JP7364526B2 - Quay wall structure and construction method of quay wall structure - Google Patents

Description

The present invention relates to a quay structure and a method of constructing a quay structure.

In a quay structure, a steel retaining wall built deeper than the seabed resists back earth pressure. Steel sheet piles and steel pipe sheet piles are generally used as steel materials for earth retaining walls because they can be easily driven into the ground. When the water depth becomes large, steel sheet piles or steel pipe sheet piles alone do not have enough resistance to the back earth pressure, so a tie rod structure installed at the back or a pier structure installed at the front reduces the horizontal force at the head of the wall. It has a structure that supports it and resists back earth pressure. When adding a pier in front of the normal line of the seawall, a jacket structure is used for the front pier as an economical and rapid construction method, but the retaining walls are directly connected with the jacket. Instead, the rear earth pressure acting on the earth retaining wall is transmitted only horizontally to the jacket structure constructed on the sea side. Therefore, steel is required for both the retaining wall and the pier, and as a result of the increased amount of steel, the economic efficiency tends to decline.

On the other hand, Patent Document 1 proposes a technique in which a sheet-like member, for example, a straight steel sheet pile, is used to construct an arch-shaped earth retaining wall that is convex toward the sea. In this case, the back earth pressure is transmitted to the legs of the jacket structure as horizontal tension in the retaining wall. By utilizing the tension rather than the bending rigidity of the earth retaining wall, we constructed a steel sheet pile wall that can resist rear earth pressure while suppressing the increase in the amount of steel material due to an increase in cross section or the addition of side elevation work. can do. Further, Patent Document 2 proposes a steel wall configured by combining a hat-shaped steel sheet pile and a steel pipe. Patent Document 3 proposes a technique for reinforcing a steel sheet pile wall with a steel pipe or an H-beam.

Japanese Patent Application Publication No. 2005-194867 International Publication No. 2011/142367 International Publication No. 2013/164885

However, in the case of a steel sheet pile wall as described in Patent Document 1, only the support structure including the jacket structure resists the rear earth pressure transmitted by tension from the earth retaining wall, and the load borne by the support structure is reduced. As a result, the amount of steel in the support structure increases, which is not economical, and also increases the difficulty of construction. The techniques of Patent Document 2 and Patent Document 3 make it possible to construct a steel wall with improved rigidity while suppressing an increase in the amount of steel material, but if the resistance against back earth pressure is insufficient, support such as a jacket structure There is no description of how to install the structure. Therefore, even when planning deepening work or seismic reinforcement of an existing seawall, it is necessary to construct a new wall structure and pier structure such as a jacket on the sea side of the existing wall, and to reduce the back earth pressure with only the new structure. It was designed to resist.

Therefore, the present invention provides a quay wall structure and a method for constructing a quay wall structure that can utilize existing walls to suppress an increase in the amount of steel, improve the rigidity of the wall, and reduce the load borne by the support structure. The purpose is to provide

