JP7368279B2 - Rubble stone structures and their construction methods - Google Patents

Description

The present invention relates to, for example, a rubble structure formed by layering rubble stones, which is provided along the extending direction of a rubble revetment or a rubble embankment, and a method for constructing the same.

The structure of the seawall that forms the outer shell of a reclaimed land (artificial island) constructed in a sea or water body can be classified into heavy-weight types such as rubble type, cell type, sheet pile type, and caisson type. It will be constructed in combination. In addition, there are various types of breakwaters constructed in harbors, fishing ports, etc., such as rubble-type dikes represented by sloped rubble-type dikes, caisson-type vertical dikes, and hybrid dikes with caisson erected on top of rubble mounds. The structure is selected depending on the conditions.

Therefore, as shown in FIG. 1, a rubble-type seawall (hereinafter referred to as a rubble-stone seawall) 100 is provided with a sand layer 101 formed by laying sand on the bottom surface of a predetermined water area. A sand layer 102 is provided on top of which sand is piled up. Moreover, a rubble structure 103 having a substantially trapezoidal cross section, which is formed by stacking a large number of rubble stones (for example, weighing 10 to 200 kg/piece) on the sand bed layer 102, is provided in two stages along the vertical direction, and the upper side A covering stone portion 104 is provided on the offshore slope of the rubble structure 103 in which a large number of covering stones (for example, weighing 400 to 600 kg/piece) are arranged so as to cover the slope. Further, a wave-dissipating block section 105 is provided on the off-shore slope of the covering stone section 104, in which a large number of wave-dissipating blocks are arranged so as to cover the section 104, and a wave-dissipating block section 105 is provided on the shore side of the lower rubble structure 103. A sand embankment layer 102 is provided from the slope toward the shore, and an upper block (including pouring of upper concrete) 106 is placed on the upper end surface of the upper rubble structure 103 to construct the rubble revetment 100. Then, earth and sand are poured into the inside of the rubble stone revetment 100 and layered to create land.

Further, as shown in FIG. 2, the rubble embankment 200 is provided with a rubble structure 103 having a substantially trapezoidal cross section, which is formed by stacking a large number of rubble stones on the bottom surface of a predetermined water area. A covering stone portion 104 is provided in which a large number of covering stones are arranged to cover the range from the offshore slope and shore side slope to the bottom surface. Moreover, a wave-dissipating block section 105 is provided on each covering stone section 104, in which a large number of wave-dissipating blocks are arranged so as to cover the section 104, and concrete is placed on the upper end surface of the rubble structure 103. An upper concrete pouring portion 107 is provided, and the rubble embankment 200 is constructed.

However, in the completed rubble stone revetment 100 or rubble stone embankment 200 as described above, its stability against the required design waves is ensured, but the If high waves attack during construction of the rubble structure 103 (the upper rubble structure 103 in the rubble revetment 100 in FIG. 1) before the block (wave-dissipating block part 105) is installed, the weight of the rubble will be reduced. Because they are small, they are scattered by the wave force, causing damage such as the cross-sectional shape of the rubble structure 103 being deformed due to scattering and washing away of the rubble stones.

In order to prevent such damage and ensure the stability of the rubble structure 103 during the construction of the rubble stone revetment 100 and the rubble stone embankment 200, in the past, it has been necessary to Measures should be taken to temporarily cover the surface of the rubble structure 103 with a stone heavier than the rubble, such as covering stone, or a mesh bag filled with rubble, or with a net made of wire or chain. Countermeasures such as covering the surface of the rubble structure 103 have been taken, but the effects of these measures are limited and no fundamental solution has been reached.

Therefore, in Patent Document 1, a required amount of rubble is filled in a rectangular steel cage to form a rubble stone cage body for a method, and the rubble stone cage body is sequentially placed on the seabed raw ground on the required slope surface. A method for constructing a rubble embankment for sea protection is disclosed, in which rubble materials are sequentially introduced and filled behind the stacked rubble cages while stacking them at a slope to form a slope embankment body.

