DE60016645T2 - Method and device for tensioning a tension member from a plurality of individual elements - Google Patents

Abstract

A process and device for putting under tension a multi-element or -strand (E,1,2,3,4) cable, comprising two or more tensioning devices or jacks (A,B) that are applied to two or more elements (E,1,2,3,4) and successively to the individual elements (E,1,2,3,4). <IMAGE>

Description

The The present invention relates to a method for applying a Tensile stress on cables, which is formed from a bundle of elements are what strands, wires Bars or Ropes can be all in the following as "elements" for the sake of brevity and used to make struts, Tie rods, preload cables, retaining cables, cables for anchoring on the ground or for other uses, all of which are hereafter referred to as "cables" for purposes of brevity be designated, wherein the invention, the tension of the cable elements concerns, independently from the use of the cable.

If a cable is put under tension, it is required to ensure that all its elements are clamped uniformly be to act on all its elements with a multi-part Zugbock, that hooks up and energizes all the elements at the same time, starting from zero or a uniform voltage situation. The stronger that the cable to be energized is the larger and heavier will be a goat that has such capacity and consequently can the space required to be attached to the cable becomes extremely large and moving the buck can be a real problem due to both of its size, as also of his weight. These factors can shape the work restrict because the designer has to pay attention to the space required is to move the trestle to energize the cable.

Therefore means the possibility the cables by acting on their individual elements or uniform groups the same (hereafter together with the term elements designated) with goats or more generally with voltage devices energized a remarkable advance that brings many benefits from both design and as well as from a construction perspective. In fact, these can Bucks or Tension devices are easy to handle, they have reduced Dimensions and geometry another, resulting advantage in carrying out the method is through the possibility provided to install the items individually and temporarily to lock without worrying about it Thinking that they will be stretched uniformly, taking postponing the balancing of the voltage at the time becomes, to which all elements are installed. Nevertheless, it is not easy to energize each item individually while ensuring it will be uniform because, as is well known, various factors including the mutual influence, the elasticity of the structure, the variations of the external loads and weather factors give rise to noticeable, progressive voltage differences under the consecutively tensed elements.

Around Voltage solutions have already been proposed to prevent such differences. which single element blocks include, these solutions on the measurement of the elongation values, which are detected during clamping or based on the application of tensions, which are progressively changed, based on theoretical calculations; allow such solutions However, it only to reduce the voltage differences, not too prevent and in most cases Do not allow the uniformity of the applied force individually monitored becomes.

Another, according to EP 0421862 The proposed solution involves monitoring the first string to be energized by means of a strain gauge which is not part of the voltage block, the "control" string used as a reference for tensioning all subsequent strands, thus ensuring their uniform clamping However, at the end of all tensioning operations, the "control" strand must be released to remove the strain gauge and then placed under the same tension as applied to the last strained strand, whereby there is no instrument verification as to whether such voltage value exists has not changed in the meantime.

Yet another method and apparatus are disclosed in US-A-5,809,710 discloses where two hydraulic presses each with a same Hydraulic pump are connected by a supply line and a return line, in such a way a hydraulically communicating connection between the to maintain two presses at all times. A first press is used to tension a first strand which then passes through anchoring a corresponding wedge, then the second press placed on a second strand and actuated until the piston of the first Press a small distance is moved out when the tension equal to the already introduced in the first strand voltage, consequently indicate that the voltages on both strands are the same are.

Such a solution has some disadvantages that make the method and apparatus very complicated: first, this method requires that the first anchoring wedge be loosened by the movement of the first press to prevent its position being changed relative to the first strand; secondly, the two presses are both deactivated when the second press is moved to another strand, causing the first press must also be reactivated at each cocking and the corresponding wedge is repeatedly loosened and fixed; third, in order not to rely on external observation of the presses, it is necessary to equip them with switches, such as position sensors or induction proximity switches, which automatically control the switching off of the pumps when the corresponding voltage has been reached.

