JPH10266136A - Execution method of overhanging girder bridge using corrugated steel plate web - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct an overhanging bridge using corrugated steel plate webs, by attaching reinforcing steel members to the upper and lower edges of a corrugated steel plate and protruding it from an existing girder and partly bending the reinforcing steel member for adjustment thereof so that the vertical deflection of the front end of the corrugated steel plate coincides with the planed value. SOLUTION: When such a larger deflection than an expected deflection that the front end of a corrugated steel plate hangs down during the overhanging execution, is brought about, it is necessary to make shorter the upper side length of the corrugated steel plate than the lower side length. A hydraulic jack 23 is set between frames holding the right end girder member of the upper reinforcing frame 20a and stretched by supporting the reactive force at the right end of the frame and the compressive force is provided in the longitudinal direction or the girder. Since the corrugated steel plate is not smoothly deformed by the resistance against the buckling of the reinforcing steel member 12 connected to the upper end of the girder member, benders are put in steel members 12 between crests of the corrugated steel member or between valleys thereof and the jack is actuated to partly bend and deform the steel members 12 and adjust them. The upper and lower ends of the corrugated steel plates are embedded in cast-in-place concrete to form a bridge girder with a box-shaped section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for using a corrugated steel sheet for a box girder web (web) when a bridge is constructed by a cast-in-place block method, and an overhanging girder using a corrugated steel web. Related to bridge construction methods.

[0002]

2. Description of the Related Art An overhanging construction method of constructing a bridge by using a cantilever overhanging work device and alternately extending the bridge body from the bridge pier in the bridge axis direction while balancing the bridge body from side to side has been widely used. In this overhang construction method, a bridge body is divided into blocks of about 2 to 5 m in length and added to each other, so that a bridge with a long and long span can be easily constructed, and the space under the girder is regulated. There is such a feature that construction is possible without any.

In this overhanging work apparatus, a rail that can be relocated in the bridge axis direction is temporarily fixed on an existing bridge body block, and the work apparatus is mounted on the rail so as to be able to move forward and backward. And a scaffold are suspended and supported, assembling reinforcing bars and the like, and casting concrete to construct the block.
After constructing the block, the erection work device is advanced to the next block position, and the above steps are repeated, so that the bridge body is continuously extended and constructed. One example illustrating this method is shown in FIG. FIG. 13 is a side view showing the construction of the overhanging girder bridge. For the piers P ₁ and P ₄ , the overhanging of the superstructure has already been completed, and for the piers P ₂ and P ₃ , the erection work device 1
The upper structures 102 and 103 are shown extending one block at a time while balancing the bridge structure in the bridge axis direction from side to side using 00. Superstructure piers P _1, P ₄ 101,104
Is connected to each abutment with cast-in-place concrete using a shoring, waits for the bridges extending from the piers P ₂ and P ₃ , and connects them at the joints to complete a series of bridges. FIG.
Numerals 4 and 15 show cross sections of the concrete box girders 103 and 104 in the views of arrows HH and II in FIG. 13, respectively. The bridge having a concrete cross section shown in FIGS. 14 and 15 is excellent in noise reduction due to its large mass, and has features such as rust resistance. But,
It is heavy and disadvantageous in terms of earthquake resistance, and there are problems such as an increase in the size of the substructure such as piers.

[0004] From such a viewpoint, a bridge having a new structure type is required, and as one of the solutions, as a bridge taking advantage of the features and advantages of the overhanging girder bridge, a new combination of steel plate and concrete is used. A bridge having a corrugated steel web has been proposed and put into practical use. The feature of this new bridge is that, unlike the conventional steel girder bridge that simply combines steel plate and concrete, the steel plate is bent into a corrugated shape and arranged so that the corrugation repeats in the bridge axis direction and used as a web plate (web). The upper and lower floor slabs (flanges) are formed of concrete to form a box-shaped section girder. To date, there are two bridges of this type in Japan. One example of the construction method is a box girder with a simple girder structure of one span, which is cast in place on a production stand on the ground, and erected with a portal crane. Another example is a box girder of a continuous girder type. Is divided into predetermined lengths, built on the ground production stand behind the abutment, after one block is manufactured, extruded in the direction of the abutment and the pier, the next block is added to the back of the block, and the production is continued. A bridge is constructed by repeating extrusion.