Japanese Patent Application Publication No. 11-247154

However, even in the method for constructing a rubble embankment for seawalls described in Patent Document 1, if high waves attack during construction, the rubble materials stacked behind the rubble stone cage will scatter and exceed the rubble stone cage. The problem described above cannot be solved.

The present invention has been made in view of these points, and provides a rubble stone structure and its structure that can suppress the deformation of the cross-sectional shape along the offshore direction while ensuring stability even when high waves attack. The purpose is to provide a construction method.

As a means for solving the above problems, the present invention provides a rubble structure according to claim 1, which is constructed by laminating a large number of rubble stones provided along the extending direction of a rubble revetment or a rubble embankment. It is a rubble stone structure, and the rubble stone structure has an overall approximately trapezoidal external shape in its completed cross-sectional structure along the shore-offshore direction, and has a pre-calculated resistance from waves to the rubble stone structure. A foundation section that extends along the shore-offshore direction by stacking a large number of rubble stones at a position deeper than the water depth threshold where the influence of A core part formed by laminating a large number of layers, a net body covering the core part from the top end along the offshore slope and the shore side slope, and a large number of rubble stones around the core part including the net body. and a pair of peripheral parts formed by laminating layers, and the net body is characterized in that it is configured to allow the passage of water while restricting the passage of rubble.
In the invention of claim 1, even if high waves attack the rubble structure during the construction of a rubble revetment or rubble embankment, the core part is held by the net, so that the lamination in the core part due to the waves will not occur. Furthermore, it is possible to suppress the scattering and washing away of a large number of rubble stones, and furthermore, it is possible to suppress the deformation of the cross-sectional shape of the rubble structure along the shore-offshore direction.
In addition, the foundation is made of a large number of stacked rubble stones and extends in the offshore direction at a position deeper than the pre-calculated water depth threshold at which the impact of waves on the rubble structure is reduced. The mesh can hold areas in the core where a large number of stacked rubble stones are expected to be scattered or washed away by waves. As a result, it is possible to suppress scattering and washing away of a large number of laminated rubble stones caused by waves in the core portion.

In the invention of the rubble structure described in claim 2 , in the invention described in claim 1 , the threshold value of the water depth is a predetermined value within a range of 0.8 to 1.5 relative to the significant wave height (m) of the incident wave. It is characterized by being multiplied by a value.
In the invention of claim 2 , it is possible to calculate in advance the threshold value of the water depth at which the rubble structure is affected by waves, and it is possible to easily specify the range of the core portion to be covered with the net.

The invention of the rubble structure set forth in claim 3 is the invention set forth in claim 1 or 2 , in which a large number of rubble stones are provided in a net-like cage for restraining both ends of the net body in the shore-offshore direction in that position. It is characterized by having a gabion filled with.
According to the third aspect of the present invention, it is possible to reliably suppress the displacement of the net, and in turn, it is possible to reliably hold the core portion by the net.

The invention relating to a method for constructing a rubble structure according to claim 4 is a method for constructing a rubble structure formed by stacking a large number of rubble stones provided along the extending direction of a rubble embankment or a rubble embankment, In the completed cross-sectional structure along the shore-offshore direction, a large number of rubble stones are stacked at a position deeper than a pre-calculated water depth threshold at which the influence of waves on the rubble structure is reduced, and extend along the shore-offshore direction. a foundation construction step for constructing a foundation; a core construction step for constructing a core section formed by laminating a large number of rubble stones in a range along the shore-offshore direction on the foundation; and a top of the core section. A net covering step covers a net that allows the passage of water but restricts the passage of rubble along the shore side and offshore side from the end, and rubble is placed around the core portion including the net. The present invention is characterized in that it includes a completion construction step of constructing a peripheral portion formed by laminating a large number of layers, and completing a completed cross-sectional structure along the shore-offshore direction.
In the invention of claim 4 , in particular, the net covering step is performed after the core part construction step, and the core part can be held by the net from this point on, so that even if high waves attack during the construction of the rubble structure, It is possible to suppress the scattering and washing away of a large number of rubble stones by waves in the core part, and it is possible to suppress the deformation of the cross-sectional shape along the shore-offshore direction during construction of the rubble structure.

