JP5468052B2 - Gravity structure deepening method and gravity structure - Google Patents

Description

  The present invention relates to a deepening method for a gravitational structure (including gravitational structures such as a quay, a landing site, a seawall, and a breakwater) and a gravitational structure.

  Gravity structures such as gravity mooring berths have been widely used. As shown in FIG. 11, the gravitational structure 10 has a rubble mound 14 built on a foundation ground 12, and a wall body 16 (caisson, L-shaped block, cellular block, block, place) on the rubble mound 14. (Including a wall such as cast concrete and an upright wave-dissipating block), and the back ground 18 is supported by the mound 14 and the wall 16.

  By the way, the existing gravity type structure 10 may need to be deepened to enable mooring of a larger ship. In order to deepen this gravity type structure, a new structure is installed on the offshore side of the existing gravity type structure 10 and the foundation ground 12 is excavated to a required depth, so-called “advance”. It is common to adopt a construction method. In this case, as a new structure on the offshore side of the existing gravitational structure 10, a method using a pile and a sheet pile, a method of providing a jetty, and the like are used. As a seismic reinforcement measure, a method of solidifying the entire rubble mound 14 and further improving the ground on the underlying ground 12 is developed (for example, see Patent Document 1).

JP 2000-248527 A

By the way, the conventional advance construction method shifts the normal line of the structure to the offshore side of the existing gravity structure 10, so that it may not be adopted depending on the port facility due to the restriction of the route. On the other hand, as a method for increasing the depth of the existing gravity type structure 10 without changing the normal line of the structure, a measure to reinforce the gravity type structure 10 by a ground anchor or a measure for reducing the weight of the back ground 18 is taken. There are methods, but these methods are limited by the depth of deepening. Moreover, during the construction period, the use of port facilities was restricted for a long time, and it was difficult to keep construction costs low.
The present invention has been made in view of the above problems, and its object is to increase the depth of an existing gravity structure without changing the normal of the structure, although the construction period is shorter than that of the conventional structure. It is to be able to plan.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

(1) A deepening method for a gravitational structure in which a rubble mound is constructed on a foundation ground, a wall body is installed on the rubble mound, and a back ground is supported by the rubble mound and the wall body,
A range of a predetermined depth including the contact surface with the wall body of the rubble mound is partially solidified to be an improved body, and in a plan view, at the same position as the offshore wall surface of the wall body or on the offshore side thereof A deepening method for a gravitational structure in which the rubble mound is removed and a deepening portion is formed in the rubble mound, leaving the improved body located immediately below the wall at the position (Claim 1).

Gravity structure deepening method described in this section is a gravitational structure where a rubble mound is constructed on the foundation ground, a wall body is installed on the rubble mound, and the back ground is supported by the rubble mound and the wall body. It is intended to increase the depth. And the range of the predetermined depth including the contact | adherence surface with a wall body of a rubble mound is partially solidified and made into an improved body, and the support strength of the wall body by a rubble mound is raised with this improved body. At this time, instead of using the entire rubble mound as an improved body, the improved body is partially formed in consideration of the necessary bearing strength.
And, in plan view, at the same position as the offshore wall surface of the wall body or at a position offshore from it, leaving the improved body located directly under the wall body and removing the rubble mound, The wall is supported by the improvement body located. And, by forming the deepening part at the same position as the offshore wall surface of the wall body or the offshore side of the rubble mound, the necessary strength is maintained by the improved body remaining on the rubble mound after the deepening. Is. In addition, the predetermined depth which forms an improved body turns into the depth which can ensure required support strength.

(2) In the above item (1), when the range of a predetermined depth including the contact surface with the wall body of the rubble mound is partially solidified to be an improved body, the solidification injected into the rubble mound As materials, cement-type grout materials, underwater inseparable mortars, pre-packed mortars, cement bentonites, ultrafine particulate special slag, etc., and gravity type structures that are used in appropriate combinations Deepening method.
The deepening method for gravity type structures described in this section includes cemented grout material, underwater inseparable mortar, prepacked mortar, cement bentonite, By using a chemical type injection material such as fine particle-type special slag and the like and appropriately combining them, the cost required for the process is prevented from rising. Moreover, the cost of the process is prevented from rising by partially forming the improved body in consideration of the required bearing strength instead of the entire rubble mound.

