JPS584005A - Construction of connected beam by prestressed 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 The present invention relates to a method for constructing a prestressed steel girder when constructing a bridge using a prestressed steel girder commonly referred to as a prestressed steel girder, and particularly to a method for constructing a connecting girder using the prestressed steel girder. As a construction girder for a 00 bridge, a forward deflection load is applied to the steel girder in advance, ψ is placed on the lower 7 lunges on the tensile side, and concrete is poured to cover the lower 7 lunges. A prestressed steel girder, commonly called a pre-beam, is already known (Special Publication No. 18N -too Koda).

A girder in which such a prestressed steel girder is erected on site and then web concrete and slab concrete are placed to completely cover the steel girder with concrete is called a pre-beam composite girder. In this pre-beam composite girder, the lower flange concrete is combined with the steel girder, so the self-rigidity increases by a large amount, and the girder height can be lower than that of a normal composite girder. In terms of,
This is extremely advantageous for construction of bridges that are subject to girder height restrictions. Furthermore, since the steel girder itself is not exposed, it has the advantages of not requiring maintenance such as painting, no noise, and fire resistance.

The pre-beam composite girder with these advantages has the configuration l! Because the base steel girder was formed with prestressed concrete added to the lower 7 lunges, there were problems with the processing structure when connecting the steel girders together.
In the past, it was commonly used for simply supported type bridges.

However, if the problems with the connection structure of prestressed steel girders are solved and it becomes possible to apply the pre-beam composite girder to the connected girder type, the advantages of the original pre-beam composite girder will be improved in terms of earthquake resistance, vehicle running properties, etc. It can be connected to a connected girder type bridge which is advantageous in terms of this, and the range of use of pre-beam composite girders can be further expanded.

The present invention was developed with the above-mentioned purpose in mind, and consists of connecting the girder ends of a number of prestressed steel girders with each other by a different structure, and then connecting them in front of a final single intermediate fulcrum. In this state, first concrete slabs are poured in the span leaving the area near the intermediate support, and the dominant dead load is borne by the simple girder system, and then the exposed parts of the left and right steel girders are secured with bolts, etc. By connecting and pouring concrete for the connecting section, and connecting the boundary surfaces of the lower 7 lunge concrete sections with adhesive, small after-dead loads such as ground coverings, handrails, pavements, etc. and live loads such as vehicles, etc. can be reduced. This paper attempts to provide a method for constructing a connecting girder using prestressed steel girders, which is characterized by being supported by a continuous girder system.

Next, the construction method according to the present invention will be described in detail with reference to an illustrated embodiment. FIG. 1), and b indicates the left end of the other steel girder (1) 2. The girder of the steel girder (l) is cut out in a KL-shape to include the upper 7 langes (3) at a portion approximately half the height of the web (λ), and the cut surface and the web are cut out to include the upper 7 langes (3). The tip surface of □ and K are respectively 0 or Horizontal end ml: (A kit stiffening plate (t) is provided between the middle part of the runner and the lower 7 lunge (j), and the horizontal position of this stiffening plate (6) is a few seconds apart. End plate (
4') A support pink) is protruding from the center of 2. On the other hand, the girder end of steel girder (1) 2 is attached to the lower 7 langes (pink) at about the height of half of the web (co) 2. j) Make a notch in an inverted shape so as to include 2, and connect this notch surface to the tip surface of the web (C) 2 and K.
are the inner vertical end plates (V) perpendicular to the middle nib (C) 2, respectively.
, the horizontal end plate (%) 8 and the top vertical end plates (-) are welded, and a stiffening plate is installed between the middle part of the horizontal face plate (m) and the upper 7 runci (j) 2. (4) 2 is provided.

These steel girders (1) and (1) are not shown, but the front bending curve of each of them is on the tensile side under a load. −)
(Jiz < 1) z b' is set to 1, and after this concrete hardens, the front deflection a is released and the weight is 7 below K.
Lange Concrete) (f), (r).

K prestress response is applied.

The erection of the prestressed steel girder described above is carried out in the order shown in Figure 1 a to eK. That is, as shown in Figure C aK, after the intermediate fulcrum shoe (10) is installed at a predetermined position, the press-less steel girder (1) is connected to one shoe (9) and in front of the intermediate fulcrum (
1O) and K. At this stage of erection, the prestressed steel girder (1), K is the web (K), is concreted with web concrete except for the ends, as shown in Figure 1.
, but this web concrete) (/
/), after the floor slab concrete as a later process, the second
As shown in Figures 1 and 3, one prestressed steel girder (1) 2 is connected between the notch end (support pin (7) of the ladle) and the other foot (2) of the steel girder (1). This steel girder (1) 2 is the horizontal end of the girder notch (p) shown in 1st wJb [(#) IL is the existing girder (1), K is the support bin ν
) It is constructed so that it is supported by K. Also, Jin's steel girder (
1) gK is the end g ($17) as in the steel girder (1) above.
Concrete) (//) 2 is pre-cast on the web 2 except for.

Next, as shown in FIG. At the same time, the upper 7 langes (3) and (J) of both steel girders (1) and (1) 2 are connected by temporary tightening, leaving the intermediate fulcrum part with the girder notch end (ge) (in). , K floor slab concrete) (/3), (
/J)2 was poured, and this concrete floor slab (13), (
13) Combine 2 with prestressed steel girders (1), (1) to form a pre-beam composite girder in the span. In addition, in this case, the connection by bolts (/J) K of both steel girders (1), (1), the deflection angle ft of both steel girders due to the support of the bearing pin (7)
- Take care not to restrict them.