The invention relating to the method for constructing a rubble structure according to claim 5 is the invention according to claim 4 , in which, between the net covering step and the completed construction step, both ends of the net in the shore-offshore direction are provided. The present invention is characterized by comprising a net restraining step for restraining each of the stones in its position by a gabion in which a large number of rubble stones are packed inside a net-like cage.
According to the fifth aspect of the present invention, both ends of the net in the shore-offshore direction can be restrained at the positions by the net restraining step, so that the core can be reliably held by the net.

The invention relating to the construction method of a rubble structure set forth in claim 6 is the invention set forth in claim 5 , in which, in the net restraining step, the upper surface of the gabion is located at a position that substantially coincides with the water depth threshold, or The water depth threshold is the significant wave height (m) of the incident wave multiplied by a predetermined value within the range of 0.8 to 1.5. be.
In the invention of claim 6 , it is possible to calculate in advance the threshold value of the water depth at which the rubble structure is affected by waves, and the range to be covered with the net can be easily specified.

In the rubble structure according to the present invention, even if high waves attack the rubble structure during the construction of a rubble revetment or a rubble embankment, the stability of the rubble structure is ensured while suppressing the scattering and washing away of the rubble. This makes it possible to suppress deformation of the cross-sectional shape of the rubble structure along the shore-offshore direction.
Further, in the method for constructing a rubble structure according to the present invention, the stability of the rubble structure can be ensured during construction of the rubble structure, so that the workability of the rubble structure is improved.

FIG. 1 is a schematic cross-sectional view along the shore-offshore direction of a rubble seawall in which a rubble structure according to an embodiment of the present invention is employed. FIG. 2 is a schematic cross-sectional view along the shore-offshore direction of a rubble embankment in which a rubble structure according to an embodiment of the present invention is employed. FIG. 3 is a cross-sectional view of the rubble structure according to the embodiment of the present invention, taken along the shore-offshore direction. FIG. 4 is a perspective view of a net body employed in a rubble structure according to an embodiment of the present invention. FIG. 5 is a perspective view of a gabion employed in the rubble structure according to the embodiment of the present invention. FIG. 6 is a cross-sectional view of the rubble structure taken along the shore-offshore direction, showing step-by-step a construction method for building the rubble structure according to the embodiment of the present invention. Continuing from FIG. 6, FIG. 7 is a cross-sectional view of the rubble structure along the shore-offshore direction, showing step-by-step the construction method for building the rubble structure according to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail based on FIGS. 1 to 7.
The rubble structure 1 according to the embodiment of the present invention is particularly applied to a rubble embankment 100 or a rubble embankment 200, as shown in FIGS. 1 and 2. In this embodiment, a rubble structure 1 adopted as a rubble revetment 100 will be described. The rubble structure 1 is constructed along the extending direction of the rubble revetment 100 with a substantially trapezoidal cross-section in the shore-offshore direction (see FIG. 3) by throwing a large number of rubble into a predetermined water area and stacking them. The rubble structure 1 is constructed by stacking a large number of rubble stones each having a grain size of about 200 to 600 mm and weighing about 10 to 200 kg. Note that the shore-offshore direction referred to here is a direction perpendicular to the direction in which the rubble seawall 100 is extended, and is the same direction as the direction in which waves rush toward the rubble seawall 100 (wave direction).

