JP6166550B2 - Embankment - Google Patents

Description

  The present invention relates to an embankment suitable for building a breakwater or a tide embankment that is provided on a coast or a river bank and prevents a water disaster caused by a tsunami or a flood, or for raising an existing embankment.

  Since Japan is located on the course of typhoons, typhoons hit every year, causing flooding due to river flooding. Also, in the Great East Japan Earthquake that occurred on March 11, 2011, the dyke broke down due to an unexpected large tsunami, and seawater crossed the levee, causing unexpected catastrophic damage. Even the constructed ones were found to be inadequate with existing breakwaters such as breakwaters and seawalls.

  For this reason, the construction of a dike that assumes a large tsunami is an urgent issue, and the existing dike is being raised or a new dike is being developed.

  For example, Patent Literature 1 includes a “steel pipe pile, a footing supported by the steel pipe pile, a wall body through hole disposed above the footing and penetrating in an in-plane direction. And a precast wall body having a wall body and a pipe on the inner surface thereof, wherein the footing has a footing through-hole penetrating in the thickness direction, and the footing through-hole is formed on the inner surface of the footing through-hole. A tube is provided, the footing sheath extends to a position above the upper surface of the footing, the steel pipe pile is inserted into the footing sheath, and the footing sheath is the wall sheath sheath tube of the precast wall body. And a gap between the footing sheath and the pipe and the steel pipe pile inserted into the footing sheath is filled with a grout material.

  In addition, various types of dikes have been proposed in the past, and some of them have a double wall structure. For example, Patent Document 2 states that “a required number of support piles that are driven in a row in a row and are installed on the support pile facing the open sea side, and introduction gaps are formed at predetermined intervals in the row direction. A first wave breaker, and a second wave breaker that is positioned on the support pile on the calming sea area side of the first wave breaker wall and attached substantially continuously in the row direction, A curtain-type breakwater characterized in that an attenuation space is formed between the first and second breakwater walls is described.

  Patent Document 3 states that, “A raised levee for raising existing levees installed in various water areas such as rivers and coasts, having an approximately U-shaped cross section and an opening in the direction of the existing levee, and an upper end of the existing levee A flat plate connecting body that forms a hollow portion between the flat plate connecting portion, a positioning portion that protrudes inside the flat plate connecting body, abuts against an upper end portion of the existing lantern, and determines a vertical position with respect to the existing lantern, and the flat plate coupling "A raised levee characterized by comprising fixing members for fixing both side plates of the body to the upper both side walls of the existing levee" is described.

  On the other hand, during the reconstruction of the earthquake disaster, the lack of concrete supply to the coastal area, the difficulty of land transportation of large and heavy materials due to road conditions, and increased transportation costs have been screamed. These points need to be taken into consideration when constructing.

Japanese Patent No. 5024489 JP 2000-204530 A JP 2006-45814 A

  When building new breakwaters and seawalls in the affected areas caused by the Great East Japan Earthquake, and building new breakwaters and seawalls in coastal areas other than the affected areas, or improving existing dikes Needless to say, the high-performance and high-quality dike can be used, but as mentioned above, the shortage of concrete supply, road conditions in coastal areas where road development is not progressing, transportation costs, construction costs, urgency, etc. are also considered. However, the amount of concrete used is less than in the past, and it is necessary to make it easy to carry materials and components on land and to be easily constructed. However, there is almost no such thing.

  What is described in Patent Document 1 is a hybrid type using a precast member of a steel / concrete composite structure, considering durability, workability, response to a large tsunami, etc. Compared to, the size and weight have been reduced, but the walls and footings are made of large and heavy precast concrete slabs and are not necessarily easily transported by land. Moreover, it cannot be said that the response to the shortage of concrete supply is sufficient.

  The curtain-type breakwater described in Cited Document 2 has a double wall structure consisting of a first breakwater and a second breakwater, but calms at a port against normal waves from the open sea. However, it is not strong enough to cope with a large tsunami.

  The raised levee described in Patent Document 3 is also of a double wall structure having both side plates, but is simply raised by assembling a precast dam material on an existing levee and covering it with a substantially U-shaped dam. Therefore, the strength of the entire dike is not much different from that of the existing dike, and it is not supposed to cope with a large tsunami.

  The present invention has been made in view of the background and problems as described above, and is strong and high-quality capable of dealing with a large tsunami. The purpose is to provide a dam body that suppresses the amount of use as much as possible.

  One of the present inventions (first invention) is “a dam body in which double wall units are arranged in the dam body continuous direction to form a wall surface, and the steel pipe piles arranged in two rows and supported by the steel pipe piles. And a double wall unit disposed above the footing. The double wall unit connects two precast plates arranged in parallel at a predetermined interval. It is connected with a support column, and the lower end portion of the connection support column is a connecting body with the steel pipe pile.

  The levee body of the present invention is roughly divided into a steel / concrete composite structure including a steel pipe pile serving as a foundation pile, a footing supported by the steel pipe pile, and a double wall unit disposed above the footing. It is a hybrid type.

  The steel pipe pile is the same as the conventional one. The footing may be a conventional on-site construction or may include a unitized part produced at the factory. If it includes a unitized part, it is possible to improve the footing quality and facilitate footing construction.

  The double wall unit is formed by connecting two precast plates arranged in parallel at a predetermined interval with a connecting column, and the lower end of the connecting column is a connecting part with the steel pipe pile. It is manufactured at the factory. Since the unit manufactured at the factory is used, the quality can be made stable and the quality can be improved, and the land transportation efficiency and construction efficiency can be improved.

  Examples of the precast plate include a reinforced concrete plate, a steel reinforced concrete plate, a prestressed concrete plate, a steel / concrete composite plate, a high-strength concrete plate, a fiber-reinforced concrete plate, a fiber-reinforced resin plate, and a resin / concrete composite plate. Moreover, as a connection support | pillar, in addition to what consists of steel materials, such as a H-shaped steel, a square steel pipe, a truss structure material, and a corrugated steel plate, it consists of a precast concrete thing, a ceramic thing, and a composite of concrete and carbon fiber. Things. By arranging the double wall units in the bank body continuous direction, the entire wall surface of the bank body or a part of the wall surface is formed.

  In the bank of the present invention, as described above, the flood barrier is a double wall structure. Of the precast plates with a double wall structure, the front side (waterside) precast plate that serves as the tension member plays the role of a wave pressure plate. To play a role.

