JPH08105015A - Protective structure - Google Patents

Abstract

PURPOSE: To increase damping and distributing effects against the impact force of a falling stone. CONSTITUTION: A recessed part 22 is formed in a base 10, and liquid 30 such as water is filled into it. A base plate part 8 is supported on the recessed part 22 through a temporary fixing means 28 provided with a pin 36. Also a roof 3 is provided integrally on the upper part of the base plate part 8. When an impact force is applied to the roof 3 by stone falling, collapse of earth, snowslide, etc., the pin 36 is broken, and the roof 3 is fallen. Then the impact force applied to the roof 3 is reduced by the compression of liquid 30. In addition, because a kinetic energy receiving time of a falling stone becomes large by the falling of the roof 3, an impact force due to kinetic energy held by the falling stone can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective structure such as a shed or a keeper installed to protect roads, railroad tracks, houses and building facilities from falling rocks, landslides, avalanches and the like.

[0002]

2. Description of the Related Art Generally, a structure of this type is constructed by supporting a roof with a support, and a structure made of steel and concrete made of PC or RC is known. For example, a concrete shed is Japanese Utility Model Publication No. 1-4895,
As disclosed in Japanese Patent Publication No. 1-2722,
The main girders, which are multiple concrete wall bodies, are tightly connected together by PC steel materials for lateral tightening facing the longitudinal direction of the road or track to form a roof, and both sides of the roof in the road or track direction are rigidly connected to columns or walls. Is configured. The main girder structure is known to have a T-shaped cross-section or an arch-shaped cross-section, and the main girder support structure is one in which both sides of the main girder are supported by parent and child columns, or a retaining wall. Various things are known, such as those supported by a main pillar or a retaining wall and a retaining wall. A concrete keeper, which is a protective structure of this type, is disclosed in Japanese Utility Model Laid-Open No. 62-196220 and Japanese Patent Publication No. 1-244003.
As is known from Japanese Patent Publication No. JP, etc., a plurality of concrete wall bodies are tightly bound together by PC steel materials for lateral tightening oriented in the length direction of the road or track to form a roof, and this roof is arranged in the road or track direction. It is configured to be installed diagonally on the mountain side, and as this roof support structure, there are known ones that fix the roof to the substructure and pillars, ones that fix the roof to the substructure and the mountain wall.

In these various protective structures made of steel or concrete, the rigidity of the roof and the pillars supporting the same is increased, and the rigidity of the joint between the roof and the pillar is increased, Although it is possible to improve the safety when it receives a rockfall, there is a practical limit to the dramatic increase in the strength of each member in terms of production and cost. Therefore, instead of increasing the strength of each member, for example, Japanese Utility Model Laid-Open No. 62-185708 (Japanese Utility Model Application No. 61-7).
No. 4627), a rubber slag is interposed between a support member, which is a pillar, and a roof structure, and the rubber slag reduces the impact force of rockfall (the same microfilm, p. 6, 8-10). Row) In the shock absorber for rockfall shelters and in Japanese Utility Model Laid-Open No. 57-96209, a hinge is provided at the lower part of a pillar that supports the valley side of the roof (Fig. 6), and this hinge absorbs the subsidence and movement of the ground. It is proposed that the snow protection and protective cover should be adopted.

[0004]

In the case where a rubber slag is partially provided at the joint between the pillar and the roof, like the shock absorber for the rockfall shelter, only the rubber slag portion expands and contracts due to the impact of the rockfall. Therefore, a large buffering effect could not be obtained. Also, in the case where a hinge is provided in the lower part of the pillar like the above-mentioned snow cover and protective cover, it is possible to expect some impact mitigation effect by the hinge, but since only the hinge part is locally deformed, it is buffered. The effect could not be effectively improved.

Therefore, an object of the present invention is to provide a protective structure having an excellent shock absorbing effect.

[0006]

According to a first aspect of the present invention, there is provided a protective structure including a roof which covers at least a part of a road or railroad track along a mountain and is provided along the mountain. A protective structure is provided with a buffer lowering device for lowering the upper surface of the roof when a load larger than a predetermined value is applied due to an avalanche or the like.

