JPH0651973B2 - Yamadome structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mountain retaining structure applied when constructing an underground structure.

(Prior Art) One of the mountain retaining methods when constructing an underground structure is a steel beam construction method. Among them, the method of constructing a horizontal girder is called the horizontal beam method, and the method of constructing a slant is called a diagonal beam method.

In any of the construction methods, it is composed of an uprising, a cutting beam, and a striking beam, and the uprising works to suppress the earth pressure transmitted through the mountain retaining wall and to transmit it to the cutting beam.

Therefore, since the uprising plays the role of the beam supported by the cutting beam,
It will be subjected to bending and shear stresses.

Usually, H-shaped steel is used as the upholstery material, but when the spacing between the crossbeams increases, the acting stress increases and it becomes impossible to support it with one member.

In such cases, i) reduce the spacing of the cross beams, or
ii) Install a striking beam (c) between the aneurysm (a) and the girder (b) as shown in Fig. 3, or iii) Raise the aneurysm (a) as shown in Fig. 4. The joint parts (j) of each layer are arranged so as to be superposed on the inside and outside so that they are located in a different position.

(Problems to be Solved by the Invention) However, according to the method of the above i), the number of beam members increases,
The spacing between the crossbeams is narrow and workability is poor. Further, according to the method of ii), since the fired beam is arranged, the steel material to be used is increased, the cost is increased, the construction is troublesome, and the fired beam interferes with excavation work and the workability is deteriorated. Further, according to the above method iii), since the abdomen is arranged in the inner and outer double layers, the steel material to be used is increased and the cost is increased.

The present invention has been proposed in view of the above problems of the prior art, and an object thereof is to provide a mountain retaining structure that is structurally rational, has good workability, and is economical.

(Means for Solving the Problems) In order to achieve the above object, the Yamadome structure according to the present invention is
Providing a bulging joint at the position where the cut beam is arranged, joining adjacent bulges at the joint with a high-tensile bolt, and connecting both bulges adjacent to each other across the joint. A short H-shaped steel piece is spliced and joined across each inner side surface, and a beam end portion is joined to the piece.

(Operation) According to the present invention, as described above, the abutment portion is provided at the position where the truss is arranged, and the short portion is provided across the inner surfaces of the adjacent abutments with the joint portion interposed therebetween. By splicing and joining H-shaped steel pieces, the shear strength at the joint portion of the uprising is increased,
Further, by adjoining adjacent abutments at the joining portion with a high tension bolt, it is possible to prevent a decrease in bending rigidity of the abutments and to act as a continuous beam with the cutting beam position as a fulcrum. .

(Examples) The present invention will be described below with reference to illustrated examples.

(1) is an upholstery made of H-shaped steel, which is provided with the joint of (1) at the position where the beam (2) is arranged, and the adjacent upholstery (1) is provided at the joint. ) End plates (3) are fastened together with high tension bolts (4).

Further, the outer flange of the short H-shaped steel piece (5) is spliced across the inner surfaces of the adjacent abutments (1) with the joint portion sandwiched therebetween, and the inner flange is joined with the outer flange. The beam (2) is joined to the above with bolts (7).

In the figure, (8) and (9) are end plates of the H-shaped steel piece (5) and a stiffening member, (10) is a mountain retaining wall, and (11) is a packing.

Usually, since the uprising is formed by joining several meters of H-shaped steel material, the bending rigidity and the shear strength are lowered at the joined portion. Therefore, without the use of the striking beam, the agitated joint is located near the center of the span and the deformation is significantly increased. On the contrary, when the joint is located near the cut beam, the shear strength becomes a problem.

According to the above-mentioned embodiment, the joint portion of the uprising (1) is arranged at the attachment position of the beam (2), and the short H-shaped steel piece is straddled over each inner surface of the adjacent uprising (1). Since (5) is joined via the bolts (6), the shear strength at the joint end of the agitator (1) is increased on the contrary.

Furthermore, since the end plates (3) of the adjacent agitating members (1) at the joints are tightened with the high tension bolts (4), a decrease in bending rigidity is prevented, and the agitating members (1) are cut beams. It acts as a continuous beam with the position as a fulcrum, and as a result, the bending moment distribution of the uprising (1) is as shown in Fig. 2, and it is possible to support a considerably large span without a striking beam.

(Effect of the invention) As described above, according to the present invention, the joint portion of the abdomen is located at the position where the cutting beam is arranged, and the inner surface of the abdomen adjacent to each other is sandwiched across the joint portion. Splicing a short H-shaped steel piece,
By joining, the shear strength at the joint portion of the abdomen is increased, and the adjacent abutment portions at the joint portion are joined with a high tension bolt to prevent the bending rigidity of the abdomen from lowering. , It works as a continuous beam with the cutting beam position as a fulcrum, and it is possible to support a considerably large span without using a striking beam.

As described above, according to the present invention, it is not necessary to arrange the cutting beams densely to reduce the span, to provide the firing beams, or to arrange the waving double as in the conventional case, and the steel material used is saved. The work is improved, the structure is rational, and the economical structure of the Yamadome structure is constructed.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a mountain retaining structure according to the present invention, FIG. 2 is a bending moment distribution diagram of a rising, and FIGS. 3 and 4 are examples of conventional mountain retaining structures. FIG. (1) …… raised, (2) …… cut beam (4) …… high tension bolt (5) …… short H-shaped steel piece

Claims (1)

[Claims] 1. An abdominal joint is provided at the position where the beams are provided,
Adjacent abutments at the same joint are joined by high tension bolts, and a short H-shaped steel piece is spliced across the inner surfaces of the adjacent abutments with the joint sandwiched therebetween. The Yamadome structure is characterized in that the end of the beam is joined to the same piece.