JP5859682B2 - Protective embankment - Google Patents

Description

  The present invention relates to a protection dam body that receives and protects rockfalls, landslides, and avalanches.

Patent Document 1 discloses a protective bank body that receives a huge impact such as falling rocks. This protective levee was constructed by repeating a hierarchical embankment and a laying of embankment reinforcement that embeds embedding reinforcement such as geotextile into the embankment to construct a embankment with a trapezoidal cross section. It has a structure in which the entire receiving surface on the mountain side is covered with a hard lining material such as a concrete panel.
In Patent Documents 2 and 3, the mountain-side receiving surface of the embankment embankment is covered with a cushion layer formed by filling a resin frame having a plurality of cells filled with fillers such as granular materials and earth and sand. A protective dam body is disclosed.
The protection dam body of patent documents 2 and 3 attenuates an impact by local plastic deformation of a cushion layer.

JP 2010-255200 A JP 2011-47162 A Japanese Patent Application Laid-Open No. 2011-20296

The above-described conventional protective bank body has the following problems.
<1> The protective levee body of Patent Document 1 has a problem that a concrete hard lining material is destroyed at the time of impact and a problem that the cost of the hard lining material increases.
<2> When the hard lining material is a plurality of concrete panels, the impact that has acted on some of the panels cannot be transmitted to a wide area of the receiving surface of the embankment bank.
Therefore, it is necessary to make the embankment body large enough to withstand impacts acting locally.
<3> The protective dam body of Patent Document 2 cannot transmit an impact that has acted on a part of the cushion layer over a wide range of the receiving surface of the embankment dam body.
<4> In the cushion layer described in Patent Document 2, a plurality of frames are stacked in a step shape, and a part of the upper mouth of each frame is opened.
Therefore, the cushioning performance of the cushion layer is reduced because the filling material in the cushion layer jumps out to the outside through the upper opening opened at the time of impact.
<5> In the protective dam body of Patent Document 2, when a plurality of falling rocks collide, there is a risk that the cushion layer is destroyed as the cushioning function of the cushion layer decreases.
<6> The protective bank body of Patent Document 2 forms the embankment bank body as a large structure in order to enhance the protection performance.
If the supporting ground of the levee body is weak and the bearing strength is insufficient, it is necessary to improve the ground, increasing the burden in terms of both construction cost and construction period.
<7> In the recent severe economic environment, not only cost reduction but also miniaturization of protection levee body and high performance are required, but suitable technology that satisfies these multiple requirements is still not available. Not proposed.

  The present invention has been made to solve the above-mentioned problems. The object of the present invention is to reduce the cost, widen the transmission range of the impact and improve the protection performance, and reduce the size of the dam body. It is to provide a protective embankment that can be paralleled.

The present invention is a protective levee body comprising a levee body body having a receiving surface, and a semi-hard buffer restraint layer covering the receiving surface, wherein the dam body body is composed of a reinforced embankment body, The buffer constraining layer is composed of a plurality of impact bodies in which a hard cushion material is accommodated in a horizontally long restraint so that the load can be transmitted between adjacent impact bodies. The buffer constraining layer is provided with an uneven pressing surface in which a part of the hard cushioning material protrudes from the back surface toward the receiving surface of the levee body main body, and the buffer constraining layer has an uneven pressing surface. And a surface of the receiving surface of the levee body deformed into an uneven shape corresponding to the uneven pressing surface, a suction restraining sheet is interposed, and the buffer restraint layer whose hardness changes from semi-rigid to hard when received The shock acting on the buffer constraining layer is distributed and transmitted to the main body of the dam body via the.
In particular with a protective for embankment of the present invention, as the uneven pressing surface to receive撃時to pressure deform the受撃surface of the dam body, relationship bringing the size of the back of the opening and the hard cushioning material of the restraining cage It has been.
Furthermore, the opening on the front surface of the restraint rod is formed smaller than the opening on the back surface of the restraint rod.
Further, the reinforced embankment body comprises a plurality of embankment layers constructed in a hierarchical manner by contacting the uneven pressing surface of the impactor via a suction prevention sheet, and embankment reinforcements laid between the embankment layers. Is doing . Furthermore, the cross section of the impactor is a square.
By constructing the levee body with a reinforced embankment body, familiarity with the buffer restraint layer is improved, and the dam body can be manufactured at low cost.
When the adjacent receiving bodies are connected together by using the connecting material and the reinforcing connecting material, the transferability of the load in the buffer restraint layer is improved.