[0005]

SUMMARY OF THE INVENTION The present invention uses the novel synthetic steel girder described above and applies an overhanging construction method as a construction method. The advantage of the overhanging construction method is that it is lightweight and economical. Is to construct a traditional bridge. But,
The girder using corrugated steel sheet as web (web) has a high degree of freedom of deformation only with corrugated steel sheet, and has sufficient rigidity to bear its own weight until concrete strength is developed by placing concrete on the upper and lower floor slabs. do not do. For this purpose, two rows of stiffening steel members are connected to the upper and lower ends of the corrugated steel plate serving as the girder material. It becomes necessary to restrain the bending moment and deformation of the load.

In the overhang construction method, one construction unit length of the bridge body is about 2 to 5 m in the bridge axis direction. Naturally, the length of the web material is manufactured as a block according to the construction unit length. It will be extended by welding or bolt joining. At this time, if the bridge body is repeatedly stretched and the concrete is laid on the upper and lower floor slabs and the bridge body is overhanging, and unexpected bending or upslending of the bridge body occurs, the bridge body overhangs from the adjacent pier. There is a risk that it may be difficult to connect the bridges between the piers due to the difficulty of connecting to the adjacent bridges due to the stepped bridge body and the steps.

[0007] Furthermore, there is a technically immature part to cope with the case where the horizontal alignment of the bridge draws a curve.
The overhanging girder bridge made of all-section concrete as shown in Fig. 13 has a well-established technique and can be relatively easily laid. However, when corrugated steel sheets are used for the web, The stiffening structure that maintains the rigidity during the bridge erection work becomes an obstacle and cannot be easily deformed.

It is necessary to solve this problem in order to develop a method of constructing a bridge having this new structure. The present invention provides a method of constructing an overhanging girder bridge using a corrugated steel web that solves this problem. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION The present invention utilizes a corrugated steel sheet having repeated irregularities as a web (web) of an overhanging girder bridge that cantileverly projects a bridge into blocks each having a predetermined length. When constructing a bridge girder with a composite structure of concrete and steel plate, stiffening steel is attached to the upper and lower edges of the corrugated steel plate that is to constitute the web, respectively, and overhangs the existing girder to reduce the vertical deflection of the tip of the corrugated steel plate. The stiffening steel material is locally bent and adjusted so that this deflection matches the planned value, and then the upper and lower edges of the corrugated steel sheet are buried in cast-in-place concrete to form a box. A method for constructing an overhanging girder using a corrugated steel web, wherein a bridge girder having a cross section is formed and an overhanging girder is constructed.

Further, in addition to adjusting the deflection so as to coincide with the planned value, the stiffening steel material is locally bent so that the horizontal bending of the corrugated steel sheet corresponding to the curved shape in the horizontal plane of the bridge shaft is performed. And a method for constructing an overhanging girder, characterized by providing The basic configuration of the present invention is to fine-tune the wave height and pitch of the wave of the corrugated steel sheet to cause a difference in the upper side length and the lower side length of the corrugated steel sheet, and to prevent the tip of the corrugated steel sheet that is cantilevered from sagging. Lifting is to be corrected so as to match the plan value, and in some cases, adjustment is made to match the plan value in consideration of lowering and raising. Further, the left and right pitches of the waves of the corrugated steel sheet are changed slightly to cause the beam to bend in the horizontal plane to obtain a change in the erection traveling direction.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. In this example, a bridge having a prestressed concrete structure is shown, but illustration of PC steel is omitted. Figure 10 is a side view of the overhang erection girder bridge embodiment of the present invention, shows a state in which the projecting erection using overhanging erection work apparatus 100 alternately bridge body to the left and right from the stigmas of the pier P ₂ It is a thing. FIG.
10 is a cross-sectional view thereof, taken along the line DD in FIG. 10, and FIG. 12 is a view taken along the line EE in FIG. Upper slab 41 and lower slab 42
Is a concrete, and a web plate (web) 10 for connecting it is a corrugated steel plate. An installed PC steel material is arranged on the upper floor slab 41, and a PC cable of an external cable is arranged in the box-shaped section 43 along the longitudinal direction of the bridge, but is not shown.

