JPH0718130B2 - Compound pier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a composite pier in which a pedestal portion is made of reinforced concrete or steel reinforced concrete and a lateral beam is made of steel, and particularly relates to a stanchion-lateral beam connection structure thereof. It is used for piers such as road bridges.

[Conventional technology]

As conventional piers for road bridges, as shown in Fig. 13, the entire pier 1 is made of reinforced concrete or steel reinforced concrete, including footing, and the pier 1 is made of steel as shown in Fig. 14. There is something I did.

When the horizontal beam 3 in FIG. 13 is also made of reinforced concrete, first the reinforcement 16 of the pedestal 2 is laid out, the concrete 18 of the pedestal is placed, and then the support work, scaffolding, etc. are installed around the pedestal 2. Then
Reinforcing the reinforcing bar 10 of the horizontal beam 3 and placing concrete 18,
Build pier 1.

As shown in Fig. 14, when the entire pier 1 is made of steel, the anchor frame consisting of the anchor beam 9 and the anchor bolt 8 is embedded in the concrete footing 6, and the steel pier 1 made by factory is used as the anchor bolt. 8
Then, the steel bridge pier 1 is fixed.

The above structure is not limited to the T-shaped piers shown in Figs. 13 and 14, but is common to the ramen-shaped piers and the inverted L-shaped piers.

[Problems to be Solved by the Invention]

However, when all the columns and cross beams are made of reinforced concrete, the formwork and supporting work to support it are indispensable, and the construction is complicated and takes a long time. In addition, due to the construction of supports and scaffolding in cities, etc., it occupies a considerable space during the construction period. Therefore, if the road under the bridge is in service, a traffic stop is required.

In addition, when the width of the superstructure is large, the overhanging length of the lateral beam will inevitably become large, but if this is constructed with reinforced concrete, it will have an extremely large cross section, the weight of the pier frame will increase, and the foundation structure such as piles 7 will also increase. The size is large and the construction cost increases.

On the other hand, the steel bridge pier 1 made entirely of steel can be manufactured in a batch or divided manner, and has good workability on site,
Minimal installation of scaffolding and scaffolding. Also, there is almost no need to stop the traffic and the construction period is shortened. But,
It is much more expensive than reinforced concrete piers,
In addition, the amount of steel material such as the anchor frame for connecting the pedestal 2 and the concrete footing 6 increases, and the construction for that becomes complicated.

INDUSTRIAL APPLICABILITY The present invention is a composite bridge pier that can reduce the construction space of the cross beam to minimize the traffic stop and the construction cost when the construction period is short and bridges are used together with roads in the bridge pier construction in cities. The purpose is to provide a rational pedestal-lateral beam joint structure in.

[Means for Solving the Problems]

In the present invention, the pier is made of reinforced concrete or steel reinforced concrete, and the cross beam is made of steel to form a composite pier having a T-shape, a ramen shape, an inverted L-shape, etc.

The main pillar of the composite pier of the present invention is not bent and fixed at the top of the pillar, and is projected from the top as it is to be used as a joint material with a steel cross beam, so that it is not necessary to provide a new joint steel material. Is rational and economical.

The connecting structure is, as a first method, a method in which a stanchion main bar having a threaded portion is inserted into a steel horizontal beam and fastened with a nut, and as a second method, nut fastening is not performed, and concrete or mortar is put in a joint portion of the horizontal beam. And the like, or a method of using the first and second methods in combination.

Further, in these methods, when the hardened material is filled in the joint portion, the amount of the hardened material can be reduced by adopting a structure in which the hardened material is filled only around the stanchion main bars.

[Action]

In general, it is economically advantageous to use a reinforced concrete member such as a pillar member in which the compressive force is dominant. However, in the case of a lateral beam with a large overhanging length, that is, a member such as a T-shaped, ramen-shaped, or inverted L-shaped lateral beam of a bridge pier, the bending moment becomes extremely large due to its own weight and seismic load, rather than using reinforced concrete. It is more rational and economical to use steel from the viewpoints of weight reduction and workability.

In consideration of the above-mentioned mechanical characteristics, the composite pier according to the present invention has a large overhang and a large bending moment acts on the pier consisting of the stanchion and the lateral beam projecting to the left and right at the upper end of the stanchion. The horizontal beam is made of steel, and the pedestal where compression force is dominant is made of reinforced concrete or steel-framed reinforced concrete, making it the most rational and economical structure.