[1] A plurality of steel pipe piles connected to a steel sheet pile wall at a portion above the underground portion, and a portion arranged at one ratio to the plurality of steel pipe piles and connected to the steel sheet pile wall at a portion above the underground portion. A first row of steel pipes arranged on the sea side of the steel sheet pile wall at intervals matching the unevenness of the planar shape of the steel sheet pile wall, and at least a part of the support pile structure. A quay wall structure comprising: a second steel pipe row in which at least one steel pipe sheet pile including a second steel pipe sheet pile functioning as a steel pipe sheet pile is arranged from the first steel pipe sheet pile in a direction crossing the extension direction of the steel sheet pile wall.
[2] The quay wall structure according to [1], further comprising a backing pile structure located on the sea side than the supporting pile structure, and a connecting member connecting the supporting pile structure to the backing pile structure.
[3] The support pile structure includes a second steel pipe sheet pile and a first jacket leg that fits on the outside of the head of the second steel pipe sheet pile, and the support pile structure includes a support pile and a support pile. a second jacket leg that fits on the outside of the head of the pile; the connecting member includes a first connecting member disposed between the first jacket leg and the second jacket leg; 2] quay wall structure described in [2].
[4] The support pile structure includes a fitting member that fits inside the head of the first steel pipe sheet pile, and the connecting member includes a first jacket leg and a fitting member that is disposed between the first jacket leg and the fitting member. The quay wall structure according to [3], including the second connecting member.
[5] At the head of the second steel pipe sheet pile, no joint is formed between the adjacent steel pipe sheet pile, and the first jacket leg fits into the portion where the joint is not formed from the outside, [3] or The quay structure described in [4].
[6] In a joint space surrounded by fitting a joint between the first steel pipe sheet pile and the steel pipe sheet pile included in the second steel pipe row, or between the steel pipe sheet piles included in the second steel pipe row. The quay structure according to any one of [1] to [5], wherein the anti-slip protrudes from the peripheral surface of the steel pipe sheet pile, and the joint space is filled with a filler.
[7] On the sea side of the steel sheet pile wall, a plurality of steel pipe piles and a first steel pipe sheet pile, one for each of the plurality of steel pipe piles, are arranged at intervals that match the unevenness of the planar shape of the steel sheet pile wall. a step of constructing a first steel pipe row and connecting the steel sheet pile wall and the first steel pipe row at a portion above the underground portion; and a step of connecting at least one steel pipe sheet pile to the first steel pipe sheet pile. A method for constructing a quay wall structure, the method comprising the steps of: constructing a second steel pipe row with a second steel pipe row; and incorporating a second steel pipe sheet pile included in the second steel pipe row into a support pile structure.
[8] The step of assembling the second steel pipe sheet pile into the support pile structure includes the step of fitting the first jacket leg to the outside of the head of the second steel pipe sheet pile, and attaching the connecting member to the first jacket leg. The method for constructing a quay wall structure according to [7], further comprising the step of driving a retaining pile on the seaward side of the first steel pipe sheet pile using the second jacket leg connected via the second jacket leg as a guide.
[9] Installing a first jacket leg, a second jacket leg located on the seaward side of the first jacket leg, and a connecting member connecting the first jacket leg to the second jacket leg; The step of incorporating the second steel pipe sheet pile into the support pile structure includes driving the first steel pipe sheet pile using the first jacket leg as a guide. The method for constructing a quay structure according to [7], including the step of:

According to the above configuration, the steel sheet pile wall has a bending resistance force against back earth pressure, the first row of steel pipes is arranged in the extension direction of the steel sheet pile wall, and the first row of steel pipes is arranged in the direction crossing the steel sheet pile wall. Since the second row of steel pipes behaves integrally as a wall, it is possible to easily construct a quay wall structure having desired bending rigidity against back earth pressure. Further, the rotational moment generated in the earth retaining wall due to rear earth pressure can be resisted by the vertical ground reaction force applied to the second steel pipe row. Therefore, the load borne by the support structure can be reduced while suppressing an increase in the amount of steel material.

FIG. 1 is a plan view of a quay structure according to an embodiment of the present invention. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a diagram showing a modification of the example shown in FIG. 2. FIG. 2 is a diagram showing an example of a joint that can be used in the quay structure shown in FIG. 1. FIG. It is a graph showing the relationship between cross-sectional performance and material cost when steel pipes are arranged discretely, compared with when they are arranged continuously (steel pipe sheet pile wall). It is a graph showing the results of calculating the displacement with respect to the total load by the finite element method (FEM) between the example of the present invention and the comparative example. It is a graph showing the results of calculating the load sharing ratio of the wall by frame calculation when the number of steel pipe sheet piles constituting the steel pipe rows arranged in the direction intersecting the wall is changed in an example of the present invention. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.

FIG. 1 is a plan view of a quay structure according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. 1. As illustrated, the quay structure 1 includes a steel sheet pile wall 2, a first steel pipe row 3 arranged on the sea side of the steel sheet pile wall 2, and a steel pipe sheet pile 31 (first steel pipe sheet pile 31) included in the first steel pipe row 3. The second steel pipe row 4 is arranged toward the sea side from the steel pipe sheet pile 1), that is, in the direction intersecting the extension direction of the steel sheet pile wall 2, and the steel sheet pile wall 2 of the second steel pipe row 4 is opposite. The support pile structure 5 includes a steel pipe sheet pile 41 (second steel pipe sheet pile) located at the side end and a jacket leg 52 that fits on the outside of the head of the steel pipe sheet pile 41.

Here, in this specification, a steel pipe row is constituted by one or more steel pipe piles or steel pipe sheet piles. A steel pipe sheet pile has at least one joint extending in the longitudinal direction of the steel pipe arranged on the circumferential surface of the steel pipe pile, and adjacently arranged steel pipe sheet piles are connected to each other by engaging the joint.

