JP6018804B2 - Cell body water-blocking structure - Google Patents

Description

  The present invention relates to a water shielding structure for a cell main body in a cell type water-impervious revetment in which cell main bodies are connected by an arc portion.

  Conventionally, in order to construct a water-impervious revetment such as a waste sea surface disposal site, a plurality of caissons and cells having a water-impervious structure are connected to each other and installed on the seabed. In particular, impermeable revetments using steel plate cells are towed and transported steel cell shells and arcs made at factories and yards to the construction site of the revetment, compared to impermeable revetments using caisson, Since it is possible to construct a water-impervious revetment easily by assembling it into a steel plate cell locally, there is an advantage that the construction cost is low and the construction can be completed in a short period of time.

  For example, as described in Patent Document 1, a conventional cell-type impermeable revetment places a steel plate cell on the seabed ground, penetrates the lower end, and fills the cell shell with a filling material. At the same time, the outside sea side and the revetment inside of the steel plate cells are connected by arcs rooted in the seabed ground, respectively, and a construction method in which a filling material is filled between these arcs is constructed.

  In addition, when the seabed ground is hard and it is difficult to place a steel plate cell or an arc, for example, as described in Patent Document 2, a layer of foundation waste stone is placed in a recess formed by excavating the seabed ground. The steel plate cell is placed on the cell shell, and the cell shell is filled with the filling material, and the outside sea side and the inside of the steel plate cells are connected by two arcs to fill the arc part. After filling the material, it is constructed by a method of backfilling the periphery of the steel plate cell and the lower end of the arc part with a backfill material.

  FIG. 9 is a perspective partial view showing an example of a cross-sectional structure of a cell body in a conventional steel plate cell installed in a recess on such a submarine ground. As shown in FIG. A plurality of cylindrical cell bodies 22 and arc portions 23 that block between the cell bodies 22 are configured.

  Each cell main body 22 has a cell shell 22A made of a steel plate having an open bottom surface, and is placed on a foundation stone 25 in a recess 24A formed in the seabed ground 24. The cell shell 22A is filled with a filling material 26 such as earth and sand, and the upper end is closed by a concrete canopy 27.

Each arc portion 23 has a pair of steel plate arcs 23A that connect the cell shells 22A of the adjacent cell main bodies 22, and the lower ends of these arcs 23A are the basic waste stones 25 in the recesses 24A. It is placed on top.

  The seabed ground 24 in the vicinity of the recess 24A is an impermeable improved ground, and the gap between the outer peripheral surface in the vicinity of the lower end of the cell shell 22A or the arc 23A and the vertical side wall surface of the recess 24A is impermeable to water such as asphalt mastic. Blocked by the material 28, leakage of contaminated water from the revetment inside (waste sea surface disposal site side) to the open sea side is blocked.

  Although not shown in FIG. 9, a filling material similar to the filling material 26 is provided in the space defined by the adjacent cell shells 22 </ b> A and a pair of arcs 23 </ b> A connecting them. The upper end is closed by a concrete canopy 29 having the same height as the canopy 27.

Japanese Patent No. 4139871 Japanese Patent No. 4778460

  As described above, the thickness of the cell shell of the cell body used for the cell-type impermeable revetment is generally made extremely thin compared to its diameter. For example, even if the cell body has a diameter of about 14 m. The thickness of the steel plate used for the cell shell is only about 9 mm, and it is designed to withstand external forces such as seawater pressure acting from the outside by filling the inside of the cell shell with a filling material. .

  For this reason, in the splash zone on the outer periphery of the cell shell that is exposed to the sea surface and is constantly exposed to wave winds, rust and corrosion tend to proceed. For example, as shown in FIG. If the hole h is opened at the top of the wall due to rust or corrosion, the contaminated water from the waste sea surface disposal site inside the revetment flows into the inside of the cell shell 22A from the hole h, and is filled with poor water shielding. There is a possibility that the material 26 permeates and enters the foundation discard stone 25 from the lower end of the cell shell 22A having no bottom.

  The outer sea side and the revetment inner side of the lower part of the outer peripheral surface of the cell shell 22A are double water-blocked on both sides by the water-blocking material 28 filled in the concave portion 24A of the seabed ground 24. As described above, If contaminated water enters the inside of the cell shell 22A, if there is a gap between the cell shell 22A and the water shielding material 28 due to ground subsidence or the like on the side facing the open sea, There is a risk that the contaminated water from the sea surface disposal site will leak into the open sea.

