JP3695544B2 - Shear bolts for repair and reinforcement of slopes and inner surfaces of tunnels - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a shear bolt for repairing / reinforcing a slope or an inner peripheral surface of a tunnel.
[0002]
[Prior art]
As for the repair and reinforcement of the slope covered by the concrete spraying method, new concrete is sprayed as a new spraying member 2 on the surface of the old concrete 1 as shown in Fig. 10. In order to achieve integration with the blowing member 2, it is common to stretch a wire mesh lath 20 or the like on the surface of the old concrete 1. In the figure, reference numeral 3 denotes a set pin of the wire mesh lath 20.
[0003]
However, the attachment of the wire mesh lath 20 leads to an increase in the rate of rebound after the new spraying member 2 is sprayed. Also, in order to hold the new spraying member 2 with poor adhesion by the iron mesh, conversely, the old concrete 1 This hinders the spraying work to adhere to the surface. Moreover, the lath tensioning work for stretching the wire mesh lath 20 is extremely troublesome.
[0004]
FIG. 11 shows a case of a tunnel. Similarly, a new concrete is sprayed as a new spraying member 2 on the surface of the old concrete 1 for repair and reinforcement of the inner peripheral surface. This work is extremely troublesome.
[0005]
Therefore, one of the applicants proposed a method for integrating the old concrete and the new spray member using an anchor bolt as shown in Japanese Patent Application No. 6-19442 filed earlier. The bolt used in such a method is provided with a lock part at the lower part of the screw part to which the nut is attached, and further, a nut provided with a projecting piece radially is screwed into the upper end of the screw part of the anchor bolt. The upper half and the lower half are separated from each other with a cut portion cut at an acute angle as a boundary.
[0006]
And when this anchor bolt is buried in the existing spray layer or directly in the natural ground and planted on the slope of the natural ground, when the nut is turned and moved in the direction of the lock portion, pressure is applied to the lock portion. The upper half and the lower half are inconsistent, and the discrepancy is locked.
[0007]
Screw the nuts with the protruding pieces radially into the tip of the threaded part protruding from the slope of the anchor bolt thus planted, and place the new spraying member on the surface of the old concrete so that this nut is completely embedded To apply.
[0008]
To reuse such an anchor bolt, loosen the nut and pull it out.
[0009]
[Problems to be solved by the invention]
Thus, since the conventional anchor bolt assumes reuse, if a nut is loosened, a lock part and a screw part can be extracted from a natural ground. On the contrary, if the nut is loosened for some reason after being buried, the lock is loosened, and the reliability is lowered.
[0010]
The object of the present invention is to solve the disadvantages of the above-mentioned conventional example, the lock can not be released even if the nut is loosened after burying, and the method that can integrate the old concrete and the new spraying member with high reliability. The purpose is to provide shear bolts for repairing and reinforcing surfaces and inner peripheral surfaces of tunnels.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a cylindrical lock portion having an inner diameter slightly larger than the outer peripheral surface diameter of the rod-shaped portion at the lower part of the screw portion on the outer periphery of the rod-shaped portion at the lower portion of the screw portion, An anchor bolt having a stopper at the lower end and a nut provided with a projecting piece in a radial manner is screwed into the upper end of the threaded portion, and the lock portion is cut at an acute angle. Consists of upper and lower halves, and stepped irregularities like ratchet teeth that prevent the upper half from returning in the direction opposite to the tightening direction are formed on the cut surfaces of the upper and lower halves. This is the gist.
[0012]
[Action]
According to the present invention, when pressure is applied to the lock portion by tightening the nut, the upper half portion and the lower half portion are misaligned, and the misalignment is locked. At this time, the upper half and the lower half are engaged with the unevenness formed on the cut surface, and the upper half does not return in the direction opposite to the tightening direction, and the lock is not released even if the nut is loosened.
[0013]
And return of an upper half part can be prevented certainly, and processing becomes easy.
[0014]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a working state showing a general example of a repair / reinforcement shear bolt such as a slope or an inner peripheral surface of a tunnel, and FIG. 2 is a perspective view of the same. 5, a nut 6 is attached to the upper portion of the lock portion 5 to form an anchor bolt 7, and nuts 9 having radial protrusions 8 are screwed onto the upper ends of the screw portions 4 of the anchor bolt 7.
[0015]
The lock portion 5 is divided into an upper half portion 11 and a lower half portion 12 with a cut portion 10 cut at an acute angle as a boundary. That is, the upper half portion 11 and the lower half portion 12 are in contact with the respective cut surfaces 13 and 14, and the inner diameter of the lock portion 5 is slightly larger than the outer peripheral surface diameter of the rod-like portion below the screw portion 4.
[0016]
Further, a stopper 17 for receiving the lock portion 5 is provided at the lower end of the rod-like portion below the screw portion 4. The stopper 17 has a diameter equal to or larger than that of the lock portion 5 and prevents the lock portion 5 from falling off.
[0017]
