JP2005061064A - Curved road surface corresponding type box girder, and form device and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curved road surface corresponding type box girder prevented from concentration of bending stress on an intermediate part in a bridge axis direction caused by twisting without causing unnatural twisted formation of a box girder body part (a lower floor slab and a web) even if both end parts in the bridge axis direction are twisted. <P>SOLUTION: In one end face shape of the box girder, intersections of the end faces of the webs 4 and the end face of an upper floor slab 2 formed using the end face of an existing box girder as a form are made A, B, and intersections of the end faces of the webs 4 and the end face of the lower floor slab 3 are made C, D, whereas the other end face shape of the box girder is twisted by a prescribed angle with the end face center of the upper floor slab 2 as a rotational center O, and the end face of the lower floor slab 3 is displaced while keeping parallel with the end face of the upper floor slab 2, so that the end faces of both webs 3 intersect the end face of the lower floor slab 3 and the end face of the upper floor slab 2 at displaced intersections A-1, B-1, C-1, D-1. Both end faces of the box girder are thereby formed in non-identical shape from the bridge axis direction view. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a precast bridge girder block (hereinafter referred to as a curved road surface-compatible box girder) installed on a curved road surface such as a viaduct, a formwork apparatus thereof, and a manufacturing method thereof.

  The background art will be described first. When constructing viaducts with PC box girders, the precast segment method is being frequently used as a rational construction method that enables high durability, high-speed production of the box girders and reduction of production costs. The features of this construction method are as follows: (1) Construction of PC box girders in the yard close to the construction site, while building them efficiently and sequentially. Since the box girders can be built and installed in parallel, the construction period can be shortened. Yes, it can contribute to reduction of construction period.

(2) Since box girders are manufactured in a well-equipped yard, centralized management of products is possible. (3) Mechanization of the formwork device for box girder production and labor saving by continuation of the same work are possible.

  As a manufacturing method that enables labor saving of the PC box girder, there is a short line match cast method. This short line construction method is already known by a method of repeatedly producing a series of bridge girders (box girders) in a state (segment) by a mechanized formwork device (for example, JP-A-8-120620). .

  A case where the box girder 1 having a cross-sectional structure as shown in FIG. 12 is manufactured by the short line method will be described by dividing it into steps (1) to (6). The box girder 1 is configured by connecting the upper floor slab 2 and the lower floor slab 3 with the webs 4 on both sides, and the inside surrounded by the upper and lower floor slabs 2 and 3 and the web 4 is a hollow portion 5. Hereinafter, the lower girder 3 and the web 4 are referred to as a box girder body 6.

  The first process is a new installation (a box girder constructed in the current process) using one end face of the existing girder 1 (the box girder constructed in the previous process is called an existing one) as one end face formwork of the formwork device. The box girder is newly completed), and the outer frame is released outward, and the inner frame forming the hollow portion 5 of the box girder 1 is mounted on the carriage and moved in the axial direction. It is a frame process.

  In the second step, the end faces of the existing box girder and the new box girder are separated from each other, and both box girders placed on the carriage are sequentially moved to the next step for a predetermined distance. As a result, the existing box girder becomes a finished product and exits the formwork device, and the new box girder moves to the position of the existing box girder in the next process, and one end surface for the new box girder to be manufactured in the next process Functions as a formwork.

  In the third step, a reinforcing bar unit similar in shape to a box girder is suspended from above and arranged at a predetermined position.

  In the fourth step, the inner mold is moved and moved to a predetermined position for a new box girder to be manufactured next.

  In the fifth step, concrete is placed between the outer mold frame and the inner mold frame.

  In the sixth step, the box girder is completed. Thereafter, the process returns again to the first step.

