Half-precast structure seawall and its construction method

Abstract

To provide a half-precast structure tide embankment which sufficiently absorbs a construction error generated during construction of a foundation pile in a construction site, and enables highly accurate construction.SOLUTION: A foundation part comprises: foundation piles that are partially driven into the ground and have upper ends projecting to a ground surface; leveling concrete for leveling a predetermined range of the ground surface surrounding the foundation piles; and a footing part that includes the upper ends of the foundation piles above the leveling concrete and is provided so as to support tide embankment panels. The foundation piles are constituted in two arrays that are parallel to each other. The tide embankment panels are pre-cast concrete members that are arranged in an intermediate position of the two arrays arrangement of the foundation piles on the leveling concrete. The footing part is composed of cast-in-place concrete including a reinforcement structure including a reinforcement group fastened to an upper ends of the foundation piles and protruding upward and a reinforcement group protruding from a lower lateral part of the tide embankment panels.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a half-precast seawall that is installed along a coastline to protect against tsunamis caused by earthquakes and high waves caused by typhoons, and to prevent seawater from flooding onto land. [Background technology]

[0002] In earthquake-prone countries, including Japan, minimizing damage from tsunamis caused by major earthquakes is an urgent issue. In recent years, typhoons have been getting stronger due to global warming, and damage from high waves caused by typhoons is becoming more serious. Seawalls installed along the coast against these natural disasters are expected to be a means of preventing coastal erosion and seawater inundation inland.

[0003] As examples of conventional seawalls, Patent Documents 1 and 2, for example, disclose technology for constructing a strong embankment without the need for skilled workers by using precast components (precast walls) to reduce the amount of cast-in-place concrete used in construction and thereby reduce the amount of concrete used at the construction site.

[0004] Furthermore, for example, Patent Document 3 discloses a technology for constructing a structure that uses precast components (precast dam body portion) to reduce the amount of on-site construction work and that can be applied to locations with poor ground conditions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-183453 A [Patent Document 2] JP 2015-196983 A [Patent Document 3] JP 2019-35259 A Summary of the Invention [Problem to be solved by the invention]

[0006] Japan's coastline is surrounded by ocean and is vast, and because construction is also dependent on the weather, the installation and maintenance of seawalls requires significant costs and time, creating a need for greater efficiency in construction.The use of components manufactured in advance in factories (precast components) is an effective way to increase construction efficiency and shorten construction times, but when using precast components, it is necessary to absorb construction errors that occur in the foundations (such as steel pipe piles and steel pipe sheet piles) constructed on site during construction of the precast components, and to build seawalls with specified dimensions and layout.

[0007] In this regard, the embankments described in Patent Documents 1 and 2 above are constructed using a foundation (steel-concrete composite footing) fabricated in a factory and a precast solid wall, and do not take any measures to absorb construction errors in the steel pipe piles installed at the actual construction site, which means there is a risk that construction errors at the construction site will not be sufficiently absorbed.

[0008] Furthermore, in the embankment described in Patent Document 3, the walls, footings, etc., except for the steel pipe piles, are all made of precast members, and there is no mention of construction errors between the steel pipe piles that are directly installed at the construction site and the precast members.

[0009] In view of the above circumstances, the object of the present invention is to provide a half-precast structure seawall that can be constructed with high precision by fully absorbing construction errors that occur when constructing foundation piles at the construction site when building a half-precast structure seawall. [Means for solving the problem]

[0010] In order to achieve the above object, according to the present invention, there is provided a half-precast seawall comprising a foundation and a number of seawall panels arranged on the foundation to form a wall, the foundation being comprised of foundation piles, parts of which are driven into the ground with their upper ends protruding above the ground surface, levelling concrete for levelling the ground surface within a prescribed range surrounding the foundation piles, and a footing above the levelling concrete, which contains the upper ends of the foundation piles and is arranged to support the seawall panels, the foundation piles being arranged in two rows parallel to each other, and the seawall panels being comprised of: It is a precast concrete member, The foundation piles are arranged at the center of the two rows of the foundation piles on the leveled concrete. The lower end of the support is supported by being sandwiched between the footing portion and is integrally formed. The footing portion is made up of a group of reinforcing bars fixed to the upper ends of the foundation piles and protruding upward, and a lower portion of the seawall panel. From the side A half-precast structure seawall is provided, characterized in that it is made of cast-in-place concrete containing a steel bar structure including a group of protruding steel bars. Effect of the Invention

