JP5147361B2 - Repair and reinforcement structure for floating structures - Google Patents

Description

  The present invention relates to a reinforcing structure for a floating structure such as a pier constructed in a river or in the sea.

  When building piers such as roads and railways on rivers and seas, it is necessary to drive multiple piles to the underground support layer, build footings on the heads of those piles, and stand piers on the top of the footings. It is common. In this case, the footing is embedded in the water bottom ground.

  By the way, as shown in FIG. 13, the level of the water bottom ground 8 is lowered due to the scouring action by the water flow with time, and the existing footing 11 may be exposed from the water bottom ground 8. In FIG. 13, 10 is a bridge pier and 12 is an existing pile. As for the existing pile 12, the front-end | tip 12a is driven to the underground support layer 7, and the existing footing 11 is supported by the head 12b. The existing pier 10 is erected on the upper part of the existing footing 11.

  As shown in FIG. 13, when the existing footing 11 is exposed from the water bottom ground 8, the supporting force is insufficient, and thus countermeasures are required.

As a conventional countermeasure method, as shown in FIG. 14, an annular underground wall 16 is constructed on the ground 8 around the existing footing 11, and additional concrete is provided between the upper end of the underground wall 16 and the existing footing 11. A so-called “Izutsu method” is known in which it is filled with 17.
Japanese Patent Laid-Open No. 9-143953

  However, since the conventional construction method closes the periphery of the existing footing 11 with the underground wall 16, although it can prevent re-scouring, it may still be insufficient in terms of strength improvement.

  In view of the above circumstances, an object of the present invention is to provide a reinforcing structure for a floating structure that can further increase the proof stress as a countermeasure when a submerged ground is scoured.

In the invention of claim 1, the existing footing is supported by the heads of a plurality of existing piles whose tips are driven to a predetermined position, and the ground around the existing footing is scoured by the influence of water flow. In the reinforcing structure, an annular underground wall is provided in the ground that has been scoured around the existing footing, and an additional footing is added to the outer periphery of the existing footing, and the additional footing is inserted into the annular ground. A solid filler is filled in the space between the existing footing and the additional footing and the ground subjected to the scouring , integrally joined to the upper end of the wall and inside the annular underground wall. And

The invention according to claim 2 is the reinforcing structure for a floating structure according to claim 1 , wherein in the ground directly below the increased footing at least at the outer peripheral lower end portion of the region surrounded by the annular underground wall, A ground improvement part that solidifies and improves the effective range for the horizontal resistance of multiple existing piles is provided, and concrete slabs are placed on the surface layer part of the ground subjected to the scouring in the entire plane area inside the annular underground wall - building, inside said annular diaphragm wall, the space between the existing footing and increases footing with the concrete slab, characterized in that filling the in packed material.

In the invention of claim 3 , the existing footing is supported by the heads of a plurality of existing piles whose tips are driven to a predetermined position, and the ground around the existing footing is scoured by the influence of water flow. In the reinforcing structure, an annular underground wall is provided in the ground subjected to scouring around the existing footing, and the ground subjected to the scouring around the existing pile inside the annular underground wall An additional pile whose tip reaches a predetermined position is constructed, an additional footing is added to the outer periphery of the existing footing, and the additional footing is integrally coupled to the upper end of the annular underground wall and the head of the additional pile. In addition , an inside filling material is filled in a space between the existing footing and additional footing and the ground subjected to the scouring inside the annular underground wall .

The invention of claim 4 is the structure for reinforcing a floating structure according to claim 3 , wherein at least the lower end of the outer periphery of the region surrounded by the annular underground wall is in the ground immediately below the increased footing. A ground improvement part that solidifies and improves the effective range for the horizontal resistance of multiple existing piles is provided, and concrete slabs are placed on the surface layer part of the ground subjected to the scouring in the entire plane area inside the annular underground wall - building, inside said annular diaphragm wall, the space between the existing footing and increases footing with the concrete slab, characterized in that filling the in packed material.