According to the short line construction method described above, one end face of an existing box girder is used as an end face formwork of a box girder to be newly produced, and is produced sequentially, so that the formwork apparatus can be mechanized and the same work The labor saving is achieved by continuously performing the above. Moreover, the junction part in the box girder manufactured with the said construction method becomes the same shape, and at the time of erection, an epoxy resin-type adhesive material is apply | coated to the joint surface of each box girder, and adhesiveness and water stop are ensured.
JP-A-8-120620

  The short line / match cast method is a method for manufacturing box girders that can save labor, but the formwork used in this method is an inner formwork and an outer formwork, and both end formwork is a fixed arrangement method. Therefore, the shape of both end faces of the box girder manufactured by this conventional formwork apparatus is the same end face shape. Therefore, there is no problem when building a straight road surface with a box girder manufactured by this formwork apparatus, but when building a curved road 7 as shown in FIGS. 13A and 13B, a conventional box girder is used. 1 is not an ideal cross-sectional structure.

  That is, in the curved road 7, the slope of the straight road surface gradually increases from zero at first, the slope of the straight road surface returns to zero again, and the curved road ends. From the end to the end point, each box girder 1 is constructed by gradually inclining in accordance with the curvature of the road that curves with the axis as the axis of rotation.

  Conventionally, the curve-compatible box girder has been manufactured by a short line method. However, with the curve-compatible box girder manufactured by the conventional method, the end face shape of both ends of the box girder is the same in manufacturing, and therefore, unnatural twist between the both ends of the box girder and the middle part However, there is a problem that the bending stresses are easily concentrated and the webs of the box girders arranged along the curve at the time of installation are not aligned.

  More specifically, as shown in FIG. 12 (b), the curve-corresponding box girder 1a is constructed in such a manner that each box girder 1a is tilted and gradually inclined with the axis as a rotation axis. The structure of the box girder itself is changed compared to the standard box girder so that there is no step between the upper floor slabs between the inclined box girders. To do. In the curve-corresponding box girder 1a of FIG. 12B, the dotted line indicates the twisted position of the one end face using the existing box girder in the short line method, and the solid line indicates the twisted position of the other end face.

  As described above, when a curve-compatible box girder in which both axial ends of the upper floor slab are twisted with each other is manufactured by the conventional short line method, bending stress is concentrated in the axial middle portion of the box girder as described above. It is easy to do. That is, in the conventional short line construction method, the entire forming mold has a completely fixed structure. In particular, the upper floor formwork (bulkhead) for forming the other end face of the upper floor slab opposite to the one end face of the existing box girder is used. ) Including all the end surface molds were completely fixed to the fixing frame (bulkhead fixing frame), so when both ends in the axial direction of the upper floor slab were twisted together, the both end surface molds had the same shape Will be twisted.

  In this way, both end surface molds are twisted while maintaining the same shape, and when the inner and outer molds are arranged between the both end surface molds, both end surfaces of the inner and outer molds are also twisted together. It is arranged to be twisted so as to align with the formwork, but when both ends of a predetermined length object of the same diameter over the entire length are forcibly twisted, the unnatural twist generated in the object causes an unnatural twist between the ends. By the same principle that unnatural torsional stress is generated, the same problem is included in the curved box girder that is formed.

  Therefore, when a curve-compatible box girder in which both ends in the bridge axis direction are twisted with each other according to the conventional technology, the both ends in the bridge axis direction of the upper floor slab are twisted with respect to each other. Although satisfying the function, the box girder main body (both webs and lower floor slab) will be unnaturally twisted from one end to the other, and the twisting stress will tend to concentrate in the axial middle part of the box girder. It was a box girder structure.

  The present invention has been proposed in order to solve the above-described problems. In a box girder corresponding to a curved road surface in which the crossing gradient of the upper floor slab is changed, the box girder main body (both webs and lower floor slab) is provided. An object of the present invention is to provide a box girder that is not unnaturally twisted and formed from one end to the other end, and a formwork apparatus and a manufacturing method for manufacturing the box girder.

  In order to achieve the above object, the present invention is configured as follows.

