JP2000297434A - Rockfall prevention method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope therewith even when a change exists in force relation fixing a rock by horizontally stretching a wire rope, and providing a cushioning part expanding the rope between a net part and an anchor bolt when constant or larger tension is applied on the rope formed in the form of a net by connecting an intersection part. SOLUTION: A plurality of wire ropes 1 are horizontally stretched to connect an intersection part so as to form the whole in the form of a net. The rock A of a rockfall prevention object is covered with a net part, and a rope end positioned on the circumference of the net part is connected to an anchor bolt 2 fixed on ground. An intersection connection fitting 3 is used on the formation of the net part, and a cushioning connection fitting 4 is interposed between the anchor bolt 2 and the net part. When the state of the rock A changes and tension of sandwiching friction force or larger by the connection fitting 4 is applied on the rope, the sandwiching part of the rope is moved in a state where constant sandwiching force is held, and the rope is stretched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rock fall prevention method for preventing accidents caused by rock fall on a road.

[0002]

2. Description of the Related Art As a rock fall accident prevention method, there are basically known rock fall protection methods of providing a protection fence or the like so that the rock fall does not directly lead to the accident, and a rock fall prevention method of preventing the occurrence of the rock fall itself. Have been.

[0003] In the latter case, it is basically sufficient to remove floating rocks which may fall, but there are cases where it is impossible to remove them depending on site conditions. Has been proposed and implemented. For example, the foundation and the surroundings of the rock are solidified with concrete to stabilize it, the rock and rock are drilled to the base rock, the rock bolt is fixed to the rock, and the wire rope is wound around the rock and connected to the anchor. Wire rope fixing work to prevent the falling of rocks by connecting with other large stones, etc., a method of injecting adhesive into the rock, a net made of synthetic fiber, wire mesh, wire rope, etc. over the floating stones A coating method and the like are known.

[0004]

In rock fall prevention work, the most appropriate construction method is adopted under the condition of the prevention work, and as described above, the rock fall is achieved by fixing a large stone. Prevention.

[0005] In a natural environment such as an earthquake or heavy rain, the situation in which megaliths are suppressed may change. However, the conventional method only makes the boulder in a fixed state, and therefore can withstand a predetermined overload load even when partially receiving a large load (load due to overload). And rockfall does not occur. However, in the case of a situation change that exceeds the limit of overload bearing, the overload bearing part is not able to withstand and is destroyed and rock falls.

For example, in a wire net method in which a wire rope is formed into a net shape, a net portion is covered with a rock to be rock-fall-prevented, and an end of the rope is connected to an anchor bolt, when a peeling type rock-fall occurs, the rope is instantaneously removed. Large impact force is applied to the cable, the rope may be cut or the anchor bolt may be pulled out, and a situation may occur in which the occurrence of falling rocks cannot be prevented.

Therefore, the present invention proposes a rock fall prevention method of a flexible structure that can sufficiently cope with a change in the force relationship for fixing a megalith due to the surrounding conditions.

[0008]

In the rock fall prevention method according to the present invention, a plurality of wires are stretched vertically and horizontally, and the crossing portions are connected to form a net as a whole. In addition to covering, the rope around the net part is connected to anchor bolts fixed to the ground, and the rope is stretched when a certain amount of tension is applied to the rope. It is characterized in that a buffer part to be performed is interposed between the net part and the anchor bolt.

Accordingly, the rock fall prevention target is covered with the net portion to prevent the rock fall, and even if a change in the situation causes a change in how the force is applied to the net portion, a change in the situation exceeding a predetermined level occurs. Absorption by the elongation of the buffer rope reduces the overload burden.