[0011] According to the present invention, a half-precast structure seawall is provided that can be constructed with high precision by fully absorbing construction errors that occur when constructing foundation piles at the construction site when building a half-precast structure seawall. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic explanatory diagram of a half-precast seawall according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Diagram 3] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Figure 4] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Diagram 5]FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Figure 6] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Figure 7] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Figure 8] FIG. 1 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a first embodiment. [Figure 9] FIG. 11 is a schematic explanatory diagram of a half-precast seawall according to a second embodiment of the present invention. [Figure 10] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 11] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 12] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 13] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 14] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 15] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 16] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 17] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 18] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a second embodiment. [Figure 19] FIG. 11 is a schematic explanatory diagram of a half-precast seawall according to a third embodiment of the present invention. [Figure 20] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Figure 21] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Figure 22] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Diagram 23] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Figure 24] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Diagram 25] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Figure 26] FIG. 11 is a schematic explanatory diagram showing a method for constructing a half-precast structure seawall in accordance with a third embodiment. [Figure 27] FIG. 13 is a schematic explanatory diagram of a half-precast seawall according to a fourth embodiment of the present invention. [Figure 28] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Figure 29] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 30] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 31] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 32] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 33] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 34]FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. [Diagram 35] FIG. 13 is a schematic explanatory diagram showing a method for constructing a half-precast seawall in accordance with a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration may be given the same reference numerals to avoid repeated explanation. In other words, in the following specification, components common to each embodiment may be illustrated with the same reference numerals, and their explanation may be omitted. For the sake of explanation, the ground and the ground surface are not illustrated, and a steel pipe pile driven into the ground is illustrated.

[0014] <First embodiment> (Configuration of half-precast seawall 1a) Fig. 1 is a schematic explanatory diagram of a half-precast seawall 1a according to a first embodiment of the present invention. As shown in Fig. 1, the half-precast seawall 1a comprises a plurality of steel pipe piles 2 as a foundation installed along the coastline, leveling concrete 3, and a footing 5 provided above the leveling concrete 3. In addition, a plurality of seawall panels 10 are arranged above the footing 5. Note that the "coastline" here includes the river bank into which seawater enters.

[0015] To construct the foundation 20 of the half-precast seawall 1a, a number of steel pipes serving as foundation piles are driven into the ground, and are arranged in a substantially straight line (substantially in a row) at predetermined intervals (for example, equal intervals) as a number of steel pipe piles 2. There are no particular limitations on the method of driving the steel pipe piles 2 into the ground. The steel pipe piles 2 are installed with a portion of them driven into the ground and their upper ends protruding above the ground surface. Furthermore, leveling concrete 3 is provided around the steel pipe piles 2 to level the ground surface in a predetermined range surrounding the steel pipe piles 2. The leveling concrete 3 is applied to level out unevenness in the ground surface at the location where the half-precast seawall 1a is to be constructed.

[0016] A footing 5 made of cast-in-place concrete is provided above the leveling concrete 3. The shape and configuration of the footing 5 are arbitrary, but for example, as shown in the figure, it may be configured as a substantially rectangular parallelepiped with a predetermined height and a rectangular cross section. As will be described later, the footing 5 contains the upper end of the steel pipe pile 2 and a plurality of reinforcing bars (reinforcing bar group) as reinforcing bars, and a plurality of reinforcing bars protrude upward from the upper surface of the footing.

[0017] The foundation 20 of the half-precast seawall 1a is constructed by constructing the steel pipe piles 2, the leveling concrete 3, and the footing 5. All of these structures are constructed on-site.

[0018] In addition, a plurality of (four in FIG. 1) seawall panels 10, which are precast concrete members (hereinafter also referred to as precast members), are supported and arranged on the upper part of the footing part 5. The seawall panels 10 are preferably arranged directly above the steel pipe piles 2. The seawall panel 10 has a substantially rectangular parallelepiped shape, and is configured such that the thickness d1 of the lower part is thicker than the thickness d2 of the upper part. The thickness of the seawall panel 10 in the present invention is not particularly limited and may be uniform, for example. However, by making the thickness d1 of the lower part thicker than the thickness d2 of the upper part, the rigidity of the lower part of the seawall panel 10 can be increased, and the wave resistance can be improved. In addition, as described later, a plurality of reinforcing bars protruding upward from the footing part 5 are contained inside the seawall panel 10 via a connecting means such as a sleeve joint, and the footing part 5 and the seawall panel 10 are connected to each other.

