JP6842890B2 - How to build a mountain retaining and underground structure - Google Patents

Description

The present invention relates to a mountain retainer and a method for constructing an underground structure using the mountain retainer.

As a method of constructing a new underground structure, for example, an all-casing method (CD method) is used to remove underground obstacles, a pile is constructed at the removed part of the underground obstacle, and a new underground structure is constructed inside the pile. The construction method to build is known. However, with this construction method, it is necessary to construct a new retaining wall while removing underground obstacles, which increases the construction cost and the construction period.

In order to solve this problem, for example, Patent Document 1 discloses a construction method of an underground structure in which all the existing underground skeletons (underground outer wall and underground bottom slab) of the existing underground structure are left and used as a mountain retainer.

Japanese Patent No. 3461227

However, when all the existing underground skeletons (underground outer wall and underground bottom slab) are left and used as a mountain retainer, the size of the new underground structure constructed in the mountain retainer will be smaller than the size of the existing underground structure. That is, the size of the newly constructed underground structure cannot be changed freely.

In view of the above facts, the present invention provides a method for constructing an underground structure and a pile retaining structure in which the construction cost can be reduced, the construction period can be shortened, and the size of the newly constructed underground structure can be freely changed. The purpose is.

The retaining wall according to the first aspect was provided and removed from the existing underground skeleton in which at least a part of the underground outer wall or the underground bottom slab was removed and a part was left, and the inside or outside of the remaining existing underground skeleton. It has an underground outer wall or a new retaining wall that receives earth pressure acting on the portion where the underground bottom slab was present.

According to the above configuration, by constructing a mountain retaining wall with the remaining existing underground skeleton and the new retaining wall, the size of the new underground structure can be reduced as compared with the case where all the existing underground skeleton is left as a mountain retaining wall. You can change it freely. In addition, the construction cost can be reduced and the construction period can be shortened as compared with the case where the retaining wall is constructed only with the newly constructed retaining wall.

The earth pressure according to the second aspect is the earth pressure according to the first aspect, the existing underground skeleton is two existing underground skeletons from which the facing underground outer walls are removed, and the new underground skeleton is the two. It is provided along the underground outer wall where the existing underground skeleton remains, and receives earth pressure acting on the portion sandwiched between the removed underground outer walls.

According to the above configuration, the two existing underground skeletons are made into one by removing the facing underground outer walls of the two existing underground skeletons and providing a new retaining wall along the remaining underground outer walls of the two existing underground skeletons. It can be used as a single clasp, and one large new underground structure can be constructed within the clasp.

The method for constructing the underground structure according to the third aspect is a step of constructing a new retaining wall outside a part of the underground outer wall to be removed, and removing the part of the underground outer wall and leaving the other underground outer wall. It has a step of removing an existing underground structure and a step of constructing a new underground structure inside the new retaining wall and the underground outer wall.

According to the above configuration, the remaining underground outer wall and the new retaining wall can be used as a retaining wall when constructing a new underground structure. For this reason, the size of the newly constructed underground structure can be freely changed as compared with the case where all the existing underground outer walls are left as a mountain retaining wall. In addition, the construction cost can be reduced and the construction period can be shortened as compared with the case where the retaining wall is constructed only with the newly constructed retaining wall.

According to the present invention, the construction cost can be reduced, the construction period can be shortened, and the size of the newly constructed underground structure can be freely changed.

(A) is a plan view showing the retaining structure in the first embodiment, and (B) is a cross-sectional view taken along the line AA. (A) to (C) are plan views showing the procedure for constructing a retaining wall and an underground structure in the second embodiment. (A) is a plan view showing the retaining structure in the third embodiment, and (B) is a cross-sectional view taken along the line BB. It is sectional drawing which shows the mountain retaining in 4th Embodiment.

(First Embodiment)
Hereinafter, the retaining pile according to the first embodiment of the present invention will be described with reference to FIG.

<Structure>
As shown in FIGS. 1A and 1B, the retaining wall 10 of the first embodiment is composed of an underground outer wall 14 of an existing underground skeleton 12 and a new retaining wall 16. The existing underground skeleton 12 defines the underground space M of the existing building, and is made of, for example, a reinforced concrete (RC) structure.

Further, in the existing underground skeleton 12, one surface 14A of the underground outer wall 14 has been dismantled and removed, and the underground outer walls 14B, 14C, 14D of the existing underground skeleton 12 having a U shape in a plan view surrounding three sides and the existing underground skeleton 12 Underground slab 18 and is left. Although not shown, the above-ground structures of existing buildings and existing underground structures such as underground columns and beams have been demolished and removed.

