KR200296427Y1 - Assembly structure of lattice girder having high strength spider - Google Patents

Abstract

This design reduces the weight of lattice girders, increases tensile strength, increases the unity with shockcrete, reduces the amount of shockcrete rebound by applying high-strength reinforcing bars. It consists of a plurality of steel bars extending in parallel and spaced apart from each other, and a plurality of spiders having a triangular truss shape such as a three-dimensional closed polygon by bending both ends of the steel rod and welding the ends thereof. (100) is banded from SD500W to reduce the weight of the grid support and increase the tensile strength, and the radius (R) of each of the banding portions (102 to 107) is 2 of the material diameter (D) to prevent breakage and load distribution. It is banded more than twice (R≥2D).

Description

ASSEMBLY STRUCTURE OF LATTICE GIRDER HAVING HIGH STRENGTH SPIDER}

The present invention relates to a lattice beam assembly structure having a high-strength spider, in particular, the assembly structure and high-strength force, which can easily fasten the lattice girders (lattice girder) used in the tunnel construction through NATM (New Austria Tunnel Method) method, It relates to a high strength spider.

In general, in the civil engineering of tunnels, it is important to construct the construction before the initial ground deformation is suppressed after excavation. Therefore, a method that satisfies both air shortening and structural stability has been performed.

For example, the NATM method prevents the ground from deteriorating by maintaining the ground in triaxial compression by installing shotcrete and rock bolts with good adhesion and flexibility before the initial ground deformation after excavation. It is possible to make the best use of the supporting force of the ground itself by forming the ground arch, measure the stress and displacement behavior of the surrounding ground and the ground hole during construction, and control the construction to ensure the stability of the tunnel. Tunnel civil engineering.

In the NATM method, the ground itself acts as the main support for the tunnel, and lock bolts, shock concrete, wire mesh and steel ribs are used to prevent ground deformation, utilize ground strength, and improve tunnel safety. Used.

The members used for steel beams include H-beams, steel pipes, U-beams, and trussgirders, and lattice beams are used to minimize air gaps and minimize back voids during shock casting. The use of lattice girder is common.

Lattice beams are welded at regular intervals between spiders or connecting elements that are bent in a longitudinal triangular truss shape, that is, a three-dimensional closed polygon, between three to four high-strength upper and lower heterowires. It is a gangjibo for tunnels that initially supports the tunnel excavation section during tunnel construction

Referring to the grid support according to the prior art in more detail, as shown in Figure 1, the three steel bars (1, 2, 3) extending in parallel and spaced apart from each other, and both ends after bending the steel rod The welding consists of a spider 4 which is a plurality of connecting elements having a triangular truss shape such as a three-dimensional closed polygon.

Among the steel bars, the central first bar 2 has a cross-sectional area that is twice the cross-sectional area of the two second and third bars 1 and 3, and is welded to the upper part of the spider 4. The lower portion of the spider 4 is welded to the upper portions of the second and third bars 1 and 3, respectively, so that the spider 4 is able to connect the first to third bars 1, 2 and 3, respectively. It will have a structure that interconnects.

In the conventional grid girders, the spider 4 has a generally yielding surface with a minimum yield stress of 520 N / MM², the bending radius of the polygon is less than twice the diameter of the rod, and the rod undergoes bending processing. Previously, it was cold-formed by rolling or stretching or drawing processing, but the lattice gi itself has a heavy weight, so it is necessary to reduce the weight and structural stability is required according to the weight reduction.

In addition, since the spider used in the conventional grid support requires more than the steel bar, even for automatic mass production of the spider, the bending radius (R) value and the material diameter (D) that match the manufacturability of the bending machine There is a demand for an optimal design ratio according to the ratio.

Therefore, in the conventional grid girders only limited to the shape of the spider, since the weight of the girders and the tensile strength and the unity of the shockcrete were not considered, the lattice girders could not exhibit satisfactory structural performance in the practical application of the NATM method. Resulted.

In addition, when connecting the conventional grid girders to each other, a flange structure having a general bolt and nut and a simple bolt hole is required, so that each tightening tool is required for the bolt and nut, or it is difficult for the worker to tighten the bolt during high work. Work environment was provided.

Therefore, the object of the present invention was devised to solve the problems of the prior art as described above, by applying a high-strength reinforcement to reduce the weight of the grid support, increase the tensile strength, increase the sense of unity with shockcrete, shock rebound The present invention provides a lattice support assembly structure having a high-strength spider that can reduce the amount and prevent the fracture of the spider's bending part according to the optimum design.

1 is a perspective view for explaining the configuration of a general grid support;

2 is a perspective view for explaining the shape of a high-strength spider according to an embodiment of the present invention,

3 is a perspective view for explaining the assembly structure between the grid girders having a high-strength spider shown in FIG.