1st invention consists of the upper floor slab and the lower floor slab, and the web which connects an upper and lower floor slab, and twists the bridge shaft direction both ends of a box girder by a predetermined angle, and is a curve road surface corresponding type | mold formed by a short line system. In the box girder, the intersection of the upper floor slab end surface and the web end surface formed with the end face of the existing box girder as the mold on one end side is defined as (A) and (B), and the intersection of the lower floor slab end surface and the web end surface is (C), (D) The box girder one end surface shape is twisted at a predetermined angle with the center of the upper floor slab end surface as the rotation core (O), and the lower floor slab end surface is parallel to the upper floor slab end surface. Intersection (A-1) in which both web end faces, lower floor slab end faces, and upper floor slab end faces are displaced relative to the intersections (A), (B), (C), (D) by keeping the displacement. , (B-1), (C-1), (D-1) are provided so as to cross each other, and the box girder both end faces when viewed in the bridge axis direction Wherein the is formed in a non-identical shape, over the other end surface from the box girder end surface, it is formed box girder profile continuously.
Further, the second invention is a formwork device by a short line method for producing the curved road surface-compatible box girder according to the first invention with the outer mold frame, the inner mold frame and the both end surface mold frames, The other end surface formwork arranged opposite to the one end face formwork composed of the end face is composed of the upper floor slab end face formwork and a plurality of box girder body end face formwork. Arranged in parallel with the upper beam for supporting the formwork provided on the frame of the apparatus, and the center of the upper form plate end face formwork is pivotally supported by a support shaft protruding laterally from the upper beam for supporting the formwork, and Both end portions of the upper floor slab end face formwork are connected to an expansion / contraction operation shaft of a gradient adjusting jack provided on the gantry, and are provided rotatably with the support shaft as a rotation core. The plurality of box girder body end face formwork Is provided so that it can be displaced and arranged corresponding to the rotational displacement of the end plate formwork of the upper floor slab.

The third invention is a method of manufacturing the curved road surface type box girder of the first invention by the short line method of the following process.
(First step) In the state where the new box girder is completed with the axial end of the existing box girder constructed in the previous process as a part of the mold, the outer mold is allowed to escape outward and the box girder The inner mold forming the hollow portion is moved in the axial direction to be removed.
(Second process) The existing box girder is completed by separating the end faces of the existing box girder and the new box girder in the axial direction and moving the box girder to the next process in the axial direction sequentially. And the new box girder is moved to a position to be the other end face form frame forming the end face of the box girder to be manufactured in the next process.
(Third step) A reinforcing bar unit similar in shape to a box girder is placed at a predetermined position.
(Fourth step) The inner mold is moved in the axial direction and moved to a predetermined position for a new box girder to be manufactured next.
(Fifth step) Rotation of the upper floor plate end surface mold on the other end surface arranged in parallel with the one end surface mold formed by the end surface of the existing box girder on the axis of the upper floor plate end surface mold Inclined by a predetermined angle around the core, and corresponding to the inclined upper floor slab end face mold, the web girder body part end face mold, the web end face mold, the lower floor slab end face mold, and the corner The upper and lower end surface formwork is rearranged to a predetermined part, and concrete is placed in the formwork including the end face formwork, the outer formwork and the inner formwork.
(Sixth step) A box girder is completed.

  The present invention relates to a curved road surface type box girder, and the upper floor slab is twisted at a predetermined angle from one end side to the other end side in the axial direction, and can smoothly correspond to the curved road surface. Since the web is displaced in parallel with the plate, and both webs are configured to keep the vertical length and follow the displacement of the upper floor plate and the lower floor plate so that they are displaced. Both ends of the intermediate part in the axial direction, especially the two webs and the lower floor slab, which are the box girder main body, are twisted evenly and reasonably in a natural form as a whole. A box girder corresponding to a curved road surface that is the most rational in terms of structural mechanics without being concentrated can be constructed.

