JP2018021403A - Floor slab replacement method for steel composite girder, and pc floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor slab replacement method for a steel composite girder that is less likely to cause interference between a PC steel material of the PC floor slab to be replaced when replacing the floor slab of the steel composite girder, at the same time curtailing duration of the floor slab replacement work.SOLUTION: A floor slab replacement method for a steel composite girder is for replacing an existing concrete floor slab with a PC floor slab 1, the existing concrete floor slab being a part of a steel composite girder that integrates a steel girder G1 with the concrete floor slab. The floor slab replacement method includes: a floor slab removal step for dismantling and removing the existing concrete floor slab; a PC floor slab installation step for installing a PC floor slab 1 on the steel girder G1, the PC floor slab having a stud hole (a cotter 12) for housing a stud dowel SJ and joining with the steel girder G1 formed between a PC steel material 11 and the other PC steel material 11, and for each width of a stud in a bridge axial direction; and a stud erection step for erecting a stud dowel SJ' on a top surface of the steel girder G1, in a stud hole (a cotter 12) of the PC floor slab 1 installed in the PC floor slab installation step.SELECTED DRAWING: Figure 7

Description

  TECHNICAL FIELD The present invention relates to a steel composite girder floor slab replacement method and a PC floor slab, and more particularly, to a steel composite girder floor slab replacement method for replacing a steel composite girder floor slab with a PC floor slab and a new PC floor slab thereof. .

  Conventionally, in such a steel composite girder floor slab replacement method, a steel composite girder floor slab is replaced with a precast PC floor slab or the like. For example, in Patent Document 1, when replacing a composite slab floor slab with a precast floor slab, remove the existing composite girder floor slab and synthesize the precast floor slab before synthesizing the precast floor slab. The main girder is placed with the box opening formed on the precast floor slab positioned on the upper flange of the main girder in order to prevent the main girder from falling down and to eliminate the disadvantages of existing prevention measures. Set the distance between the boxed parts in the direction to the distance between the fixed points, temporarily fix the precast floor slab and main girder at the boxed part, and release the fixation after the precast floor slab is installed and place concrete in the boxed part The main girder lateral buckling prevention construction method is disclosed (see claim 1 of Patent Document 1, paragraphs [0008] to [0010] of the specification, FIG. 1 of FIG. 1, FIG. 9 and the like).

  However, when the steel composite girder floor slab is replaced with the precast PC floor slab in the steel composite girder floor slab replacement method, as in the main girder lateral buckling prevention method described in Patent Document 1, the steel girder Since it is necessary to synthesize and synthesize the PC floor slab, many stud gibels connecting the steel girder and the PC floor slab have been required. For this reason, as a result, the hole of the PC floor slab for the stud increases, and as shown in FIG. 9, there is a problem that it is difficult to dispose the PC steel material that gives prestress.

  Further, in order to solve such a problem, an invention is known in which the stud gibber group is installed at a larger interval by increasing the shear strength of the stud dowels and the number of stud dowels arranged in the bridge axis direction is reduced. ing. For example, in Patent Document 2, in the joint structure of a steel main girder of a steel composite girder bridge and a precast PC floor slab, an edge of a plurality of high-strength stud gibbles erected on the upper flange of the steel main girder Spiral bars made of coiled springs are arranged at the base of two high-strength stud gibels with a short distance, and a stud-jivel unit consisting of these two spiral bars and a plurality of high-strength stud gibels is precast PC. The steel main girder and the precast which join the steel main girder and the precast PC floor slab by inserting and fixing the mortar in the stud diver hole after passing through the stud gibber hole drilled at the position where the PC steel material of the floor slab does not exist A joining structure of PC floor slabs is disclosed (see claim 1 of Patent Document 1, paragraphs [0012] to [0014] of the specification, FIG. 1 of the drawings, etc.).

  However, in the joining structure of the steel main girder and the precast PC floor slab described in Patent Document 2, in order to increase the shear strength of the stud gibber, a spiral bar must be arranged at the root of the high-strength stud gibber. There is a problem that it takes time to install the streaks, and the working time is extended and the working cost is increased. In addition, there is a problem in that the production cost increases because a high-strength stud dowel or a spiral streak is disposed.

JP-A-8-218327 JP 2005-256430 A

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is to interfere with the PC steel material of the PC floor slab to be replaced when the steel slab girder is replaced with the stud. An object of the present invention is to provide a steel composite girder floor slab replacement method that is less prone to fear and can reduce the work time of floor slab replacement work.