[0019] The half-precast seawall 1a according to the first embodiment of the present invention is constructed as described above. In this half-precast seawall 1a, the steel pipe piles 2, leveling concrete 3, and footing 5 that constitute the foundation 20 are all constructed on-site. On the other hand, the seawall panel 10 uses precast members that have been manufactured in advance in a factory or the like, and is constructed so that only assembly is performed on-site. As a result, construction errors that may occur during on-site construction, such as when driving the steel pipe piles 2, can be absorbed when constructing the footing 5, and the half-precast seawall 1a can be constructed and built with high precision.

[0020] In addition, the use of precast materials for the seawall panel 10 improves the efficiency of construction and shortens the construction period. In particular, for tall materials such as the seawall panel 10, construction on-site requires the erection of scaffolding, which necessitates various processes such as assembling and dismantling the scaffolding, so there are great benefits to using precast materials for the seawall panel 10.

[0021] (Construction method of half-precast structure seawall 1a) The construction method of the half-precast seawall 1a according to this embodiment is as follows: Figures 2 to 8 referred to below are schematic explanatory diagrams showing the construction method of the half-precast seawall 1a according to the first embodiment, and the construction method will be explained below with reference to Figures 2 to 8.

[0022] (Foundation work) First, as shown in Fig. 2, in the foundation work for the coast where a half-precast seawall 1a is to be installed, a plurality of steel pipes are driven into the ground as foundation piles at predetermined positions (for example, positions along the coastline) to form a plurality of steel pipe piles 2 arranged in a substantially line at equal intervals in the ground. There is no particular restriction on the method of driving the steel pipe piles 2 into the ground at this time. Parts of the driven steel pipe piles 2 are left protruding above the ground surface.

[0023] (Pouring leveling concrete 3) Next, as shown in Fig. 3, leveling concrete 3 is poured in a predetermined area around the driven steel pipe piles 2 to smooth out unevenness in the ground surface. Note that even after the leveling concrete 3 is poured, the steel pipe piles 2 remain protruding upward from the surface of the leveling concrete 3.

[0024] (Construction of footing part 5) Next, as shown in FIG. 4, a group of reinforcing bars 22 is assembled on the upper surface of the leveling concrete 3 so as to surround the plurality of steel pipe piles 2. The group of reinforcing bars 22 is composed of a first group of reinforcing bars 22a arranged so as to cover the plurality of steel pipe piles 2 arranged in a substantially straight line, and a second group of reinforcing bars 22b arranged so as to protrude above the first group of reinforcing bars 22a. Then, in a state in which the group of reinforcing bars 22 is assembled, as shown in FIG. 5, a formwork 25 is assembled on the upper surface of the leveling concrete 3 so as to surround the four side surfaces of the group of reinforcing bars 22. Then, as shown in FIG. 6, a footing portion 5 is constructed by pouring concrete into the space surrounded by the formwork 25. As shown in the figure, the upper end of the second group of reinforcing bars 22b is left protruding from the upper surface of the footing portion 5 when the footing portion 5 is constructed.

[0025] The foundation 20 of the half-precast structure seawall 1a is composed of the steel pipe piles 2, the leveling concrete 3, and the footing 5 constructed as described above. All of the steel pipe piles 2, the leveling concrete 3, and the footing 5 are constructed on-site.

[0026] (Installation of seawall panel 10) Next, as shown in FIG. 7, the formwork 25 is removed, and a plurality of seawall panels 10 are arranged on the upper part of the footing 5 to form a wall. A plurality of reinforcing bar receiving parts (not shown), such as sleeve joints, are provided on the lower part of each seawall panel 10, and the reinforcing bar receiving parts are configured to receive the upper end of the second reinforcing bar group 22b protruding from the upper surface of the footing 5. With the upper end of the second reinforcing bar group 22b received in the reinforcing bar receiving parts, a time-hardening material such as mortar is filled inside, and the seawall panel 10 is installed and fixed at a predetermined position on the upper surface of the footing 5. In this way, the wall is finally formed as shown in FIG. 8, and the half-precast seawall 1a is constructed.