According to a second aspect of the present invention, the buffer lowering device supports the roof under the load below a predetermined level and temporarily fixes the roof upper surface when the load is above the predetermined level. 2. A buffer body for enclosing a liquid or gas to receive the load, and a pressure valve means provided in the buffer body to open the liquid or air by opening at a pressure higher than a predetermined value. It is a protective structure.

[0008]

In the structure of claim 1, when an impact force is applied to the roof due to rock fall, landslide, avalanche, etc., the roof is lowered to reduce the impact force.

According to the second aspect of the present invention, when the roof receives rockfall, landslide, avalanche, etc., and a load greater than a predetermined amount is applied to the buffer body and the internal pressure rises above the predetermined value, the pressure valve means is opened, As the liquid or gas escapes, the buffer shrinks and the roof descends. Then, the impact force received by the roof is alleviated by the reduction of the buffer body accompanied by the escape of the liquid or gas, and particularly when a load accompanied by a large impact force is applied by rock fall etc., part of the impact force comes out of the liquid or gas. As the roof is lowered while being converted into kinetic energy, the passive time for receiving the kinetic energy of the rockfall becomes long, so the impact force due to the kinetic energy of the rockfall can be mitigated.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show a first embodiment of the present invention, in which a shock absorbing structure is provided on a roof of a concrete shed, and a plurality of main girders 1 serve as a road M. Alternatively, the laterally tightened PC steel material 2 extending in the longitudinal direction of the track is tightly bound together to form the roof 3 along the mountain Y, and the top surface 3A of the roof 3 receives the falling rock R or the like. Main girder 1
Is pretensioned or post-tensioned by the PC steel material 4 facing the road M or the track width direction, and the pillars 5 and the walls, which are supports on both sides of the roof 3 in the road M or track direction, are support members. 6 and is rigidly connected and integrated by the steel material for vertical tightening 7. Further, the flat plate base plate portion 8 made of concrete in the road M or the track width direction is integrally formed at the bottom portion of the wall 6, that is, the wall. 6 and foundation plate 8
And are integrally formed of concrete, and
The road M is formed on the upper surface of the base plate portion 8, and
The pillar 5 is integrally erected on the upper surface of the base plate portion 8 on the valley T side by PC steel material 9 for vertical tightening to form a shed, and the shed is provided on the foundation 10 between the mountain Y and the valley T. It is provided. Reference numeral 11 in the drawing is a back-filled concrete made of cast-in-place concrete, and a sliding surface 12 is provided between the back-filled concrete 11 and the wall 6.

The buffer lowering device 21 is provided in the lower portion of the base plate portion 8 in this example, and a recess 22 having a plane substantially the same as that of the base plate portion 8 is provided in the base 10, and this recess 22 is formed. It is formed of a steel plate or a concrete plate, and the mountain side and valley side longitudinal side plate portions 24T and 24Y are provided on both sides of the bottom plate portion 23 in the width direction of the road M, and both sides of the bottom plate portion 23 in the road M longitudinal direction. Width direction side plate portions 25, 25 are provided respectively, and the base plate portion 8 is formed so as to be able to move up and down between the side plate portions 24Y, 24T, 25, 25, and further, on the lower surface 8A of the base plate portion 8, Movable legs 26Y and 26T on the mountain side and the valley side are formed on both sides of the road M, respectively.
26T is formed of a steel plate or a concrete plate, and the length dimension of the base plate portion 8 in the longitudinal direction of the road M is substantially equal to that of the base plate portion 8. Further, the end portion 26S of the longitudinal direction of the road M is the width. The side plate portions 25, 25 are in airtight contact with the inner surface sides of the side plate portions 25, 25 via packing or the like (not shown), and the height dimension thereof is formed larger than the height of the recess 22, and the bottom plate portion 23 of the recess 22 is also formed. In the movable leg 26
Elevating guide grooves 27Y and 27T capable of ascending and descending Y and 26T are provided vertically, and movable leg bodies 26Y and 26T are provided in the respective elevator guide grooves 27Y and 27T.
The lower part of the movable leg 26Y is inserted into the up / down guide grooves 27Y, 27T by the temporary fixing means 28 which allows the movable leg 26Y, 26T to descend when a predetermined load is applied to the upper surface 3A.
Y and 26T are fixed, and a plurality of ammunition 29, which are coil springs, are vertically inserted between the lower ends of the movable legs 26Y and 26T and the bottoms of the elevating guide grooves 27Y and 27T. As shown, a buffer 30 is formed by filling a liquid 30 such as water between the lower surface 8A of the base plate portion 8, the recess 22 and the movable legs 26Y and 26T, and the buffer 31 is formed. A plurality of pressure valve means 32 are provided in the movable leg 26T on the valley side which constitutes a part, and a discharge adjusting hole 33 is formed in the movable leg 26T. The pressure valve means 32 is closed by a pressure opening means 34 such as a plug body which is removed when applied, a pressure valve which is opened when a predetermined pressure is applied, or a filter which is broken when a predetermined pressure is applied. Also, the longitudinal side plate on the valley side
A discharge passage 35 formed of a pipe or the like is connected to the 24T, and the discharge passage 35 is embedded in the foundation 10 in a state in which a valley side end of the discharge passage 35 faces the valley T. A temporary fixing member 36 such as a steel bolt or a steel pin is used for the temporary fixing means 28, and the horizontally oriented temporary fixing member 36 is formed on the upper side of the elevating guide grooves 27Y and 27T. The holes 37, 37 and the insertion holes 38 formed in the lower side of the movable leg 26Y are inserted to support at least the load due to the dead weight of the shed, and rock fall R, landslide, avalanche, etc. at the shed installation location. The number and the breaking strength of the temporary fixing member 36 and the like are set according to conditions, and the pressure valve means 32 determines the number and diameter of the discharge adjusting holes 33 according to conditions such as rock fall R, landslide, and avalanche. The number of pressure opening means 34 and the pressure required for opening the pressure opening means 34 are adjusted.