4 is a front view for explaining the flange of the grid gird shown in FIG.

5 is a front view and a right side view for explaining the shape of the bolt shown in FIG.

♠ Explanation of symbols on the main parts of the drawing ♠

1, 2, 3: steel bar 100: spider

200, 201: flange connection means 202, 205: base plate

203, 204: flange plate 210, 221: long hole

220, 211: hole 230: bolt

232: oval protrusion 240: nut

The object of the present invention is a high-strength spider consisting of a plurality of steel bars extending in parallel and spaced apart from each other, and a plurality of spiders having a triangular truss shape such as a three-dimensional closed polygon by welding both ends after bending the steel rod. In the grid support assembly structure having a structure, the spider 100 is band-molded with SD500W material for lightening the grid support and increasing the tensile strength, and the radius of each bending band is 2 of the material diameter to prevent breakage and load distribution. It is achieved by a grating support assembly structure having a high-strength spider characterized in that the bending more than twice.

In addition, according to the present invention, the grating support further comprises a flange connecting means consisting of a flange plate having a 'b' angle shape bent vertically from the base plate fixed by welding, the length of the base plate of the flange plate It is preferably formed relatively longer than the length.

In addition, according to the present invention, it is preferable that the flange plate is formed with elliptical long holes and circular holes staggered from each other at a corresponding position, thereby preventing the twisting when the bolt and the nut are fastened to enable precise construction.

In addition, according to the present invention, the bolt has a bolt head, an elliptical protrusion, and a screw shaft are integrally formed, and when the bolt is fastened, the elliptical protrusion is hermetically matched to the long hole to restrict the rotation, thereby facilitating bolt tightening operation. It is desirable to.

Referring to the preferred embodiment according to the present invention in more detail by the accompanying drawings as follows.

In the drawings, Figure 2 is a perspective view for explaining the shape of the high-strength spider according to an embodiment of the present invention, Figure 3 is a perspective view for explaining the assembly structure between the grid girders having a high tension spider shown in FIG. FIG. 4 is a front view for explaining the flange of the grid support shown in FIG. 3, and FIG. 5 is a front view and a right side view for explaining the shape of the bolt shown in FIG.

As shown in Figure 2, the grating support assembly structure having a high-strength spider of the present invention is three steel bars (1, 2, 3) extending in parallel and spaced apart from each other when described in connection with the prior art It consists of a three-dimensional closed polygonal spider 100 welded between these bars (1, 2, 3).

Here, the spider 100 is manufactured by a continuous production apparatus of a spider using a variable mold, which is a kind of banding machine, and welds a portion 101 where both ends meet.

In particular, the steel bars (1, 2, 3) uses a general structural reinforcing bar, as in the prior art, but the material of the spider 100 is a conventional high strength to provide an increased effect, such as light weight and tensile strength The new high-strength reinforcing bars of the SD500 and SD500W series are used, which are 25% stronger than the reinforcing bars of the SD400 series.

SD500W is a rebar product manufactured by I & I STEEL Co., Ltd. (representative: Yu In Kyun, Jeong Suk Soo) .The yield stress measured by material test in the y-axis direction of rebar is 500N / mm2 or more. It has high strength and high tensile properties. Therefore, since the grating support of the present invention is made of high-strength reinforcement (SD500W), the sense of unity with the shockcrete can be increased, and the amount of shockcrete rebound can be reduced.

In addition, the spider 100 of the present invention is manufactured by the above-mentioned continuous production apparatus, the radius (R) of each bending portion 102-107 is more than twice the material diameter (D) (R≥2D) It is characterized in that it has a structure capable of preventing the breaking of the banding portions 102 to 107 due to external loads in advance and distributing the load elastically and safely.

As shown in Figures 3 and 4, the two grating supports 10, 20 having a plurality of high-strength spider 100 of the present invention described above, the bolt holes (easily bolted when designed in the length-to-assembly) Fastening with flange connection means 200, 201 having 210, 211, 220, 221.

Flange connecting means (200, 201) of the present invention is a flange having a 'b' angle shape by vertically bent from the base plate (202, 205) fixed by welding to the right and left of the steel bars (1, 2, 3), respectively It consists of plates 203 and 204.

The length (A) of the base plates (202, 205) is formed relatively longer than the length (B) of the flange plates (203, 204), and thus the welding length and the contact area with the steel bars (1, 2, 3). Since it can be taken widely, it is possible to structurally reinforce the joint part, which is the weak part of the grid support for tunnel.

In particular, the bolt holes 210, 211, 220, and 221 formed in the flange plates 203 and 204 are formed with different diameters at positions corresponding to each other.