  On the other hand, the precast plate on the back side (land side) serving as a compression side member plays a role as a compression plate, and bears a bending compression force and contributes to improvement in rigidity. Moreover, when a connection support | pillar consists of steel materials, it also plays the role as a cover board at the time of forming the sealed space which protects this from salt damage. In this way, efficient utilization of members can be realized by providing both the function as the compression plate and the function as the cover plate in the precast plate on the back side (land side).

  The connecting struts connect the front-side precast plate and the back-side precast plate, and bear the role of bearing a shearing force. By connecting the two precast plates with connecting struts to form a wall unit, the entire unit can be reduced in weight, and even a structure with a high wall height can be easily transported by land, and on-site construction can be simplified.

  As described above, by using a wall unit and making it a double wall structure, it is possible to form a lightweight and strong barrier while reducing the burden on the connecting struts, thereby reducing the amount of concrete used. Is also possible. And, by using a member mainly made of steel on the tension side and a hybrid type using a member mainly made of concrete on the compression side, it should be efficient and effective taking advantage of each material property. Can do.

  The connecting strut is preferably made of H-section steel. With the double wall structure as in the present invention, even a load that cannot be borne by the H-section steel alone can be borne, so that an H-section steel that is inexpensive and easily available can be used.

  And if it is a unit in which H-shaped steel and two wall panels are connected at the factory, it is much lighter than conventional precast concrete walls, so it is easy to transport on land, and the vehicle for transporting precast concrete walls is large. It is possible to solve problems in field construction, such as limiting the transportation route and increasing the size of the clean required for on-site installation.

  The footing uses a footing unit, and the footing unit is preferably a box frame framed with a steel material.

  In the present invention, from the viewpoints of building a strong dam body with high-quality members, ease of land transportation of members, workability, control of concrete used, etc., hybrid type units such as double-wall units based on steel / concrete synthesis It is characterized by using. Therefore, it is preferable that the footing is of a hybrid type, and at least a part thereof is unitized to form a footing unit. The structure of the footing unit is not particularly limited. In the present invention, the footing unit is a box frame made of steel, for example, and concrete is placed around the box frame at the construction site to complete the footing. The box frame does not necessarily need to be made of steel, and may be made of various concretes such as fiber reinforced concrete or resin such as fiber reinforced resin.

  Moreover, it is preferable that the said footing is divided into three with steel materials, and the center division becomes a hollow part. Of the three sections, the sections on both sides are directly below the steel pipe pile, the wall unit is connected to the steel pipe pile in the footing, and the section is filled with concrete. The central section where the steel pipe pile is not directly below is hollow. The reason for the hollowness is that the amount of concrete used is reduced and the unit weight during transportation is reduced. Even if it is hollow, the double wall and the connecting column are integrated and resist external force, so there is no problem in strength or durability. The term “hollow” as used in the present invention means that there is no hardened cement body such as mortar or concrete, and includes not only space but also earth and sand, lightweight materials, energy absorbers, and the like. .

  Moreover, it is preferable that the said footing coat | covers the circumference | surroundings of the said footing unit which arranged two H-shaped steels side by side and formed the box frame with concrete.

  As described above, the box frame may be formed of concrete or resin. However, if two H-shaped steels are arranged and side walls, a bottom plate, a ceiling plate, and a partition plate are made of steel plates to form a steel box frame, This is preferable because advantages such as a footing unit that can be easily connected on site can be obtained.

  The upper end portion of the steel pipe pile is inserted into the footing, the connection portion of the connecting column is inserted into the pipe at the upper end portion of the steel pipe pile, and the periphery of the steel pipe pile is solidified with concrete to form the double wall. It is preferable that the unit, the footing and the steel pipe pile are integrated.

  As described above, in the dam body according to the present invention, the double wall unit and the steel pipe pile directly below are connected within the footing. In this case, the connection structure as described above is preferable.

  That is, in order to make the bank body strong, the double wall unit installed above the footing, the footing, and the steel pipe pile supporting the footing need to be firmly integrated in the vertical direction. However, in the present invention, the connecting portion at the lower end of the connecting column in the double wall unit is inserted into the pipe at the upper end of the steel pipe pile in the footing, and the lower end of the double wall unit and the steel pipe pile are overlapped and connected in the footing. Therefore, a double wall unit, a footing, and a steel pipe pile can be firmly integrated.

  Another one of the present invention (second invention) is “a levee body in which double wall units are arranged in a dam body continuous direction to form a wall surface, and steel pipe piles arranged in a row, a steel shell unit, An embankment comprising a foundation portion made of filled concrete and supported by the steel pipe pile, and a double wall unit disposed above the foundation portion, wherein the double wall unit has a predetermined interval A dike body in which two precast plates arranged in parallel with a gap are connected by a connecting column, and the lower end of the connecting column is a connecting part with the steel pipe pile ” It is.

  The above-mentioned another invention (first invention) assumes a bank structure in which steel pipe piles are arranged in two rows so as to extend in the bank body continuous direction. ) Assumes a dam structure in which steel pipe piles are arranged in a row. Although it is common to use steel pipe piles and double wall units, footing is not a requirement when steel pipe piles are arranged in a row. The wall height of the double wall unit does not have to be so high, and when the levee body is constructed where the ground is good, the steel pipe pile may be in a single row, and the present invention (second invention) is applied in such a case. The

  In this invention (2nd invention) when this steel pipe pile is arranged in a line, a steel pipe pile and a double wall unit are the same as the above-mentioned thing, It replaces with a footing, and uses a steel shell unit and filling concrete. The foundation part supported by this steel pipe pile is used. As in the case of the footing, a double wall unit is provided above the foundation. The difference between the footing and the foundation mentioned in the present invention is the foundation constructed by connecting the pile heads of steel pipe piles arranged in multiple rows vertically and horizontally, while the foundation is in the direction of the levee body. It is a point that is a foundation constructed by connecting pile heads of steel pipe piles aligned in a row in the continuous direction of the bank.

  In the base portion, a steel shell unit is used as one corresponding to the footing unit. Similar to the footing unit, the steel shell unit has a box shape, and is a unit formed by covering a box frame (steel shell) made of steel with concrete. In the case of this invention as well, by forming the dam body using units manufactured at the factory, such as steel shell units and double wall units, the quality can be made stable and high quality, and the land transportation efficiency and construction can be improved. Efficiency is improved and the amount of concrete used can be reduced.