As shown in FIG. 3, the rubble structure 1 according to the embodiment of the present invention has a complete cross-sectional structure 10 along the shore-offshore direction, and its outer shape as a whole has a substantially trapezoidal shape. Specifically, the rubble structure 1 according to the present embodiment is a completed cross-sectional structure 10 along the shore-offshore direction, and has a water depth threshold calculated in advance at which the influence of waves on the rubble structure 1 is reduced. A foundation part 3 that extends along the shore-offshore direction by laminating a large number of rubble stones at a position deeper than H, and a large number of rubble stones are laminated in a range on the foundation part 3 approximately at the center along the shore-offshore direction. A core part 4, a net body 5 that covers the core part 4 from the top end along the offshore slope and the shore side slope, and a large number of rubble stones are stacked around the core part 4 including the net body 5. A pair of peripheral portions 6, 6 formed of. Note that the thick lines shown in FIGS. 3 and 7 indicate the mesh body 5.

The foundation part 3 has a substantially trapezoidal shape and is positioned at the bottom end of the completed cross-sectional structure 10 along the shore-offshore direction. The shore side slope and the offshore side slope of the foundation part 3 substantially correspond to the shore side slope and the offshore side slope of the completed cross-sectional structure 10, respectively. The foundation 3 is placed at a position deeper than a water depth threshold H at which the rubble structure 1 is less affected by waves. In short, the top of the foundation 3 is placed at a position deeper than the water depth threshold H, in other words, the water depth H1 at the top of the foundation 3 is greater than the water depth threshold H. This water depth threshold H is calculated in advance and is within the range of 0.8 to 1.5, preferably within the range of 1.0 to 1.5, based on the significant wave height (m) of the incident wave. is multiplied by a predetermined value. In this embodiment, the water depth threshold H is calculated by multiplying the significant wave height (m) of the incident wave by 1.2.

As shown in FIG. 3, the core part 4 is built on the foundation part 3 in a substantially central range along the shore-offshore direction. The core portion 4 has a substantially trapezoidal shape. The top end of the core portion 4 substantially coincides with the top end of the completed cross-sectional structure 10. Referring also to FIG. 6, the top width W1 of the core portion 4 is narrower than the top width W of the completed cross-sectional structure 10. The slopes of the shore-side slope and the offshore slope of the core portion 4 substantially match the slopes of the shore-side slope and the offshore slope of the completed cross-sectional structure 10, respectively. A net body 5 is arranged to cover the core part 4 from the top thereof along the shore-side slope and the offshore slope.

Referring also to FIG. 4, the net body 5 (net) is configured to restrict the passage of rubble while allowing the passage of water. The net body 5 has flexibility. The large number of openings 5a provided in the net body 5 are set to a size such that rubble cannot pass through them. For example, when the rubble used in the rubble structure 1 has a particle size of 200 to 600 mm, each opening 5a of the net body 5 is set to a size that does not allow the rubble with a particle size of 200 mm to pass through. The mesh body 5 is made of metal, chemical fiber, synthetic resin, etc., and the material is not limited as long as it has a desired strength.

Both end portions 5b, 5b of the net body 5 in the shore-offshore direction are arranged at a position deeper than a water depth threshold H at which the rubble structure 1 is less affected by waves. Both end portions 5b, 5b of the net body 5 in the shore-offshore direction are arranged on the tops of the shore-side end and the offshore-side end of the foundation portion 3, respectively. Both end portions 5b, 5b of the net body 5 in the shore-offshore direction are restrained by gabions 12 on the tops of the shore-side end and the offshore-side end of the foundation portion 3, respectively. Referring to FIG. 5, gabion 12 is a cage in which a large number of rubble stones are packed. The basket has a net shape and is made of metal, chemical fiber, synthetic resin, etc., and the material is not limited as long as it has a desired strength.

A pair of peripheral parts 6, 6 are constructed on the foundation part 3 and around the core part 4 including the net body 5, that is, along the shore-side slope and the offshore-side slope of the core part 4. The peripheral portion 6 has a substantially parallelogram shape. In the shore-side peripheral portion 6, the shore-side slope substantially coincides with the bank-side slope of the completed cross-sectional structure 10. On the other hand, in the offshore peripheral portion 6, the offshore inclined surface substantially coincides with the offshore slope of the completed cross-sectional structure 10. Further, the top ends of the pair of peripheral parts 6, 6 substantially coincide with the top ends of the core part 4, that is, the top ends of the completed cross-sectional structure 10, respectively. A completed cross-sectional structure 10 along the shore-offshore direction is established by these foundation portion 3, core portion 4, net body 5, and pair of peripheral portions 6, 6. In addition, in the completed cross-sectional structure 10 of the rubble stone structure 1 along the shore-offshore direction, the net body 5 is exposed at a portion of the top of the rubble stone structure 1 at a substantially central portion in the shore-offshore direction.

