、従来の手
作業による飛び飛びのデータ（荷重と伸び）収集
では、緊張の程度を正確、かつ速やかに把握する
ことが難しく、管理限界との関係を連続的に確認
することができなかつた。しかも、飛び飛びのデ
ータ収集のため、PC鋼材の緊張が一旦管理限界
を超えて再び戻つた場合にその変化を知ることが
できないというおそれもあつた。 In addition, when performing tension work on prestressing steel materials, it is important to continue to confirm that the degree of tension does not exceed control limits. During the collection, it was difficult to accurately and quickly grasp the level of tension, and it was not possible to continuously confirm the relationship with control limits. Moreover, because the data was collected intermittently, there was a risk that if the tension in the prestressing steel material once exceeded the control limit and returned again, it would be impossible to know the change.
この発明は、上記事情に鑑みてなされたもの
で、その目的とするところは、PC鋼材に与える
緊張荷重とPC鋼材の伸びとを自動的に計測して
緊張過程における両者の関係をマイクロコンピユ
ータによつてモニターテレビでグラフとして連続
的に表示し、かつそのモニターテレビの同一画面
上に、PC鋼材の緊張の管理線図を同時に表示す
ることにより、プレストレスが正しく導入された
か否かを容易に判断でき緊張管理の簡易化を図れ
る上、緊張作業を中断せずに連続的に行ない得て
作業を迅速に進めることができ、さらに管理のた
めの人員を減らし省力化が図れ、しかも各データ
の記録を自動的に行なうことができるプレストレ
ストコンクリートにおけるPC鋼材の緊張管理方
法を提供することである。 This invention was made in view of the above circumstances, and its purpose is to automatically measure the tension load applied to the prestressing steel material and the elongation of the prestressed steel material, and to use a microcomputer to determine the relationship between the two during the tensioning process. Therefore, by displaying the graph continuously on a monitor TV and simultaneously displaying the tension control diagram of the prestressing steel material on the same screen of the monitor TV, it is easy to check whether prestress has been introduced correctly or not. It is possible to make decisions and simplify tension management, it is possible to perform tension work continuously without interruption, and the work can proceed quickly. Furthermore, it is possible to save labor by reducing the number of personnel for management, and moreover, it is possible to simplify tension management. The purpose of the present invention is to provide a method for managing the tension of prestressed steel in prestressed concrete in which recording can be performed automatically.
この発明のプレストレストコンクリートにおけ
るPC鋼材の緊張管理方法は、プレストレストコ
ンクリートにおけるPC鋼材を、液圧ジヤツキに
液圧を与えてジヤツキ内のラムを移動させること
により徐々に緊張させる際に、前記ムラの移動量
および前記液圧をそれぞれ連続的に計測してそれ
ら計測値を電気的に出力させ、PC鋼材の伸びと
液圧を座標軸にとつたモニターテレビ画面の座標
平面上に、前記電気的な出力に基づいてPC鋼材
の伸び−液圧の関係をマイクロコンピユータによ
つて逐次連続的にグラフとして表示させ、さら
に、前記モニターテレビの画面における座標平面
上に、マイクロコンピユータによつて予め求めて
おいた管理線図を同時に表示させ、この管理線図
は、PC鋼材の正しい緊張に伴う伸び−液圧の関
係の変化の許容範囲の下限を表す下限線と、その
許容範囲の上限を表す上限線と、PC鋼材の緊張
の到達限界を表す引き止め線とによつて成り、
PC鋼材の緊張に伴つて、PC鋼材の伸び−液圧の
関係のグラフが前記管理線図の許容範囲内にて直
線的に延びることを確認しつつ緊張管理を行うこ
とを特徴としている。 The tension management method for prestressed concrete steel in prestressed concrete according to the present invention involves gradually tensioning the prestressed steel in prestressed concrete by applying hydraulic pressure to a hydraulic jack and moving a ram in the jack. The amount and the liquid pressure are each continuously measured and the measured values are outputted electrically, and the electrical output is displayed on the coordinate plane of the monitor TV screen with the elongation of the PC steel material and the liquid pressure as the coordinate axes. Based on this, the elongation-hydraulic pressure relationship of the prestressed steel material is displayed as a graph one after another by a microcomputer, and furthermore, the control determined in advance by the microcomputer is displayed on the coordinate plane on the screen of the monitor television. A line diagram is displayed at the same time, and this control diagram has a lower limit line representing the lower limit of the permissible range of change in the elongation-hydraulic pressure relationship due to correct tension of the prestressing steel material, an upper limit line representing the upper limit of the permissible range, It consists of a restraining line that indicates the limit of tension of the prestressed steel material,
The method is characterized in that tension management is performed while confirming that the graph of the relationship between elongation of the prestressing steel material and hydraulic pressure extends linearly within the allowable range of the control chart as the prestressing steel material is tensed.