The protective dam body of the present invention is provided with a buffer restraint layer whose hardness changes from semi-rigid to hard when received, thereby reducing the cost, widening the transmission range of the impact, improving the protection performance, Miniaturization of the body can be paralleled.
Furthermore, in the present invention, the uneven pressing surface is formed on the back surface of the semi-rigid buffer restraint layer, so that the contact area between the dam body main body and the buffer restraint layer is greatly increased, and the uneven press surface at the time of impact is By hardening the surface layer of the impact surface, the shock dispersion and transmission performance between the buffer restraint layer and the main body is remarkably enhanced.

The perspective view which abbreviate | omitted a part of the protection bank body concerning this invention Cross section of protective embankment Perspective view of restraint rod This is an explanatory diagram of the protective dam body, and a model diagram when constructing the first-stage impactor This is an explanatory diagram of the protective dam body and is a model diagram when building the first level embankment layer This is an explanatory diagram of the protective dam body, and a model diagram when constructing the second-stage impactor This is an explanatory diagram of the protective embankment, and a model diagram when constructing the second level embankment layer Horizontal cross section of protective dam body to explain the action of the protective dam body Front view of the buffer constraining layer with a part omitted in the explanatory diagram of the form in which the impacting bodies are connected with the reinforcing connecting material It is explanatory drawing of the form which gave the slope to the receiving surface of the mountain side of a protection levee, (a) is sectional drawing of the protection dam body which a part was abbreviate | omitted, (b) is bb of (a). Cross section Cross-sectional view of the protective levee with a part omitted from the explanatory view of the sloped surface of the receiving surface on the mountain side of the protective dam

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1> Outline of protective dam body Referring to FIGS. 1 and 2, the protective dam body 10 according to the present invention covers the dam body body 20 and the receiving surface 20b on the mountain side of the dam body body 20. A semi-rigid buffer constraining layer 30 is used. The buffer constraining layer 30 has a characteristic that its hardness increases when it receives an impact, and the shock can be distributed and transmitted through the buffer constraining layer 30 over a wide area.
In particular, in the present invention, the uneven pressing surface 37 is formed on the back surface of the semi-hard buffer restraint layer 30, and the receiving surface 20 b of the dam body 20 is formed into an uneven shape corresponding to the uneven pressing surface 37. Thus, the contact area between the dam body main body 20 and the buffer restraint layer 30 is increased, and the uneven pressing surface 37 hardens the surface layer of the receiving surface 20b at the time of receiving, whereby the buffer restraint layer 30 and the dam body main body 20 are The dispersive and transferability of the shock between the two becomes much higher.

<2> Levee Body Main Body The dam body body 20 is a resistor having a substantially trapezoidal cross section that receives impacts such as falling rocks.
In this example, a plurality of embankment layers 21 in which the main body 20 is hierarchically constructed, a sheet-like embankment reinforcing material 22 laid between the embankment layers 21, and a back surface 20 a on the inclined valley side of the embankment layer 21 are covered. Although the case where it comprises with the reinforced embankment body which has the wall surface material 23 is demonstrated, a well-known dam body structure can be applied if it is a gravity type resistance body with small hardness compared with the buffer restraint layer 30. FIG.
Although this example shows a case where the mountain-side receiving surface 20b of the levee body main body 20 is formed vertically, a gradient may be imparted to the mountain-side receiving surface 20b.

<2.1> Embankment Reinforcement Material The embankment reinforcement material 22 is a reinforcing member for increasing the shear resistance and bending resistance of the dam body body 20, and a known mesh-like material having a high tensile strength typified by a geogrid can be used. .
The connection relationship between the embankment reinforcing material 22 and the buffer restraint layer 30 may be an integral structure or a separate structure. When one end of the wall material 23 is connected to the buffer constraining layer 30 and integrated, the connection strength between the dam body main body 20 and the buffer constraining layer 30 is increased, and the stability of the buffer constraining layer 30 is improved.