〔Example〕

 Next, the illustrated embodiment will be described.

1 and 2 show that the pillar 2 of the pier 1 is made of reinforced concrete, and the main bar 16 of the pillar 2 is projected from the top end of the pillar 2 as a threaded joint reinforcing bar or an end threaded reinforcing bar, while the horizontal beam is used.
Reference numeral 11 is an example in which a stanchion main bar 16 is inserted into a steel cross beam 11 made of steel, and is fastened and fixed to the upper end surface of the steel cross beam 11 (on the upper flange 12 in FIG. 2) with a nut 17.

Thereby, the pedestal 2 and the steel cross beam 11 are integrated, and the compressive force is applied between the lower flange 13 of the steel cross beam 11 and the top end concrete of the pedestal 12 against the constant load and the earthquake load. Further, the tensile force is transmitted between the upper flange 12 of the steel cross beam 11 and the main bar 16 protruding from the pedestal 2.

In this joint structure, in order to satisfy the design conditions (such as the problem of stress transmission between the pedestal 2 and the steel cross beam 3 due to shrinkage of concrete, etc.), the lower flange 13 of the steel cross beam 11 and the pedestal 2 top It is desirable that the joint surface 23 with the edge concrete is filled with a filler such as non-shrink mortar or resin by injection or the like to enhance the adhesion of the joint surface. Further, in order to improve the adhesion of the joint surface, it is effective to introduce an axial force into the stanchion main bar 16 with a hydraulic jack or the like.

Further, in FIG. 2, 15 is a steel cross beam 11 and a column main bar 16 is a nut.
In order to fasten with 17, the stiffener ribs are provided on the steel cross beam 11, and the column main reinforcement 16 is inserted at an appropriate position between the stiffening ribs 15.

As a normal joining structure, the above structure is simple,
When the amount of the stanchion main reinforcement 16 fastened to the steel cross beam 11 is set to the necessary minimum amount, if an excessive load exceeding the design acts, the elasticity and plastic elongation of the stanchion main reinforcement 16 in the joint are large,
It has been proved by experiments based on the present invention and FEM analysis (finite element method) that the rotational deformation of the joint becomes large and the toughness of the joint may be impaired.

On the other hand, FIG. 3 shows an example in which the fastening position of the stanchion main bar 16 is inside the joint, the free length of the reinforcing bar is shortened to suppress the elongation, and the toughness of the joint is improved.

FIG. 9 and FIG. 10 show a more specific embodiment corresponding to the embodiment of FIG. 3, one between the stiffening ribs 15 provided at a predetermined interval in the joint diaphragm 14. To favorite,
Two main struts 16 are inserted inside and two outside, and are fastened with nuts 17 inside the joint.

FIGS. 4 and 5 further show the main pillar 16 of the stanchion formed by the stiffening rib 15 and the diaphragm 14 which further support the nut fastening portion.
This is an example in which the surrounding space is filled with a hardening material such as mortar 20. In this case, since the force is transmitted by the adhesion between the mortar 20 and the reinforcing bar 16, the extension of the stanchion main bar 16 is significantly suppressed, and the stiffening action of the filling mortar 20 causes the steel cross beam 11 and the stanchion 2 to be separated from each other. It is possible to obtain an excellent effect that the load transmission of becomes smooth.

On the other hand, FIG. 6 shows that a concrete casting hole 22 is provided in the upper flange 12 of the steel cross beam 11, the steel cross beam 11 is installed on the pedestal 2, and then concrete 19 is filled, so that the legs are attached only by the adhesive force. Pillar
This is an example in which 16 is fixed. In this case, since the filling concrete 19 can disperse the stress in the joint portion, the reliability of the joint structure is significantly improved. In addition, in order to secure the safety during the construction of the horizontal beam 11 and during the hardening period of the filled concrete 19, part of the stanchion main reinforcement 16 is to be attached to the upper flange of the steel horizontal beam 11.
The nut may be fastened to 12 or the lower flange 13.

Fig. 7 shows an application example in which the joint is filled with concrete and fixed by adhesion. Concrete is placed in the space formed by stiffening ribs 15 and diaphragms 14 around the main pillar reinforcement 16. We are trying to reduce the weight of the horizontal beam by filling it with or mortar 20.

Further, FIG. 8 shows an application example in which the stanchion main bar 16 is fixed by using nut fastening together with adhesive force.

