JP6322560B2 - Renewal method of existing revetment or quay and revetment or quay structure - Google Patents

Description

  The present invention relates to an existing revetment renewal method and a revetment structure in which an old steel sheet pile is removed to renew a revetment in an existing revetment and quay using a steel sheet pile (hereinafter simply referred to as a revetment).

  Conventionally, a sheet pile type or a caisson type is used for a revetment constituted by a steel sheet pile. For example, at the shoreline of a port facility, a revetment mainly for the purpose of retaining soil is provided for the purpose of effective use of land and securing of navigation routes and anchorage. The seawall is responsible for protecting the land from water currents and waves.

  For example, the sheet pile type revetment resists the external force such as earth pressure and water pressure with the rigidity and penetration length of the steel sheet pile, is relatively easy to construct, and can cope with soft ground. There are many achievements.

  On the other hand, Japan's infrastructure facilities are entering an era when countermeasures against aging are urgently needed. Port facilities are also aging, and steel sheet pile revetments, which are used under severe conditions at the water's edge, are particularly prone to corrosion and aging. Therefore, renewal of such a revetment is necessary.

  As a method of repairing such a revetment, there is a method of constructing a self-supporting structure on the back of the revetment, excavating between the revetment and the self-supporting structure, constructing a foundation at the excavated site, and installing a caisson Patent Document 1).

  In addition, there is a method of placing a new steel sheet pile close to the back of an existing steel sheet pile in a state where the box is submerged on the entire steel sheet pile quay and pressed down on the entire surface of the steel sheet pile (Patent Document 2).

JP-A-8-284126 Japanese Patent Laid-Open No. 11-323872

  However, what is described in Patent Document 1 is to construct a caisson and not a method of updating a steel sheet pile. In addition, since it is assumed that the existing quay will be removed, the construction period becomes longer, which causes a longer period during which the port facility cannot be used.

  In addition, the method described in Patent Document 2 is based on the premise that a huge box is set on the entire surface of the steel sheet pile in order to remove the tie rod connected to the steel sheet pile. Therefore, a process on the water is required, and the box is submerged, so securing the route during construction becomes a problem. In addition, because construction at the port is affected not only by wind and rain but also by waves, this technology that requires a process on the water is not necessarily efficient.

  On the other hand, steel materials used in harbor steel structures such as revetments and quay walls are in contact with seawater, exposed to sea breezes, and placed in a very severe corrosive environment. In order to prevent such corrosion of steel materials such as steel sheet piles, cathodic protection is widely used as a known technique. This technology prevents the steel from ionizing (corrosion) by continuously flowing a direct current from the outside into the steel against the corrosion current that flows from the steel to the electrolyte (seawater). It is a method to do.

  However, such anti-corrosion technology, which is a known technique, is a preventive measure for preventing corrosion of steel materials such as steel sheet piles, and even if corrosion protection is applied to steel materials such as steel sheet piles, The function deteriorated by corrosion cannot be recovered. Thus, at present, no effective renewal method for revetment using steel sheet piles has been proposed.

  The present invention has been made in view of the above-described problems, and its purpose is to provide an existing revetment renewal method and a revetment structure that can be renewed efficiently for revetments using existing steel sheet piles. Is to provide.

  In order to achieve the above-mentioned object, the first invention is a method for renewing an existing revetment in which a steel sheet pile is used, and a process for improving the ground on the back side of the existing steel sheet pile and constructing a ground improvement body And the step of removing the existing steel sheet pile and the tie rod that supports the existing steel sheet pile, and the step of installing a covering member at the position where the existing steel sheet pile is installed, on the front side of the ground improvement body And a step of filling a filler between the covering member and the ground improvement body, and a renewal method of an existing revetment.

  The planar shape of the ground improvement body may be any one of a sector shape, an ellipse shape, a ribbon shape, or a rectangle shape including a semicircle.

  When the height of the ground improvement body is H, it is desirable that the width of the ground improvement body from the revetment side to the inland side is 0.3H or more.

  The covering member may be a new steel sheet pile, the new steel sheet pile may be installed on the underwater ground, and the upper part of the new steel sheet pile may be supported by a new tie rod.