<2.2> Wall Material The wall material 23 that protects the slope of the levee body 20 is formed by bending a rectangular expanded metal, a welded wire mesh, a woven wire mesh, a perforated steel plate, etc. into a substantially L-shaped cross section, A reinforcing diagonal member 23a is disposed between the horizontal portion and the upright portion.
Moreover, a known suction prevention sheet, a greening sheet, etc. are attached inside the wall surface material 23 as needed.

<3> Buffer Constraint Layer The buffer constraint layer 30 is composed of a plurality of horizontally long receiving bodies 35 having a square cross-sectional shape, and the plurality of receiving bodies 35 are stacked vertically and horizontally to receive the mountain-side receiving surface of the dam body body 20. 20b is coated.
The impact body 35 is normally semi-rigid and has a property of increasing its hardness when received.
In the present invention, “semi-rigid” refers to a state in which a certain range of bending deformation and consolidation deformation are allowed.

<3.1> Impactor The impactor 35 is attached to the inside of the restraint rod 31, a plurality of oblong restraint rods 31 having a square cross section, the hard cushioning material 32 sealed in the restraint rod 31 so as to be restrained. The suction-preventing sheet 33 is provided, and a concave and convex pressing surface 37 is formed by projecting a part of the hard cushioning material 32 on the back surface of the impactor 35. The suction prevention sheet 33 may be omitted.

<3.2> Restraint rod FIG. 3 shows an example of the restraint rod 31. The restraint rod 31 has a bottom panel 31a having a horizontally long rectangle, a front panel 31b and a back panel 31c erected on a pair of long sides of the bottom panel 31a, and one or both sides of a pair of short sides of the bottom panel 31a. And an end face panel 31d.
In addition, a partition panel (not shown) having the same shape as the end face panel 31d may be additionally installed in the middle portion of the restraint rod 31.

The restraint rod 31 has a strength that does not easily break when a falling rock collides, and is formed, for example, by combining various wire meshes, expanded metal, perforated steel plates, or the like. The material is not limited to metal, but may be formed of a resin net-like material having excellent weather resistance and tensile strength.
Moreover, as the restraint rod 31, it is also possible to divert a well-known futon rod, mesh box, and gabion used for revetment.

  The opened upper mouth of the restraint rod 31 is closed with a dedicated lid 31e, or the bottom surface 31a of the upper restraint rod 31 is also used as a lid.

<3.2.1> Reason for restraining the hard cushioning material In the present invention, the hard cushioning material 32 is sealed in the restraint rod 31 so as to be restrained.
The reason for this is to prevent the hard cushioning material 32 from popping out and to lock when the compaction deformation of the hard cushioning material 32 reaches the limit, while maintaining the shape of the impacting body 35. This is to change the hardness from semi-hard to hard.

<3.2.2> Reason why the restraint rod is formed horizontally The reason why the restraint rod 31 is formed horizontally is to extend the impact transmission area through the impactor 35 toward the extension direction of the dam body 20. It is.

<3.2.3> Dimensional relationship between opening of back panel and hard cushioning material In the present invention, not only the hard cushioning material 32 is enclosed in the restraint rod 31 so as to be restrained but also on the rear panel 31c side of the restraint rod 31. An uneven pressing surface 37 is formed by projecting a part of the hard cushioning material 32 to the outside.
The opening size of the back panel 31c of the restraint rod 31 and the hard cushioning material so that a part of the hard cushioning material 32 protrudes to the outside through the opening of the rear panel 31c and can form the uneven pressing surface 37 on the rear surface of the impactor 35. 32 sizes are related.
In other words, both the front panel 31b and the back panel 31c of the restraint rod 31 have an opening size smaller than the maximum diameter of the hard cushioning material 32 so that the passage of the hard cushioning material 32 can be prevented. The opening dimensions allow a part of the hard cushioning material 32 to protrude.
More preferably, the opening size of the front panel 31b of the restraint rod 31 is made smaller than the opening of the back panel 31c. When the opening size of the front panel 31b is set in this way, the hard cushioning material 32 can be reliably prevented from jumping out from the front surface of the restraint rod 31 at the time of impact.

<3.3> Hard cushioning material As the hard cushioning material 32, hard granular materials, such as a stone, crushed stone, and artificial granulated material, can be used. Considering the buffer performance, a single granular hard granule is desirable.