[0027] <Second embodiment> (Configuration of half-precast seawall 1b) Fig. 9 is a schematic explanatory diagram of a half-precast seawall 1b according to a second embodiment of the present invention. As shown in Fig. 9, the half-precast seawall 1b comprises a plurality of steel pipe piles 2 as a foundation installed along the coastline, leveling concrete 3, and a footing 5 provided above the leveling concrete 3. In addition, a plurality of seawall panels 10 are arranged so as to be integrated with the footing 5.

[0028] To construct the foundation 20 of the half-precast seawall 1b, a number of steel pipe piles 2, which serve as foundation piles, are driven parallel to one another in roughly two rows. The steel pipe piles 2 are installed with a portion of them driven into the ground and their upper ends protruding above the ground surface. Furthermore, leveling concrete 3 is provided around the steel pipe piles 2 to level the ground surface in a predetermined area surrounding the steel pipe piles 2.

[0029] A footing 5 made of cast-in-place concrete is provided above the leveling concrete 3. The footing 5 may have any shape and configuration, but may, for example, be configured as a substantially rectangular parallelepiped with a predetermined height and a rectangular cross section, and may be configured so as to be integrated with the lower end of a seawall panel 10 (described later) so as to sandwich it. The footing 5 contains the upper end of the steel pipe pile 2 and a plurality of reinforcing bars (reinforcing bar group) as reinforcing bars.

[0030] The foundation 20 of the half-precast seawall 1b is constructed by constructing the steel pipe piles 2, the leveling concrete 3, and the footing 5. All of these structures are constructed on-site.

[0031] In this embodiment, a plurality of (five in FIG. 9 ) seawall panels 10, which are precast members, are arranged in the middle of the two rows of steel pipe piles 2 that are driven in parallel in approximately two rows. These seawall panels 10 are supported by having their lower ends sandwiched between the footing portion 5, and are constructed as an integrated unit. As will be described later, the footing portion 5 contains a group of reinforcing bars (reinforcing bar group 30, described later) fixed to the upper ends of the steel pipe piles 2 and a plurality of reinforcing bars (reinforcing bar group 35, described later) protruding laterally from the lower part of the seawall panel 10, and the steel pipe piles 2, footing portion 5, and seawall panel 10 are connected together.

[0032] The half-precast seawall 1b according to the second embodiment of the present invention is constructed as described above. In this half-precast seawall 1b, the steel pipe piles 2, the leveling concrete 3, and the footing 5 constituting the foundation 20 are all constructed on-site. On the other hand, the seawall panel 10 is constructed using precast members fabricated in a factory or the like, and only assembly is performed on-site. This allows the construction error that may occur during on-site construction, such as when driving the steel pipe piles 2, to be absorbed when constructing the footing 5, and the half-precast seawall 1b can be constructed with high accuracy. Also, as in the first embodiment, the use of precast members as the seawall panel 10 improves the efficiency of construction and shortens the construction period.

[0033] (Construction method of half-precast structure seawall 1b) The construction method of the half-precast seawall 1b according to this embodiment is as follows: Figures 10 to 18, which will be referred to below, are schematic explanatory diagrams showing the construction method of the half-precast seawall 1b according to the second embodiment, and the construction method will be explained below with reference to Figures 10 to 18.

[0034] (Foundation work) First, as shown in Fig. 10, in the foundation work for the coast where a half-precast seawall 1b is to be installed, a plurality of steel pipe piles 2 as foundation piles are driven into the ground in predetermined positions (for example, positions along the coastline) so as to be parallel to each other and form approximately two rows. The method of driving the steel pipe piles 2 into the ground at this time is not particularly limited. Parts of the driven steel pipe piles 2 are left protruding above the ground surface.

[0035] (Pouring leveling concrete 3) Next, as shown in Fig. 11, leveling concrete 3 is poured in a predetermined area around the driven steel pipe piles 2 to smooth out unevenness in the ground surface. Even after the leveling concrete 3 is poured, the steel pipe piles 2 are left protruding upward from the surface of the leveling concrete 3.