以下、この発明を図面を参照して説明する。第
１図はこの発明に用いる装置を示すものであり、
まずこの装置について述べる。図中１は周知の緊
張用油圧ジヤツキ（液圧ジヤツキ）である。この
ジヤツキ１には、ジヤツキ１内のラム２が移動し
た時その移動量を計測しその計測値を電気的に出
力する変位ポテンシヨメータ３が設けられてい
る。またジヤツキ１の給油口４には、ジヤツキ１
に流入する油圧（液圧）を計測し、その計測値を
電気的に出力する液圧（以下油圧と称する）ポテ
ンシヨメータ５が設けられている。６は油圧ポン
プである。前記２つのポテンシヨメータ３，５は
マイクロコンピユータ７に接続され、またマイク
ロコンピユータ７には、マイクロコンピユータ７
の処理したデータを適宜表示するためのモニター
テレビ８が接続されている。９はグラフイツクプ
リンター（ハードコピー）で、これは前記モニタ
ーテレビ８の画面に表示された画像およびマイク
ロコンピユータ７の処理した内容を適宜記録する
ものである。 The present invention will be explained below with reference to the drawings. FIG. 1 shows the apparatus used in this invention,
First, I will describe this device. In the figure, 1 is a well-known tensioning hydraulic jack (hydraulic jack). This jack 1 is provided with a displacement potentiometer 3 that measures the amount of movement of the ram 2 in the jack 1 and electrically outputs the measured value. In addition, the jack 1 is attached to the fuel filler port 4 of the jack 1.
A hydraulic pressure (hereinafter referred to as hydraulic pressure) potentiometer 5 is provided for measuring the hydraulic pressure (hydraulic pressure) flowing into the hydraulic pressure (hydraulic pressure) and electrically outputting the measured value. 6 is a hydraulic pump. The two potentiometers 3 and 5 are connected to a microcomputer 7, and the microcomputer 7 is connected to a microcomputer 7.
A monitor television 8 is connected to display the processed data as appropriate. Reference numeral 9 denotes a graphic printer (hard copy), which records the images displayed on the screen of the monitor television 8 and the contents processed by the microcomputer 7 as appropriate.
そして、コンクリート端部１０から抜き出され
たPC鋼材（図示せず）を緊張させる場合には、
通常のようにジヤツキ１内に備えたグリツプ（図
示せず）によりPC鋼材の端部を把持して圧油を
給油口４からジヤツキ１内に導入し、ラム２を移
動させ、これによりPC鋼材を引張る。そして、
その際、油圧（緊張荷重）σn、およびPC鋼材の
伸び△ｌを各ポテンシヨメータ３，５で計測しそ
の計測値を電気的なデジタル量として出力させ
る。こうして得られる各出力は、マイクロコンピ
ユーター７に入力されて図形処理され、横軸を伸
びΔl（mm）、縦軸を油圧（液圧）σn（Kg／cm2）とし
たグラフ上に自動的にプロツトされてモニターテ
レビ８の画面に表示される。 When tensioning the PC steel material (not shown) extracted from the concrete end 10,
As usual, grip the end of the PC steel material with a grip (not shown) provided in the jack 1, introduce pressure oil into the jack 1 from the oil supply port 4, move the ram 2, and thereby pull. and,
At this time, the hydraulic pressure (tension load) σ n and the elongation Δl of the PC steel material are measured by the respective potentiometers 3 and 5, and the measured values are output as electrical digital quantities. Each output obtained in this way is input to the microcomputer 7, processed graphically, and automatically displayed on a graph with the horizontal axis as elongation Δl (mm) and the vertical axis as oil pressure (hydraulic pressure) σ n (Kg/cm 2 ). is plotted on the screen of the monitor television 8.
