JPH10266134A - Construction method of bridge utilizing stretched cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a bridge wherein a road for construction is not needed for transporting materials and mechanical equipment up to an intermediate pier, cost and construction period can be reduced, the design cross area force of a girder member during bridge construction is not made greater than that after bridge completion, and earthquake resistance of the bridge during construction can be improved. SOLUTION: The construction method of a bridge is composed of a process for stretching a cable 13 between abutments 11b, a process for fixing the cable 13 on piers 15a, 15b previously vertically provided between the abutments, and a process for successively transporting a plurality of precast members 20 as the cable 13 is made a track and continuously providing them between the abutment and the pier and between the piers. A member formed to previously precast a web member vertically provided from a lower floor board and an upper floor board as the precast member 20 may be employed, and after the precast member is continuously provided between the abutment and the pier, a process forming the upper floor board may be included on the web member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method of a bridge using an extension cable.

[0002]

2. Description of the Related Art Conventional bridges, particularly, a maximum span of 50 to 15 spans.
In a mountain bridge of about 0 m, a bridge is constructed by an overhanging erection method as shown in FIG. That is, a construction road 54 is constructed using a cable crane (not shown) to the pre-constructed intermediate pier 52, materials and equipment are transported through the construction road 54, and a tower crane is placed on the intermediate pier 52. The mobile work vehicle 51 is lifted by the tower crane 50 and installed on the intermediate pier 52, and a girder member 56a is erected by the mobile work vehicle 51 to construct the main girder 56.

[0003]

Mountain bridges are often constructed on steep terrain, and construction roads 5
When the construction road 4 is to be constructed, the construction road 54 tends to be long in length, resulting in enormous construction costs, destruction of the natural environment, and difficulty in constructing the construction road 54 itself. There is a problem that the construction period becomes long.

In the overhanging erection method shown in FIG. 10, the main girder 56, which is constructed while extending in both directions, is supported by only a single intermediate pier 52 during construction. it is, for example, when an earthquake as indicated by a double-headed arrow P occurs, vibrates largely left as double-headed arrow Q ₁ by the seismic response. Therefore,
In order to resist earthquakes, the required section force of the intermediate pier 52 may be larger than the design section force after completion of the bridge. In that case, reinforcement measures for the earthquake under construction are required, and construction costs increase. There is a problem of inviting.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has a problem that a construction road for transporting materials and equipment to an intermediate pier is not required. An object of the present invention is to provide a bridge construction method capable of shortening the construction period.

Another object of the present invention is to improve the seismic resistance of a bridge during construction without making the sectional force of the intermediate pier caused by an earthquake during construction of the bridge larger than the design sectional force of the intermediate pier after completion of the bridge. An object of the present invention is to provide a bridge construction method capable of causing the bridge to be constructed.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a step of stretching a cable between abutments, and a step of fixing the cable to a pier previously set between the abutments. A step of sequentially transporting a plurality of girder members constituting the bridge girder between the abutments using the cable as a track, and connecting the girder members to the abutment / pier and between the abutments.

Here, as the girder member in the present invention, a member in which an upper slab, a lower slab, and a web member for connecting the upper slab and the lower slab are formed in advance by precast concrete is used. You may adopt it.

In the present invention, a member formed by precasting a lower slab and an abdominal material erected from the lower slab in advance is adopted as the spar member. After the members are connected between the abutment and the pier and between the piers, a step of forming an upper floor slab on the abdominal material may be included.

Further, in the present invention, in the step of transporting a plurality of girder members constituting the bridge girder between the abutments using a cable as a track, as a traction means for transporting the girder member, for example, an endless winch, a single winch, Alternatively, a simple towing / transporting means such as a chill hole can be employed. In this step, transporting the girder member using the cable as a track means that the precast member is transported along the cable while supporting part or all of the load of the precast member with the cable. For example, if a means capable of sliding on the cable or a means capable of rolling on the cable is provided on the girder member, this step can be easily performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited thereto.
FIG. 1 is an explanatory view showing one step in order to explain the bridge construction method of the present invention, and FIGS. 2 (a) to 2 (c) are explanatory views showing steps subsequent to FIG. 3 (a) to 3 (c) are explanatory views showing steps subsequent to FIG. FIGS. 4A and 4B are partial cross-sectional views showing the positional relationship between the upper end of the intermediate pier 15a, the fixture 18 for fixing the PC cable formed here, and the girder member 20 passing therethrough. FIG. 5 is a side view showing a process for connecting the transported girder member 20 to the existing main girder 30, and FIG. 6 shows a process different from the processes shown in FIGS. FIG. 7 is an explanatory view shown, and FIG.
8 (a) and 8 (b) are explanatory views for explaining a process of on-site construction of the upper floor slab 35 'by the upper floor slab movable formwork 32. FIG. In particular, FIG. 8A shows the cut line a ₁ − in FIG. 8B.
FIG. 9 is a cross-sectional view in which a cross-sectional view taken along a ₁ , a ₂ −a ₂ is arranged on the left and right with a dashed-dotted line as a boundary, and FIG. .