  In order to avoid such a risk, a cell shell with a bottom may be used. However, if the cell shell is provided with a bottom, the manufacturing cost is increased and the bottom plate is made of a thin cylindrical cell shell. If the cell shell 22A is distorted by an external force, the stress concentrates on the welded portion, and there is a possibility that cracking or corrosion proceeds from this portion.

  On the other hand, as shown in FIG. 11, a water-impervious layer 30 using a water-impermeable material is provided between the filling materials 26 filled inside the cell shell 22 </ b> A, and the filling materials 26 at the upper side and the lower side are provided. If the water is shielded across the entire horizontal cross section inside the cell shell 22A, the contaminated water is blocked by the water shielding layer 30 even when the contaminated water enters the cell shell 22A as shown in FIG. Since it does not penetrate below, it is considered that the risk of leakage into the open sea can be avoided.

  By the way, when a large earth pressure acts on the outer peripheral surface of the cell shell 22A on the inner side of the revetment due to a difference between the water level on the outer sea side and the water level on the inner side of the revetment due to tides or the like, The pressure acting on the outer peripheral surface of the cell shell 22A becomes unbalanced on the outer sea side and the inner side of the revetment. As a result, the cell body 22 has a vertical direction and a horizontal direction perpendicular to the revetment normal as shown in FIG. Then, the shear load F acts.

  As shown in FIG. 9, when only the filling material 26 is densely filled inside the cell shell 22A, the shear load F is mainly subjected to deformation resistance due to interparticle friction of the filling material 26. Is supported by.

However, as shown in FIG. 11, when a low-rigidity water shielding material such as asphalt mastic is used for the water shielding layer 30 formed between the filling materials 26, the shear load F acts for a long time. Further, creep deformation occurs in the water shielding layer 30, and in this portion, the force for carrying the shear load F is reduced, and there is a possibility that local deformation or damage such as cracks may occur in the cell shell 22A .

  On the other hand, when a highly rigid water shielding material such as underwater concrete is used for the water shielding layer 30, a reduction in drag can be avoided by the creep deformation as described above, but such a highly rigid water shielding material is Although it is generally difficult to deform, it is weak against a rapidly changing force or impact force, and when an external force that changes in a short period such as an earthquake acts on the cell shell 22A, the inside of the water shielding layer 30 is locally excessive. As a result, there is a risk that the water shielding capability may be impaired due to the occurrence of cracks or the like in the water shielding layer 30 due to the stress.

  Therefore, the present invention eliminates the problems in the prior art as described above, and can form a water shielding layer inside the cell shell without reducing the strength of the cell body. It is an object of the present invention to provide a cell body water-blocking structure that can avoid the risk of leakage of contaminated water from the revetment inside to the open sea as much as possible even when water leaks.

  For the above purpose, the first of the present invention is a cell body water-blocking structure used for a cell-type impermeable revetment in which cell bodies are connected to each other by an arc portion. A composite impermeable layer, in which the impermeable layers are adjacent to each other at a perpendicular boundary perpendicular to the revetment normal, and are alternately arranged in the direction of the revetment normal, is perpendicular to the inside of the cell shell over the entire horizontal section. It is characterized by being formed with a predetermined width in the direction.

Moreover, the 2nd thing of this invention is the water-impervious structure of the cell main body used for the cell-type water-impervious revetment which connects the cell main bodies with an arc part, Comprising: In a water-impervious layer, it is orthogonal to a revetment normal line A composite water-impervious layer formed by embedding a shear load acting in the horizontal direction and a high-rigidity member carrying the shear load acting in the vertical direction is set in the vertical direction over the entire horizontal section inside the cell shell. A plurality of the high-rigidity members are provided, the longitudinal direction of which is a horizontal direction and coincides with a direction orthogonal to the revetment normal direction, and the revetment normal direction It is characterized by being arranged at equal intervals .

  According to the first aspect of the present invention, the vertical boundary surface perpendicular to the revetment normal is formed by the composite water-impervious layer formed with a predetermined width in the vertical direction over the entire horizontal cross section inside the cell shell. The shear load acting on the composite impermeable layer is mainly composed of a high-rigidity impermeable layer and a low-rigidity impermeable layer that are alternately arranged in the revetment normal direction. Since it resists with a high-rigidity impermeable layer, creep deformation of the low-rigidity impermeable layer can be prevented.

  In addition, when an earthquake occurs, the low-rigidity impermeable layer absorbs the vibration of the cell shell, so that excessive stress can be prevented from acting in the high-rigidity impermeable layer. The layer can be protected from damage such as cracks.