The first steel pipe row 3 includes a plurality of steel pipe piles 32 and a steel pipe sheet pile 31 (first steel pipe sheet pile), and the steel pipe sheet pile 31 is arranged at a ratio of one to the plurality of steel pipe piles 32. The plurality of steel pipe piles 32 and steel pipe sheet piles 31 are arranged at intervals that match the unevenness of the planar shape of the steel sheet pile wall 2, and are connected to the steel sheet pile wall 2 using a connecting member 33 at a portion above the underground part. . In the illustrated example, the plurality of steel pipe piles 32 are not connected to each other, and the plurality of steel pipe piles 32 and the steel pipe sheet piles 31 are not connected to each other. The joint 311 of the steel pipe sheet pile 31 is used for connection with the steel pipe sheet pile of the second steel pipe row 4.

The second steel pipe row 4 includes at least one steel pipe sheet pile including a steel pipe sheet pile 41 (second steel pipe sheet pile). In the illustrated example, two steel pipe sheet piles 42 and 43 are included in addition to the steel pipe sheet pile 41, and the second steel pipe row 4 is constituted by the three steel pipe sheet piles 41, 42, and 43. The steel pipe sheet pile 43 closest to the first steel pipe row 3 is connected to the steel pipe sheet pile 31 by engaging the joint 431 with the joint 311 of the steel pipe sheet pile 31 included in the first steel pipe row 3. Similarly, the steel pipe sheet pile 42 is connected to the steel pipe sheet pile 43, and the steel pipe sheet pile 41 is connected to the steel pipe sheet pile 42, respectively. In this way, the second steel pipe row 4 is arranged in a direction intersecting the extension direction of the steel sheet pile wall 2 from the steel pipe sheet pile 31 (first steel pipe sheet pile).

In addition, in other examples, the number of steel pipe sheet piles that constitute the second steel pipe row 4 may be smaller than the illustrated example. For example, a steel pipe sheet pile row is constructed by directly connecting the steel pipe sheet pile 31 (first steel pipe sheet pile) and the steel pipe sheet pile 41 (second steel pipe sheet pile) that functions as a part of the support pile structure. , intermediate steel pipe sheet piles may not be included. Alternatively, the number of steel pipe sheet piles constituting the second steel pipe row 4 may be greater than the illustrated example.

In this embodiment, the steel pipe sheet pile 41 (second steel pipe sheet pile) located at the end of the second steel pipe row 4 opposite to the steel sheet pile wall 2 is a part of the support pile structure 5 together with the jacket leg 52. (Support pile 51). In the illustrated example, the quay wall structure 1 includes a retaining pile structure 6 located on the sea side than the supporting pile structure 5, and a beam 7 that is a connecting member that connects the supporting pile structure 5 to the retaining pile structure 6. further including. The buck pile structure 6 includes a buck pile 61 and a jacket leg 62 that fits on the outside of the head of the buck pile 61, and the beam 7 is arranged between the jacket legs 52, 62.

FIG. 3 is a diagram showing a modification of the example shown in FIG. 2. In the example shown in FIG. 3, the support pile structure 5 further includes a fitting member 53 (also called stubbing) that fits inside the head of the steel pipe sheet pile 31 (first steel pipe sheet pile), and 7 includes a portion disposed between the jacket legs 52 and 62 (first connection member) and a portion disposed between the jacket leg 52 and the fitting member 53 (second connection member). .

Here, as shown in FIG. 2, in the support pile structure 5, the jacket leg 52 fits into the head of the steel pipe sheet pile 41 (support pile 51). The steel pipe sheet pile 41 is connected to an adjacent steel pipe sheet pile, for example, by a joint as described below, but at the head of the steel pipe sheet pile 41 where the jacket leg 52 fits on the outside, a joint is formed between the steel pipe sheet pile 41 and the adjacent steel pipe sheet pile. You don't have to. The construction of the jacket leg 52 is facilitated by leaving a gap between the steel pipe sheet pile 41 and the adjacent steel pipe sheet pile and fitting the jacket leg 52 from the outside into the portion where the joint is not formed.