[0010]

Next, an embodiment of the present invention will be described. <First Embodiment> FIGS. 1 to 8 show a first embodiment of the present invention. In the rock fall prevention device of this embodiment, a plurality of wire ropes 1 are basically stretched vertically and horizontally. An anchor bolt 2 in which the crossing portions are connected to form the whole into a net shape, and the rock A to be rock-fall-prevented is covered with the net portion, and the rope end located around the net portion is fixed to the ground. Net-type rockfall prevention work connected to the bridge, especially adopts a connecting metal fitting 3 for the crossing part used for forming the net part, and a connecting metal fitting 4 for the buffer part interposed between the anchor bolt 2 and the net part. It is characterized by the fact that

The connecting fitting 3 used for the crossing portion is composed of a saddle-like body 31 having an interior portion where the crossing ropes 11 and 12 overlap, a clamping bolt 32 and a nut 33 as shown in FIGS. , The saddle 31 is provided with a rope 1
The crossover portions 1 and 12 can be stored, and the front and lower portions of the storage portion are opened to provide a bolt body mounting opening 311, and a bolt insertion hole 312 is further provided below the rear portion.
The holding bolt body 32 includes a head portion 321 corresponding to the mounting opening 311 and a bolt portion 322 protruding rearward from a lower portion of the head portion 321.

When the bracket 3 is used, the crossing portion of the rope 1 is stored in a state of being superimposed on the storage location (upper portion in the saddle) of the saddle-shaped body 31, and the bolt portion 322 of the holding bolt body 32 is inserted into the insertion hole 312. At the same time, the head 321 is positioned in the mounting opening 311, and the nut 33 is screwed and tightened to the bolt portion 322 protruding from the rear of the saddle-shaped body 31.
12 is sandwiched between the saddle 31 and the head 321 of the bolt 32, and the intersections of the ropes are connected by the metal fittings 3 to form a net as a whole. In particular, since the metal fitting 3 for clamping the rope crossing portion with the clamping force is used,
When a force greater than the gripping frictional force is applied, the gripping portion of the rope moves while maintaining a constant gripping force.

As shown in FIGS. 4, 5, and 6, the shock-absorbing connection fitting 4 includes a receiving body 41, a holding bolt body 42, and a nut 43. The receiving body 41 has a rope storage recess on its upper surface. 411 are formed in parallel with two strips, and a bolt insertion hole 412 is formed between the recessed strips 411. The holding bolt 42
A head 421 having a shape crossing the concave streak 411;
And a bolt portion 422 provided below the middle of the bolt. Then, the rope 13 serving as the end of the net portion and the fastening rope 14 connected to the anchor bolt 2 are respectively positioned in the concave streak 411, and the bolt portion of the holding bolt body 42 is inserted into the insertion hole 412 to project. The nut 43 is screwed and tightened to the bolt portion 422, and the receiving body 41 and the head 421 of the clamping bolt body 42 are tightened.
Thus, the ropes 13 and 14 are clamped with a constant clamping force to connect the net portion and the anchor bolt 2.

Accordingly, the state of the rock A changes and the rope 1
When a tension greater than the clamping frictional force of the connecting fitting 4 is applied to the ropes 3 and 14, the rope 1
The holding portions 3 and 14 move. Rope 1
A stopper fitting 44 is attached to the ends of the ropes 13 and 14 so that the fittings 3 and 14 do not come off the fitting 4 and come off.

Further, for the rock fall prevention and management system, a load comprising a load meter 5 for detecting the tension of the rope at an appropriate number of places between the net portion and the anchor bolt 2 in the above net-covered rock fall prevention work. Insert a sensor. Then, the management system, based on the sensor 5, a conversion unit 6 that converts the information into a predetermined information signal based on the detection data, and a signal (transmitted by wire or wireless such as a telephone line) from the conversion unit 6,
A processing unit (a personal computer, etc.) that performs predetermined processing such as determining the degree of falling rocks, determining whether or not an alarm has been issued, and issuing a warning device.
7. It comprises a predetermined warning unit 8 for notifying danger.