  As a result, by forming a composite water-impervious layer in the filling material, the composite water-impervious layer provides water shielding between the upper part and the lower part inside the cell shell without reducing the strength of the cell body. Therefore, even when water leaks in the cell shell due to rust or corrosion, the risk of leakage of contaminated water to the outside sea can be avoided as much as possible.

  According to the invention described in claim 2, a composite impermeable layer formed with a predetermined width in the vertical direction is formed on the inner side of the cell shell over the entire horizontal cross section thereof. Since the acting shear load is mainly shared by the high-rigidity member, the water-impervious layer in which the high-rigidity member is embedded exclusively performs the water shielding inside the cell shell. In addition, it is possible to block the water between the upper part and the lower part inside the cell shell with a composite water barrier layer without reducing the strength of the cell body, and the risk of leakage of contaminated water to the outside sea is reduced. It can be avoided as much as possible.

It is a horizontal sectional view showing a part of steel plate cell in a 1st embodiment of the present invention. It is sectional drawing which shows the AA cross section of FIG. It is sectional drawing which shows the BB cross section of FIG. It is sectional drawing of the cell main-body part which shows the modification of the 1st Embodiment of this invention. It is sectional drawing of the cell main-body part which shows another modification of the 1st Embodiment of this invention. It is a horizontal sectional view of a cell body part in a 2nd embodiment of the present invention. It is sectional drawing which shows the AA cross section of FIG. It is sectional drawing which shows the BB cross section of FIG. It is a perspective fragmentary view which shows an example of the cross-section of the cell main body in the conventional steel plate cell. It is sectional drawing of the cell main-body part which shows the path | route which the contaminated water which penetrate | invaded in the cell main body from the corrosion location of the cell shell leaks out to the open sea. It is sectional drawing of a cell main body which shows the state which formed the water shielding layer inside the cell shell.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a horizontal sectional view showing a part of a steel plate cell according to the first embodiment of the present invention, FIG. 2 is a sectional view taken along a line AA in FIG. 1, and FIG. It is sectional drawing in B section, Comprising: The steel plate cell 1 shown to these figures is utilized for the impermeable revetment of the waste sea surface disposal site constructed in a coastal sea area like the conventional thing demonstrated previously in FIG. It is what is done.

  As shown in FIG. 1, the steel plate cell 1 includes a cylindrical cell body 2 arranged in a plurality in the revetment normal direction and an arc portion 3 provided between the adjacent cell bodies 2. The arc part 3 is filled in a pair of arc-shaped arcs 3A and 3B respectively disposed on the outer sea side and the revetment inner side (waste sea surface disposal site side), and in a space formed inside these arcs. Each of the arcs 3A and 3B is composed of a stuffing material 3C, and both ends of the arcs 3A and 3B are connected to the outer peripheral surface of the cell shell 2A constituting the cylindrical outer shell of the cell body 2 with a known water-blocking structure. 4 are connected.

  As shown in FIG. 2, a concave portion 5A having a rectangular cross section extending in the direction of the seawall normal is excavated and formed in the impermeable seabed 5 where the steel plate cell 1 is installed. , Is placed on the foundation waste stone 6 laid in the recess 5A.

  Further, a water shielding material 7 is filled between the outer peripheral surface of the lower part of the cell shell 2A entering the concave portion 5A of the submarine ground 5 and the vertical wall surface of the concave portion 5A to block the water. Although not shown, the lower part of the arc part 3 provided between the adjacent cell main bodies 2 is also arranged in the recess 5A in the same manner as the cell main body 2, and the outer periphery of each of the arcs 3A and 3B. The lower portion of the surface and the vertical wall surface of the concave portion 5A are also shielded by the water shielding material 7.

  As shown in FIGS. 2 and 3, a composite water shielding layer 8 having a predetermined width d is formed in the vertical direction across the entire horizontal cross section of the cell shell 2 </ b> A. Filling material 10 is filled between 8 and the upper canopy 9 and between the composite water shielding layer 8 and the lower end of the lower cell shell 2A.

  As already described with reference to FIG. 11, if a difference in level occurs between the water levels on both sides of the cell shell 2A due to tide level fluctuations in the open sea, the cell shell 2A is orthogonal to the revetment normal as shown in FIG. A shear load F acts on the horizontal direction and the vertical direction, respectively.

  The direction of the shear load F shown in FIG. 2 indicates the direction when the outside sea side is lower than the water level inside the revetment, and when the water level on the outside sea side is higher than the inside of the revetment, It acts in the opposite direction to that shown in the figure.