According to the invention of claim 1, an annular underground wall is provided in the ground subjected to scouring around the existing footing, an additional footing is added to the outer peripheral portion of the existing footing, and the additional footing is inserted into the annular ground. above attached integrally to the upper end of the wall, further, inside the annular diaphragm wall, the space between the ground who received scouring the existing footing and increased footing, so filled with a medium filling material, the inertial force While suppressing the increase in the maximum possible, it is possible to increase the rigidity of the underground wall above the design ground surface, and to further increase the proof stress. Further, since the existing footing is surrounded by the underground wall and the additional footing, re-scouring can be prevented.

According to the invention of claim 2, an annular underground wall is provided in the ground that has been scoured around the existing footing, an additional footing is added to the outer periphery of the existing footing, and the additional footing is inserted into the annular ground. Combined with the upper end of the wall, and further solidified the effective range for the horizontal resistance of multiple existing piles in the ground just below the increased footing at the lower end of the outer periphery of the area surrounded by the annular underground wall An improved ground improvement section was installed, and concrete slabs were placed and constructed on the surface layer of the ground that had been scoured in the entire area inside the annular underground wall, and the existing footing was placed inside the annular underground wall. and since the filling medium packed material in the space between the increasing footings and concrete slabs, by providing the ground improvement unit, the provision of the concrete slab, expect a synergistic effect due to the filling medium wadding child Can be, it is possible to achieve a more enhanced strength. Further, since the existing footing is surrounded by the underground wall and the additional footing, re-scouring can be prevented.

According to invention of Claim 3 , while providing an annular underground wall in the ground which received the scouring around the existing footing, the ground which received the scouring around the existing pile inside the annular underground wall An additional pile with the tip reaching the specified position is constructed, and an additional footing is added to the outer periphery of the existing footing, and the additional footing is integrally joined to the upper end of the annular underground wall and the head of the additional pile. further, inside the annular diaphragm wall, the space between the ground which receives the scouring and existing footing and increased footing, so filled with a medium filling material, while suppressing as much as possible the increase in inertial force, the design ground The rigidity of the underground wall above the surface can be increased, and the proof stress can be further increased. Further, since the existing footing is surrounded by the underground wall and the additional footing, re-scouring can be prevented.

According to invention of Claim 4 , while providing an annular underground wall in the ground which received the scouring around the existing footing, the ground which received the scouring around the existing pile inside the annular underground wall An additional pile with the tip reaching the specified position is constructed, and an additional footing is added to the outer periphery of the existing footing, and the additional footing is integrally joined to the upper end of the annular underground wall and the head of the additional pile. In addition, a ground improvement part that solidifies and improves the effective range for the horizontal resistance of multiple existing piles is provided in the ground just below the additional footing at the lower end of the outer periphery of the area surrounded by the annular underground wall, A concrete slab is placed and constructed on the surface layer of the ground that has been scoured in the entire area inside the underground wall of the ground, and between the existing footing and the additional footing and the concrete slab inside the annular underground wall. filled with a medium-packed material in the space of Because, by providing the ground improvement unit, the provision of the concrete slab, it is possible to expect a synergistic effect due to the filling medium wadding, it is possible to more enhance the strength. Further, since the existing footing is surrounded by the underground wall and the additional footing, re-scouring can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a reinforcing structure for a floating structure according to the first embodiment.

  The reinforcing structure of the first embodiment is applied to a bridge pier (a floating structure) 10 provided at a portion where a road or a railway crosses the river 6.

  In the structure before reinforcement, as shown in FIG. 13, the existing footing 11 is supported by the heads 12 b of the plurality of existing piles 12 whose tips 12 a reach the underground support layer 7, and the existing footing 11 is provided above the existing footing 11. The pier 10 is erected. Then, the ground 8 around the existing footing 11 has undergone scouring 9 and the riverbed has been lowered, so that the existing footing 11 has been exposed from the bottom bottom ground 8.