  In the second aspect of the invention, the upper end of the steel pipe pile is inserted into the foundation part, the connection portion of the connecting column is inserted into the pipe at the upper end of the steel pipe pile, and the periphery of the steel pipe pile is solidified with concrete. It is preferable that the double wall unit, the base portion, and the steel pipe pile are integrated. This is the same as in the case of the first invention using the above footing as an essential requirement.

  Moreover, it is preferable that the said connection support | pillar consists of H-section steel. This is the same as in the case of the first invention.

  Moreover, it is preferable that the foundation part which consists of the said steel shell unit and filling concrete has a hollow part. In the footing according to the first aspect of the present invention, it is preferable to provide a hollow part in the footing. However, for the same reason, it is preferable to provide a hollow part in the base part.

  Regardless of the footing or the foundation, the steel pipe piles are juxtaposed at a predetermined interval, so that there is always a portion directly above the steel pipe pile with the steel pipe pile immediately below and a portion without the steel pipe pile directly below. The part directly above the steel pipe pile with the steel pipe pile must have a function of covering the steel pipe pile to prevent rust, so it is necessary to cast concrete, but there is no need for the part without the steel pipe pile directly below. Since sufficient strength can be ensured elsewhere, even if it is hollow, no major problem occurs.

  As described above, the term “hollow” as used in the present invention means “no concrete or mortar is placed”, and in addition to space, fillers such as earth and sand, lightweight materials, and energy absorbing materials are filled. It may be.

  Also, the space between the two precast plates in the double wall unit may be filled with foamed urethane, foamed polystyrene, earth and sand, recycled materials such as waste materials, or shock absorbers. It may be left. By keeping the space, it becomes easy to inspect the inside of the double wall unit for maintenance after completion.

  The levee body of the present invention is constructed by assembling a plurality of units manufactured at the factory on site, so it is strong and high-quality that can cope with a large tsunami, has good workability, and uses concrete. Since the hybrid type has a steel / concrete composite structure with the amount reduced as much as possible, it can be made lighter with less concrete usage taking advantage of the characteristics of each material, and land transportation becomes easy. And it can solve recent problems such as insufficient supply of concrete to construction sites.

It is a perspective view which shows one Embodiment of the bank body of this invention (1st invention). (A) is the figure seen from the front side (waterside side), (b) is the figure seen from the back side (land side). It is a figure which shows an example of the structure of the bank body of this invention (1st invention) using a joining unit. (A) is a front view, (b) is a plan view, and (c) is a side view. It is a figure which shows the example of a double wall unit. (A)-(d) is the example which used the H-section steel as a connection support | pillar, (a) is a perspective view which shows the whole, (b) is a front view, (c) is a top view, (d) is a side view FIG. (E) shows a side view and a plan view of an example using a truss as a connecting post, and (f) shows a side view and a plan view of an example using a corrugated steel web as a connecting post. It is a figure which shows the example of a footing unit and a joining unit. (A) is a perspective view showing a footing unit, (b) is a perspective view showing an upper member of the joining unit, (c) is a perspective view showing a lower member of the joining unit, and (d) is under the footing unit and the joining unit. It is the perspective view which constructed the foundation frame of the levee body by installing a member in the pile head of a steel pipe pile. It is a figure which shows the connection structure which connected the footing unit and the lower member (block) of the joining unit with the connection steel material by H-section steel. (A) is a top view, (b) is a connection plan view of a double wall unit portion, and (c) is a front view. It is a perspective view which shows the construction example of the bank body of this invention which used the jointing unit which consists of the footing unit by H-section steel, and the above-mentioned two upper and lower members, and used H-section steel as connection steel material. The process until the foundation completion (primary concrete construction completion) is shown. (A) is a steel pipe pile construction process, (b) is a footing installation process, (c) is a lower member (block) installation process in the joining unit, and (d) is a lower member in the footing unit and the joining unit. The connection process of (block), (e) shows the completion process of the foundation by placing primary concrete. It is a perspective view which shows the construction example of the bank body of this invention which used the jointing unit which consists of the footing unit by H-section steel, and the above-mentioned two upper and lower members, and used H-section steel as connection steel material. The process from the completion of the foundation to the completion of the embankment of the present invention is shown. (F-1) and (f-2) show the standing process of the double wall unit (1st wall panel) and the upper member (2nd wall panel) of a joining unit in a footing. (F-1) is a view from the front, and (f-2) is a view from the back. (G-1) and (g-2) show the placement process of secondary concrete. (G-1) is a view from the front, and (g-2) is a view from the back. (H) shows a soil backfilling step (road building step). It is a figure which shows an example of the structure of the bank body of this invention (2nd invention) using the base part by a steel shell unit. (A) is a front view, (b) is a side view, (c-1) is a plan view at position A, and (c-2) is a plan view at position B. FIG. It is a figure which shows an example of a steel shell unit. (A) is the perspective view of a steel shell unit, (b) is the perspective view which installed the steel shell unit in the upper end part (pile head) of a steel pipe pile. It is a perspective view which shows the example of construction of the bank body of this invention (2nd invention) at the time of arranging a steel pipe pile in a line. (A) is a steel pipe pile construction process, (b) is a steel shell unit installation process, (c) is a double wall unit installation process, and (d-1) is a concrete filling process ( The basic part completion process). (D-2) is the reference figure which showed clearly the placement range of the filling concrete in a foundation part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below.

  First, the present invention according to the first invention will be described based on the drawings of FIGS.

  FIG. 1 is a perspective view showing an embodiment of a bank body of the present invention (first invention). (A) is the figure seen from the front side (waterside side), (b) is the figure seen from the back side (land side).

  The bank body 1 of the present invention is constructed on an existing bank 2. A double wall unit 4 is disposed above the footings 6 supported by the steel pipe piles 5 provided in two rows in the bank body continuous direction at a predetermined interval and arranged in parallel at a predetermined interval. (First wall panel 4-1) is provided. In this example, a joining unit 8 for reinforcement used as necessary is provided between the adjacent footings 6 and 6, and a double unit similar to the double wall unit is also provided above the joining unit 8. A wall panel 4 (second wall panel 4-2) is provided. Thus, it is preferable to parallel the footings 6 at a predetermined interval in terms of saving the amount of concrete used and reducing the size of the heavy equipment for construction. In this case, it is preferable to provide the joining unit 8 between the adjacent footings 6 and 6 from the viewpoint of ensuring water tightness as well as reinforcement.