  The covering member is a new metal plate, a resin plate, or a concrete plate, and an anchor is directly installed on the front surface of the ground improvement body, and the covering member is fixed to the front surface of the ground improvement body by the anchor. Good.

  According to 1st invention, since the ground improvement body is constructed | assembled in the back side of a steel sheet pile, when the existing steel sheet pile is removed, the outflow and collapse of a back ground can be prevented. Moreover, since a ground improvement body becomes independent, a new coating | coated member can be arrange | positioned in the same position after removal of an existing steel sheet pile. For this reason, the position of the seawall normal or the coastline does not change.

  Moreover, since a ground improvement body is constructed | assembled in the back surface of a steel sheet pile, the process on the water is unnecessary in the case of removal and installation of a steel sheet pile. Therefore, there is no hindrance to the navigation of the ship. Moreover, according to this invention, since a large sized machine and a ship are not required, it can update while using a steel sheet pile revetment and a quay, and it is not necessary to provide the period which becomes difficult to use with an update.

  In addition, the planar shape of the ground improvement body is closer to the revetment line than the width in the direction perpendicular to the revetment line (the direction from the revetment side to the inland side), such as a fan shape, semi-circle, ribbon shape, or rectangle. By adopting a flat shape having a larger width in the parallel direction, the construction cost can be reduced as compared with the case of constructing a circular ground improvement body.

  In addition, when the height of the ground improvement body is H, the width of the ground improvement body from the revetment side to the inland side is 0.3H or more, so that when the steel sheet pile is removed, the back ground flows out or It can be surely prevented from collapsing.

  If the covering member is a new steel sheet pile, the new steel sheet pile is installed on the underwater ground, and the upper part of the new steel sheet pile is supported by a new tie rod, the same as the existing revetment before the update It can be a structure.

  Also, if the covering member is a new metal plate, resin plate or concrete plate, and the anchor is installed directly on the front surface of the ground improvement body, and the covering member is fixed to the front surface of the ground improvement body with the anchor, Easy to install. Moreover, erosion of the front surface of the ground improvement body can be prevented by the covering member. Moreover, since the covering member is only fixed to the ground improvement body with an anchor, it is easy to replace the covering member in the future.

  The second invention is a revetment structure, a ground improvement body, an anchor installed directly on the front surface of the ground improvement body on the water area side, a covering member that covers the front surface of the ground improvement body with the anchor, A revetment structure comprising a filler filled between the covering member and the ground improvement body.

  According to the second invention, since the covering member is directly fixed to the front surface of the ground improvement body, the replacement is easy, and the deterioration and erosion of the ground improvement body can be prevented. In particular, since the covering member does not need the earth retaining function of the back ground, it is possible to apply a light and thin member, and since excessive strength is unnecessary, it is also possible to apply a lightweight member such as a resin. it can.

  ADVANTAGE OF THE INVENTION According to this invention, the renewal method and the revetment structure of the existing revetment which can be updated efficiently about the revetment using the existing steel sheet pile can be provided.

It is sectional drawing of the revetment 1, Comprising: The figure which shows the state which constructed | assembled the surface layer improvement part 9. FIG. It is sectional drawing of the revetment 1, Comprising: The figure which shows the process of constructing the ground improvement body. (A)-(c) is a figure which shows the planar shape of the ground improvement body 13, and the example of arrangement | positioning. (A)-(c) is a figure which shows the planar shape of the ground improvement body 13, and the example of arrangement | positioning. It is sectional drawing of the revetment 1, Comprising: The figure which shows the process of removing the existing steel sheet pile 3. FIG. It is sectional drawing of the revetment 1, Comprising: The figure which shows the process of installing the new steel sheet pile 3a. It is sectional drawing of the revetment 1, Comprising: The figure which shows the state which filled with the filler 17 and installed the tie rod 5a. It is sectional drawing of the revetment 1, Comprising: The figure which shows the state which update was completed. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state bored using the boring apparatus 23. FIG. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state which update was completed. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state bored using the boring apparatus 23. FIG. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state which update was completed. Sectional drawing of the revetment 1a before an update. It is sectional drawing of the revetment 1a, Comprising: The figure which shows the process of constructing the ground improvement body 13a. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state which installed the anchor 29 in the front surface of the ground improvement body 13. FIG. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state which installed the coating | coated member 31 in the front surface of the ground improvement body 13. FIG. It is sectional drawing of the revetment 1 which shows another construction method, Comprising: The figure which shows the state which update was completed.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of the revetment 1. The revetment 1 is a harbor structure, a coastal structure, a river structure, or the like.

  An existing steel sheet pile 3 is provided on the revetment 1. The steel sheet pile 3 is embedded deeper than the water bottom 7. Further, the steel sheet pile 3 is fixed to the back ground by a tie rod 5. The steel sheet pile 3 has a function of retaining the back ground.

  For such a revetment 1, first, a surface layer improvement portion 9 is constructed above the tie rod 5. The surface layer improvement unit 9 is constructed by cement improvement or chemical injection. The surface layer improvement part 9 aims at ensuring the construction scaffold of ground improvement, etc. The thickness of the surface layer improving portion 9 is desirably 30 cm or more (more desirably 50 cm or more).

  In addition, when the back ground has sufficient strength, the surface layer improving portion 9 is not necessarily required. For example, when the surface layer portion is paved or the like, and there is no risk of cement milk jetting from the surface layer portion or depression of the surface layer portion by a high-pressure jet stirring method described later, it can be omitted.

  Next, as shown in FIG. 2, the ground improvement body 13 is constructed on the back ground of the steel sheet pile 3. The ground improvement body 13 is intended for earth retaining when the steel sheet pile 3 to be described later is removed. The ground improvement body 13 is constructed by, for example, a high-pressure jet stirring method.

  In the high-pressure jet stirring method, first, the high-pressure jet stirring device 11 is installed, and an improved rod is inserted into a boring hole having a diameter of about φ100 to 250 mm. Next, while injecting high-pressure cement milk and compressed air into the ground through the rod, the rod is rotated or rocked (arrow D in the figure) to be mixed with the ground. By performing this while pulling up the rod (arrow E in the figure), the columnar ground improvement body 13 having a diameter of 2 m or more can be formed in the ground. In addition, the ground improvement body 13 may be constructed by a construction method such as a mechanical stirring method or a chemical solution injection method other than the high-pressure jet stirring method.

  When the ground improvement body 13 is constructed by the high-pressure jet stirring method, a high pressure acts in the ground. For this reason, there exists a possibility that cement milk may protrude from a surface layer part. In addition, immediately after the ground improvement, there is a state in which a liquid of cement milk having a diameter of φ2 m or more exists in the ground, and there is a possibility that the surface layer portion will sink due to the ground collapse. On the other hand, in this embodiment, it is possible to prevent the ejection of cement milk from the surface layer portion and the depression of the surface layer portion by constructing the surface layer improving portion 9 described above.

  Here, the height of the ground improvement body 13 is H. The width of the ground improvement body 13 (the width of the ground improvement body from the revetment side to the inland side in the direction orthogonal to the revetment line) is defined as W. At this time, W is desirably 0.3 times or more of the height H of the ground improvement body 13, and more desirably 0.5 times or more. By doing in this way, the back ground can be reliably earthed.

  The depth of the ground improvement body 13 (A in the figure and the depth of the lower part of the ground improvement body 13 when the water bottom 7 is used as a reference) may be about 1 m. In addition, the height H of the ground improvement body 13 may not be constant over the entire range, and may be lowered stepwise as it goes from the revetment side to the inland side. In this case, it is desirable that the entire width W is 0.3H or more or 0.5H or more with respect to the maximum height H.

  Fig.3 (a)-FIG.3 (c) are figures which show an example of arrangement | positioning and a planar shape of the ground improvement body 13, respectively. In the example shown to Fig.3 (a), it arrange | positions so that the substantially circular ground improvement body 13 may mutually contact. A part of the ground improvement body 13 may contact the steel sheet pile 3. Thus, if it can be made to function as the earth retaining of the back ground of the steel sheet pile 3, a non-ground improvement part may exist between the ground improvement bodies 13 mutually.

  Moreover, as shown in FIG.3 (b), the adjacent ground improvement bodies 13 may be mutually wrapped, and the ground improvement of a back ground may be performed without a gap.

  Moreover, as shown in FIG.3 (c), you may arrange | position the ground improvement body 13 in a grid | lattice form so that a non-ground improvement part may be formed in the inside enclosed by the ground improvement body 13. FIG. Thus, in this invention, arrangement | positioning of the ground improvement body 13 is not specifically limited.

  In consideration of the influence of the high-pressure jet stirring on the water area and the influence on the corroded or aged steel sheet pile 3, the steel sheet pile 3 and the ground improvement body 13 may not be brought into close contact with each other, and a certain gap may be secured. For example, you may provide the clearance gap 15 between the steel sheet piles 3, as shown to Fig.4 (a). In this case, the ground improvement body 13 facing the steel sheet pile 3 can also be formed in a semicircular shape. That is, the planar shape of the ground improvement body 13 is larger in the width in the direction parallel to the revetment line (vertical direction in the figure) than in the direction perpendicular to the revetment line (left and right direction in the figure).

  Even in this case, the ground improvement bodies 13 may be wrapped together, and may be arranged so as to contact each other as shown in FIG.

  Further, the planar shape of the ground improvement body 13 is not limited to a semicircular shape. As an example in which the planar shape of the ground improvement body 13 is larger in width in the direction parallel to the revetment line (up and down direction in the figure) than in the direction perpendicular to the revetment line (left and right direction in the figure), FIG. It may be a ribbon type, a sector shape (not shown), or a rectangle shape (not shown) as shown in (c). In order to form the ground improvement body 13 having such a shape, the above-described improvement rod may be rotated or rocked to improve the ground only in a predetermined angle range.

  By combining the ground improvement bodies 13 having a plurality of shapes, it is possible to arrange the ground improvement bodies 13 without waste according to the shape of the required improvement area. Further, it is economical because the amount of cement required for construction can be reduced and the amount of slime generated by the construction can be reduced. By setting it as such a flat-shaped ground improvement body 13, the ground improvement body 13 can be efficiently formed only in a required site | part.

  Next, as shown in FIG. 5, the ground of the installation portion of the tie rod 5 is excavated from the surface layer, and the existing tie rod 5 installed in a planar and comb shape is removed. In addition, when it is confirmed that the existing tie rod 5 is healthy, it is not always necessary to remove it, and the connection with the steel sheet pile 3 may be removed.

  Next, the existing steel sheet pile 3 is pulled out from the ground using a crane or the like using the ground improvement body 13 thus created as a retaining wall (arrow G in the figure). The steel sheet pile 3 is basically pulled out by a crane or the like, but if this is difficult, the steel sheet pile 3 may be cut at the boundary with the bottom 7 and removed. In this case, a part of the cut steel sheet pile 3 is left in the bottom ground. Moreover, you may remove, cutting the steel sheet pile 3 into plurality.

  Next, as shown in FIG. 6, a new steel sheet pile 3a is installed from the ground using a crane or the like (H in the figure). The steel sheet pile 3a may be installed using vibration, water flow, or the like. Further, it may be installed with a static load such as hydraulic pressure. In addition, the steel sheet pile 3a is installed in the same position as the position where the existing steel sheet pile 3 was installed. Therefore, as described above, when the steel sheet pile 3 that has been cut remains in the raw ground on the seabed, the newly installed steel sheet pile 3 a may be driven so as to wrap with the steel sheet pile 3. Moreover, you may join the cut steel sheet pile 3 and the new steel sheet pile 3a with welding, a volt | bolt, etc. The steel sheet pile 3a is a covering member that covers the front surface of the ground improvement body 13.

  Next, as shown in FIG. 7, a tie rod 5a is newly installed and joined to the steel sheet pile 3a. In addition, when the existing tie rod 5 can be used as it is, the existing tie rod 5 and the steel sheet pile 3a are joined. Moreover, a space | gap may remain between the ground improvement body 13 and the steel sheet pile 3a. For example, as described above, when the gap 15 is formed between the steel sheet pile 3 and the ground improvement body 13, a gap remains between the ground improvement body 13 and the steel sheet pile 3a. Therefore, a mortar, cement milk, or a filler 17 such as gravel or sand that is inseparable in water is filled between the steel sheet pile 3a and the ground improvement body 13.

  Next, as shown in FIG. 8, a portion excavated in a comb shape for renewal of the tie rod 5 is backfilled with a ground material or a cement-based material, and the surface layer portion is restored. The steel sheet pile which comprises the revetment 1 can be updated by the above.

  As mentioned above, according to this Embodiment, in order to form the independent ground improvement body 13 in the back surface of the existing steel sheet pile 3, and to function as a earth retaining, when removing the steel sheet pile 3, it is that a revetment collapses. Can be prevented. Moreover, since the ground improvement body 13 becomes independent, after removing the existing steel sheet pile 3, the new steel sheet pile 3a can be arrange | positioned in the same position. For this reason, the position of the seawall normal or the coastline does not change.

  In addition, since all work is performed on the ground, a process on the water is unnecessary. Therefore, there is no hindrance to the navigation of the ship.

  Moreover, the planar shape of the ground improvement body 13 is larger than the width in the direction perpendicular to the revetment line (direction from the revetment side to the inland side), such as a fan shape, semicircle, ribbon shape, or rectangle including a semicircle. By making it a flat shape whose width in the direction parallel to the revetment line is larger, the construction cost can be reduced as compared with the case where the circular ground improvement body 13 is constructed.

  Moreover, when the height of the ground improvement body 13 is set to H, when the width W of the ground improvement body from the revetment side to the inland side is set to 0.3H or more, when the steel sheet pile 3 is removed, the back ground Can be reliably prevented from flowing out or collapsing.

  In addition, according to this invention, it is possible not only to update the existing steel sheet pile revetment but also to improve functions such as improving the seismic resistance of the revetment.

(Second Embodiment)
Next, a second embodiment will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 9 is a view showing a state (FIG. 6) after the new steel sheet pile 3a is installed. In the present embodiment, using the boring device 23, the boring device 23 is used to perform the boring at an angle of about 20 ° to 70 ° from the upper side of the revetment side toward the lower side of the inland side. . It is desirable that the depth of the boring is deeper than the depth of the ground improvement body 13 and the hole is drilled to a solid ground to which a distal end portion of an anchor 25 described later can be fixed.

  Next, as shown in FIG. 10, the anchor 25 is installed in the drilled borehole, and a filler 27 such as cement milk is filled in the borehole. The filler 27 may be filled only in the tip portion of the anchor 25, but it is preferable to fill the entire depth in consideration of the severe condition of the sea. Furthermore, construction is completed by refilling the upper part of the ground improvement body 13.

  Moreover, as shown in FIG. 11, you may form a boring hole in a substantially horizontal direction using the boring apparatus 23. FIG. The boring device 23 is placed on the inland side of the ground improvement body 13, and the vicinity of the head of the ground improvement body 13 is drilled horizontally. The hole drilling may penetrate the steel sheet pile 3a. Or you may open a hole in the steel sheet pile 3a from the sea side.

  In addition, when forming a boring hole in a substantially horizontal direction, the boring device 23 may be installed on the water and the hole may be drilled. However, when the boring device 23 is installed on the water, not only a large-scale scaffolding is required but also the navigation of the ship may be hindered, so drilling from the land side is suitable.

  Next, as shown in FIG. 12, an anchor 25 or a tie rod is installed in the drilled borehole, and a filler 27 such as cement milk is filled in the borehole. It is preferable to connect the tip of the anchor 25 or the tie rod to the newly formed steel sheet pile 3a with a bolt or the like. As described above, the filler 27 may be filled only in the tip portion of the anchor 25, but it is preferable to fill the entire length in consideration of the severe condition of the sea. Furthermore, construction is completed by refilling the upper part of the ground improvement body 13.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. Further, in the present embodiment, in order to improve the stability of the ground improvement body 13 with respect to falling and sliding and to reduce the improvement width, anchors are formed on the drilling holes drilled obliquely or horizontally in the ground improvement body 13 formed. 25 or a tie rod is installed. Thus, by installing the anchor 25 and the like, the width W of the ground improvement body 13 can be reduced.

(Third embodiment)
Next, a third embodiment will be described. As shown in FIG. 13, the third embodiment is a form applied to the revetment 1 a in which a stone 19 such as chestnut is used on the back surface of the steel sheet pile 3. When the stone 19 is used on the back surface of the steel sheet pile 3, the mechanical stirring method, the high-pressure jet stirring method, the chemical injection method, etc. may not be applied.

This is because when the size of the stone 19 is large, it is difficult to insert the improved device into the ground by the mechanical stirring method, and in the high-pressure jet stirring method, the high-pressure cement milk and compressed air injected from the improved rod are the stone 19 This is because there are cases in which a ground improvement body of good quality cannot be created due to inhibition by the above. It is also conceivable to fill the gaps in the stone 19 with chemicals or cement milk by a chemical injection method, but generally the stone 19 has a high water permeability coefficient (for example, the stone 19 has a water permeability of 1 × 10 ⁻² cm / cm ² ). There is a risk that chemicals and cement milk may leak into the sea area.

  In such a case, as shown in FIG. 14, a ground improvement body 13a is formed in a portion where the stone material 19 is used by using a known technique called plastic grout or a material called plastic grout. To do. First, the chemical solution injection device 21 is installed above the formation portion of the ground improvement body 13a, and plastic grout or plastic grout is injected into the ground made of the stone material 19. Here, plastic grout or plastic grout is a material that is inseparable in water and maintains viscosity for several hours from gelation until it hardens, and is used for shielding tunnel backfill and tunnel cavity fillers. It has been done. In addition, mortar and cement milk that are inseparable in water may be used.

  In addition, in order for the ground improvement body 13a formed by injecting or filling plastic ground or plastic grout, non-separable mortar or cement milk into the ground to exhibit the function as a retaining wall, the solidified S The wave velocity is preferably about 500 m / s or more.

  Further, a gap may be formed between the ground improvement body 13 a and the steel sheet pile 3. Moreover, when the range of the stone material 19 is narrow and the width of the ground improvement body 13a cannot be ensured by plastic grout or plastic grout, underwater inseparable mortar or cement milk, a high pressure jet stirring method is provided on the back of the ground improvement body 13a. For example, the ground improvement body 13 may be additionally constructed to secure the improvement width. In addition, the width | variety etc. of the required ground improvement body 13a are the same as that of the ground improvement body 13 mentioned above.

  In this way, after the ground improvement body 13a is constructed, the construction is completed by removing the existing steel sheet pile 3 or installing a new steel sheet pile 3a in the same procedure as described above.

  According to the third embodiment, an effect similar to that of the first embodiment can be obtained. Moreover, this invention is applicable also to the revetment 1a in which the stone material 19 is provided in the back surface of the steel sheet pile 3. FIG.

(Fourth embodiment)
Next, a fourth embodiment will be described. FIG. 15 is a view showing a state (FIG. 5) after the existing steel sheet pile 3 is removed. In this embodiment, the ground improvement body 13 is a new caisson-type revetment, and the anchor 29 is installed on the front surface (side surface on the sea side) of the ground improvement body 13. A chemical anchor or the like is used as the anchor 29, and a diver is installed in the underwater part.

  Next, as shown in FIG. 16, a covering member 31 such as a precast concrete plate (hereinafter referred to as a PC plate), a metal plate, or various resin plates is installed using the anchor 29 installed on the ground improvement body 13. In addition, since the covering member 31 covers and protects the surface of the ground improvement body 13 and does not have a function of retaining the ground on the back surface, a lightweight and thin member can also be used. Therefore, installation of the covering member 31 does not require a large machine such as a crane.

  In the illustrated example, the covering member 31 is disposed so as to protrude from the ground portion. However, the covering member 31 may be disposed only in the underwater portion, and another protective plate may be installed on the ground portion. Good. In the following description, the protective plate is also referred to as a covering member 31.

  Here, the covering member 31 is disposed at the same position as the existing steel sheet pile 3. Therefore, it is necessary to join the anchor 29 disposed on the front surface of the ground improvement body 13 and the covering member 31 disposed at the same position as the existing steel sheet pile 3. For this reason, when the ground improvement body 13 is constructed, if the gap 15 with the existing steel sheet pile 3 is too large, the anchor 29 may not reach. Therefore, as shown to Fig.4 (a), when forming the clearance gap 15 between the ground improvement body 13 and the steel sheet pile 3, the width F needs to be set to such an extent that the anchor 29 reaches. Specifically, the width F of the gap 15 is desirably 30 cm or less.

  After fixing the covering member 31 to the front surface of the ground improvement body 13, a filler 17 such as mortar, cement milk, gravel, sand or the like that is inseparable in water is filled between the covering member 31 and the ground improvement body. . In consideration of sucking out by waves and the like, mortar and cement milk that are inseparable in water are suitable.

  In this state, the renewal of the revetment 1 is completed by refilling the surface part. In addition, you may join the reinforcement member 33 to the upper part of the coating | coated member 31 as needed. The reinforcing member 33 is a rod-shaped member such as an anchor.

  In this case, after the covering member 31 is installed, a reinforcing member 33 such as an anchor is installed above the ground improvement body 13, and a preparatory work is installed on the upper surface of the ground improvement body 13 or the back surface of the ground improvement body 13. Link. It should be noted that the joining and the temporary work of the covering member 31 and the reinforcing member 33 are performed in parallel with the backfilling work on the upper portion of the ground improvement body 13. Further, a steel material (H-shaped steel, channel steel, etc.) may be installed on the front surface (sea side) of the covering member 31 and the reinforcing member 33 may be connected.

  According to the fourth embodiment, an effect similar to that of the first embodiment can be obtained. Further, the covering member 31 can be easily installed, and the covering member 31 can be easily replaced in the future in accordance with the state of damage of the covering member 31 due to corrosion or the like.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, it goes without saying that the above-described configurations can be combined with each other.

1, 1a ......... Revetment 3, 3a ......... Steel sheet pile 5, 5a ......... Tie rod 7 ...... Water bottom 9 ...... Surface improvement part 11 ...... High-pressure jet agitator 13, 13a ......... Ground improvement Body 15 ......... Gap 17 ......... Filling material 19 ......... Stone 21 ......... Chemical liquid injection device 23 ......... Boring device 25 ......... Anchor 27 ......... Filling material 29 ......... Anchor 31 ......... Covering member 33... Reinforcing member

Claims (6)

A renewal method of an existing revetment or quay where steel sheet piles are used,
Improving the ground on the back side of the existing steel sheet pile, building a ground improvement body,
Removing the tie rod supporting the existing steel sheet pile and the existing steel sheet pile;
The front side of the ground improvement body, the step of installing a covering member at the position where the existing steel sheet pile was installed,
Filling a filler between the covering member and the ground improvement body;
A renewal method of an existing revetment or quay characterized by comprising:   2. The method for updating an existing revetment or quay according to claim 1, wherein a planar shape of the ground improvement body is any one of a fan shape, an ellipse shape, a ribbon shape, or a rectangle shape including a semicircle.   The existing revetment according to claim 1 or 2, wherein the height of the ground improvement body is H, the width of the ground improvement body from the revetment or quay side to the inland side is 0.3H or more. Or how to update the quay.   The said covering member is a new steel sheet pile, The said new steel sheet pile is installed in an underwater ground, and the upper part of the said new steel sheet pile is supported by a new tie rod. Renewal method of existing revetment or quay as described in any one.   The covering member is a new metal plate, a resin plate, or a concrete plate, and an anchor is installed on the front surface of the ground improvement body, and the covering member is fixed to the front surface of the ground improvement body by the anchor. The renewal method of the existing revetment or quay according to any one of claims 1 to 3. Revetment or quay structure,
Ground improvement body,
An anchor installed directly on the water surface side of the ground improvement body,
A covering member that covers the front surface of the ground improvement body with the anchor;
A filler filled between the covering member and the ground improvement body;
A revetment or quay structure characterized by comprising:

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