In the bolt with such a configuration, the cut surfaces 13 and 14 are formed with unevenness 15 for preventing the upper half 11 from returning in the direction opposite to the tightening direction when the nut 9 is tightened. The shape of the cut surfaces 13 and 14 is generally a waveform as shown in FIG. 1, and the curved shape of the waveform is such that the upper half 11 rotates in the direction of the arrow in FIG. 1, but in the opposite direction. In order not to turn, the shape of the corrugated peak of the lower half 12 is a stopper.
[0018]
Further, the nut 9 has six projecting pieces 8 projecting radially at an equal mutual spacing angle, and its modes are shown in FIGS. In the example of FIGS. 5 and 6, the projecting piece 8 that is curved in the shape of a chevron in cross section is integrally formed around the flat plate 16 to which one surface of the nut 9 is welded. By curving in a dogleg shape in this way, the protruding piece 8 can be strong even if the flat plate 16 is relatively thin.
[0019]
7 and 8, the protrusion 8 is integrally formed around the flat plate 16 to which one surface of the nut 9 is welded. The protrusion 8 is a flat plate. In the case of this example, the flat plate 16 and the protruding piece 8 are made somewhat thicker than those in FIGS.
[0020]
In the example of FIGS. 9 and 10, the projecting piece 8 has a rod shape, and one of them is welded to each of the six side surfaces of the nut 9.
[0021]
In order to repair and reinforce the slope and the inner peripheral surface of the tunnel using such a shear bolt, anchor bolts 7 are planted at appropriate intervals on the surface of the old concrete 1 forming the existing spray layer. The anchor bolt 7 embeds the lock portion 5 in the old concrete 1, but when the nut 6 is turned and moved in the direction of the lock portion 5, pressure is applied to the lock portion 5, and the upper half portion 11, the lower half portion 12, There is a discrepancy, and the discrepancy is locked.
[0022]
Thus, the nut 9 is screwed to the tip of the screw part 4 which protrudes from the surface of the old concrete 1 to the anchor bolt 7 planted in large numbers at appropriate intervals. As a result, the protruding piece 8 protrudes horizontally at the tip of the screw portion 4 in a petal shape.
[0023]
Therefore, the new blowing member 2 is applied on the old concrete 1 so that the nut 9 is completely embedded. As the new spray member 2, mortar or concrete is suitable, and steel fiber reinforced concrete such as SFRC (steel fiber concrete) is particularly suitable.
[0024]
Even if the nut 6 is loosened after the construction, the upper half 11 is engaged with the irregularities 15 of the cut surface 14 of the lower half 12 via the irregularities 15 of the cut surface 13, and the irregularities 15 act as a stopper. Therefore, since it is prevented from returning in the direction opposite to the tightening direction, the lock is not released.
[0025]
Figure 3 is a front view of a main part showing an embodiment of a repair and reinforcement for shear bolts, such as slope and a tunnel inner peripheral surface of the present invention, the basic structure is detailed here because it is similar to the general example described above Although not described in detail, the shape of the irregularities 15 of the cut surfaces 13 and 14 is formed in a sawtooth shape. Also in this case, the shape of the sawtooth is formed in a stepped shape like a ratchet tooth so as to prevent the upper half 11 from returning in the direction opposite to the tightening direction.
[0026]
【The invention's effect】
As described above, the shear bolt for repair / reinforcement of the slope of the present invention or the inner peripheral surface of the tunnel, etc., will not come off even if the nut is loosened after the lock of the anchor bolt is once locked. It is possible to integrate the old concrete and the new spray member with high reliability.
[Brief description of the drawings]
FIG. 1 is a front view of a usage state showing a general example of a repair / reinforcement shear bolt for a slope or an inner peripheral surface of a tunnel according to the present invention.
FIG. 2 is a perspective view showing a general example of a repair / reinforcement shear bolt for a slope of the present invention or an inner peripheral surface of a tunnel.
FIG. 3 is a front view showing a first embodiment of a shear bolt for repairing / reinforcing a slope or an inner peripheral surface of a tunnel according to the present invention.
FIG. 4 is a side view showing a first example of a nut.
FIG. 5 is a plan view showing a first example of a nut.
FIG. 6 is a side view showing a second example of a nut.
FIG. 7 is a plan view showing a second example of a nut.
FIG. 8 is a side view showing a third example of a nut.
FIG. 9 is a plan view showing a third example of a nut.
FIG. 10 is a longitudinal sectional side view showing a conventional example in the case of a slope.
FIG. 11 is a partially longitudinal side view showing a conventional example in the case of a tunnel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Old concrete 2 ... New spraying member 3 ... Stop pin 4 ... Screw part 5 ... Lock part 6 ... Nut 7 ... Anchor bolt 8 ... Projection piece 9 ... Nut 10 ... Cutting part
11 ... Upper half 12 ... Lower half
13 ... Cut surface 14 ... Cut surface
15 ... Roughness 16 ... Plate
17 ... Stopper 20 ... Wire mesh lath

Claims (1)

The outer periphery of the rod-like portion of the lower part of the threaded portion, the inner diameter is provided a locking portion of the slightly larger cylindrical than the outer peripheral surface the diameter of the rod-shaped portion of the bottom of the threaded portion, the mounting nut on the top of the lock portion, a stopper at the lower end In an anchor bolt having a nut, a nut having radial protrusions is screwed into the upper end of the threaded portion, and the upper half and the lower half are formed with a cut portion obtained by cutting the lock portion at an acute angle. In the slope or tunnel, which has stepped irregularities such as ratchet teeth so that the upper half does not return in the direction opposite to the tightening direction. Shear bolts for repairing and reinforcing peripheral surfaces.

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