  In the present embodiment, in order to share such a shear load F acting on the cell shell 2A also in the composite water-impervious layer 8, as shown in FIG. 1 and FIG. The layer 8 is composed of a high-rigidity impermeable layer 8A and a low-rigidity impermeable layer 8B that are adjacent to each other at a perpendicular boundary surface V orthogonal to the revetment normal and are alternately arranged in the direction of the revetment normal. .

  Here, as the highly rigid water shielding layer 8A, for example, a concrete hard water shielding material can be used, and as the low rigidity water shielding layer 8B, for example, a soft water shielding material such as asphalt mastic is used. Water material can be used.

  In the present embodiment, as shown in FIG. 2, the shear load F acting on the composite water shielding layer 8 is shared and supported by the high rigidity water shielding layer 8A and the low rigidity water shielding layer 8B. Creep deformation of the low-rigidity impermeable layer 8B can be prevented by the high-rigidity impermeable layer 8A.

  Further, when an earthquake occurs, the low-rigidity impermeable layer 8B absorbs the vibration of the cell shell 2A, and it is possible to suppress an excessive stress from acting in the high-rigidity impermeable layer 8A. Can be protected from damage such as cracks.

  As a result, it is possible to shield water between the upper portion and the lower portion inside the cell shell 2A by the composite water shielding layer 8 without reducing the strength of the cell body 2. In addition, although illustration is abbreviate | omitted, the composite water shielding layer of the structure similar to the composite water shielding layer 8 mentioned above can be formed also in the inside of the arc part 3. FIG.

  Incidentally, the water shielding material constituting such a composite water shielding layer is not limited to that of the above-described embodiment, and for example, an asphalt water shielding material, a concrete water shielding material, and a soil water shielding material. In addition, from among asphalt mats and water shielding sheets, one for high rigidity water shielding layer and one for low rigidity water shielding layer may be used, one each or a combination of several types. it can.

  In addition, the high-rigidity impermeable layer includes a reinforcing bar configured to carry a shear load acting in the horizontal direction perpendicular to the seawall normal and a shear load acting in the vertical direction in the impermeable layer. For example, it may be formed of a composite such as reinforced concrete or steel concrete in which a highly rigid member such as a steel frame is embedded.

  Next, FIG. 4 shows a modified example of the above-described embodiment. In this example, the composite water shielding layer 8 has an outer peripheral surface of the cell shell 2A inside the revetment of the existing steel plate cell 1 and seawater. This composite impermeable layer 8 is formed later in order to prevent the intrusion of contaminated water into the inside of the cell shell 2A when repairing a portion where the hole h is opened by corrosion due to exposure to wind and rain. Then, after opening the canopy 9 and removing the upper filling material 10 at the top, it is formed with a predetermined width in the vertical direction so as to close the hole h from the inside, and thereafter, the filling material is formed in the upper part of the composite water shielding layer 8. 10 is refilled.

  FIG. 5 shows still another modification of the above-described embodiment. In this example, the composite water shielding layer 8 is formed on the cell shell 2A so that the bottom surface thereof is adjacent to the foundation waste stone 6. It is formed on the inner bottom. Further, on the inner wall surface of the cell shell 2A, a water-impervious sheet 11 is affixed over the entire circumference between the composite water-impervious layer 8 and the canopy 9, and a hole is opened in the cell shell 2A due to corrosion or the like. In such a case, the water-impervious sheet 11 prevents entry of contaminated water into the filling material 10 side.

  Also, in the event that the water shielding sheet 11 leaks, the composite water shielding layer 8 formed at the inner bottom of the cell shell 2A prevents the water leakage, so that the pollution leaked from the waste sea surface disposal site. There is very little possibility that water will enter the foundation waste stone 6.

  In the first embodiment described above, the vertical width d (see FIGS. 2 and 3) of the composite water shielding layer 8 is the high rigidity water shielding layer 8A and the low rigidity water shielding layer. It can be set to a desired width according to the water shielding performance of the water shielding material used for 8B. Moreover, you may form such a composite water-impervious layer 8 in the upper and lower stages in the cell shell 2A.

  Next, FIG. 6 is a horizontal sectional view showing the cell main body portion in the second embodiment of the present invention, FIG. 7 is a sectional view showing the AA section of FIG. 6, and FIG. It is sectional drawing which shows -B cross section. The structure of this embodiment is the same as that of the first embodiment described above, except for the composite water shielding layer 8 '.

  In the present embodiment, a plurality of high-rigidity members 8'A made of a truss-structured steel frame are embedded in the water-impervious layer 8'B to form a composite water-impervious layer 8 '. As shown in FIGS. 6 and 8, these high-rigidity members 8 ′ A are provided on the inner side of the cell shell 2 </ b> A so that their longitudinal directions are parallel to the horizontal direction orthogonal to the seawall normal line. They are arranged at equal intervals in the line direction.