The operation of the above structure will be described below. When the roof 3 receives falling rocks R or the like, a load larger than a predetermined load is applied to the roof 3.
Is applied to the temporary fixing member 36 through the insertion holes 38 of the movable legs 26Y and 26T, the temporary fixing member 36 is broken. In addition, when the load applied to the roof 3 is less than a predetermined value,
The break does not occur. The breakage of the temporary fixing member 36 allows the movable legs 26Y and 26T to descend, and the shed base plate 8 descends along the recess 22. Due to this drop, the pressure of the liquid 30 in the buffer body 31 rises, and when the pressure exceeds a predetermined pressure, the pressure valve means 32 opens. In this case, if the pressure opening / closing means 34 for closing the discharge adjusting hole 33 is a plug, it pops out, and if it is a pressure valve, it opens, and if it is a filter, it breaks and the discharge adjusting hole 33 opens. Then multiple discharge adjustment holes
The liquid 30 in the buffer 31 is discharged from 33 according to the internal pressure, and is discharged from the discharge path 35 to the valley side. The shed further descends as the liquid 30 is discharged, and at the same time, the movable legs 26
Y and 26T compress the bullet 29 against the elasticity of the bullet 29.
In the shed provided with the buffer lowering device 21 that lowers the roof 3 when the shed itself receives a load of a predetermined amount or more as described above, the impact force received by the roof 3 is caused by the temporary fixing means 28 temporarily. The fixing member 36 is broken, and the second shock absorber 31
The liquid 30 is compressed, and thirdly, when the pressure of the liquid 30 rises above a predetermined level due to this compression, the pressure opening means 34 is opened, and fourthly, the liquid 30 is discharged from the discharge adjusting hole 33 according to the pressure of the liquid 30. Fifthly, the ammunition 29 is compressed against its elasticity, and the impact forces applied to the roof 3 are relaxed by these first to fifth. When a load of a predetermined amount or more is applied, the roof 3 descends in the same direction as the falling direction of the falling rocks R and the like,
Passive time to receive the kinetic energy of falling rock R becomes large,
As a result, the impact force applied to the roof 3 by the falling rock R is reduced.

As described above, in this embodiment, in accordance with claim 1, in the protective structure having the roof 3 which covers at least a part of the road M or the railroad track along the mountain Y and is provided along the mountain Y. , Rock fall R, collapsed soil, avalanche, etc., the structure is provided with a buffer lowering device 21 that lowers the upper surface 3A of the roof 3 when a load greater than a predetermined amount is applied. When an impact force is applied to the roof 3 due to an avalanche or the like, the impact force can be effectively alleviated by the roof 3 descending.