Next, a method for constructing a rubble structure 1 according to an embodiment of the present invention will be described based on FIGS. 6 and 7. In FIG. 6(a), the external shape (approximately trapezoidal shape) of the completed cross-sectional structure 10 of the rubble structure 1 along the shore-offshore direction is shown by a two-dot chain line. First, a foundation construction step is performed in the completed cross-sectional structure 10 along the shore-offshore direction. In the foundation construction step, as shown in FIG. 6(b), a large number of rubble stones are placed at the bottom of the predetermined water area so as to form the bottom end of the completed cross-sectional structure 10 of the rubble structure 1 along the offshore direction. Then, the foundation part 3 extending in the shore-offshore direction is constructed. The foundation 3 is constructed at a position deeper than a water depth threshold H at which the influence of waves on the rubble structure 1 is reduced. The base portion 3 has a substantially trapezoidal shape as described above. Further, the shore-side slope and offshore-side slope of the foundation portion 3 are made to substantially match the shore-side slope and offshore-side slope of the completed cross-sectional structure 10, respectively. In this embodiment, the water depth H1 at the top of the foundation 3 is the water depth equal to the water depth threshold H plus the height of the gabion 12 (see FIG. 7(b)).

Next, a core part building step is performed. In the core part construction step, as shown in FIG. 6(c), a core part 4 is constructed by laminating a large number of rubble stones in a range approximately in the center on the foundation part 3 along the offshore direction. . At this time, the core portion 4 has a substantially trapezoidal shape, as described above, and its top end substantially coincides with the top end of the completed cross-sectional structure 10. Further, the slopes of the shore-side slope and the offshore slope of the core portion 4 are made to substantially match the slopes of the shore-side slope and the offshore slope of the completed cross-sectional structure 10, respectively.

Next, a mesh covering step is performed. In the net covering step, as shown in FIG. 7(d), the net 5 is covered from the top of the core portion 4 along the shore-side slope and the offshore slope. Both end portions 5b, 5b of the net body 5 in the shore-offshore direction are arranged on the tops of the shore-side end and the offshore-side end of the foundation portion 3, respectively. As described above, the net body 5 is configured to allow the passage of water while restricting the passage of rubble.

Next, a net body restraining step is performed. In the net body restraining step, as shown in FIG. 7(e), gabions 12 each filled with a large number of rubble stones are placed on both ends 5b, 5b of the net body 5 in the shore-offshore direction, and the net body 5 is restrained. do. At this time, in this embodiment, the upper surface of each gabion 12 is arranged at a position that substantially coincides with the water depth threshold H. Note that the top surface of each gabion 12 may be placed at a position deeper than the water depth threshold H.

Next, a final construction step is performed. In the completion construction step, as shown in FIG. 7(f), a pair of peripheral parts 6, 6 made by laminating a large number of rubble stones are constructed around the core part 4 including the net body 5, and the peripheral parts 6, 6 are constructed in the direction off shore. It is completed as a completed cross-sectional structure 10 along the line. That is, in the completion construction step, a pair of constructions are carried out on the foundation part 3 around the core part 4 including the net body 5, that is, along the shore side slope and the offshore slope of the core part 4 including the net body 5. The peripheral parts 6 and 6 are constructed respectively. At this time, the shore-side inclined surface of the shore-side peripheral part 6 is made to substantially match the shore-side slope of the completed cross-sectional structure 10, and the offshore-side slope of the offshore peripheral part 6 is made to coincide with the shore-side slope of the completed cross-sectional structure 10. Approximately match the surface. Further, the top ends of the pair of peripheral parts 6, 6 are made to substantially match the top ends of the core part 4, that is, the top ends of the completed cross-sectional structure 10, respectively. Thereby, the rubble structure 1 according to the embodiment of the present invention is completed.