At this point, the dead loads on both steel girders (1) and (7) RK are being supported by the simple girder system.

Next, in this state, as shown in Fig. 3, both steel girders (1),
(1), the girder notch end (4') ($17) of the &A
/) After final tightening K of (/J), vertical end plate (da) □
and (#) 3 and (#) 3 and (gong), and bolt (/#)
Connect from K, and then firmly connect the upper 7 langes (J) and G (3) 2 with the bolts (/6) inserted through the rising connecting plate (is), (/1) and z. Steel girder (1), (
/12 should be continuous.

After connecting both steel girders (/11 (1) 2), as shown in Fig. 1 d, concrete (ll) 3 is attached to the web of the intermediate fulcrum part of both steel girders (1) and (1), and to the upper 7 langes. Concrete floor slab (/J) will be placed. Although not shown in the drawings, at this stage concrete will also be placed on the transverse girders above the intermediate supports connecting each main girder.

After that, the adhesive (17) was injected into the interface between both the left and right girders (/1, (1), lower French concrete) (j), (j), and after the skeleton adhesive (17) had hardened. The girder is erected as a continuous girder, and thereafter supports the dead load of the ground cover, parapet, pavement, etc., or the live load of vehicles, etc., as shown in Figure 2e.

The construction method according to the present invention includes the above steps and has the following advantages. In other words, when constructing a general connecting girder, at the stage when the left and right girders are initially erected as a simple girder system, the connection ends of the left and right girders are supported separately by 21 temporary supports, and after the two girders are connected, two It is necessary to remove the temporary fulcrum and replace one intermediate fulcrum part KWl. On the other hand, in the construction method of the present invention, the connecting end of each steel girder has one L-shaped notch and the other an inverted-shaped notch, and first, the connecting end of each steel girder has one L-shaped notch (41). The steel girder (1), which is supported by one intermediate fulcrum part (10) ) on the L-shaped cutout end (ri) of the existing girder (1), which is supported by the support pin (7). The intermediate fulcrum part that supports the joint of the steel girder (I) is sufficient, and it can be installed from the beginning, so there is no need for complicated work such as relocating the shoe, and work efficiency is significantly improved. You can expect it.

Moreover, for the load before the connection of both steel girders (ll, Since there is no structure in place to restrain these deflection angles in any way during the temporary erection stage, the connecting girder system is designed so that the dominant dead load is borne by the simple girder system. It has the advantage that the function of the simple girder system during erection is faithfully maintained.

Also, the connection between both steel girders (ll, (1) and 2 is at the girder notch end ($1
(Shun) Because of the bolt connection at K, girder manufacturing errors and girder erection errors can be absorbed, making erection and connection work extremely easy.
pol for 2) (/2), vertical area increase (4
'), (#>3 and (4'), (Shun), K bolt (/41) connection, so the steel girder will bend and shear due to the dead load and live load that will be applied after the connection is erected. Capable of handling force.

Furthermore, bolt (1) connecting upper 7 langes 1j) and (3) 2
6), together with the rising connecting plate (/j) 1 (ts), performs the function of transmitting Franca and preventing slippage for the concrete floor slab (/J) 3.

However, in the Tonmoto construction method, multiple steel girders are connected to each other to form a connected girder, so the dominant dead load at the stage of erection is carried by the simple girder system, but after the connection, the ground is covered. The relatively small dead loads and live loads of balustrades, pavements, etc. can be supported by the continuous girder system, and the negative bending moment at the intermediate supporting point can be significantly reduced compared to ordinary continuous girders. ) The tensile stress of the slab caused by K, and the resulting stress of the concrete slab! Can reduce cracking ◇Also, while taking advantage of the advantages of pre-beam composite girders such as low noise, ease of maintenance, and fire resistance, as a continuous girder system, earthquake resistance and wheel running properties are improved, and moment balance is good. Therefore, it has advantages such as being more economical than a simple girder.

[Brief explanation of the drawing]

Figures 1 a and b are perspective views showing the structure of the girder end of a prestressed steel girder used in the erection method according to the present invention, Figures a to e are side views illustrating the erection process, and Figure 3 is a steel girder. 1 is a cross-sectional view taken along W-Pi@ in FIG. 2 a, FIG. 3 is a cross-sectional view taken along the v-v line in FIG. d is a sectional view taken along the line ■-■. In the figure, (/1, (/12...prestressed steel girder, (J), (
J), ... web, (J), (J), ... upper flange, extension) (ll171-girder notch end, ke), (j). ...Lower flange, +7) ...Supporting pin, Italy), (t
)2...Lower flange prestressed concrete, (
to> -... Before the intermediate fulcrum, (ll), (ll)2(l
l),...Web Concrete, (/J) (#)
<ta)...Volt, (/3)1 (/J)2 (/
J),...floor slab concrete, (+7)...adhesive. Patent applicant: Kawata Kogyo Co., Ltd.

Claims (1)

[Claims] a prestressed steel girder having a KL-shaped notch at the end of the L girder;
A prestressed steel girder having an inverted-shaped notch at the end of the girder is erected on an intermediate support with the hooks of the notch being different K,
Concrete slabs, etc., are poured into the spans of both steel girders, leaving the areas near the intermediate supports, and the spans are made into composite girders made of prestressed steel girders.Then, the notches on the left and right steel girders above the intermediate supports are constructed. After connecting the steel girders with bolts, etc., and placing the remaining concrete at the intermediate fulcrum, adhesive is injected into the concrete interface between the lower flange of both the left and right girders at the intermediate fulcrum. A method for constructing connected girders using prestressed steel girders, which is characterized by the ability to receive loads such as dead loads and live loads as continuous girders.