FIG. 4 is a diagram showing an example of a joint that can be used in the quay wall structure shown in FIG. 1. In the illustrated example, a joint 401 between two steel pipe sheet piles 40 includes a pair of female joint members 401A protruding from the circumferential surface of one steel pipe sheet pile, and a pair of female joint members 401A protruding from the circumferential surface of the other steel pipe sheet pile. male side joint member 401B. The joint space surrounded by fitting the joints 401 between the steel pipe sheet piles, that is, the space surrounded by the female joint member 401A, the male joint member 401B, and the peripheral surfaces of the respective steel pipe sheet piles 40, is filled with a filler 402. be done. Specifically, the female joint member 401A and the male joint member 401B are formed of angle iron, for example. The filler 402 can be mortar, cement, concrete, or the like. Such a joint allows horizontal compressive loads and shear loads to be transmitted between the steel pipe sheet piles.

Furthermore, in this embodiment, the joint 401 has slippage stops 403A and 403B. The anti-slip members 403A and 403B protrude from the circumferential surface of the steel pipe sheet pile into the joint space between the pair of female joint members 401A or between the pair of male joint members 401B and are fixed to the filler 402. This ensures that the vertical shear load is transmitted between the steel pipe sheet piles more reliably. By arranging the anti-slips 403A and 403B, it is possible to more reliably prevent misalignment between the two steel pipe sheet piles 40 due to shearing in the vertical direction, and to secure the first steel pipe row 3 and the second steel pipe row 4. It can be made to behave as an integral wall. Note that the anti-slip members 403A and 403B may be, for example, ribs extending in the horizontal direction as shown in the figure, or may be beads that protrude in a dotted manner.

The above-described joint 401 can be used not only between the steel pipe sheet piles constituting the second steel pipe row 4, but also between the steel pipe sheet piles 31 of the first steel pipe row 3 and the steel pipe sheet piles of the second steel pipe row 4. may be placed. In addition, although not shown, the heads of the steel pipe piles and steel pipe sheet piles constituting the first steel pipe row 3 and the steel pipe sheet piles constituting the second steel pipe row 4 are fixed by coping, thereby forming a wall. The integrity of W may be increased.

Next, an example of a method for constructing a quay wall structure according to the present embodiment will be schematically described. First, on the sea side of the steel sheet pile wall 2, a plurality of steel pipe piles 32 and steel pipe sheet piles 31 (first steel pipe sheet piles) are arranged at intervals matching the unevenness of the planar shape of the steel sheet pile wall 2, and the first steel pipe Build column 3. Next, at least one steel pipe sheet pile is connected to the steel pipe sheet pile 31 included in the first steel pipe row 3 to construct the second steel pipe row 4. In the example shown in FIG. 1, the second steel pipe row 4 is constructed by sequentially connecting the steel pipe sheet pile 43, the steel pipe sheet pile 42, and the steel pipe sheet pile 41 to the steel pipe sheet pile 31. For example, the steel pipe sheet piles of the second steel pipe row 4 may be driven after all the steel pipe piles 32 and steel pipe sheet piles 31 of the first steel pipe row 3 are driven, or the steel pipe sheet piles of the second steel pipe row 4 may be driven after the steel pipe sheet piles 31 of the first steel pipe row 3 are driven. The steel pipe sheet piles of the second steel pipe row 4 may be driven in parallel with or before and after the driving of the steel pipe sheet piles 32 and other steel pipe sheet piles 31. Further, the steel pipe sheet piles of the second steel pipe row 4 do not necessarily have to be driven sequentially from the side closest to the first steel pipe row 3. For example, the steel pipe sheet piles 41 (second The steel pipe sheet piles) are driven first, and the other steel pipe sheet piles of the second steel pipe row 4 are driven so as to connect the steel pipe sheet piles 41 and the steel pipe sheet piles 31 (first steel pipe sheet piles) of the first steel pipe row 3. Pouring may be performed while adjusting the position.

After driving the steel pipe sheet pile 41 (support pile 51), a jacket structure including the jacket leg 52, the beam 7, and the jacket leg 62 is installed on the steel pipe sheet pile 41, and the retaining pile 61 is driven using the jacket leg 62 as a guide. As another example, the jacket structure (jacket leg 52, beam 7, and jacket leg 62) is installed in advance using temporary piles, and the steel pipe sheet piles 41 and retaining piles 61 are installed using the jacket legs 52 and 62 as guides. They may be placed separately. Through any of the above steps, the steel pipe sheet pile 41 located at the end of the second steel pipe row 4 opposite to the steel sheet pile wall 2 is incorporated into the support pile structure 5 as the support pile 51. A superstructure (not shown) constituting an apron portion of the quay may be installed above the jacket structure. The above process may be carried out as reinforcement work for the existing steel sheet pile wall 2, and a quay structure including the first steel pipe row 3 and the second steel pipe row 4 in addition to the steel sheet pile wall 2 may be constructed, A step of constructing the steel sheet pile wall 2 may be performed before the above steps.