Further, both ends in the longitudinal direction of these high-rigidity members 8′A are connected to the inner wall surface of the cell shell 2A , respectively, and a shear load acting in the horizontal direction perpendicular to the revetment normal acting on the cell shell 2A. And a shear load acting in the vertical direction.

  In this embodiment, since the high rigidity member 8′A composed mainly of a truss structure steel frame resists the shear load acting on the cell shell 2A, the water shielding layer For 8′B, for example, it is effective to use an asphalt mastic or the like having a low rigidity and an excellent vibration damping effect during an earthquake.

  Further, when the high-rigidity member 8′A is made of steel as in this embodiment, the tensile stress acting in the composite water-impervious layer 8 ′ due to the shearing load is increased by the high-rigidity member 8′A. Therefore, a highly rigid water shielding material such as concrete that is fragile to a tensile load can be used for the water shielding layer 8'B.

  Further, the composite water-impervious layer 8 ′ has a vertical width d within the cell shell 2A, similar to the composite water-impervious layer 8 in the first embodiment described above, and the water-impervious layer 8 ′. The width can be set according to the water shielding performance of the water shielding material used for B. Moreover, you may form such a composite water-impervious layer on the inner side of the cell shell 2A in a plurality of upper and lower stages as necessary.

  Further, in the present embodiment, the high-rigidity member 8′A is constituted by a plurality of independent steel frames, but these high-rigidity members 8′A are connected to each other by a connecting member. You may integrate. In addition, the high-rigidity member used for the composite water-impervious layer only needs to have a structure capable of sharing the shear load acting in the horizontal direction perpendicular to the seawall normal acting on the cell shell and the shear load acting in the vertical direction. For example, such a composite water shielding layer may be made of reinforced concrete, steel concrete, or a hybrid that is embedded in a water shielding layer of waterproof concrete using reinforcing bars or steel frames as high-rigidity members.

  Further, the description of the countermeasure against water leakage from the arc steel plate to the inside thereof is omitted here, but it is possible to form a composite water shielding layer having the same structure as that of the composite water shielding layer 8 'in the arc portion. is there.

  In each of the first embodiment and the second embodiment, the foundation waste stone 6 is laid in the recessed portion 5A excavated and formed in the seabed ground 5, and the cell body 2 is placed thereon, The structure having a water shielding material 7 between the lower part of the outer peripheral surface of the cell shell 2A and the vertical wall surface of the recess 5A has been described, but the water shielding structure of the cell body of the present invention has such a structure. However, the present invention is not limited to this, and the water shielding structure of the cell body in the rooted steel plate cell can be similarly implemented.

  The water-impervious structure of the cell body of the present invention can be used when building a cell-type water-impervious revetment such as a waste sea surface disposal site by using a steel plate cell or an embedded steel plate cell.

DESCRIPTION OF SYMBOLS 1 Steel plate cell 2 Cell main body 2A Cell shell 3 Arc part 3A, 3B Arc 3C Filling material 4 Connection part 5 Submarine ground 5A Concave part 6 Foundation waste stone 7 Water-insulating material 8, 8 'Composite water-insulating layer 8A High-rigidity water-insulating layer 8B Low rigidity water shielding layer 8'A High rigidity member 8'B Water shielding layer 9 Canopy 10 Filling material 11 Water shielding sheet V Interface F Shear load

Claims (2)

A cell body water-blocking structure used for cell-type impermeable revetment where the cell bodies are connected by an arc part,
A composite impermeable layer consisting of a high-rigidity impermeable layer and a low-rigidity impermeable layer adjacent to each other at a perpendicular boundary perpendicular to the revetment normal, and arranged alternately in the direction of the revetment normal, is located inside the cell shell. In addition, the cell body is provided with a predetermined width in the vertical direction over the entire horizontal cross section. A cell body water-blocking structure used for cell-type impermeable revetment where the cell bodies are connected by an arc part,
A composite impermeable layer with a shear load acting in the horizontal direction perpendicular to the seawall normal and a highly rigid member that resists the shear load acting in the vertical direction is embedded inside the cell shell. Furthermore, it is formed with a predetermined width in the vertical direction over the entire horizontal section ,
A plurality of the high-rigidity members are provided, and the longitudinal directions thereof are horizontal and coincide with the direction perpendicular to the revetment normal direction, and are arranged at equal intervals in the revetment normal direction. The water-blocking structure of the cell main body characterized by being made .

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