  The reinforcing structure of the embodiment shown in FIG. 1 is reinforced, and in this reinforcing structure, an annular underground wall 20 is provided in the ground 8 that has received the scour 9 around the existing footing 11, An additional footing 21 is added to the outer periphery of the existing footing 11, and the additional footing 21 is integrally coupled to the upper end of the annular underground wall 20.

  Here, the annular underground wall 20 is formed of, for example, a square cylindrical steel sheet pile wall, and the lower end is buried to a depth within a range effective for the horizontal resistance of the plurality of existing piles 12. By constructing the additional footing 21 so as to include the upper end of the underground wall 20, the additional footing 21 and the upper end of the underground wall 20 are joined and integrated by a predetermined means.

  According to this reinforcing structure, the proof stress can be enhanced with a simple structure without cost. Further, since the additional footing 21 and the annular underground wall 20 surround the existing footing 11, re-scouring can be prevented. Moreover, the increase of an inertia force can be suppressed by leaving the space between the existing footing 11 and the additional footing 21 and the surface of the design ground 8 in a hollow state (a state where water exists freely).

Second Embodiment
FIG. 2 is a cross-sectional view showing a reinforcing structure for a floating structure according to the second embodiment.

  The reinforcing structure of the second embodiment is light weight in the space between the existing footing 11 and the additional footing 21 and the ground 8 that has received the scouring 9 inside the annular underground wall 20 in the first embodiment. The stuffing material 22 is filled, and other configurations are the same as those in the first embodiment.

  According to this reinforcing structure, since the lightweight intermediate padding material 22 is filled in the space between the existing footing 11 and the additional footing 21 and the ground 8 that has received the scouring 9, while suppressing an increase in inertial force as much as possible, It is possible to increase the rigidity of the underground wall above the design ground level, and to further increase the proof stress. Other functions and effects are the same as in the first embodiment.

<Third Embodiment>
3 is a cross-sectional view showing a reinforcing structure for a floating structure according to a third embodiment, and FIG. 4 is a cross-sectional view taken along the line XX of FIG.

  The reinforcing structure according to the third embodiment includes a plurality of existing piles 12 in the ground 8 immediately below the increased footing 21 at the lower end of the outer periphery of the region surrounded by the annular underground wall 20 in the first embodiment. The ground improvement part 25A which solidified and improved the effective range for horizontal resistance is provided, and the other configuration is the same as that of the first embodiment.

  Here, solidification improvement is performed by injecting a predetermined chemical solution or solidifying material to a depth in a range effective for the horizontal resistance of the plurality of existing piles 12, or by stirring and mixing. The range in which the ground improvement part 25A is provided may be the entire depth inside the underground wall 20 or a partial depth in the depth direction. Moreover, about a horizontal direction, it may be only the outer peripheral part of the area | region enclosed by the underground wall 20, or the whole area | region may be sufficient.

  According to this reinforcing structure, since the ground improvement portion 25A is provided at least at the lower end portion of the annular underground wall 20, the lower end portion of the underground wall 20 can be changed from the free end to the fixed end. Therefore, the rigidity of the underground wall 20 can be increased, and the resistance to driftwood and the like can be increased. Further, if the ground is improved so as to surround the existing pile 12, the rigidity of the existing pile 12 can be increased. Other functions and effects are the same as in the first embodiment.

<Fourth embodiment>
FIG. 5 is a cross-sectional view showing a reinforcing structure for a floating structure according to the fourth embodiment.

  The reinforcing structure of the fourth embodiment is that a concrete slab 25B is placed and constructed in the surface layer portion of the ground 8 that has received the scouring 9 in the entire planar area inside the annular underground wall 20 in the first embodiment. Other configurations are the same as those of the first embodiment.