次に、上記構成の装置を用いて実際に緊張管理
する方法を説明する。 Next, a method for actually managing tension using the apparatus configured as described above will be explained.
まず、本緊張を行なう前に試験緊張を行なつて
管理限界等の各種データを求め管理線図を描く。
そこで、その手順を先に述べる。 First, before conducting the actual tension, test tension is performed to obtain various data such as control limits and draw a control diagram.
Therefore, the procedure will be described first.
(1) まず、摩擦係数μ＝０、μ＝0.4の２つの場
合について、PC鋼材の弾性係数をEpとして
各々緊張計算を行ない油圧σn、伸び量Δlを算
出する。(1) First, for the two cases of friction coefficient μ = 0 and μ = 0.4, the tension is calculated using the elastic modulus of the PC steel material as E p to calculate the oil pressure σ n and the amount of elongation Δl.
(2) (1)で求めた値に対応する点を、第２図に示す
ように、モニターテレビ８に表示した伸び−油
圧グラフの上にプロツトし、その２点を通る直
線イを引き、その線イを正しく分割してμ＝−
0.5〜1.0まで表示する。(2) Plot the points corresponding to the values obtained in (1) on the elongation-hydraulic graph displayed on the monitor TV 8, as shown in Figure 2, and draw a straight line A passing through the two points. Correctly divide the line A and μ=-
Display from 0.5 to 1.0.
(3) 前述の緊張の要領で試験緊張を行ない、その
結果を統計的に処理して見かけの摩擦係数μ〓の
上限値および下限値を求める。また、PC鋼材
の見かけの弾性係数E〓pの下限値を同じく統計
的に求める。(3) Perform test tension according to the tension procedure described above, and statistically process the results to determine the upper and lower limits of the apparent friction coefficient μ〓. In addition, the lower limit value of the apparent elastic modulus E〓 p of the PC steel material is similarly determined statistically.
(4) (3)で求めたμ〓の上限値および下限値を、第３
図に示すように、点Ａ，Ｂとしてイ線上に求
め、これらの点と原点Ｏとを結ぶ直線ロ，ハを
それぞれ引く。(4) The upper and lower limits of μ〓 obtained in (3) are
As shown in the figure, points A and B are found on line A, and straight lines B and C connecting these points and origin O are drawn, respectively.
この直線ロは、PC鋼材の正しい緊張に伴う
伸び（Δl）−油圧（σnの関係の変化の許容範囲
の上限を表す上限線であり、また直線ハは、そ
の許容範囲の下限を表す下限線である。 This straight line B is the upper limit line representing the upper limit of the permissible range of change in the relationship between elongation (Δl) and oil pressure (σ n) due to correct tension of the prestressing steel material, and straight line C is the lower limit line representing the lower limit of the permissible range. It is a line.
(5) (1)で計算したμ＝０の時のPC鋼材の伸びを
Δl1とし、(3)で求めたE〓pの下限値をE〓p1とする
と、弾性係数E〓p1の場合のPC鋼材の伸びΔl2は、
Δl2E〓p1＝Δl1Ep＝σn
より Δl2＝Δl1×Ep／E〓p1
となり、これから求まる。従つて、第４図に示
すように、μ＝０を通る水平線（横軸と平行な
線）上にΔl2に対応する点をとり、この点を通
り線イに平行な線ニを引くと、この線ニがE〓p
の下限線つまりE〓p1の場合を示すことになる。(5) If the elongation of the PC steel material when μ=0 calculated in (1) is Δl 1 , and the lower limit of E〓 p found in (3) is E〓 p1 , then if the elastic modulus E〓 p1 The elongation Δl 2 of the PC steel material is Δl 2 E〓 p1 = Δl 1 E p =σ n , so Δl 2 = Δl 1 ×E p /E〓 p1 , and can be found from this. Therefore, as shown in Figure 4, if we take a point corresponding to Δl 2 on the horizontal line (parallel to the horizontal axis) passing through μ=0 and draw a line D parallel to line A through this point, we get , this line is E〓 p
This shows the lower limit of E〓 p1 .