Further, according to the formwork apparatus and the manufacturing method of the present invention, the upper end plate end formwork (bulk head) is rotated by a predetermined angle around the rotation core, and the web end face formwork and the lower floor end face formwork are By providing in a predetermined arrangement, a curved road surface type box girder in which a predetermined twist is applied to the upper floor slab can be easily manufactured in the factory.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 (a) and 1 (b) show a box girder 11 manufactured by a formwork apparatus (described later) using a short line method. FIG. 1 (a) shows one end face (11a) of the standard type, and FIG. 1 (b) shows the other end face 11b of the curved road surface type. FIG. 1 (c) shows a curved road surface corresponding box girder 11 according to another molding example in one figure, and shows that the both ends of the box girder have non-identical shapes. The other end surface side end surface is indicated by a dotted line 11d.

  More specifically, in FIGS. 1 (a) and 1 (b), the box girder 11 is configured by connecting the upper floor slab 2 and the lower floor slab 3 with the webs 4 on both sides, and the upper and lower floor slabs 2, 3 and The inner side surrounded by the web 4 is a hollow portion 5. The lower girder 2 and the web 4 are referred to as a box girder body 6. In the standard end face of the box girder 11 in FIG. 1A, the left and right of the center line passing through the axis are symmetric. That is, the cross gradient of the upper floor slab 2 is zero with respect to the box girder body 6. The straight road is constructed by using such box girders 11 whose crossing gradients at both ends of the upper floor slab 2 are zero. In the box girder end face 11 b corresponding to the curved road surface shown in FIG. 1B, the upper floor slab 2 is configured to have a transverse gradient with respect to the box girder main body 6. In the present invention, the box girder 11 can be manufactured using a novel formwork apparatus (shown in FIGS. 4 to 13) by a short line method.

  An example of the size of the box girder 11 shown in FIGS. 1A and 1B will be described. The width dimension of the upper floor slab 2 is 7.8 m, the length is 3.0 m, and the width of the lower floor slab 3 is The girder height from the upper floor slab 2 to the lower floor slab 3 is 4.5 m and 2.0 m. Of course, it may be formed in dimensions other than those described above.

  Here, the structural features of the curved road surface type box girder of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). Here, FIGS. 1 (a) and 1 (b) are described as showing one end face and the other end face of the same box girder (assuming a box girder at a portion where a curved road surface starts from a straight road surface). . FIG. 1 (a) shows one end face of a box girder formed by using the existing box girder end face as a mold on one end side in the short line method, and FIG. 1 (b) shows the main element of the present invention. The following description will be made on the assumption that the other end face of the box girder that is twisted and formed by the formwork apparatus described later is shown.

  In the box girder 11 of FIGS. 1 (a) and 1 (b), the upper floor slab 2 is formed by twisting one end of the bridge axis direction by a predetermined angle, and the end face of the existing box girder shown in FIG. On the one end face side of the box girder formed as a mold, the intersection of the end face of the upper floor slab 2 and the end face of the web 4 is (A), (B), and the intersection of the end face of the lower floor slab 3 and the end face of the web 4 is ( C) and (D), and the shape of the other end surface 11b of the box girder 11 shown in FIG. 1 (b) with respect to the shape of the one end surface of the box girder is the rotation core (O) And twisting a predetermined angle and displacing the end surface of the lower floor slab 3 in parallel with the end surface of the upper floor slab 2, and the intersections (A-1), (B-1) where the end surfaces of both webs 4 are displaced, In (C-1) and (D-1), by providing the end face of the lower floor slab 3 and the end face of the upper floor slab 2 so as to intersect with each other, the shape of both ends of the box girder in the bridge axis direction is not the same. Is formed into a shape over the other end surface from the box girder end surface, box girder profile are formed continuously.