  As shown in FIG. 5, the concrete slab 25B is constructed by digging the corresponding ground surface first by an amount corresponding to the thickness of the slab 25B, and then placing concrete so that only the dug thickness is refilled later. Alternatively, it may be constructed so as to be stacked on the corresponding ground surface.

  In the former, the level of the ground 8 inside and outside the underground wall 20 can be made uniform, so that it is possible to prevent the underground wall 20 from being subjected to lateral pressure by the concrete slab 25B. In the latter case, it is not necessary to dig down the surface layer portion of the ground 8, so that the work load can be reduced.

  In addition, the concrete slab 25B can also be constructed by performing ground improvement by stirring and mixing instead of the former ground digging.

  According to this reinforcing structure, by providing the concrete slab 25B, the rigidity of the underground wall 20 can be increased, and the resistance to driftwood and the like can be increased. Other functions and effects are the same as in the first embodiment.

<Fifth Embodiment>
FIG. 6 is a cross-sectional view showing a reinforcing structure for a floating structure according to a fifth embodiment.

  The reinforcing structure of the fifth embodiment is a combination of all the features of the first to fourth embodiments. That is, the effective range for the horizontal resistance of the plurality of existing piles 12 is solidified in the ground 8 directly below the increased footing 21 at the lower end of the outer periphery of the region surrounded by the annular underground wall 20 in the first embodiment. An improved ground improvement portion 25A is provided, and a concrete slab 25B is placed and constructed in the surface layer portion of the ground 8 that has undergone scouring 9 in the entire plane area inside the annular underground wall 20, and the annular underground wall 20 The space between the existing footing 11 and the additional footing 21 and the concrete slab 25B is filled with the lightweight filling material 22 inside. Other configurations are the same as those of the first embodiment.

  According to this reinforcing structure, it is possible to expect a synergistic effect due to the provision of the ground improvement portion 25A, the provision of the concrete slab 25B, and the filling of the lightweight filling material, and it is possible to further increase the proof stress. it can. Other functions and effects are the same as those of the first to fourth embodiments.

<Sixth Embodiment>
FIG. 7 is a cross-sectional view showing a reinforcing structure for a floating structure according to a sixth embodiment.

  The reinforcing structure of the sixth embodiment is the inside of the annular underground wall 20 in the first embodiment, in the ground 8 that has received the scour 9 around the existing pile 12 inside the annular underground wall 20. The extension pile 24 whose tip 24a reaches a predetermined position (support layer 7) is constructed, and the additional footing 21 added to the outer periphery of the existing footing 11 is connected to the upper end of the annular underground wall 20 and the head of the extension pile 24. The other configuration is the same as that of the first embodiment.

  According to this reinforcement structure, since the extension pile 24 is provided around the existing pile 12, the proof stress can be further increased as compared with the structure of the first embodiment. Other functions and effects are the same as in the first embodiment.

<Seventh embodiment>
FIG. 8 is a cross-sectional view showing a reinforcing structure for a floating structure according to a seventh embodiment.

  The reinforcing structure of the seventh embodiment is light in the space between the existing footing 11 and the additional footing 21 and the ground 8 that has received the scouring 9 inside the annular underground wall 20 in the sixth embodiment. The stuffing material 22 is filled, and other configurations are the same as in the sixth embodiment.

  According to this reinforcing structure, since the lightweight intermediate padding material 22 is filled in the space between the existing footing 11 and the additional footing 21 and the ground 8 that has received the scouring 9, while suppressing an increase in inertial force as much as possible, It is possible to increase the rigidity of the underground wall above the design ground level, and to further increase the proof stress. Other functions and effects are the same as in the sixth embodiment.

<Eighth Embodiment>
9 is a cross-sectional view showing a reinforcing structure for a floating structure according to an eighth embodiment, and FIG. 10 is a cross-sectional view taken along the line XX of FIG.