この線ニは引き止め線である。なお、線イは
弾性係数がEpの場合を示すものである。 This line d is a stop line. Note that line A shows the case where the elastic modulus is E p .
以上のようにして第４図に最終的に示すように
管理限界等を表わす管理線図をモニターテレビ８
の画面に表示し、次に本緊張に入るわけである
が、実際PC鋼材を緊張した場合の真の伸び量は、
ポテンシヨメータ３で計測する見かけの伸び量に
ジヤツキ１内でのストランド伸び、緊張くさびの
滑り等による補正を行なつて求める必要があり、
その補正は関数的にマイクロコンピユータ７に入
力しておき、自動的にその補正後の値がモニター
テレビ８に表示できるようにしておく。 As described above, the control line diagram representing the control limits etc. is finally drawn up on the monitor TV 8 as shown in Fig. 4.
is displayed on the screen, and then the actual tension begins, but the true amount of elongation when the PC steel material is actually tensioned is
It is necessary to calculate the amount of elongation measured by the potentiometer 3 by correcting the elongation of the strand in the jack 1, the slippage of the tension wedge, etc.
The correction is input into the microcomputer 7 in a functional manner so that the corrected value can be automatically displayed on the monitor television 8.
そして、本緊張に入る。その場合、まずPC鋼
材の両端にジヤツキ１を装着し、両端を同時に引
つ張つて緊張油圧を50Kg／cm2にする。そして、こ
の点から伸びを自動計測して順次モニターテレビ
８の画面の伸び−油圧グラフ上にプロツトしてい
く。最終緊張油圧Pnの略2/3程度に進行した時点
で、第５図に示すように、グラフ上の実測データ
をそのまま矢印のように平行移動させて実測デー
タをほぼ結ぶ線の延長線が原点を通るようにす
る。 Then the real tension begins. In that case, first attach jacks 1 to both ends of the PC steel material and pull both ends at the same time to set the tension oil pressure to 50 kg/cm 2 . Then, the elongation is automatically measured from this point and sequentially plotted on the elongation-hydraulic graph on the screen of the monitor television 8. When the final tension oil pressure P n reaches approximately 2/3, as shown in Figure 5, the actual measured data on the graph is moved in parallel as shown by the arrow, and an extension line of the line that approximately connects the measured data is drawn. Make it pass through the origin.
そして、第６図に示すようにモニターテレビ８
の画面上に実測して示される伸び−油圧の関係
が、直線性をもち、かつ管理線図に示される管理
限界内にある、ということを画面上で確認しなが
ら（前記２要件を満足していることはプレストレ
スが正しくかけられていることを示している。）、
緊張油圧をさらに加えていき、最終的に引き止め
線ニに到達したところでそれをマイクロコンピユ
ータ７で判断して自動的にブザーを鳴らし、これ
により緊張作業の完了を知らせる。そして、作業
が終つて時点で、モニターテレビ８に表示された
グラフと、計測した伸び−油圧のうち必要なデー
タを整理した緊張管理表とをグラフイツクプリン
タ（ハードコピー）９で記録する。 Then, as shown in FIG.
While checking on the screen that the elongation-hydraulic relationship actually measured and shown on the screen is linear and within the control limits shown on the control chart (if the above two requirements are met), This indicates that the prestress is applied correctly.)
The tensioning hydraulic pressure is further applied, and when the tensioning line N is finally reached, the microcomputer 7 judges this and automatically sounds a buzzer, thereby notifying the completion of tensioning work. When the work is finished, a graphic printer (hard copy) 9 records the graph displayed on the monitor television 8 and a tension management table in which necessary data of the measured elongation-hydraulic pressure is organized.
なお、計測した結果が前記２点を満足しない時
（つまりプレストレスが正しく導入されていない
時）は、それを容易にモニターテレビ８で視覚的
に確認でき、緊張作業の中断、やり直し等の判断
を簡単に決定できる。 Furthermore, if the measured results do not satisfy the above two points (in other words, the prestress has not been introduced correctly), this can be easily confirmed visually on the monitor TV 8, and a decision can be made to suspend or redo the stress work. can be easily determined.