  However, providing the joining unit 8 is not an essential requirement, and the adjacent footings 6 and 6 may be connected by a block such as a concrete block or a steel block, a steel material such as a steel bar, or other members. In this case, since the second wall panel 4-2 is eliminated, in this case, the first wall panel 4-1 is wider than the case where the second wall panel 4-2 is used, and the first wall panel 4 is used. -1 are connected to each other in the bank body continuous direction to form the wall surface of the bank body 1 (not shown).

  The double wall panel 4 has a double wall structure composed of two precast plates supported by a connecting column, and a space is provided between the precast plates. In this example using the joining unit 8, one of the double wall panels 4 is a double wall first wall panel 4-1 installed above the footing 6 and made of two precast plates. As another one of the double wall panels 4, the joining unit 8 is also provided with a second wall panel 4-2 having a double wall structure similar to the first wall panel 4-1, and these panels are alternately arranged. The wall surface of the bank body 1 is formed by being arranged in the bank body continuous direction.

  The footing 6 is provided with a projecting steel material 7 (for example, a perforated steel plate gibel, an H-shaped steel, a stud gibel) for firmly joining the adjacent joining unit 8. Further, the back side of the wall surface of the bank 1 is a road 3.

  The first wall panel 4-1 of the double wall unit and the second wall panel 4-2 of the joining unit 8 are vertically long and match the width of the footing 6 and the lower part of the joining unit 8 as shown in the figure. .

  As described above, when the joining unit 8 is not used, the width of the first wall panel 4-1 is wider than this.

  In this example, an example of one step in the height direction is shown, but a plurality of steps in the height direction can be used in consideration of the required wall height, production efficiency, land transportation efficiency, construction efficiency, and the like.

  FIG. 2 is a diagram showing an example of the structure of the bank body of the present invention (first invention) using the joining unit 8. (A) is a front view, (b) is a plan view, and (c) is a side view.

  The steel pipe pile 5 consists of a waterside steel pipe pile and an inland side steel pipe pile, and these are provided in two rows in parallel at a predetermined interval toward the continuous direction of the dam body. The interval is preferably about 250 to 450 cm. Each pair of steel pipe piles 5 and 5 corresponding to the two rows is provided at a constant interval of 150 to 600 cm substantially perpendicular to the continuous direction of the bank. And the double wall panel 4 (1st wall panel 4-1) of the double wall unit 14 supported by the connection support | pillar 9 via the footing 6 is installed above the steel pipe pile 5 of the front side (waterside side). ing.

  As shown in the drawing, the footings 6 are provided at predetermined intervals in accordance with the arrangement of the steel pipe piles 5. In this example, each footing 6 is made using a footing unit composed of a box frame made of a steel material, and is divided into three by a partitioning steel plate 11. The sections on both sides where the steel pipe piles 5 are located immediately below are filled with concrete 13, and the central section where the steel pipe piles 5 are not located directly below are the hollow portions 12. The reason for making it hollow is to reduce the weight and facilitate land transportation.

  A joining unit 8 is provided on the front side (waterside side) between the adjacent footings 6, 6, and forms a foundation in which the footings 6, 6 and the joining unit 8 are integrated. Similar to the double wall unit 14, the joining unit 8 includes an upper member provided with the double wall panel 4 (second wall panel 4-2) supported by the connecting column 9 and an embedment for connecting the upper member. It consists of upper and lower two members of a lower member consisting of a block 16 provided with an inner mold 21. The blocks are concrete blocks, steel blocks, steel / concrete composite blocks, and the like.

  The upper and lower two members are connected by the connecting portion 10 of the upper member being inserted into a hole 22 formed by the embedded inner mold 21 of the lower member and fixed with concrete. The second wall panel 4-2 is connected to the first wall panel 4-1, and the block 16 is connected to the adjacent footing 6.

  The connection between the footing 6 and the joining unit 8 uses a connection steel material 7. As the connection steel material, in addition to a perforated steel plate gibber, an H-shaped steel and a high-strength bolt can be used together. The connection using the H-shaped steel is preferable because there is a merit that positioning at the time of erection becomes easy and the process can be shortened. As shown in the figure, the height of the block 16 is the same as the height of the footing 6, and the steel pipe pile 5 and the embedded formwork 21 are alternately arranged.

  Since there is no steel pipe pile directly under the joining unit 8, it may be of any size that can perform the connection function. As shown in the figure, the length of the block 16 in the vertical direction (direction from the water side to the inland side) is footing. It is shorter than 6. In this example, it is matched with the front side (waterside) section in the footing divided into three sections.

  Since the joining unit 8 is provided with the second wall panel 4-2 supported by the connecting strut 9, the joining unit 8 composed of the two members transmits the load from the strut without the steel pipe pile to the footing. Play a role. That is, in the prior art, it was considered that the combination of the allocation of the foundation (steel pipe pile) and the main member (connection strut) was the most efficient in terms of workability and cost. It is not necessary to match the allocation intervals of the members. Therefore, it becomes possible to set the foundation and the main member to an optimal span allocation according to workability and cost. As a result, even in a heavy load case, it is not necessary to increase the number of foundations, and an inexpensive H-section steel can be selected as the main member, so that the total cost can be reduced.

  Moreover, by using the unitized one, quality can be ensured, the amount of on-site concrete can be reduced, and the construction efficiency can be improved.

  Above the front side (waterside) section of the three partitioned footings 6, a first wall panel supported by a connecting column 9 whose bottom end is a connection 10 with the steel pipe pile 5. A double wall unit 14 with 4-1 is provided. The double wall unit 14 is a unit composed of the double wall panel 4 and the connection column 9, and two precast plates are connected by the connection column 9, and a space is formed between the precast plates. Since the wall surface of the levee body is formed by the double wall unit, quality can be ensured, construction efficiency can be improved, and the amount of concrete used can be reduced.

  The space is used to reduce the weight and to facilitate inspections for maintenance after the completion of the bank. The first wall panel 4-1 is attached to the connecting column 9 by a headed stud.

  As shown in the drawing, the upper end portion of the steel pipe pile 5 immediately below the footing is inserted into the footing 6. And the 1st wall panel 4-1 in the double wall unit 14 is provided in the lower end in contact with the upper surface of the footing 6, and the connection part 10 of the connection pillar 9 lower end is inserted in the pipe of the steel pipe pile 5 upper end part, The steel pipe pile 5, the footing 6, and the double wall unit 14 are integrated by hardening the periphery with concrete.