As described above, according to the second aspect of the present invention, the buffer lowering device 21 supports the roof 3 under a load below a predetermined level, and receives the load above a predetermined level.
Temporary fixing means 28 for allowing the lowering of the upper surface 3A, a buffer 31 for enclosing the liquid 30 and receiving the load, and a pressure valve means for opening the liquid 30 by opening the buffer 30 by a pressure higher than a predetermined value. Since the roof 3 has 32 and 32, the roof 3 has a falling rock R,
When a load greater than a predetermined value is applied to the buffer body 31 and the internal pressure rises above a predetermined level due to landslide, avalanche, etc., the pressure valve means 32 opens and the liquid 30 or gas inside escapes.
31 shrinks and roof 3 descends. Then, the impact force received by the roof 3 is effectively alleviated by the reduction of the buffer body 31 accompanied by the escape of the liquid 30 or the gas, and particularly when a load accompanied by the impact force is applied by the rockfall R or the like, a part of the impact force is applied. Since the passive time to receive the kinetic energy of the rockfall R becomes long as the roof 3 descends while being converted into the kinetic energy of the liquid 32 or the gas that escapes, the impact force that the roof 3 receives due to the kinetic energy of the rockfall R. Can be effectively mitigated.

Further, as an effect of the embodiment, the temporary fixing means 28
Is a temporary fixing member consisting of steel bolts and steel pins.
Using a horizontal fixing member 36,
The through holes 37, 37 formed on the upper side of the 27Y, 27T and the through hole 38 formed on the lower side of the movable leg 26Y are inserted to support at least the load due to the weight of the shed, and the load is less than a predetermined amount for the roof. 3, the temporary fixing member 36 is configured to be broken when a load larger than a predetermined value is applied, so that a part of the load can be absorbed by the breaking.
Further, by setting the number of temporary fixing means 28 and the breaking strength of the temporary fixing member 36 and the like, it is possible to obtain a supporting strength suitable for conditions such as rock fall R, landslide, and avalanche. Further, the pressure valve means 32 includes a movable leg 26 that constitutes a part of the buffer 31.
A discharge adjusting hole 33 is formed in T, and a pressure opening means 34 such as a plug body that is removed when a predetermined pressure is applied, a pressure valve that is opened when a predetermined pressure is applied, or a filter that is broken when a predetermined pressure is applied to the discharge adjusting hole 33. Since the pressure valve means 32 is provided by being closed by the above, the liquid 30 inside the buffer body 31 is compressed to a predetermined pressure until the shed falls upon receiving the rockfall R and the pressure opening means 34 is opened. The force can be relieved, and when opened, the impact force is relieved by discharging liquid 30, etc.,
Also, by adjusting the number and diameter of the discharge adjusting holes 33, it is possible to obtain a cushioning structure suitable for conditions such as rock fall R, landslide, and avalanche. Furthermore, by providing an ammunition 29 that is compressed by the descent of the roof 3, the cushioning effect of this ammunition 29 reduces the impact force of the roof 3 even if it receives falling rocks R after the descent. The shed descends until the lower surface 8A of the base plate portion 8 comes into contact with the bottom plate portion 23 of the recess 22, but at the time of the contact, the ammunition 29 serves as a cushion, so that a vehicle passing through the road M or the like is passed. It is possible to suppress the impact given to the like. The shed has a roof 3 and pillars 5.
Since the wall 6 and the base plate portion 8 are integrally formed into a substantially box shape, the strength is excellent and the buffer lowering device 21 can be effectively operated.

FIG. 5 shows a second embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. 21A
Is the lower surface 8A of the base plate portion 8, the recess 22 and the movable leg 26.
An elastic sealing bag 31A having substantially the same shape as the space is inserted and arranged in a space surrounded by Y and 26T, and the liquid 30 or gas is enclosed in the elastic sealing bag 31A serving as a buffer. The elastic hermetically sealed bag body 31A is formed by forming an elastic sheet having elasticity such as rubber into a bag shape. In this example, the liquid 30 such as water is enclosed therein, and the elastic hermetically sealed bag body 31A has , A plurality of pressure valve means 32A are provided.
32A has a discharge adjusting hole 33A formed in the elastic sealed bag 31A,
The discharge adjusting hole 33A is closed by the pressure opening means 34 such as a filter which is broken when a predetermined pressure is applied to form a pressure valve means 32A. Also in the following embodiments, the elastic sealing bag body is made of the same material as the elastic sealing bag body 31A.

When the roof 3 receives rockfall R or the like and a load larger than a predetermined value is applied to the roof 3, a shearing force is applied to the temporary fixing member 36 through the insertion holes 38 of the movable legs 26Y and 26T, and the temporary fixing member 36 is subjected to the shearing force. The fixing member 36 breaks. The breakage of the temporary fixing member 36 allows the movable legs 26Y and 26T to descend, and the shed base plate 8 descends along the recess 22. Due to this drop, the pressure of the liquid 30 in the elastic sealing bag 31A rises, and when the pressure exceeds a predetermined pressure, the pressure valve means 32 opens and the liquid inside
30 is discharged and the impact force applied to the roof 3 is relieved.

As described above, in this embodiment, the buffer body is the elastic sealing bag body 31A, and the elastic sealing bag body 31A has pressure valve means.
32A is provided, and according to claims 1 and 2,
In this example, the cushioning body is made of rubber or the like and has an airtight elastic sealing bag body 31A, which has the same operation and effect as the first embodiment. Since it becomes suitable for enclosing the gas, and the inside is gas when the pressure valve means 32A is opened, it is quickly discharged, so that when the rockfall R etc. is received, the descending speed of the roof 3 is made relatively fast. Therefore, the passive time at the rockfall R can be increased. Since the ammunition 29 is installed even if the descending speed becomes relatively fast,
The impact when the base plate portion 8 contacts the bottom plate portion 22 can be mitigated.

FIG. 6 and FIG. 7 show a third embodiment of the present invention, in which the same parts as those of the above-mentioned embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. And the roof 3 and the walls 6 and the roof 3 are provided with trough-side and mountain-side buffer lowering devices 21B and 21C, respectively. The trough T-side buffer lowering device 21B is the valley of the roof 3. A square tube-shaped movable leg body 39 which is externally fitted to the upper portion of the pillar 5 is fixed to the side lower surface,
The movable leg 39 made of this steel plate or concrete plate is fitted on the upper part of the pillar 5 and fixed by a temporary fixing means 40 which allows the movable leg 39 to descend when a predetermined load is applied,
An elastic sealing bag body 31B as a buffer is housed in the movable leg body 39, a liquid 30 such as water or a gas is sealed in the elastic sealing bag body 31B, and the pressure valve means 32A is contained in the elastic sealing bag body 31B.
Is provided. The temporary fixing means 40 fixes a temporary fixing member 36A such as an anchor bolt in an insertion hole 41 formed in the movable leg 39 and a fixing hole 42 formed in the column 5, and at least the roof is fixed by the temporary fixing member 36A. The roof side load is supported by its own weight, the roof 3 is supported by a load less than a predetermined value, and the roof 3 is allowed to descend when a load more than a predetermined value is received. 21C for the buffer lowering device on the mountain side
Has a movable leg 43 made of a steel plate or a concrete plate fixed to the lower surface of the roof 3 on the mountain side. The movable leg 43 has a long plate shape that is long in the longitudinal direction of the road M, and on the valley side surface of the wall 6, A guide plate 44 having a substantially L-shaped cross section is fixed to form a guide groove 45 inside the guide plate 44, and the movable leg 43 is formed along the guide groove 45.
In the state shown in FIG. 6, the lower end side of the movable leg body 43 is inserted into the upper portion of the guide groove 45 in a press-fitted state, and the movable leg body 43 is inserted into the wall 6. The movable leg
It is fixed by a temporary fixing means 46 that allows the descent of 43, and an elastic sealing bag body 31C as a buffer is housed between the step portion 6A formed on the upper valley side of the wall 6 and the lower surface of the roof 3 and the elastic The sealing bag 31C can be formed in a bag shape that is long in the longitudinal direction of the road M, or can be formed into a shape that is divided into a plurality of parts in the longitudinal direction by a predetermined length, and liquid such as water can be stored in the elastic sealing bag 31C. 30 or a gas is sealed, and the elastic sealing bag 31C is provided with the pressure valve means 32A. The temporary fixing means 46 includes an insertion hole 47 formed in the movable leg 43 and a fixing hole 48 formed in the wall 6.
Secure the temporary fixing member 36A such as an anchor bolt to
At least the mountain side load of the roof 3 is supported by the temporary fixing member 36A, the roof 3 is supported at a load less than a predetermined value, and the roof 3 is allowed to descend when a load of a predetermined value or more is received. In this example, the wall 6 and the backfill concrete 11 are integrated without providing a sliding surface. Next, the operation of the above configuration will be explained. Is applied to the roof 3, a shearing force is applied to the temporary fixing member 36A through the insertion holes 41 and 47 of the movable legs 39 and 43, and the temporary fixing member 36A is fixed to the fixing hole.
It falls off or breaks from 42 and 48. If the load applied to the roof 3 is less than the predetermined value, the fracture does not occur.
When the temporary fixing member 36A falls off or is broken, the movable legs 39 and 43 are allowed to descend, and the roof 3 descends. Due to this drop, the pressure of the liquid 30 in the buffers 31B and 31C rises, and when the pressure exceeds a predetermined pressure, the pressure valve means 32A opens. Then, the liquid 30 in the bags 31B and 31C is discharged from the discharge adjusting hole 33 according to the internal pressure. The movable legs 39,
The 43 may be provided with a discharge hole (not shown) for discharging the liquid 30 or the gas, if necessary.

As described above, in this embodiment, in accordance with claim 1, in the protective structure provided with the roof 3 which covers at least a part of the road M or the railway track along the mountain Y and is provided along the mountain Y. , Falling rocks R, landslides, avalanches, etc., are protective structures that are equipped with buffer lowering devices 21B, 21C that lower the upper surface 3A of the roof 3 when a load greater than a predetermined value is applied. When an impact force is applied to the roof 3 due to landslide, avalanche, etc., the roof 3 is lowered and the impact force can be effectively mitigated.

As described above, in this embodiment, in accordance with the second aspect, the buffer lowering devices 21B and 21C support the roof 3 under a load lower than a predetermined value, and when the load exceeds a predetermined value, the roof 3 moves. Temporary fixing means 40, 46 allowing the lowering of the upper surface 3A
And elastic sealing bag members 31B and 31C that are buffers that contain the liquid 30 or gas and receive a load, and these elastic sealing bag members 31B and 31C.
Since the roof 3 is provided with the pressure valve means 32A, 32A which is opened at a predetermined pressure or more to release the liquid 30 or the gas, the roof 3 is subjected to rockfall R, landslide, avalanche, etc. When a load more than a predetermined amount is applied to 31B, 31C and the internal pressure rises more than a predetermined amount, the pressure valve means 32A, 32A are opened, the liquid 30 or the gas inside escapes, and the elastic sealing bags 31B, 31C shrink and the roof. As 3 descends,
The impact force received by the roof 3 is effectively alleviated, and the same action and effect as those of the first embodiment are obtained, and the elastic sealing bag 31B,
By using 31C, the same effect as the effect of the second embodiment can be obtained.

FIG. 8 shows a fourth embodiment of the present invention. The same parts as those in the above-mentioned embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. In addition to the configuration of the example, using an ammunition, the elastic sealed bag body 31
Horizontal elevating plates 49T and 49Y are provided below B and 31C, and a bullet 50T such as a coil spring is arranged between the elevating plate 49T and the upper surface of the pillar 5, and the elevating plate 49Y and the stepped portion 6A are arranged. A plurality of ammunition 50Y such as coil springs are arranged between the upper surfaces.

The shock absorber lowering devices 21B and 21C of this example also act on the rockfall R in the same manner as in the above-described three embodiments, and in addition, the shock absorbers 50Y and 50T having elasticity to resist the compressive force act as a shock absorber. The effect can be enhanced, and the impact of the lowering of the roof 3 when the lower surface of the roof 3 hits the pillar 5 and the step 6A can be mitigated by the cushioning effect of the ammunition 50Y, 50T.

FIG. 9 shows a fifth embodiment of the present invention, in which the same parts as those in the above-mentioned embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. An elastic sealing bag body 51 for enclosing the liquid 30 or gas to be the buffer lowering device 21D is provided, and the upper surface portion of the elastic sealing bag body 51 constitutes the upper surface 51A of the roof 3 for receiving falling rocks R and the like. The elastic sealing bag body 51 is formed to have a width larger than the width of the roof 3 in the width direction of the road M, and the bag body 51 has a plurality of pressure valve means 32A.
Is provided on the valley side, and a liquid 30 such as water or a gas is enclosed therein.