When driving steel pipe piles and steel pipe sheet piles in port structures such as quays and piers, the vibratory hammer method is often used. The vibrohammer method is a construction method in which steel is driven into the ground by applying vibrations. In the vibrohammer construction method, in order to prevent damage to the steel pipe during construction, it is necessary to ensure a certain level of plate thickness relative to the steel pipe diameter. For example, the Vibro Hammer Construction Technology Research Group stipulates standard values for the ratio of plate thickness t to steel pipe diameter D: t/D≧1.0% or more for steel pipe piles, and t/D≧1.4% or more for steel pipe sheet piles. ing. Note that the standard value for steel pipe sheet piles is higher because the joints may cause resistance during driving.

On the other hand, cross-sectional properties such as moment of inertia and section modulus of a wall body including a steel pipe can be effectively improved by increasing the diameter of the steel pipe rather than by increasing the plate thickness. When constructing a wall by connecting steel pipe sheet piles with joints, there is a restriction that the steel pipe sheet piles are arranged consecutively through the joints in the direction of extension of the wall. It is necessary to increase the plate thickness relative to the diameter. On the other hand, unlike this embodiment, the steel pipes arranged in the extension direction of the wall are not connected, and the first steel pipe row is connected to the steel pipes except for the steel pipe sheet pile 31 connected to the second steel pipe row. When constructed with piles 32, even if the diameter of the steel pipe pile is increased, the plate thickness can be made smaller than that of a steel pipe sheet pile of the same diameter, and the steel pipe piles do not have to be arranged consecutively, so the amount of steel material can be reduced. The cross-sectional performance can be efficiently improved.

In this embodiment, the steel sheet piles 31 and the steel pipe piles are placed at intervals that match the irregularities of the planar shape of the steel sheet pile wall 2, based on the idea that the steel sheet pile wall has an earth retaining function and the steel pipe piles have the necessary strength. 32 are arranged to constitute the first steel pipe row 3. For example, in the case of a U-shaped steel sheet pile with a width of 400 mm, the pitch of the unevenness is 800 mm, so if the steel pipe sheet piles 31 and the steel pipe piles 32 with a diameter of 1200 mm are arranged at a pitch of 1600 mm, the result will be as shown in FIG. 1. In the example of FIG. 1, the steel sheet piles 31 and the steel pipe piles 32 are arranged at positions corresponding to the recesses in the planar shape of the steel sheet pile wall 2, and the web portions of the steel sheet piles located in the convexities in the planar shape and the connecting members 33 , specifically connected by steel plates. By setting the diameter of the steel pipe sheet pile 31 and the steel pipe pile 32 to 800 mm or more, which is more than twice the width of the U-shaped steel sheet pile 400 mm, the above arrangement becomes possible.

FIG. 5 is a graph showing the relationship between cross-sectional performance and material cost when steel pipes are arranged discretely, compared to when they are arranged continuously (steel pipe sheet pile wall). The graph in Figure 5 shows the cross-sectional moment of inertia per unit width when steel pipes are arranged at a pitch of 1600 mm on a steel sheet pile wall made of 400 mm wide U-shaped steel sheet piles as in the example above, and when the steel pipes are arranged at a pitch of 1600 mm on a steel sheet pile wall made of 400 mm wide U-shaped steel sheet piles, as in the example above. The relationship between this and the material cost per meter of length is shown. For each example, the moment of inertia of area was calculated considering only the rigidity of the steel pipe. In addition, material costs were calculated based on the dimensions of each member and construction prices. The joints for the steel pipe sheet piles were of the PP type specified in JIS A5530. In addition, for each example, multiple steel pipe diameters are set, and the plate thickness is t/D≧1.0% for steel pipe piles, and t/D≧1.4% for steel pipe sheet piles, assuming that they will be constructed using the vibrohammer construction method. The minimum value that satisfies

For example, in the case of a steel pipe sheet pile wall using steel pipes with a diameter of 1000 mm and a thickness of 14 mm (pitch of steel pipes is steel pipe diameter + joint length), the moment of inertia per unit width is 4.22 × 10 ⁵ (cm ⁴ ) become. On the other hand, if the steel pipes are arranged discretely as in this embodiment, in order to construct a wall with the same moment of inertia, steel pipes with a diameter of 1200 mm and a plate thickness of 12 mm must be arranged at a pitch of 1600 mm. Bye. As a result, the material cost can be reduced by about 40% compared to steel pipe sheet piles with the same moment of inertia. This is the same for other steel pipe diameters, and as mentioned above, for example, by using an existing steel sheet pile wall and arranging the steel pipes discretely, a predetermined cross section can be achieved with less material cost compared to a steel pipe sheet pile wall. It is possible to construct a wall that satisfies the performance requirements.