That is, the first flange plate 203 has an elliptical first long hole 210 and a circular first hole 211 formed at the top and bottom thereof, and the second flange plate 204 corresponding to the top and bottom thereof. A circular second hole 220 and an elliptical second long hole 221 are drilled. In this case, the first long hole 210 and the second long hole 221 are alternately disposed on the first and second flange plates 203 and 204.

When the grid supports 10, 20 having such flange connecting means 200, 201 are connected to each other, each of the first flange plate 203 and the second flange plate 204 is interviewed with each other, and at the same time, The first long hole 210 and the second hole 220 coincide with each other, and the second long hole 221 and the first hole 211 coincide with each other.

At this time, the bolt 230 is inserted into each of the long holes through holes 210, 211, 220, 221 has a shape specially designed in the present invention.

That is, as shown in Figure 5, the bolt 230 is a hemi-spherical, plate-shaped, hexagonal and other common bolt head 231, an elliptical protrusion 232 formed integrally on the lower surface thereof, and integrally on the lower axis of the shaft It is formed by a screw shaft 233 protruding and having a thread.

In particular, the shape of the elliptical protrusion 232 is formed in a shape that can be hermetically matched to the long holes (210, 221), when the bolt 230 is fully inserted into the long holes (210, 221), the elliptical protrusion ( Since the 232 is fastened to the long holes 210 and 221 and cannot be rotated, the tightening tool for tightening the bolt head 231 is not necessary, and only the tightening tool for the nut 240 is provided. It can be easily assembled.

This feature provides a very easy and convenient assembly work environment in the high-assembly of the lattice beam, and at the same time, the user can simply fasten the bolt 230 and the nut 240 with one hand using only one tightening tool. will be.

In addition, since the elliptical long holes 210 and 221 are alternately arranged at the flange plates 203 and 204, the elliptical long holes 210 and 221 have an effect of preventing twisting of the fastening portion and precision construction after assembling the bolts.

As described in detail above, the grating support assembly structure having the high-strength spider of the present invention can realize the weight reduction of the grating support and the excellent tensile strength by bending the spider from the high-strength steel (SD500W) material. There is an effect that can provide.

In addition, in the assembly structure of the present invention, the length of the base plate of the flange means is formed relatively longer than the length of the flange plate, so that the welding length and the contact area can be widened, so that the joint part, which is a weak part of the grid support for the tunnel, There is an advantage that can be reinforced.

In addition, in the case of the spider provided in the assembly structure of the present invention, since the radius of each bending portion is bent more than twice the diameter of the material, it is possible to prevent the bending of the bending portion due to external load in advance, and to make the load elasticity. It has the effect of being distributed safely.

Further, in the assembly structure of the present invention, by arranging the bolt having an elliptical protrusion, the corresponding long hole and the general circular hole on the flange plate, the bolt can be fastened with one hand, so that the high work is easy and the twisting of the fastening part is easy. There is an advantage that can be prevented precision assembly.

The grid support assembly structure having a high-strength spider of the present invention has been described above with the accompanying drawings, but this is merely illustrative of one embodiment of the present invention and is not intended to limit the present invention.

Claims (4)

A lattice beam assembly structure having a high tension spider consisting of a plurality of steel bars extending in parallel and spaced apart from each other, and a plurality of spiders having a triangular truss shape like a three-dimensional closed polygon by bending steel rods and welding both ends thereof. In The spider 100 is band-molded with a SD500W material to reduce the weight of the grid girders and increase the tensile strength, and the radius R of each of the banding portions 102 to 107 is used to prevent breakage and load distribution. A lattice support assembly structure having a high-strength spider, characterized in that the bending is more than twice (R≥2D). The method of claim 1, The grating support further includes flange connecting means (200, 201) consisting of flange plates (203, 204) having a 'b' angle shape vertically bent from the base plate (202, 205) fixed by welding, the base A grid support assembly having a high tension spider, characterized in that the length (A) of the plate (202, 205) is formed relatively longer than the length (B) of the flange plate (203, 204). The method of claim 2, Elliptical long holes 210 and 221 and circular holes 220 and 211 are formed in the flange plates 203 and 204 so as to alternate with each other at a corresponding position, so that the bolt 230 and the nut 240 are fastened. Lattice support assembly structure having a high-strength spider, characterized in that the precise construction is possible by preventing the twist. The method of claim 3, wherein The bolt 230 has a bolt head 231, an elliptical protrusion 232 and a screw shaft 233 integrally formed, the elliptical protrusion 232 is airtight in the long holes (210, 221) when the bolt is fastened The lattice support assembly structure having a high-strength spider, characterized in that the rotation is constrained to facilitate the bolt tightening operation.