The crossing portions of the wire ropes 1 combined in the vertical and horizontal directions are connected to each other by a crossing connection fitting 3 to form a net, and the net portion is covered with the rock A to be rock-fall-prevented. The ends are fixed to the anchor bolts 2 via the buffer connection fittings 4 to prevent rocks A from falling. In particular, even if the rock A is in a peeling type rock fall state due to an earthquake, heavy rain, etc., the impact force can be absorbed by the slip movement of the connecting metal fittings at three or four places, and the rock A becomes rock fall state. The cutting of the wire rope 1 and the pulling out of the anchor bolt 2 due to the impact force at the time of the occurrence can be suppressed, and the fall of the rock can be prevented.

Further, in a rock falling state or a dangerous state in which the rock shifts to the rock falling state, the tension of the wire rope 1 is increased.
When the detected value is detected by the load sensor 5, the detected value is converted into an appropriate signal and sent to the processing unit 7, the processing unit 7 determines which part of the rock is in a dangerous state, and an alarm device. By operating the warning display device 81 and the warning display device 82 installed on the road, etc., the danger of falling rocks is notified to prevent accidents due to falling rocks. Furthermore, if it is determined based on the detection value of the sensor 5 that at least the possibility of rock fall requires rework of the prevention work, the management of the rock fall prevention work can be easily performed.

Of course, the management system can deal with rockfall management at a single location or at multiple locations as needed.

<Second Embodiment> FIGS. 9 to 16 show a second embodiment of the present invention. The rock fall prevention device of this embodiment is basically the same as the first embodiment described above. Similarly, the cross portion is connected by the cross-connecting metal fitting 3A to form a net portion, the net portion covers the rock A, and the buffer connecting metal fitting 4A is attached to the anchor bolt 2 fixed to the ground. The connection is made, and the rope 13a around the net portion is attached to the connection fitting 4A to hold the rock A on the ground.

The cross-connecting fitting 3A is shown in FIGS.
As shown in the figure, the intermediate body 34 and the two holding bodies 35a, 3
5b, a holding bolt 36 and a nut 37. The intermediate body 34 is a plate-like member having a plane elliptical shape, and grooves 341 and 342 formed on the front and back surfaces in directions intersecting each other.
And bolt holes 343 that penetrate the front and back are formed at both sides of the groove. Clamping body 35a,
The grooves 35b are laminated on the upper and lower sides (front and back) of the intermediate body 34, and the grooves 35b facing the grooves 341 and 342, respectively.
1a and 351b are formed, and bolt holes 352a and 352b corresponding to the bolt holes 343 are formed.

The metal fitting 3A is configured such that a crossing portion of the rope 1 forming a net portion is formed by an intermediate member 34 and holding members 35a, 35b.
Are laminated so as to be sandwiched by the grooves 341 and 351a and the grooves 342 and 351b, respectively, and the bolts 36 are passed through the bolt holes 343, 352a, and 352b in the laminated state, and the nut 37 is screwed and tightened. , Cross rope 11,1
2 is sandwiched between the intermediate body 34 and the sandwiching bodies 35a and 35b, and the rope crossing portions are connected to form a net as a whole. In particular, the connecting fitting 3A for clamping the rope crossing portion with a clamping force.
Therefore, when a force greater than the clamping friction force is applied, the clamped portion of the rope moves while maintaining a constant clamping force.

As shown in FIGS. 13 and 14, the buffer connection fitting 4A includes two holding bodies 45a and 45b, a holding bolt 46, a nut 47, and a hook body 48. The holding body 45a, 45b is a long plate-shaped rope holding groove 451 waved in one surface in the longitudinal direction and in the plate thickness direction.
And a protrusion 453 provided with a hook through-hole (hook body connecting portion) 452 at both ends of the other surface. Further, a bolt hole 454 penetrating the front and back sides is formed on both sides in the longitudinal direction. The hook body 48 includes a holding body 45 facing the holding body 45.
The insertion rod 481 includes a parallel insertion rod 481 penetrating through the hook through holes 452 a and 45b, and a U-shaped portion (hook) 482 connecting the insertion rod 481, and a screw 483 is formed at the tip of the insertion rod 481. Further, a fastening nut 484 screwed into the screw portion 483 is provided.

In order to perform rockfall prevention using the connecting metal fitting 3A for the crossing part and the connecting metal fitting 4A for the buffer part, the crossing parts of the wire rope 1 combined vertically and horizontally must be connected to the crossing fitting metal part. 3A is connected to form a net, and the net formed in the net is covered with rock A to be rock-fall-prevented, and the rope 1
The ends of ropes 1 and 12 (the rope around the net) are 2
Each of the holding bodies 45 is mounted in the facing rope holding groove 451, and the ropes 11 and 12 are held by the holding bolt 46 and the nut 47, and the insertion rod 4 of the hook body 48 is inserted.
81 is inserted into the hook through hole 452, and a fastening nut 484 is screwed into the screw portion 483 to hold the hook body 48 in the holding body 4.
The hooks 48 are connected to 5a and 45b, and the hooks 48 are hooked on the anchor bolts 2 which are fixed to the ground B to hold the rock A. And each rope 1 around the net
When a tension equal to or greater than the clamping friction force of the clamping body 45 is applied to the clamping members 1 and 12, the clamping portions of the ropes 11 and 12 move while maintaining a constant clamping force.

Therefore, even if the rock A is in a peeling type rock fall state due to an earthquake, heavy rain, or the like, the impact force can be absorbed by the slip movement of the wire rope at the connecting fittings 3A and 4A, and the rock A It is possible to prevent the wire rope 1 from being cut or the anchor bolt 2 from being pulled out due to the impact force when the rock falls, thereby preventing the rock from falling. A stopper fitting 49 is attached to the end of each of the ropes 11 and 12 so that the ropes 11 and 12 do not come off from the fitting 4A.

In the second embodiment, the same management system as in the first embodiment can be adopted. That is, a load sensor including a load meter 5 is interposed on a rope around the net portion or other appropriate ropes, and the sensor 5 and a conversion unit 6 that converts a predetermined information signal based on detection data, A processing unit (a personal computer or the like) 7 for performing predetermined processing such as discrimination of a falling rock risk, determination of whether or not an alarm is issued, driving of a warning device, etc., based on a signal from the conversion unit 6; What is necessary is just to provide the part 8.

The second embodiment is different from the first embodiment in that the rope ends are not connected to the anchor bolts 2 in the buffer portion, but are connected to or attached to the anchor bolts 2 for the buffer portion. By connecting to 4A, each rope in the vertical and horizontal directions can be held in a single state,
Adjustment of clamping pressure is easy.

In particular, as shown in FIG. 16, rope play (rope 11
a, 12b) has the advantage that a long rope can be used as it is.

Furthermore, the connecting metal fitting 3A at the crossing portion also holds the vertical and horizontal ropes 11 and 12 separately with metal fittings as compared with the connecting metal fitting 3 of the first embodiment. Has the advantage that it does not rub.
Note that the connection fittings of the first embodiment and the second embodiment can be used in any combination.

[0029]

As described above, the present invention provides a net-cover type rock fall prevention method in which a rock to be protected from rock fall is covered with a wire net and the end of the rope is connected to an anchor bolt. A buffer that extends the rope when a certain amount of tension is applied is interposed between the net and the anchor bolt.Even if the rock falls, the impact force of the rope can be reduced. It is absorbed by elongation, and the cutting of the rope and the detachment of the anchor bolt are further reduced.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a first embodiment of the method of the present invention.

FIG. 2 is an explanatory view of a connection fitting for the crossover portion.

FIG. 3 is a cross-sectional view of the use state of the cross-connecting metal fitting.

FIG. 4 is an exploded perspective view of the connection fitting for the buffer unit.

FIG. 5 is a cross-sectional view of the use state of the shock absorber connection fitting.

FIG. 6 is a plan view of the connection part for the buffer part in a used state.

FIG. 7 is an explanatory diagram of a main part of the management system according to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of the entire management system.

FIG. 9 is an overall plan view of a second embodiment of the method of the present invention.

FIG. 10 is an exploded perspective view of a connection fitting for the crossing portion.

FIG. 11 is a plan view of the use state of the cross-section connecting fitting.

FIG. 12 is a front view of a use state of the cross-connecting member.

FIG. 13 is an exploded perspective view of the connection fitting for the buffer unit.

FIG. 14 is a sectional view of the use state of the shock-absorbing-portion connection fitting.

FIG. 15 is an explanatory diagram of a main part of a management system according to a second embodiment of the present invention.

FIG. 16 is an explanatory view of another example of using the rope of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire rope 2 Anchor bolt 3 Crossover connection fitting 31 Saddle-shaped body 32 Clamping bolt body 33 Nut 3A Crossover connection fitting. 34 Intermediate body 35a, 35b Clamping body 36 Clamping bolt 37 Nut 4 Connection metal fitting for buffer part 41 Receiver body 42 Clamping bolt body 43 Nut 4A Connection metal fitting for buffer part 45 Clamping body 46 Clamping bolt 47 Nut 48 Hook body 5 Load meter (Load meter) Sensor) 6 Conversion unit 7 Processing unit 8 Warning device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshio Kubota 3-14-13 Toriyano, Niigata City Inside Shi Building Co., Ltd. (72) Inventor Hideki Igarashi 1-7-1, Shintoji, Niigata City

Claims (4)

[Claims] 1. A plurality of wire ropes are stretched lengthwise and breadthwise, a crossing portion is connected to form a net as a whole, a rock to be rock-fall-prevented is covered with a net portion, and a rope around the net is grounded. In the cover net type rock fall prevention method connected to the anchor bolt fixed to the rope, when the rope is subjected to a certain amount of tension, a buffer that extends the rope is inserted between the net part and the anchor bolt. Rock fall prevention method characterized by interposition. 2. A receiving body in which two rope storage recesses are formed in parallel on the upper surface, and a bolt insertion hole is formed between the recesses.
An anchor bolt side rope and a net, comprising a clamping bolt body having a head crossing the concave streak and a bolt part provided below the middle of the head and a nut body screwed to the bolt part. The rock fall prevention method according to claim 1, wherein each of the ropes on the section side is connected to form a buffer section. 3. A rope holding groove formed in the longitudinal direction of the opposing surface, a bolt hole formed in both sides in the longitudinal direction, and two clamping bodies having hook body connecting portions on the outer side. A connecting member consisting of a holding bolt and a nut for holding the holding body by pressing and a hook body having a hook portion and a connecting portion for connecting the holding body to each other. The rock fall prevention method according to claim 1. 4. A saddle shape in which the rope crossing portion can be stored inward, a bolt body mounting opening is provided by opening a front portion and a lower front portion of the storage portion, and a bolt insertion hole is provided below the rear portion. A bolt body comprising a head corresponding to the mounting opening and a bolt projecting rearward from a lower part of the head, and a nut body screwed to the bolt of the bolt body. A cross-piece connecting bracket or a plate-shaped member, in which front and back surfaces are formed with grooves formed in directions intersecting with each other, and an intermediate body in which bolt holes are formed at both sides to penetrate the front and back, Two clamping pressure bodies which are laminated on the upper and lower sides of the body and which have the grooves and the bolt holes respectively corresponding to the grooves and the bolt holes, and bolts and nuts which laminate the clamping bodies on the upper and lower sides of the intermediate body to integrate the whole. Any of the cross-connecting fittings consisting of The rock fall prevention method according to any one of claims 1 to 3, wherein a rope crossing portion of the net portion is connected.