The in the claims 1 and 2 claimed and described hereinafter is essentially characterized in that all the cable forming elements by the operation of at least two single-element tensioning devices under uniform Tension can be set, which independently work from each other and in an orderly sequence to the individual Elements are applied without the need for a fixed Reference element still pretend that strain gauges must be installed and removed, not part of the voltage devices are.

Of Further, there is no need for sensors or switches to provide the tensioning devices, nor wedge retaining means on the spanned elements, and each element is stretched only once, consequently excessive wear of the wedge seats prevented.

The The invention will be described hereinafter with reference to a preferred, non-limiting embodiment the same described with reference to the attached Drawings in which:

I is a plan view of the anchoring of a cable, and II . III . IV and V in the form of a diagram sections XX the I show in the various steps of the method according to the invention.

• – Ein Abstandselement, auch kalibrierte Spannungsplatte, Basis, Nasenring genannt, das, wenn es auf der Kabelverankerung platziert wird, es erlaubt, dass Keile oder Klemmvorrichtungen für die Elemente, welche zu verspannen sind, verriegelt und entriegelt werden;
• – zwei Spannungsvorrichtungen, auch Böcke genannt, welche ausgebildet sind, um jedes individuelle Strangelement einzuhaken und unter Spannung zu setzen, wobei die Spannungsvorrichtungen folglich mit Messsystemen oder -Instrumenten versehen sind, wie erforderlich zum Erfassen der aufgebrachten Spannkraft;

sind notwendigerweise eingerichtet zur Konstruktion der Spannungsanordnung.The following items:

• A spacer, also called a calibrated tension plate, base, nose ring, which, when placed on the cable anchorage, allows wedges or clamps for the elements to be braced to be locked and unlocked;
• Two tensioning devices, also called blocks, which are designed to hook and tension each individual strand element, the tensioning devices consequently being provided with measuring systems or instruments as required for detecting the applied tensioning force;

are necessarily arranged for the construction of the voltage arrangement.

In I is generally shown the head of a cable with twelve strands which are anchored by means of wedges, this representation is only an example and not limiting, the invention is on cables which comprise any number and type of elements (strands, wires, rods, cables), applicable, which are blocked in any way, with either parallel or diverging axes.

• 1. Es wird angenommen, dass die Kabelstränge als in geeigneter Weise an einem nicht dargestellten Ende verankert sind und an dem anderen Ende vorläufig mit einem Verankerungselement T verankert sind, wie gezeigt in 2, wobei die Verankerungskraft, wenngleich unterschiedlich für jedes Element, entsprechend den Installierungserfordernissen bestimmt wird;
• 2. die kalibrierte Spannungsplatte ist an der Verankerung T befestigt (II), um unter Spannung gesetzt zu werden, wobei die kalibrierte Spannungsplatte die Klemmvorrichtungen oder -keile C zurückhält, aber ihnen den minimal ausreichenden Raum belässt, der erforderlich ist zum geeigneten Entriegeln der Elemente E zu dem Zeitpunkt, wenn sie unter Spannung gesetzt werden und dann zum Verriegeln von ihnen, wenn sie durch den Bock freigegeben werden;
• 3. der erste Einzelstrangspannungsbock A wird (II) auf den Strang 1 gezogen und zu dem vorgeschriebenen Wert N1 gespannt;
• 4. der zweite Einzelstrangspannungsbock B wird (II) auf den Strang 2 gezogen und gespannt, bis der Spannungswert N2, gezeigt durch den Bock B, der gleiche ist wie der neue Wert N1', gezeigt durch den Bock A. Durch die Konstruktion wird sich N2=N1' ergeben, das ist die gleiche Spannung in beiden der gespannten Stränge;
• 5. Strang 2 wird an der Verankerung geklemmt (III), Bock B wird auf Strang 3 gezogen und unter Spannung gesetzt, bis der Spannungswert N3, gezeigt bei Bock B, der gleiche ist wie der neue Wert N2'; durch die Konstruktion ist N3=N2', das ist die gleiche Spannung in allen gespannten Strängen;
• 6. Strang 1 wird auf die Verankerung geklemmt (IV), Bock A wird auf Strang 4 gezogen und unter Spannung gesetzt, bis der Spannungswert N4, gezeigt durch Bock A, der gleiche ist wie der neue Wert N3', der in den Strängen 1, 2 und 3 vorhanden ist, wie gezeigt bei Bock B. Aus der Konstruktion wird sich N4=N3' ergeben, das ist die gleiche Spannung in allen vier gespannten Strängen.