The new retaining wall 16 receives earth pressure acting on the part where the removed one surface 14A of the underground outer wall 14 was present, and is outside the remaining underground outer walls 14B, 14C, 14D, that is, outside the underground space M. It is provided. Further, the new retaining wall 16 is formed by the main pile horizontal sheet pile method as an example.

Specifically, the new retaining wall 16 has a main pile 20 made of a plurality of H-shaped steels built in the ground at regular intervals and a plurality of wooden horizontal sheet piles 22 inserted between the flanges of the main pile. It is composed of and. As shown in FIG. 1 (B), the lower end of the main pile 20 of the new retaining wall 16 is rooted to a position deeper than the underground bottom slab 18.

Further, as shown in FIG. 1A, the newly constructed retaining wall 16 is connected to the ends of the underground outer walls 14B and 14D to which the removed one side 14A was joined, respectively. As a result, the underground space N having a larger area than the underground space M is defined by the newly constructed retaining wall 16 and the underground outer walls 14B, 14C, and 14D.

If the earth pressure acting on the new retaining wall 16 is low and the new retaining wall 16 can stand on its own, or if the groundwater level is deeper than the underground bottom slab 18, the new retaining wall 16 and the underground outer walls 14B and 14D are connected. You don't have to.

On the other hand, when the earth pressure acting on the retaining wall 10 is high, the new retaining wall 16 and the underground outer walls 14B and 14D are connected, and some underground structures such as underground columns and beams of the existing building are not removed. It may be left in the ground or a new girder or the like may be provided. When the groundwater level is shallower than the underground bottom slab 18, the new retaining wall 16 is formed by a ground improvement wall (soil cement wall) having water impermeability, and between the new retaining wall 16 and the underground outer walls 14B and 14D. A chemical solution may be injected to stop water.

<How to build an underground structure>
When constructing a new underground structure 24 using the mountain retainer 10, first, the above-ground structure (not shown) of the existing building is dismantled and removed. Then, a new retaining wall 16 is constructed outside the one side 14A of the underground outer wall 14 of the existing building, that is, outside the underground space M.

Next, while leaving the underground outer walls 14B, 14C, 14D and the underground bottom slab 18 of the existing underground skeleton 12, one side 14A of the underground outer wall 14 of the existing building and other existing underground structures (not shown) are dismantled and removed, and underground. Excavate the ground between one side 14A of the outer wall 14 and the new retaining wall 16.

After that, a new underground structure 24 including a new underground outer wall and a new underground bottom slab is constructed inside the retaining wall 10 composed of the new retaining wall 16 and the underground outer walls 14B, 14C, and 14D, that is, in the underground space N. The above process procedure is an example, and the order may change. Further, after constructing the new underground structure 24, a step of removing the new retaining wall 16 may be provided.

<Action, effect>
According to the present embodiment, since the new underground structure 24 is constructed in the retaining 10 after the retaining 10 is constructed, the earth pressure can be received by the retaining 10. Further, the retaining wall 10 is composed of underground outer walls 14B, 14C, 14D of the existing underground skeleton 12 and new retaining walls 16 provided outside the underground outer walls 14B, 14C, 14D.

For this reason, it is possible to construct a new underground structure 24 having a larger area than the area of the existing underground structure, as compared with the case where all the existing underground skeleton 12 is left as a pile. Further, as compared with the case where the retaining wall 16 is used alone as the retaining wall, the construction cost can be reduced and the construction period can be shortened.

(Second Embodiment)
Next, the retaining pile according to the second embodiment of the present invention will be described with reference to FIG.

<Structure>
In the second embodiment, as shown in FIG. 2A, the existing underground skeletons 30 and 32 of the two existing underground structures 26 and 28 defining the underground spaces P and Q of the two existing buildings are spaced apart from each other. It is provided so that it is open and adjacent to each other. Further, as shown in FIG. 2C, of the two existing underground skeletons 30 and 32, the facing surfaces 34A and 36A of the underground outer walls 34 and 36 have been dismantled and removed, respectively.

On the other hand, the newly constructed retaining wall 38 of the present embodiment receives earth pressure acting on the portion sandwiched between the removed one surfaces 34A and 36A of the underground outer walls 34 and 36, and the remaining underground outer walls 34 and 36 It is provided on the outside, that is, outside the underground spaces P and Q. Further, the newly constructed retaining wall 38 is formed by a ground improvement wall (soil cement wall) as an example.