[Construction method]
Next, a construction method of the protective dam body 10 will be described with reference to FIGS.

<1> Construction of the lowest impact body As shown in FIG. 4A, a plurality of restraint rods 31 are arranged in a horizontal row on the mountain side of the installation site, and a connecting material such as a coupling coil is provided between adjacent restraint rods 31. Link.
After the suction prevention sheet 33 is provided in each restraint rod 31 with only the upper opening opened, a hard cushioning material 32 of a predetermined size is filled to form the lowermost receiving body 35.
When the hard cushioning material 32 is filled in the restraint rod 31, a part of the hard cushioning material 32 protrudes to the outside through the opening of the rear panel 31 c, and the uneven pressing surface 37 is formed on the rear surface of the impactor 35.

<2> Construction of the lowest fill layer Laying the fill reinforcing material 22 horizontally on the back side (valley side) of the lowermost impact body 35, and the wall material 23 at the end (right end) of the fill reinforcing material 22 Mount and fix the fixed pin 24 by driving.
The bottom sediment layer 21 reaching the height of the lowermost receiving body 35 is constructed by rolling out the earth and sand on the embankment reinforcing material 22 and rolling it. When the embankment layer 21 is rolled, the embankment on the receiving surface side is pressed against the uneven pressing surface 37 of the receiving body 35 to be formed into an uneven shape.
A separate suction prevention sheet 25 is disposed between the back surface of the lowermost receiver 35 and the embankment layer 21 to prevent the embankment sand from being sucked out.
FIG. 4B shows a form in which the embankment layer 21 is constructed on the back surface of the lowermost receiving body 35.
In constructing the embankment layer 21, the impactor 35 and the wall surface material 23 prevent free movement of the earth and sand, so that the embankment layer 21 can be reliably rolled.

<3> Construction of second-stage and subsequent impact bodies and embankment layer As shown in FIGS. 4C and 4D, the same process as described above with the second-stage impact body 35 directly above the lowermost-stage impact body 35. In addition, the second-stage embankment layer 21 is extended directly above the lowermost embankment layer 21 using the embankment reinforcement 22 and the wall surface material 23.
In constructing the second-stage impactor 35, the upper end of the lowermost-stage impactor 35 is closed with the bottom surface 31a of the second-stage restraint rod 31, or the lowermost-stage impactor 35 is received with a dedicated lid 31e. The upper mouth of the body 35 is closed and the hard cushioning material 32 is enclosed in a restrainable manner.
In addition, the lower and second impact bodies 35 are connected by a connecting member 34 so that a load can be transmitted.
Thereafter, the above-described operation is repeated, and the dam body main body 20 made of a reinforced embankment body having an uneven receiving surface 20b as shown in FIG. 2 and a semi-rigid buffering constraint in which an uneven pressing surface 37 is formed on the back surface. A protective embankment 10 having a layer 30 is constructed. The upper opening of the uppermost receiver 35 is closed with a dedicated lid 31e.

[Operation of protective embankment]
<1> Before Impact Action As shown in FIG. 2, the semi-rigid buffering restraint layer 30 covers the mountain-side receiving surface 20 b of the bank body 20. Further, the receiving members 35 adjacent to each other in the vertical and horizontal directions constituting the buffer restraint layer 30 are connected by a connecting member 34 so that a load can be transmitted.
The uneven pressing surface 37 of the buffer restraint layer 30 and the receiving surface 20b of the bank body 20 are in contact with each other in a familiar state.
Before the impact action, the buffer restraint layer 30 is in a semi-rigid state.

<2> Impact Attenuating Action FIG. 5 shows a horizontal cross section of the mountain side of the protective dam body 10 when the impact F acts.
When an impact F such as falling rocks acts on a part of the buffer restraint layer 30, the hard cushioning material 32 enclosed in the restraint rod 31 is restrained by the restraint rod 31 and undergoes compaction deformation, and the entire impactor 35 is not fully damaged. It bends and deforms from the state shown by the dotted line. The impact F is attenuated by the consolidation deformation resistance of the hard cushioning material 32 and the bending resistance of the impactor 35.
Even if the impact F repeatedly acts, the restraining rod 31 prevents the hard cushioning material 32 from jumping out, and the sealed state of the hard cushioning material 32 is maintained.