When the upper surface 51A of the roof 3 receives a falling rock R or the like, the upper surface 51A descends due to elastic deformation of the elastic sealing bag body 51, the pressure of the liquid 30 or gas inside rises, and a load of a predetermined amount or more is received, When the pressure rises above a predetermined level, the pressure valve means 34
The liquid 30 or gas inside is discharged through the discharge adjusting hole 33, and the impact force of the rock fall R or the like is firstly elastically deformed by the elastic sealing bag body 51 in which the liquid 30 or gas is sealed, and secondly. It is absorbed and relaxed by the discharge of the liquid 30 or gas after the pressure valve means 34 is opened.

As described above, in this embodiment, in accordance with claim 1, in the protective structure provided with the roof 3 which covers at least a part of the road M or the railway track along the mountain Y and is provided along the mountain Y. , Falling rock R, collapsing soil, avalanche, etc., is a protective structure that is provided with a buffer lowering device 21D that lowers the upper surface 51A of the roof 3 when a load greater than a predetermined amount is applied. When an impact force is applied to the roof 3 due to an avalanche or the like, the upper surface 51A of the roof 3 is lowered and the impact force can be effectively mitigated. Further, in this example, since the pressure valve means 32A is provided facing the valley side, the liquid 30
In the case where the liquid is filled, there is no possibility that the road 30 is contaminated by the liquid 30.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, the protective structure can be applied to various types. Further, although the example in which the protective structure is provided between the mountain and the valley is shown in the embodiment, the present invention is also applicable to the protective structure provided between the mountain and the flat ground. Furthermore, when the protective structure is installed in a cold region, it is preferable to use an antifreeze liquid in order to prevent the liquid from freezing in winter and the like. Furthermore, in the third embodiment, the mountain side of the roof may be supported by a pillar, and the buffer lowering device 21B may be provided between the mountain side pillar and the roof.

[0028]

According to the invention of claim 1, in a protective structure having a roof which covers at least a part of a road or railroad track along a mountain and is provided along the mountain, a predetermined structure is caused by rockfall, landslide, avalanche, etc. A protective structure which is provided with a cushioning lowering device for lowering the roof top surface when receiving the above load, and can provide a protective structure excellent in cushioning force of impact force.

According to a second aspect of the present invention, the buffer lowering device supports the roof under the load of a predetermined value or less and allows temporary lowering of the roof upper surface when receiving a load of the predetermined value or more. 2. A buffer body for enclosing a liquid or gas to receive the load, and a pressure valve means provided in the buffer body to open the liquid or air by opening at a pressure higher than a predetermined value. It is possible to provide a protective structure excellent in impact buffering effect.

[Brief description of drawings]

FIG. 1 is a sectional view of a protective structure showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view in which a part of the buffer lowering device according to the first embodiment of the present invention is cut away.

FIG. 3 is an enlarged cross-sectional view of a main part of the buffer lowering device according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating the operation when falling rocks according to the first embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view of a main part of a buffer lowering device showing a second embodiment of the present invention.

FIG. 6 is a sectional view of a protective structure showing a third embodiment of the present invention.

FIG. 7 is an exploded perspective view of a buffer lowering device according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a protective structure showing a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a protective structure showing a fifth embodiment of the present invention.

[Explanation of symbols]

 3 Roof 3A Upper surface 21 21A 21B 21C 21D Buffer lowering device 28 40 46 Temporary fixing means 31 Buffer 31A 31B 31C 51 Elastic sealing bag (buffer) 32 32A Pressure valve means 51A Upper surface

Claims (2)

[Claims] 1. A protective structure having a roof that covers at least a part of a road or railroad track along a mountain and is provided along the mountain when the load exceeds a predetermined value due to rock fall, landslide, avalanche, etc. A protective structure characterized by being provided with a buffer lowering device for lowering the upper surface of the roof. 2. The buffer lowering device supports the roof under the load equal to or lower than a predetermined value, and temporarily fixes means for allowing the roof top surface to descend when receiving a load equal to or higher than the predetermined value, and a liquid or a gas. A buffer body that is enclosed and receives the load,
2. The protective structure according to claim 1, further comprising: pressure valve means provided on the buffer body and opened by a pressure of a predetermined value or more to allow the liquid or air to escape.