  In the curved road surface corresponding type box girder 11 configured in this way, the upper floor slab 2 is twisted at a predetermined angle from the axial one end surface 11a side to the other end surface 11b, and can smoothly correspond to the curved road surface. At this time, the lower floor slab 3 is displaced while maintaining parallel to the upper floor slab 2, and both webs 4 are displaced following the displacement of the upper floor slab 2 and the lower floor slab 3 while maintaining the vertical length thereof. The both ends of the box girder 11 in the middle of the axial direction of the box girder 11, in particular, the both webs 4 and the lower floor slab 3 constituting the box girder main body 6 are uniformly and The twisted portion is reasonably natural, and the twisted portion does not concentrate locally in the middle portion of the box girder 11 in the axial direction, so that it is possible to construct a box girder corresponding to a curved road surface that is most rational in terms of structural mechanics.

  When the curved road surface type box girder 11 according to the present invention is installed to construct a curved road, the most rational curved road can be constructed in terms of structural mechanics, the strength is excellent, and the web 4 is vertical. There is also an effect that no step is generated between the webs of the box girders arranged along the curve.

  In the case where the curved road surface-compatible box girder 11 according to the present invention is manufactured by the short line method, it cannot be manufactured by the conventional formwork apparatus, and in particular, a new apparatus is required for the end face formwork.

  Hereinafter, the configuration improved by the present invention will be described with reference to FIGS. In addition, detailed description is abbreviate | omitted about the point which can apply the well-known formwork in the conventional short line construction method.

  FIGS. 2 to 5 show displacement forms of end face formwork in other parts when rotating the upper floor end face formwork (bulk head) when the transverse gradient of the box girder is changed in the formwork apparatus used in the short line construction method. It is explanatory drawing which shows. 6-11 is a figure which shows the mechanism which rotates an upper floor slab end surface formwork (bulk head).

  In the formwork apparatus used for the short line method, the formwork is constructed by assembling a plurality of inner and outer formwork in accordance with the inner and outer shape of the box girder 11b. That is, the plurality of form plates are: an upper flat outer form plate that constructs the upper surface of the upper floor slab 2, a lower flat outer form plate that constructs the lower surface of the lower floor slab 3, and a flat on both sides that constructs both outer surfaces of the web 4 It consists of an outer mold plate, a ceiling surface of the hollow portion 5, inner surfaces on both sides, and an inner bottom frame, and in addition to this, one end surface mold frame in the axial direction of the box girder 11 and the other end surface mold frame. . Each of the outer mold form and the inner mold form is publicly known and is not shown. In the following, an upper floor end face form form (bulk head) 13 and a main body part (web) that form the main part of the form work apparatus 12 according to the present invention will be described. The configuration of the end face formwork of the lower floor slab will be described.

  In the short line construction method, one end surface of an existing box girder functions as an end face formwork of a box girder to be manufactured in the next process.

  6 to 11, FIG. 6 is a front view of the mold apparatus 12, FIG. 7 is a plan view, and FIG. 8 is a side view. In each figure, a mold fixing frame 14 formed by assembling a plurality of frames is arranged on the left and right sides at a predetermined interval, and the upper beam for supporting the mold is interposed between the left and right mold fixing frames 14. 15 and the lower beam 16 for supporting the formwork are installed horizontally.

  A support column 18 rises from the upper end of the upper horizontal frame 17 in the left and right mold fixing frames 14, and a support pin 20 (see FIG. 9) is provided at the lower end of the upper horizontal arm 19 provided at the upper end of the left and right support columns 18. The slope adjusting jack 21 is pivotally attached to the left and right ends of the upper floor slab end face mold 13 at the lower ends of the slope adjusting jacks 21 arranged on the left and right. An inner mold frame for constructing the hollow portion 5 of the box girder end surface 11b (shown in FIG. 1b) is arranged at the lower part of the upper floor plate end surface mold frame 13, and the inner mold frame and a carriage that moves on the inner mold frame Are omitted in the figure.