  An upper member having a second wall panel 4-2 supported by the connecting column 9 is provided above the block 16 (lower member) in the joining unit 8. As described above, the upper member of the joining unit 8 is also a double wall unit including the connection column 9 and the second wall panel 4-2 supported by the two precast plates, like the double wall unit 14. is there.

  The 2nd wall panel 4-2 is also attached to the connection support | pillar 9 with the stud with a head. Moreover, the connection part 10 of the lower end part of the connection support | pillar 9 in an upper member is inserted and fixed to the hole 22 formed in the embedment inner mold 21 in the block 16 which is a lower member, and the upper and lower members are connected. The width of the second wall panel 4-2 is the same as the total width of the block 16 and the padded concrete placed on both sides thereof.

  As shown in the figure, the first wall panel 4-1 and the second wall panel 4-2 have the same height, and are alternately arranged in the bank body continuous direction to form the wall surface of the bank body 1. . The alternately arranged footings 6 and the blocks 16 of the joining unit 8 are connected by padded concrete, but the gap between the first wall panel 4-1 and the second wall panel 4-2 is blocked by a water stop material. The water-tightness is ensured. The water-stopping material is not particularly limited as long as it is a water-stopping material that has been conventionally used for a gap between panels.

  The double wall panel 4 comprising the first wall panel 4-1 and the second wall panel 4-2 is composed of two precast plates (RC plate, SRC plate, steel / concrete composite plate, etc.), and these are the connecting struts. 9 having a double wall structure supported by 9 (H-shaped steel, square steel pipe, truss structure material, corrugated steel plate, concrete square bar, etc.). The two precast plates may be of the same plate thickness, but with different plate thicknesses such that the one placed on the inland side of the bank is thicker than the one placed on the waterside side. But you can. The plate thickness is designed according to conditions such as wave pressure, tensile force, and compressive force.

  The use of the double-wall panel 4 is also in consideration of the ease of land transportation due to weight reduction and the reduction of the amount of concrete used, but from the viewpoint of mechanical action effect, it is not better to have a double-wall structure The rigidity of the member can be increased efficiently compared to the structure.

  Among the double walls, the wall panel (precast version) placed on the front side (waterside side) receives a tsunami directly as a wave pressure version and transmits the load to the main member (connecting column 9), as a main member Also serves as a role. Since it is a member on the tension side, it is better to use a precast plate with many steel materials such as reinforcing bars.

  The back side (inland side) wall panel (precast version) is a compression plate that bears the bending compression force and contributes to the improvement of rigidity. In addition, when the connecting strut 9 is made of steel, it is sealed to protect it from salt damage It also serves as a cover plate that becomes the back wall when forming the space. Therefore, a precast plate mainly composed of concrete is preferable.

  As described above, as can be seen from the above example of the present invention (first invention), the double wall unit 14 essential for building the bank body, the joining unit 8 used as a suitable one, and the double wall panel 4 provided in these units. Since the footing 6 using a footing unit used as a suitable unit is a unit of a hybrid type of steel / concrete composite structure, it is lightweight and high-performance utilizing the characteristics of each material. The amount of concrete used can be reduced. In addition, since it is a relatively light and small to medium size unit, it can be easily transported by land and has good workability.

  If the dam body is formed according to the basic technical concept of the present invention such as (A) a hybrid structure, (B) a double wall structure, and (C) a construction by connecting a plurality of units, the object of the present invention can be achieved effectively. Can do. As described above, the present invention is a combination of the technical ideas of (A) to (C) with respect to the problems specific to the present invention.

  FIG. 3 is a diagram illustrating an example of the double wall unit 14. (A)-(d) is the example which used the H-section steel as a connection support | pillar, (a) is a perspective view which shows the whole, (b) is a front view, (c) is a top view, (d) is a side view FIG. (E) shows a side view and a plan view of an example using a truss as a connecting post, and (f) shows a side view and a plan view of an example using a corrugated steel web as a connecting post.

  As shown in FIGS. 3A to 3D, the double-wall unit 14 has a hybrid-type double-wall structure, and two vertically long precast plates are parallel to the connecting column 9 (H-shaped steel 18). A double wall panel 4 is mounted. And the lower end part of the connection support | pillar 9 which does not have the double wall panel 4 is the connection part 10. FIG. Moreover, the double wall panel 4 and the connection support | pillar 9 are couple | bonded by the stud 15 with a head so that the part may be shown in the square frame A in a figure.

  The length of the connecting strut steel material 9 is about 250 to 1000 cm. The dimensions of the double wall panel 4 are about 150 to 800 cm in length, 150 to 300 cm in width (width), and about 15 to 30 cm in thickness. The width (width) is designed in consideration of the width of the footing 6 and the distance between the footings 6 and 6. When the joining unit 8 is used, the width (width) of the first wall panel and the width (width) of the second panel are designed in consideration of the width of the block 16 and the like.

  The distance between the two precast plates in the double wall panel 4 is about 40 to 200 cm from the viewpoints of ensuring the inspection space inside the double wall panel 4, ensuring the rigidity of the double wall panel 4, restrictions on the size of land transportation, etc. Is preferred.

  This double wall unit 14 is manufactured in a factory and transported to a construction site. Because of this configuration, it is lighter and easier to land transport than conventional wall panels. Also, the amount of concrete used for production is small.

  The connecting struts 9 are preferably H-shaped steel for reasons of ease of processing, availability, and low cost, but a truss shown in FIG. 3 (e) or a corrugated steel web shown in FIG. 3 (f) is used. It is possible and not particularly limited.

  Further, when the height of the dam body 1 is low and the connecting strut 9 does not require high strength, or when there is a surplus in the transport weight of the double wall unit 14, aluminum is used instead of the connecting strut 9 made of steel. It is also possible to use a connecting strut 9 made of an alloy or a connecting strut 9 made of concrete (reinforced concrete, steel reinforced concrete, prestressed concrete, etc.).

  FIG. 4 is a diagram illustrating an example of the footing unit 6-1 and the joining unit 8. (A) is a perspective view showing a footing unit 6-1, (b) is a perspective view showing an upper member of the joining unit 8, (c) is a perspective view showing a lower member of the joining unit 8, and (d) is a footing unit. It is the perspective view which constructed the foundation frame of the bank body 1 by installing the lower member of 6-1 and the joining unit 8 in the pile head of the steel pipe pile 5. FIG.