(3) In the above paragraphs (1) and (2), an increase in the gravity-type structure in which the improved body is formed in a predetermined range near the center in the thickness direction from the offshore wall surface of the wall body in plan view. Deep construction method (Claim 2).
The deepening method of the gravity type structure described in this section is based on the rubble mound by forming the improved body in a predetermined range near the center in the thickness direction from the offshore wall surface of the wall body in plan view. This increases the bearing strength of the wall. And after forming a deepening part by removing a rubble mound in the same position as the offshore wall surface of a wall body or a position on the offshore side, a required bearing strength is maintained. Therefore, the predetermined range in which the improved body is formed is a range in which necessary support strength can be secured (the same applies hereinafter).

(4) The deepening method of the gravity type structure according to (3) above, wherein the improved body is formed in a predetermined range on the offshore side of the offshore wall surface of the wall body in plan view (claim 3).
The deepening method of the gravity type structure described in this section is to stabilize the wall body by forming the improved body so as to cover a predetermined range on the offshore side of the wall body in plan view. This ensures the support strength necessary for support. In the case of the method according to this section, the deepened portion is formed by partially removing the improved body itself formed on the rubble mound.

(5) In the above items (1) to (4), the improved body is formed in a predetermined range near the center in the thickness direction from the land side wall surface of the wall body in plan view. Deepening method (Claim 4).
The deepening method of the gravity type structure described in this section is based on a rubble mound by forming the improved body in a predetermined range near the center in the thickness direction from the land side wall surface of the wall body in plan view. This increases the bearing strength of the wall.

(6) A deepening method for a gravity type structure according to (5) above, wherein the improved body is formed in a predetermined range on the land side of the land side wall surface of the wall body in plan view (claim 5).
The deepening method of the gravity type structure described in this section is to stabilize the wall body by forming the improved body so as to reach a predetermined range on the land side rather than the land side wall surface of the wall body in plan view. This ensures the support strength necessary for support.

  (7) A rubble mound is constructed on the foundation ground, a wall is installed on the rubble mound, a back ground is supported by the rubble mound and the wall, and the rubble mound is in contact with the wall. A range of a predetermined depth including a partially solidified improvement body, and is located immediately below the wall body at the same position as the offshore wall surface of the wall body or at a position offshore from the wall surface in plan view. A gravitational structure in which the rubble mound is removed and a deepening portion is formed in the rubble mound, leaving the improved body to be formed (Claim 6).

The gravitational structure described in this section is a gravitational structure in which a rubble mound is constructed on a foundation ground, a wall is installed on the rubble mound, and a back ground is supported by the rubble mound and the wall. In the rubble mound, the support strength of the wall body by the rubble mound is enhanced because the range of the predetermined depth including the contact surface with the wall body is made of the partially solidified improved body. Moreover, the entire rubble mound is not an improved body, but an improved body is partially formed in consideration of the necessary bearing strength.
Then, in plan view, the rubble mound is removed at the same position as the offshore wall surface of the wall body or at a position offshore from it, the rubble mound is removed, and the deepening portion is present in the rubble mound. Since it is formed, the necessary strength is maintained by the improved body remaining in the rubble mound even after deepening. Therefore, the predetermined depth at which the improved body is formed is a depth at which necessary support strength can be secured.

(8) In the above item (7), the solidification injected into the rubble mound for partially solidifying the range of the predetermined depth including the contact surface of the rubble mound with the wall body into an improved body As a material, cement type grout material, underwater inseparable mortar, pre-packed mortar, cement bentonite, ultrafine particle type special slag and other chemical type injection materials, etc., and gravitational structure used in combination of these appropriately object.
The gravity type structure described in this section is a cemented grout material, underwater non-separable mortar, prepacked mortar, cement bentonite, ultrafine particulate special slag. By using these chemical liquid type injection materials and the like in appropriate combination, it is possible to prevent the cost required for the process from rising. Moreover, the cost of the cost for forming the improved body is prevented by forming the improved body partially in consideration of the required bearing strength, not the entire rubble mound.