In addition, in this embodiment, the first steel pipe row 3 is arranged on the sea side of the steel sheet pile wall 2 that receives rear earth pressure from the ground G, and furthermore, the first steel pipe row 3 is arranged on the sea side from the steel pipe sheet pile 31 of the first steel pipe row 3. By arranging the second steel pipe row 4 toward the ground, the steel sheet pile wall 2, the first steel pipe row 3, and the second steel pipe row 4 are connected to the ground G with a U-shaped wall W (shown surrounded by chain lines). ) can be made to behave integrally. The cross-sectional moment of inertia of the wall W is larger than, for example, when only the first steel pipe row 3 parallel to the steel sheet pile wall 2 is constructed, and the second steel pipe row 4 is easily Therefore, it is possible to easily construct a quay wall structure 1 having a desired bending rigidity against back earth pressure. Further, the rotational moment generated in the steel sheet pile wall 2 due to rear earth pressure can be resisted by the vertical ground reaction force that the second steel pipe row 4 receives. Therefore, the load borne by the support structure can be reduced while suppressing an increase in the amount of steel material.

Furthermore, in this embodiment, since the steel pipe sheet piles of the second steel pipe row 4 do not constitute earth retaining walls, the spaces between the steel pipe sheet piles that constitute the second steel pipe row 4 and between the steel pipe sheet piles of the second steel pipe row 4 It is not necessarily necessary to connect the first steel pipe row 3 to the steel pipe sheet pile 31 over the entire length in the depth direction using a joint. Therefore, as described above, no joint is formed in the upper part between the steel pipe sheet pile 41 located at the end of the second steel pipe row 4 and the adjacent steel pipe sheet pile, and a gap is left around the steel pipe sheet pile 41. By keeping the jacket leg 52 in place, construction of the jacket leg 52 can be facilitated.

One embodiment of the present invention as described above can be applied when planning deepening work or seismic reinforcement for an existing seawall. Conventionally, such cases have been dealt with by constructing a new wall structure on the sea side of the existing wall and filling in the space between the existing wall and the new wall. In order to consider the increase in earth pressure due to deepening and earthquake load as external forces, the new wall needs to have higher bending rigidity than the existing wall. As a result, it is necessary to enlarge the cross section of the steel materials that make up the wall structure, which increases costs. Furthermore, since reclamation work was required, the total construction cost tended to be high.

On the other hand, when this embodiment is applied to deepening work or seismic reinforcement of a steel sheet pile wall constructed as an existing revetment, steel pipes are installed at positions adjacent to the existing wall in a discrete manner along the extension direction of the wall. The lack of rigidity is compensated for by arranging piles and steel pipe sheet piles. It is possible to construct a steel pipe sheet pile wall as a wall structure with high bending rigidity, but in the case of a steel pipe sheet pile wall, it is required to function as a wall by itself, so the steel pipe sheet piles are arranged continuously rather than discretely. There is a need. In the case of this embodiment, the existing steel sheet pile wall already exists as a surface that receives earth pressure, and it is sufficient to arrange steel pipe piles and steel pipe sheet piles to compensate for the insufficient rigidity, so that the bending rigidity can be compensated for rationally. Furthermore, since the process of constructing a new wall on the sea side is omitted, there is no need for landfill work, and it is also possible to reduce landfill costs.

Furthermore, when attempting to connect rows of steel pipes in a direction that intersects the extension direction of the wall to reinforce an existing wall, it is difficult to attach joints to the existing wall itself on site; When constructing a steel pipe row separately, by using steel pipe sheet piles with joints attached as part of the steel pipe piles that make up the steel pipe row, it is easy to connect the steel pipe rows in a direction that intersects with the extension direction of the wall. be able to. By connecting this steel pipe row and the jacket, the load shared by the U-shaped wall W is increased, and the load shared by the jacket is reduced, making it possible to construct a more economical pier structure.