Referring now to the II . III . IV and on the fundamental four elements, denoted E, comprising strands 1 . 2 . 3 . 4 the uniform voltage operation can be carried out in the following way:

• 1. It is assumed that the cable strands are anchored as suitably at an end, not shown, and anchored at the other end preliminarily with an anchoring element T, as shown in FIG 2 wherein the anchoring force, although different for each element, is determined according to the installation requirements;
• 2. the calibrated tension plate is attached to the anchorage T ( II ) to be placed under tension, the calibrated tension plate retaining the clamps or wedges C, but leaving them the minimum sufficient space required for properly unlocking the elements E at the time they are put under tension and then to lock them when released by the buck;
• 3. the first single-phase voltage block A is ( II ) on the strand 1 pulled and stretched to the prescribed value N1;
• 4. the second single-phase voltage block B is ( II ) on the strand 2 pulled and tensed until the voltage value N2, shown by the block B, is the same as the new value N1 ', shown by the block A. The construction will give N2 = N1', which is the same voltage in both of the strained strands;
• 5th strand 2 is clamped to the anchorage ( III ), Bock B is going on skein 3 pulled and energized until the voltage value N3 shown at Bock B is the same as the new value N2 '; by construction, N3 = N2 ', which is the same stress in all tensioned strands;
• 6th strand 1 is clamped on the anchorage ( IV ), Bock A is on strand 4 pulled and energized until the voltage value N4, shown by block A, is the same as the new value N3 'in the strings 1 . 2 and 3 is present, as shown in Bock B. The construction will result in N4 = N3 ', which is the same stress in all four tensioned strands.

This process can be done in the same way continue to be performed until all the cable forming elements are energized, thus ensuring their ultimately uniform voltage to the same value.

Each element ( 1 . 2 . 3 . 4 ) can be composed of various individual elements.

Out In the example described above, it should be apparent that the two voltage blocks A and B are interchangeable and none of them is a preferred item for applying the voltage. On the contrary, the interchangeability a new, special property which the present invention characterized as it allows, regardless of an element to a to pass on to others and also to return to an element which was previously energized, therefore also allowing that the dimensions of the voltage devices take this into account accomplished become.

In the very rare case where the elements forming the cables are so few that in each case one tension device is always adjacent to the other, it will, if this be a hindrance to them, to be temporarily installed, still be possible to perform the entire, previously described operation by between the plate P and the two Jacks A and B two equal inclined elements D ( V ), hereafter referred to as deflectors, which, by slightly non-uniform biasing of the traction axes of the elements to be energized, would allow to solve possible crossover problems. The invention would still be applicable if the bias voltage is achieved by properly shaping or making the calibrated voltage plate.