<3> Dispersion Transmission Range of Impact in Protection Dyke Body A distributed transmission range of impact F in the protection dam body 10 will be described with reference to FIG.
The protective dam body 10 according to the present invention not only attenuates the impact F by the compaction deformation resistance of the hard cushioning material 32 and the deflection resistance of the impactor 35, but also a buffer constraint by combining a plurality of factors described below. The impact F acting on a part of the layer 30 can be dispersed in a wide range and transmitted to the dam body main body 20 to be efficiently attenuated.

<3.1> Dispersion and transmission action of impact by cured buffer restraint layer When impact F acts on a part of the buffer restraint layer 30 configured by connecting the plurality of impact bodies 35 via the connecting member 34, The impact F is transmitted in a chained manner not only to the impact body 35 to which the direct impact F has been applied, but also to the impact body 35 located around the impact body 35 through the connecting member 34 and the restraint rod 31.
When the compression deformation of the hard cushioning material 32 constrained by the horizontally long restraint rod 31 reaches the limit in each impactor 35, the hard cushioning material 32 group is locked, and the hardness of the impactor 35 is semi-rigid to a stone pillar. It changes to hard like this. The curing range of the buffer constraining layer 30 increases in proportion to the magnitude of the impact F.
Therefore, the impact F that has acted on a part of the buffer restraint layer 30 is transmitted over a wide range to the receiving surface 20 b of the levee body 20 through the horizontally hardened receiving body 35.
Since the buffer constraining layer 30 and the receiving surface 20b of the dam body main body 20 are in contact with each other, the transmission loss of the impact F is small.
Since the impact F transmitted to the levee body 20 can be effectively attenuated by the cooperation of the deformation resistance of the embankment layer 21 and the tensile strength of the embankment reinforcement 22, the protection performance of the protection dam body 10 compared to the conventional case. Becomes higher.

<3.2> Dispersion and Transmission Action of Impact by Increasing the Impact Area The impact surface 20b of the levee body 20 is not a planar shape, but an uneven three-dimensional shape corresponding to the uneven pressing surface 37 of the buffer restraint layer 30. Therefore, the ground contact area between the levee body main body 20 and the buffer restraint layer 30 is greatly increased as compared with the case where the receiving surface 20b is formed as a flat surface.
As the ground contact area (receiving area) between the dam body body 20 and the buffer restraint layer 30 increases, the dispersion transmission area of the impact F between the dam body body 20 and the buffer restraint layer 30 increases, so that the impact F Improves the damping performance.

<3.3> Dispersion and transmission action of impact by hardening of receiving surface The receiving surface 20b of the main body 20 is hardened to some extent by sufficiently rolling the embankment, but through the hardened buffer restraint layer 30, the main body When the impact F is transmitted to the 20 receiving surfaces 20b, the hardness of the surface layer of the receiving surface 20b is further increased and becomes hard like a stone.
It is because the earth and sand which comprise the receiving surface 20b mesh by the impact F being instantaneously added to the receiving surface 20b through the uneven | corrugated pressing surface 37. FIG.
The impact F is distributed and transmitted over a wide area of the dam body 20 through the hardened surface layer of the receiving surface 20b, and the interior of the dam body 20 through the surface layer of the receiving surface 20b hardened while maintaining the uneven shape. Since the transmission direction of the shock F in the radial direction spreads radially, the damping performance of the shock F is further improved.

<4> Load burden on the levee body When viewed from the dam body 20 side, the impact F is transmitted through one or more hardened bodies 35 that are hardened.
If the transmission area of the impact F in the levee body 20 is increased, the load burden per unit area as the protective dam body 10 is reduced, which is advantageous in designing the protective dam body 10 to be small and light.
If the protective dam body 10 can be reduced in size and weight, the burden on the supporting ground can be reduced, so there is no need for ground improvement.

<5> About the tensile force acting on the restraint rod The tensile force acting on the restraint rod 31 at the time of impact will be examined.
The hard cushioning material 32 enclosed in the restraint rod 31 causes an interlocking phenomenon when an external force is applied, thereby preventing free deformation.
The interlocking phenomenon is caused by the internal friction of the hard cushioning material 32 and is not greatly influenced by the strength of the restraint rod 31. Even by restraining with the restraint rod 31 having a small strength, the hard cushioning material 32 causes a locking phenomenon.
In this way, when the hard cushioning material 32 causes a locking phenomenon, an excessive tensile force does not act on the restraint rod 31, so that the restraint rod 31 is not damaged by the tensile force at the time of impact.