The above joint structure is not limited to the T-shaped composite pier, but can be used for any of the composite piers (see Fig. 11 and Fig. 12) such as ramen-shaped and inverted L-shaped piers. It can be used in combination according to.

Further, in the above embodiment, the main girder 4 of the superstructure is the steel cross beam 11.
In the case of being erected on the upper part of the upper flange 12 of the present invention, in the joint structure of the present invention, for example, as shown in FIG. It is also applicable when installed on the member 11a.

Although the main girder 4 has a box-shaped cross section in FIG. 15, the same applies to an I-shaped cross section.

[Advantages of the Invention] By constructing the cross beam from steel, the construction period is shortened, and the form and support of the cross beam are not required. Therefore, even when constructing on a road in service, it is not necessary to take measures such as stopping traffic.

By using a steel cross beam, it is easier to construct a girder or other superstructure recess than a reinforced concrete cross beam, and the construction accuracy is also improved.

Compared with the case where all are made of reinforced concrete, the weight of the entire pier structure is significantly reduced and the top heavy structure is avoided, which is advantageous in seismic design and the basic structure is smaller. Therefore, it is suitable when the construction space is limited and the construction space is limited, such as in a city.

By projecting the main bar of the pedestal portion and using the nut, the cross beam can be easily and quickly fixed to the pedestal.

By filling the joint between the pedestal portion and the cross beam with concrete, both can be reliably anchored, and it can be used in combination with anchoring with a nut.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of application of the present invention to a T-shaped composite pier, FIG. 2 is a vertical sectional view showing an essential part in the embodiment of FIG. 1, and FIGS. A vertical cross-sectional view showing a structure of a joint between a pillar and a steel cross beam in another embodiment,
9 and 10 are a vertical sectional view and a horizontal sectional view showing an example of a more specific structure in the embodiment of FIG.
Fig. 11 is a vertical sectional view showing an example of application to a rigid-frame composite pier, Fig. 12 is a vertical sectional view showing an example of application to an inverted L-shaped composite pier, and Figs. 13 and 14 show conventional examples. FIG. 15 is a perspective view showing a modification in which the steel cross beam and the main girder are at the same level in the present invention. 1 ... Bridge pier, 2 ... Pillar, 3 ... Horizontal beam, 4 ... Main girder, 5
…… Road, 6 …… Footing, 7 …… Pile, 8 …… Anchor bolt, 9 …… Anchor beam, 10 …… Reinforcing bar, 11 ……
Steel horizontal beam, 12 …… upper flange, 13 …… lower flange, 14…
… Diaphragm, 15 …… Stiffening rib, 16 …… Pillar main bar, 17
…… Nut, 18 …… Concrete, 19 …… Filled concrete, 20 …… Filled mortar, 21 …… Reinforcing rod insertion hole, 22 ……
Concrete pouring hole, 23 ... Joint surface

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Osamu Iimura 1-3-3 Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries, Ltd. (72) Inventor Seiyo Morimoto 1-1-1 Otemachi, Chiyoda-ku, Tokyo No. 3 Sumitomo Metal Industries, Ltd. (72) Inventor Yozo Yui 1-3-1, Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries, Ltd. (72) Inventor Yoichi Kobayashi 1 Otemachi, Chiyoda-ku, Tokyo 1st-3rd Sumitomo Metal Industries, Ltd. (56) References Japanese Patent Laid-Open No. 50-54131 (JP, A)

Claims (4)

[Claims] 1. A pier of a pier is made of reinforced concrete or steel reinforced concrete, and a cross beam is made of steel, and a main bar of the pier is projected from an upper end of the pier to be connected to the cross beam. Composite pier. 2. A hardening material is inserted into a steel horizontal beam through which the main bar protruding from the upper end of the pedestal is inserted, and a hardening material is provided inside the joint between the stanchion and the horizontal beam or in a space surrounding the main bar at a predetermined position in the joint. The composite pier according to claim 1, wherein the composite pier is filled with and connected. 3. The main bar projecting from the upper end of the pedestal is inserted into a steel horizontal beam, and a nut is screwed into a threaded portion provided at least on the upper part of the main bar to form an upper end surface of the steel horizontal beam or steel. The composite pier according to claim 1, wherein the pier is fastened to the inside of the horizontal beam. 4. The composite pier according to claim 3, wherein a hardening material is filled in the entire joint portion of the stanchion and the cross beam or in a space surrounding the main bar at a predetermined position in the joint portion.