  At the center of the mold support upper beam 15, a mold rotation core rod 22 penetrates in the lateral direction, and this mold rotation core rod 22 is arranged in parallel with the mold frame support upper beam 15. The center part of the provided upper floor slab end face formwork 13 is supported. Therefore, by adjusting the heights of the respective gradient adjusting jacks 21 arranged on the left and right, the upper floor slab end face formwork 13 can be inclined to an arbitrary inclination using the mold rotation core rod 22 as a rotation core. A box girder 11 as shown in FIG. 1 in which a predetermined transverse gradient is given to the box girder body 6 in combination with the end face formwork of the part can be manufactured.

  When the transverse gradient of the upper floor slab end formwork 13 in the mold apparatus 12 is changed, it can be arbitrarily finely adjusted by performing adjustment using the gradient adjusting jack 21. The gradient adjusting jack 21 has the rotation axis (core frame rotating core rod 22) of the upper floor plate end form frame (bulk head) 13 at the center of the fixed frame (form frame supporting upper beam 15). The end side of the gradient adjusting jack 21 has a support structure with upper and lower pins 20 in consideration of misalignment due to rotational movement.

  In FIG. 6, an inner mold 29 for forming a hollow portion of a box girder is disposed below the upper floor slab end face mold 13, and the web end face mold 24, the lower floor slab end face mold 26 and the like are arranged. Although these are held by the formwork holding material 28, these are well known and will not be described in detail.

  When manufacturing the box girder 11 corresponding to the curved road surface, as shown in FIG. 2 to FIG. A transverse gradient of the upper floor slab 2 in the box girder 11 to be manufactured is determined by rotating the core rod 22) about the rotation axis to the right or left by a predetermined angle. Correspondingly, the web end face formwork and the lower floor end face formwork are also displaced and arranged. This will be described below.

  2 to 5, the left and right web end face molds 24, the left and right corner part upper end face molds 25, the lower floor slab end face molds 26, and the left and right corner part upper end face molds 25 are all divided units. It is a member. Then, with the rotational displacement of the upper floor slab end form mold 13, the unit members are displaced and arranged at predetermined positions and assembled to assemble the entire end form mold of the main body 6 of the curved road surface type box girder 11. To assemble.

  FIG. 2 shows an arrangement form of the end face formwork when producing the standard box girder end face, and the left and right web end face molds with respect to the upper floor end face formwork 13 in the horizontal arrangement (when the transverse gradient is constant). The frame 24, the left and right corner portion upper surface mold frame 25, the lower floor slab end surface mold frame 26, and the left and right corner portion lower end surface mold frames 27 are arranged at the positions shown in the drawing. A standard box girder can also be formed on the entire form including the arrangement of the end face form.

  Next, when the box girder corresponding to the curved road surface in which the upper floor slab is twisted by rotating the upper floor slab end face mold 13 around the core rod 22 for mold rotation, first, FIG. As shown in a), the left and right web end face molds 24, the left and right corner part upper end face molds 25, and the lower floor plate end face molds 26 are jacked down as indicated by the downward arrows, and the upper floor slab end face molds Separate from the frame 13.

  Next, as shown in FIG. 3 (b), the left and right jacks 21 for adjusting the arrangement of the left and right are mutually adjusted in height so that the upper floor slab end face mold 13 is matched to the transverse gradient of the upper floor slab, and the mold rotating core The rod 22 is rotated by a predetermined angle around the center. Subsequently, the left and right web end face molds 24 are temporarily fixed at predetermined positions to the upper floor slab end face mold 13.

  Next, as shown in FIG. 4A, the left and right corner part lower end surface molds 27 are separated from the lower floor slab end surface molds 26 by a jack-down operation indicated by a downward arrow.

  Next, as shown in FIG. 4 (b), the left and right corner part upper end surface formwork 25 is newly attached to the upper floor slab end face formwork 13. Further, the inclination of the lower floor slab end face mold 26 is adjusted according to the slope of the upper floor slab end face mold 13 by the jack up and jack down operations indicated by the left upward arrow and the right downward arrow.