  Although it is not essential to use a footing unit and a joining unit, it is preferable to use these from the viewpoints of construction efficiency and reduction of the amount of concrete used.

  In the footing unit 6-1 shown in FIG. 4A, a box frame 17 is formed by an H-shaped steel 18 and is partitioned into three by a partitioning steel plate 11. Some partitioning steel plates 11 are made of H-section steel 18, and both ends play a role as connecting steel materials. A ceiling steel plate 19 having a headed stud (not shown) is attached to the central compartment and is covered with concrete 13. The inside is a hollow portion 12. Both ends are also covered with concrete 13.

  This hybrid type footing unit 6-1 is manufactured at a factory. If such a footing unit 6-1 is used to construct the footing 6, construction efficiency can be established and a high-quality one can be obtained. In addition, there is land transportation from the factory to the construction site, and the amount of concrete used can be reduced.

  The upper member of the joining unit 8 shown in FIG. 4B is composed of the double wall panel 4 (second wall panel 4-2) and the connection column 9, and the lower end of the connection column 9 is the connection unit 10. The structure is the same as the double wall unit 14 described above.

  The lower member (block 16) of the joining unit 8 shown in FIG. 4 (c) has two H-shaped steels 18 serving as connecting steel members connected to the short pipes of the steel pipes serving as the embedded inner form 21 by means of headed studs (not shown). The block 16 is made by placing precast concrete as shown in the figure. A hollow portion 12 is formed in the short pipe. The embedded inner form 21 may be a steel or resin partition plate in addition to the steel pipe short pipe shown here.

  FIG. 4D shows a cast-in-place concrete placement in which the footing unit 6-1 shown in FIG. 4A and the lower member (block 16) of the joining unit 8 shown in FIG. It is a figure which shows the previous bank body frame structure. The description of the ground is omitted for easy understanding.

  The sections on both sides of the footing unit 6-1 are respectively inserted into the pile heads of the pile steel pipe 5, the footing units 6-1 are installed on the pile heads, and joined between adjacent footing units 6-1 and 6-1. A lower member (block 16) of the unit 8 is installed. And the H-shaped steel 18 of the connection steel material which each protrudes is fastened with the high strength volt | bolt 23, and the footing unit 6-1 and the lower member (block 16) of the joining unit 8 are connected.

  FIG. 5 corresponds to FIG. 4 (d), and shows a connection structure in which the footing unit 6-1 and the lower member (block 16) of the joining unit 8 are connected by a connecting steel material of H-section steel 18. is there. (A) is a top view, (b) is a connection plan view of the double wall unit 14 portion, and (c) is a front view.

  The footing 6 is made by using a footing unit 6-1 in which a box frame 17 is formed of an H-shaped steel 18, and the footing unit 6-1 is covered with concrete 13. Both ends of the H-shaped steel, which also serves as the partition steel plate 11, are made to project so as to serve as a connecting steel material (see FIG. 4 (a)).

  Above the footing 6, a double wall unit 14 having a double wall structure supported by a connecting column 9 (H-shaped steel 18) is erected. As shown in FIG. 5B, a hollow portion 12 is formed between the double wall panels 4. The connecting portion 10 at the lower end of the connecting column 9 is inserted into the pipe at the upper end of the pile steel pipe 5 in the footing 6, and the steel pipe pile 5, the footing 6 and the double wall unit 14 are integrated by solidifying the periphery with concrete 13. .

  The joining unit 8 is composed of two upper and lower members as shown in FIGS. 4B and 4C and is installed between the adjacent footings 6 and 6. Then, the H-shaped steel 18 of the connecting steel projecting on the footing 6 and the H-shaped steel 18 of the connecting steel projecting on the lower member (block 16) of the joining unit 8 are fastened with the high-strength bolts 23, The footing 6 and the joining unit 8 are connected by placing the interstitial concrete 20. Between the first wall panel 4-1 of the double wall unit 14 and the second wall panel 4-2 of the upper member of the joining unit 8, a gap is closed with a water stop material, and water tightness is ensured.

  In this way, the joining unit 8 is composed of two upper and lower members using the embedded inner mold 21, and the connecting steel material is an H-shaped steel material, and the footing 6 and the joining unit 8 (lower member of the block 16) are connected. This levee body structure of the present invention is suitable for construction of a large dam body because the member weight can be suppressed.

  FIGS. 6 to 7 show examples of construction of the levee body 1 of the present invention using the H-shaped steel 18 as a connecting steel material, using the footing unit 6-1 made of the H-shaped steel 18 and the joining unit 8 composed of the above-mentioned two upper and lower members. It is a perspective view shown.

  FIG. 6 shows the process until the foundation 25 is completed (primary concrete 26 is finished). (A) is the construction process of the steel pipe pile 5, (b) is the installation process of the footing 6-1, (c) is the installation process of the lower member (block 16) in the joining unit 8, (d) is the footing unit. 6-1 shows a connecting process of the lower member (block 16) in the joining unit 8, and (e) shows a completion process of the foundation portion 25 by placing the primary concrete 24.

  As shown to Fig.6 (a), the pile construction by the steel pipe pile 5 is carried out to the existing levee 2, and it arranges at predetermined intervals in 2 rows. The pile head of the steel pipe pile 5 is put out about 100 cm above the ground. In the pile, a bottom plate is provided at a depth of about 200 cm, and on-site cast concrete is filled into the pile head pile. In addition, the pile head is installed with a stopper (steel plate) by field welding. After driving the steel pipe pile 5, the height is adjusted by cutting the pile head or the like in some cases.

  Next, as shown in FIG. 6 (b), the footing unit 6-1 made of a box frame manufactured at the factory and transported to the construction site is dropped into the pile heads of a pair (two) of steel pipe piles 5 and 5. The upper end portion of the steel pipe pile 5 is made to enter the footing 6. In the footing unit 6-1, as shown in the figure, a connecting steel material made of an H-shaped steel 18 protrudes from the side surface of the footing unit 6-1.

  Next, as shown in FIG.6 (c), the lower member (the connection steel material which has the embedment inner formwork 21 and consists of the H-section steel 18 among the upper and lower two-member joining units 8 manufactured in the factory and transported to the construction site. The protruding block 16) is placed between the footings 6 and 6. The connecting steel H-shaped steel 18 projecting from the footing unit 6-1 and the connecting steel H-shaped steel 18 projecting from the lower member are arranged to face each other so that they can be fastened with a high-strength bolt 23.

