JPH1046589A - Slope face protective construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently protect a face of slope on a soft natural ground by covering the face of slope with a net body with a PC steel wire knitted in it, arranging a large number of concrete blocks on an upper surface of the net body and tensionally anchoring each of the concrete blocks on an anchor driven in the natural ground of the face of slope. SOLUTION: An anchor hole 18 is drilled on a face of slope 17, the face of slope 17 is covered with a net body 2, grout 19 is injected into the anchor hole 18, and a tension member 8 is inserted. Thereafter, after a large number of concrete blocks 1 are laid on the face of slope 17, the face of slope 17 is tightened by the blocks 1 by tensing an end part of the tension member 8 projected from a tension member insertion hole 9, and then, a ground 17a immediately under the blocks 1 is compressed, and a peripheral ground 17b is expanded. Thereafter, the ground 17b is pressed with the net body 2 by anchoring both end parts by tensing a PC steel wire 10 knitted in the net body 2. Consequently, even when tension of the tension member 8 is released and tightening force of the blocks 1 is lowered, it is possible to protect the face of slope 17 by holding the ground 17b by the net body 2 and the steel wire 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a slope protection method.

[0002]

2. Description of the Related Art In recent years, when planning or constructing a new road in a mountainous area or improving or widening an existing road, a method of protecting a slope with a concrete block has been used as a measure against landslides.

[0003] In this method, a slope is protected by a concrete block fixed with an anchor. However, a relatively soft slope decreases the amount of deformation with time and reduces the introduced anchor force. There was a risk of collapse. Therefore, in order to solve such a problem, as shown in FIG. 8, the slope 22 is covered with a wire net or another net 21 and a number of concrete blocks 23 are arranged thereon, and these concrete blocks 23 are arranged. , The anchor was placed in the ground and the tension was fixed and the slope 22 was protected.

[0004]

However, the method of covering the slope with the net as described above also has a problem that the net is torn or the net is loose and the slope cannot be sufficiently protected. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to reduce an anchor force due to excessive deformation of a slope and to expand and collapse the slope when the slope is weak. It is an object of the present invention to provide a construction method capable of preventing the slope from being prevented.

[0006]

Means for achieving the above object is to cover the slope with a net woven from PC steel wire,
A protective frame is formed by arranging a large number of concrete blocks on the upper surface of the mesh body, and each of the concrete blocks is tensioned and fixed to an anchor cast on the ground of the slope to protect the slope.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the slope protection method will be described below in detail with reference to the drawings. 1 is a plan view of a concrete block for a slope, FIG. 2 is a plan view of a mesh body, and FIG.
1 is a sectional view of a PC steel wire.

In the slope protection method, a concrete block (hereinafter referred to as a concrete block) 1 and a net 2 for the slope as shown in FIGS. 1 and 2 are used.

In the concrete block 1, arms 3 are formed by reinforced concrete so as to protrude in a cross shape, and a tension member 4 is buried in each arm 3 to give a prestress. The arm 3 has a tapered shape, a central portion is formed high and both side portions are formed low, and a connection fitting 5 is protrudingly provided at the tip thereof so that the connection metal 5 can be connected to an adjacent concrete block.

A concave portion 6 is provided at the center of the plane of the concrete block 1, and the concave portion 6 is provided with a tensile material insertion hole 9 for inserting an end of a tensile material 8 fixed to the ground. .

The net 2 as shown in FIG. 2 is formed of a wire net or a synthetic resin material, and PC steel wires 10 are woven at appropriate intervals.

The PC steel wire 10 is a stranded wire obtained by twisting a plurality of side wires 12 around a core wire 11.
A coating inner layer 13 formed by melting and adhering a synthetic resin powder coating is formed on each outer periphery of the first and side lines 12, and a synthetic resin coating middle layer 14 is formed on the outer periphery of the coating inner layer 13 by a synthetic resin extrusion molding means. An outer coating layer 15 made of a synthetic resin is formed on the outer periphery of the coating intermediate layer 14 via a sliding material 16 such as grease in the same manner as described above.

As described above, the PC steel wire 10 has the inner coating layer 13,
Since the coating is performed three times by the coating middle layer 14 and the coating outer layer 15, the rust prevention effect is high, and even if the coating outer layer 15 is broken for various reasons, the stranded wire does not rust.

Next, a slope protection method using the concrete block 1 and the net 2 as described above will be described. First, an anchor hole 18 is excavated while pushing a casing (not shown) into an appropriate portion of the slope 17. This anchor hole 18 is drilled at a position corresponding to the tensile material insertion hole 9 of the concrete block 1 laid on the slope 17.

