JP2807845B2 - Construction method of diagonal material for Stypanel Bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing a diagonal member for a stypanel bridge.

[0002]

2. Description of the Related Art In the construction of a cable-stayed bridge or a stay panel bridge, as a method of connecting a diagonal member such as a PC steel material between a vertical tower and a horizontal main girder, one end of the diagonal member is embedded in the main girder or the tower. Then, the other end of the diagonal material is penetrated to the tower side or the girder side, and the tension is fixed. .

[0003]

[Problems to be solved by the present invention] The above-mentioned conventional diagonal member construction techniques have the following problems. <B> In the method of embedding one end of the diagonal material in the spar and fixing the other end by tightening it on the tower side, the embedded end of the diagonal material must be buried at the same time as the concrete is cast. It is necessary to unfold the entire length of the diagonal material on the girder or on a support dedicated to mounting on the other end side of, and the construction is troublesome. <B> In the case where the diagonal material is fixed on the lower surface of the girder, the construction is extremely difficult if there is an obstacle below the girder. <C> When the diagonal material is settled on the tower side, it takes time and effort to move the jack, and large-scale equipment is required.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for installing a diagonal member of a stypan bridge which has excellent workability. is there.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for constructing a diagonal material for a stay panel bridge in which a diagonal concrete material is diagonally connected between a tower and a horizontal girder integrally projecting from the tower. One end of the PC cable is buried in the girder that overhangs, and another PC cable is slidably inserted into the top of the tower,
Connected between the ends of the two PC cables via a fixing device,
The method is characterized in that concrete is cast while exposing the fixing device to form a diagonal material, and after the concrete is hardened, one PC cable fixed to the fixing device is tensioned to introduce prestress into the diagonal material. Further, the present invention is characterized in that one end of the PC cable is fixed to the tower top, and one PC cable is tensioned through a fixing tool on the way between the tower top and the horizontal girder to introduce prestress into the diagonal member. I do.

[0006]

The present invention will be described below with reference to the drawings. In this example, a case will be described in which a stay panel bridge is constructed by employing a through system in which a PC cable is penetrated through a tower. <A> Construction of tower and horizontal girder As shown in FIG. 1, the tower 1 is constructed by a known construction method. At this time, as shown in FIG. 7, a saddle pipe 2 curved with a gentle curvature is buried at the top of the tower 1. As the saddle pipe 2, for example, a steel pipe having both ends opened can be used. Next, concrete is cast on the left and right sides of the tower 1 using the mobile work vehicle 3 and the horizontal girders 4 are sequentially extended. <B> Construction of diagonal material stage After the horizontal girder 4 has been extended by a certain length, stages 7 for diagonal material are constructed on both sides of the horizontal girder 4 as shown in FIG. The stage 7 is configured by a supporter or the like assembled along a planned installation line of the PC cable. <C> Divided arrangement of the girder side PC cable When the horizontal girder 4 projects, the girder PC cable 5a
Is buried in the horizontal girder 4. PC cable for girder 5
a is a PC steel stranded wire or the like, and a resistance plate is fixed and embedded at an embedded end thereof. The free end of the girder PC cable is inserted into an insertion hole 61 of the anchor head 6 as shown in FIG.
To settle. The anchor head 6 has double insertion holes 61 concentrically formed, and the insertion direction of the wedges 62 in each of the insertion holes 61 is reversed in the inner row and the outer row.
A set plate 63 prevents the wedge 62 from falling off. <D> Arrangement of tower side sheath When the setting of the girder PC cable 5a is completed, a long PC cable 5b is inserted into each saddle tube 2 of the tower 1 as shown in FIG. Guide to the left and right of the horizontal girder 4. Then, as shown in FIG. 9, each PC cable 5b
Into the insertion hole 61 inside the anchor head 6,
After tension is applied between the cables 5a and 5b, fixing is performed using the cone 64. At this time, the fixing end of the PC cable 5b is made to protrude from the anchor head 6, which will be described later, by an amount corresponding to the tension. Thereby, the continuous P between the tower 1 and the horizontal beam 4
This means that the C cables 5a and 5b have been installed. <E> Casting of diagonal concrete Next, as shown in FIG. 4, a formwork is assembled around the group of PC cables 5a and 5b, and concrete is cast to construct the stay panel 8. At this time, the continuous PC cable 5
a, 5b, at least one of the anchor heads 6 is surrounded by a box or the like so that the anchor heads 6 are not buried in concrete. <F> Secondary tension of PC cable After the concrete is hardened, a center hole type tension jack 9 is set via the curve chair 65 to the anchor head 6 in the notch 71 provided in the stay panel 8 as shown in FIG. Then, the PC strand 5b is gripped and tensioned. PC
The tension reaction force of the cable 5b is P via the anchor head 6.
Since the PC cables 5a and 5b are supported by the C cable 5a, the PC cables 5a and 5b can be simultaneously tensioned on the way of the stay panel 8 with the tower 1 interposed therebetween. Thereby, a predetermined prestress can be introduced into the stay panel 8. Further, while the anchor head 6 is exposed, the re-tensioning operation can be performed as needed. Finally, concrete is filled into the notch of the stay panel 8, and the stage 7 is dismantled to obtain the stay panel bridge shown in FIG. Note that, in order to effectively tension the two PC cables 5a, it is preferable to provide an unbonded type by sheathing the sheath before placing concrete. Also, both PC cables 5a,
The tension of 5b is performed at the time of cantilever construction of the horizontal girder 4, at the time of construction on the stage 7, or at the time of final tension, etc., to adjust the sectional force of each part and the level of the horizontal girder 4.