As explained above, in the rubble structure 1 according to the embodiment of the present invention, in the completed cross-sectional structure 10 along the shore-offshore direction, a large number of rubble stones provided on the inside in the shore-offshore direction are stacked and The core part 4 constructed along the direction is provided with a net body 5 arranged to cover the core part 4 from the top end along the shore side slope and the offshore side slope, and the net body 5 It is configured to allow the passage of rubble stones but restrict the passage of rubble.
As a result, even if high waves attack the rubble stone structure 1 during the construction of the rubble stone revetment 100, the core part 4 is held by the net body 5, so that many of the core parts 4 are laminated due to waves. The scattering and washing away of rubble stones can be suppressed. As a result, the cross-sectional shape of the rubble structure 1 along the shore-offshore direction is deformed before the covering stone (covering stone part 104 in Fig. 1) and wave-dissipating block (wave-dissipating block part 105 in Fig. 1) are installed. can be suppressed. In short, even if high waves attack the rubble stone structure 1 during construction of the rubble stone revetment 100, deformation of the cross-sectional shape along the offshore direction can be suppressed while ensuring stability.

Further, in the rubble structure 1 according to the embodiment of the present invention, both ends 5b, 5b of the net body 5 in the shore-offshore direction are set to a pre-calculated water depth threshold at which the influence of waves on the rubble structure 1 is reduced. It is placed at a deeper position than H. Thereby, the net body 5 can reliably hold the portion of the core portion 4 where a large number of laminated rubble stones are expected to be scattered or washed away by waves.

Furthermore, in the rubble structure 1 according to the embodiment of the present invention, the water depth threshold H is the significant wave height (m) of the incident wave multiplied by a predetermined value within the range of 0.8 to 1.5. . Thereby, the range in the core portion 4 to be covered with the net body 5 can be easily specified.

Furthermore, in the rubble structure 1 according to the embodiment of the present invention, a gabion 12 in which a large number of rubble stones are packed in a net-like cage is used to restrain both ends 5b, 5b of the net body 5 in the shore-offshore direction in their positions. It is equipped with Thereby, the positional shift of the net body 5 can be suppressed reliably. As a result, the core portion 4 can be reliably held by the mesh body 5.

Furthermore, in the method for constructing a rubble structure according to the embodiment of the present invention, in particular, a net covering step is performed after the core part building step, and the core part 4 can be held by the net 5 thereafter. As a result, even if high waves attack during the construction of the rubble structure 1, it is possible to suppress scattering and washing away of a large number of rubble stones in the core portion 4 due to the waves. Thereby, during the construction of the rubble stone structure 1, deformation of the cross-sectional shape along the shore-offshore direction can be suppressed, and the workability of the rubble stone structure is improved.

In the rubble structure 1 according to the present embodiment, both end portions 5b, 5b of the net body 5 in the shore-offshore direction are placed on top of the shore-side end and the offshore-side end of the foundation portion 3 by respective gabions 12. Although this is the best form, both ends 5b of the net body 5 in the shore-offshore direction may be restrained in that position by stacking a large number of rubble on top of each gabion 12 instead of each gabion 12. Alternatively, the shore side end 5b of the net 5 can be restrained in that position by stacking a large number of rubble stones thereon, and the gabion 12 can be placed on the offshore side end 5b of the net 5. You can also restrict it to that position. This is because both ends 5b, 5b of the net body 5 in the shore-offshore direction are placed at a position deeper than the water depth threshold H at which the influence of waves on the rubble structure 1 is reduced. Even if the portions 5b, 5b are restrained by a large number of rubble stones, these rubble stones are hardly scattered or washed away, and it is possible to sufficiently restrain both end portions 5b, 5b of the net body 5 in the offshore direction. This is because it is taken into account.