FIG. 6 shows a quay wall structure including a first row of steel pipes arranged in the extending direction of the wall body and a second row of steel pipes arranged in the direction crossing it, as in one embodiment of the present invention described above. This is a graph showing the results of calculating the displacement relative to the total load using the finite element method (FEM) between the example) and the quay wall structure (comparative example) that includes only rows of steel pipes arranged in the extension direction of the wall. . In the Examples and Comparative Examples described below, in order to compare wall shapes, walls were constructed by connecting steel pipe sheet piles each having a diameter of 1100 mm and a pipe thickness of 12 mm using joints. In the example, nine steel pipe sheet piles are connected to each other to construct a wall body with a width of 10 m (first steel pipe row), and each of the steel pipe sheet piles at both ends has three walls arranged in a direction perpendicular to the extension direction of the wall body. Two steel pipe sheet piles were connected (second steel pipe row). The steel pipe sheet pile located at the end of the second steel pipe row is connected to the retaining pile structure via the jacket leg and the beam. On the other hand, in a comparative example, a wall of 10 m in width was constructed by connecting nine steel pipe sheet piles to each other, and the steel pipe sheet piles at both ends of the wall were not arranged in rows of steel pipes in a direction perpendicular to the extension direction of the wall. It was connected to the retaining pile structure via jacket legs and beams. In both Examples and Comparative Examples, copings were installed on the heads of the steel pipe sheet piles constituting the walls and the steel pipe rows, and it was assumed that vertical positional displacement would not occur between the steel pipe sheet piles.

In both the example and the comparative example, the ground surface on the land side coincides with the top of the steel pipe sheet pile, and the penetration depth of the support piles and retaining piles based on the ground surface on the land side is 46.3 m, and the penetration depth of the steel pipe sheet pile is 46.3 m. The depth was 32.5m. The distance from the top of the steel pipe sheet pile to the seabed was 16.9 m. The lower ends of the steel pipe sheet piles and retaining piles to which the jacket legs are attached were used as pin supports that do not cause vertical displacement, and the passive earth pressure from the sea side acting on the underground part of the wall was set. Furthermore, the length of the jacket leg of the support pile structure was 5.4 m. Under the above conditions, the graph in Figure 6 shows the relationship between the total load of active earth pressure from the land side acting on the wall and the displacement occurring at the upper end of the retaining pile structure (pier shoulder). ing. As shown in the graph, as a result of FEM calculations, in a quay wall structure (example) including a first steel pipe row arranged in the extension direction of the wall and a second steel pipe row arranged in the direction crossing it, It was found that displacement for the same total load was suppressed by about 17% compared to a quay wall structure (comparative example) that included only rows of steel pipes arranged in the extension direction of the wall.

Next, the effect of improving the bending rigidity of the wall by discretely arranging the steel pipes in the embodiment of the present invention will be verified. Table 1 shows the ratio of the steel weight per cross section to the bending stiffness EI per unit width in each case of Example 1 (continuous arrangement) and Example 2 (discrete arrangement). In Example 1, steel pipes with a diameter of 1100 mm and a plate thickness of 12 mm are continuously arranged (pitch = steel pipe diameter) in a section of about 10 m along the extension direction of the wall, and in Example 2, steel pipes with a diameter of 1200 mm and a plate thickness of 12 mm are arranged discretely. (Pitch>Steel pipe diameter). The bending stiffness EI and the steel weight ratio are expressed as a ratio of 1 for Example 1 (continuous arrangement). As shown in Table 1, by discretely arranging the steel pipes, the steel weight can be suppressed to about 80% if the bending rigidity per unit width is the same. As explained above with reference to FIG. 5, as the steel pipe diameter increases, the steel weight required to obtain the same bending stiffness EI is reduced, so it is possible to increase the pitch relative to the steel pipe diameter. Theoretically possible. However, in order to maintain uniformity of rigidity as a wall, the length of the section of the steel sheet pile wall that is blown away by expanding the pitch of the steel pipes, that is, the section of the steel sheet pile wall that does not overlap with the steel pipes in the direction of extension of the wall, is It is desirable to limit the amount to one sheet.

FIG. 7 shows the quay wall structure according to the embodiment of the present invention described above, when the number N of steel pipe sheet piles constituting the second steel pipe row arranged in the direction intersecting the wall body is changed. It is a graph showing the result of calculating the load sharing ratio of the structure combined with the first steel pipe array arranged in the extension direction of the wall. If a sufficient penetration depth is ensured for the first steel pipe row, the load sharing ratio increases as the number N of steel pipe sheet piles constituting the second steel pipe row increases, as shown in the graph. By increasing the load sharing ratio of the wall including the first steel pipe row and the second steel pipe row, the load borne by the support pile structure and the support pile structure becomes smaller, and for example, when the support pile is embedded It is possible to reduce the depth and reduce the amount of steel in members including beams.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. It is understood that these also fall within the technical scope of the present invention.