  The reinforcing structure of the eighth embodiment includes a plurality of existing piles 12 and a plurality of existing piles 12 in the ground 8 directly below the increased footing 21 at the lower end of the outer periphery of the region surrounded by the annular underground wall 20 in the sixth embodiment. The ground improvement part 25A which solidified and improved the effective range for the horizontal resistance of the additional pile 24 is provided, and the other configuration is the same as that of the sixth embodiment.

  Here, solidification improvement is performed by injecting a predetermined chemical solution or solidifying material to a depth in a range effective for the horizontal resistance of the plurality of existing piles 12, or by stirring and mixing. The range in which the ground improvement part 25A is provided may be the entire depth inside the underground wall 20 or a partial depth in the depth direction. Moreover, about a horizontal direction, it may be only the outer peripheral part of the area | region enclosed by the underground wall 20, or the whole area | region may be sufficient.

  According to this reinforcing structure, since the ground improvement part 25A is provided at least at the lower end of the annular underground wall 20, the lower end of the underground wall 20 and the lower end of the extension pile 24 are fixed from the free end to the fixed end. Can do. Therefore, the rigidity of the underground wall 20 and the extension pile 24 can be increased, and the resistance force against driftwood or the like can be increased. Further, if the ground is improved so as to surround the existing pile 12, the rigidity of the existing pile 12 can be increased. Other functions and effects are the same as in the sixth embodiment.

<Ninth Embodiment>
FIG. 11: is sectional drawing which shows the reinforcement structure of the water structure of 9th Embodiment.

  The reinforcing structure of the ninth embodiment is constructed by placing and constructing a concrete slab 25B on the surface layer portion of the ground 8 that has received the scouring 9 in the entire planar area inside the annular underground wall 20 in the sixth embodiment. The other configuration is the same as that of the sixth embodiment.

  As shown in FIG. 11, the concrete slab 25B is constructed by digging the corresponding ground surface first by an amount corresponding to the thickness of the slab 25B, and then placing concrete so that only the thickness dug down later is backfilled. Alternatively, it may be constructed so as to be stacked on the corresponding ground surface.

  In the former, the level of the ground 8 inside and outside the underground wall 20 can be made uniform, so that it is possible to prevent the underground wall 20 from being subjected to lateral pressure by the concrete slab 25B. In the latter case, it is not necessary to dig down the surface layer portion of the ground 8, so that the work load can be reduced.

  In addition, instead of the former excavation of the ground, the concrete slab 25B can be constructed by performing ground improvement by a stirring and mixing process.

  According to this reinforcing structure, by providing the concrete slab 25B, the rigidity of the underground wall 20 can be increased, and the resistance to driftwood and the like can be increased. Other functions and effects are the same as in the sixth embodiment.

<Tenth Embodiment>
FIG. 12 is a cross-sectional view showing a reinforcing structure for a floating structure according to the tenth embodiment.

  The reinforcing structure of the tenth embodiment is a combination of all the features of the sixth to ninth embodiments, and other configurations are the same as those of the sixth embodiment. That is, the effective range for the horizontal resistance of the plurality of existing piles 12 is solidified in the ground 8 directly below the increased footing 21 at the lower end of the outer periphery of the region surrounded by the annular underground wall 20 in the sixth embodiment. An improved ground improvement portion 25A is provided, and a concrete slab 25B is placed and constructed in the surface layer portion of the ground 8 that has undergone scouring 9 in the entire plane area inside the annular underground wall 20, and the annular underground wall 20 The space between the existing footing 11 and the additional footing 21 and the concrete slab 25B is filled with the lightweight filling material 22 inside.

  According to this reinforcing structure, it is possible to expect a synergistic effect due to the provision of the ground improvement portion 25A, the provision of the concrete slab 25B, and the filling of the lightweight filling material, and it is possible to further increase the proof stress. it can. Other effects are the same as in the sixth to ninth embodiments.