There is.

In the bridge construction method shown in FIGS. 1 to 3, a PC cable 13 is stretched between the abutments 11a and 11b, and the PC cable 13 is connected to intermediate bridge piers 15a and 15b which are previously erected by a fixture 18. A plurality of girders 20 are sequentially conveyed by using the PC cable 13 as a track, and connected between the abutments 11a and 11b and the intermediate piers 15a and 15b and between the intermediate piers 15a and 15b to be connected to the main girder 30. Is constructed.

The construction method of the bridge and the equipment used in this method will be described in detail below. When constructing a mountain bridge, a cable bridge (not shown) is used to construct an abutment 11 without constructing a construction road as before.
a, 11b and the intermediate piers 15a, 15b are constructed, and the abutments 11a, 11b are fixed to the ground 40 with a plurality of ground anchors 15 and piles, and the PC cable 13 is fixed to the upper ends of the intermediate piers 15a, 15b. Frame 1 for temporary fixing
8a are provided. These two temporary fixing frames 18a
Is the main girder 30 in the girder width direction on each intermediate pier 15a, 15b.
4 (a) and 4 (b), a cable band 19 is provided at the upper end, and the cable band 19 is capable of inserting a plurality of PC cables 13 therein.
In addition, a cable that can integrally fix the PC cable 13 after insertion is used.

Next, as shown in FIG.
An endless winch 12 is installed between the endless winch 12 and a plurality of PC cables 13.
While being transported, is temporarily fixed by being inserted into the cable band 19, and the PC is connected from one abutment 11a to the other abutment 11b.
The cable 13 is erected, and then tension is introduced into the PC cable 13 using a tension jack. After the tension is thus introduced, a plurality of PC cables 1 are
3 are integrally fixed to form a construction saddle 18b as shown in FIGS. 4 (a) and 4 (b). This saddle for construction 18b is
The two temporary fixing frames 18a are formed of cast-in-place concrete so as to be buried respectively, and a clearance through which the girder member 20 can pass is secured between the two construction saddles 18b. The upper end surface of the construction saddle 18b has a projection 18 having a width that allows the roller 23d to roll.
b 'is provided, and the PC cable 13 is buried in the protruding portion 18b' and a rising gradient is provided from both sides toward the center.

Next, as shown in FIG.
An erection nose 21 is assembled on a, and the end precast member 17 is transported by the endless winch 12 and fixed to the abutment 11b. Then, as shown in FIG. 2 (b), the spar member 20 is raised and lowered by the erection nose 21, the upper end of the spar member 20 is engaged with the endless winch 12, and is rolled on the PC cable 13 to be conveyed. I do. Here, as each girder member 20 constituting the main girder 30, an upper floor slab 20a, a lower floor slab 20c, and an abdominal material 20b connecting the upper floor slab 20a and the lower floor slab 20c are prepared in advance in a factory or the like. A member made of precast concrete or the like is used. Also, as shown in FIGS. 4A and 4B, a conventional guide rail 22 and a conventional climbing device 23 are fixed to each beam member 20 in advance. That is, although not shown, the guide rail 22 includes a flange having a plurality of holes formed so as to extend in the axial direction, and is fixed to the abdominal member 20b by the fastener 24. The climbing device 23
The upper sliding portion 23a and the lower sliding portion 23c are formed so as to be fittable and slidable on the guide rail 22, and a pin (not shown) is provided in a hole provided in a flange of the guide rail 22. The upper sliding portion 23a is pivotally attached to the upper end of the jack 23b,
A lower sliding portion 23c is pivotally attached to a lower end of the jack 23b,
The lower sliding portion 23c is provided with a roller 23d via a bracket 23e. In such a conventional climbing device 23, the operation of extending the jack 23b and the operation of pulling out and inserting the pins in the upper sliding portion 23a and the lower sliding portion 23c are repeated as appropriate, so that the guide rail 22 is moved like a shark insect. It goes up and down along. The above-mentioned rolling of the girder member 20 on the PC cable 13 is performed by fixing the guide rail 22 and the climbing device 23 to the girder member 20, placing the roller 23 d of the climbing device 23 on the PC cable 13, This is realized by pulling the spar member 20 by the winch 12 and rolling the roller 23 d on the PC cable 13. Further, the girder member 20 is conveyed to the intermediate pier 15
a and 15b, the roller 23d moves from the PC cable 13 to the upper surface of the convex portion 18b ', and while rolling, the girder member 20 passes between the two construction saddles 18b. Roll on the cable 13.