また、上記においては、プレストレストコンク
リートを施工する場合について述べたが、PC鋼
材の交換時等においても同様に適用できることは
勿論である。 Furthermore, although the above description has been made regarding the case of constructing prestressed concrete, it goes without saying that the present invention can also be similarly applied when replacing prestressed steel materials.
以上説明したように、この発明によれば、PC
鋼材に与える緊張荷重と伸びとを自動的に計測し
て緊張過程における両者の関係をマイクロコンピ
ユータによつてモニターテレビにグラフとして連
続的に表示するとともに、管理限界等の管理線図
を同時にモニターテレビに表示するというもので
あるから、プレストレスが正しく導入されている
か否かをモニターテレビの画面上で容易に視覚的
に判断することができ、緊張管理を実に簡単に行
ない得るものであり、また緊張作業を中断せずに
連続的に管理できるため作業を迅速に進めること
ができ、さらに管理作業をするための人員を減ら
し省力化が図れる。 As explained above, according to this invention, the PC
The tension load and elongation applied to the steel material are automatically measured, and the relationship between the two during the tension process is continuously displayed as a graph on the monitor TV using a microcomputer. At the same time, a control line such as control limits is displayed on the monitor TV. Since the prestress is displayed on the screen, it is easy to visually judge whether or not prestress has been properly introduced on the monitor TV screen, making it extremely easy to manage tension. Since tension work can be managed continuously without interruption, work can proceed quickly, and the number of personnel required to perform management work can be reduced, resulting in labor savings.
特に本発明においては、液圧ジヤツキ１のラム
２の移動量及び液圧をそれぞれ連続的に計測して
それらを計測値を電気的に出力する変位ポテンシ
ヨメータ３及び液圧ポテンシヨメータ５を設けて
おき、それらの電気信号に基づいてモニターテレ
ビ８画面の座標平面上に連続的なグラフとして表
示させるようにしているため、PC鋼材の緊張工
程における緊張状態の正常・異常が即座にかつ極
めて正確に判断できる。即ち、PC鋼材の緊張工
程においては一般に、そのPC鋼材の端部を把持
部に固定して行うが、この把持部が特にチヤツク
装置等の挾持タイプである場合、そのPC鋼材に
対する挾持部分がPC鋼材への食い込みその他の
原因などにより多少位置ずれしたりする現象がし
ばしば発生するものであり、このような場合に
は、PC鋼材の実際の伸張量とラム２の移動量と
が異なることになる。即ち、ラム２の移動量に前
記位置ずれによる誤差が含まれてしまい、変位ポ
テンシヨメータ３は実際よりも大きな計測値を出
力することになる。一方、例えばPC鋼材の製造
時やその他の要因によりそのPC鋼材に僅かの断
面欠損があつても、ジヤツキ１のある液圧に対す
るPC鋼材の伸び、つまりラム２の移動量は計算
値よりも大きくなつてしまうことになる。しかる
に、本発明にあつては、PC鋼材の伸びと液圧の
両方を同時に計測しかつ、伸び−液圧の関係を連
続的な一本のグラフとして表示させているため、
上記の如き異常が発生した場合には、そのグラフ
が途中で急に折れ曲がつたり、曲線を描いたりす
ることになり、従つてこのことで、PC鋼材の緊
張工程に異常が発生したことを即座に判断でき
る。しかも本発明ではその異常の種類までもグラ
フの形状から判読できます。例えば、上限線ロ下
限線ハの間を直線状に伸びる、伸び−液圧の関係
を表示する一本の線分が、途中で仮に水平方向に
伸びていつた場合、その位置では液圧はある圧力
で一定であるのにラム２の伸張量だけが増大して
いることになるので、上記したような把持部のス
リツプやPC鋼材の断面欠損等による伸びないし
歪さらには切断などが発生していることを想定す
ることができます。一方、上方へ向つて伸びてゆ
く場合には、液圧が上昇しているのに対してラム
２の移動が僅かないし異常に小さくなつているこ
とになるので、この場合には例えばどこかに異常
な摩擦などが発生していることを想定することが
できる。従つてこれらのことからその異常部分の
早期発見はもちろん、不都合を起こす前の早期に
緊張状態の調整作業さらには停止などを実施する
ことができることになる、といつた作用効果が得
られる。 In particular, in the present invention, a displacement potentiometer 3 and a hydraulic potentiometer 5 are provided which continuously measure the movement amount and hydraulic pressure of the ram 2 of the hydraulic jack 1 and output the measured values electrically. Since these electric signals are displayed as a continuous graph on the coordinate plane of eight monitor TV screens, the normal and abnormal tension conditions during the tensioning process of prestressing steel materials can be immediately and extremely detected. Can judge accurately. In other words, the tensioning process for prestressed