  The steel composite girder floor slab replacement method according to the first aspect of the present invention is a steel composite girder floor slab replacement in which an existing concrete floor slab of a steel composite girder integrated with a steel girder and a concrete floor slab is replaced with a PC floor slab. A floor slab removal step for dismantling and removing the existing concrete floor slab, and a stud hole for accommodating the stud gibber and synthesizing with the steel girder between the PC steel and another PC steel, and In the bridge axis direction, a PC floor slab installation step in which a plurality of PC floor slabs formed for each stud width are installed on the steel girder, and the PC floor slab installed in the PC floor slab installation step In the stud hole, a stud erecting step of erecting a stud diver on the upper surface of the steel beam is provided.

  According to a second aspect of the present invention, there is provided a steel composite girder floor slab replacement method according to the first invention, wherein, in the stud erecting step, the stud gibber stands on the upper surface of the steel girder by bolting the stud girdle to the steel girder. It is characterized by providing.

  The steel composite girder floor slab replacement method according to the third invention is characterized in that, in the second invention, in the stud erecting step, a stud gibber is bolted to the steel girder using a locking nut.

  According to the PC composite slab of the steel composite girder according to the fourth aspect of the invention, the prestress is applied by the PC steel material, and the PC composite slab of the steel composite girder that is integrated and installed on the steel girder with the stud gibber, Stud holes for accommodating the stud gibber and synthesizing with the steel girders are individually provided between the PC steel members for each stud.

  According to the first to third inventions, the possibility of interference between the PC steel material of the PC floor slab and the stud to be replaced when the steel composite girder is replaced is reduced. For this reason, the risk of damaging the PC steel material is reduced, and the work time of the floor slab replacement work can be shortened. Therefore, the construction cost of the steel composite girder floor slab replacement work can be reduced.

  In particular, according to the second invention, since the stud gibel is bolted to the steel beam, it is not necessary to perform the stud welding impact test, and it is possible to reduce the time for re-welding based on the test time and the result. For this reason, the work time of the floor slab replacement work can be shortened and the construction cost of the floor slab replacement work can be reduced.

  In particular, according to the third aspect of the present invention, since the stud gibel is bolted to the steel girder using the locking nut, the bolt is less likely to loosen due to vibration, and the durability is improved.

  According to the fourth aspect of the invention, the possibility of interference between the PC steel material of the PC floor slab installed on the steel composite girder and the stud is reduced. For this reason, the risk of damaging the PC steel material is reduced, and the work time of the floor slab installation work can be shortened. Therefore, it is possible to reduce the construction cost for installing the PC slab of the steel composite girder.

It is a top view which shows PC floor slab of the steel synthetic girder which concerns on 1st Embodiment of this invention. It is a top view which shows PC floor slab of the steel synthetic girder which concerns on 2nd Embodiment of this invention. It is a flowchart which shows each process of the floor slab replacement construction method which concerns on embodiment of this invention. It is a vertical sectional view which shows the existing steel composite girder before performing replacement work by the same floor slab replacement method. It is process explanatory drawing which shows the floor slab removal process of a floor slab replacement construction method same as the above. It is process explanatory drawing which shows the PC floor slab installation process of a floor slab replacement construction method same as the above. It is process explanatory drawing which shows the stud standing process of a floor slab replacement construction method same as the above. It is process explanatory drawing which shows the filler filling process of a floor slab replacement method same as the above. It is a top view which shows the problem of the conventional PC floor slab.

  Hereinafter, an embodiment for carrying out a floor slab replacement method according to the present invention will be described in detail with reference to the drawings.

  First, with reference to FIG. 1 and FIG. 2, a new PC floor slab that is replaced from an existing concrete floor slab by the floor slab replacement method according to the embodiment of the present invention will be described. FIG. 1 is a plan view showing a PC slab of a steel composite girder according to a first embodiment of the present invention.

[First Embodiment]
The steel composite girder PC floor slab 1 according to the first embodiment is composed of a floor slab body 10 made of reinforced concrete having a rectangular thick plate shape, a PC steel material 11 inserted into the floor slab body 10, and the like. 11 is a pre-tensioned precast PC floor slab pre-stressed by No. 11. Therefore, the PC floor slab 1 is a large-sized precast floor slab that has a large span in the longitudinal direction along the PC steel material 11 due to the action of prestress.

  However, it goes without saying that the PC floor slab according to the present invention may be a precast PC floor slab using both pre-tension and post-tension, or a post-tension precast PC floor slab. In short, if the PC floor slab according to the present invention is a steel composite girder PC floor slab that is prestressed by PC steel and is integrated with a stud gibber on the steel girder, the present invention is applied. Can do.

  Further, as shown in FIG. 1, the floor slab body 10 of the PC composite slab 1 of the steel composite girder according to the first embodiment is provided with a stud gibber (headed) erected on the upper surface of the upper flange G10 of the steel girder G1. Stud) A cotter 12, which is a stud hole for accommodating the SJ and synthesizing it with the steel girder G1, is provided individually for each stud gibber SJ. The steel girder G1 will be described later.

  The cotter 12 is a cylindrical hole having a diameter that accommodates the stud dowels SJ one by one and is separated from the stud dowels SJ by a predetermined distance. The cotter 12 is filled with a filler such as a non-shrink mortar, and transmits bending stress and shear stress acting on the PC floor slab 1 to the steel girder G1 via the stud gibber SJ, and is integrated with the steel girder G1. It has a function to make it.

  As described above, according to the PC composite slab 1 of the steel composite girder according to the first embodiment, the cotter 12 of the PC slab 1 is individually provided corresponding to each stud gibber SJ to reduce the diameter per piece. be able to. Thereby, the cotter 12 can be arrange | positioned, without reducing the number of stud dowels and increasing the shear force borne for every stud dowel. For this reason, it is possible to arrange the cotter 12 while ensuring the necessary cover thickness between the PC steel materials 11 without reducing the number of the PC steel materials 11.

  Therefore, according to the PC floor slab 1 of the steel composite girder according to the first embodiment, the PC steel material is not exposed in the cotter as shown in FIG. The risk of damaging the PC steel material 11 is reduced. For this reason, the safety can be improved, and the work efficiency can be improved by omitting the trouble of standing the stud while safely considering so as not to be damaged.

[Second Embodiment]
Next, a PC composite slab 1 ′ of a steel composite girder according to a second embodiment of the present invention will be described with reference to FIG. The difference between the steel composite girder PC floor slab 1 'according to the present embodiment and the steel composite girder PC floor slab 1 according to the first embodiment described above is only the shape of the cotter. The same components are denoted by the same reference numerals, and description thereof is omitted. FIG. 2 is a plan view showing a PC slab of a steel composite girder according to a second embodiment of the present invention.

  As shown in FIG. 2, the steel composite girder PC floor slab 1 ′ according to the second embodiment is made of rectangular thick plate-shaped reinforced concrete, like the steel composite girder PC floor slab 1 according to the first embodiment. This is a pre-tensioned precast PC floor slab composed of a floor slab body 10 ′ and a PC steel material 11 inserted into the floor slab body 10 ′ and prestressed by the PC steel material 11.

  Further, as shown in FIG. 2, the floor slab body 10 'of the PC composite slab 1' of the steel composite girder according to the second embodiment is provided with a stud gibber SJ erected on the upper surface of the upper flange G10 of the steel girder G1. Are provided, and a cotter 12 'is provided for synthesizing the steel girder G1 two by two.

  The cotter 12 'is a hole having a long hole shape along the direction X perpendicular to the bridge axis, and is large enough to accommodate two stud dowels SJ. Further, the cotter 12 'has a width corresponding to one stud dowel SJ in the bridge axis direction Y. For this reason, similarly to the PC floor slab 1 of the steel composite girder according to the first embodiment, the cotter 12 ′ can be disposed between the PC steel materials 11 without reducing the number of the PC steel materials 11.

  Thus, according to the PC floor slab 1 ′ of the steel composite girder according to the second embodiment, in addition to the effects of the PC floor slab 1 described above, without reducing the number of the stud gibber SJ and the PC steel material 11, The number of cotters 12 'can be reduced. For this reason, the work time for filling the cotter 12 'with the filler can be reduced and the work time can be shortened.

[Floor replacement method]
Next, a steel composite girder floor slab replacement method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart showing each step of the steel composite girder floor slab replacement method according to the embodiment of the present invention. As shown in FIG. 3, the floor slab replacement method according to the present embodiment performs the steps (1) to (4), and the steel composite girder K1 in which the steel girder and the concrete floor slab are integrated. In this method, the existing concrete floor slab SC is replaced with a PC floor slab 1 (1 ′) to obtain a steel composite girder K1 ′. Next, each process of the floor slab replacement method according to the embodiment will be described.

  First, an existing steel composite girder before replacement work will be briefly described. FIG. 4 is a vertical cross-sectional view showing a state where the existing steel composite girder K1 before being replaced by the floor slab replacement method according to the present embodiment is cut along a vertical cross section perpendicular to the bridge axis direction Y. The existing steel composite girder K1 shown in the figure is composed mainly of a steel girder G1 which is a main girder and an existing concrete floor slab CS made of reinforced concrete, and is made of steel by a stud gibber SJ which is fused on the upper surface of the steel girder G1. A steel composite girder in which the girder G1 and the concrete floor slab CS are integrated.

  This steel girder G1 is an I-shaped cross-section steel plate assembled by welding thick steel plates having predetermined dimensions, and includes an upper flange G10, a lower flange G11, and a web G12 connecting these. Since this upper flange G10 is calculated as an integral part of the existing concrete floor slab CS, it is generally smaller in width than the lower flange G11.

(1) Floor slab removal process First, in the floor slab replacement method according to this embodiment, a floor slab removal process is performed in which the existing concrete floor slab CS is disassembled and removed together with the existing stud gibber SJ. FIG. 5 is a process explanatory view showing the (1) floor slab removal process of the floor slab replacement method according to the present embodiment, and shows a vertical section similar to FIG.

  Specifically, in this process, the concrete around the existing stud dowel SJ is scraped off by using a drilling machine such as a call pick hammer or a hydraulic breaker, The gibber SJ is cut from the root, and the steel girder G1 and the existing concrete floor slab CS are separated. Then, the existing concrete floor slab CS is cut / divided into a size capable of being lifted using a diamond cutter, a punching machine, or the like, and then removed and carried out.

(2) PC floor slab installation process Next, in the floor slab replacement method according to this embodiment, as shown in FIGS. 6 and 3, the PC floor slab 1 according to the first embodiment described above is replaced with a steel girder G1. A PC floor slab installation process is carried out for mounting and mounting at a predetermined position. FIG. 6 is a process explanatory view showing a PC floor slab installation process of the floor slab replacement method according to the present embodiment, and is shown by a vertical cross section similar to FIG. Specifically, in this step, the new PC floor slab 1 is installed over a predetermined position of the steel beam G1 using a lifting device such as a rough terrain crane.

  Further, as described above, the PC floor slab 1 installed in this step is a pre-tensioned precast PC floor slab pre-stressed. Therefore, the PC floor slab 1 can be a large-sized precast floor slab having a large span in the longitudinal direction along the PC steel material due to the action of prestress. For this reason, the working time of this process can be shortened by reducing the frequency | count of lifting / suspending of the PC floor slab 1 mounted in this process.

  In this process, it goes without saying that the PC floor slab 1 ′ according to the second embodiment may be installed instead of the PC floor slab 1. In that case, the number of cotters 12 'of the PC floor slab 1' is halved from the number of cotters 12 of the PC floor slab 1 (see FIGS. 1 and 2). For this reason, in the post-filler filling step, it is possible to reduce the work time for filling the cotter 12 ′ with the filler and shorten the work time.

(3) Stud Standing Step Next, in the floor slab replacement method according to this embodiment, as shown in FIGS. 7 and 3, a stud stand for standing a new stud gibber SJ ′ on the upper surface of the steel girder G1. Perform the installation process. FIG. 7 is a process explanatory view showing a stud standing process of the floor slab replacement method according to the present embodiment, and shows an enlarged part near the stud gibber.

  Specifically, in this process, using a drilling machine such as a hard drill for shape steel, the stud gibber SJ ′ is centered on the center position of the cotter 12 of the PC floor slab 1 placed in the previous process. A bolt hole h1 through which the constituent stud bolt SB is inserted is drilled in the upper flange G10 of the steel beam G1. Then, the stud bolt SB is bolted to the upper flange G10 using the locking nut N1, and the stud gibber SJ 'is erected on the upper surface of the steel beam G1.

  As shown in the nut cross section of the enlarged view of FIG. 7, this locking nut N1 is a nut having a locking prevention mechanism utilizing the principle of a wedge such as a hard lock (registered trademark) nut manufactured by Hard Rock Industry Co., Ltd. It is. Thus, in this step, the stud gibber SJ is bolted to the upper flange G10 of the steel girder G1 using the locking nut N1, so that the bolt is less likely to loosen due to vibration and durability is improved. It is also possible to use a nut and a nut combination that prevents a bolt joint from loosening by fitting with a resin ring, such as a nylon nut manufactured by Lock Fastener Co., Ltd., or other bolts and nuts having other loosening prevention mechanisms. Moreover, it is good also as a double nut simply.

  In this step, as described above, in the PC floor slab 1 and the PC floor slab 1 ', the PC steel material 11 is not exposed in the cotter 12 (cotter 12'). For this reason, in this process, even when the newly installed stud gibber SJ 'is erected, there is less risk of damaging the PC steel material 11 to which a strong prestressing tension is applied. For this reason, the safety can be improved, and the work efficiency can be improved by eliminating the trouble of standing the stud while safely considering so as not to be damaged.

  As described above, in this step, the stud dowel SJ 'is erected on the upper surface of the steel girder G1 not by stud welding as usual, but by dry-type bolting. For this reason, a post-process can be started immediately after the end of this process, and the working time can be shortened. In addition, the stud welding impact test is not required as compared with the case where the stud gibble is erected by stud welding, and the time for re-welding can be reduced by receiving the test time and the result. For this reason, the work time of the floor slab replacement work can be further shortened and the construction cost of the floor slab replacement work can be reduced.

(4) Filler Filling Step Next, in the floor slab replacement method according to this embodiment, as shown in FIGS. 8 and 3, a filler D such as a non-shrink mortar is placed in the cotter 12 of the PC floor slab 1. A filling material filling process is performed.

  As the filler D used in this step, in addition to non-shrink mortar, a hardened cement cured by a hydration reaction such as general concrete or mortar can be used. However, since the gap between the cotter 12 (12 ') and the stud gibber SJ' is narrow, a mortar having no coarse aggregate is preferable, and a non-shrinkable mortar having very little drying shrinkage upon curing is more preferable. If cost is not taken into consideration, it is also possible to use a resin or the like as the filler.

  After performing this process, as shown in FIG. 3, the curing period until the filler is hardened is taken, and other necessary operations such as asphalt pavement are performed on the PC floor slab 1 in this embodiment. The floor slab replacement work (updating work of the steel composite girder K1 to the steel composite girder K1 ′) of the floor slab replacement method according to is completed.

  According to the floor slab replacement method according to the present embodiment described above, there is less possibility of interference between the PC steel material 11 of the PC floor slab 1 to be replaced when the steel composite girder floor slab is replaced and the stud gibber SJ '. For this reason, the risk of damaging the PC steel material 11 is reduced, and the work time of the floor slab replacement work can be shortened. Therefore, the construction cost of the floor slab replacement work for the steel composite girder K1 can be reduced.

  Further, according to the floor slab replacement method according to the present embodiment, the stud gibber SJ 'is bolted to the steel girder G1, so that it is not necessary to perform the stud welding impact test, and the welding is performed after receiving the test time and result. Time can be saved. For this reason, the work time of the floor slab replacement work can be shortened and the construction cost of the floor slab replacement work can be reduced.

  As described above, the steel composite girder PC floor slab according to the embodiment of the present invention and the steel composite girder floor slab replacement method according to the embodiment of the present invention have been described in detail. However, the embodiment of the present invention is merely shown as a specific embodiment, and the technical scope of the present invention should not be construed as being limited thereto.

1, 1 ': PC floor slab 10, 10': Floor slab body 11: PC steel 12, 12 ': Cotter (stud hole)
D: Filler SJ ': (Newly installed) Stud Giber SB: Stud Bolt (Stud Giber)
N1: Locking nut (stud gibber)
K1, K1 ': Steel composite girder G1: Steel girder (main girder)
G10: Upper flange h1: Bolt hole G11: Lower flange G12: Web CS: Existing concrete floor slab SJ: (Existing) stud gibber

Claims (4)

A steel composite girder slab replacement method that replaces an existing concrete slab of a steel composite girder in which a steel girder and a concrete floor slab are integrated with a PC floor slab,
A floor slab removal step of dismantling and removing the existing concrete floor slab;
The PC, in which a stud hole for accommodating a stud gibel and synthesizing with the steel beam is formed between a PC steel material and another PC steel material, and a plurality of studs are formed for each stud width in the bridge axis direction. PC floor slab installation process for installing the floor slab on the steel beam;
A floor of a steel composite girder, comprising: a stud erecting step of erecting a stud gibel on an upper surface of the steel girder in the stud hole of the PC floor slab installed in the PC floor slab installation step Plate replacement method. 2. The steel composite girder floor slab replacement according to claim 1, wherein, in the stud erecting step, the stud gbell is erected on the upper surface of the steel girder by bolting a stud giber to the steel girder. Construction method. 3. The steel composite girder floor slab replacement method according to claim 2, wherein, in the stud erecting step, a stud gibel is bolted to the steel girder using a locking nut. A PC floor slab of steel composite girders that is prestressed by PC steel and is integrated and installed on the steel girders with stud gibbles,
A PC floor slab for steel composite girders, wherein stud studs for accommodating the stud gibbles and synthesizing with the steel girders are provided individually for each stud between the PC steel materials.

Images