[0036] (Installation of seawall panels 10 and construction of footings 5) Next, as shown in Fig. 12, a group of reinforcing bars 30 protruding upward is fixed to the upper end of the steel pipe pile 2. The group of reinforcing bars 30 is fixed by means of, for example, welding. The group of reinforcing bars 30 may be fixed on-site, or may be fixed to the end of the steel pipe pile 2 in advance. Then, as shown in Fig. 13, a plurality of (five in the figure) seawall panels 10 are arranged to form a wall at the midpoint of the two rows of steel pipe piles 2 arranged in approximately two parallel rows on the upper surface of the leveled concrete 3. Here, the seawall panel 10 is provided in advance with a group of reinforcing bars 35 protruding laterally from its lower portion, and is configured so that the group of reinforcing bars 30 and the group of reinforcing bars 35 do not interfere with each other when the seawall panels 10 are arranged.

[0037] 14 and 15, a reinforcing bar group 40 consisting of main reinforcing bars extending vertically to the surface of the seawall panel 10 and distribution bars extending so as to horizontally intersect with the main reinforcing bars is installed at a predetermined position on the upper surface of the leveled concrete 3. This reinforcing bar group 40 may be installed so as to connect to the reinforcing bar group 30. By installing each reinforcing bar group in this manner, as shown in FIG. 15, reinforcing bar group 30, reinforcing bar group 35, and reinforcing bar group 40 are integrally arranged on the upper surface of the leveled concrete 3, forming a reinforcing bar structure 42.

[0038] Next, as shown in Fig. 16, formwork 45 is assembled on top of the leveled concrete 3 so as to surround all four side surfaces of the reinforcing steel structure 42. Then, as shown in Fig. 17, concrete is poured in the space enclosed by the formwork 45 so as to bury the reinforcing steel structure 42, thereby constructing the footing 5. The formwork 45 is then removed, and finally, as shown in Fig. 18, the seawall panel 10 and the footing 5 are integrated to form a wall, and the half-precast seawall 1b is constructed. In this embodiment, a case has been illustrated and described in which a plurality of steel pipe piles 2 are driven into the ground in approximately two rows parallel to each other as foundation piles. However, instead of these steel pipe piles 2, the foundation piles may also be steel pipe sheet piles consisting of a plurality of steel pipe sheet piles arranged in close contact with each other.

[0039] <Third embodiment> (Configuration of half-precast seawall 1c) Fig. 19 is a schematic explanatory diagram of a half-precast seawall 1c according to a third embodiment of the present invention. As shown in Fig. 19, the half-precast seawall 1c comprises steel pipe sheet piles 2a as foundations installed along the coastline, leveling concrete 3, and a footing 5 provided above the leveling concrete 3. In addition, above the footing 5, a plurality of seawall panels 10 are arranged.

[0040] To construct the foundation 20 of the half-precast seawall 1c, a plurality of steel pipe sheet piles are driven into the ground as foundation piles, and are arranged in a substantially straight line as steel pipe sheet pile piles 2a. There is no particular limitation on the method of driving the steel pipe sheet pile piles 2a into the ground. The steel pipe sheet pile pile 2a is configured by arranging a plurality of steel pipe piles in close contact with each other continuously, and the shape and number of the steel pipe piles are optional. The steel pipe sheet pile pile 2a is installed with a portion driven into the ground and an upper end protruding above the ground surface. Moreover, around the steel pipe sheet pile pile 2a, leveling concrete 3 is provided to level the ground surface in a predetermined range surrounding the steel pipe sheet pile pile 2a.

[0041] A footing 5 made of cast-in-place concrete is provided above the leveling concrete 3. The shape and configuration of the footing 5 are arbitrary, but for example, as shown in the figure, it may be configured as a substantially rectangular parallelepiped with a predetermined height and a rectangular cross section. The foundation 20 of the half-precast seawall 1c is constructed by constructing the steel pipe sheet piles 2a, the leveling concrete 3, and the footing 5. All of these structures are constructed on-site.

[0042] Additionally, a plurality of (four in FIG. 19) seawall panels 10, which are precast members, are supported and arranged on the upper part of the footing portion 5. As in the above-described first embodiment, a plurality of reinforcing bars protruding upward from the footing portion 5 are contained inside the seawall panel 10 via connecting means such as sleeve joints, connecting the footing portion 5 and the seawall panel 10.