The spar member 20 transported as described above is shown in FIG.
As shown in (b), the process of being connected to the end precast member 17 installed on the abutment 11b, and the beam member 20 being sequentially transported and connected to the previously installed beam member 20 is repeated, Thus, the main girder 30 is constructed so as to gradually project toward the intermediate pier 15b. Here, the connection process between the conveyed girder member 20 and the existing girder member 20 is shown in more detail in FIG. That is, before the spar member 20 is lifted by the erection nose 21, the PC steel bar 26 is protruded at predetermined positions on the left and right sides of the spar member 20, while the retraction jacks are provided above and below the end of the existing main girder 30. 25 is fixed. Then, when the girder member 20 is conveyed and approaches a position separated by a predetermined length from the end of the existing main girder 30, the PC steel bar 26 is inserted into the retraction jack 25, and the girder member 20 is retracted by the retraction jack 25. Then, it is connected to the end of the existing main girder 30.

The connecting step of the girder member 20 and the transporting step are repeated, and as shown in FIG. 3A, the main girder 30 moves beyond the intermediate pier 15b to the center of the intermediate piers 15a and 15b. Then, the connecting step and the transporting step of the girder member 20 are repeated so that the main girder 30 extends from the intermediate pier 15a toward the abutment 11a, and the intermediate pier 15a and the abutment 11a are repeated.
When the main girder 30 is erected between the PC and the PC, the PC cable 13 and the endless winch 12 are removed.

Next, from the intermediate pier 15a to the main girder end 30
The erection nose 21 is moved to the intermediate pier 15a in order to erection of the girder member 20 toward a.
As shown in (b), the girder member 20 is lifted by the erection nose 21, hung to a predetermined height, and connected to the main girder end 30b. Then, while sequentially moving the erection nose 21 in the direction of erection and erection, the connecting process of the girder members 20 is repeated until the main girder end 30b reaches the main girder end 30a. When the main girder 30 is erected between the intermediate piers 15a and 15b, finally, as shown in FIG. 3 (c), a pier such as a ground cover or a railing is provided using the pier work truck 22. Then, the bridge is completed.

In the bridge construction method, instead of the girder member 20, a girder member (for example, a girder member 35 described later) in which the upper slab is formed from cast-in-place concrete may be used. By using a movable form device 32 to be described later, an upper floor slab can be formed.

Next, a method different from the method shown in FIGS. 1 to 3 will be described with reference to FIG. In the construction method of the bridge of FIG. 6, similarly to the construction method shown in FIGS. 1 to 3,
Abutments 11a and 11b and intermediate piers 15a and 15b are constructed, an endless winch 12 is installed between the abutments 11a and 11b, and a PC cable 13 is erected using the endless winch 12 to introduce tension into the PC cable 13. After that, the construction saddle 18b is formed. Here, as the girder members 35 constituting the main girder 30, as shown in FIGS. 7 and 8, a lower floor slab 35 c and this lower floor slab 20
c is integrally formed in advance with precast concrete or the like, and an upper frame 35a is provided at the upper end of the web 35b. A member formed and formed is adopted.

Then, the guide rail 22 and the climbing device 23 are fixed to the beam member 35.
As shown in the above, the gantry (not shown) installed on the abutment 11a
Is provided, and the girder member 35 is raised by this installation base,
The upper end thereof is engaged with the endless winch 12, and the roller 23d is rolled on the PC cable 13 so that the spar member 35
Is transported. In the intermediate pier 15a, the conveyed girder members 35 are sequentially connected so as to project in both directions to form the main girder 31a, 31b.
In the above, the main girder 31c, 31d is also extended and installed in both directions, the main girder 31a is extended to the abutment 11a, the main girder 31b and the main girder 31c are extended until they are connected to each other, and further, the main girder 31d is abutment. If it is extended until it reaches 11b, the erection process of the girder member 35 is completed. Here, as shown in FIG. 6, the height of the girder member 35 at the time of conveyance is determined by the main girder 31a, 31.
When the heights of the beam members 35, 31c and 31d are significantly different from each other, the climbing device 23 is moved up and down along the guide rails 22 as shown in FIG. Then, the height of the beam members 35 is adjusted to the height of the end of each of the main beams 31a, 31b, 31c, 31d, and then connected to each other.