[0007]

[Other Embodiments] In the above embodiment, the through system in which a PC cable is passed through a tower has been described.
Of course, one end of the column may be fixed to the top of the tower 1.

[0008]

As described above, the present invention has the following effects. <a> Tension work of a PC cable can be easily performed on a girder in a favorable work environment. Therefore, even if there is an obstacle under the girder, the work can be performed, and the tension jack can be easily moved. <B> The PC cable can be re-tensioned as needed. <C> Since the tension is applied between the PC cables divided into a plurality of pieces, the PC cable is used when placing concrete in towers and girders.
PC compared to the conventional method that arranges the entire length of the cable
Easy placement of cables.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a construction method of extending a horizontal girder to the left and right of a tower.

FIG. 2 is an explanatory diagram when a girder PC cable is set on a horizontal girder.

FIG. 3 is an explanatory diagram when continuity is given to each PC cable via an anchor head.

FIG. 4 is an explanatory view when constructing a stay panel between a tower and a horizontal girder.

[Figure 5] Overall view when completed

FIG. 6 is a partial cross-sectional view of a tower top before a PC cable is inserted.

FIG. 7 is a partial cross-sectional view of the tower top with a PC cable inserted.

FIG. 8 is a sectional view of an anchor head to which a girder PC cable is fixed.

FIG. 9 is a cross-sectional view of an anchor head to which both PC cables are connected.

FIG. 10 is a longitudinal sectional view of a stay panel when a PC cable is tensioned.

Claims (2)

(57) [Claims] 1. A method for constructing a stay panel bridge in which a concrete diagonal member is diagonally connected between a tower and a horizontal girder extending integrally with the tower.
One end of the C cable is buried, a separate PC cable is slidably inserted into the tower top, connected between the ends of the two PC cables via a fixing device, and concrete is struck while exposing the fixing device. A method of constructing a diagonal material for a stay panel bridge, wherein a prestress is introduced into the diagonal material by tensioning one of the PC cables fixed to the fixing device after hardening of the concrete. 2. The PC cable according to claim 1, wherein one end of the PC cable is fixed to the tower top, and one PC cable is tensioned through a fixing tool on the way between the tower top and the horizontal girder to introduce prestress into the diagonal member. The method for constructing a diagonal member for a stay panel bridge according to claim 1, wherein: