JP2021167523A - Quay reinforcement structure and reinforcement method of quay structure - Google Patents

Abstract

[Problem] To effectively reinforce a quay wall structure including a steel sheet pile wall while further improving workability. [Solution] A quay wall reinforcement structure is provided, which comprises steel pipe piles arranged in the extension direction of the steel sheet pile wall at a position spaced a first distance from a convex portion of the steel sheet pile wall having an uneven planar shape, the steel pipe piles being spaced a second distance from each other at intervals that match the unevenness, and connecting members that connect the steel pipe piles to the steel sheet pile wall at a portion of the steel sheet pile wall above the water bottom surface. [Selected Figure] Figure 1

Description

The present invention relates to a quay reinforcement structure and a method for reinforcing the quay structure.

In the quay structure, a steel retaining wall driven deeper than the seabed resists backside earth pressure. As the steel material constituting the earth retaining wall, steel sheet piles and steel pipe sheet piles are generally used because they can be easily placed in the ground. When the water depth becomes large, the resistance to back earth pressure is insufficient only with steel sheet piles and steel pipe sheet piles. It has a structure that supports and resists backside earth pressure.

Techniques for such deepening work and seismic retrofitting of the quay structure are proposed in, for example, Patent Document 1 and Patent Document 2. In the quay reinforcement structure described in Patent Document 1, in a reinforced structure having an L-shaped cross section that reinforces the quay structure using a steel pipe sheet pile, a vertical portion forming one side of the L-shaped cross section is integrated with the steel pipe sheet pile to form an L-shape. The horizontal part forming the other side of the cross section is connected to a pile driven so as to face the steel pipe sheet pile at a position separated from the quay structure. In the quay reinforcement structure described in Patent Document 2, a reinforcement structure installed so as to contact the front surface of the steel sheet pile of the existing quay and a pile in which the head is connected to the reinforcement structure to support the wall body support member. Including the body.

On the other hand, Patent Document 3 describes a steel wall in which steel pipes are arranged side by side along the longitudinal direction of a steel sheet pile wall in which a plurality of hat-shaped steel sheet piles are connected by a joint. The steel sheet pile wall is formed in a corrugated sheet shape that repeats unevenness, the steel pipe is arranged so that a part of the steel sheet pile wall is recessed, and the head of the steel sheet pile wall and the head of the steel pipe are connected by concrete. There is. As a result, the earth pressure and water pressure acting on the steel sheet pile wall can be dispersed in the steel pipe. In the techniques described in Patent Document 1 and Patent Document 2, the wall body is reinforced by using a reinforcing structure connected to the pile body of the foundation, whereas in the technique described in Patent Document 3, the wall body is directly connected. Reinforced.

Japanese Unexamined Patent Publication No. 2010-156191 Japanese Unexamined Patent Publication No. 2010-156192 International Publication No. 2013/1644885

However, in the technique described in Patent Document 3 above, since the steel pipe is arranged close to the steel sheet pile wall, for example, when there is a construction material such as coping concrete on the head of the existing steel sheet pile wall. It will be necessary to remove it. Since coping concrete is constructed by wrapping a horizontal member, which is generally called abdominal uplift, together, if this part is completely removed, the retaining structure behind it will not be effective, and it will be necessary to reinforce the retaining structure. Become. Further, even if the steel pipe is arranged on the opposite side of the horizontal lumber and the horizontal lumber is left, work such as scraping a part of the concrete of the steel sheet pile wall head is required, which is troublesome in construction. As described above, there is still room for improvement in the conventional technique as described in Patent Document 3 from the viewpoint of workability of reinforcement work.

Therefore, an object of the present invention is to provide a quay reinforcing structure and a method for reinforcing the quay structure, which can further improve the workability while effectively reinforcing the quay structure including the steel sheet pile wall.

[1] Arranged in the extension direction of the steel sheet pile wall at a position separated by the first distance from the convex portion of the steel sheet pile wall having unevenness in the plane shape and separated from each other by the second distance at intervals consistent with the unevenness. A quay reinforcement structure including a steel pipe pile and a connecting member for connecting the steel pipe pile to the steel sheet pile wall above the water bottom surface of the steel sheet pile wall.
[2] The quay reinforcement structure according to [1], wherein the connecting member includes a steel material welded to a steel sheet pile wall and a steel pipe pile, respectively.
[3] The quay reinforcement structure according to [1] or [2], wherein the steel pipe piles are arranged on the opposite side of the horizontal member attached to the steel sheet pile wall.
[4] The quay reinforcement structure according to any one of [1] to [3], wherein the first distance is smaller than the second distance.
[5] The second distance is smaller than the diameter of the steel pipe pile, and the diameter of the steel pipe pile is larger than the pitch of the unevenness of the planar shape of the steel sheet pile wall. The described quay reinforcement structure.
[6] Regarding the extension direction of the steel sheet pile wall, the axis of the steel pipe pile is located in the planar concave portion of the steel sheet pile wall, and the connecting member is located on the pair of convex portions adjacent to the concave portion and the peripheral surface of the steel pipe pile, respectively. The quay reinforcement structure according to [5], which comprises a pair of steel materials to be welded.
[7] Arranged in the extension direction of the steel sheet pile wall at a position separated by the first distance from the convex portion of the steel sheet pile wall having unevenness in the plane shape, separated from each other by the second distance at intervals consistent with the unevenness. A method of reinforcing a quay structure including a step of placing a steel pipe pile to be constructed and a step of connecting the steel pipe pile to the steel sheet pile wall at a portion above the water bottom surface of the steel sheet pile wall.

According to the above configuration, since the steel pipe piles are separated from each other, the cross-sectional shape of the steel pipe piles can be optimized from the viewpoint of rigidity. As a result, the quay structure including the steel sheet pile wall can be effectively reinforced by using the steel pipe pile. In addition, by arranging the steel pipe piles separated from the convex portion of the steel sheet pile wall by a first distance, for example, it is not necessary to remove the work piece on the head of the existing steel sheet pile wall, and the workability is improved. Can be made to.

It is a top view of the quay structure which concerns on one Embodiment of this invention. It is a top view of the quay structure which concerns on the modification of one Embodiment. It is a graph which shows the relationship between the cross-sectional performance and the material cost when steel pipes are arranged discretely.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

FIG. 1 is a plan view of a quay structure according to an embodiment of the present invention. The quay structure 1 shown in FIG. 1 includes a steel sheet pile wall 2, a steel pipe pile 3 arranged in parallel with the steel sheet pile wall 2 in the extension direction (x direction in the drawing), and a steel sheet pile. A connecting member 4 for connecting the steel pipe pile 3 to the steel sheet pile wall 2 at a portion above the water bottom surface of the wall 2 is included.

Here, in the quay structure 1, the steel sheet pile wall 2 is constructed with one of the directions orthogonal to the extension direction (y direction in the drawing) as the sea side and the other as the land side, and the steel pipe pile 3 is the steel sheet pile wall 2. It may be located on either the sea side or the land side. The water bottom is defined as the sea floor in contact with the sea side of the steel sheet pile wall 2. By arranging the connecting member 4 above the water bottom surface of the steel sheet pile wall 2, it is not necessary to excavate the seabed ground to connect the steel pipe pile 3 to the steel sheet pile wall 2, and the construction becomes easy. The height of the connecting member 4 is not particularly limited as long as it is above the bottom surface of the water. For example, the connecting member 4 may be located above the water surface on the sea side of the steel sheet pile wall 2, or the steel sheet pile wall 2 may be located above the water surface. The connecting member 4 may be located above the ground surface on the land side.

In the illustrated example, the steel sheet pile wall 2 is composed of a U-shaped steel sheet pile and has irregularities in a planar shape. The steel pipe piles 3 are arranged so as to be separated from the planar convex portion of the steel sheet pile wall 2 by a distance d1 (d1> 0). The distance d1 is the distance from the convex portion of the planar shape unevenness of the steel sheet pile wall 2 to the peripheral surface of the steel pipe pile 3 in the direction orthogonal to the extension direction of the steel sheet pile wall 2. In the following description, the concave portion and the convex portion of the steel sheet pile wall 2 are defined with reference to the case where the steel pipe pile 3 is arranged.

Further, in the present embodiment, the steel pipe piles 3 are arranged at intervals consistent with the unevenness of the planar shape of the steel sheet pile wall 2. More specifically, the steel pipe pile 3 is arranged so that the axis is located in the planar recess of the steel sheet pile wall 2 in the extension direction of the steel sheet pile wall 2. Since the diameter Dp of the steel pipe pile 3 is larger than the pitch W2 of the flat unevenness of the steel sheet pile wall 2, every other steel pipe pile 3 is arranged in the recess of the steel sheet pile wall 2. In the illustrated example, since the steel sheet pile wall 2 is composed of the U-shaped steel sheet pile, the pitch W2 of the unevenness of the planar shape is twice the width W1 of the U-shaped steel sheet pile. Here, since the steel pipe pile 3 is arranged at a position separated by a distance d1 from the convex portion of the plane shape of the steel sheet pile wall 2, the steel pipe pile 3 is arranged without entering the concave portion of the steel sheet pile wall 2. Further, the steel pipe piles 3 are arranged so as to be separated from each other by a distance d2. The distance d2 is the distance between the peripheral surfaces of the adjacent steel pipe piles 3 in the extension direction of the steel sheet pile wall 2.

The connecting member 4 is a steel material welded to the steel sheet pile wall 2 and the steel pipe pile 3, respectively. More specifically, a pair of convex portions (also shown as web 2w2) adjacent to a recess of the steel sheet pile wall 2 (shown as web 2w1 of the U-shaped steel sheet pile) where the axial center of the steel pipe pile 3 is located, and A pair of steel plates to be welded to the peripheral surfaces of the steel pipe piles 3 are included. In this case, the steel plate is arranged so that the plate surface is perpendicular to the extension direction of the steel sheet pile wall 2. With such an arrangement, the pair of steel plates constituting the connecting member 4 have the same size. Further, by joining the connecting member 4 to the web 2w2 parallel to the extension direction of the steel sheet pile wall 2, the size of the connecting member 4 does not have to be changed even if the steel pipe pile 3 is slightly displaced.

Here, the connecting member 4 is arranged above the water bottom surface of the steel sheet pile wall 2 as described above, but is not necessarily arranged at the head of the steel sheet pile wall 2. In addition, as described above, in the present embodiment, the steel pipe pile 3 is arranged without entering the recess of the steel sheet pile wall 2, so that, for example, there is a construction material such as coping concrete on the head of the existing steel sheet pile wall 2. In this case as well, the connecting member 4 can be arranged below the work piece, that is, between the bottom surface of the water or the ground surface and the work piece, without removing the work piece. The connecting member 4 does not necessarily have to be welded to the steel sheet pile wall 2 and the steel pipe pile 3. For example, at least one of the joints between the connecting member 4 and the steel sheet pile wall 2 and the steel pipe pile 3 is bolted. May be good.

FIG. 2 is a plan view of the quay structure according to the modified example of one embodiment. The quay structure 1A shown in FIG. 2 includes a steel sheet pile wall 2, a steel pipe pile 3, and a connecting member 4 similar to the quay structure 1 shown in FIG. 1, as well as an uplift 5 and a tie rod 6. The abdomen 5 is an example of a horizontal member for integrating the steel sheet piles constituting the steel sheet pile wall 2. Since the steel pipe pile 3 can be arranged regardless of the sea side or the land side of the steel sheet pile wall 2, for example, when the steel sheet pile wall 2 and the raised portion 5 are already installed, the steel pipe pile 3 is attached to the steel sheet pile wall 2. It can be arranged on the opposite side of the raised abdomen 5. In the illustrated example, the side to which the abdominal raising 5 is attached is the sea side, and the steel pipe pile 3 is arranged together with the tie rod 6 on the land side of the steel sheet pile wall 2.

The tie rod 6 is a tensile force transmitting member that connects the steel sheet pile wall 2 (web 2w1 of the U-shaped steel sheet pile) to an anchor (not shown) penetrating the ground on the land side of the steel sheet pile wall 2. Every other steel pipe pile 3 is arranged in the recess of the steel sheet pile wall 2, and the tie rod 6 is attached to the recess of the steel sheet pile wall 2 in which the steel pipe pile 3 is not arranged. Therefore, in the illustrated example, the steel pipe piles 3 and the tie rods 6 are alternately arranged in the recesses of the steel sheet pile wall 2, and the arrangement interval d3 of the tie rods 6 is equal to the center interval of the steel pipe piles 3. In the present embodiment, the steel pipe piles 3 are arranged so as to be separated from each other by a distance d2. Therefore, for example, even when the steel sheet pile wall 2, the raised portion 5 and the tie rod 6 are already installed, the steel sheet pile 6 is not removed. It is possible to reinforce the wall 2.

Next, an example of a method for constructing a quay structure according to the present embodiment will be schematically described. First, the steel pipe pile 3 is driven at a position separated from the convex portion of the steel sheet pile wall 2 by a distance d1. As described above, the steel pipe piles 3 are arranged so as to be separated from each other by a distance d2 at intervals consistent with the unevenness of the planar shape of the steel sheet pile wall 2. Next, the steel pipe pile 3 is connected to the steel sheet pile wall 2 by using the connecting member 4 at a portion above the water bottom surface of the steel sheet pile wall 2. For example, the steel pipe pile 3 may be connected to the steel sheet pile wall 2 after all the steel pipe piles 3 have been driven, or the steel pipe pile 3 that has already been driven may be connected to steel in parallel with or before and after the steel pipe pile 3 is driven. It may be connected to the sheet pile wall 2. The above steps may be carried out as reinforcement work for the existing steel sheet pile wall 2 (and the raised 5 and the tie rod 6), or the new steel sheet pile wall 2 (and the raised 5 and the tie rod 6) are constructed. The step to be carried out may be carried out before the above-mentioned step.

When placing steel pipe piles and steel pipe sheet piles in harbor structures such as quays and piers, the vibro hammer method is often used. The vibro hammer method is a method in which a steel material is vibrated and driven into the ground. In the vibro hammer method, it is necessary to secure a certain thickness with respect to the steel pipe diameter in order to prevent damage to the steel pipe during construction. For example, the Vibrohammer Method Technology Study Group has stipulated standard values for the ratio of plate thickness t to steel pipe diameter D so that t / D ≥ 1.0% for steel pipe piles and t / D ≥ 1.4% for steel pipe sheet piles. ing. The reference value of the steel pipe sheet pile is larger because the joint may become a resistance at the time of driving.

On the other hand, the cross-sectional performance such as the moment of inertia of area and the cross-sectional coefficient of the wall body including the steel pipe can be effectively improved by increasing the steel pipe diameter rather than increasing the plate thickness. When the steel pipe sheet piles are connected by a joint to form a wall body, in addition to the restriction that the steel pipe sheet piles are continuously arranged via the joint in the extension direction of the wall body, the steel pipes are as described above. It is necessary to make the plate thickness larger than the diameter. On the other hand, when the steel pipes arranged in the extension direction of the wall body are not connected as simple steel pipe piles as in the present embodiment, the plate thickness is the same even if the diameter of the steel pipe piles is increased. Since it can be made smaller than the steel pipe sheet pile and the steel pipe piles do not have to be arranged continuously, the cross-sectional performance can be efficiently improved with respect to the amount of steel material.

In the present embodiment, the steel pipe piles 3 are arranged at intervals consistent with the unevenness of the planar shape of the steel sheet pile wall 2 from the idea of providing the steel sheet pile wall with the earth retaining function and giving the steel pipe pile the necessary yield strength. .. For example, when the width W1 = 400 mm of the U-shaped steel sheet pile in the example of FIG. 1, the uneven pitch W2 = 2 × W1 = 800 mm. When arranged with, the distance d2 between the steel pipe piles 3 becomes 400 mm. By setting the diameter Dp of the steel pipe pile 3 to 800 mm or more, which is twice the width of the U-shaped steel sheet pile, which is 400 mm, the steel pipe pile 3 is arranged at a position corresponding to the flat recess of the steel sheet pile wall 2, and has a flat shape. The web portion of the steel sheet pile located on the convex portion can be connected by the connecting member 4. In order to maintain the uniformity of rigidity as a wall body, it is desirable that the distance d1 between the steel sheet pile wall 2 and the steel pipe pile 3 is smaller than the distance d2 between the steel pipe piles 3. In the above example, when the wall thickness Dw of the steel sheet pile wall 2 (distance from the concave web 2w1 to the convex web 2w2) is 250 mm, for example, the distance d1 may be 200 mm. Similarly, it is desirable that the distance d2 between the steel pipe piles 3 is smaller than the diameter Dp of the steel pipe piles 3 and the diameter Dp of the steel pipe piles is larger than the pitch W2 of the planar unevenness of the steel sheet pile wall 2.

FIG. 3 is a graph showing the relationship between the cross-sectional performance and the material cost when the steel pipes are arranged discretely in comparison with the case where the steel pipes are arranged continuously (steel pipe sheet pile wall). In the graph of FIG. 3, a case where steel pipes are arranged at a pitch of 1600 mm on a steel sheet pile wall composed of a U-shaped steel sheet pile having a width of 400 mm as in the above example, and a moment of inertia of area per unit width with the steel pipe sheet pile wall. And the relationship with the material cost per 1 m of length is shown. For each example, the moment of inertia of area was calculated by considering only the rigidity of the steel pipe. The material cost was calculated based on the dimensions of each member and the construction price. The joint of the steel pipe sheet pile was a P-P type specified in JIS A5530. Further, for each example, assuming that a plurality of steel pipe diameters are set and the plate thickness is constructed by the vibro hammer method, the steel pipe pile is t / D ≧ 1.0% and the steel pipe sheet pile is t / D ≧ 1.4%. The minimum value that satisfies is satisfied.

For example, 1000 mm diameter, thickness 14mm of steel pipe using steel sheet pile wall when (pitch of the steel pipe is steel pipe diameter + joint length) of the second moment per unit width 4.22 × ¹⁰ 5 ^(cm 4) become. On the other hand, when the steel pipes are arranged discretely as in the present embodiment, in order to construct a wall body having the same moment of inertia of area, steel pipes having a diameter of 1200 mm and a plate thickness of 12 mm are arranged at a pitch of 1600 mm. Just do it. In this case, the second moment per unit width becomes ^{4.94 × 10 5 (cm 4)} . As a result, the material cost can be reduced by about 40% as compared with the case of the steel pipe sheet pile with the same moment of inertia of area. This also applies to other examples of steel pipe diameters. As described above, for example, by arranging steel pipes discretely using an existing steel sheet pile wall, a predetermined cross section is required at a lower material cost than the steel pipe sheet pile wall. It is possible to build a wall body that meets the performance.

One embodiment of the present invention as described above can be applied to an existing revetment when planning deepening work or seismic retrofitting. Conventionally, in such a case, a wall structure is newly installed on the sea side of the existing wall, and the space between the existing wall and the new wall is reclaimed. Since the increase in earth pressure due to deepening and the seismic load are taken into consideration 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 material constituting the wall structure, which increases the cost. In addition, reclamation work is also required, so the total construction cost tends to be high.

On the other hand, when this embodiment is applied for deepening work or seismic retrofitting of a steel sheet pile wall constructed as an existing revetment, steel pipes are discretely arranged at positions adjacent to the existing wall in the extension direction of the wall body. By arranging the piles, the lack of rigidity is compensated. It is conceivable to construct a steel pipe sheet pile wall as a wall structure with high flexural rigidity, but in the case of a steel pipe sheet pile wall, the function as a wall itself is required, so the steel pipe sheet piles are arranged continuously rather than discretely. There is a need. In the case of the present embodiment, the existing steel sheet pile wall already exists as a surface to receive earth pressure, and the steel pipe pile and the steel pipe sheet pile may be arranged for the insufficient rigidity, so that the bending rigidity can be rationally supplemented. Further, since the step of installing a new wall on the sea side is omitted, the landfill work is unnecessary and the landfill cost can be suppressed. It should be noted that the embodiment of the present invention is not limited to the coastal quay structure, and may be a riverbank or lakeshore quay structure. In the case of a riverbank, the sea side in the above explanation is read as the river side, and the seabed is read as the river bottom. Similarly, in the case of a lake shore, the sea side is read as the lake side, and the seabed is read as the lake bottom.

In the above example, the steel sheet pile wall is made of a U-shaped steel sheet pile, but the type of steel sheet pile is not limited as long as the steel sheet pile wall having irregularities in the planar shape can be formed. For example, the steel sheet pile wall may be formed of a hat-shaped steel sheet pile or a Z-shaped steel sheet pile. Further, the support structure of the steel sheet pile wall and the steel pipe pile is not particularly limited. For example, the steel sheet pile wall and the steel pipe pile may be self-supporting as in the example shown in FIG. 1, or a support pile, a jacket structure, or the like may be attached to the steel pipe pile, and is shown in FIG. A tie rod may be attached to the steel sheet pile wall as in the example.

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

1,1A ... Quay structure, 2 ... Steel sheet pile wall, 3 ... Steel pipe pile, 4 ... Connecting member, 5 ... Raised, 6 ... Tie rod.

Claims (7)

They are arranged in the extension direction of the steel sheet pile wall at a position separated by a first distance from the convex portion of the steel sheet pile wall having unevenness in a planar shape and separated from each other by a second distance at intervals consistent with the unevenness. Steel pipe pile and
A quay reinforced structure including a connecting member for connecting the steel pipe pile to the steel sheet pile wall at a portion above the water bottom surface of the steel sheet pile wall. The quay reinforcing structure according to claim 1, wherein the connecting member includes a steel material welded to the steel sheet pile wall and the steel pipe pile, respectively. The quay reinforcing structure according to claim 1 or 2, wherein the steel pipe piles are arranged on the side opposite to the horizontal member attached to the steel sheet pile wall. The quay reinforcing structure according to any one of claims 1 to 3, wherein the first distance is smaller than the second distance. The second distance is smaller than the diameter of the steel pipe pile.
The quay reinforcing structure according to any one of claims 1 to 4, wherein the diameter of the steel pipe pile is larger than the pitch of the unevenness of the planar shape of the steel sheet pile wall. In the extension direction of the steel sheet pile wall, the axis of the steel pipe pile is located in the planar concave portion of the steel sheet pile wall, and the connecting member is a pair of convex portions adjacent to the concave portion and the circumference of the steel pipe pile. The quay reinforcement structure according to claim 5, comprising a pair of steel materials welded to each surface. They are arranged in the extension direction of the steel sheet pile wall at a position separated by a first distance from the convex portion of the steel sheet pile wall having unevenness in the plan shape, separated from each other by a second distance at intervals consistent with the unevenness. The process of placing steel pipe piles
A method for reinforcing a quay structure including a step of connecting the steel pipe pile to the steel sheet pile wall at a portion above the water bottom surface of the steel sheet pile wall.

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