FIG. 1 is a perspective view showing an example of one corrugated steel sheet web 10. As shown in FIG. FIG. 2 is a plan view, and FIG.
It is a side view. The corrugated steel web 10 has a waveform in which irregularities are repeatedly formed in the longitudinal direction, and in order to secure its rigidity,
Two rows of stiffening steel members (reinforcing bars) 12 in the longitudinal direction that connect the ridges and valleys and the valleys and valleys at the upper and lower ends of the corrugated steel web 10 are welded. A joint bolt hole 14 for connecting the corrugated steel sheets to each other is formed in the longitudinal end of the corrugated steel sheet web 10. Further, reinforcing bar insertion holes 13 are formed near the upper and lower ends of the corrugated steel sheet web 10. The reinforcing bar insertion holes 13 are buried in the upper and lower floor slab concrete, and penetrate through reinforcing bars for integration with the concrete and for transmitting stress.

FIG. 4 and FIG. 5 are explanatory views of the method for adjusting the bending and deformation of the present invention. FIG. 4 is a sectional view taken along the line AA of FIG.
FIG. 5 is a side view. The stiffening frames 20a and 20b are mounted in two upper and lower stages using a part of the girder joint bolt hole 14 so as to sandwich the corrugated steel web 10 from the left and right. The tip of the corrugated steel sheet web 10 is gripped by a press fitting 25,
The push-in fitting 25 is connected to a hydraulic jack 23 via a rod 24, and the hydraulic jack 23 is connected to the stiffening frame 20.
Is supported by a connecting member 22 provided at the end of the connecting member 22. A large number of holding bolts 26 are provided at an intermediate portion of the stiffening frame 20, and the holding bolts 26 hold the tops of the peaks and the bottoms of the valleys of the corrugated steel plate, respectively, to increase the lateral bending rigidity of the corrugated steel plate.

FIG. 5 shows an example of the adjusting device. The adjusting method will be described in detail by taking as an example a case in which the tip of the corrugated steel sheet hangs down in the middle of the overhanging construction. If the bending is more than expected, the upper side length of the corrugated steel sheet needs to be shorter than the lower side length. To this end, in FIG. 5, the mounting bolt on the left end of the upper stiffening frame 20a is tightened via the bracket 21, and the mounting bolt on the right end of the upper stiffening frame 20a is loosely mounted. In the lower stiffening frame 20b, the mounting bolts on both the left and right ends are tightened.
A pushing metal 25 is formed by applying a reaction force to the connecting member 22 between the frames sandwiching the rightmost girder member toward the upper stiffening frame 20a.
The hydraulic jack 23 with the
The ends of the steel plates are inserted into the slits, and the hydraulic jack 23 takes a reaction force at the right end of the frame to extend it, thereby applying a compressive force in the longitudinal direction of the girder. In this state, the stiffening steel material connected between the ridges and the valleys at the upper end of the girder member resists buckling and the corrugated steel plate does not deform smoothly, so that the corrugated steel sheet is deformed as shown in FIG. The bender 30 is attached to the stiffening steel material between the peaks and the valleys of the steel plate, and the jack of the bender is operated to locally bend and deform the stiffening steel material 12. Vendor 30
As shown in FIG. 7, the two stiffening steel members 12 are mounted and operated at the position shifted by half a pitch of the wave of the corrugated steel sheet between the ridges and between the valleys. For example, the corrugated steel sheet web 10 can be shortened linearly. 8 and 9 are views of the bender 30 shown in FIG. 7 as viewed from the arrows BB and CC, respectively. The bender 30 is a two-point support part 31
And the hook 32 at the center thereof are locked to the stiffening steel material 12,
The stiffening steel material 12 is locally bent by the hydraulic jack 33. At this time, it was attached to the stiffening frame 20,
The holding bolts 26 shown in FIG. 6 are for holding the tops of the peaks and the bottoms of the valleys of the corrugated steel web 10 to suppress and adjust deformation. The holding bolt 26 is used for the stiffening frame 20.
Has a male screw 27 that is screwed into the female screw attached thereto, and the position of the head 28 that contacts the corrugated steel sheet web 10 can be adjusted. The position is fixed by a lock nut 29.