The ground improvement wall as the new retaining wall 38 is composed of a plurality of ground improvement pillars in which the outer peripheral portions are wrapped around each other and integrated, and the ground improvement pillars include, for example, excavated soil and cement milk while excavating the ground. It is created by mixing and stirring with the solidifying material of. In addition, H-shaped steel or the like (not shown) may be used as the core material of the ground improvement column.

In addition, the new retaining wall 38 is provided along the remaining underground outer walls 34 and 36, and connects the ends of the underground outer walls 34 and 36 to which the removed one surfaces 34A and 36A are joined, respectively. It is provided in. As a result, the retaining wall 38 is constructed by the new retaining wall 38 and the remaining underground outer walls 34 and 36, and the underground space R having a larger area than the underground spaces P and Q is defined.

Further, the water blocking agent 42 is injected into the gap between the newly constructed retaining wall 38 and the ends of the underground outer walls 34 and 36. The water blocking agent 42 is, for example, a water glass grout material, and by being injected into the ground, the water stopping agent of the ground can be enhanced. If the groundwater level is deeper than the underground bottom slabs of the existing underground skeletons 30 and 32 (not shown), it is not necessary to inject the water blocking agent 42 into the gap between the new retaining wall 38 and the ends of the underground outer walls 34 and 36. ..

<How to build an underground structure>
When constructing a new underground structure 44 using the mountain retaining 40, first, the above-ground structures (not shown) of the two existing buildings are dismantled and removed. Then, as shown in FIG. 2 (B), a new retaining wall 38 is provided on the outside of the facing surfaces 34A and 36A of the two existing underground structures 26 and 28, that is, on the outside of the underground spaces P and Q. To build.

Next, the existing columns 46 and the existing beams 48 of the two existing underground structures 26 and 28 are all dismantled and removed, and as shown in FIG. 2C, the underground outer walls 34 and 36 of the existing underground structures 30 and 32 are dismantled and removed. One side 34A and 36A are dismantled and removed. In addition, the ground of the portion surrounded by the one surfaces 34A and 36A of the underground outer walls 34 and 36 and the newly constructed retaining wall 38 will be excavated.

As in the first embodiment, when the earth pressure acting on the retaining wall 40 is high, the existing columns 46 and the existing beams 48 of the existing underground structures 26 and 28 may be left without being partially removed, or newly. A girder or the like may be provided.

After that, a new underground structure 44 including a new underground outer wall and a new underground bottom slab is constructed inside the retaining wall 40 composed of the new retaining wall 38 and the underground outer walls 34 and 36, that is, in the underground space R. The above process procedure is an example, and the order may change.

<Action, effect>
According to the present embodiment, since the new underground structure 44 is constructed in the retaining 40 after the retaining 40 is constructed, earth pressure can be received by the retaining 40 as in the first embodiment.

Further, in the present embodiment, the new retaining wall 38 is formed by the ground improvement wall, and the water blocking agent 42 is injected into the gap between the new retaining wall 38 and the ends of the underground outer walls 34 and 36. Therefore, especially when the groundwater level is shallower than the underground bottom slabs of the existing underground skeletons 30 and 32, the groundwater can be stopped by the new retaining wall 38.

Further, by forming the new retaining wall 38 by the ground improvement wall, the ground can be improved as compared with the case where the new retaining wall 16 is formed by the main pile horizontal sheet pile method as in the first embodiment.

Further, according to the present embodiment, the two existing underground skeletons 30 and 32 are removed from the facing surfaces 34A and 36A of the underground outer walls 34 and 36, respectively, and new underground retaining is carried out along the remaining two underground outer walls 34 and 36. A wall 38 is provided. Therefore, one underground retaining wall 40 can be constructed by the two underground outer walls 34 and 36 and the new retaining wall 38, and one large-scale new underground structure 44 can be constructed in the retaining wall 40. ..

(Third Embodiment)
Next, the retaining pile according to the third embodiment of the present invention will be described with reference to FIG.

<Structure>
As shown in FIG. 3B, the existing underground skeleton 50 of the existing building of the third embodiment is provided at a position deeper than the underground outer wall 52, the first underground slab 54A, and the first underground slab 54A. It has a bottom slab 54B, and an underground space S having a different level (depth) is defined by the existing underground skeleton 50.