[Other embodiments]
Other embodiments will be described below. In the description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 shows a configuration in which a reinforcing connecting member 36 such as a steel rod is arranged at the joint portion between adjacent impact bodies 35 to increase the connection strength.
Since the coil-shaped connecting material 34 is wound between the adjacent receiving bodies 35, the reinforcing connecting material 36 is inserted and installed in the inner space of the connecting material 34.
The installation range of the reinforcing connecting member 36 is installed at the full length of each side of the restraint rod 31 or a part thereof.
In addition, the code | symbol 31f in a figure is the frame material which comprises the restraint rod 31. FIG.
Since the reinforcing connecting member 36 cooperates with the connecting member 34 to enhance the integrity between the impact bodies 35, the impact transmission is improved as compared with the case where the connecting member 34 is used alone.

In the previous embodiment, the case where the mountain-side receiving surface 20b of the levee body main body 20 and the buffer constraining layer 30 are formed vertically has been described, but a slope may be provided as shown in FIGS.
FIG. 7 shows the protective dam body 10 in which the front surface of the buffer restraint layer 30 is formed flat using the restraint rod 31 having a rhombus cross section, and FIG. 8 shows the buffer restraint layer 30 using the restraint rod 31 having a rectangular section. The protection bank body 10 which formed the front surface in step shape is shown.
As in this example, the stability of the protective dam body 10 is increased by forming the buffer constraining layer 30 in a slanted manner with a gradient.

  In the above description, the plurality of impact bodies 35 are arranged in a vertical row. However, when the expected impact F is enormous, the plurality of impact bodies 35 may be arranged in multiple rows.

DESCRIPTION OF SYMBOLS 10 ... Protective dam body 20 ... dam body main body 21 ... embankment layer 22 ... embankment reinforcement 23 ... wall material 24 ... Fixing pin 25 ... Suction prevention sheet 30 ... Buffer restraint layer 31 ... Restraint rod 32 ... Hard shock absorber 35 ... Impactor 36 ... ..Reinforcement connecting material 37 ... uneven pressing surface

Claims (6)

A protective levee body comprising a levee body having a receiving surface and a semi-hard buffer restraint layer covering the receiving surface,
The levee body is composed of a reinforced embankment body,
The buffer restraint layer is composed of a plurality of impact bodies that contain a hard cushioning material in a horizontally long restraint so as to be restrained,
Connecting the plurality of impact bodies so that a load can be transmitted between adjacent impact bodies;
The buffer restraint layer has an uneven pressing surface in which a part of the hard cushioning material protrudes from the back surface toward the receiving surface of the levee body body on the back surface ,
Between the uneven pressing surface of the buffer restraint layer and the surface layer of the receiving surface of the dam body main body deformed into an uneven shape corresponding to the uneven pressing surface, an anti-suction sheet is interposed,
A protective levee body that disperses and transmits shock acting on the buffer restraint layer to the dam body main body through a buffer restraint layer whose hardness changes from semi-rigid to hard when it receives an impact. According to claim 1, so that the uneven pressing surface to receive撃時to pressure deform the受撃surface of the dam body, characterized in that the size of the back of the opening and the hard cushioning material of the restraining cage is related Protective levee body.   3. The protective levee body according to claim 2, wherein an opening on a front surface of the restraint rod is smaller than an opening on a rear surface of the restraint rod. In Claim 2 or 3, the said embankment embankment body contacted the uneven | corrugated pressing surface of a receiving body through the suction prevention sheet | seat, the some embankment layer built hierarchically, and the embankment laid between each embankment layer A protective embankment comprising a reinforcing material.   The protective bank body according to any one of claims 1 to 3, wherein a cross-sectional shape of the impactor is a square.   The coil-shaped connection which connects between these impact bodies in any one of Claims 1 thru | or 5. Adjacent impacts using both a tie and a bar-shaped reinforcing connecting material inserted into the coil-shaped connecting material A protective embankment characterized by connecting between bodies.

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