The operation of the bender 30 is more effective when the bender 30 is mounted at a position closer to the existing bridge. In other words, a small amount of bending (a reduction in the length of the girder) increases the amount of movement of the girder end. Also, in the case of a curved bridge, when bending a corrugated steel sheet in accordance with a curve, jacks are attached to both upper and lower stiffening frames 20 of the corrugated steel sheet inside the curve,
This is made possible by adjusting the holding bolt 26 in accordance with the curve and, at the same time, bending the stiffener 12 by attaching the bender 30 to the stiffener 12 inside the upper and lower curves of the corrugated steel sheet.

The stiffening frame 20 used in the present invention may be removed after suspending the girder material on the overhanging work vehicle, or may be removed after the strength of the upper and lower floor slab concrete is developed. This is preferable because deformation due to the above can be prevented. The above description is an example, and the stiffening steel material is a round steel, but is not limited to this.A flat bar, an angle steel, a square steel, etc. may be appropriately selected, and the length of the girder material is also adjusted. The jack can be pushed and pulled freely. Further, the number of mounting steps of the stiffening frame may be set to an appropriate number according to the girder height.

[0017]

According to the method of the present invention, the same advantages as the features and advantages of the conventional overhanging girder made of full-section concrete are utilized, and furthermore, the weight is reduced and the burden on the substructure is reduced. It is possible to construct a new composite bridge with excellent earthquake resistance.

[Brief description of the drawings]

FIG. 1 is a perspective view of a corrugated steel sheet according to an embodiment.

FIG. 2 is a plan view of a corrugated steel sheet of an example.

FIG. 3 is a side view of the corrugated steel sheet of the embodiment.

FIG. 4 is a view taken in the direction of arrows AA in FIG. 5;

FIG. 5 is a side view showing reinforcement of the corrugated steel sheet of the example.

FIG. 6 is a side view of the holding bolt of the embodiment.

FIG. 7 is a plan view showing the use of the vendor of the embodiment.

8 is a view taken in the direction of arrows BB in FIG. 7;

9 is a view as viewed in the direction of arrows CC in FIG. 7;

FIG. 10 is a side view of the overhanging girder bridge of the embodiment.

FIG. 11 is a view as viewed in the direction of the arrow DD in FIG. 10;

FIG. 12 is a view as seen in the direction of arrows EE in FIG. 10;

FIG. 13 is a side view of an overhanging girder bridge.

FIG. 14 is a view taken in the direction of arrows HH in FIG. 13;

FIG. 15 is a view taken in the direction of the arrow II in FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Corrugated steel plate web (belly plate) 12 Stiffening steel material (reinforcing bar) 13 Reinforcing bar insertion hole 14 Bolt hole 20, 20a, 20b Stiffening frame 21 Bracket 22 Connecting material 23 Hydraulic jack 24 Rod 25 Push-in fitting 26 Holding bolt 27 Male screw 28 hit Contact part 29 Lock nut 30 Bender 31 Support part 32 Hook 33 Hydraulic jack 41 Upper floor slab 42 Lower floor slab 43 Inside box girder cross section 100 Overhang work equipment 101-104 Upper structure (concrete box girder) 105 Abutment

Claims (2)

[Claims] 1. A stiffening steel material is attached to each of an upper edge and a lower edge of a corrugated steel sheet which is to constitute a web, and is extended from an existing girder.
The vertical bending of the tip of the corrugated steel sheet is detected, and the stiffening steel material is locally bent and adjusted so that the bending matches the planned value. Then, the upper edge and the lower edge of the corrugated steel sheet are located. A method of constructing an overhanging girder using corrugated steel webs, wherein the overhanging girder is constructed by embedding in a cast-in concrete to form a box-shaped bridge girder. 2. In addition to adjusting the deflection so as to match a planned value, the bending of the stiffening steel material locally causes the horizontal bending of the corrugated steel sheet corresponding to the curved shape in the horizontal plane of the bridge shaft. The method for constructing an overhanging girder using the corrugated steel sheet web according to claim 1, wherein: