JPS6157702A - Construction of continuous floor panel between ridge stands by single steel beam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention is directed to a multi-span simple steel girder, which eliminates the intermediate expansion and contraction device in the bridge to form one continuous composite deck between the abutments. This paper relates to a construction method for continuous deck slabs between abutments using simple steel girders.

``Prior art'' Conventionally, in the case of elevated roads that form the road surface for vehicles to travel on, if this was a simple girder, it would be one girder, and as shown in Figure 4, five
The main girder 3 delivered by the piers 2 constructed in sections at regular intervals between the tower bases 1. Between the adjacent concrete slabs 4 and 4 being constructed,
In other words, the expansion and contraction device 5 is provided for each span. This is to absorb the expansion and contraction of the steel girder due to temperature changes.

``Problems to be Solved by the Invention'' In such a so-called multi-span simple steel girder, the expansion and contraction device 5 is provided for each span as described above.
These expansion and contraction devices 5 affect the running performance of the vehicle and cause noise generation, and in the past, these expansion and contraction devices have often been damaged, causing problems in the maintenance and management of bridges. .

Therefore, the present invention seeks to provide a method for constructing continuous deck slabs between tower platforms using multi-span simple steel girders, which can improve vehicle running performance, prevent noise, reduce construction costs, and reduce maintenance. It is something.

"Means for solving the problem" In the case of non-invention, between the elms, there is a
In the method for constructing a steel girder erect with piers as described above, the main girder is constructed as a simple girder, and a precast composite deck slab of concrete i equipped with a steel plate #bottom formwork having a welding allowance for connection is placed on top of the main girder as a simple girder. After sequentially laying and welding the bottom forms of each of these slabs together, concrete IJ is cast in the joints between each slab to form one continuous composite slab between the joints. This is how it was done.

When installing each precast composite deck slab, the deck slab placed on the scaffolding should be placed in one piece so that it overlaps both of the main girders adjacent to each other in the direction of the bridge axis. It is preferable to lay it in such a form as to

``Example'' The examples shown in Figures 1 to 3 show construction examples for a four-span bridge with three piers 2 between the gantry 1.1, and as is clear from these figures. The deck 10 is formed as a continuous composite deck over multiple spans, that is, over four spans, and the main girder 3 is constructed as a simple girder similar to the conventional example shown in FIG.

Next, an example of the construction method for the synthetic floor slab ■0 will be described.

For example, as shown in FIG. 2, a large number of reinforcing steel materials such as 7 bells [2, main bars 13, distribution bars I4, etc.] are arranged on a steel plate section formwork 11 that also serves as a strength member, and concrete L5? A so-called concrete precast composite floor slab 1 (1') is prepared and formed by forming a connection bath contact LLa & n) in a form that wraps around the area formwork 11. It is sequentially laid on the main girder 3, and the welding margins Lla of the section forms 1.1 in each of these precast composite deck slabs lO' are brought into bath contact α.At this time, each precast composite floor slab lO ′, that is, pier 2
The composite deck slab tσ located above is laid so as to overlap (straddle) both of the main girders 3.3 adjacent to each other in the bridge axis direction, and the section formwork 11 of this composite deck slab 10' is 84
It is fixed with bolts 16 to the respective upper flanges 3a, 3a of both main girders 3, 3 adjacent to each other in the IllII direction.

Next, joint concrete 17 is placed at the joints for connecting the precast synthetic floor slabs 10' that have been laid, and is allowed to harden. Furthermore, a paving layer 8 of asphalt or the like is placed on each synthetic floor slab 10'. When this is done, one continuous composite deck IO is formed in four spans between the gantry 1.1 as shown in FIG.

The synthetic deck lO formed in this way is composed of the abutment 1. L
Since there is no expansion/contraction device between the floor slabs and the floor slab is uniform and continuous, the causes of various problems caused by the presence of expansion/contraction devices in the past are completely eliminated.

By the way, when implementing the present invention, the main girder is designed as a simple girder, but in order to make the deck slab continuous over multiple spans.

A slight negative bending moment is generated on the intermediate fulcrum P.

However, can this negative bending moment be applied to a strength member? Is it an action to minimize the tensile force in the axial direction that is borne by the bottom formwork 11 and acts on the concrete 15? Demonstrate.

Here, if the negative bending moment mentioned above is large,
As clearly shown in Fig. 2, among the bottom formwork IT portion of the precast composite deck slab 10', the
．． It is desirable that the portion that straddles the third portion be formed into a thick portion ttb that is sufficiently thicker than the other portions.

Further, if necessary, as shown in FIG.
On top of b, the concrete layer 5 on the lower formwork 11 and a pair of steel partition plates 19.1'l dividing it into two in the axial direction are fixed, respectively, and the inner partition plates 19.19 are fitted together. It is also preferable to take measures to provide a pair of thin partition members 20.20 that divide the paving device 8 into two in the same axial direction. In the figure, 19a is the anchor reinforcement of the partition plate 19.

If the above-mentioned measures are taken, the thick portion 11. The effect of l) makes it possible to reliably prevent cracks in the concrete 15 on the intermediate supporting point P in the bridge axis direction. In particular, in the configuration shown in FIG.
5. And the paving place 8 is the partition plate 19. The thick wall portion 11 is edged on the pier 2 by the partition material 20. Since the structure is continuous only at section b, the tensile force in the axial direction that acts on the slab itself due to various causes such as earthquakes does not act on the concrete IJ-to layer 15 or the pavement layer 8, etc., and is applied to the thick wall section. It acts only on the tlb portion, and as a result, the crack prevention effect described above becomes even more reliable.

In addition, according to the method of the example, the drop beam main body and the substructure become one continuous structure, so horizontal forces due to earthquakes etc. are taken into consideration.
Therefore, for example, as shown in the illustrated example (i.e., one of the main girders 3, 3 on the pier 2 is fixed to the pier 2 and the other is movable, or the horizontal force is taken at one place, It is desirable to take measures such as making everything else movable based on the results of a three-dimensional analysis that also takes into account weather conditions at the construction site.

``Effects of the Invention'' As explained above, according to the present invention, precast composite deck slabs are connected in series to form a continuous uniform composite deck slab over multiple spans, so that it is possible to By eliminating the expansion and contraction devices for each span that were required for steel girder removal, it is possible to improve workability and reduce costs.Moreover, by removing the compression devices in this way, it is possible to improve the running speed of vehicles. It has excellent advantages such as improved performance, prevention of rusting noise, etc., and is also preferable from the viewpoint of bridge maintenance philosophy.

[Brief explanation of the drawing]

Figures 1 to 3 show examples of non-invention.
The figure is a schematic side view, Figure 2 is an enlarged view of the part indicated by IN in Figure 1, Figure 3 is an enlarged view similar to Figure 2 showing another embodiment,
FIG. 4 is a schematic side view showing a conventional example. 1... Loading platform, 2... Pier, 3°... Main girder, 3a°.
・Top flange, 10... Floor slab, lσ... Precast synthetic floor slab, 11... Taste part type 伜, tta-... Bath welding type, ttb... Thick part, 15... Concrete (concrete layer), 17... joint concrete, 19...
・Steel partition plate.

Claims (1)

[Claims] (1.) A method of constructing a steel girder bridge having one or more piers for supporting a main girder between the abutments, wherein the main girder is constructed as a simple girder, and the main girder is constructed as a simple girder; , concrete precast composite deck slabs each having a steel plate bottom formwork with a welding allowance for connection are sequentially installed, and after the bottom forms of these precast composite deck slabs are welded together, the spaces between each precast composite deck slab are A method for constructing continuous deck slabs between abutments using multi-span simple steel girders, characterized by pouring concrete into the joints of the abutments to form one continuous composite deck slab between the abutments. (2.) A part of each precast composite floor slab,
A patent claim characterized in that the precast composite slab is laid so as to overlap both main girders adjacent in the axial direction of the bridge, and the bottom formwork of this precast composite deck is fixed to both of the main girders adjacent in the bridge axial direction. The construction method described in item 1 of the scope. (3.) The bottom formwork of the precast composite deck, which is laid overlapping both of the main girders adjacent to each other in the bridge axis direction, is made thicker at least in the part that spans between the adjacent main girders than in other parts. 3. The construction method according to claim 2, wherein the thick wall portion is provided with a partition plate that divides the concrete layer on the bottom formwork into two in the bridge axis direction.