Further, in the rubble structure 1 according to the present embodiment, the gabions 12 are employed to restrain the both ends 5b of the net body 5 in the shore-offshore direction, but what is called a filter unit may also be employed. Specifically, the filter unit is a flexible net-like bag filled with a large number of rubble stones, and has substantially the same structure as the gabion 12 and can perform the same function. Furthermore, in the rubble stone structure 1 according to the present embodiment, the core part 4 is built on the foundation part 3 in a range approximately in the center along the shore-offshore direction, but it is biased toward the shore side or offshore side. It may be built in any location.

Furthermore, in the rubble stone structure 1 according to the present embodiment, the core portion 4 is configured to be covered with the net body 5 from the top end along the shore side slope and the offshore side slope. The core section 4 is divided into a plurality of layers in the vertical direction, for example, a first core layer, a second core layer, and a third core layer. The net 5 is interposed between the second layer of the core portion and the third layer of the core portion, and then, as in the present embodiment, the entire core portion 4 is covered with the net 5. It may be configured so that it is covered by the step 5.

1 Rubble stone structure, 3 Foundation part, 4 Core part, 5 Net body, 5b End part, 6 Peripheral part, 10 Completed cross-sectional structure, 12 Gabion, 100 Rubble stone revetment, 200 Rubble embankment

Claims (6)

A rubble structure constructed by stacking a large number of rubble stones and provided along the extension direction of a rubble revetment or rubble embankment,
The rubble stone structure has an overall approximately trapezoidal external shape in its completed cross-sectional structure along the offshore direction,
a foundation portion that extends along the shore-offshore direction by stacking a large number of rubble stones at a position deeper than a pre-calculated water depth threshold at which the influence of waves on the rubble structure is reduced;
A core part formed by stacking a large number of rubble stones in a generally central area on the foundation part along the shore-offshore direction;
A net body that covers the core portion from its top end along an offshore slope and a shore slope;
a pair of peripheral parts formed by laminating a large number of rubble around the core part including the net body;
Equipped with
A rubble structure characterized in that the net body is configured to restrict the passage of rubble while allowing the passage of water. The rubble structure according to claim 1 , wherein the water depth threshold is a significant wave height (m) of an incident wave multiplied by a predetermined value within a range of 0.8 to 1.5. 3. The rubble structure according to claim 1 , further comprising a gabion in which a large number of rubble stones are packed in a net-like cage for restraining both ends of the net body in the shore-offshore direction in that position. A method for constructing a rubble structure formed by stacking a large number of rubble stones, which is provided along the extension direction of a rubble revetment or rubble embankment,
In the completed cross-sectional structure along the shore-offshore direction,
a foundation construction step of building a foundation extending along the offshore direction by stacking a large number of rubble stones at a position deeper than a pre-calculated water depth threshold at which the influence of waves on the rubble structure is reduced; ,
a core part construction step of constructing a core part formed by stacking a large number of rubble stones in a range along the shore-offshore direction on the foundation part;
a net covering step for covering the core portion from the top end along the shore side surface and the offshore side surface with a net that restricts the passage of rubble while allowing the passage of water;
a completion construction step of constructing a peripheral part made by stacking a large number of rubble stones around the core part including the net body to complete a completed cross-sectional structure along the shore-offshore direction;
A method for constructing a rubble structure, characterized by comprising: Between the mesh covering step and the finished construction step,
The rubble structure according to claim 4 , further comprising a net restraining step for restraining both ends of the net in the shore-offshore direction by a gabion in which a large number of rubble is packed in a net-like cage. construction method. In the net restraining step, the upper surface of the gabion is placed at a position that substantially coincides with the water depth threshold, or at a position deeper than that, and the water depth threshold is set to 0. 6. The method for constructing a rubble structure according to claim 5 , wherein the value is multiplied by a predetermined value within a range of 8 to 1.5.

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