(9) In the above items (7) and (8), the improved body is a gravity structure formed in a predetermined range near at least the central part in the thickness direction from the offshore wall surface of the wall body in plan view. (Claim 7).
In the gravity structure described in this section, the improved body is formed in a predetermined range near the central portion in the thickness direction from the offshore wall surface of the wall body in a plan view. The bearing strength of is increased. And even after the deepening part is formed by removing the rubble mound at the same position as the offshore wall surface of the wall body or a position on the offshore side, the necessary bearing strength is maintained. . Therefore, the predetermined range in which the improved body is formed is a range in which the necessary supporting strength can be secured (the same applies hereinafter).

(10) In the above item (9), the improved body is a gravitational structure formed in a predetermined range on the offshore side than the offshore wall surface of the wall body in a plan view (claim 8).
In the gravity structure described in this section, the improved body is formed so as to cover a predetermined range on the offshore side rather than the offshore wall surface of the wall body in a plan view. Necessary supporting strength is ensured. In the case of the method according to this item, the deepened portion is formed by partially removing the improved body formed on the rubble mound.

(11) In the above items (7) to (10), the improved body is formed in a predetermined range near at least a central portion in the thickness direction from the land side wall surface of the wall body in plan view. (Claim 9).
The gravity structure described in this section is such that the improved body is formed in a predetermined range near the center in the thickness direction from the land side wall surface of the wall body in plan view, so that the wall body by the rubble mound The support strength of can be increased.

(12) In the above item (11), the improved body is a gravitational structure formed in a predetermined range on the land side with respect to the land side wall surface of the wall body in plan view (claim 10).
In the gravity structure described in this section, the improved body is formed so as to reach a predetermined range on the land side rather than the land side wall surface of the wall body in a plan view. Necessary supporting strength is ensured.

  Since this invention was comprised in this way, it becomes possible to aim at deepening from the existing gravity type structure, without changing the normal line of a structure, although it is a construction period shorter than before.

It is sectional drawing which shows typically the gravity type structure obtained by the deepening method of the gravity type structure which concerns on embodiment of this invention, (a)-(d) shows the example of a specific structure It is. It is a flowchart of the deepening method of the gravity type structure which concerns on embodiment of this invention. It is a schematic cross section which shows the leakage prevention measure process at the time of the mound improvement of the deepening method of the gravity type structure which concerns on embodiment of this invention shown by FIG. 2, (a)-(c) A specific example is shown. FIG. 3 is a schematic cross-sectional view illustrating an installation process of a deepening method for a gravity type structure according to the embodiment of the present invention shown in FIG. Shows a specific example. FIG. 3 is a schematic cross-sectional view showing a step of drilling a hole, injecting an injection pipe, and injecting a solidifying material in the deepening method of the gravity type structure according to the embodiment of the present invention shown in FIG. (c) shows a specific example, and (b) and (d) are enlarged views of main parts of (a) and (c). FIG. 3 is a schematic cross-sectional view showing another specific example of drilling, erection of an injection pipe, and a solidifying material injection process of the deepening method of the gravity type structure according to the embodiment of the present invention shown in FIG. (A) is sectional drawing (b) is a top view. FIG. 3 is a schematic cross-sectional view showing another specific example of drilling, erection of an injection pipe, and a solidifying material injection process of the deepening method of the gravity type structure according to the embodiment of the present invention shown in FIG. (A) is sectional drawing (b) is a top view. FIG. 3 is a schematic cross-sectional view showing another example of drilling, injection pipe erection, and solidification material injection step of the deepening method of the gravity type structure according to the embodiment of the present invention shown in FIG. ) Is a sectional view (b) is a plan view. It is a schematic cross section which shows the solidification material injection | pouring process of the deepening method of the gravity type structure which concerns on embodiment of this invention shown by FIG. It is a schematic cross section which shows the deepening part excavation process of the deepening method of the gravity type structure which concerns on embodiment of this invention shown by FIG. 2, (a), (b) shows the specific example. Is. It is sectional drawing which shows the conventional gravity type structure typically.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Here, parts that are the same as or correspond to those in the prior art are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 1 shows an example of the structure of a gravitational structure according to an embodiment of the present invention. Each of these gravitational structures has a rubble mound 14 built on the foundation ground 12 (see FIG. 11), a wall body 16 is installed on the rubble mound 14, and the mound 14 and the wall body 16 are behind. The ground 18 (see FIG. 11) is supported.

Furthermore, as a characteristic part in the embodiment of the present invention, a range of a predetermined depth including a contact surface of the rubble mound 14 with the wall body 16 is partially solidified to be an improved body 22. Then, in plan view, at the same position as the offshore wall surface 16 a of the wall body 16, the rubble mound 14 is removed, leaving the improved body 22 positioned immediately below the wall body 16, and the deepening portion 14 d is formed on the rubble mound 14 Formed. 1A to 1D, the improved body 22 is at least a predetermined range (structure) near the central portion in the thickness direction from the offshore wall surface 16a of the wall body 16 in plan view. In the range where necessary proof stress can be obtained).

  A gravity structure 10A shown in FIG. 1A is obtained by forming an improved body 22A in a predetermined range further on the offshore side than the offshore wall surface 16a of the wall body 16 in a plan view. In the illustrated example, the improved body 22A is formed in a range that covers the deepened portion 14d of the rubble mound 14. Further, the improved body 22 </ b> A is formed in a range from the lower surface 16 c of the wall body 16 to the upper surface 12 a of the foundation ground 12 as a predetermined depth range including the contact surface with the wall body 16.

  Also in the gravitational structure 10B shown in FIG. 1B, the improved body 22B is formed in a predetermined range further offshore than the offshore wall surface 16a of the wall body 16 in plan view. And the improvement body 22B is formed in the range which covers the deepening part 14d of the rubble mound 14. FIG. Further, the improved body 22B is formed in a range from the lower surface 16c of the wall body 16 to the upper surface 12a of the foundation ground 12 up to an intermediate depth as a range of a predetermined depth including a contact surface with the wall body 16.

  On the other hand, the gravitational structure 10C shown in FIG. 1C is obtained by forming the improved body 22C so as to fit in the same position as the offshore wall surface 16a of the wall body 16 in plan view. Further, the improved body 22 </ b> C is formed in a range from the lower surface 16 c of the wall body 16 to the upper surface 12 a of the foundation ground 12 as a predetermined depth range including a contact surface with the wall body 16.

  On the other hand, also in the gravity structure 10D shown in FIG. 1D, the improved body 22D is formed so as to fit in the same position as the offshore wall surface 16a of the wall body 16 in plan view. And the improvement body 22D is formed in the range from the lower surface 16c of the wall body 16 to the upper surface 12a of the foundation ground 12 to the intermediate depth as a range of the predetermined depth including the contact surface with the wall body 16.

  In addition, although illustration is abbreviate | omitted, also in any structural example of Fig.1 (a)-(d), the improvement body 22 is near center part of the thickness direction from the land side wall surface 16b of the wall body 16 by planar view. It is good also as forming in the predetermined range of this, and it is good also as forming in the predetermined range of the land side rather than the land side wall surface 16b of the wall body 16 by planar view. Specifically, the improved bodies 22A to 22D shown in FIGS. 1A to 1D may be formed symmetrically with respect to the central portion of the wall body 16 in the thickness direction.