• 1. die Möglichkeit, das Abstandselement P mit einer anderen mechanischen Lösung zu montieren als derjenigen, welche in II gezeigt ist, zum Beispiel, aber ohne Limitation, mit Distanzscheiben oder Schraubsystemen;
• 2. die Möglichkeit, das Abstandselement P, in dem die Verriegelungsvorrichtungen C für die Elemente, die unter Spannung zu setzen sind, eingekapselt sind, durch eine Zugbasis (eine für jede Spannungsvorrichtung) zu ersetzen, wobei die Zugbasis geschlossen ist oder Seitenfenster aufweist, welche einen oder eine Gruppe derselben gleichzeitig einschließt und die, wenn erforderlich, mit einem Ablenker D gekoppelt werden können. Diese Lösung ist insbesondere nützlich für automatisches, halbautomatisches oder manuelles Festziehen der Verriegelungsmutter eines schraubbasierten Systems; oder mit der Hilfe des Ablenkers um Überschneidungsprobleme, welche durch die Abmessungen der Jacks verursacht sind, zu überwinden;
• 3. die Möglichkeit, die Zugspannungsbasis oder Distanz P mit einer Keilvorrichtung zu koppeln, welche insbesondere nützlich ist mit den Keilverriegelungssystemen;
• 4. die Möglichkeit, die Zugspannungsbasis direkt auf die Verankerung T zu lehnen oder durch Einkapseln der Verankerung auf einer unterschiedlichen Stützoberfläche;
• 5. die Möglichkeit, zur gleichen Zeit weitere Spannungsvorrichtungen seitlich von beiden Vorrichtungen A und B, die zwingend notwendig sind, zu verwenden;
• 6. die Möglichkeit, verschiedene Spannungsvorrichtungen A und B als hydraulische Böcke zu verwenden, wie mechanische Vorrichtungen, dynamometrische Winden oder andere Vorrichtungen, welche geeignet sind, um die Spannung aufzubringen;
• 7. die Möglichkeit, den Wert der Kraft, die auf die Elemente aufgebracht wird, durch geeignete Messinstrumente zu messen, die auf die Spannungsvorrichtungen A und B, die Abstandselemente P (Spannungsbasis, Nase oder kalibrierte Platte), auf ihre Stützen oder kalibrierte Platte), auf ihre Stützen oder Ablenker D aufgebracht werden oder mit diesen verbunden werden;
• 8. die Möglichkeit, eine Vorrichtung zu installieren, die automatisch den Spannvorgang des zweiten Bocks B stoppt, wenn der gleiche Wert erreicht wird, der durch den ersten Bock A aufgebracht wird;
• 9. die Verwendung der Erfindung zum Ausgleichen der Spannung einer Kabelanordnung mittels zwei (oder mehr) Mehrelementböcken (diese Böcke haken und spannen gleichzeitig alle diejenigen Elemente, welche das Kabel ausbilden), wobei die individuellen Kabel, die die Anordnung ausbilden, vergleichbar sind mit den individuellen Elementen, welche das Kabel ausbilden. In der Praxis entspricht die Anwendung des Mehrelementbocks bei einer Kabelanordnung einem „höheren Level" des zuvor erwähnten Zustands der Elemente (1, 2, 3, 4), die aus verschiedenen individuellen Elementen zusammengesetzt sind, während der unabhängige Betrieb von jedem Bock unangetastet bleibt.

The application possibilities and variants of the invention and consequently their usage features also include:

• 1. the ability to mount the spacer P with a different mechanical solution than that in II shown, for example, but without limitation, with spacers or screw systems;
• 2. the possibility of replacing the spacer element P in which the locking devices C for the elements to be energized are replaced by a tension base (one for each tension device), wherein the tension base is closed or has side windows which one or a group of them simultaneously and which can be coupled to a deflector D if necessary. This solution is particularly useful for automatic, semi-automatic or manual tightening of the locking nut of a screw-based system; or with the help of the deflector to overcome overlap problems caused by the dimensions of the jacks;
• 3. the ability to couple the tension base or distance P with a wedge device which is particularly useful with the wedge locking systems;
• 4. the ability to lean the tension base directly onto the anchor T or by encapsulating the anchor on a different support surface;
• 5. the possibility at the same time to use further tensioning devices laterally from both devices A and B, which are absolutely necessary;
• 6. the possibility of using different tension devices A and B as hydraulic blocks, such as mechanical devices, dynamometric winches or other devices suitable for applying the tension;
• 7. the ability to measure the value of the force applied to the elements by means of suitable measuring instruments, the tension devices A and B, the spacers P (stress base, nose or calibrated plate), their supports or calibrated plate) , be applied to their supports or deflector D or connected to these;
• 8. the ability to install a device that automatically stops the tensioning operation of the second trestle B when the same value is applied by the first trestle A;
• 9. the use of the invention to equalize the tension of a cable assembly by means of two (or more) multi-element beams (these beams hook and at the same time clamp all those elements which form the cable), the individual cables forming the assembly being comparable to those of FIG individual elements that form the cable. In practice, the application of the multi-element block in a cable arrangement corresponds to a "higher level" of the aforementioned state of the elements ( 1 . 2 . 3 . 4 ), which are composed of various individual elements, while the independent operation of each buck remains untouched.