Further, as shown in FIGS. 3 (A) and 3 (B), among the existing underground skeletons 50, the two surfaces 52B and 52C facing the underground outer wall 52 adjacent to the one surface 52A and the one surface 52A of the underground outer wall 52, respectively. A part and a part of the first underground slab 54A adjacent to one side 52A have been dismantled and removed, respectively.

Inside the remaining underground outer wall 52, that is, inside the underground space S, a new retaining wall 56 is provided so as to connect the ends of the remaining two surfaces 52B and 52C of the underground outer wall 52. The new retaining wall 56 is subject to earth pressure acting on the part where the removed one side 52A and the two sides 52B and 52C of the underground outer wall 52 existed, and the new retaining wall 56 and the remaining underground outer wall An underground space T having a smaller area than the underground space S is defined along with the construction of the earth retaining wall 60 by the 52.

The new retaining wall 56 is composed of a plurality of steel sheet piles 62 (sheet piles) as an example. Specifically, the steel sheet pile 62 is a shaped steel having a corrugated cross section, and a new retaining wall 56 is constructed by alternately combining a plurality of steel sheet piles 62 and connecting joints (not shown) provided at both ends. .. As shown in FIG. 3B, the lower end of the new retaining wall 56 (steel sheet pile 62) is deeper than the first underground slab 54A and shallower than the second underground slab 54B.

<How to build an underground structure>
When constructing a new underground structure 64 using the retaining wall 60, first, the new retaining wall 56 is constructed inside the one side 54A of the underground outer wall 52 of the existing underground skeleton 50, that is, inside the underground space S.

Next, of the existing underground skeleton 50, one side 52A of the underground outer wall 52, which is a part outside the new retaining wall 56, a part of the two sides 52B and 52C of the underground outer wall 52, and a part of the first underground bottom slab 54A. To be dismantled and removed. When it is not necessary to construct another new structure or the like on the outside of the new retaining wall 56, one side 52A of the underground outer wall 52, a part of the two sides 52B and 52C of the underground outer wall 52, and the first A part of the underground slab 54A may be left without being removed.

After that, a new underground structure 64 including a new underground outer wall and a new underground bottom slab is constructed inside the mountain retaining 60 composed of the new retaining wall 56 and the remaining underground outer wall 52, that is, in the underground space T. The above process procedure is an example, and the order may change. Further, after constructing the new underground structure 64, a step of removing the new retaining wall 56 may be provided.

<Action, effect>
According to the present embodiment, a new retaining wall 56 is provided inside the one side 54A to be removed from the underground outer wall 52, and the retaining wall 60 is composed of the new retaining wall 56 and the remaining underground outer wall 52.

Therefore, after dismantling and removing the part of the existing underground skeleton 50 outside the new retaining wall 56, the existing underground structure that was removed while constructing a new underground structure 64 having a smaller area than the existing underground structure of the existing building. Other structures and the like can be constructed in the portion where the skeleton 50 existed.

(Fourth Embodiment)
Next, the retaining pile according to the fourth embodiment of the present invention will be described with reference to FIG.

<Structure>
In the fourth embodiment, as shown in FIG. 4, of the existing underground skeleton 66 defining the underground space U, a part of the underground bottom slab 68 has been dismantled and removed, and a new retaining wall built in the vertical direction. The upper end of 70 is connected to the end of the remaining underground slab 68.

The new retaining wall 70 receives earth pressure and groundwater pressure acting on the part where a part of the removed underground bottom slab 68 existed, and the new retaining wall 70, the underground outer wall 72 of the existing underground skeleton 66, and the remaining underground retaining wall 70. The ridge 80 is constructed by the underground slab 68. Further, the underground space V, which is deeper than the underground space U, is defined by the retaining 80.

If the earth pressure or groundwater pressure acting on the new retaining wall 70 is low, it is not necessary to connect the new retaining wall 70 and the remaining underground bottom slab 68. Further, the position of the upper end portion of the new retaining wall 70 may be a position that wraps with the end portion of the underground bottom slab 68 when viewed from the horizontal direction, and the depth of the upper end surface of the new retaining wall 70 is the depth of the underground bottom slab 68. It may be shallower than the depth of the upper surface.

<How to build an underground structure>
When constructing a new underground structure 82 using the mountain retaining 80, first, while dismantling and removing the existing underground structure (not shown) of the existing building, a through hole (not shown) in the underground bottom slab 68 of the existing underground skeleton 66. To form.