Then, each process S100-S200 of the deepening method of the gravity type structure which concerns on embodiment of this invention is demonstrated, referring FIGS. 2-10.
(S100) Investigation within the rubble: The formation range and necessity of the improved body 22 for investigating the state in the rubble mound 14 of the existing gravitational structure 10 and obtaining the desired support strength of the wall 16 by the rubble mound 14 Determine strength, etc.
(S110) Washing in rubble: Removal of surface deposits and organisms such as algae from the rubble mound 14 is carried out by washing with a water jet, sucking with an air lift pump, pump culvert and the like.
(S120) Leakage prevention measures: In order to prevent leakage of the solidified material, which will be described later, from the rubble mound 14, a leakage prevention measure is taken on the surface of the rubble mound 14. As a specific example, as shown in FIG. 3A, a water shielding sheet 24 is laid on the surface of the rubble mound 14 and covered with a presser stone 26 to fix the water shielding sheet 24 to the surface of the rubble mound 14. To do. Alternatively, rubble, crushed stone, or the like may be used as the presser stone without using the water shielding sheet 24. Further, as shown in FIG. 3B, a cloth formwork is installed on the surface of the rubble mound 14, concrete is filled in the cloth formwork, and the surface of the rubble mound 14 is covered with a concrete layer 28. Alternatively, as shown in FIG. 3 (c), the solidified layer 30 is formed on the surface portion of the rubble mound 14 by filling the surface of the rubble mound 14 with an instantaneous setting agent or asphalt mastic, etc. Is mentioned.

(S130) Installation of SEP trolley, installation of overhanging scaffolding, etc .: As shown in FIG. 4 (a), SEP (self-lifting) pontoon 32 is docked on the gravitational structure 10, or FIG. The overhanging scaffolding 34 is installed as shown in FIG.
(S140) Drilling machine installation: As shown in FIGS. 4 (a) and 4 (b), required for drilling machine 36 (shown only in FIG. 4) and other drilling on SEP carriage 32 or overhanging scaffold 34 Install appropriate equipment.

(S150) Drilling: As shown in FIGS. 4 (a) and 4 (b), using a rotary type, rotary percussion type or down-the-hole hammer of the drilling machine 36, the wall of the rubble mound 14 in plan view A single row or a plurality of rows of holes are drilled along the longitudinal direction of the wall 16 in a predetermined range immediately below 16 and a predetermined range on the offshore side of the offshore wall surface 16a. At this time, as the drilling depth increases, drilling is performed to a predetermined depth while adding the drilling casing 38. In addition, when it is difficult to improve the ground only by construction from the sea side, as shown in FIG. 4 (c), as shown in FIG. Sometimes holes are made.
(S160) Construction of injection pipe: As shown in FIGS. 5 (c) and 5 (d), an outer pipe 40 for injection for injecting solidified material into the rubble mound 14 is built using the casing 38 for drilling as a guide. Include. After completion of the construction of the outer pipe 40 for injection, the casing 38 for drilling is pulled out from the rubble mound 14.

(S170) Solidification material injection: The solidification material 46 (for convenience in FIG. 9) is used in the rubble mound 14 using the double tube in which the injection inner tube 42 is inserted inside the injection outer tube 40 and the packer 44. Injected with arrows. And the improvement body 22 is formed in the predetermined range near the center part of the thickness direction from the offshore side wall surface 16a of the wall body 16 by planar view. Furthermore, it forms in the predetermined range of the offshore side rather than the offshore wall surface 16a of the wall body 16 as needed.
At this time, as shown in FIGS. 6 (a) and 6 (b), the primary injection outer tube 401 for filling the large gap and the small gap for filling according to the gap situation of the rubble mound 14 It is also possible to adopt a technique in which the improved body 221 filled with the large gap is formed after the secondary injection outer tube 402 is alternately built, and then the improved body 22 filled with the small gap is formed. Further, as shown in FIGS. 7 (a) and 7 (b), the outer tube 400 for injection of instantaneous setting injection material is placed on the offshore side of the outer tube 401 for primary injection and the outer tube 402 for secondary injection. The offshore side wall 220 is formed in the offshore boundary portion in the range where the improved body 22 is formed by filling the instantaneously injecting material 400 from the outer tube 400 for injection of the instantaneously injectable material. Thereafter, as in FIGS. 6A and 6B, it is also possible to adopt a method of forming the improved body 222 filled with a small gap after forming the improved body 221 filled with a large gap. Further, as shown in FIGS. 8 (a) and 8 (b), the offshore side boundary portion of the range in which the instantly injecting material is filled from the outer tube 400 for injecting instantly injectable material to form the improved body 22. The improved bodies 221 and 222 may be formed after the offshore wall 220 and the bottom board 220 ′ are formed at the bottom boundary portion.
In addition, the solidification material 46 used here is suitably selected according to the condition of the rubble which comprises the rubble mound 14, for example, cement-type grout material, underwater non-separable mortar, prepacked mortar, cement Examples include bentonite, chemical type injection materials such as ultrafine particle special slag, and the like, and appropriate combinations thereof.
(S180) Removal of drilling machine, etc .: The drilling machine 36 (shown only in FIG. 4) and other equipment necessary for drilling are removed from the SEP carriage 32 or the overhanging scaffold 34. In addition, when it forms in the predetermined range of the land side rather than the land side wall surface 16b of the wall body 16 by planar view, the process of said S140-S180 is also performed from the land side wall surface 16b of the wall body 16. FIG.

(S190) Removal of SEP carrier / overhanging scaffold: The SEP carrier 32 or the overhanging scaffold 34 is removed from the gravity structure 10.
(S200) Deepening excavation: As shown in FIG. 10, in the plan view, at the same position as the offshore wall surface 16a of the wall body 16 or at an offshore side, an improvement located directly below the wall body 16 The rubble mound 14 (and a part of the improved body 22 if necessary) is removed, leaving the body 22, and a deepening portion 14 d is formed in the rubble mound 14. In this step, for example, the rubbing mound 14 is excavated using a gut ship 48 as shown in FIG. 10 (a) or using an underwater backhoe 50 as shown in FIG. 10 (b). In addition, depending on the situation, human-powered excavation by divers, excavation by a telescopic clamshell, excavation by an all-round rotating all casing, etc. are also carried out. Then, accumulation of rubble by a diver and removal of rubble by a gut ship 48 are performed. Thus, the deepening of the gravitational structure 10 is completed.

Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained. That is, in the embodiment of the present invention, the gravel type mound 14 is constructed on the foundation ground 12, the wall body 16 is installed on the rubble mound 14, and the back ground 18 is supported by the rubble mound 14 and the wall body 16. The deepening of the structure 10 is performed. And the range of the predetermined depth including the contact | adherence surface with the wall body 16 of the rubble mound 14 is partially solidified into the improved body 22, and the support strength of the wall body 16 by the rubble mound 14 is improved by this improved body 22. It is something to enhance. In addition, at this time, the entire rubble mound 14 is not used as an improved body, but the improved body 22 is partially formed in consideration of the necessary support strength.

Then, in plan view, at the same position as the offshore wall surface 16a of the wall body 16 or at a position on the offshore side, the improved body 22 located immediately below the wall body 16 is left and the rubble mound 14 is removed. Thus, the wall body 16 can be supported by the improved body 22 located immediately below the wall body 16. And by forming the deepening part 14d in the same position as the offshore side wall surface 16a of the wall body 16 of the rubble mound 14 or a position on the offshore side thereof, the improved body 22 remaining on the rubble mound 14 after the deepening, It becomes possible to maintain the required yield strength.

  In addition, the solidified material 46 for solidifying the rubble mound 14 to improve it is a chemical type injection material such as cement grout material, underwater separable mortar, prepacked mortar, cement bentonite, ultra fine particle special slag, etc. By using these in combination, it is possible to prevent an increase in cost required for the process. Moreover, it is possible to prevent an increase in the cost required for the process by forming the improved body 22 partially in consideration of the necessary bearing strength, not the entire rubble mound 14.

Further, by forming the improved body 22 in a predetermined range at least from the offshore wall surface 16a of the wall body 16 in the thickness direction in the plan view, the support strength of the wall body 16 by the rubble mound 14 is increased. Yes. And, even after the deepening portion 14d is formed by removing the rubble mound 14 at the same position as the offshore wall surface 16a of the wall body 16a or at a position offshore thereof, the necessary supporting strength is maintained. It is.
Further, by forming the improved body 22 so as to reach a predetermined range on the offshore side than the offshore wall surface 16a of the wall body 16 in plan view, the support strength necessary for stable support of the wall body 16 is ensured. Is.

Further, by forming the improved body 22 in a predetermined range near the center in the thickness direction from the land side wall surface 16b of the wall body 16 in plan view, the support strength of the wall body 16 by the rubble mound may be increased. It becomes possible.
Furthermore, the improved body 22 is formed so as to extend over a predetermined range on the land side of the wall 16 than the land side wall surface 16b of the wall 16 in plan view, thereby ensuring the supporting strength necessary for stable support of the wall 16. It becomes possible.

And according to embodiment of this invention, it becomes possible to give the deepening of 2 m or more with respect to the existing gravity type structure 10. FIG. Further, the earthquake resistance is not deteriorated due to the deepening, and the wave resistance can be maintained as before the deepening.
For the deepening and seismic reinforcement of the gravitational structure 10, the improved body 22 may be formed at least in a predetermined range near the central portion in the thickness direction from the offshore wall surface 16a of the wall body 16 in plan view. It is effective. Further, in order to improve the wave resistance performance of the gravitational structure 10, the improved body 22 is further formed in a predetermined range near the center in the thickness direction from the land side wall surface 16b of the wall body 16 in plan view. Is desirable.

  10, 10A, 10B, 10C, 10D: Gravity structure, 12: Foundation ground, 14: Rubble mound, 14d: Deepening part, 16: Wall body, 16a: Offshore wall surface, 16b: Landside wall surface, 18: Back Ground, 22, 220, 220 ', 221, 222, 22A, 22B, 22C, 22D: improved body, 46: solidified material

Claims (10)

Constructing a rubble mound on the foundation ground, installing a wall body on the rubble mound, and a deepening method of a gravity type structure supporting a back ground by the rubble mound and the wall body,
A range of a predetermined depth including the contact surface with the wall body of the rubble mound is partially solidified to be an improved body,
In plan view, at the same position as the offshore wall surface of the wall body or at a position offshore from it, leaving the improved body located directly below the wall body, removing the rubble mound, and to the rubble mound Gravity structure deepening method characterized by forming deepening part. The deepening method for a gravitational structure according to claim 1, wherein the improved body is formed in a predetermined range at least near the central portion in the thickness direction from the offshore wall surface of the wall body in plan view. The method of deepening a gravity type structure according to claim 2, wherein the improved body is formed in a predetermined range on the offshore side of the wall surface of the wall body in plan view. The gravity type according to any one of claims 1 to 3, wherein the improved body is formed in a predetermined range near a central portion in a thickness direction from a land side wall surface of the wall body in a plan view. Structure deepening method. The deepening method for a gravitational structure according to claim 4, wherein the improved body is formed in a predetermined range on a land side of a land side wall surface of the wall body in plan view. A rubble mound is constructed on the foundation ground, a wall is installed on the rubble mound, and the back ground is supported by the rubble mound and the wall,
The rubble mound is composed of an improved body in which a range of a predetermined depth including a contact surface with the wall body is partially solidified,
In plan view, at the same position as the offshore wall surface of the wall body or at a position offshore from the wall body, leaving the improved body located directly under the wall body, the rubble mound is removed, and the rubble mound is Gravity structure characterized in that deepening part is formed. The gravitational structure according to claim 6, wherein the improved body is formed in a predetermined range at least near the center in the thickness direction from the offshore wall surface of the wall body in plan view. 8. The gravity structure according to claim 7, wherein the improved body is formed in a predetermined range on the offshore side of the wall surface of the wall body in plan view. The said improvement body is formed in the predetermined range near the center part of the thickness direction from the land side wall surface of the said wall body by planar view, The any one of Claim 6 to 8 characterized by the above-mentioned. Gravity structure. The gravity structure according to claim 9, wherein the improved body is formed in a predetermined range on a land side with respect to a land side wall surface of the wall body in a plan view.

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