Next, the net 2 provided with holes corresponding to the anchor holes 18 is covered with the slope 17 and temporarily fixed. At this time, the PC steel wire 10 braided in the net 2 is not tensioned and fixed.

Next, grout 19 is injected from the cement milk into the anchor hole 18 and the casing is pulled out. Then, the tip of the tension member 8 is inserted into the grout 19.

After fixing the tip of the tension member 8 by curing the grout 19, a number of concrete blocks 1 are laid on the slope 17 and the end of the tension member 8 is inserted into the tension member insertion hole 9 of the concrete block 1. The part is inserted and projected from the recessed part 6.

Adjacent ones of the concrete blocks 1 are connected to each other by the connection fitting 5 of the arm 3 to form a protective frame 20 in a lattice shape.

After connecting the concrete blocks 1 to form the protective frame 20 in this manner, the end of the tension member 8 protruding from the tension member insertion hole 9 is tightened with a jack, and is inserted into the recess 6. Establish. When the slope 17 is tightened with the concrete block 1 due to the tension of the tension member 8, the ground 17a immediately below the concrete block 1 is compressed as shown in FIG. 5, but the surrounding ground 17b expands.

In this state, the P woven into the net 2
By stretching the C steel wire 10 and fixing both ends thereof, the expanded ground 17b can be held down together with the net 2.

Therefore, even if the tightening force of the concrete block 1 is reduced due to the loosening of the tension member 8, the ground 17b expanded by the mesh body 2 and the PC steel wire 10 can be pressed.

FIGS. 6 and 7 show a modified example of the mesh 2, and FIG. 6A shows a case where the PC steel wires 10 are woven at a smaller interval than the mesh 2 described above. (2) in the figure shows a PC steel wire 10 woven in a lattice pattern. 7A is a net 2 in which the PC steel wire 10 is woven obliquely, and FIG. 7B is a net 2 in which the PC steel wire 10 is woven obliquely at a small interval. (3) of the same figure
Is a net 2 in which a PC steel wire 10 is woven obliquely in a lattice shape. By weaving the PC steel wire 10 into the net 2 in various ways, the net can be further strengthened.

[0023]

According to the present invention, the slope is covered with a net woven from PC steel wire, a large number of concrete blocks are arranged on the upper surface of the net to form a protective frame, and each of the concrete blocks is cast on the ground of the slope. By protecting the slope by tensioning and fixing to the anchor, the mesh body is reinforced and hardly damaged, and even if damaged, the slope can be sufficiently protected.

Even if the anchor force is reduced due to excessive deformation of the soft slope, the expansion and collapse of the slope can be prevented because the PC steel wire is tensioned and fixed with a predetermined force. Can be sufficiently protected.

[0025] In the PC steel wire, a coating inner layer is formed on each outer periphery of the core wire and the side wire, and the outer periphery of the coating inner layer is covered with a middle coating layer.
Since the outer coating layer is formed on the outer periphery of the intermediate coating layer via a lubricating material, the rust prevention effect is enhanced, and even if the outer coating layer is broken for various reasons, the stranded wire does not rust.

[Brief description of the drawings]

FIG. 1 is a plan view of a concrete block.

FIG. 2 is a plan view of a mesh body.

FIG. 3 is a sectional view of a PC steel wire.

FIG. 4A is a plan view of the slope protection method, and FIG. 4B is a cross-sectional view showing connection of the arm.

FIG. 5 is a sectional view of a slope protection method.

FIGS. 6 (1) and (2) are plan views of another slope protection method.

FIGS. 7 (1), (2) and (3) are plan views of another slope protection method.

FIG. 8 is a plan view of a conventional slope protection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 23 Concrete block 2, 21 Netting 3 Arm part 4 Tensile material 5 Connection metal fitting 6 Depression 7 Anchor 8 Tensile material 9 Tensile material insertion hole 10 PC steel wire 17, 22 Slope

Claims (3)

[Claims] 1. A slope covered with a net woven from PC steel wire, a number of concrete blocks are arranged on an upper surface of the net to form a protective frame, and each of the concrete blocks is cast on the ground of the slope. A slope protection method characterized in that the slope is protected by tensioning and anchoring on the anchor. 2. The slope protection method according to claim 1, wherein the PC steel wire is fixed by being tensioned by a predetermined force. 3. The PC steel wire has a coating inner layer formed on the outer periphery of each of the core wire and the side wire, the outer periphery of the coating inner layer is coated with a coating middle layer, and a coating outer layer is formed on the outer periphery of the coating middle layer with a lubricant interposed therebetween. The slope protection method according to claim 1, wherein the slope is protected.