In parallel with the step of erection of the spar member 35, a step of constructing the upper floor slab 35 'is also performed.
When the construction process is completed, the bridge is completed. Here, in the construction process of the upper floor slab 35 ′, a caster 32 e is provided at the lower end of the support of the frame 32 a, as shown in FIG. The frame member 32d is supported by the scaffold 32c, and the form member 32d is formed by using a member whose height is appropriately adjustable.

In the bridge construction method of the present invention, the abutment 11
A cable 13 stretched between a and 11b is an intermediate pier 15
a, 15b, these abutments 11a, 11b
b, the cable 13 and the intermediate piers 15a and 15b are integrated as a frame having a predetermined rigidity. Therefore,
During construction of the main girder, the intermediate piers 15a, even when the ground motion, such as a double arrow P in FIG. 9 is applied to 15b, intermediate pier 15a due to the seismic response, vibration Q ₂ and 15b, the cable 1
3 is suppressed by the tension T. Therefore, even in an unstable structure where the main girder is supported only by a single intermediate pier in the overhanging erection process, the required sectional force of the intermediate pier under construction is larger than the design sectional force after completion of the bridge There is no need for reinforcement measures against earthquakes during construction, so construction costs can be reduced.

[0025]

According to the bridge construction method of the present invention, since the girder member is transported using the cable stretched between the abutments as a track, a construction road constructed by the conventional method is not required. Therefore, the construction cost and the construction period can be reduced. Also, since part or all of the weight of the beam member being transported is supported by the cable, a traction device used for transporting the beam member, for example,
The load borne by devices such as endless winches is reduced,
Therefore, it is possible to facilitate the process of transporting the girder members and to simplify these devices.

In the present invention, since the cable stretched between the abutments is fixed to the pier, the abutment, the cable and the pier are integrated like a frame, and a predetermined rigidity can be obtained here. Therefore, even if an earthquake occurs while the main girder is being constructed to extend from the pier, the vibration of the pier due to the earthquake response can be suppressed, and the seismic resistance of the bridge under construction can be improved. The required cross-sectional force of the intermediate pier during the overhanging construction can be reduced, and the construction cost can be reduced.

Further, in the present invention, a member formed by precasting a lower deck and a web material standing upright from the lower deck is adopted as a girder member, and this girder member is used as an abutment / abutment.
If the process of forming the upper floor slab on the abdominal material after the connection between the piers and the piers is performed, the load on the girder member during the transportation can be reduced, and the weight burden of the cable is reduced. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one step of a bridge construction method according to the present invention for explaining the method.

FIGS. 2 (a) to 2 (c) are explanatory diagrams showing steps subsequent to FIG.

FIGS. 3 (a) to 3 (c) are explanatory views showing steps subsequent to FIG. 2;

4 (a) and 4 (b) show the upper end of the intermediate pier and the P formed here.
FIG. 4 is a partial cross-sectional view showing a positional relationship between a fixture for fixing a C cable and a girder member passing therethrough.

FIG. 5 is a side view showing a process when the conveyed girder member is connected to an existing main girder.

FIG. 6 is an explanatory view showing a step different from the steps shown in FIGS. 1 to 3;

FIG. 7 is a front view showing a climbing mechanism that raises and lowers the beam member.

8 (a) and 8 (b) are explanatory diagrams for explaining a process of on-site construction of an upper floor slab using a movable mold for the upper floor slab.

FIG. 9 is a side view schematically showing a bridge on which an earthquake motion has acted in a construction process.

FIG. 10 is a side view showing a conventional overhang construction method.

[Explanation of symbols]

 11a, 11b Abutment 13 PC cable (cable) 15a, 15b Intermediate pier (pier) 18 Fixture 20 Girder member (precast member) 20a Upper floor slab 20b Abdominal material 20c Lower floor slab 35 Beam member 35 'Upper floor slab 35b Abdominal material 35c Lower Floor slab

Claims (2)

[Claims] 1. A step of stretching a cable between abutments, a step of fixing the cable to a pier previously erected between the abutments, and using the cable as a track to connect a plurality of girder members constituting a bridge girder. A step of sequentially transporting the bridges between the bridges and connecting them between the abutments / piers and between the piers. 2. A member formed by precasting a lower slab and an abdominal material erected from the lower slab in advance are used as the girder members, and the girder members are used between abutments / piers and between piers. 2. The method according to claim 1, further comprising the step of forming an upper floor slab on the web material after the bridge is connected to the bridge.