Then, by building a plurality of piles such as steel sheet piles in the ground from the through hole by a pile driver (not shown) installed on the underground bottom slab 68, a new pile retaining wall 70 is constructed by the plurality of piles. Alternatively, a new pile wall 70 is constructed by covering the pile head of the pile with a yatko (temporary pile) and building the pile from the ground using the yatko.

Next, a part of the underground slab 68 located inside the new retaining wall 70 is dismantled and removed. Then, in the inside of the retaining wall 80 composed of the new retaining wall 70 and the underground outer wall 72, that is, in the underground space V, a new underground bottom slab of the new underground structure 82 is constructed at a position deeper than the underground bottom slab 68, and the new underground outer wall is constructed. Other new underground structures such as 64 will be constructed. The above process procedure is an example, and the order may change.

<Action, effect>
According to the present embodiment, a part of the underground bottom slab 68 is removed, and a new retaining wall 70 is constructed outside the removed underground bottom slab 68, that is, outside the underground space U. Therefore, the earth pressure and the groundwater pressure acting on the part where a part of the removed underground bottom slab 68 existed can be received by the new retaining wall 70.

Further, the underground space V deeper than the underground space U is defined by the earth retaining wall 80 composed of the newly constructed earth retaining wall 70 and the underground outer wall 72. Therefore, it is possible to construct a new underground structure 82 having a depth deeper than the existing underground structure of the existing building.

(Other embodiments)
Although an example of the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and various other embodiments are possible within the scope of the present invention.

For example, in the first embodiment, only one surface 14A of the underground outer wall 14 was removed, and the retaining wall 10 was constructed by the remaining underground outer walls 14B, 14C, 14D and the newly constructed retaining wall 16. However, the range to be removed from the existing underground skeleton 12 can be appropriately determined according to the size (area or depth) of the newly constructed underground structure 24.

Therefore, for example, the three sides of the underground outer wall 14 may be removed, and the retaining wall 10 may be constructed by the remaining one surface of the underground outer wall 14 and the newly constructed retaining wall 16. Further, the underground outer wall 14 of the existing underground skeleton 12 may be completely removed, and the retaining wall may be constructed by the underground bottom slab 18 of the existing underground skeleton 12 and the new retaining wall 16.

Similarly, in the fourth embodiment, a part of the underground bottom slab 68 of the existing underground skeleton 66 was removed, and the underground bottom slab 68 was constructed by the new underground retaining wall 70, the underground outer wall 72, and the remaining underground bottom slab 68. However, the underground bottom slab 68 may be completely removed, and the underground retaining wall 70 and the underground outer wall 72 of the existing underground skeleton 66 may be used to construct the retaining wall.

Further, in the second embodiment, the newly constructed retaining wall 38 is provided linearly along the underground outer walls 34 and 36 so as to connect the ends of the underground outer walls 34 and 36, respectively. However, the position, size, and shape of the new retaining wall 38 can be appropriately determined according to the size of the new underground structure 44 within the range in which the retaining wall 80 can be constructed together with the underground outer walls 34 and 36.

Therefore, for example, the new retaining wall 38 may be provided so as to wrap in the outer peripheral direction of the underground outer walls 34 and 36, or the new retaining wall 38 may be formed so as to project in the outer peripheral direction of the underground outer walls 34 and 36. ..

10, 40, 60, 80 Mountain retaining wall 12, 30, 50, 66 Existing underground skeleton 14, 34, 52, 72 Underground outer wall 16, 38, 56, 70 New underground retaining wall 18, 68 Underground slab 24, 44, 64, 82 New construction Underground structure 26 Existing underground structure 54A 1st underground slab (underground slab)
54B 2nd underground slab (underground slab)

Claims (2)

Two existing underground skeletons , which are arranged so as to be adjacent to each other at intervals and each of which has an underground outer wall facing each other removed,
A new retaining wall that is provided to connect the left and right ends of the underground outer walls left in each of the two existing underground skeletons facing each other and receives earth pressure, and
An underground space formed inside the remaining underground outer wall of the two existing underground skeletons and the new retaining wall, and a new underground structure is constructed.
With a mountain clasp. A process of installing a new retaining wall that receives earth pressure so as to connect the left and right ends of the underground outer walls facing each other, which are provided in each of the two existing underground skeletons arranged adjacent to each other at intervals.
The process of removing the underground outer walls facing each other provided in each of the two existing underground skeletons, and
The process of constructing a new underground structure inside the remaining underground outer wall of the two existing underground skeletons and the new retaining wall, and
How to build an underground structure with.