The Invention may be in various practical construction details modified without the scope defined herein by the claims departing.

Claims (15)

A method for applying a tensile chip On a cable, wherein the cable comprises various elements such as cable strands, so as to obtain the same train on the various elements, wherein the drawing operation is performed on the cable forming elements by two elements are simultaneously placed under tension and the tensile stresses in arranged in an orderly order on the various elements, characterized in that at least two tensioning devices are used, which operate independently of each other, so that at any time always at least one of the elements is under tension and so that the second element is tensioned until its tension is equal to the value of reached under tensioned element. Apparatus for carrying out the method according to claim 1, comprising at least two voltage devices (A, B) for applying a voltage which is applied to two elements, such as cable strands, successively to individual elements (A, B). 1 . 2 . 3 . 4 ) in such a manner that the tensioning devices (A, B) can be moved independently of one element to another, characterized in that the device further comprises measuring instruments mounted on or connected to the tensioning devices (A, B) in such In that a first device (A) is mounted on a first element ( 1 ) the voltage application to a prescribed value (N1) on a first element ( 1 ) and the second device (B) applies the voltage application to a second element ( 2 ) to a value (N2) which will be the same as the new value (N1 ') indicated by the first voltage device (A) and that the voltage devices operate independently of each other. Device according to claim 2, characterized in that that it further includes two inclined elements or deflectors (D), which support the tension devices (A, B) in such a way that these have slightly biased their stress application axes. Device according to Claim 2 or 3, characterized that it further comprises: a spacer or a calibrated one Plate (P) placed between the tensioning devices (A, B) is, and parts or locking and unlocking devices (C) for the elements that are put under tension. Device according to claim 4, characterized in that that the spacer or the calibrated plate (P) is shaped is that slightly biased voltage axes of the devices (A, B) are achieved. Device according to claim 4, characterized in that that the spacer (P) is a spacer or a screw-based System includes. Device according to claim 4, characterized in that that it comprises a calibrated plate (P), which is formed is for each individual tension device (A, B) and is suitable to simultaneously encapsulate a locking device (C), or a group of them. Device according to claim 7, characterized in that in that the plate (P) is coupled with a deflection (D) for each tensioning device (A, B). Device according to claim 4, characterized in that in that the spacer (P) is designed to engage with a wedge device to be coupled. Apparatus according to claim 4, characterized in that the spacer (P) directly on an anchorage (T) of the elements ( 1 . 2 . 3 . 4 ) or supported directly on another support surface, thereby encapsulating the anchorage (T). Device according to one or more of claims 4 to 10, characterized in that it comprises measuring instruments for measuring the value of the force acting on the elements ( 1 . 2 . 3 . 4 ), the instruments being applied or connected to the spacers or the calibrated plates (P), or to their support or to the deflectors (D). Device according to one or more of claims 2 to 11, characterized in that it comprises a device which is suitable for the voltage application by the second voltage device (B) stop when reaching the same value as he through the first tensioning device (A) is exerted. Device according to one or more of claims 2 to 12, characterized in that it comprises two or more voltage devices (A, B). Device according to one or more of claims 2 to 13, characterized in that it comprises two or more multi-element tensioning devices comprising, wherein the voltage devices are adapted to simultaneously to put each individual cable of a cable assembly under tension. Device according to one or more of claims 2 to 14, characterized in that the tensioning devices (A, B) are either hydraulic lifters, mechanical devices, torque wrenches or similar devices which are designed to apply tension to the various elements ( 1 . 2 . 3 . 4 ) exercise.