[0043] The half-precast seawall 1c according to the third embodiment of the present invention is constructed as described above. In this half-precast seawall 1c, the steel pipe sheet piles 2a, the leveling concrete 3, and the footing 5 constituting the foundation 20 are all constructed on-site. On the other hand, the seawall panel 10 is constructed using precast members fabricated in a factory or the like, and only assembly is performed on-site. This allows the construction error that may occur during on-site construction, such as when driving the steel pipe sheet piles 2a, to be absorbed when constructing the footing 5, and the half-precast seawall 1c can be constructed with high accuracy. Also, as in the first and second embodiments, the use of precast members as the seawall panel 10 improves the efficiency of construction and shortens the construction period.

[0044] (Construction method of half-precast structure seawall 1c) The construction method of the half-precast seawall 1c according to this embodiment is generally the same as that of the first embodiment. Figures 20 to 26 are schematic explanatory diagrams showing the construction method of the half-precast seawall 1c according to the third embodiment. As shown in Figures 20 to 26, the construction method of the half-precast seawall 1c according to this embodiment is the same as that of the first embodiment, except that steel pipe sheet piles 2a are used instead of the steel pipe piles 2, so a detailed description will be omitted.

[0045] <Fourth embodiment> (Composition of half-precast seawall 1d) Fig. 27 is a schematic explanatory diagram of a half-precast seawall 1d according to a fourth embodiment of the present invention. As shown in Fig. 27, the half-precast seawall 1d comprises steel pipe piles 2 as foundations installed along the coastline, leveling concrete 3, and a footing 5 provided above the leveling concrete 3. In addition, above the footing 5, a plurality of seawall panels 10 are arranged.

[0046] To construct the foundation 20 of the half-precast seawall 1d, a number of steel pipe piles 2, which serve as foundation piles, are driven parallel to one another in roughly two rows. The steel pipe piles 2 are installed with a portion of them driven into the ground and their upper ends protruding above the ground surface. Furthermore, leveling concrete 3 is provided around the steel pipe piles 2 to level the ground surface in a predetermined area surrounding the steel pipe piles 2.

[0047] A footing 5 made of cast-in-place concrete is provided above the leveling concrete 3. The shape and configuration of the footing 5 are arbitrary, but for example, as shown in the figure, it may be configured as a substantially rectangular parallelepiped with a predetermined height and a rectangular cross section. The foundation 20 of the half-precast seawall 1c is constructed by constructing the steel pipe sheet piles 2a, the leveling concrete 3, and the footing 5. All of these structures are constructed on-site.

[0048] Additionally, a plurality of (five in FIG. 27) seawall panels 10, which are precast members, are supported and arranged on the upper part of the footing portion 5. As in the above-described first and third embodiments, a plurality of reinforcing bars protruding upward from the footing portion 5 are contained inside the seawall panel 10 via connecting means such as sleeve joints, connecting the footing portion 5 and the seawall panel 10.

[0049] The half-precast seawall 1d according to the fourth embodiment of the present invention is constructed as described above. In this half-precast seawall 1d, the steel pipe piles 2, the leveling concrete 3, and the footing 5 constituting the foundation 20 are all constructed on-site. On the other hand, the seawall panel 10 is constructed using precast members fabricated in a factory or the like, and only assembly is performed on-site. This allows the construction error that may occur during on-site construction, such as when driving the steel pipe piles 2, to be absorbed when constructing the footing 5, and the half-precast seawall 1d can be constructed with high accuracy. Also, as in the first to third embodiments, the use of precast members as the seawall panel 10 improves the efficiency of construction and shortens the construction period.

[0050] (Construction method of half-precast seawall 1d) The construction method of the half-precast structure seawall 1d according to this embodiment is generally the same as that of the first embodiment. Figures 28 to 35 are schematic explanatory diagrams showing the construction method of the half-precast structure seawall 1d according to the fourth embodiment. As shown in Figures 28 to 35, the construction method of the half-precast structure seawall 1d according to this embodiment is the same as that of the first embodiment, except that the steel pipe piles 2 are arranged in approximately two rows parallel to each other, so a detailed description will be omitted. In this embodiment, a case has been illustrated and described in which a plurality of steel pipe piles 2 are driven parallel to each other in approximately two rows as foundation piles, but instead of these steel pipe piles 2, steel pipe sheet piles in which steel pipe sheet piles are driven into the ground may also be used as foundation piles.

[0051] (Action and effect) According to the half-precast structure seawalls 1a-1d configured as described above, when constructing a seawall with a half-precast structure, construction errors in the foundation piles (steel pipe piles 2 and steel pipe sheet piles 2a) at the construction site can be fully absorbed when constructing the footing 5 and when arranging the seawall panels 10. This enables high-precision construction when constructing the half-precast structure seawalls 1a-1d.