steel is generally carried out by fixing the end of the prestressed steel to a gripping part, but if this gripping part is a clamping type such as a chuck device, the clamping part for the prestressed steel is fixed to the gripping part. A phenomenon in which the prestressing steel material is slightly misaligned due to digging into the steel material or other causes often occurs, and in such cases, the actual amount of expansion of the prestressing steel material and the amount of movement of ram 2 will be different. . That is, the amount of movement of the ram 2 includes an error due to the positional deviation, and the displacement potentiometer 3 outputs a larger measured value than the actual value. On the other hand, even if there is a slight cross-sectional defect in the prestressed steel material due to the manufacturing process or other factors, the elongation of the prestressed steel material in response to the hydraulic pressure with jerk 1, that is, the amount of movement of ram 2, will be larger than the calculated value. You'll end up getting used to it. However, in the present invention, both the elongation of the prestressing steel material and the hydraulic pressure are measured simultaneously, and the relationship between elongation and hydraulic pressure is displayed as one continuous graph.
If an abnormality like the one above occurs, the graph will suddenly bend or draw a curved line, which means that an abnormality has occurred in the tensioning process of the prestressing steel material. can be judged instantly. Moreover, with this invention, even the type of abnormality can be determined from the shape of the graph. For example, if a line segment showing the relationship between elongation and hydraulic pressure that extends linearly between the upper limit line and the lower limit line C extends horizontally in the middle, the hydraulic pressure will be at that position. Even though the pressure is constant, only the amount of extension of the ram 2 is increasing, so there is no elongation, distortion, or even cutting due to slips in the gripping part, cross-sectional defects in the prestressing steel, etc. as mentioned above. You can imagine that there are. On the other hand, when it extends upward, the movement of the ram 2 is small or abnormally small even though the hydraulic pressure is rising, so in this case, for example, somewhere It can be assumed that abnormal friction or the like is occurring. Therefore, from these things, it is possible to not only detect the abnormality at an early stage, but also to adjust the tension state or even stop the system at an early stage before any trouble occurs.
第１図はこの発明の方法を実施するための装置
の概略図、第２図〜第６図はこの発明の方法を説
明するための図である。
１……油圧ジヤツキ、２……ラム、４……変位
ポテンシヨメータ、５……油圧ポテンシヨメー
タ、７……マイクロコンピユータ、８……モニタ
ーテレビ、９……グラフイツクプリンター。
FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention, and FIGS. 2 to 6 are diagrams for explaining the method of the present invention. 1...Hydraulic jack, 2...Ram, 4...Displacement potentiometer, 5...Hydraulic potentiometer, 7...Microcomputer, 8...Monitor TV, 9...Graphics printer.