  Next, as shown in FIG. 6D, the connecting steel H-shaped steel 18 projecting from the footing unit 6-1 and the connecting steel H-shaped steel 18 projecting from the lower member are joined plates (not shown). ) And the high-strength bolt 23 to complete the framework of the base portion 25.

  After that, as shown in FIG. 6 (e), the footing unit 6-1 which is not provided with a wall surface in the footing unit 6-1 and the footing unit 6-1 connected by the H-shaped steel 18 of the connecting steel and the lower member of the joining unit 8 The primary concrete 24 is placed between the two and the foundation portion 27 in the dam body 1 of the present invention is completed.

  FIG. 7 shows processes from the completion of the foundation portion 25 to the completion of the dam body 1 of the present invention. (F-1) and (f-2) are steps of standing the double wall unit 14 (first wall panel 4-1) and the upper member (second wall panel 4-2) of the joining unit 8 in the footing 6. Indicates. (F-1) is a view from the front, and (f-2) is a view from the back. (G-1) and (g-2) show the placing process of the secondary concrete 26. (G-1) is a view from the front, and (g-2) is a view from the back. (H) shows a soil backfilling process (building process of the road 3).

  As shown in FIGS. 7 (f-1) and 7 (f-2), the steel pipe pile 5 in the footing unit 6-1 is connected to the connecting portion 10 of the double wall unit 14 including the first wall panel 4-1. The upper wall connecting portion 10 of the joining unit 8 having the second wall panel 4-2 is inserted into the hole 22 formed by the embedded inner mold 21 in the upper end pipe, and the double wall unit 14 and the joining unit are inserted. Eight upper members are erected to form a wall surface of the levee body 1 of the present invention comprising the first wall panel 4-1 and the second wall panel 4-2. Between the 1st wall panel 4-1 and the 2nd wall panel 4-2, as above-mentioned, the clearance gap is block | closed with the water stop material, and watertightness is ensured (illustration omitted).

  Next, as shown in FIGS. 7 (g-1) and 7 (g-2), the secondary concrete 26 is placed and covered with the footing unit 6-1 and filled into the pipe at the upper end of the steel pipe pile 5. The connection unit 10 (the connection column 9) is fixed, and the upper member of the joining unit 8 is fixed by filling the hole 22 formed by the embedded inner mold 21.

  Thereafter, as shown in FIG. 7 (h), backfilling with backfilling soil 27 is performed, and the dam body 1 of the present invention is completed. Moreover, the road 3 is constructed | assembled on the back side of the bank body 1 as needed.

  In the construction method of the bank body 1 shown in FIGS. 6 to 7 as described above, the H-section steel can be more utilized. And the strong bank body 1 can be constructed | assembled efficiently and effectively with the amount of concrete smaller than before.

  Next, the present invention according to the second invention that does not use a footing or a joining unit will be described based on the drawings of FIGS.

  FIG. 8 is a view showing an example of the structure of the bank body 1 of the present invention (second invention) using the foundation portion 28 by the steel shell unit 29. (A) is a front view, (b) is a side view, (c-1) is a plan view at position A, and (c-2) is a plan view at position B. FIG.

  A foundation portion 28 is provided on the pile heads of the steel pipe piles 5 arranged in a line at a predetermined interval, and the double wall unit 14 is erected on the foundation portion 28 so that the dam body 1 is formed by the double wall panel 4. A wall surface is formed. The interval between the steel pipe piles 5 arranged in a row is preferably about 250 to 450 cm.

  The double wall unit 14 is similar to the one shown in FIG. 3 described above, and the double wall panel 4 (corresponding to the above-mentioned double wall panel 4-1) made of two precast plates is connected to the connecting column 9 with a headed stud 15. The space between the plates is a hollow portion 12 (space).

  As in the case of the aforementioned footing, the upper end portion of the steel pipe pile 5 enters the foundation portion 28, the connecting portion 10 of the double wall unit 14 is inserted into the pipe at the upper end portion of the steel pipe pile 5, and the concrete 13 (filled concrete 20 The steel pipe pile 5, the foundation 28, and the double wall unit 14 are integrated. Between the adjacent double wall panels 4, 4, the gap is closed with a water blocking material to form the wall surface of the dam body 1.

  The foundation portion 28 is formed by arranging the steel shell units 29 in the arrangement direction of the steel pipe piles 5 (continuous direction of the dam body 1) and connecting the adjacent steel shell units 29 and 29 to each other. .

  The steel shell unit 29 is a hybrid type of steel / concrete structure in which a box frame formed by assembling steel plates in a box shape is covered with concrete 13 (see FIG. 8 (c-2)), and is manufactured at a factory. . By using such a hybrid type steel shell unit 29, it is possible to construct a high-quality and high-performance dam body 1 even in the case of a single-row steel pipe pile, as well as to improve construction efficiency and reduce the amount of concrete used. I can plan.

  A hollow portion 12 is provided in the base portion 28 (steel shell unit 29). By providing the hollow portion 12, the amount of concrete used can be reduced and the weight can be reduced.

  FIG. 9 is a diagram illustrating an example of the steel shell unit 29. (A) is the perspective view of the steel shell unit 29, (b) is the perspective view which installed the steel shell unit 29 in the upper end part (pile head) of the steel pipe pile 5. FIG.

  As shown in FIG. 9A, the steel shell unit 29 is formed by covering the periphery of a box frame 17 (steel shell) made of a steel plate with concrete 13, and the central portion is a hollow portion 12. ing. Moreover, there are two openings 30 into which the upper end (pile head) of the steel pipe pile 5 is inserted. Moreover, the recessed part 31 for forming the hollow part 12 is provided in the steel shell unit 29 outer surface of the continuous direction (arrangement direction of the steel pipe pile 5) of the bank body 1 where the steel shell units 29 and 29 are connected. ing. Such a unit with a lot of space makes it easy to transport it by truck.

  The steel shell unit 29 shown in FIG. 9 (a) is installed with the upper ends of the steel pipe piles 5 and 5 inserted into the two openings 30, 30 of the steel shell unit 29, respectively, as shown in FIG. 9 (b). Is done. A support fixing member is provided between the steel shell unit 29 and the steel pipe pile 5 so that the steel shell unit 29 does not fall and is installed at a predetermined position (not shown).