1... Quay structure, 2... Steel sheet pile wall, 3... First steel pipe row, 31... Steel pipe sheet pile, 311... Joint, 32... Steel pipe pile, 33... Connection member, 4... Second steel pipe row, 40, 41, 42, 43...Steel pipe sheet pile, 401...Joint, 401A...Female side joint member, 401B...Male side joint member, 402...Filler, 403A...Slip stopper, 403B...Slip stopper, 431...Joint, 5...Support pile structure , 51... Support pile, 52... Jacket leg, 53... Fitting member, 6... Pile structure, 61... Pile, 62... Jacket leg, 7... Beam, G... Ground, W... Wall body.

Claims (9)

A plurality of steel pipe piles connected to the steel sheet pile wall at a portion above the underground portion, and arranged at a ratio of one to the plurality of steel pipe piles, and connected to the steel sheet pile wall at the portion above the underground portion. a first steel pipe row including first steel pipe sheet piles arranged on the sea side of the steel sheet pile wall and spaced apart from each other at intervals matching the unevenness of the planar shape of the steel sheet pile wall;
A second steel pipe sheet pile in which at least one steel pipe sheet pile including a second steel pipe sheet pile functioning as at least a part of a supporting pile structure is arranged from the first steel pipe sheet pile in a direction crossing the extension direction of the steel sheet pile wall. A quay structure with a row of steel pipes. The quay structure according to claim 1, further comprising: a retaining pile structure located on the sea side than the supporting pile structure; and a connecting member connecting the supporting pile structure to the retaining pile structure. The support pile structure includes the second steel pipe sheet pile and a first jacket leg that fits on the outside of the head of the second steel pipe sheet pile,
The stay pile structure includes a stay pile and a second jacket leg that fits on the outside of the head of the stay pile,
The quay structure according to claim 2, wherein the connecting member includes a first connecting member disposed between the first jacket leg and the second jacket leg. The support pile structure includes a fitting member that fits inside the head of the first steel pipe sheet pile,
The quay structure according to claim 3, wherein the connecting member includes a second connecting member disposed between the first jacket leg and the fitting member. 3 or 3, wherein a joint is not formed between the head of the second steel pipe sheet pile and an adjacent steel pipe sheet pile, and the first jacket leg is fitted from the outside into a portion where the joint is not formed. Quay structure according to item 4. In a joint space surrounded by fitting a joint between the first steel pipe sheet pile and the steel pipe sheet pile included in the second steel pipe row, or between the steel pipe sheet piles included in the second steel pipe row. The quay wall structure according to any one of claims 1 to 5, wherein the anti-slip protrudes from the peripheral surface of the steel pipe sheet pile, and the joint space is filled with a filler. On the sea side of the steel sheet pile wall, a plurality of steel pipe piles and a first steel pipe sheet pile arranged for each of the plurality of steel pipe piles are spaced apart from each other at intervals matching the unevenness of the planar shape of the steel sheet pile wall. a step of arranging and constructing a first steel pipe row, and connecting the steel sheet pile wall and the first steel pipe row at a portion above the underground part;
Connecting at least one steel pipe sheet pile to the first steel pipe sheet pile to construct a second steel pipe row;
A method for constructing a quay wall structure, comprising: incorporating a second steel pipe sheet pile included in the second steel pipe row into a support pile structure. The step of incorporating the second steel pipe sheet pile into the support pile structure includes a step of fitting a first jacket leg to the outside of the head of the second steel pipe sheet pile,
According to claim 7, further comprising the step of driving a retaining pile on the sea side of the first steel pipe sheet pile using a second jacket leg connected to the first jacket leg via a connecting member as a guide. How to construct a quay structure. installing a first jacket leg, a second jacket leg located on the seaward side of the first jacket leg, and a connecting member that connects the first jacket leg to the second jacket leg;
further comprising the step of driving a retaining pile using the second jacket leg as a guide,
The method for constructing a quay structure according to claim 7, wherein the step of incorporating the second steel pipe sheet pile into a support pile structure includes the step of driving the first steel pipe sheet pile using the first jacket leg as a guide. .

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