Claims (1)
材を、液圧ジヤツキに液圧を与えてジヤツキ内の
ラムを移動させることにより徐々に緊張させる際
に、前記液圧ジヤツキに設けた変位ポテンシヨメ
ータおよび液圧ポテンシヨメータによつて、前記
ラムの移動量および前記液圧をそれぞれ連続的に
計測してそれら計測値を電気的に出力させ、PC
鋼材の伸びと液圧を座標軸にとつたモニターテレ
ビ画面の座標平面上に、前記両ポテンシヨメータ
からの電気的な出力に基いてPC鋼材の伸び−液
圧の関係をマイクロコンピユータによつて逐次連
続的に一本のグラフとして表示させ、さらに、前
記モニターテレビの画面における座標平面上に、
マイクロコンピユータによつて予め求めておいた
管理線図を同時に表示させ、この管理線図は、
PC鋼材の正しい緊張に伴う伸び−液圧の関係の
変化の許容範囲の下限を表す下限線と、その許容
範囲の上限を表す上限線と、PC鋼材の緊張の到
達限界を表す引き止め線とによつて成り、PC鋼
材の緊張に伴つて、PC鋼材の伸び−液圧の関係
のグラフが前記管理線図の許容範囲内にて直線的
に延びることを確認しつつ緊張管理を行うことを
特徴とするプレストレストコンクリートにおける
PC鋼材の緊張管理方法。1 When gradually tensioning the PC steel material in prestressed concrete by applying hydraulic pressure to the hydraulic jack and moving the ram in the jack, the displacement potentiometer and hydraulic potentiometer provided in the hydraulic jack The amount of movement of the ram and the hydraulic pressure are each continuously measured, the measured values are output electrically, and the PC
On the coordinate plane of the monitor TV screen with the elongation of the steel material and the hydraulic pressure as the coordinate axes, the relationship between the elongation of the PC steel material and the hydraulic pressure is sequentially plotted by a microcomputer based on the electrical outputs from both potentiometers. Continuously display as a single graph, and further on the coordinate plane on the screen of the monitor television,
A control chart obtained in advance by a microcomputer is displayed at the same time, and this control chart is
A lower limit line representing the lower limit of the permissible range of changes in the elongation-hydraulic pressure relationship due to correct tension of the prestressing steel material, an upper limit line representing the upper limit of that permissible range, and a holding line representing the limit of the tension of the prestressing steel material. Therefore, as the prestressing steel material is tensed, tension management is performed while confirming that the graph of the relationship between elongation of the prestressing steel material and hydraulic pressure extends linearly within the allowable range of the control chart. In prestressed concrete
Tension management method for PC steel materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17770081A JPS5878712A (en) | 1981-11-05 | 1981-11-05 | Method of controlling strain of pc steel material in prestressed concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17770081A JPS5878712A (en) | 1981-11-05 | 1981-11-05 | Method of controlling strain of pc steel material in prestressed concrete |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5878712A JPS5878712A (en) | 1983-05-12 |
| JPH0144485B2 true JPH0144485B2 (en) | 1989-09-28 |
Family
ID=16035569
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17770081A Granted JPS5878712A (en) | 1981-11-05 | 1981-11-05 | Method of controlling strain of pc steel material in prestressed concrete |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5878712A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6121268A (en) * | 1984-07-11 | 1986-01-29 | 鹿島建設株式会社 | Apparatus for tensioning pc steel material |
| JPS6342810A (en) * | 1986-08-08 | 1988-02-24 | 佐藤工業株式会社 | Method of automatically controlling pc steel material stretching force |
| JPH0829545B2 (en) * | 1987-07-10 | 1996-03-27 | 佐藤工業株式会社 | Automatic control method of tension jack for prestressed construction |
| JPS6416606A (en) * | 1987-07-10 | 1989-01-20 | Sato Kogyo | Automatic control device of tension jack for prestressed construction |
| JP2530480B2 (en) * | 1988-05-19 | 1996-09-04 | ツルガスパンクリート株式会社 | Rope tensioning device for use in manufacturing prestressed concrete |
| JP2676126B2 (en) * | 1992-06-15 | 1997-11-12 | 株式会社ジオトップ | Equipment for manufacturing PC concrete pillars, etc. |
| JP5596449B2 (en) * | 2010-07-15 | 2014-09-24 | 三井住友建設株式会社 | Tension introduction device |
| JP6278855B2 (en) * | 2014-07-09 | 2018-02-14 | 鹿島建設株式会社 | Tension management system and tension management method for PC steel |
| KR102317790B1 (en) * | 2020-02-24 | 2021-10-27 | 컨텍이앤씨 주식회사 | Prestressing control method by tendon for prestressed concrete structure |
-
1981
- 1981-11-05 JP JP17770081A patent/JPS5878712A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5878712A (en) | 1983-05-12 |
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