  Next, as shown in FIG. 5A, the web end face mold 24 is set on the left and right corner part upper face mold 25. Further, the corner part lower end surface mold frame 27 is attached to the lower floor plate end surface mold frame 26, and further, the lower floor plate end surface mold frame 26 is attached to the web end surface mold frame 24 by a jack-up operation indicated by an upward arrow.

  By the series of operations, as shown in FIG. 5B, the main body of the end surface formwork of the curved road surface type box girder is configured in accordance with the inclination of the upper floor slab end face formwork 13 inclined to a predetermined slope. The left and right web end face formwork 24, the left and right corner part upper end face formwork 25, the lower floor slab end face formwork 26, and the left and right corner part lower end face formwork 27 can be smoothly arranged. A curved road surface-corresponding box girder 11 shown in FIG. 1B can be smoothly formed over the entire mold including the mold.

  That is, in the mold apparatus 12, when the arrangement of the both-ends formwork of the box girder newly provided as described above is ready, the upper flat outer formplate for constructing the upper surface of the upper floor slab 2, the lower Lower flat outer mold plate for constructing the lower surface of the floor slab 3, both flat outer mold plates for constructing both outer surfaces of the web 4, the inner mold frame for constructing the ceiling surface, both inner surfaces, and inner bottom surface of the hollow portion 5 ( Both of them are not shown) and are arranged and supported at predetermined positions, and concrete is cast inside to construct a box girder 11b.

  According to the formwork apparatus of the present invention, the upper floor slab end formwork (bulk head) is rotated, so that the web and lower floor slab (block body) are not rotated, and the upper floor slab is compatible with curved road surfaces having a cross-sectional gradient. Mold box girder can be easily manufactured in the factory.

In the present invention, the curved road surface type box girder utilizing the technical idea of claim 1 can be applied to a box girder having an inclined web. In addition, it is within the scope of the present invention to appropriately change the design of the configuration shown in each embodiment.

(A) is an end view of a standard type of box girder manufactured by the formwork apparatus according to the present invention, and (b) is an upper floor slab of the box girder manufactured by the formwork apparatus according to the present invention. FIG. 6C is an end surface explanatory view showing a shift (non-identical shape) of both end surfaces in another example of a curved road surface corresponding type box girder. It is front explanatory drawing which shows the arrangement | positioning aspect of the box-girder end surface formwork at the time of the crossing gradient of a box girder being constant (at the time of an upper floor slab end surface formwork (bulkhead) horizontal). (A), (b) is a first step showing the replacement of the box girder body end face formwork and the displacement form when rotating the upper floor end face formwork (bulk head) at the time of changing the cross gradient of the box girder. It is explanatory drawing of a 2nd process. (A), (b) is a third step showing the replacement of the box girder body end face formwork and the displacement form when rotating the upper floor end face formwork (bulk head) at the time of changing the cross gradient of the box girder. It is explanatory drawing of a 4th process. (A), (b) is a fifth step showing the replacement of the box girder body end face formwork and the displacement form when rotating the upper floor slab end face formwork (bulk head) at the time of changing the cross gradient of the box girder. It is explanatory drawing of a 6th process. It is a front view of a formwork apparatus. It is a top view of a formwork apparatus. It is a side view of a formwork apparatus. It is an enlarged view of the adjustment mechanism of the upper floor slab end face formwork (bulk head) and the gradient adjusting jack. (A), (b) is the right view of FIG. 9 at the time of expansion | extension of a jack for gradient adjustment, and shrinkage | contraction. 10A is a detailed cross-sectional view of FIG. 10A, FIG. 10B is a cross-sectional view along the line BB in FIG. 10A, and FIG. It is explanatory drawing which shows the rotational deformation of an end surface formwork. (A) is an end view of a standard box girder manufactured by a conventional formwork device, and (b) is an end face showing a deviation between the end faces of the box girder when the box girder of FIG. It is explanatory drawing. (A) is the top view which shows a part of curve road, (b) is the perspective view which looked at the curve road from diagonally downward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Box girder 1a Box girder 2 Upper floor slab 3 Lower floor slab 4 Web 5 Hollow part 6 Box girder main part 7 Curve road 11 Box girder 11b Curve corresponding type box girder end surface 12 Formwork device 13 Upper floor slab end face formwork 14 Form fixing Frame 15 Upper beam for mold support 16 Lower frame for mold support 17 Upper horizontal frame 18 Post 19 Upper horizontal arm 20 Support pin 21 Jack for adjusting gradient 22 Core rod for mold rotation 24 Web end surface mold frame 25 Lower end surface of corner Formwork 26 Lower floor plate end face formwork 27 Corner part lower end face formwork 28 Formwork holding material 29 Inner formwork

