JP2009013605A - Cable fixing member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable fixing member, preventing the teeth of the ridge line part from biting into a stretch material so as not to cause fretting corrosion on an outlet side in the tension direction of the fixing member. <P>SOLUTION: In the fixing member, a stretch material of a stranded wire form penetrates a fixing conical cone, and the stretch material is held by a plurality of split bodies 1. In this cable fixing member, a part of the ridge line part 1a at the outlet side in the tension direction at a circular-arc inner abutting surface of each split body 1 is cut toward the outlet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cable fixing member that tensions and fixes a cable to a fixing portion of a main girder and a main tower, for example, in an oblique cable of a cable-stayed bridge.

Conventionally, as a cable fixing member, as shown in Patent Document 1, a cable fixing member is inserted through a through-hole of a conical cone of an anchor head and fixed through a wedge made up of pieces that are divided into a plurality of wedges. ing.
JP-A-8-74937

  As shown in FIGS. 4 (A) and 4 (B), the conventional cable fixing member wedge 12 is divided into three or two by a conical piece, and a triangular protrusion is formed on the inner wall surface thereof. The teeth are formed. Using this wedge 12, for example, when fixing to a tension material 11 in which a plurality of side wires (for example, a PC steel stranded wire) is twisted around the core wire, as shown in FIG. Since the side wire 11b is twisted, it is gripped by the teeth of the two adjacent pieces 12a and 12b depending on the fixing condition.

  In that case, as shown in FIG. 6 (A), the side line 11b is gripped from the entrance to the ridge line part of the divided part by the teeth of the piece 12b (not shown), and the divided part 11d is adjacent to the piece without contacting the piece. The side line 11b has a discontinuous gripping tooth trace as shown in FIG. 6 (B). FIG. 6B shows the tooth trace of the side line 11b. The tooth trace of the piece 12b is indicated by reference numeral 11a, and the tooth trace of the piece 12a is indicated by reference numeral 11c. Depending on the positional relationship between the pieces 12a and 12b, the number of the tooth traces 11c may be in a state where only two to five are gripped.

  When a repeated tensile load acts on the tension material thus fixed, each side line expands in proportion to the stress. At this time, the stress state of the side line during tension inside the wedge changes in accordance with the length of the wedge in the tensile direction. In general, the stress is 0 (zero) on the entrance side of the wedge, and on the exit side of the wedge. Since it is in the maximum tensile stress state, the amount of elongation is the largest on the outlet side. And the tension material inside the wedge extends according to the tensile stress, and its outer diameter size is also small although corresponding to the Poisson's ratio, so it becomes easier to move in the tensile direction on the outlet side. Yes.

  At this time, even in the side line 11b gripped by the two pieces 12a and 12b, the tensile stress is almost 0 (zero) on the inlet side end face, and a large tensile stress is acting on the grip part on the outlet side. . Since the section of the divided portion 11d between the piece 12b and the piece 12a is not gripped by the teeth of the piece, the section of the divided portion 11d also extends in the exit direction due to tensile stress. Therefore, the exit side grip portion of the side line 11b with the tooth mark 11c is a small amount due to the presence of the discontinuous divided portion 11d, the maximum tensile stress, and the repeated action of the tensile load. , Repeated elongation movement occurs.

  There is a possibility that the side line 11b may cause slight corrosion at the portion of the tooth mark 11c and fatigue fracture due to a small amount of repeated elongation and movement at the exit side grip portion of the piece. The cable fixing member according to the present invention has been proposed to solve such problems.

The gist for achieving the object by solving the above-mentioned problems of the cable fixing member according to the present invention is as follows:
In a fixing member that is a wedge that penetrates a tension material in a form of a stranded wire through a fixing cone and sandwiches the tension material by a plurality of divided bodies, an outlet in a tensile direction at an arc-shaped inner contact surface of the divided body That is, a part of the ridge line portion on the side is cut toward the exit.

The ridge line part to be cut is an ridge line part on the inlet side in which at least a stranded wire enters the inside of the divided body along the twist direction among ridge line parts on both sides of the divided body;
Cutting the ridge line part obliquely so as to gradually become deeper toward the exit;
The length of a part of the ridge line portion is about 1/3 of the entire length from the end on the outlet side;
Is included.

According to the cable fixing member of the present invention, there is no biting by the teeth of the piece on the outlet side in the pulling direction of the ridge line portion of the piece, which is a wedge divided body, and repeated fine corrosion corrosion is eliminated. In addition, the fine corrosion is caused by the ridge line portion on the inlet side where the stranded wire enters the inside from the side surface of the piece that is the divided body along the twist direction, so that at least a part of the ridge line portion is cut. It is. In addition, since the stranded wire has S-shaped twist or Z-shaped twist, it is possible to cope with both stranded wires by cutting a part of the ridge line portion on both sides of the piece, and there is no need to prepare a dedicated product. Parts management becomes easy.
Further, the cut state of the ridge line portion is cut obliquely so as to gradually become deeper toward the exit of the piece, so that, for example, processing of an existing piece becomes easy.
The portion where the fine corrosion is likely to occur is at most about 1/3 from the end surface on the outlet side of the entire ridge line on the side of the piece due to the contact condition between the stranded wire of the tension material and the piece. Therefore, the portion to be cut may be about 1/3 of the entire ridge line portion, and this can be improved efficiently.

  As shown in FIGS. 1A, 1B, and 2, the cable fixing member according to the present invention uses a tension member 11 made of a PC steel stranded wire as an example of a stranded wire, for example, a main tower of a cable-stayed bridge. In the anchor head of the fixing portion on the side or main girder side, the wedge is passed through the fixing cone cone and sandwiched by the pieces 1 as a plurality of divided bodies.

  A part of the ridge line portion 1a of the side portion on the exit side in the pulling direction a on the arc-shaped inner contact surface of the piece 1 (the side close to the opposing fixing portion is the exit and the opposite far side is the entrance) To cut. This cut portion is denoted by reference numeral 1b.

  As shown in FIG. 1 (B), the ridge line 1a is cut obliquely so as to gradually become deeper toward the exit side in the pulling direction a. If it does in this way, the existing piece 1 can be easily processed and it can be set as the product of this invention.

  The length b of a part of the cut portion of the ridge line portion 1a is at most about 1/3 of the total length from the end portion on the outlet side, as shown in FIG. This is because the PC steel stranded wire 11b is mainly S-twisted and abutted while being twisted on the inner abutting surfaces of the two pieces 1, and the range in which the teeth of the piece bite into the surface of the PC steel stranded wire This is because it becomes approximately 1/3 of the entire length of the ridge line portion 1a, and if the portion is cut, the biting of the teeth is surely prevented.

  In this embodiment, three pieces 1 are attached in the circumferential direction around the tension member 11, and as shown in FIG. 1C, the piece 1 is pulled in the pulling direction a in a conical through hole. Thus, the triangular protrusion 1d on the inner contact surface shown in FIG. 2B bites into the tendon material 11, and is fixed by preventing the tension material 1 from coming off.

  In the figure, the twist direction of the stranded wire of the tension material 11 is drawn by S-shaped twist, and in this case, the tooth mark 11c of the grip portion which is a weak point is one side at the left and right side portions at the exit portion of each piece 1, There is a possibility that three places become weak points in the three-piece piece. Naturally, when using a Z-twisted stranded wire, the weak side of the S-shaped twist is on the left and right, and the opposite side is the weak point. Therefore, cutting the ridge line portion on both the left and right sides of the piece 1 is convenient for use because there is no need to prepare a dedicated product corresponding to the twist direction. As a method of cutting the ridge line 1a, in addition to the above-described one embodiment, as shown in FIG. 3, the cut portion 1c may be formed by cutting at a certain depth.

  By using the wedge consisting of the piece 1 according to the present invention as a cable fixing member, as shown in FIG. 2 (B), at the contact portion between the piece 1 and the PC steel stranded wire 11b, the tensile direction a A slight gap is formed on the exit side of the steel plate, and the teeth of the piece 1 do not bite into the surface of the PC steel stranded wire 11b, and fatigue fracture due to fine corrosion is prevented.

It is the perspective view (A) of the piece 1 which comprises the wedge of the cable fixing member which concerns on this invention, a partial expansion detailed perspective view (B), and the front view (C) which shows a use condition. It is the side view (A) of the piece 1 which comprises the wedge of the cable fixing member of the same invention, and the side view (B) which shows a use condition. It is a side view of the piece 1 which concerns on another Example. In the conventional wedge 12, it is a perspective view (A) and (B) which show the division state made into 3 division and 2 division. It is a side view of the use state of the wedge 12 concerning a prior art example. It is explanatory drawing (A) of the fixing state by the wedge 12 which concerns on the same prior art example, and explanatory drawing which shows the mode of the tooth marks 11a and 11c of the strand wire 11b of the tension material 11. FIG.

Explanation of symbols

1 Wedge piece, 1a Ridge part,
1b cut part, 1c cut part,
1d triangular protrusion,
2 gap,
11 Tension material, 11a Tooth trace,
11b side wire (PC steel stranded wire), 11c tooth trace,
11d division part,
12 conventional wedges, 12a, 12b pieces,
12c Ridge line.

Claims (4)

In the fixing member which is a wedge that penetrates the tension material in the form of a stranded wire into the fixing cone and sandwiches the tension material with a plurality of divided bodies,
A part of the ridge line portion on the outlet side in the pulling direction in the arc-shaped inner contact surface of the divided body was cut toward the outlet,
A cable fixing member characterized by the above. The ridge line part to be cut is the ridge line part on the entrance side where at least the stranded wire enters the inside of the divided body along the twist direction among the ridge line parts on both sides of the divided body,
The cable fixing member according to claim 1. The ridgeline part was cut diagonally so that it gradually became deeper toward the exit,
The cable fixing member according to claim 1 or 2. The length of a part of the ridge line part is about 1/3 of the entire length from the end part on the exit side,
The cable fixing member according to any one of claims 1 to 3.

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