It is sectional drawing which shows the reinforcement structure of the floating structure of 1st Embodiment of this invention. It is sectional drawing which shows the reinforcement structure of the floating structure of 2nd Embodiment of this invention. Sectional drawing which shows the reinforcement structure of the floating structure of 3rd Embodiment of this invention It is XX arrow sectional drawing of FIG. It is sectional drawing which shows the reinforcement structure of the floating structure of 4th Embodiment of this invention. It is sectional drawing which shows the reinforcement structure of the floating structure of 5th Embodiment of this invention. It is sectional drawing which shows the reinforcement structure of the floating structure of 6th Embodiment of this invention. It is sectional drawing which shows the reinforcement structure of the floating structure of 7th Embodiment of this invention. Sectional drawing which shows the reinforcement structure of the floating structure of 8th Embodiment of this invention It is XX arrow sectional drawing of FIG. It is sectional drawing which shows the reinforcement structure of the floating structure of 9th Embodiment of this invention. It is sectional drawing which shows the reinforcement structure of the floating structure of 10th Embodiment of this invention. It is sectional drawing which shows the state which the problem which should be restored | restored to the conventional water structure. It is sectional drawing which shows the outline | summary of the conventional countermeasure construction method.

Explanation of symbols

6 River 7 Support layer (predetermined position)
8 Underwater ground 10 Existing pier 11 Existing footing 12 Existing pile 12a Tip 12b Head 20 Underground wall 21 Additional footing 22 Light weight filling material (filling material)
24 Additional piles 24a Tip 24b Head 25A Ground improvement part 25B Concrete slab

Claims (4)

In the reinforcement structure of the floating structure where the existing footing is supported by the heads of a plurality of existing piles whose tips have been driven to a predetermined position, and the ground around the existing footing has been scoured by the influence of water flow,
An annular underground wall is provided in the ground subjected to scouring around the existing footing, and an additional footing is added to the outer periphery of the existing footing, and the additional footing is attached to the upper end of the annular underground wall. A floating structure characterized in that a filling material is filled in a space between the existing footing and the additional footing and the ground subjected to the scouring, inside the annular underground wall. Reinforcement structure of things. A structure for reinforcing a water structure according to claim 1,
In the ground directly below the increased footing of at least the outer peripheral lower end of the region surrounded by the annular underground wall , a ground improvement portion that solidifies and improves the effective range for the horizontal resistance of the plurality of existing piles is provided, A concrete slab is placed and constructed on the surface layer of the ground subjected to the scouring in the entire plane area inside the annular underground wall , and the existing footing and the additional footing are disposed inside the annular underground wall. A reinforcing structure for a floating structure, wherein the space between the concrete slabs is filled with the filling material. Tip Te is existing footing is supported on the head of a plurality of existing piles that are driven to the predetermined position, the reinforcing structure odor water structure soil surrounding the existing footing is subjected to scouring by the effect of water flow,
While providing an annular underground wall in the ground subjected to scouring around the existing footing,
In the ground that has undergone scouring around the existing pile inside the annular underground wall, build an additional pile whose tip reaches a predetermined position,
An additional footing is added to the outer periphery of the existing footing, and the additional footing is integrally coupled to the upper end of the annular underground wall and the head of the additional pile, and the existing footing is connected to the inner side of the annular underground wall. A reinforcing structure for a floating structure , wherein a space between the footing and the additional footing and the ground subjected to the scouring is filled with a filling material . A structure for reinforcing a water structure according to claim 3 ,
In the ground directly below the increased footing of at least the outer peripheral lower end of the region surrounded by the annular underground wall , a ground improvement portion that solidifies and improves the effective range for the horizontal resistance of the plurality of existing piles is provided, A concrete slab is placed and constructed on the surface layer of the ground subjected to the scouring in the entire plane area inside the annular underground wall, and the existing footing and the additional footing are disposed inside the annular underground wall. A reinforcing structure for a floating structure , wherein the space between the concrete slabs is filled with the filling material .

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