  Next, an example of the construction method of the bank body 1 of the present invention (second invention) using the foundation portion 28 by the steel shell unit 29 will be shown.

  FIG. 10 is a perspective view showing a construction example of the bank body 1 of the present invention (second invention) when the steel pipe piles 5 are arranged in a line. (A) shows the construction process of the steel pipe pile 5, (b) shows the installation process of the steel shell unit 29, (c) shows the installation process of the double wall unit 14, and (d-1) shows the filling concrete 20. The placement process (the completion process of the foundation part 28) is shown. (D-2) is the reference figure which showed the placement range of the filling concrete 20 in the foundation part 28 clearly.

  As in the case of the first invention of the present invention described above, pile construction by the steel pipe pile 5 is performed, and the steel pipe piles 5 are arranged in a row at intervals of about 250 to 450 cm. FIG. 10A shows only a pair corresponding to the steel shell unit 29.

  Next, each steel shell unit 29 set as described in FIG. 9B is installed in the continuous direction of the levee body 1 so that the adjacent recesses 31 are in contact with each other, and the foundation frame of the foundation portion 28 is installed. Is completed. In FIG. 10B, only the installation of one steel shell unit 29 is shown. The hollow portion 12 is formed by the concave portions 31 and 31 where the adjacent steel shell units 29 and 29 are in contact with each other.

  In this way, the base frame of the base portion 28 is formed using the steel shell unit 29, and it is necessary to connect the adjacent footings that are apart from each other without using the joining unit. Because there is no, construction efficiency is good.

  Next, as shown in FIG. 10 (c), a base frame in which a double wall unit 14 formed by supporting a double wall panel 4 made of two precast plates by a connecting column 9 is formed of a steel shell unit 29. Standing on top. As in the case of the footing 6 described above, the connecting portion 10 of the double wall unit 14 is inserted into the pipe at the upper end of the steel pipe pile 5 in the steel shell unit 29 and temporarily fixed.

  Next, as shown in FIG. 10 (d-1), the foundation portion 28 is constructed by placing the interstitial concrete 20 (in-place concrete) in the foundation frame formed by the steel shell unit 29, and the levee body 1 is completed. As shown in FIG. 10 (d-2), the placement range of the interstitial concrete 20 (in-situ concrete) is two openings 30 of the steel shell unit 29. As shown in FIG. 10 (d-1), the filling concrete 20 (in-situ concrete) is placed from the gap between the lower end of the double wall unit 14 and the opening 30 of the steel shell unit 29.

  As described above, even in the case of the embankment 1 construction by the one-row arrangement of the steel pipe piles 5 not using the footing (in the case of the second invention of the present invention), the double wall unit 14 is used instead of the footing unit 6-1. If the steel shell unit 29 is used, as in the case of the first invention of the present invention, the strong dam body 1 can be constructed efficiently and effectively with a smaller amount of concrete than before. Further, the double wall unit 14 and the steel shell unit 29 manufactured in the factory are hybrid and have a medium size having a hollow portion 12 (space, etc.), so that they have high performance and high quality and are easily transported by land.

  DESCRIPTION OF SYMBOLS 1 ... Bank body, 2 ... Existing levee, 3 ... Road, 4 ... Double wall panel, 4-1 ... 1st wall panel, 4-2 ... 2nd wall panel, 5 ... Steel pipe pile, 6 ... Footing, 6- DESCRIPTION OF SYMBOLS 1 ... Footing unit, 7 ... Connection steel material, 8 ... Joining unit, 9 ... Connection support | pillar, 10 ... Connection part, 11 ... Partition steel plate, 12 ... Hollow part, 13 ... Concrete, 14 ... Double wall unit, 15 ... Headed Stud, 16 ... Block, 17 ... Box frame, 18 ... H-shaped steel, 19 ... Ceiling steel plate, 20 ... Filled concrete, 21 ... Embedded formwork, 22 ... Hole, 23 ... High strength bolt, 24 ... Primary concrete , 25 ... foundation part, 26 ... secondary concrete, 27 ... backfilling soil, 28 ... foundation part (by steel shell unit), 29 ... steel shell unit, 30 ... opening, 31 ... recess

Claims (11)

  A dam body in which double wall units are arranged in the dam body continuous direction to form a wall surface, the steel pipe piles arranged in two rows, the footings supported by the steel pipe piles, and the two disposed above the footings The double wall unit is formed by connecting two precast plates arranged in parallel at a predetermined interval by a connecting column, and the double wall unit includes a connecting column. A dam body characterized in that a lower end portion is a connecting portion with the steel pipe pile.   The dam body according to claim 1, wherein the connecting column is made of H-shaped steel.   The levee body according to claim 1 or 2, wherein the footing uses a footing unit, and the footing unit is a box frame framed with a steel material.   The levee body according to any one of claims 1 to 3, wherein the footing is divided into three parts by a steel material, and a central part is a hollow part. The levee body according to claim 3, wherein the footing is obtained by covering the periphery of the footing unit in which two H-shaped steels are arranged to form a box frame with concrete.   The upper end portion of the steel pipe pile is inserted into the footing, the connection portion of the connecting column is inserted into the pipe at the upper end portion of the steel pipe pile, and the periphery of the steel pipe pile is solidified with concrete to form the double wall. The dam body according to any one of claims 1 to 5, wherein the unit, the footing, and the steel pipe pile are integrated.   A dam body in which wall surfaces are formed by arranging double wall units in a continuous direction of a dam body, comprising steel pipe piles arranged in a line, a steel shell unit, and a foundation part supported by the steel pipe piles. And a double wall unit disposed above the foundation, wherein the double wall unit is formed by connecting two precast plates arranged in parallel at a predetermined interval with connecting struts. An embankment characterized in that it is connected, and a lower end portion of the connecting column is a connecting portion with the steel pipe pile.   The upper end portion of the steel pipe pile has entered into the foundation portion, the connection portion of the connecting column is inserted into the pipe at the upper end portion of the steel pipe pile, and the periphery of the steel pipe pile is solidified with concrete, The dam body according to claim 7, wherein the double wall unit, the foundation portion, and the steel pipe pile are integrated.   The levee body according to claim 7 or 8, wherein the connecting strut is made of H-section steel.   The dam body according to any one of claims 7 to 9, wherein the foundation portion made of the steel shell unit and the filled concrete has a hollow portion.   The bank body according to any one of claims 1 to 10, wherein a space is provided between the two precast plates in the double wall unit.