Claims (3)

  It is already installed in a curved road surface type box girder that consists of upper and lower floor slabs and webs that connect the upper and lower floor slabs, and twists both ends of the box girder in the direction of the bridge axis to form a short line method. The intersections of the upper floor plate end surface and the web end surface molded with the box girder end surface as a mold on one end side are defined as (A) and (B), and the intersection points of the lower floor plate end surface and the web end surface are defined as (C) and (D). With respect to the box girder one end surface shape, the box girder other end surface shape is twisted by a predetermined angle with the center of the upper floor slab end surface as the rotation core (O), and the lower floor slab end surface is displaced in parallel with the upper floor slab end surface. Thus, the intersection points (A-1), (B-1) where the web end face, the lower floor end face, and the upper floor end face are displaced relative to the intersection points (A), (B), (C), (D). ), (C-1), and (D-1) so that they cross each other. Are formed on, over the other end surface from the box girder end face, curve road corresponding type, characterized in that the box girder profile are formed continuously box girder.   2. A formwork apparatus using a short line method for manufacturing a curved road surface-compatible box girder according to claim 1, comprising an outer mold frame, an inner mold frame, and both end surface mold frames, wherein the one-end surface mold frame comprises an end surface of an existing box girder. The other end surface formwork arranged opposite to the upper floor plate is composed of an upper floor plate end surface mold frame and a plurality of box girder body end surface mold frames, and the upper floor plate end surface mold frame is provided on the frame of the mold apparatus. It is arranged in parallel with the upper beam for formwork support, and the center of the upper floor slab end face formwork is pivotally supported by a support shaft protruding laterally from the upper beam for formwork support, and Both end portions are connected to a telescopic operation shaft of a gradient adjusting jack provided on the gantry, and are provided rotatably with the support shaft as a rotation core. The plurality of box girder body end face molds are upper floor slab end face molds. A formwork apparatus characterized by being provided so as to be able to be displaced and arranged corresponding to the rotational displacement of the frame. A method for manufacturing a curved road surface type box girder according to claim 1 by a short line method of the following process.
(First step) In the state where the new box girder is completed with the axial end of the existing box girder constructed in the previous process as a part of the mold, the outer mold is allowed to escape outward and the box girder The inner mold forming the hollow portion is moved in the axial direction to be removed.
(Second process) The existing box girder is completed by separating the end faces of the existing box girder and the new box girder in the axial direction and moving the box girder to the next process in the axial direction sequentially. And the new box girder is moved to a position to be the other end face form frame forming the end face of the box girder to be manufactured in the next process.
(Third step) A reinforcing bar unit similar in shape to a box girder is placed at a predetermined position.
(Fourth step) The inner mold is moved in the axial direction and moved to a predetermined position for a new box girder to be manufactured next.
(Fifth step) Rotation of the upper floor plate end surface mold on the other end surface arranged in parallel with the one end surface mold formed by the end surface of the existing box girder on the axis of the upper floor plate end surface mold Inclined by a predetermined angle around the core, and corresponding to the inclined upper floor slab end face mold, the web girder body part end face mold, the web end face mold, the lower floor slab end face mold, and the corner The upper and lower end surface formwork is rearranged to a predetermined part, and concrete is placed in the formwork including the end face formwork, the outer formwork and the inner formwork.
(Sixth step) A box girder is completed.

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