[0052] In constructing the half-precast structure seawalls 1a-1d, the foundation piles (steel pipe piles 2, steel pipe sheet piles 2a), leveling concrete 3, and footing 5 that make up the foundation 20 are constructed on-site. Meanwhile, the seawall panel 10 uses precast members that have been manufactured in advance in a factory or the like, and is configured so that only assembly is performed on-site. In other words, by combining on-site construction such as cast-in-place concrete with precast members, it is possible to improve the efficiency of construction work and shorten the construction period.

[0053] Although an example of an embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0054] In the above embodiment, the case where the foundation portion 20 is formed using the steel pipe piles 2 or the steel pipe sheet piles 2a as the foundation piles has been illustrated and described, but the present invention is not limited to this. For example, the foundation piles may be steel sheet piles or hat-shaped steel sheet piles. [Industrial Applicability]

[0055] The present invention can be applied to half-precast seawalls that are installed along coastlines and serve as revetments against tsunamis caused by earthquakes and high waves caused by typhoons, and to prevent seawater from flooding onto land. [Explanation of symbols]

[0056] 1 (1a~1d)…Half-precast seawall 2…Steel pipe pile 2a…Steel pipe sheet pile 3…Leveled concrete 5…Footing section 10… Seawall panel 20...Foundation part 22...Reinforcing bars 25…Formwork 30...Reinforcing bars (at the top of steel pipe piles) 35...Reinforcing bars (on the lower side of the seawall panel) 40...Reinforcing bar group (consisting of main reinforcing bars and distribution bars) 42…Reinforced concrete structure 45…Formwork

Claims

1. A half-precast seawall structure comprising a foundation and a plurality of seawall panels arranged on the foundation to form a wall, The foundation portion is a foundation pile that is installed with a part of the foundation pile driven into the ground and an upper end of the foundation pile protruding above the ground surface; A leveling concrete for leveling the ground surface of a predetermined range surrounding the foundation pile; a footing portion provided above the leveling concrete to contain the upper end of the foundation pile and to support the seawall panel; The foundation piles are arranged in two rows parallel to each other, The seawall panel is a precast concrete member, and is arranged at the center of the two rows of the foundation piles on the leveled concrete, and its lower end is supported so as to be sandwiched between the footing portion and is integrally formed, This is a half-precast seawall structure, characterized in that the footing portion is made of cast-in-place concrete containing a reinforced concrete structure including a group of reinforcement bars fixed to the upper ends of the foundation piles and protruding upward, and a group of reinforcement bars protruding laterally from the lower part of the seawall panel.

2. The half-precast structure seawall described in claim 1, characterized in that the foundation piles are steel pipe piles consisting of two rows parallel to each other and in which a plurality of steel pipes are driven into the ground, or steel pipe sheet pile piles consisting of a plurality of steel pipe sheet piles driven into the ground in continuous, close contact with each other.

3. A half-precast structural seawall as described in claim 1 or 2, characterized in that in the footing portion, a group of reinforcing bars consisting of main reinforcing bars extending vertically to the surface of the seawall panel and distribution bars extending so as to intersect with the main reinforcing bars is embedded so as to connect to the group of reinforcing bars fixed to the upper ends of the foundation piles and protruding upward.

4. A method for constructing a half-precast structure seawall comprising a foundation and a plurality of seawall panels arranged on the foundation to form a wall, comprising: A plurality of foundation piles are provided in two rows parallel to each other in the extension direction of the half-precast seawall, with a portion of each pile driven into the ground and an upper end portion protruding above the ground surface. Pour leveling concrete over a predetermined area of ​​the ground surface surrounding the two rows of foundation piles; Above the leveling concrete, the plurality of seawall panels are arranged at the center of the two rows of the foundation piles with reinforcing bars protruding laterally from the lower part of the panels; A method for constructing a half-precast structure seawall as described in claim 3, characterized in that after arranging the main reinforcing bars, the distribution bars, and the reinforcing bars fixed to the upper ends of the foundation piles, all of the reinforcing bars are buried inside, and in-situ concrete is poured to sandwich and support the lower ends of the seawall panels and integrate them, thereby completing the footing.

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